Surgical management of infrainguinal arterial prosthetic graft infections: review of a thirty-five-year experience

Outcomes of biosynthetic collagen prostheses with comparison to cryopreserved arterial homografts for bypass reconstruction in infrainguinal vascular graft infections

BACKGROUND AND AIMS

Managing infrainguinal vascular graft infections (VGI) in bypass reconstruction is complex. Although an autologous vein is the preferred graft material, alternative conduits are required when autologous veins are unavailable. This study aimed to compare the efficacy of cryopreserved arterial homografts and biosynthetic glutaraldehydemodifiedovine collagen grafts (Omniflow II) for the treatment of infrainguinal VGI.

METHODS

The study was retrospective across two centers and included patients with infrainguinal VGI treated with cryopreserved arterial homografts or Omniflow II grafts between 2009 and 2019. Freedom from reinfection, primary patency rates, amputation-free survival, and overall survival were analyzed using 5-year Kaplan-Meier estimates.

RESULTS

Overall, 63 patients with infrainguinal VGI were treated with either Omniflow II grafts (n = 34) or cryopreserved arterial homografts (n = 29). At 5 years, freedom from reinfection was 97.1% for Omniflow II grafts and 93.1% for cryopreserved arterial homografts (p = .4). Primary patency was 50% for Omniflow II grafts and 55.2% for the cryopreserved arterial homografts (p = .5). Amputation-free survival was 52.9% for Omniflow II grafts and 55.2% for cryopreserved arterial homografts (p = .7). No graft degeneration or graft ruptures were observed during the follow-up.

CONCLUSIONS

This study suggests that biosynthetic grafts are viable and accessible alternatives for traditional graft materials, offering similar efficacy and ease of use. Although autologous vein grafts remain the gold standard for VGI management, biosynthetic grafts may serve as a viable alternatives to cryopreserved arterial homografts in the treatment of infrainguinal VGIs.

Vascular Graft Infections Treated With Bioabsorbable Antibiotic Beads

INTRODUCTION

Inguinal vascular surgical site infections (VSSI) and infected prosthetic grafts remain a critical problem in vascular surgery. Prior clinical reports suggest antibiotic-impregnated beads may be used to attempt salvage of the graft and improve outcomes, especially if explant would result in major amputation or mortality. Described is our institutional experience managing inguinal VSSI using bioabsorbable, antibiotic-impregnated beads compared to inguinal VSSI managed with debridement alone.

METHODS

Patients with VSSIs after lower-extremity procedures were identified through the institutional database and departmental registries from 2014 to 2023. Cases were excluded if they did not involve an inguinal wound infection or an operation for VSSI management. Outcomes, including amputation-free survival, reinfection, and re-operation for infection were recorded, along with microbial isolates. Basic descriptive statistics, Kaplan-Meier, and Multiple variable Cox proportional hazards analyses were performed.

RESULTS

There were 43 patients identified (23 with intravenous antibiotics and debridement alone, and 20 treated with intravenous antibiotics, debridement, and antibiotic beads). The two groups differed significantly in their Szilagyi classification, with thirteen patients (65%) with class III infections in the antibiotic bead group compared with one (7%) in the debridement alone group. There was no significant difference in amputation-free survival for those cases that received debridement and antibiotic beads versus debridement alone (P = 0.20) or amputation-free survival between Szilagyi classifications (P = 0.47) despite a higher representation of Szilagyi III cases in the antibiotic bead group (P = 0.0001). Patients with graft infections treated with beads experienced similar survival outcomes to patients with subcutaneous infections treated with debridement alone (P = 0.21).

CONCLUSIONS

The efficacy of bioabsorbable antibiotic beads in VSSIs remains controversial. While this cohort study demonstrated an increased risk of re-infection, this is confounded by the antibiotic bead group having a higher frequency of graft infections. Antibiotic beads appear to be safe for use in patients with vascular graft infections and may help achieve outcomes comparable to patients without graft involvement. Further studies with larger patient populations and similar infection severity between groups are needed.

