Accepted Manuscript Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap Xiaoju Zheng, MD, Canbin Zheng, MD, PhD, Baoshan Wang, MD, Yongfeng Qiu, MD, Zhong Zhang, MD, Haijun Li, MD, Xinhong Wang, MD PII:
S1743-9191(15)01420-X
DOI:
10.1016/j.ijsu.2015.12.035
Reference:
IJSU 2407
To appear in:
International Journal of Surgery
Received Date: 2 August 2015 Revised Date:
1 December 2015
Accepted Date: 11 December 2015
Please cite this article as: Zheng X, Zheng C, Wang B, Qiu Y, Zhang Z, Li H, Wang X, Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap, International Journal of Surgery (2016), doi: 10.1016/j.ijsu.2015.12.035. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Title: Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap Authors: Xiaoju Zheng1, MD; Canbin Zheng2*, MD, PhD; Baoshan Wang1, MD;
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Yongfeng Qiu1,3, MD; Zhong Zhang1, MD; Haijun Li1, MD; Xinhong Wang1, MD Affiliations of the authors: 1
Department of Hand and Podiatric Microsurgery, Xian Fengcheng Hospital, Xian,
Department of Microsurgery, Orthopedic Trauma and Hand Surgery, The First
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2
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P.R. China.
Affiliated Hospital of Sun Yat-sen University, Guangzhou, P.R. China. 3
The First Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang,
P.R. China.
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Correspondence to: Canbin Zheng, MD, PhD
Department of Microsurgery, Orthopedic Trauma and Hand Surgery The First Affiliated Hospital of Sun Yat-sen University
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58 Zhongshan Er Road, Guangzhou 510080, P.R. China.
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Phone: +86208755766-8242 Fax: +862087332150
E-mail: [email protected] Short title: Chimeric ALT perforator flap for extremity reconstruction Financial disclosure None of the authors has any commercial association or financial conflict regarding the data presented in this manuscript.
ACCEPTED MANUSCRIPT This work was supported by grants from National Natural Science Foundation of China (No.81401804), Science and Technology Planning Project of Guangdong Province, China (2014A020215008), Medical Scientific Research Foundation of
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Guangdong Province (No. B2014119).
ACCEPTED MANUSCRIPT Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap Abstract
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Introduction: The reconstruction of extensive three-dimensional defects in the extremities is a difficult challenge. Many attempts have been made to reconstruct such defects using the chimeric flap concept, enabling flaps with larger surface areas to be
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used while maintaining economical tissue use. The anterolateral thigh (ALT) chimeric
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flap is one of the most useful tools for the reconstruction of complex three-dimensional defects in the extremities.
Methods: From January 2010 to March 2012, Twenty-two patients underwent extremity reconstruction using chimeric ALT perforator flaps, which consists of a skin
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component on its isolated perforator and a portion of the fascia and muscle flaps on the same pedicle from the descending branch of the lateral circumflex femoral artery (LCFA). The defects were in either a lower (n=10) or an upper extremity (n=12). The
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area of the soft tissue defects ranged from 43 × 35 cm to 19 × 9 cm (mean, 25 × 18
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cm), containing extensive, irregular, ring-like soft tissue defects or degloving injuries. Results: The mean dimension of skin flap was 19.8 ×11.2 cm. The mean dimension of fascia flap was 8.9 × 7.1 cm. The mean dimension of muscle flap was 11.1 × 7.5 cm. No total flap loss occurred. One patient presented with venous thrombosis, and re-anastomosis and vein grafting were performed. Two cases exhibiting partial skin graft loss at the site at which the fascia flap was inset were treated via secondary skin grafts. During a follow-up period of 18 months to 30 months, patients were satisfied 1
ACCEPTED MANUSCRIPT with the functional and aesthetic outcome. No serious donor-site complications occurred. Discussion: Chimeric anterolateral thigh perforator flap can be one of the best choice
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for reconstruction of complex soft-tissue defects in the extremities. Conclusions: The various tissue components and maximal freedom offered by chimeric tissue flaps associated with the same descending branch of the LCFA
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provide versatile coverage of large, complex, and irregular soft-tissue defects in the
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extremities.
Keywords: Anterolateral thigh perforator flap; Lateral circumflex femoral artery;
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Free tissue transfer; Extremity
2
ACCEPTED MANUSCRIPT 1. Introduction The primary goal of extremity reconstruction is to restore and maintain extremity function, and skeletal reconstruction resulting in stable soft-tissue coverage is
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essential for achieving this goal. In cases of initial reconstruction failure, additional tissue and functionality might be lost[1]. Therefore, it is crucial to devise an appropriate treatment plan. However, reconstructing complex injuries of extremities
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containing extensive, irregular, ring-like soft tissue defects or degloving injuries
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remains a challenge for reconstructive microsurgeons, as very few flaps contain large amounts of tissue and multiple components are required to fulfill the functional and cosmetic requirements for correcting the recipient defect while inducing minimal donor-site morbidity.
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Since its first description by Song et al. in 1984, the anterolateral thigh (ALT) flap has become one of the most popular flaps for extensive soft-tissue defect reconstruction[2] because of its large skin area and reliability[3]. In addition, the ALT
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flap is versatile in that multiple tissue components can be harvested in various
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combinations and configurations, thus fulfilling all of the requirements for reconstruction[4]. For extensive, complex, and irregular wounds in the extremities, the chimeric ALT perforator flap is among the most popular members of the perforator flap family. A large tissue flap can be designed that includes multiple tissue components, such as muscle, fascia, and skin, each of which is supplied by a separate perforator based on the same lateral circumflex femoral artery (LCFA)[5]. This chimeric flap enables the use of multiple, spatially independent components of 3
ACCEPTED MANUSCRIPT various tissue types to reconstruct complex three-dimensional defects in the extremities via a single vascular anastomosis. From this chimeric flap, a small area of skin at the donor site can be harvested to yield the largest amount of tissue possible
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for the reconstruction of massive defects in the extremities with minimal loss of function at the donor site.
In this report, we describe the use of this technique for harvesting a chimeric ALT
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flap consisting of a skin component isolated on its perforator in combination with a
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portion of the fascia and/or muscle flaps, all of which are pedicled on the same descending branch of the LCFA, for the reconstruction of complex three-dimensional and massive defects in the extremities. 2. Materials and methods
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From January 2010 to March 2012, a total of 22 patients with large and complex three-dimensional defects in the extremities underwent reconstructive procedures that included chimeric ALT flap transfer. One patient was female, and 21 patients were
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male. The patients’ mean age was 36.5 years (range, 16 to 57 years). The mean body
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mass index was 25.2 ± 5.1 (range, 15.5 to 42.2). The mechanisms of injury were traffic accidents (n = 8) and industrial injuries (n = 14). The defects were in either a lower (n=10) or an upper extremity (n=12). In these 22 patients, the area of the soft tissue defects ranged from 43 × 35 cm to 19 × 9 cm (mean, 25 × 18 cm). In 10, six, five, and one patient, these flaps were used for the treatment of a traumatic limb amputation, a circumferential or near-circumferential de-gloving injury, or an open fracture with an associated skin defect or to cover a soft-tissue defect without a 4
ACCEPTED MANUSCRIPT fracture, respectively. The recipient site was the lower leg in five patients, the ankle and foot in five patients, the hand and fingers in six patients, and the forearm in six patients. Details related to these patients are provided in Table 1.
