Use of Ultrasound Debridement as an Adjunctive Tool for Treating Infected Prosthetic Vascular Grafts in the Lower Extremities Michele Carmo,1 Daniela Mazzaccaro,1 Iacopo Barbetta,1 Alberto M. Settembrini,1 Sergio Roveri,1 Miriam Fumagalli,1 Luca Tassinari,1 and Piergiorgio G. Settembrini,1,2 Milan, Italy

Background: To evaluate the role of an ultrasound (US) debridement system to treat conservatively patients with poor medical conditions who presented with infection of a prosthetic vascular graft in the lower extremities. Methods: Data of all patients who underwent debridement of the grafts and/or surrounding tissue using an ultrasonic generator (Genera, Italia Medica, Milan, Italy) were recorded and retrospectively reviewed. Based on cultures, patients received specific antibiotic therapy. Partial graft removal, sartorius muscle flap rotation, or negative pressure wound treatment (NPWT) was selectively used. Early and late morbidity and mortality and recurrence were analyzed. Results: Thirteen patients (median age, 72 years; range, 57e92 years; 8 men) were treated (12 Szilagyi grade III and 1 grade II infections) with US debridement without removing the graft (8 cases) or with partial excision and ‘‘in situ’’ reconstruction with a silver prosthetic graft (5 cases). Sartorius flap rotation was associated in 6 and NPWT in 1 case. One patient died perioperatively because of pulmonary edema because of sepsis secondary to treatment failure. Estimated freedom from reinfection was 90.9 ± 9% at 6 months and 77.9 ± 14% at 1 and 2 years. Estimated limb survival was 78.7 ± 13% at 6 months, 65.6 ± 16% at 1 year, and 52.5 ± 18% at 2 years. Conclusions: US debridement proved to be a valuable aid in the treatment of patients with infected grafts and poor medical conditions. Used in conjunction with antibiotics, it allowed us to be more conservative without compromising the chance of success.

INTRODUCTION Extracavitary vascular graft infection is associated with low rates of patients’ survival and poor limb salvage. However, traditional treatment with graft removal and reconstruction with autogenous or

1 Division of Vascular Surgery, S. Carlo Borromeo Hospital, Milan, Italy. 2

Chair of Vascular Surgery, Universita di Milano, Milan, Italy.

Correspondence to: Alberto M. Settembrini, MD, Divisione di Chirurgia Vascolare, Ospedale S.Carlo Borromeo, Via Pio II, Milano 3 20153, Italy; E-mail: [email protected] Ann Vasc Surg 2015; 29: 607–615 http://dx.doi.org/10.1016/j.avsg.2014.11.001 Ó 2015 Elsevier Inc. All rights reserved. Manuscript received: July 30, 2014; manuscript accepted: November 10, 2014; published online: November 26, 2014.

extra-anatomic grafts is burdened by high morbidity and mortality rates. Therefore, different surgical techniques, allowing partial graft excision, have been used especially in high-risk patients with encouraging results. Ultrasound (US) technology and its interaction with living tissues have been widely studied: the largest experience is in dentistry for cleaning purpose.1 In the 90s USs were used for decalcifying the aortic valve during conservative valve surgery. However, long-term results were disappointing because of the retraction of the cusps damaged by the energy applied.2,3 Promising results have been obtained in wound care and in diabetic foot treatment: in this field their use has spread widely even if evidences on their usefulness are still lacking.4,5 607

608 Carmo et al.

Fig. 1. Powerful ultrasonic generator (Genera).

Aim of our study was to evaluate mortality, limb survival, and freedom from reinfection after using an US debridement system, in addition to antibiotic therapy, to treat infected prosthetic grafts or dehiscence of an infected wound with an underlying vascular prosthetic graft in the lower extremities. Our goal was to achieve the best tissue and/or graft debridement to minimize the invasiveness of surgery in patients with poor medical conditions.