A systematic review and meta-analysis of outcomes associated with development of surgical site infection after lower-limb revascularization surgery

OBJECTIVES

Although surgical site infection (SSI) is a commonly used quality metric after lower-limb revascularization surgery, outcomes associated with development of this complication are poorly characterized. We conducted a systematic review and meta-analysis of studies reporting associations between development of an SSI after these procedures and clinical outcomes and healthcare resource use.

METHODS

We searched MEDLINE, Embase, CENTRAL, and Evidence-Based Medicine Reviews (inception to April 4th, 2023) for studies examining adjusted associations between development of an SSI after lower-limb revascularization surgery and clinical outcomes and healthcare resource use. Two investigators independently screened abstracts and full-text citations, extracted data, and assessed risk of bias. Data were pooled using random-effects models. Heterogeneity was assessed using I2 statistics. GRADE was used to assess estimate certainty.

RESULTS

Among 6671 citations identified, we included 11 studies (n = 61,628 total patients) that reported adjusted-associations between development of an SSI and 13 different outcomes. Developing an SSI was associated with an increased adjusted-risk of hospital readmission (pooled adjusted-risk ratio (aRR) = 3.55; 95% CI (confidence interval) = 1.40-8.97; n = 4 studies; n = 13,532 patients; I2 = 99.0%; moderate certainty), bypass graft thrombosis within 30-days (pooled aRR = 2.09; 95% CI = 1.41-3.09; n = 2 studies; n = 23,240 patients; I2 = 51.1%; low certainty), reoperation (pooled aRR = 2.69; 95% CI = 2.67-2.72; n = 2 studies; n = 23,240 patients; I2 = 0.0%; moderate certainty), bleeding requiring a transfusion or secondary procedure (aRR = 1.40; 95% CI = 1.26-1.55; n = 1 study; n = 10,910 patients; low certainty), myocardial infarction or stroke (aRR = 1.21; 95% CI = 1.02-1.43; n = 1 study; n = 10,910 patients; low certainty), and major (i.e., above-ankle) amputation (pooled aRR = 1.93; 95% CI = 1.26-2.95; n = 4 studies; n = 32,859 patients; I2 = 83.0; low certainty). Development of an SSI >30-days after the index operation (aRR = 2.20; 95% CI = 1.16-4.17; n = 3 studies; n = 21,949 patients; low certainty) and prosthetic graft infection (aRR = 6.72; 95% CI = 3.21-12.70; n = 1 study; n = 272 patients; low certainty) were both associated with an increased adjusted-risk of major amputation. Prosthetic graft infection was also associated with an increased adjusted-risk of mortality >30-days after the index procedure (aRR = 6.40; 95% CI = 3.32-12.36; n = 1 study; n = 272 patients; low certainty).

CONCLUSIONS

This systematic review and meta-analysis suggests that development of an SSI after lower-limb revascularization surgery significantly increases patient morbidity and healthcare resource use. SSI is therefore a valuable quality metric after these surgeries. However, current estimates are based on heterogenous, low-to-moderate certainty evidence and should be confirmed by large, multicenter, cohort studies.

Tissue-engineered cellulose tubes for microvascular and lymphatic reconstruction: A translational and feasibility study

BACKGROUND

Lymphedema microsurgery is an emerging treatment modality, with dissimilar long-term outcomes. One of the main technical challenges in lymphatic microsurgery is the identification and availability of suitable donor vessels for anastomosis. Tissue engineering using biomaterials has demonstrated promise in addressing vessel quality issues in other fields, but its application in microsurgery is still limited.

METHODS

Decellularized cellulose tubes were developed and bioengineered by decellularizing stems of Taraxacum-Ruderalia. The microscopic structure, mechanical properties, and residual DNA content of the cellulose tubes were evaluated. Human and murine skin fibroblasts and dermal lymphatic endothelial cells were isolated and cultured for recellularization studies. Biocompatibility, proliferative capacity, and ex-vivo endothelialization of the cellulose tubes were assessed as potential interposition grafts. Finally, the engineered cellulose tubes were assessed as interposing xenografts for lymphovenous anastomoses (LVA) in an ex-vivo swine limb model.