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2.1 Operative procedures All of the flaps were harvested in a similar manner. A line connecting the anterior superior iliac spine and the lateral border of the patella on the donor thigh with the
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patient in the supine position is drawn. The position of perforators usually around the
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midpoint of this line should be mapped with a Doppler probe. A longitudinal skin incision is made on the medial side of the flap. Then dissection is carried out over the deep fascia until the perforators are encountered. All the perforating branches of the descending or transverse LCFA in their intramuscular or intraseptal courses are
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identified at first. Elevation of the flap is continued by dissecting the descending branch toward the proximal and distal sides from the division of the perforator. Then, a minimum of two perforators from the descending branch of the LCFA are required
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to be preserved within the area of skin, fascia, or muscle to be included in the flap,
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and the perforators are freely dissected until the main trunk of the descending branch of the LCFA is reached (Fig. 1A). The chimeric ALT perforator flaps are designed and harvested based on findings during the operation and the reconstructive requirements of the recipient sites; Flap dimension is slightly larger than defect and slightly longer pedicle. These chimeric flaps should be designed to be included independent skin, fascia, or muscle flaps associated with the same descending branch of the LCFA. The skin and muscle flaps always contain individual paddles supplied by two separate 5
ACCEPTED MANUSCRIPT perforators. However, the fascia flap could be harvested by performing one of the following three types of dissection depended on the different origins of pedicle: Type I, in which the fascia flap is associated with one independent perforator that could be
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rotated up to 180°; Type II, in which the vascular pedicle of the fascia flap is a separate branch from the source vessel or is located on a side branch of the skin flap; or Type III, in which the many tiny perforators could not be freely dissected with the
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fascia flap, and a fascial pedicle with a width of 2 to 3 cm is required to ensure a
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sufficient blood supply (Fig. 1B-D). The muscle flaps are harvested from the partial vastus lateralis muscle, leaving the remaining muscle innervated and functionally intact. The entire flap can then be isolated on the two or more perforators and the descending branch of LCFA. The skin flaps are used to cover important tissues, such
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as vessels, nerves, and bones. The fascia flaps are used to cover tendinous tissues, followed by skin grafting. If the flap covered the soft tissue defect insufficiently or if severe contamination was caused by a bone defect or an empty cavity, an additional
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muscle flap is designed for additional bulk to eliminate any dead space or to enhance
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resistance to infection. If the injured extremities are associated with soft-tissue defect and major arterial damage, the pedicle vessels of the flap can be interposed into the vascular defect in the extremity to revascularise ischaemic extremities. The donor site can be closed primarily if the width was less than 8 cm, or with skin graft if the width was over 8 cm. The postoperative monitoring techniques include evaluation of color, capillary refill, turgor, surface temperature, presence of bleeding, skin graft adherence, and 6
ACCEPTED MANUSCRIPT auditory assessment of blood flow. The flaps should be monitored frequently, especially in the initial postoperative period. Emergent exploration and repair must be performed soon after obstruction occurs if it is to be successful.
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3. Results The skin flap dimensions ranged from 33 × 13 cm to 8 × 7 cm (mean, 19.8±7.6 ×11.2±3.2 cm). The fascia flap dimensions ranged from 15 × 10 cm to 6 × 4cm
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(mean, 8.9±3.3 × 7.1±2.0 cm). The muscle flap dimensions ranged from 22 × 12 cm
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to 6 × 4 cm (mean, 11.1±5.3 × 7.5±2.5cm). There were 14 cases in which a Type I flap was used, 5 cases in which a Type II flap was used, and 3 cases in which a Type III flap was used (Table 2). The mean surgery duration for flap harvesting was 5.4± 1.3 hours.
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One case exhibited a vascular complication (venous thrombosis). In this case, a thrombus was evident at the site of anastomosis. Therefore, the thrombus was removed immediately, and re-anastomosis and vein grafting were performed.
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Reperfusion was achieved, and only the partial margin of the 3 × 4 cm skin flap
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exhibited necrosis. On postoperative day 14, this patient was treated with a split-thickness skin graft. In total, two cases exhibiting partial skin graft loss at the site at which the fascia flap was inset were treated via secondary skin grafts. The remaining 19 cases did not experience vascular or recipient site complications. In our study, flow-through ALT flaps were designed in nine cases that involved major artery damage. The limbs of eight of these cases were successfully salvaged; the only case of limb loss involved a 54-year-old man who was the victim of a traffic accident, and 7
ACCEPTED MANUSCRIPT this case involved degloving injuries and a completely severed left forearm. Replantation was performed, and a flow-through ALT perforator flap was transferred to reconstruct the radial artery and to cover the massive soft tissue loss. On
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postoperative day 6, the distal left forearm became necrotic, and the patient underwent amputation. However, the ALT flap survived and was used to cover the stump.
Over the 18 months to 30 months (mean, 24 months) of follow-up in this study,
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the flaps remained viable, and the wounds healed well, including reliable soft tissue
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and good contour in the reconstructed areas. Skin grafts over the fascia or muscle layers developed very well (i.e., smoothly with great elasticity, no recoil, and no change in color). Three patients received subsequent flap debulking. All of the donor sites were closed using split-thickness skin grafts. Among the 22 patients, there were
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no complications at the donor sites that required surgical treatment. No patients experienced any difficulty in activities of daily living, and none of the patients suffered from knee extension lag. No patients experienced restrictions in climbing
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stairs. Only six patients experienced transient limb weakness. These six patients
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typically regained their preoperative range of mobility and activity level within six months. The appearance of the donor site was considered to be satisfactory by 18 patients and acceptable by four patients. 3.1 Case report Case 1 A 20-year-old man involved in a traffic accident sustained an injury to the right lower limb. He presented with open ankle joint dislocation and irregular and extensive 8
ACCEPTED MANUSCRIPT soft tissue defects measuring 43 × 35 cm on the distal leg (Fig. 2A, B). In addition, both the anterior and posterior tibial arteries were ruptured, resulting in impaired distal leg and foot circulation.
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Two teams worked together to perform the operation. The ankle joint dislocation was reduced and fixed using pins. Subsequently, the ruptured posterior tibial artery was repaired using a great saphenous vein graft to restore the blood supply. Based on
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the size and characteristics of the wounds, a chimeric ALT perforator flap was
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harvested that consisted of a skin component, a partial vastus lateralis muscle component, and a fascial pedicle on the left descending branch of the LCFA (Fig. 2C). The majority of the vastus lateralis muscle remained in situ and functionally intact. The skin paddle was 32 × 13 cm; the fascia flap was 15 × 10 cm; and the muscle flap
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was 10 × 8 cm. The skin flap was applied to the anteromedial surface of the leg to cover the underlying gliding tissues and exposed tendons. The muscle flap covered the posterior surface, whereas the fascia flap covered the lateral surface (Fig. 2D, E).
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The pedicle vessels and the descending branch were interposed between the two ends
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of the anterior tibial artery, which exhibited a 3-cm gap. The muscle and fascia flaps were covered by a skin graft. The donor site was closed using a skin graft. The flap survived in its entirety;
partial skin graft loss was treated via a secondary skin graft. The patient was not satisfied with the appearance of the flaps and received secondary flap debulking after 5 months. The final follow-up occurred at 18 months (Fig. 2F). The functional recovery of the lower limb was satisfactory. 9
ACCEPTED MANUSCRIPT Case 2 A 20-year-old man sustained an incompletely severed right ankle with an extensive soft tissue defect as a result of a traffic accident. A 30 × 24 cm soft tissue
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defect was present after debridement, open reduction, and internal fixation (Fig. 3A, B). The posterior tibial artery was immediately repaired using a vein graft. A large free chimeric ALT flap consisting of a skin flap (18 × 12 cm), a fascia flap (12 × 10
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cm), and a muscle flap (8 × 6 cm) was harvested with its associated perforators (Fig.