MATERIALS AND METHODS Device Characteristics The debriding procedure was performed using a powerful ultrasonic generator (Genera; Italia Medica, Milan, Italy; Fig. 1). This equipment operates activating a probe mounted on a piezoelectric transducer. The probe vibrates at 26 KHz with a vibratory amplitude of 15e30 mm and it is irrigated with normal saline. Different tips, assembled on the probe, have allowed its employment in many kinds of wounds and in diabetic foot management because of the specific effect associated to the shape of each tip: removing of necrotic tissue strongly adherent to a regular wound bed, reduction of bacterial charge, debridement of irregular wound, and/ or removal of small residual bones in diabetic foot. During debridement, ultrasonic waves at this frequency act on biologic tissues mainly by 2 specific nonthermal mechanisms: cavitation and acoustic streaming. Cavitation is a probe-generated, mechanical, vibratory energy that allows removal of necrotic material from wound bed. Once the US energy is applied to the tissue, microbubbles form at specific locations called nucleation sites (the mechanism of

Annals of Vascular Surgery

formation and site of these locations is not clarified in biologic tissues).6 Under this pressure, the bubbles oscillate and if they are exposed to a sufficiently high energy they collapse. This cavitation collapse of microbubbles of gas inside the tissue fluids and/or the liquid used for acoustic coupling is responsible for mechanical debridement: necrotic and infected tissues have a lower tensile strength compared with healthy and granulation tissue, allowing the former to be loosen and fragmented and the latter to be preserved.7 Moreover, microbubble cavitation induces an increase in cell membrane permeability with a reported ‘‘in vitro’’ direct bactericidal effect: this latter effect is still debated. As a matter of fact, the whole cell exposed to the US energy increases its whole activity, favoring the diffusion through the cell membrane, which is upregulated. It is possible that a better penetration of the antibiotic inside the cells plays a significant role in the bactericidal effect. Acoustic streaming is another nonthermal effect of US consisting of unidirectional, steady direct current in the acoustic field. It is determined by the difference in velocity among the different parts of the field because of the viscosity of the fluid. This flow produces a significant shear stress on cell located at the boundary of the US field, which ultimately can cause cell disruption.6 The graft and the surrounding tissues were treated with the device by moving the probe over the surface until all necrotic parts and fibrin were removed and the color of the tissue returned to appear macroscopically normal on surgeon’s inspection. We also operated the probe directly onto the graft; for Dacron grafts, we noticed no harm even when an intensive and prolonged debridement was done. Polytetrafluorethylene (PTFE) grafts need special care because when the prosthesis was treated for too long, a slight loss of impermeability was noticed. However, no major damage occurred to our grafts (Fig. 2). Patients and Methods Ethical approval was obtained from the local committee. In our study, we identified patients who presented with infection of an extracavitary vascular prosthetic graft or dehiscence of an infected wound with an underlying vascular prosthetic graft in the lower limbs (see Table I). The cohort has been chosen identifying those patients in whom a conventional approach for graft infection (complete removal of the prosthetic material and in situ revascularization with autogenous graft/homograft or ex

Vol. 29, No. 3, April 2015

Ultrasounds for vascular graft infections in the lower extremities 609

Fig. 2. Progression of prosthesis cleaning. (A) Wound dehiscence, the prosthesis is visible. (B) The prosthesis exposed before cleaning. (C) Operating the Genera

(note the change of color of the prosthesis). (D) Sartorius flap rotation; the whole wound is irrigated with rifampin.

Table I. Selection criteria for conservative treatment

Table II. Additional treatment

 Infection of an extracavitary graft or extracavitary portion of a graft  Graft patency  Poor clinical conditions (American Society of Anesthesiologists 4) or unavailable autogenous graft  No clinical suspicion of sepsis

situ with synthetic graft) was not possible, either due to poor medical conditions (American Society of Anesthesiologists 4) and/or the lack of an available autogenous graft. In all these patients, instead of a complete graft removal, we performed a partial graft removal or no removal plus an intensive US debridment of the graft, surrounding tissue, and wound. A sartorius muscle flap rotation or negative pressure wound treatment (NPWT) was adjuncted to the procedure whenever deemed helpful to treat the case (Table II). None of the patients presented clinical signs of sepsis. Patients were considered not suitable for conservative treatment if they had a Pseudomonas aeruginosaedocumented infection. All patients underwent an accurate debridement of the grafts and/or surrounding tissue, as described before. It is our policy that, if the wound is