RESULTS

The decellularized cellulose tubes exhibited a suitable microscopic structure, mechanical properties, and low residual DNA content. The tubes showed adequate biocompatibility, supported cell proliferation, and facilitated spontaneous ex-vivo endothelialization of lymphatic endothelial cells. In the swine limb model, LVA using the engineered cellulose tubes was successfully performed.

CONCLUSION

This translational study presents the use of decellularized cellulose tubes as an adjunct for micro and supermicrosurgical reconstruction. The developed tubes demonstrated favorable structural, mechanical, and biocompatible properties, making them a potential candidate for improving long-term outcomes in lymphedema surgical treatment. The next translational step would be trialing the obtained tubes in a microsurgical in-vivo model.

Cryopreserved arterial allografts vs autologous vein for arterial reconstruction in infected fields

OBJECTIVE

Peripheral arterial infections are rare and difficult to treat when an in situ reconstruction is required. Autologous vein (AV) is the conduit of choice in many scenarios. However, cryopreserved arterial allografts (CAAs) are an alternative. We aimed to assess our experience with CAAs and AVs for reconstruction in primary and secondary peripheral arterial infections.

METHODS

Data from patients with peripheral arterial infections undergoing reconstruction with CAA or AV from January 2002 through August 2022 were retrospectively analyzed. Patients with aortic- or iliac-based infections were excluded.

RESULTS

A total of 42 patients (28 CAA, 14 AV) with a mean age of 65 and 69 years, respectively, were identified. Infections were secondary in 31 patients (74%) and primary in 11 (26%). Secondary infections included 10 femoral-femoral grafts, 10 femoropopliteal or femoral-distal grafts, five femoral patches, four carotid-subclavian grafts, one carotid-carotid graft, and one infected carotid patch. Primary infection locations included six femoral, three popliteal, and two subclavian arteries. In patients with lower extremity infections, associated groin infections were present in 19 (56%). Preoperative blood cultures were positive in 17 patients (41%). AVs included saphenous vein in eight and femoral vein in six. Intraoperative cultures were negative in nine patients (23%), polymicrobial in eight (21%), and monomicrobial in 22 (56%). Thirty-day mortality occurred in four patients (10%), two due to multisystem organ failure, one due to graft rupture causing acute blood loss and myocardial infarction, and one due to an unknown cause post-discharge. Median follow-up was 20 months and 46 months in the CAA and AV group, respectively. Graft-related reintervention was performed in six patients in the CAA group (21%) and one patient in the AV group (7%). Freedom from graft-related reintervention rates at 3 years were 82% and 92% in the CAA and AV group, respectively (P = .12). Survival rates at 1 and 3 years were 85% and 65% in the CAA group and 92% and 84% in the AV group (P = .13). Freedom from loss of primary patency was similar with 3-year rates of 77% and 83% in the CAA and AV group, respectively (P = .25). No patients in either group were diagnosed with reinfection.

CONCLUSIONS

CAAs are an alternative conduit for peripheral arterial reconstructions when AV is not available. Although there was a trend towards higher graft-related reintervention rates in the CAA group, patency is similar and reinfection is rare.

Extra-anatomic Bypass and Excision is Superior to Graft Salvage Attempts with Antibiotic Beads to Treat Vascular Graft Infections in the Groin

OBJECTIVES

To determine if conventional extra-anatomic bypass and graft removal vs aggressive attempts at graft preservation has better survival and limb salvage in patients with localized groin wound infections of vascular grafts.

METHODS

We conducted a retrospective review of 53 consecutive patients with vascular graft infections presenting in the groin. Treatment groups consisted of group 1) extra-anatomic bypass and graft excision (N=22) and group 2) initial graft preservation attempts with utilization of antibiotic beads (N=31). In group 2, patients underwent serial debridement and placement of antibiotic beads until culture negative wounds were achieved. Significantly more patients underwent muscle flap coverage in group 2 (27 of 31) compared to group 1 (7 of 22) (p<0.001). Data collected included demographics, comorbidities, intraoperative details, and outcomes including patency, limb salvage, mortality, and number of procedures. Continuous variables were examined with Student's t-test and dichotomous variables were examined with Chi-Squared. Linear and logistic regression were used to analyze factors associated with outcomes, and Kaplan-Meier with log rank.