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3C). Based on the size and characteristics of the wound, the skin flap covered the anterolateral surface of the wound; the fascia flap covered the medial surface of the wound; and the muscle flap covered the posterior surface of the wound (Fig. 3D, E). Vascular flow-through anastomosis was performed on the anterior tibial vessels. The
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defatted glabrous skin was repositioned using a full-sheet skin graft. The ipsilateral donor site was grafted using a split-thickness skin graft. The flap survived in its entirety without any major complications (Fig. 3F). Partial skin graft
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loss occurred at the sites at which the fascia flap was inset; this loss was treated via a
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secondary skin graft. The patient recovered partial motion of the ankle joint. 4. Discussion
Large and complex traumatic defects in the extremity remain a challenge for
surgeons with restoration of function with minimal donor-site morbidity being the surgical goals. Traditionally, latissimus dorsi, thoracodorsal flap and rectus abdominis muscle flap have been used for the reconstruction of larger defects[6]. Compared with the thoracic or trunk areas as donor site, an often-cited benefit of the ALT flap is the 10
ACCEPTED MANUSCRIPT minimal loss of function and the cosmetically acceptable donor site, which is covered by normal clothing[7]. In our department, the ALT flap is extensively used for the reconstruction of complex defects of the upper or lower extremities. However, the
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repair of extensive, irregular, ring-like soft tissue defects or degloving injuries of the extremities using classic ALT flaps is difficult. Based on the recently developed perforator flap concept, if more than one perforator is available, the ALT flap can be
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separated into several different tissue flaps; each flap is based on a single perforator.
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This ALT flap design, referred to as a compound flap or a chimeric perforator flap, is a modification of the classic ALT flap in which a small area of skin is harvested at the donor site to yield the largest amount of tissue possible for the reconstruction of extensive, irregular, and complex defects via a single vascular anastomosis while
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inducing minimal loss of function[8, 9]. And this chimeric ALT flap is versatile for the reconstruction of three-dimensional defects in the extremities. Because different tissue flaps contain perforators that are independent from the main trunk of the descending
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branch of the LCFA, it is easy to cover extensive and irregular wounds freely in
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various directions; thus, complex three-dimensional defects can be reconstructed. Based on chimeric flap and perforator dissection technique, Peng et al. described their experience with the use of chimeric ALT perforator flaps to simultaneously reconstruct two separate defects in the upper extremity[5]. Chou et al. reported that two fasciocutaneous flaps associated with independent skin vessels could be reliably harvested from the same descending branch of the LCFA for the simultaneous reconstruction of two separate defects.[10] Both groups split the skin paddle between 11
ACCEPTED MANUSCRIPT the perforators to generate two separate paddles with a common vascular supply. Jiang et al also reported one tripaddled ALT flap for reconstruction of bilateral buccal defects created from cancer ablation and severe contralateral oral submucous fibrosis
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release[11]. However, few reports are available that describe the simultaneous reconstruction of more extensive, complex, and irregular defects using three different tissue flaps from the same descending branch of the LCFA. The design of flap
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allowed the three or two independent flaps easier to inset for reconstruction of
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complex defects.
In this report, we present the results of the use of chimeric ALT perforator flaps, which enabled the development of two or three independent free tissue flaps based on the same descending branch of the LCFA. This chimeric ALT perforator flap was
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designed for extremity reconstruction, considering the size and characteristics of the soft tissue defects and the location and characteristics of the recipient sites.[12] For large defect areas, we primarily used the skin flap to cover sites containing nerves or
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vessels. For small defect areas or less important sites, we primarily used fascia flaps
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and subsequently covered the site with a split skin graft. In cases of overly large defects for which the two aforementioned flaps were insufficient or in cases of cavity or bone exposure repair, bone defects, or severe contamination, we performed the reconstruction using an additional muscle flap. Muscle tissue is highly vascular and, thus, is highly resistant to infection[1, 13, 14]. In some cases of severe injury to the extremities, deep defects may be associated with major arterial damage, leading to poor perfusion of the distal region of the limb. Flow-through flaps appear to represent 12
ACCEPTED MANUSCRIPT the best option in these situations because such flaps enable simultaneous arterial reconstruction and soft-tissue coverage[15]. The chimeric ALT perforator flap can be utilized for extremity reconstruction as a flow-through flap in which the pedicle
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bridges the vascular gaps[16]. In our study, flow-through ALT perforator flaps were designed in 9 cases. Vascular flow-through anastomosis was performed on the main trunk of the vessels to provide simultaneous arterial reconstruction and soft-tissue
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coverage of the extremity. In the majority of cases, the muscle, fascia, and skin flaps
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were generated completely independently by dissecting muscle, fascia, and skin on separate, individual perforators. In the vastus lateralis muscle, most of the large muscle branches emanating from the myocutaneous perforators run medially, laterally, and posteriorly from the descending branch, and flap harvesting can be completed via
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the standard method[17]. In some cases, the main pedicle associated with the fascia flap originated from the perforators of the skin flap and did not directly originate from the descending branch of the LCFA. In some cases, there were many tiny perforators
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that could not be freely dissected with the fascia flap; in these cases, a pedicle that
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was 2 to 3 cm wide was preserved to ensure the circulation of the flap. In the latter two types of flaps, a similar freedom of rotation could still be achieved when the skin and muscle islands were isolated on an individual perforator. Before surgery, we routinely performed assessment via hand-held Doppler flowmetry to reduce the uncertainty caused by variations in the vascular anatomy. The authors with the most experience in this procedure recommended this procedure[18, 19]. The localization and course of the perforators could be determined accurately, and vascular anomalies 13
ACCEPTED MANUSCRIPT could be identified[20]. During surgery, all of the perforators from the descending branch of the LCFA should be identified and preserved. We suggest that these complex chimeric flaps are ideally dissected from the pedicle to the various tissue
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components of the chimeric flap. The initial dissection of the vascular pedicle facilitates the identification of any vascular anomalies and the assessment of the quantity and quality of the perforators while the extirpative surgeon is completing the
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resection[21].
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This type of chimeric ALT perforator flaps provides several benefits. First, a minimal area of skin is harvested at the donor site to provide the largest amount of tissue possible for the coverage of a massive soft tissue defect with minimal loss of function and good cosmetic acceptability at the donor site. Second, the various
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paddles can be inset with many degrees of freedom, facilitating the coverage of complex and extensive three-dimensional defects in the extremities. Third, the various tissue components can be used for the reconstruction of complex extremity defects
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that include multiple tissue structural requirements. Finally, this flap can be designed
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with minimal effort and operation time as well as one pair of recipient vessels[22]. A disadvantage of the chimeric ALT perforator flap technique is that it requires advanced skill. The course of the perforators can be unpredictable, and small or long perforators can be difficult to harvest and inset. The microsurgeon must have superior microsurgical skills and must be familiar with perforator flaps and intramuscular perforator dissection[23]. Finally, for such extensive and complex soft tissue defects, we suggest a two-team surgery, during which the teams performing resection and 14
ACCEPTED MANUSCRIPT reconstruction operate in parallel to reduce the operation time. Our study is subject to the limitations inherent in retrospective, uncontrolled case reviews, including a small sample size, no strict criteria for patient selection, and no
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prospective data collection, especially a final strict functional assessment. 5. Conlusions
In summary, the chimeric ALT perforator flap, which is a novel variation of the
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standard ALT flap design, was found to provide large tissue components that are
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versatile and valuable. This technique facilitates the harvest of various tissue components with maximal freedom, providing maximal flexibility to meet specific reconstructive requirements for large, complex, and irregular soft-tissue defects in the extremities.
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Ethical approval
All studies have been approved by both the First Affiliated Hospital of Sun Yat-sen University and Xian Fengcheng Hospital Ethics Committee and performed in
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accordance with the ethical standards.
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Financial support None.
Author contribution
Canbin Zheng participated in the design of the operation and study, and drafted
the manuscript. Xiaoju Zheng carried out the operation, together with Canbin Zheng and helped to draft the manuscript. Baoshan Wang took charge of collecting the patients’ data and helped to perform the operation. Yongfeng Qiu took charge of 15
ACCEPTED MANUSCRIPT recruiting patients and helped to design the study. Zhong Zhang and Haijun Li followed up all the patients and analyzed the data. Xinhong Wang collected important background information. All authors read and approved the final manuscript.
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Conflicts of interest None Guarantor
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Canbin Zheng
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Acknowledgements
This work was supported by grants from National Natural Science Foundation of China (No.81401804), Science and Technology Planning Project of Guangdong Province, China (2014A020215008), Medical Scientific Research Foundation of
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32 (2012) 318-321.
