Childs Nerv Syst DOI 10.1007/s00381-014-2406-7
TECHNICAL NOTE
Relaxed pericranial flap for distraction osteogenesis to treat craniosynostosis: a technique for wound reinforcement—technical note Kuniaki Nakahara & Shigehiro Ikemoto & Satoru Shimizu & Masaru Yamada & Toshihiro Kumabe
Received: 13 March 2014 / Accepted: 17 March 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Although distraction osteogenesis has been widely accepted to treat craniosynostosis, it occasionally results in wound complications. Positing that they are attributable to the tense pericranium under the scalp, we developed a simple technique to relax the pericranial flap. Methods In 12- to 15-month-old infants (mean 13 months), we placed a coronal skin incision and dissected the scalp at the subgaleal layer. Then, we peeled the intact pericranium away from the skull along the planned osteotomy to obtain flaps with pedicles on the caudal part. After osteotomy and setting of the distraction device, the pericranial flaps freed from the scalp flap were repositioned to fit the osteotomy line, dura, and distraction device. The galea and skin were approximated layer by layer. Results The shape of the skull was successfully corrected, and the bone defect created by expansion was filled by osteogenesis in all patients. During a mean follow-up period of 42.2 months, we encountered no wound complications. Conclusions The replaced relaxed pericranium closely adhered to the osteotomy, and the distraction device facilitated vascular growth and bone restoration. Bone resorption was prevented and skin expansion promoted. In patients with iatrogenic dural injury, the pericranium over the injured dura serves as a barrier to prevent cerebrospinal fluid leakage.
K. Nakahara (*) : S. Shimizu : M. Yamada : T. Kumabe Department of Neurosurgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan e-mail: [email protected] S. Ikemoto Department of Plastic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
Keywords Pericranial flap . Craniosynostosis . Distraction . Osteogenesis
Introduction Distraction osteogenesis is a technique to obtain bone extension. It involves osteotomy, the placement of distraction devices that facilitate the gradual extension of bone at the osteotomy site. Osteogenesis between the osteotomy lines replaces conventional intraoperative extension and bone graft insertion. McCarthy et al. [1] first reported the use of this technique for craniomaxillofacial surgery to the mandible in 1992, and it is now widely used to treat patients with craniosynostosis. However, distraction osteogenesis occasionally results in complications such as skin infection due to fluid collection or excessive strain on the skin at the incision site and to device exposure and dislocation [2–8]. Under the hypothesis that wound complications were attributable to tense pericranium underlying the scalp (Fig. 1, left), we developed a simple technique to relax the pericranial flap.
Patients and method We treated five infants with brachycephaly by distraction osteogenesis. They ranged in the age from 12 to 15 months (mean 13 months); four were symptomatic and one presented with asymptomatic craniosynostosis (Table 1). The head of endotracheally intubated patients was placed on a horseshoe headrest. A coronal skin incision was made, and the scalp was dissected at the subgaleal layer leaving the pericranium intact (Fig. 2a). The periosteum was gently peeled away from the skull along the osteotomy design to obtain flaps with pedicles in the caudal part (Fig. 2b). Freed from the scalp, the pericranium featured extensible flaps.
Childs Nerv Syst Fig. 1 Diagram showing the role of the pericranium, a tense tissue, in wound healing after distraction osteogenesis for brachycephaly. In the conventional skin flap procedure (left panel), the pericranium is not dissected from the skin. This may hamper wound adaptation due to tension (bidirectional arrow) and may not provide a good fit to the osteotomy and the sutured dural injury. In the modified skin flap procedure (right panel), the relaxed pericranium obtained by dissection from the skin flap does not impede wound adaptation and provides a good fit to the osteotomy and the sutured dural injury. Consequently, wound reinforcement and osteogenesis promotion can be expected
Consequently, the tissue accommodated the device, the osteotomy, and any sutured dural injury. We performed a one-piece osteotomy of the frontal bone flap including the orbital rim and placed the distraction device (Fig. 2c). The pericranial flaps were repositioned to cover the osteotomy line and the distraction device (Fig. 2d). We carefully placed the pericranial flap on the osteotomy and the exposed dura. After hemostasis and the placement of a subgaleal drain, the galea and skin were approximated layer by layer using absorbable sutures; the shaft of the distraction device penetrated the skin. The wet dressing covering the wound was removed 3 days after the operation. After confirming satisfactory wound adaptation and the absence of subcutaneous cerebrospinal fluid (CSF) accumulation, skull expansion was started on the fourth postoperative day. The patients were followed for 26 to 52 months (mean 42.2 months). To evaluate the effect of the relaxed pericranial flap, we reviewed four patients who were treated before the introduction of our new method with a conventional single-layer skin flap including the periosteum.