RESULTS

Both groups were similar with respect to demographics. The overall Kaplan-Meier 1- and 3-year survival rates were 66.2% and 34.1% with no statistically significant difference between groups. The Kaplan-Meier 1- and 3-year limb salvage rates were 68.8% and 36.6% for group 1 vs 58.5% and 38.7% for group 2 (p=NS). The 1- and 3-year primary patency rates were 71% and 71% in traditional group 1 vs 72% and 56% in group 2 (p=NS). 1- and 3-year secondary patency rates in traditional group 1 were 83% and 71% vs 85% and 61% in group 2 (p=NS). Patients in group 1 underwent fewer total procedures when compared to group 2 (2.3+.2 vs 5.1 +.7, p=0.03). The late reinfection rate was significantly less in group 1- 4.5% vs group 2- 26% (p=0.04). Freedom from reinfection at 1- and 3-years was 94% and 94% in traditional group 1 vs 74% and 62% in group 2 (p=0.03). Multivariable analysis showed a higher incidence of amputation in patients who suffered reinfection (N=13, p=0.049). There was a higher mortality in patients with septic shock (N=10, p=0.007) and reinfection (N=13, p=0.036). Reinfection was associated with the highest mortality (p=0.03).

CONCLUSIONS

Conventional graft excision with extra-anatomic bypass resulted in similar mortality when compared to aggressive attempts at graft preservation, and trended towards improved limb salvage and patency. However, attempts at graft preservation with antibiotic beads resulted in a significantly higher reinfection rate and greater number of procedures, and therefore this approach should be used very selectively.

Risk Factors and Consequences of Graft Infection after Femoropopliteal Bypass: A 25-year Experience

INTRODUCTION

In this multi-institutional series, we aimed to determine the incidence, risk factors, and long-term outcomes of graft infection in patients post-femoropopliteal bypass.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures from 1995-2020. Cumulative incidence function estimated the long-term rate of bypass graft infection (BGI) and Fine-Gray model was used to determine independent risk factors for BGI to account for death as a competing risk.

RESULTS

Over the 25-year period, 1315 femoral popliteal bypasses were identified with a median follow-up of 2.89 years (IQR 0.75-6.55). BGI was diagnosed in 34 (2.6%) patients. BGI occurred between 9 days and 11.2 years postoperatively, with a median 109 days. Estimated 1- and 5-year incidence of BGI was 2.1% (95% CI, 1.4-3.1%) and 2.8% (95% CI, 1.9-3.9%) respectively. Medical comorbidities, indications for bypass, and popliteal bypass targets (above- vs below-knee) were similar between BGI patients and all patients (p=NS each). Patients with BGI were more frequently complicated by postoperative hematoma (14.7% vs 3.7%), superficial wound infection (38.2% vs 19.2%), lymphocele/lymphorrhea (8.8% vs 2.1%), and 30-day readmission rates (47.1% vs 21.3%) (p<0.05 each). Most commonly isolated pathogens were Staphylococcus aureus (n=19, 55.9%) and polymicrobial cultures (n=5, 14.7%). Reoperation for BGI involved incision and drainage (n=7, 20.6%), graft excision without reconstruction (n=12, 35.3%), graft excision with in-line reconstruction (n=11, 32.4%), and graft excision with extra-anatomic reconstruction (n=2, 5.9%). Nine BGI patients (26.5%) ultimately required major amputation. Prosthetic bypass (subdistribution hazard ratio [SHR] 3.73 [1.64-8.51], p=0.002), postoperative hematoma (SHR 3.44 [1.23-9.61], p=0.018), and 30-day readmission (SHR 2.75 [1.27-5.44], p=0.010) were independently associated with BGI. One-year amputation-free survival was 50% (95% CI, 31.9-65.7%) after BGI.

CONCLUSIONS

BGI is a rare complication of femoral-popliteal bypass with significant morbidity. Graft infection is associated with the use of prosthetic grafts, postoperative hematoma, and unplanned hospital readmission. Mitigation of these risk factors may decrease the risk of this dreaded complication.