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ACCEPTED MANUSCRIPT Figure Legends Fig. 1. (A) Perforators in the muscle, fascia, and skin from the descending branch of the LCFA. Three strategies were used to dissect the fascia flap. (B) Type I: the
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harvested free chimeric ALT perforator flap, consisting of skin, fascia, and muscle flaps, was associated with independent perforators from the descending branch of the LCFA. (C) Type II: the vascular pedicle of the fascia flap was a separate branch from
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the source vessel or was located on a side branch of the skin flap. (D) Type III: many
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tiny perforators could not be freely dissected with the fascia flap, so a 2- to 3-cm-wide fascial pedicle was preserved during harvesting.
Fig. 2. A 20-year-old man experienced an open dislocation of the ankle joint caused by a traffic accident. (A, B) Intraoperative view showing a 43 × 35 cm circular soft
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tissue defect. (C) Intraoperative view of the chimeric free ALT flap. (D, E) Intraoperative photographs revealing the different components that were placed in situ. (F) The well-healed wound at the 3-month follow-up.
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Fig. 3. A 20-year-old man sustained an incompletely severed right ankle with a large
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soft tissue defect as a result of a traffic accident. (A, B) Intraoperative imaging demonstrated a massive soft tissue defect with incomplete severing of the ankle. (C) A free chimeric ALT perforator flap was harvested to provide soft tissue coverage. (D, E) Intraoperative view after final anterolateral thigh flap insetting. Repositioning of the defatted glabrous skin as a full-sheet skin graft. (F) A satisfactory result was demonstrated at the 10-month follow-up.
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ACCEPTED MANUSCRIPT Table 1. Patient data
20/M 2
34/M 3
20/M 4
20/M
8 9 10
11 12 13 14
16
17 18
Lower leg
18 × 12
None
Complete
Lower leg
36 × 28
Lower leg
43 × 35
Lower leg
30 × 24
25/M Crush injury
Foot
16/M Crush injury 57/M Crush injury 38/M Crush injury Motor 37/M vehicle accident 37/M Crush injury 23/M Crush injury 21/M Crush injury
45/M Crush injury
15
Flap survival
35/M Crush injury
34 × 18
Dorsum: 7 × 6 Palm：7.5×6 Distal forearm Palm: 10 × 5 + hand Dorsum: 9 × 4 Palm: 12 × 8 Hand Dorsum: 10 × 5 Distal forearm 20 × 28
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7
Comorbidi ty
Lower leg
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6
Soft-tissue defect (cm2)
17/M Crush injury
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5
Motor vehicle accident Motor vehicle accident Motor vehicle accident Motor vehicle accident
Wound location
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1
Etiology
Distal forearm
30 × 25
Distal forearm
15 × 25 Palm: 9 × 5 Hand Dorsum: 7 × 6 Distal forearm Palm: 14 × 8 + hand Dorsum: 8 × 6 Palm: 16 × 10 Wrist + hand Dorsum: 16 × 10 Palm: 18 × 9 Hand Dorsum: 8 × 5
Motor 52/M vehicle accident
Ankle + foot
20/M Crush injury
Foot
40/M Crush injury
Ankle + foot
None
Complete
None
Complete
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Age/se x
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Case no.
Dorsum: 12 × 8 Pelma：11 × 7 Dorsum: 10 × 8 Pelma：8 × 6 Dorsum: 6 × 6
None
Complete
None
Partial skin graft loss
None
Complete
None
Complete
None
Complete
None
Complete
None
Partial skin graft loss
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
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17 /F Crush injury
Wrist + hand
Distal forearm
None
Complete
None
Complete
Dorsum: 12×10 Palm: 12×8
Hyperten sion
Complete
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Motor 54/M vehicle accident M, male; F, female
Palm: 9 × 8 Wrist: 6 × 4 Dorsum: 15 × 8 Palm: 8 × 7
Complete
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Wrist + hand
Dorsum: 6 × 5 Pelma：30 × 12 None
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22
42/M Crush injury
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21
Ankle + foot
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20
Motor 42/M vehicle accident
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ACCEPTED MANUSCRIPT Table 2 Flap type, recipient site, and complication Complication Flap survival
14 5 3
14 5 3
2 0 0
10 12
10 12
1 1
Partial skin Venous thrombosis graft loss 1 0 0
1 0
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Flap type Type I Type II Type III Recipient site Lower extremity Upper extremity
No. of patients
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Flap type or recipient site
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ACCEPTED MANUSCRIPT Highlights: 1.
Clinical reports have described successful use of the chimeric ALT perforator flap for reconstruction of complex soft-tissue defects in the extremities. This technique facilitates the harvest of various tissue components with maximal
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2.
freedom, providing maximal flexibility to meet specific reconstructive requirements for large, complex, and irregular soft-tissue defects in the
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three types of dissection.
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The chimeric ALT perforator flap could be harvested by performing one of the
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3.
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extremities.
S1743-9191(15)01420-X
DOI:
10.1016/j.ijsu.2015.12.035
Reference:
IJSU 2407
To appear in:
International Journal of Surgery
Received Date: 2 August 2015 Revised Date:
1 December 2015
Accepted Date: 11 December 2015
Please cite this article as: Zheng X, Zheng C, Wang B, Qiu Y, Zhang Z, Li H, Wang X, Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap, International Journal of Surgery (2016), doi: 10.1016/j.ijsu.2015.12.035. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Title: Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap Authors: Xiaoju Zheng1, MD; Canbin Zheng2*, MD, PhD; Baoshan Wang1, MD;
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Yongfeng Qiu1,3, MD; Zhong Zhang1, MD; Haijun Li1, MD; Xinhong Wang1, MD Affiliations of the authors: 1
Department of Hand and Podiatric Microsurgery, Xian Fengcheng Hospital, Xian,
Department of Microsurgery, Orthopedic Trauma and Hand Surgery, The First
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2
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P.R. China.
Affiliated Hospital of Sun Yat-sen University, Guangzhou, P.R. China. 3
The First Affiliated Hospital of Shaanxi University of Chinese Medicine, Xianyang,
P.R. China.
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Correspondence to: Canbin Zheng, MD, PhD
Department of Microsurgery, Orthopedic Trauma and Hand Surgery The First Affiliated Hospital of Sun Yat-sen University
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58 Zhongshan Er Road, Guangzhou 510080, P.R. China.
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Phone: +86208755766-8242 Fax: +862087332150
E-mail: [email protected] Short title: Chimeric ALT perforator flap for extremity reconstruction Financial disclosure None of the authors has any commercial association or financial conflict regarding the data presented in this manuscript.
ACCEPTED MANUSCRIPT This work was supported by grants from National Natural Science Foundation of China (No.81401804), Science and Technology Planning Project of Guangdong Province, China (2014A020215008), Medical Scientific Research Foundation of
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Guangdong Province (No. B2014119).
ACCEPTED MANUSCRIPT Reconstruction of complex soft-tissue defects in the extremities with chimeric anterolateral thigh perforator flap Abstract
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Introduction: The reconstruction of extensive three-dimensional defects in the extremities is a difficult challenge. Many attempts have been made to reconstruct such defects using the chimeric flap concept, enabling flaps with larger surface areas to be
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used while maintaining economical tissue use. The anterolateral thigh (ALT) chimeric
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flap is one of the most useful tools for the reconstruction of complex three-dimensional defects in the extremities.