These patients were followed for 39 to 112 months (mean 63.6 months; Table 2).
Results The shape of the skull was successfully corrected in all five patients, and the bone defect created by expansion was ultimately filled by osteogenesis. During skull expansion, we did not encounter CSF leakage, skin- or device-related complications such as wound infection or excessive scarring, or device exposure and dislocation in any of our patients. There was one incidence of local infection at the cut end of the shaft (Table 1); the scar tissue associated with the infection was removed during a second surgery for removal of the expander. To date, no patient required additional surgery for complications elicited by cranial expansion. In our earlier series, two of four patients developed skin complications (Table 2).
Discussion Table 1 Patients with brachycephaly treated by distraction osteogenesis using relaxed pericranial flaps Patient Age at operation (months) Dural injury Complication 1 2 3 4 5 a
12 12 12 14 15
At the cut end of the device shaft
Yes No No No Yes
No No No No Local skin infectiona
Since IIizarov [10] began using distraction osteogenesis for limb lengthening, the procedure has been applied to reconstruct and lengthen tubular bones. McCarthy et al. [1] first applied this technique to correct craniofacial deformities; it has also been used to repair segmental bone defects in the craniofacial bone after tumor resection and trauma. The technique initiates new bone growth without bone transplantation and promotes the growth of soft tissue. Although cranial distraction osteogenesis requires more time than conventional cranial expansion surgery before the
Childs Nerv Syst Fig. 2 Distraction osteogenesis for brachycephaly in a 14-monthold boy (case 4). a After retraction of the skin-galea flap, the design of the planned osteotomy is marked on the pericranium. b The pericranium is incised, peeled away from the skull, and the periosteum flaps are repositioned. c Coronal osteotomy of a onepiece frontal bone flap is performed, and the distraction device is settled to cross the osteotomy. d The sutured periosteum flaps cover the osteotomy and distraction devices
results become obvious, a variety of advantages have been documented. Distraction osteogenesis is less invasive than conventional surgery and involves less blood loss and a shorter operation time [3]. The postoperative complication rate, especially that of infection, has decreased, and increases in intracranial pressure have been reduced effectively. The procedure also allows the soft tissue to expand or grow gradually along with the expanding cranium. Although distraction osteogenesis is simple, safe, and useful, there have been some surgery-related minor complications. According to earlier reports, skin infection occurred in 16 % of patients, device exposure in 8.8 %, device dislocation in 6.3 %, device distortion in 1.3 %, and deformed advancement in 1.3 % [3–9]. Takeuchi et al. [11] documented that in the canine mandible, preservation of the periosteum prevented the resorption of external bone during distraction osteogenesis. Samee et al. [12] demonstrated that the periosteum contains mesenchymal
progenitor cells that differentiate into osteoblasts and suggested that bone morphogenetic protein-2 and vascular endothelial growth factor play important roles in cell-based approaches to bone regeneration. We suggest that the close adherence of the relaxed pericranium to the osteotomy and the distraction device (Fig. 1, right) promotes vascular growth, restores bone effectively, prevents bone resorption, and facilitates expansion of the skin on the device. In addition, in the presence of iatrogenic dural injury, the pericranium fits the dura well and is a barrier to prevent CSF leakage. It is evident that our new method protects the skin more effectively than the conventional single-layer skin flap including the periosteum. Additional studies in larger series are underway to confirm the applicability of the technique presented here.