Tratamento híbrido para revascularização de membro inferior em paciente com infecção de prótese vascular: relato de caso

Patients with severe arterial obstructive disease and critical limb ischemia associated with vascular graft infection have elevated morbidity and mortality rates and are at high risk of limb loss. We present the case of a 76-year-old male patient with left lower limb critical ischemia and a femoropopliteal vascular graft infection. We used a hybrid treatment approach with an open surgical approach to the inguinal and popliteal regions and used the vascular prosthesis as endovascular access for direct recanalization of the superficial femoral artery, because the long occlusion and extensive calcification had frustrated initial attempts at endovascular treatment. After endovascular recanalization, the infected graft was removed. Used in conjunction with open surgery, advances in endovascular techniques and materials offer new solutions for patients when usual procedures fail.

Hybrid treatment for lower limb revascularization in a patient with vascular graft infection: a case report

Abstract Patients with severe arterial obstructive disease and critical limb ischemia associated with vascular graft infection have elevated morbidity and mortality rates and are at high risk of limb loss. We present the case of a 76-year-old male patient with left lower limb critical ischemia and a femoropopliteal vascular graft infection. We used a hybrid treatment approach with an open surgical approach to the inguinal and popliteal regions and used the vascular prosthesis as endovascular access for direct recanalization of the superficial femoral artery, because the long occlusion and extensive calcification had frustrated initial attempts at endovascular treatment. After endovascular recanalization, the infected graft was removed. Used in conjunction with open surgery, advances in endovascular techniques and materials offer new solutions for patients when usual procedures fail.

Vascular grafts collagen coating resorption and healing process in humans

Background

The objective of the present study was to evaluate the bioresorption rate of collagen coating (CC) sealed on textile vascular grafts (VGs) and their healing in humans using histologic analysis of explanted VGs.

Methods

A total of 27 polyester textile VGs had been removed during surgery from 2012 to 2020. The segments underwent histologic assessment. The CC bioresorption rate was assessed using morphometric analysis to determine the internal and external capsule thickness, inflammatory reaction degree, presence of neovessels, and endothelial cell layer.

Results

A total of 27 VGs were explanted from 25 patients because of infection (n = 5; 18.5%), thrombosis (n = 7; 25.9%), stenosis (n = 2; 7.4%), rupture (n = 4; 14.8%), aneurysmal degeneration (n = 3; 11.1%), revascularization (n = 4; 14.8%), or another cause (n = 2; 7.4%), with a median implantation duration of 291 days (interquartile range [IQR], 48-911 days). VGs with remaining CC (n = 7; 26%) had been explanted earlier than had those without (n = 20; 74%; 1 day [IQR, 1-45 days] vs 516 days [IQR, 79-2018 days]; P = .001). After 1 year, no remaining CC was detected on the analyzed VG sections. VGs implanted for <90 days had had a greater CC maximal thickness (63.90 μm [IQR, 0-83.25 μm] vs 0 μm [IQR, 0-0 μm]; P = .006) and a greater CC surface coverage (180° [IQR, 0°-360°] vs 0° [IQR, 0°-0°]; P = .002) than those implanted for >90 days. VGs implanted for >90 days had a greater external capsule thickness (889.2 μm [IQR, 39.6-1317 μm] vs 0 μm [IQR, 0-0 μm]; P = .002), a higher number of inflammatory mononuclear cells and giant cells (168 cells [IQR, 110-310 cells] vs 0 cells [IQR, 0-94 cells]; P < .0001) and a higher number of neovessels (4 [IQR, 0-5] vs 0 [IQR, 0-0]; P = .001) than those implanted for <90 days.

Conclusions

CC had a slow bioresorption rate in humans. Complete healing was never achieved, with no endothelial coverage observed. This finding implies that CC might not help graft healing.

The objective of the present study was to evaluate the bioresorption rate of collagen coating (CC) sealed on explanted textile vascular grafts (VGs) and their healing in humans using histologic analyses. We found that CC had a slow bioresorption rate in humans. Complete healing was never achieved, and no endothelial coverage was observed. Therefore, we question their use in daily practice because the faster healing potential of CC VGs has been an argument advanced by manufacturers for their use. Knowledge of the mechanisms of graft healing is necessary to understand the success and failure of the current bypass grafts.