 Repeated surgical debridment  Selective rotational muscle flap  Selective NPWT

considered clean and the edges of the wound viable, we always try a primary closure. A drain was placed in all cases and removed on the first postoperative day if empty. All patients received antibiogramguided antimicrobial therapy, when available, for at least 1 month. No additional antiseptic or antibiotic agent was used for the irrigation of the intraoperative field. Medical records were reviewed for patient demographics (sex, age, and comorbidities), clinical presentation, clinical and microbiologic features of the infection site, and operative data. Patients were followed-up at discharge at 1 and 3 months and thereafter every six months through clinical examination and US imaging. Early and late morbidity and mortality were also recorded. Late follow-up data were obtained from medical records, correspondence with referring physicians, and telephone interviews. Survival, freedom from recurrency, and limb salvage rates were estimated by the method of KaplaneMeier. Data are presented as median and

610 Carmo et al.

Annals of Vascular Surgery

Table III. Details of our case series N

Sex

Age

Infected graft

Site

Presentation

1

F

79

Composite veinDacron fem-pop AK bypass

Distal thigh

Hemorrhage

2

F

78

Dacron axillary-SFA bypass

Proximal thigh and abdomen

3

M

92

PTFE fem-pop AK bypass

4

M

62

5

M

78

6

F

67

7

M

8

Bunt szilagyi

Timing

Predictors

P1 III

Early 8 days

Multiple reinterventions, Hematoma

Abscess

P1 III

Early 15 days

Multiple reinterventions

Groin

Fistula

P1 III

Late 5 years

DM, COPD

Dacron ilio-femoral bypass + PTFE fem-pop AK bypass Composite DacronPTFE fem-pop AK bypass Dacron axillaryfemoral bypass

Groin

Infected Hematoma

P2 III

Early 12 days

Reintervention, infected hematoma

Groin

Wound dehiscence

P1 II

Late 9 months

DM, Multiple reinterventions

Groin

Wound dehiscence

P1 III

Early 15 days

67

Dacron axillarybifemoral bypass

Groin

Wound dehiscence

P1 III

Early 10 days

Infected leg ulcers, malnutrition, recent cardiac ICU admission Reintervention, Morbid obesity, COPD

M

57

RT Groin

Wound dehiscence

P2 III

Early 20 days

Multiple reinterventions, S/P aorto-enteric fistula

9

F

66

Silver Dacron aortoRT iliaceLT femoral bypass + Silver Dacron RT ilio-femoral bypass Biological bovine pericardium patch on CFA

Groin

Wound dehiscence

P3 III

Early 15 days

CRF, DM

10

M

66

Distal thigh

Abscess fistulizzation

P1 III

Early 15 days

Multiple reinterventions

11

F

82

Dacron fem-pop AK bypass + PTFE graft AK-BK Dacron cross over fem-fem bypass

Groin and pubis

Hematoma and fistula

P2 III

Late 2 years

CRF, DM

12

M

76

PTFE fem-pop AK bypass

Distal Thigh

Wound dehiscence

P2 III

Early 2 weeks

Multiple reinterventions, DM

13

M

72

Dacron ABF graft + Dacron LT femoral graft

LT Groin

Recurrent pseudoaneurysm

P2 III

Late 3 years

Multiple reinterventions, CRF

F, female; AK, above knee; SFA, superficial femoral artery; M, male; fem-pop, femoropopliteal; DM, diabetes mellitus; COPD, chronic obstructive pulmonary disease; BK, below knee; ICU, intensive care unit; RT, right; LT, left; CFA, common femoral artery; CRF, chronic renal failure.

Vol. 29, No. 3, April 2015

Ultrasounds for vascular graft infections in the lower extremities 611

Antimicrobic drugs

Microbiology

Surgical treatment

Staph. Epidermidis, Proteus Mirabilis

Partial graft excision, US debridement, Silver Dacron bypass

Teicoplanin

Staph. Epidermidis

Partial graft excision, US debridement, Silver Dacron bypass Graft excision, US debridement, Silver Dacron fem-pop bypass US debridement, Sartorius flap rotation US debridement

Levofloxacin Imipenem Teicoplanin

Staph. Aureus

Staph. Epidermidis, Eterococcus spp. Staph. Epidermidis, Eterococcus spp.