References Table 2 Patients with brachycephaly treated by osteogenesis without the use of relaxed pericranial flaps Patient
Age at operation (months)
Dural injury
Complications
1 2 3 4
26 23 36 27
Yes Yes No No
Device exposure Skin infection No Dislocation of the device
1. McCarthy JG, Schreiber J, Karp N, Thorne CH, Grayson BH (1992) Lengthening the human mandible by gradual distraction. Plast Reconstr Surg 89:1–8 2. Jung A, Lee DH, Park SH, Yoon JC (2008) Distractor breakage in cranial distraction osteogenesis for children with craniosynostosis. Pediatr Neurosurg 44:216–220 3. Akai T, Iizuja H, Kawakami S (2006) Treatment of craniosynostosis by distraction osteogenesis. Pediatr Neurosurg 42:288–292 4. Akizuki T, Komuro Y, Ohmoro K (2004) Distraction osteogenesis for craniosynostosis. Neurosurg Forcus 9:1–7
Childs Nerv Syst 5. Cho BC, Hwang SK, Uhm KI (2004) Distraction osteogenesis of the cranial vault for the treatment of craniofacial synostosis. J Cranio Surg 58:135–144 6. Komuro Y, Yanai A, Hayashi A, Nakanishi H, Miyajima M, Arai H (2005) Cranial reshaping employing distraction and contraction in the treatment of sagittal synostosis. Br J Plast Surg 58:196–201 7. Morota M, Ogiwara H, Kaneko T (2012) Hybrid surgery for scaphocephaly with distraction osteogenesis using skull expanders : technical note. Childs Nerv Syst 28:1353–1358 8. Nishimoto S, Oyama T, Nagashime T, Shimizu F, Tsugawa T, Takeda M, Toda N (2006) Gradual distraction fronto-orbital advancement with ‘floating forehead’ for patients with syndromic craniosynostosis. J Craniofac Surg 17:497–505
9. Yano H, Tanaka K, Sueyoshi O, Takahashi K, Hirata R, Hirano A (2006) Cranial vault distraction: its illusionary effect and limitation. Plast Reconstr Surg 117:193–200 10. Ilizarov GA (1989) The tension-stress effect on the genesis and growth of tissues. Part 1. The influence of stability of fixation and soft tissue prevention. Clin Orthop 238:249–281 11. Takeuchi S, Matso A, Chiba H (2010) Beneficial role of periosteum in distraction osteogenesis of mandible: its preservation prevents external bone resorption. Tohoku J Exp Med 220:67–75 12. Samee M, Kasugai S, Kondo H, Ohya K, Shimokawa H, Kuroda S (2008) Bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VFGF) transfection to human periosteal cells enhances osteoblast differentiation and bone formation. J Pharmacol Sci 108:18–31
TECHNICAL NOTE
Relaxed pericranial flap for distraction osteogenesis to treat craniosynostosis: a technique for wound reinforcement—technical note Kuniaki Nakahara & Shigehiro Ikemoto & Satoru Shimizu & Masaru Yamada & Toshihiro Kumabe
Received: 13 March 2014 / Accepted: 17 March 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Although distraction osteogenesis has been widely accepted to treat craniosynostosis, it occasionally results in wound complications. Positing that they are attributable to the tense pericranium under the scalp, we developed a simple technique to relax the pericranial flap. Methods In 12- to 15-month-old infants (mean 13 months), we placed a coronal skin incision and dissected the scalp at the subgaleal layer. Then, we peeled the intact pericranium away from the skull along the planned osteotomy to obtain flaps with pedicles on the caudal part. After osteotomy and setting of the distraction device, the pericranial flaps freed from the scalp flap were repositioned to fit the osteotomy line, dura, and distraction device. The galea and skin were approximated layer by layer. Results The shape of the skull was successfully corrected, and the bone defect created by expansion was filled by osteogenesis in all patients. During a mean follow-up period of 42.2 months, we encountered no wound complications. Conclusions The replaced relaxed pericranium closely adhered to the osteotomy, and the distraction device facilitated vascular growth and bone restoration. Bone resorption was prevented and skin expansion promoted. In patients with iatrogenic dural injury, the pericranium over the injured dura serves as a barrier to prevent cerebrospinal fluid leakage.
K. Nakahara (*) : S. Shimizu : M. Yamada : T. Kumabe Department of Neurosurgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan e-mail: [email protected] S. Ikemoto Department of Plastic Surgery, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
Keywords Pericranial flap . Craniosynostosis . Distraction . Osteogenesis
Introduction Distraction osteogenesis is a technique to obtain bone extension. It involves osteotomy, the placement of distraction devices that facilitate the gradual extension of bone at the osteotomy site. Osteogenesis between the osteotomy lines replaces conventional intraoperative extension and bone graft insertion. McCarthy et al. [1] first reported the use of this technique for craniomaxillofacial surgery to the mandible in 1992, and it is now widely used to treat patients with craniosynostosis. However, distraction osteogenesis occasionally results in complications such as skin infection due to fluid collection or excessive strain on the skin at the incision site and to device exposure and dislocation [2–8]. Under the hypothesis that wound complications were attributable to tense pericranium underlying the scalp (Fig. 1, left), we developed a simple technique to relax the pericranial flap.