Methods: From January 2010 to March 2012, Twenty-two patients underwent extremity reconstruction using chimeric ALT perforator flaps, which consists of a skin
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component on its isolated perforator and a portion of the fascia and muscle flaps on the same pedicle from the descending branch of the lateral circumflex femoral artery (LCFA). The defects were in either a lower (n=10) or an upper extremity (n=12). The
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area of the soft tissue defects ranged from 43 × 35 cm to 19 × 9 cm (mean, 25 × 18
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cm), containing extensive, irregular, ring-like soft tissue defects or degloving injuries. Results: The mean dimension of skin flap was 19.8 ×11.2 cm. The mean dimension of fascia flap was 8.9 × 7.1 cm. The mean dimension of muscle flap was 11.1 × 7.5 cm. No total flap loss occurred. One patient presented with venous thrombosis, and re-anastomosis and vein grafting were performed. Two cases exhibiting partial skin graft loss at the site at which the fascia flap was inset were treated via secondary skin grafts. During a follow-up period of 18 months to 30 months, patients were satisfied 1
ACCEPTED MANUSCRIPT with the functional and aesthetic outcome. No serious donor-site complications occurred. Discussion: Chimeric anterolateral thigh perforator flap can be one of the best choice
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for reconstruction of complex soft-tissue defects in the extremities. Conclusions: The various tissue components and maximal freedom offered by chimeric tissue flaps associated with the same descending branch of the LCFA
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provide versatile coverage of large, complex, and irregular soft-tissue defects in the
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extremities.
Keywords: Anterolateral thigh perforator flap; Lateral circumflex femoral artery;
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Free tissue transfer; Extremity
2
ACCEPTED MANUSCRIPT 1. Introduction The primary goal of extremity reconstruction is to restore and maintain extremity function, and skeletal reconstruction resulting in stable soft-tissue coverage is
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essential for achieving this goal. In cases of initial reconstruction failure, additional tissue and functionality might be lost[1]. Therefore, it is crucial to devise an appropriate treatment plan. However, reconstructing complex injuries of extremities
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containing extensive, irregular, ring-like soft tissue defects or degloving injuries
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remains a challenge for reconstructive microsurgeons, as very few flaps contain large amounts of tissue and multiple components are required to fulfill the functional and cosmetic requirements for correcting the recipient defect while inducing minimal donor-site morbidity.
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Since its first description by Song et al. in 1984, the anterolateral thigh (ALT) flap has become one of the most popular flaps for extensive soft-tissue defect reconstruction[2] because of its large skin area and reliability[3]. In addition, the ALT
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flap is versatile in that multiple tissue components can be harvested in various
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combinations and configurations, thus fulfilling all of the requirements for reconstruction[4]. For extensive, complex, and irregular wounds in the extremities, the chimeric ALT perforator flap is among the most popular members of the perforator flap family. A large tissue flap can be designed that includes multiple tissue components, such as muscle, fascia, and skin, each of which is supplied by a separate perforator based on the same lateral circumflex femoral artery (LCFA)[5]. This chimeric flap enables the use of multiple, spatially independent components of 3
ACCEPTED MANUSCRIPT various tissue types to reconstruct complex three-dimensional defects in the extremities via a single vascular anastomosis. From this chimeric flap, a small area of skin at the donor site can be harvested to yield the largest amount of tissue possible
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for the reconstruction of massive defects in the extremities with minimal loss of function at the donor site.
In this report, we describe the use of this technique for harvesting a chimeric ALT
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flap consisting of a skin component isolated on its perforator in combination with a
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portion of the fascia and/or muscle flaps, all of which are pedicled on the same descending branch of the LCFA, for the reconstruction of complex three-dimensional and massive defects in the extremities. 2. Materials and methods
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From January 2010 to March 2012, a total of 22 patients with large and complex three-dimensional defects in the extremities underwent reconstructive procedures that included chimeric ALT flap transfer. One patient was female, and 21 patients were
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male. The patients’ mean age was 36.5 years (range, 16 to 57 years). The mean body
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mass index was 25.2 ± 5.1 (range, 15.5 to 42.2). The mechanisms of injury were traffic accidents (n = 8) and industrial injuries (n = 14). The defects were in either a lower (n=10) or an upper extremity (n=12). In these 22 patients, the area of the soft tissue defects ranged from 43 × 35 cm to 19 × 9 cm (mean, 25 × 18 cm). In 10, six, five, and one patient, these flaps were used for the treatment of a traumatic limb amputation, a circumferential or near-circumferential de-gloving injury, or an open fracture with an associated skin defect or to cover a soft-tissue defect without a 4
ACCEPTED MANUSCRIPT fracture, respectively. The recipient site was the lower leg in five patients, the ankle and foot in five patients, the hand and fingers in six patients, and the forearm in six patients. Details related to these patients are provided in Table 1.
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2.1 Operative procedures All of the flaps were harvested in a similar manner. A line connecting the anterior superior iliac spine and the lateral border of the patella on the donor thigh with the
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patient in the supine position is drawn. The position of perforators usually around the
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midpoint of this line should be mapped with a Doppler probe. A longitudinal skin incision is made on the medial side of the flap. Then dissection is carried out over the deep fascia until the perforators are encountered. All the perforating branches of the descending or transverse LCFA in their intramuscular or intraseptal courses are
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identified at first. Elevation of the flap is continued by dissecting the descending branch toward the proximal and distal sides from the division of the perforator. Then, a minimum of two perforators from the descending branch of the LCFA are required
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to be preserved within the area of skin, fascia, or muscle to be included in the flap,
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and the perforators are freely dissected until the main trunk of the descending branch of the LCFA is reached (Fig. 1A). The chimeric ALT perforator flaps are designed and harvested based on findings during the operation and the reconstructive requirements of the recipient sites; Flap dimension is slightly larger than defect and slightly longer pedicle. These chimeric flaps should be designed to be included independent skin, fascia, or muscle flaps associated with the same descending branch of the LCFA. The skin and muscle flaps always contain individual paddles supplied by two separate 5
ACCEPTED MANUSCRIPT perforators. However, the fascia flap could be harvested by performing one of the following three types of dissection depended on the different origins of pedicle: Type I, in which the fascia flap is associated with one independent perforator that could be
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rotated up to 180°; Type II, in which the vascular pedicle of the fascia flap is a separate branch from the source vessel or is located on a side branch of the skin flap; or Type III, in which the many tiny perforators could not be freely dissected with the
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fascia flap, and a fascial pedicle with a width of 2 to 3 cm is required to ensure a
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sufficient blood supply (Fig. 1B-D). The muscle flaps are harvested from the partial vastus lateralis muscle, leaving the remaining muscle innervated and functionally intact. The entire flap can then be isolated on the two or more perforators and the descending branch of LCFA. The skin flaps are used to cover important tissues, such
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as vessels, nerves, and bones. The fascia flaps are used to cover tendinous tissues, followed by skin grafting. If the flap covered the soft tissue defect insufficiently or if severe contamination was caused by a bone defect or an empty cavity, an additional
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muscle flap is designed for additional bulk to eliminate any dead space or to enhance
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resistance to infection. If the injured extremities are associated with soft-tissue defect and major arterial damage, the pedicle vessels of the flap can be interposed into the vascular defect in the extremity to revascularise ischaemic extremities. The donor site can be closed primarily if the width was less than 8 cm, or with skin graft if the width was over 8 cm. The postoperative monitoring techniques include evaluation of color, capillary refill, turgor, surface temperature, presence of bleeding, skin graft adherence, and 6
ACCEPTED MANUSCRIPT auditory assessment of blood flow. The flaps should be monitored frequently, especially in the initial postoperative period. Emergent exploration and repair must be performed soon after obstruction occurs if it is to be successful.
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3. Results The skin flap dimensions ranged from 33 × 13 cm to 8 × 7 cm (mean, 19.8±7.6 ×11.2±3.2 cm). The fascia flap dimensions ranged from 15 × 10 cm to 6 × 4cm
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(mean, 8.9±3.3 × 7.1±2.0 cm). The muscle flap dimensions ranged from 22 × 12 cm
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to 6 × 4 cm (mean, 11.1±5.3 × 7.5±2.5cm). There were 14 cases in which a Type I flap was used, 5 cases in which a Type II flap was used, and 3 cases in which a Type III flap was used (Table 2). The mean surgery duration for flap harvesting was 5.4± 1.3 hours.