Infection outcome Late recurrence, conservatively treated with antibiotical irrigation Healed

Graft patency limb salvage

Outcome

Patent

Died for cancer at 2 years

Reintervention at 24 months

Alive at 4 years

Died for unrelated cause at 3 years Alive at 4 years

Teicoplanin

Healed

Patent

Ceftazidime Teicoplanin

Healed

Teicoplanin Amoxicillin

Healed

Thrombosis, BK amputation at 13 months Thrombosis, AK amputation at 5 months Graft patent, BK amputation

Alive at 4 years

E. Coli

US debridement, Sartorius flap rotation

Piperacillintazobactam

Healed

Aspergillus Flavus, Aspergillus Fumigatus

US debridement, Sartorius flap rotation

Voriconazole Itraconazole

Healed

Patent

Candida Glabrata, Candida Albicans, E. Coli

US debridement, Sartorius flap rotaton

Capsofungin Meropenem Metronidazole Fluconazole

Healed

BK amputation at 8 months (unrelated to infection), graft thrombosis at 14 months

Klebsiella Oxytoca, Enterob. Cloacae, Enterococcus spp Morganella M.

US debridement, Sartorius flap rotation

Imipenem

Treatment Failure: sepsis

Staph. Aureus

US debridement

Imipenem Daptomicine

Healed

Negative

Graft excision, US debridement, Silver Dacron fem-fem bypass US debridement, Sartorius flap rotation

Imipenem

Healed

Teicoplanin

Healed

Thrombosis and AK amputation at 2 years

Alive at 4 years

Imipenem

Healed

Patent

Died for unrelated cause at 4 years

MRSA, Enterococcus spp, Corynebacterium spp Corynebacterium spp

Partial graft excision, US debridement, NPWT

Thrombectomy + stenting at 2 years Patent

Lost at follow-up

Died for acute pulmonary failure at 4 years Died for unrelated cause at 3 years Died on 4th postop day for pulmonary oedema Alive at 5 years Alive at 2 years

612 Carmo et al.

IQR values or mean ± standard deviation, as appropriate.

RESULTS Thirteen patients (median age, 72 years; range, 57e 92 years) diagnosed with a prosthetic vascular graft infection or wound infection and dehiscence with an underlying vascular graft were treated conservatively in our division (see Table III for details). Eight patients were male. All of them received an extensive US debridement to allow the lower invasive reconstruction to be performed (i.e., in situ versus extra-anatomic). Conservative treatment was attempted in 8 entirely extracavitary grafts (grade P1 of Bunt classification), 4 aortic grafts with infection limited to their extracavitary portion and no clinical and radiologic signs of cavitary infection (grade P2), and 1 infected bovine pericardium patch (grade P3). In 9 cases, infection had an early onset, defined as onset within 4 months from surgical procedure, whereas the remaining 4 cases had a late presentation. In 12 cases, the infectious process was classified as grade III according to Szilagyi definition, the remaining patients were defined as grade II. Nine patients had undergone multiple operations in the infected site, whereas in 5 cases, a single previous procedure had been performed. An emergent procedure had been performed before the infection occurred in 7 of 13 patients (53%). Several systemic patient-related risk factors were recorded: diabetes mellitus in 5 patients, malnutrition and chronic renal failure in 3 patients, chronic obstructive pulmonary disease in 3 patients, whereas cancer, cirrhosis, morbid obesity, and aortoenteric fistula accounted for 1 case each. Five patients presented with a wound dehiscence, whereas a cutaneous fistula of an underlying abscess was noted in another 5. In 2 cases, the clinical presentation was an infected hematoma without fistulization. Only 1 patient presented with acute hemorrhage. Seven Dacron prostheses were involved; in 2, graft material was PTFE. A composite Dacrone PTFE or Dacronevein graft was present in 2 and 1 cases, respectively (all with a history of multiple revisions). The remaining patient suffered a bovine pericardium patch infection. In 5 cases, the graft was excised partially and a US debridement was performed to prepare the site for ‘‘in situ’’ reconstruction. All these patients received an intervascular silver prosthetic graft (Maquet, Germany). In the