Patients and method We treated five infants with brachycephaly by distraction osteogenesis. They ranged in the age from 12 to 15 months (mean 13 months); four were symptomatic and one presented with asymptomatic craniosynostosis (Table 1). The head of endotracheally intubated patients was placed on a horseshoe headrest. A coronal skin incision was made, and the scalp was dissected at the subgaleal layer leaving the pericranium intact (Fig. 2a). The periosteum was gently peeled away from the skull along the osteotomy design to obtain flaps with pedicles in the caudal part (Fig. 2b). Freed from the scalp, the pericranium featured extensible flaps.
Childs Nerv Syst Fig. 1 Diagram showing the role of the pericranium, a tense tissue, in wound healing after distraction osteogenesis for brachycephaly. In the conventional skin flap procedure (left panel), the pericranium is not dissected from the skin. This may hamper wound adaptation due to tension (bidirectional arrow) and may not provide a good fit to the osteotomy and the sutured dural injury. In the modified skin flap procedure (right panel), the relaxed pericranium obtained by dissection from the skin flap does not impede wound adaptation and provides a good fit to the osteotomy and the sutured dural injury. Consequently, wound reinforcement and osteogenesis promotion can be expected
Consequently, the tissue accommodated the device, the osteotomy, and any sutured dural injury. We performed a one-piece osteotomy of the frontal bone flap including the orbital rim and placed the distraction device (Fig. 2c). The pericranial flaps were repositioned to cover the osteotomy line and the distraction device (Fig. 2d). We carefully placed the pericranial flap on the osteotomy and the exposed dura. After hemostasis and the placement of a subgaleal drain, the galea and skin were approximated layer by layer using absorbable sutures; the shaft of the distraction device penetrated the skin. The wet dressing covering the wound was removed 3 days after the operation. After confirming satisfactory wound adaptation and the absence of subcutaneous cerebrospinal fluid (CSF) accumulation, skull expansion was started on the fourth postoperative day. The patients were followed for 26 to 52 months (mean 42.2 months). To evaluate the effect of the relaxed pericranial flap, we reviewed four patients who were treated before the introduction of our new method with a conventional single-layer skin flap including the periosteum.
These patients were followed for 39 to 112 months (mean 63.6 months; Table 2).
Results The shape of the skull was successfully corrected in all five patients, and the bone defect created by expansion was ultimately filled by osteogenesis. During skull expansion, we did not encounter CSF leakage, skin- or device-related complications such as wound infection or excessive scarring, or device exposure and dislocation in any of our patients. There was one incidence of local infection at the cut end of the shaft (Table 1); the scar tissue associated with the infection was removed during a second surgery for removal of the expander. To date, no patient required additional surgery for complications elicited by cranial expansion. In our earlier series, two of four patients developed skin complications (Table 2).