Treatment of Early Deep Wound Infections after Arterial Reconstructions: A Meta-Analysis and Survey

BACKGROUND

Peripheral vascular graft infections, a serious concern after open lower extremity interventions, are treated using multiple strategies. Yet, there is no consensus on the optimal treatment. This study summarizes the literature and compares aggregate effect sizes between graft preservation with antibiotic beads and total graft excision.

METHODS

Manuscripts published between 1972 and 2019 were systematically queried using Ovid Medline and PubMed. Studies were included if they described early (≤4 months of the index procedure) infection-related outcomes after extracavitary and infrainguinal arterial graft infections that were managed with antibiotic-loaded beads or total excisions. Outcomes assessed included the prevalence of graft preservation failure, reinfection, and major amputation. To examine current preferences on this subject, a voluntary, anonymous survey was administered to practicing members of the Society for Clinical Vascular Surgery.

RESULTS

Six graft preservation studies (n = 147 patients) were included in the meta-analysis, based on PRISMA guidelines. The meta-analytic pooled proportion of patients with: (1) graft preservation failure was 0.09 (95% CI: 0.00, 0.46, I² = 88.8%), (2) reinfection was 0.04 (95% CI: 0.00, 0.18, I² = 79.7%), and (3) major amputation was 0.00 (95% CI: 0.00, 0.04, I² = 0%). Five studies addressing total excisions were identified via the systematic review however, their combined sample size (n = 28 patients) impeded use of a meta-analysis. Ninety (19%) licensed surgeons participated in the survey. In a hemodynamically stable, nonseptic patient, 67% (60) of respondents routinely excise the graft, while 31% (28) prefer preservation.

CONCLUSIONS

Study design and patient characteristic-related heterogeneity limited our ability to generate robust, clinical evidence-level outcome estimates. A prospective study is necessary to definitively establish the efficacy of antibiotic beads in the treatment and preservation of vascular graft infections.

Total Resection of Infected Peripheral Hemodialysis Grafts Has a Favorable Impact on Outcomes

BACKGROUND

Surgical resection could be an eradication treatment for patients with infected hemodialysis arteriovenous grafts (AVGs). This study aimed to investigate the outcomes of 3 surgical methods, including total resection, subtotal resection, and revision.

METHODS

The patients who underwent surgical excision of infected AVGs performed at a single center from August 2012 to March 2019 were retrospectively analyzed. The following 3 surgical methods were used in our study: revision, subtotal resection, and total resection. Patients' demographics, medical history, perioperative details, reconstruction time, and follow-up data were collected. The outcomes including perioperative complications (within 30 days), mortality, reinfection rate of AVGs, with new access reconstruction or not, and the outcomes between reconstruction and nonreconstruction in the follow-up period were evaluated.

RESULTS

Forty-one patients had infected AVGs in our study. Patients' mean age was 62 years, and 65.9% of the patients were female. The mean duration from the time of diagnosis to the operation was 14.4 days. Signs and symptoms at presentation included fever (51.2 %), swelling (43.9%), pain (58.5%), erythematous change (92.7%), and more severe features, such as altered consciousness (14.6%) and hypotension (12.2%). The pathological changes in the infected grafts included bleeding (29.3%), pus formation (73.2%), pseudoaneurysm (26.8%), and graft exposure (17.1%). Wound and graft cultures revealed an infectious etiology with fungi (7.3%), Pseudomonas aeruginosa (12.2%), Enterococcus spp. (2.4%), and Staphylococcus spp. (58.5%), with methicillin-resistant Staphylococcus aureus accounting for only 7.3%. Total resection, subtotal resection, and revision surgery were performed in 17.1%, 63.4%, and 19.5% of patients, respectively. Seven patients with complications required reoperation (17.1%), and adhesion ileus and hospital-acquired pneumonia occurred in only 2.4% and 7.3% of patients, respectively. During follow-up, most patients (82.9%) had reconstruction of the peripheral hemodialysis access with mean time of 64.3 (range: 21-92) days; mean time of use of new access was 90.5 days; and mean time of removal of catheter was about 106.3 days. Mortality rates in patients without and with reconstructed AV access during follow-up were 50% and 18%, respectively (P < 0.004). Eight cases (19.5%) had recurrence of AV access infections during follow-up; of these, 2 had revision surgery and 6 had subtotal resection. However, no patient with total resection had recurrent infections.