Annals of Vascular Surgery

remaining 8 cases, the sole US debridement was applied to the wound and the graft, without removing the latter. We associated a sartorius flap rotation for graft coverage in 6 patients and NPWT in 1 case. Cultures were positive in all patients but one. Six patients had a single pathogen growth, whereas in the remaining 6 infection had a polymicrobial etiology. Two patients suffered from mycotic infection (Aspergillus flavus and fumigatus in one and in the other Candida albicans and glabrata, together with other microbes). Only 1 case involved methicillinresistant Staphylococcus aureus (MRSA). No involvement of Vancomycin-resistant Enterococcus (VRE) was found (see Table III for details). All patients were started on an empiric large spectrum antibiotic therapy at admission (imipenem), and they were switched to an antibiogram-guided antimicrobial therapy as cultures became available. Usually, patients are discharged with an oral antibiotic to be continued up to 3 months, according to the specific features of the clinical case (rifampin or trimethoprim + sulfamethoxazole). None of the patients died during the procedure. One patient died on the fourth postoperative day because of pulmonary edema. This patient had a treatment failure and developed sepsis (case 9). Another patient (case 1) suffered a late recurrence, which was treated conservatively by antibiotic irrigation. Four patients underwent 3 below the knee and 1 above the knee amputation during follow-up. Bypass thrombosis was the cause for 2 amputations (at 13 and 14 months after operation); no recurrent infection was noticed for both patients. In the remaining 2 cases, the amputation was performed (despite a functioning vascular reconstruction) because of ischemic lesions developed before the graft was placed. The first patient was operated after 15 days; the second had a very complicated postoperative course and considering that his lesions on the leg evolved into a dry gangrene, remaining otherwise painless and without signs of infection, amputation was postponed after 5 months. Estimated freedom from recurrent infection was 90.9 ± 9% at 6 months and 77.9 ± 14% at 1 and 2 years. Estimated limb survival was 78.7 ± 13% at 6 months, 65.6 ± 16% at 1 year, and 52.5 ± 18% at 2 years.

DISCUSSION Prosthetic graft infection remains one of the most frightening complications in vascular surgery. For this reason, treatment should be aggressive: graft

Vol. 29, No. 3, April 2015

Ultrasounds for vascular graft infections in the lower extremities 613

removal, with an extensive debridement of the surgical site, followed by ex situ bypass and a prolonged antibiotic therapy are altogether traditionally used. More recently, several authors have made attempts to decrease the invasiveness of surgery by approaching these patients more conservatively. Extracavitary infections, less aggressive (gram positive) and possibly single pathogen, early onset, and partial graft involvement are the suggested inclusive criteria to appropriately select the candidates for this type of surgery. However, infections more often affect older patients with poor medical conditions and/or multiple comorbidities, a portion of the general population whose prevalence is rapidly increasing, these patients are often too fragile to allow a radical surgical treatment. Different techniques have been used in such cases. Partial removal of the infected portion has claimed to be as effective as a radical excision of the graft, both Calligaro in 20038 and Hart in 20059 reported that even in case of bifurcated aortic graft infections, complete graft excision is not always necessary and, in prohibitive risk patients, partial or no removal of infected segments associated with optimal antimicrobial therapy led to comparable short- and long-term outcomes in terms of mortality and recurrence of the infection. Supported by these data, in our series we attempted partial or no graft removal, associated with optimal systemic antimicrobial therapy and local debridement with or without tissue coverage. In the light of the various options of conservative treatment, surgical wound debridement (WD) and muscle transposition flap coverage have obtained encouraging low amputation rates.10 In our series, muscle flap rotation was used only when healthy tissue was not sufficient to completely cover the exposed graft; solely in 1 of 6 cases we observed a local recurrence after flap coverage. Surgical WD followed by NPWT with the vacuum-assisted closure device (V.A.C.Ò; KCI) has been more recently introduced, and this is an appealing alternative to major vascular reconstruction with the purpose of wound healing and graft preservation.11 The largest experience reporting on NPWT in treating vascular graft infection comes from India, where Tripathi used this device after accurate WD, sartorius flap, partial graft removal with vein graft replacement in 68 patients with 72 groin Szilagyi grade III infections. Fifty-five of them were prosthetic bypass. Among these, 48 cases (87.3%) were preserved without needing a revision. Mean duration of the therapy was 16 ± 7.7 days. Only 1 patient died because of bleeding complications. In our series, NPWT was used only in 1