Discussion Table 1 Patients with brachycephaly treated by distraction osteogenesis using relaxed pericranial flaps Patient Age at operation (months) Dural injury Complication 1 2 3 4 5 a
12 12 12 14 15
At the cut end of the device shaft
Yes No No No Yes
No No No No Local skin infectiona
Since IIizarov [10] began using distraction osteogenesis for limb lengthening, the procedure has been applied to reconstruct and lengthen tubular bones. McCarthy et al. [1] first applied this technique to correct craniofacial deformities; it has also been used to repair segmental bone defects in the craniofacial bone after tumor resection and trauma. The technique initiates new bone growth without bone transplantation and promotes the growth of soft tissue. Although cranial distraction osteogenesis requires more time than conventional cranial expansion surgery before the
Childs Nerv Syst Fig. 2 Distraction osteogenesis for brachycephaly in a 14-monthold boy (case 4). a After retraction of the skin-galea flap, the design of the planned osteotomy is marked on the pericranium. b The pericranium is incised, peeled away from the skull, and the periosteum flaps are repositioned. c Coronal osteotomy of a onepiece frontal bone flap is performed, and the distraction device is settled to cross the osteotomy. d The sutured periosteum flaps cover the osteotomy and distraction devices
results become obvious, a variety of advantages have been documented. Distraction osteogenesis is less invasive than conventional surgery and involves less blood loss and a shorter operation time [3]. The postoperative complication rate, especially that of infection, has decreased, and increases in intracranial pressure have been reduced effectively. The procedure also allows the soft tissue to expand or grow gradually along with the expanding cranium. Although distraction osteogenesis is simple, safe, and useful, there have been some surgery-related minor complications. According to earlier reports, skin infection occurred in 16 % of patients, device exposure in 8.8 %, device dislocation in 6.3 %, device distortion in 1.3 %, and deformed advancement in 1.3 % [3–9]. Takeuchi et al. [11] documented that in the canine mandible, preservation of the periosteum prevented the resorption of external bone during distraction osteogenesis. Samee et al. [12] demonstrated that the periosteum contains mesenchymal
progenitor cells that differentiate into osteoblasts and suggested that bone morphogenetic protein-2 and vascular endothelial growth factor play important roles in cell-based approaches to bone regeneration. We suggest that the close adherence of the relaxed pericranium to the osteotomy and the distraction device (Fig. 1, right) promotes vascular growth, restores bone effectively, prevents bone resorption, and facilitates expansion of the skin on the device. In addition, in the presence of iatrogenic dural injury, the pericranium fits the dura well and is a barrier to prevent CSF leakage. It is evident that our new method protects the skin more effectively than the conventional single-layer skin flap including the periosteum. Additional studies in larger series are underway to confirm the applicability of the technique presented here.
References Table 2 Patients with brachycephaly treated by osteogenesis without the use of relaxed pericranial flaps Patient
Age at operation (months)
Dural injury
Complications
1 2 3 4
26 23 36 27
Yes Yes No No
Device exposure Skin infection No Dislocation of the device
1. McCarthy JG, Schreiber J, Karp N, Thorne CH, Grayson BH (1992) Lengthening the human mandible by gradual distraction. Plast Reconstr Surg 89:1–8 2. Jung A, Lee DH, Park SH, Yoon JC (2008) Distractor breakage in cranial distraction osteogenesis for children with craniosynostosis. Pediatr Neurosurg 44:216–220 3. Akai T, Iizuja H, Kawakami S (2006) Treatment of craniosynostosis by distraction osteogenesis. Pediatr Neurosurg 42:288–292 4. Akizuki T, Komuro Y, Ohmoro K (2004) Distraction osteogenesis for craniosynostosis. Neurosurg Forcus 9:1–7
Childs Nerv Syst 5. Cho BC, Hwang SK, Uhm KI (2004) Distraction osteogenesis of the cranial vault for the treatment of craniofacial synostosis. J Cranio Surg 58:135–144 6. Komuro Y, Yanai A, Hayashi A, Nakanishi H, Miyajima M, Arai H (2005) Cranial reshaping employing distraction and contraction in the treatment of sagittal synostosis. Br J Plast Surg 58:196–201 7. Morota M, Ogiwara H, Kaneko T (2012) Hybrid surgery for scaphocephaly with distraction osteogenesis using skull expanders : technical note. Childs Nerv Syst 28:1353–1358 8. Nishimoto S, Oyama T, Nagashime T, Shimizu F, Tsugawa T, Takeda M, Toda N (2006) Gradual distraction fronto-orbital advancement with ‘floating forehead’ for patients with syndromic craniosynostosis. J Craniofac Surg 17:497–505
9. Yano H, Tanaka K, Sueyoshi O, Takahashi K, Hirata R, Hirano A (2006) Cranial vault distraction: its illusionary effect and limitation. Plast Reconstr Surg 117:193–200 10. Ilizarov GA (1989) The tension-stress effect on the genesis and growth of tissues. Part 1. The influence of stability of fixation and soft tissue prevention. Clin Orthop 238:249–281 11. Takeuchi S, Matso A, Chiba H (2010) Beneficial role of periosteum in distraction osteogenesis of mandible: its preservation prevents external bone resorption. Tohoku J Exp Med 220:67–75 12. Samee M, Kasugai S, Kondo H, Ohya K, Shimokawa H, Kuroda S (2008) Bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VFGF) transfection to human periosteal cells enhances osteoblast differentiation and bone formation. J Pharmacol Sci 108:18–31