CONCLUSIONS

The total resection group had no recurrent infection compared to the subtotal and revision groups. In addition, patients with reconstruction of peripheral hemodialysis access had a low mortality rate during the follow-up period.

Contemporary management and outcomes of complex vascular surgical groin wound infections

OBJECTIVE

Vascular surgical groin wound infection (VS-GWI) has multiple causes and frequently is manifested as a limb- or life-threatening problem, resulting in significant morbidity and mortality. For patients undergoing operative extirpation, in situ repair, extra-anatomic bypass, or ligation can be used; however, limited data exist describing comparative results of the different operative choices or conduit subtypes. Therefore, we sought to describe our experience with management of VS-GWI and to detail outcomes of the different strategies.

METHODS

Patients (2003-2017) undergoing surgical treatment of VS-GWI (Szilagyi grade III) secondary to primary infectious arteritis or infected pseudoaneurysm after percutaneous intervention as well as previous prosthetic graft placement were reviewed. The primary end point was major adverse limb events (MALEs; major amputation, graft occlusion, or unplanned reintervention). Secondary end points included 30-day mortality, wound healing, amputation-free survival (AFS), and all-cause mortality. Cox proportional hazards modeling was used to determine relative risk of end points; Kaplan-Meier methodology was employed to estimate freedom from outcomes.

RESULTS

There were 149 patients (age, 65 ± 11 years; body mass index, 27 ± 6 kg/m²; 70% male; 32% diabetes) identified, of whom 120 (81%) had unilateral and 29 (19%) had bilateral VS-GWI. Indications included infected prosthetic bypass (88% [n = 131]; infrainguinal, 107; suprainguinal, 24) and primary infectious femoral artery complications (12% [n = 18]). A majority underwent single-stage operations (87% [n = 129]). In situ reconstruction occurred in 87% (n = 129); 9% (n = 13) underwent ligation, and 6% (n = 7) received extra-anatomic revascularization. Autogenous conduit was used most commonly (68% [n = 101/149]; 88% single stage), of which 81% (n = 80) were femoral vein. The remaining patients received cadaveric (15% [n = 23]; 87% single stage) or prosthetic (8% [n=12]; 67% single stage) grafts. Adjunctive myocutaneous flap was used in 37% (n = 54). Length of stay was 19 ± 15 days and 30-day mortality was 7% (n = 10), with no difference between conduit repair types. All femoral wounds healed (mean follow-up, 17 ± 11 months); however, 33% (n = 49) underwent reoperation (unplanned graft reintervention, 33%; graft occlusion, 16%; wound débridement, 15%; major amputation, 11%). Reinfection occurred in 17% (n = 27), with no difference between groups. MALE rate was 22% (n = 33; most were arterial reinterventions, 19%), with no difference in single-stage vs multistage, in situ vs extra-anatomic, or autogenous vs nonautogenous conduit strategies Predictors of MALE included younger age (hazard ratio [HR], 1.6 per decade; 95% confidence interval [CI], 1.1-2.5; P = .02) and lower body mass index (<25 kg/m²; HR, 1.6 per BMI category; 95% CI, 1.1-2.5; P = .02). Overall, 1- and 3-year freedom from MALE, AFS, and survival were as follows: MALE, 74% ± 5% and 63% ± 6%; AFS, 68% ± 4% and 58% ± 5%; survival, 78% ± 3% and 70% ± 4%. Autogenous conduit use was associated with better survival (HR, 0.5; 95% CI, 0.3-0.8; 1-year: 83% ± 4% vs nonautogenous, 78% ± 4%; 3-year: 68% ± 8% vs 53% ± 9%; log-rank, P = .006).