patient: in fact, most of the infections occurred before the NPWT devices became available. Moreover, this low use of the VAC device is likely because of our strategy, which is to close primarily the skin above the graft whenever we can obtain a satisfactory cleaning of the wound and the skin tissue allows a tension free suture, therefore, limiting the use of NPWT. Berger et al.12 reported their experience on 17 Szilagyi grade III groins, using double sponge (white foam and granu foam) Vacuum therapy directly on exposed Dacron or PTFE graft and low topical negative pressure (50 mm Hg) to promote periarterial granulation, with good results. Fourteen (82%) had a complete wound closure, no wound or anastomotic bleeding, but long time of healing (mean length of stay in hospital was 21 days and mean time for complete healing 51 days). US as a therapeutic agent in chronic wound healing has been extensively studied in the literature.13 However, its use in vascular graft infection has not been investigated yet. Indeed, how US can improve wound healing is still unclear, as there is a lack of high-level evidence about the effectiveness of therapeutic ultrasonography for local and systemic wound care.14 Some mechanisms have been advocated to explain the therapeutic effects of US; when applied to the wound bed, ultrasonic energy penetrates into deep tissue, and the associated fibrinolytic action cleaves the superficial dead tissue, exudates, and other nonviable matter without removing healthy tissue. Debridement is essential for proper wound management as it enhances the proliferative phase activity allowing viable cells to provide adequate coverage. Besides, US enhancement of antibiotic action against bacterial biofilms has been reported. Biofilm infections are challenging to eradicate, probably because of the heterogeneity of involved bacterial species and the decreased penetration of antibiotics. Low frequency US (LFUS) may play an important role in increasing the penetration of antibiotics in biofilms against certain species of bacteria. Carmen et al. in 200515 reported the successful reduction of the viability of Escherichia coli biofilms implanted in 5 rabbits, which were treated for 48 hr using LFUS and gentamicin. However, the same treatment failed in another 14 rabbits when P aeruginosa was the offensive organism. Xu et al.16 recently reported the destruction of P aeruginosa biofilms on implantmimicking graphite disks after 15-sec exposure and 3 millisec pulse-period of high-intensity focused US. In 2011, He et al.17 described the enhanced effect of vancomycin combined with US-targeted

614 Carmo et al.

microbubble in destroying Staphylococcus epidermidis biofilms in rabbits. Because of cavitation, high pressure, and high shear stress, US may increase cell permeability and stimulate transport of the antibiotics through the biofilm. Second, generation of intracellular reactive oxygen species after the application of US might permeabilize the cell membrane. Experiences reporting on clinical application of US, however, are still poor. Herberger et al.18 in 2011 reported their results of a monocentric, prospective, randomized controlled clinical study to assess patient-reported outcomes and clinical efficacy of US-assisted wound (UAW) treatment, compared with surgical WD, on a total of 67 patients. They found that UAW displayed the same high efficacy, comparable patient benefit, and improved quality of life than conventional surgical debridement (88% of UAW and 85.2% of WD patients experienced more-than-minimal patient benefit). Aim of our study was to evaluate the results of this novel surgical site infection treatment in a subset of patients considered at extremely high risk for major surgery. We used this technique to achieve the best tissue and/or graft debridement for minimizing the invasiveness of surgery. In our series, ultrasonic debridement as an adjunctive next to antibiotic treatment, sartorious flap or NPWT promoted wound healing with a less invasive approach in patients with poor medical condition or unavailable autogenous graft. However, it is very hard to conclude the exact role of US debridement in the successful outcome of these patients. No harm was noted on Dacron grafts even when an intensive and prolonged debridement was done, whereas PTFE grafts need special attention, because of a potential loss of impermeability after prolonged US exposure. As for the type of bacteria, in our patients, gram positive represented the main class of organism involved in vascular surgical site infection. In 1 case only, an MRSA was isolated from the culture of the surgical site, but it was successfully eradicated using an association of imipenem and daptomicin. P aeruginosa was never isolated from cultures in our series. According to the higher failure rate reported in the literature, we usually do not attempt a conservative approach when P aeruginosa is the pathogen involved in grafts infection.19 Limitations of our study are the small number of patients and its retrospective design. Moreover, the inhomogeneity of the series accounts for multiple confounding factors, which did not allow to generalize the results obtained. Therefore, we are not able to draw conclusions or suggest

Annals of Vascular Surgery

recommendations, but in our opinion, US debridement can be a useful tool which can help facing this terrible complication.