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One case exhibited a vascular complication (venous thrombosis). In this case, a thrombus was evident at the site of anastomosis. Therefore, the thrombus was removed immediately, and re-anastomosis and vein grafting were performed.
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Reperfusion was achieved, and only the partial margin of the 3 × 4 cm skin flap
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exhibited necrosis. On postoperative day 14, this patient was treated with a split-thickness skin graft. In total, two cases exhibiting partial skin graft loss at the site at which the fascia flap was inset were treated via secondary skin grafts. The remaining 19 cases did not experience vascular or recipient site complications. In our study, flow-through ALT flaps were designed in nine cases that involved major artery damage. The limbs of eight of these cases were successfully salvaged; the only case of limb loss involved a 54-year-old man who was the victim of a traffic accident, and 7
ACCEPTED MANUSCRIPT this case involved degloving injuries and a completely severed left forearm. Replantation was performed, and a flow-through ALT perforator flap was transferred to reconstruct the radial artery and to cover the massive soft tissue loss. On
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postoperative day 6, the distal left forearm became necrotic, and the patient underwent amputation. However, the ALT flap survived and was used to cover the stump.
Over the 18 months to 30 months (mean, 24 months) of follow-up in this study,
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the flaps remained viable, and the wounds healed well, including reliable soft tissue
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and good contour in the reconstructed areas. Skin grafts over the fascia or muscle layers developed very well (i.e., smoothly with great elasticity, no recoil, and no change in color). Three patients received subsequent flap debulking. All of the donor sites were closed using split-thickness skin grafts. Among the 22 patients, there were
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no complications at the donor sites that required surgical treatment. No patients experienced any difficulty in activities of daily living, and none of the patients suffered from knee extension lag. No patients experienced restrictions in climbing
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stairs. Only six patients experienced transient limb weakness. These six patients
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typically regained their preoperative range of mobility and activity level within six months. The appearance of the donor site was considered to be satisfactory by 18 patients and acceptable by four patients. 3.1 Case report Case 1 A 20-year-old man involved in a traffic accident sustained an injury to the right lower limb. He presented with open ankle joint dislocation and irregular and extensive 8
ACCEPTED MANUSCRIPT soft tissue defects measuring 43 × 35 cm on the distal leg (Fig. 2A, B). In addition, both the anterior and posterior tibial arteries were ruptured, resulting in impaired distal leg and foot circulation.
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Two teams worked together to perform the operation. The ankle joint dislocation was reduced and fixed using pins. Subsequently, the ruptured posterior tibial artery was repaired using a great saphenous vein graft to restore the blood supply. Based on
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the size and characteristics of the wounds, a chimeric ALT perforator flap was
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harvested that consisted of a skin component, a partial vastus lateralis muscle component, and a fascial pedicle on the left descending branch of the LCFA (Fig. 2C). The majority of the vastus lateralis muscle remained in situ and functionally intact. The skin paddle was 32 × 13 cm; the fascia flap was 15 × 10 cm; and the muscle flap
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was 10 × 8 cm. The skin flap was applied to the anteromedial surface of the leg to cover the underlying gliding tissues and exposed tendons. The muscle flap covered the posterior surface, whereas the fascia flap covered the lateral surface (Fig. 2D, E).
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The pedicle vessels and the descending branch were interposed between the two ends
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of the anterior tibial artery, which exhibited a 3-cm gap. The muscle and fascia flaps were covered by a skin graft. The donor site was closed using a skin graft. The flap survived in its entirety;
partial skin graft loss was treated via a secondary skin graft. The patient was not satisfied with the appearance of the flaps and received secondary flap debulking after 5 months. The final follow-up occurred at 18 months (Fig. 2F). The functional recovery of the lower limb was satisfactory. 9
ACCEPTED MANUSCRIPT Case 2 A 20-year-old man sustained an incompletely severed right ankle with an extensive soft tissue defect as a result of a traffic accident. A 30 × 24 cm soft tissue
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defect was present after debridement, open reduction, and internal fixation (Fig. 3A, B). The posterior tibial artery was immediately repaired using a vein graft. A large free chimeric ALT flap consisting of a skin flap (18 × 12 cm), a fascia flap (12 × 10
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cm), and a muscle flap (8 × 6 cm) was harvested with its associated perforators (Fig.
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3C). Based on the size and characteristics of the wound, the skin flap covered the anterolateral surface of the wound; the fascia flap covered the medial surface of the wound; and the muscle flap covered the posterior surface of the wound (Fig. 3D, E). Vascular flow-through anastomosis was performed on the anterior tibial vessels. The
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defatted glabrous skin was repositioned using a full-sheet skin graft. The ipsilateral donor site was grafted using a split-thickness skin graft. The flap survived in its entirety without any major complications (Fig. 3F). Partial skin graft
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loss occurred at the sites at which the fascia flap was inset; this loss was treated via a
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secondary skin graft. The patient recovered partial motion of the ankle joint. 4. Discussion
Large and complex traumatic defects in the extremity remain a challenge for
surgeons with restoration of function with minimal donor-site morbidity being the surgical goals. Traditionally, latissimus dorsi, thoracodorsal flap and rectus abdominis muscle flap have been used for the reconstruction of larger defects[6]. Compared with the thoracic or trunk areas as donor site, an often-cited benefit of the ALT flap is the 10
ACCEPTED MANUSCRIPT minimal loss of function and the cosmetically acceptable donor site, which is covered by normal clothing[7]. In our department, the ALT flap is extensively used for the reconstruction of complex defects of the upper or lower extremities. However, the
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repair of extensive, irregular, ring-like soft tissue defects or degloving injuries of the extremities using classic ALT flaps is difficult. Based on the recently developed perforator flap concept, if more than one perforator is available, the ALT flap can be
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separated into several different tissue flaps; each flap is based on a single perforator.
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This ALT flap design, referred to as a compound flap or a chimeric perforator flap, is a modification of the classic ALT flap in which a small area of skin is harvested at the donor site to yield the largest amount of tissue possible for the reconstruction of extensive, irregular, and complex defects via a single vascular anastomosis while
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inducing minimal loss of function[8, 9]. And this chimeric ALT flap is versatile for the reconstruction of three-dimensional defects in the extremities. Because different tissue flaps contain perforators that are independent from the main trunk of the descending
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branch of the LCFA, it is easy to cover extensive and irregular wounds freely in
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various directions; thus, complex three-dimensional defects can be reconstructed. Based on chimeric flap and perforator dissection technique, Peng et al. described their experience with the use of chimeric ALT perforator flaps to simultaneously reconstruct two separate defects in the upper extremity[5]. Chou et al. reported that two fasciocutaneous flaps associated with independent skin vessels could be reliably harvested from the same descending branch of the LCFA for the simultaneous reconstruction of two separate defects.[10] Both groups split the skin paddle between 11
ACCEPTED MANUSCRIPT the perforators to generate two separate paddles with a common vascular supply. Jiang et al also reported one tripaddled ALT flap for reconstruction of bilateral buccal defects created from cancer ablation and severe contralateral oral submucous fibrosis
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release[11]. However, few reports are available that describe the simultaneous reconstruction of more extensive, complex, and irregular defects using three different tissue flaps from the same descending branch of the LCFA. The design of flap
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allowed the three or two independent flaps easier to inset for reconstruction of
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complex defects.
In this report, we present the results of the use of chimeric ALT perforator flaps, which enabled the development of two or three independent free tissue flaps based on the same descending branch of the LCFA. This chimeric ALT perforator flap was
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designed for extremity reconstruction, considering the size and characteristics of the soft tissue defects and the location and characteristics of the recipient sites.[12] For large defect areas, we primarily used the skin flap to cover sites containing nerves or
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vessels. For small defect areas or less important sites, we primarily used fascia flaps
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and subsequently covered the site with a split skin graft. In cases of overly large defects for which the two aforementioned flaps were insufficient or in cases of cavity or bone exposure repair, bone defects, or severe contamination, we performed the reconstruction using an additional muscle flap. Muscle tissue is highly vascular and, thus, is highly resistant to infection[1, 13, 14]. In some cases of severe injury to the extremities, deep defects may be associated with major arterial damage, leading to poor perfusion of the distal region of the limb. Flow-through flaps appear to represent 12
ACCEPTED MANUSCRIPT the best option in these situations because such flaps enable simultaneous arterial reconstruction and soft-tissue coverage[15]. The chimeric ALT perforator flap can be utilized for extremity reconstruction as a flow-through flap in which the pedicle
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bridges the vascular gaps[16]. In our study, flow-through ALT perforator flaps were designed in 9 cases. Vascular flow-through anastomosis was performed on the main trunk of the vessels to provide simultaneous arterial reconstruction and soft-tissue
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coverage of the extremity. In the majority of cases, the muscle, fascia, and skin flaps
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were generated completely independently by dissecting muscle, fascia, and skin on separate, individual perforators. In the vastus lateralis muscle, most of the large muscle branches emanating from the myocutaneous perforators run medially, laterally, and posteriorly from the descending branch, and flap harvesting can be completed via
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the standard method[17]. In some cases, the main pedicle associated with the fascia flap originated from the perforators of the skin flap and did not directly originate from the descending branch of the LCFA. In some cases, there were many tiny perforators
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that could not be freely dissected with the fascia flap; in these cases, a pedicle that
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was 2 to 3 cm wide was preserved to ensure the circulation of the flap. In the latter two types of flaps, a similar freedom of rotation could still be achieved when the skin and muscle islands were isolated on an individual perforator. Before surgery, we routinely performed assessment via hand-held Doppler flowmetry to reduce the uncertainty caused by variations in the vascular anatomy. The authors with the most experience in this procedure recommended this procedure[18, 19]. The localization and course of the perforators could be determined accurately, and vascular anomalies 13
ACCEPTED MANUSCRIPT could be identified[20]. During surgery, all of the perforators from the descending branch of the LCFA should be identified and preserved. We suggest that these complex chimeric flaps are ideally dissected from the pedicle to the various tissue
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components of the chimeric flap. The initial dissection of the vascular pedicle facilitates the identification of any vascular anomalies and the assessment of the quantity and quality of the perforators while the extirpative surgeon is completing the
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resection[21].
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This type of chimeric ALT perforator flaps provides several benefits. First, a minimal area of skin is harvested at the donor site to provide the largest amount of tissue possible for the coverage of a massive soft tissue defect with minimal loss of function and good cosmetic acceptability at the donor site. Second, the various
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paddles can be inset with many degrees of freedom, facilitating the coverage of complex and extensive three-dimensional defects in the extremities. Third, the various tissue components can be used for the reconstruction of complex extremity defects
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that include multiple tissue structural requirements. Finally, this flap can be designed
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with minimal effort and operation time as well as one pair of recipient vessels[22]. A disadvantage of the chimeric ALT perforator flap technique is that it requires advanced skill. The course of the perforators can be unpredictable, and small or long perforators can be difficult to harvest and inset. The microsurgeon must have superior microsurgical skills and must be familiar with perforator flaps and intramuscular perforator dissection[23]. Finally, for such extensive and complex soft tissue defects, we suggest a two-team surgery, during which the teams performing resection and 14
ACCEPTED MANUSCRIPT reconstruction operate in parallel to reduce the operation time. Our study is subject to the limitations inherent in retrospective, uncontrolled case reviews, including a small sample size, no strict criteria for patient selection, and no
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prospective data collection, especially a final strict functional assessment. 5. Conlusions
In summary, the chimeric ALT perforator flap, which is a novel variation of the
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standard ALT flap design, was found to provide large tissue components that are
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versatile and valuable. This technique facilitates the harvest of various tissue components with maximal freedom, providing maximal flexibility to meet specific reconstructive requirements for large, complex, and irregular soft-tissue defects in the extremities.
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Ethical approval
All studies have been approved by both the First Affiliated Hospital of Sun Yat-sen University and Xian Fengcheng Hospital Ethics Committee and performed in
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accordance with the ethical standards.
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Financial support None.
Author contribution
Canbin Zheng participated in the design of the operation and study, and drafted
the manuscript. Xiaoju Zheng carried out the operation, together with Canbin Zheng and helped to draft the manuscript. Baoshan Wang took charge of collecting the patients’ data and helped to perform the operation. Yongfeng Qiu took charge of 15
ACCEPTED MANUSCRIPT recruiting patients and helped to design the study. Zhong Zhang and Haijun Li followed up all the patients and analyzed the data. Xinhong Wang collected important background information. All authors read and approved the final manuscript.
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Conflicts of interest None Guarantor
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Canbin Zheng
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Acknowledgements
This work was supported by grants from National Natural Science Foundation of China (No.81401804), Science and Technology Planning Project of Guangdong Province, China (2014A020215008), Medical Scientific Research Foundation of
References
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Guangdong Province (No. B2014119).
[1] M.J. Kang, C.H. Chung, Y.J. Chang, K.H. Kim, Reconstruction of the lower
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extremity using free flaps, Arch Plast Surg 40 (2013) 575-583.
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[2] Y.G. Song, G.Z. Chen, Y.L. Song, The free thigh flap: a new free flap concept based on the septocutaneous artery, Br J Plast Surg 37 (1984) 149-159.
[3] Y.R. Kuo, J. Seng-Feng, F.M. Kuo, Y.T. Liu, P.W. Lai, Versatility of the free anterolateral thigh flap for reconstruction of soft-tissue defects: review of 140
cases, Ann Plast Surg 48 (2002) 161-166. [4] T. Agostini, D. Lazzeri, G. Spinelli, Anterolateral thigh flap: systematic literature review of specific donor-site complications and their management, J 16
ACCEPTED MANUSCRIPT Craniomaxillofac Surg 41 (2013) 15-21. [5] F. Peng, L. Chen, D. Han, C. Xiao, Q. Bao, T. Wang, Reconstruction of two separate defects in the upper extremity using anterolateral thigh chimeric flap,
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Microsurgery 33 (2013) 631-637. [6] C.Y. Kim, Y.H. Kim, Supermicrosurgical reconstruction of large defects on ischemic extremities using
supercharging techniques on latissimus dorsi
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perforator flaps, Plastic and Reconstructive Surgery 130 (2012) 135-144.
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[7] D. Izadi, J.T. Paget, M. Haj-Basheer, U.M. Khan, Fasciocutaneous flaps of the subscapular artery axis to reconstruct large extremity defects, J Plast Reconstr Aesthet Surg 65 (2012) 1357-1362.
[8] D.W. Dorfman, L.L. Pu, Using the Descending Branch of the Lateral Circumflex Recipient Vessel for Free Tissue Transfer to the
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Femoral Artery and Vein as
Difficult Areas of the Lower Extremity, Ann Plast Surg 70 (2013) 397-400. [9] P. Yu, J. Selber, Perforator patterns of the anteromedial thigh flap, Plastic and
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Reconstructive Surgery 128 (2011) 151e-157e.
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[10] E.K. Chou, B. Ulusal, A. Ulusal, F.C. Wei, C.H. Lin, C.K. Tsao, Using the descending branch of the lateral femoral circumflex vessel as a source
of two
independent flaps, Plastic and Reconstructive Surgery 117 (2006) 2059-2063.
[11] C. Jiang, F. Guo, N. Li, P. Huang, X. Jian, K. Munnee, Tripaddled anterolateral thigh flap for simultaneous reconstruction of bilateral
buccal defects after buccal
cancer ablation and severe oral submucous fibrosis release: A case report, Microsurgery 33 (2013) 667-671. 17
ACCEPTED MANUSCRIPT [12] T.A. El-Gammal, A. El-Sayed, M.M. Kotb, W.R. Saleh, Y.F. Ragheb, O. El-Refai, F.M. El, Dorsal foot resurfacing using free anterolateral thigh (ALT) flap in children, Microsurgery 33 (2013) 259-264.