CONCLUSIONS In this short series, we used US to perform an extensive debridement of infected prosthetic vascular grafts or infected wounds with an underlying vascular graft, in the lower extremities. This was always used in conjunction with antibiotic therapy. Sartorius flap coverage and partial graft removal were selectively performed. It is our opinion that in selected cases (fragile patients for whom a more aggressive approach is considered prohibitive) this technique might allow treating these patients more conservatively, potentially preserving their chances of success. REFERENCES 1. Stach DJ. Perspectives on ultrasonics, sonics. Their role in periodontal debridement. Dent Teamwork 1994;7:22e5. 2. Kellner HJ, Pracki P, Hildebrandt A, et al. Aortic valve debridement by ultrasonic surgical aspirator in degenerative, aortic valve stenosis: follow-up with Doppler echocardiography. Eur J Cardiothorac Surg 1996;10:498e504. 3. Baumgartner FJ, Pandya A, Omari BO, et al. Ultrasonic debridement of mitral calcification. J Card Surg 1997;12: 240e2. 4. Bell DP Jr. Diabetic foot ulcers: current treatment options and new developments. Surg Technol Int 2010;20:97e105. 5. Kim PJ, Steinberg JS. Wound care: biofilm and its impact on the latest treatment modalities for ulcerations of the diabetic foot. Semin Vasc Surg 2012;25:70e4. 6. Wu J, Nyborg WL. Ultrasound, cavitation bubbles and their interaction with cells. Adv Drug Deliv Rev 2008;60: 1103e16. 7. O’Brein WD Jr. Ultrasounddbiophysics mechanism. Prog Biophys Mol Biol 2007;93:212e55. 8. Calligaro KD, Veith FJ, Yuan JG, et al. Intra-abdominal aortic graft infection: complete or partial graft preservation in patients at very high risk. J Vasc Surg 2003;38:1199e205. 9. Hart JP, Eginton MT, Brown KR, et al. Operative strategies in aortic graft infections: is complete graft excision always necessary? Ann Vasc Surg 2005;19:134e60. 10. Reiffel AJ, Henderson PW, Karwowski JK, et al. An interdisciplinary approach to the prevention and treatment of groin wound complications after lower extremity revascularization. Ann Vasc Surg 2012;26:365e72. 11. Acosta S, Monsen C. Outcome after VAC therapy for infected bypass grafts in the lower limb. Eur J Vasc Endovasc Surg 2012;44:294e9. 12. Berger P, de Bie D, Moll F, et al. Negative pressure wound therapy on exposed prosthetic vascular grafts in the groin. J Vasc Surg 2012;56:714e20. 13. Voigt J, Wendelken M, Driver V, et al. Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: a systematic review of the literature and meta-analysis of eight randomized controlled trials. Int J Low Extrem Wounds 2011;10:190e9.

Vol. 29, No. 3, April 2015

Ultrasounds for vascular graft infections in the lower extremities 615

14. Br€ olmann FE, Ubbink DT, Nelson EA, et al. Evidence-based decisions for local and systemic wound care. Br J Surg 2012;99:1172e83. 15. Carmen JC, Roeder BL, Nelson JL, et al. Treatment of biofilm infections on implants with low-frequency ultrasound and antibiotics. Am J Infect Control 2005;33: 78e82. 16. Xu J, Bigelow TA, Halverson LJ, et al. Minimization of treatment time for in vitro 1.1 MHz destruction of Pseudomonas aeruginosa biofilms by high-intensity focused ultrasound. Ultrasonics 2012;52:668e75.

17. He N, Hu J, Liu H, et al. Enhancement of vancomycin activity against biofilms by using ultrasound-targeted microbubble destruction. Antimicrob Agents Chemother 2011;55:5331e7. 18. Herberger K, Franzke N, Blome C, et al. Efficacy, tolerability and patient benefit of ultrasound-assisted wound treatment versus surgical debridement: a randomized clinical study. Dermatology 2011;222:244e9. 19. Calligaro KD, Veith FJ, Schwartz ML, et al. Selective preservation of infected prosthetic arterial grafts: analysis of a 20year experience with 120 extracavitary infected grafts. Ann Surg 1994;220:461e71.

Use of ultrasound debridement as an adjunctive tool for treating infected prosthetic vascular grafts in the lower extremities.

To evaluate the role of an ultrasound (US) debridement system to treat conservatively patients with poor medical conditions who presented with infecti...
934KB Sizes 0 Downloads 4 Views