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[13] H. Engel, C.H. Lin, F.C. Wei, Role of microsurgery in lower extremity reconstruction, Plastic and Reconstructive Surgery 127 Suppl 1 (2011) 228S-238S.
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[14] J.H. Lee, D.W. Chung, C.S. Han, Outcomes of anterolateral thigh-free flaps and
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conversion from external to internal fixation with bone grafting in gustilo type IIIB open tibial fractures, Microsurgery 32 (2012) 431-437. [15] J. Bullocks, B. Naik, E. Lee, L.J. Hollier, Flow-through flaps: a review of current knowledge and a novel classification system, Microsurgery 26 (2006) 439-449.
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[16] K. Sananpanich, Y.K. Tu, J. Kraisarin, P. Chalidapong, Flow-through anterolateral thigh flap for simultaneous soft tissue and long vascular gap reconstruction in extremity injuries: anatomical study and case report,
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Injury-International Journal of the Care of the Injured 39 Suppl 4 (2008) 47-54.
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[17] C.H. Wong, F.C. Wei, B. Fu, Y.A. Chen, J.Y. Lin, Alternative vascular pedicle of the anterolateral thigh flap: the oblique branch
of the lateral circumflex
femoral artery, Plastic and Reconstructive Surgery 123 (2009) 571-577.
[18] R.J. Shaw, M.D. Batstone, T.K. Blackburn, J.S. Brown, Preoperative Doppler assessment of perforator anatomy in the anterolateral thigh
flap, Br J Oral
Maxillofac Surg 48 (2010) 419-422. [19] G.G. Hallock, A primer of schematics to facilitate the design of the preferred 18
ACCEPTED MANUSCRIPT muscle perforator flaps, Plastic and Reconstructive Surgery 123 (2009) 1107-1115. [20] P. Golusinski, L. Luczewski, J. Pazdrowski, T. Synowiec, P. Pienkowski, P.
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Checinski, J. Sokalski, W. Golusinski, The role of colour duplex sonography in preoperative perforator mapping of the anterolateral thigh flap, Eur Arch Otorhinolaryngol 271 (2014) 1241-1247.
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[21] Z. Lan, Y. Shao, Z. Gu, Y. Hu, H. Li, Harvesting the lateral femoral circumflex
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chimera free flap: guidelines for elevation, Plastic and Reconstructive Surgery 131 (2013) 446-447.
[22] W.C. Huang, H.C. Chen, F.C. Wei, M.H. Cheng, D.P. Schnur, Chimeric flap in clinical use, Clinics in Plastic Surgery 30 (2003) 457-467.
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[23] T. Numajiri, Y. Sowa, K. Nishino, K. Sugimoto, Y. Iwashina, K. Ikebuchi, H. Nakano, T. Shimada, Y. Hisa, Successful retrograde arterial inflow through a muscular branch in a free anterolateral thigh chimeric flap transfer, Microsurgery
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32 (2012) 318-321.
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ACCEPTED MANUSCRIPT Figure Legends Fig. 1. (A) Perforators in the muscle, fascia, and skin from the descending branch of the LCFA. Three strategies were used to dissect the fascia flap. (B) Type I: the
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harvested free chimeric ALT perforator flap, consisting of skin, fascia, and muscle flaps, was associated with independent perforators from the descending branch of the LCFA. (C) Type II: the vascular pedicle of the fascia flap was a separate branch from
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the source vessel or was located on a side branch of the skin flap. (D) Type III: many
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tiny perforators could not be freely dissected with the fascia flap, so a 2- to 3-cm-wide fascial pedicle was preserved during harvesting.
Fig. 2. A 20-year-old man experienced an open dislocation of the ankle joint caused by a traffic accident. (A, B) Intraoperative view showing a 43 × 35 cm circular soft
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tissue defect. (C) Intraoperative view of the chimeric free ALT flap. (D, E) Intraoperative photographs revealing the different components that were placed in situ. (F) The well-healed wound at the 3-month follow-up.
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Fig. 3. A 20-year-old man sustained an incompletely severed right ankle with a large
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soft tissue defect as a result of a traffic accident. (A, B) Intraoperative imaging demonstrated a massive soft tissue defect with incomplete severing of the ankle. (C) A free chimeric ALT perforator flap was harvested to provide soft tissue coverage. (D, E) Intraoperative view after final anterolateral thigh flap insetting. Repositioning of the defatted glabrous skin as a full-sheet skin graft. (F) A satisfactory result was demonstrated at the 10-month follow-up.
20
ACCEPTED MANUSCRIPT Table 1. Patient data
20/M 2
34/M 3
20/M 4
20/M
8 9 10
11 12 13 14
16
17 18
Lower leg
18 × 12
None
Complete
Lower leg
36 × 28
Lower leg
43 × 35
Lower leg
30 × 24
25/M Crush injury
Foot
16/M Crush injury 57/M Crush injury 38/M Crush injury Motor 37/M vehicle accident 37/M Crush injury 23/M Crush injury 21/M Crush injury
45/M Crush injury
15
Flap survival
35/M Crush injury
34 × 18
Dorsum: 7 × 6 Palm：7.5×6 Distal forearm Palm: 10 × 5 + hand Dorsum: 9 × 4 Palm: 12 × 8 Hand Dorsum: 10 × 5 Distal forearm 20 × 28
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7
Comorbidi ty
Lower leg
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6
Soft-tissue defect (cm2)
17/M Crush injury
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5
Motor vehicle accident Motor vehicle accident Motor vehicle accident Motor vehicle accident
Wound location
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1
Etiology
Distal forearm
30 × 25
Distal forearm
15 × 25 Palm: 9 × 5 Hand Dorsum: 7 × 6 Distal forearm Palm: 14 × 8 + hand Dorsum: 8 × 6 Palm: 16 × 10 Wrist + hand Dorsum: 16 × 10 Palm: 18 × 9 Hand Dorsum: 8 × 5
Motor 52/M vehicle accident
Ankle + foot
20/M Crush injury
Foot
40/M Crush injury
Ankle + foot
None
Complete
None
Complete
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Age/se x
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Case no.
Dorsum: 12 × 8 Pelma：11 × 7 Dorsum: 10 × 8 Pelma：8 × 6 Dorsum: 6 × 6
None
Complete
None
Partial skin graft loss
None
Complete
None
Complete
None
Complete
None
Complete
None
Partial skin graft loss
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
None
Complete
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17 /F Crush injury
Wrist + hand
Distal forearm
None
Complete
None
Complete
Dorsum: 12×10 Palm: 12×8
Hyperten sion
Complete
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Motor 54/M vehicle accident M, male; F, female
Palm: 9 × 8 Wrist: 6 × 4 Dorsum: 15 × 8 Palm: 8 × 7
Complete
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Wrist + hand
Dorsum: 6 × 5 Pelma：30 × 12 None
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22
42/M Crush injury
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21
Ankle + foot
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20
Motor 42/M vehicle accident
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ACCEPTED MANUSCRIPT Table 2 Flap type, recipient site, and complication Complication Flap survival
14 5 3
14 5 3
2 0 0
10 12
10 12
1 1
Partial skin Venous thrombosis graft loss 1 0 0
1 0
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Flap type Type I Type II Type III Recipient site Lower extremity Upper extremity
No. of patients
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Flap type or recipient site
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ACCEPTED MANUSCRIPT Highlights: 1.
Clinical reports have described successful use of the chimeric ALT perforator flap for reconstruction of complex soft-tissue defects in the extremities. This technique facilitates the harvest of various tissue components with maximal
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2.
freedom, providing maximal flexibility to meet specific reconstructive requirements for large, complex, and irregular soft-tissue defects in the
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three types of dissection.
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The chimeric ALT perforator flap could be harvested by performing one of the
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3.
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extremities.