CONCLUSIONS

An individualized approach to operative strategy and conduit choice leads to comparable outcomes in this challenging group of patients. VS-GWI can be safely managed with in situ, autogenous reconstruction in a majority of patients with acceptable mortality, excellent wound healing rates, and improved overall survival. However, a significant proportion of patients experience reinfection and MALEs, the preponderance of which are arterial reintervention, mandating need for close follow-up and graft surveillance.

Percutaneous Continuous Irrigation and Drainage for Infected Obturator Bypass Graft

The treatment for obturator bypass graft infection has been rarely reported and is a surgical challenge because it is difficult to debride infected tissue around the graft located in the deep route and to ensure an alternative revascularization route in patients with a history of inguinal infection. Percutaneous continuous irrigation and drainage is an effective and less invasive definitive therapy for obturator bypass graft infection.

Vascular Graft Infections: An update

Vascular graft infection is a devastating complication of vascular reconstructive surgery. The infection can occur early in the postoperative period and is largely due to intraoperative contamination or by contiguous extension from a nearby infection. It can also occur years after implantation. Staphylococci remain the most common organisms and biofilm production makes eradication difficult. Factors commonly reported to predispose to vascular graft infection are periodontal disease, nasal colonization with Staphylococcus aureus, bacteremia, certain graft characteristics, diabetes mellitus, postoperative hyperglycemia, location of the incision, wound infection, and emergency procedure. Management consists of antibiotic and surgical therapy. Preventive methods are described.

Vein Patch Closure Using Below the Knee Greater Saphenous Vein for Femoral Endarterectomy Procedures is Not Always a Safe Choice

Background

The complication of vein patch rupture is well described after carotid patch angioplasty; however, there is a paucity of data about the safety of vein patch closure in the setting of femoral endarterectomy.

Methods/results

From May 2012 to May 2015, 115 femoral endarterectomies with patch closure were performed. A patch rupture occurred in three cases (2.6%) with a mortality rate of 66% (2/3). In all cases the greater saphenous vein below the knee was used as patch material.

Discussion/conclusion

Vein patches, particularly from small calibre veins, should be excluded in femoral endarterectomy procedures as they pose a substantial risk of rupture.

•

Choice of patch material for endarterectomy procedures of the common femoral artery may be crucial.

•

Patch rupture after use of the greater saphenous vein occurs in 3% of cases.

•

A particular risk of rupture occurs after the use of below knee greater saphenous vein patches.

•

Patch rupture is associated with a high mortality rate.

Managing Groin Wounds after Infrainguinal Vascular Procedures: Examining the Reoperative Events and Complication Profile of Muscle Flap Reconstruction

BACKGROUND

The literature has been void of large outcome studies detailing the efficacy and complication profile of muscle flap reconstruction of complex groin wounds. Furthermore, a first-line choice for muscle flap selection remains unclear. The aim of this study is 2-fold: (1) to examine the complication profile and associated risk factors following muscle flap coverage and (2) to provide a compared efficacy analysis of the sartorius muscle flap (SMF) versus the rectus femoris flap (RFF) in the treatment of wounds following an infrainguinal vascular procedure.

METHODS

A retrospective review of records was performed on all patients undergoing complex groin wound reconstruction from January 2005 to September 2014.

RESULTS

A total of 201 flaps were performed on 184 patients. There were no sentinel bleeding events through the course of graft salvage or perioperative morbidity beyond local wound complications. Coronary artery disease (P = 0.049), dyslipidemia (P < 0.001), diabetes (P = 0.047), and history of multiple prior infrainguinal procedures (P = 0.029) were associated with increased complications following groin wound reconstruction. There was no statistically significant difference in complications in comparing the RFF versus the SMF (27.9% vs. 38.9% respectively; P = 0.109). There was no significant difference in the rates of graft salvage in comparing the RFF versus the SMF (21.6% vs. 16.1%, respectively; P = 0.459).

CONCLUSIONS

Muscle flap coverage can be safely employed for vascular graft salvage. Medical comorbidities and multiple prior infrainguinal procedures are predictive of perioperative complications. The SMF and RFF demonstrated equivocal rates of complications and graft salvage. Given that the RFF risks increased functional morbidity and necessitates a second donor site, the SMF may be considered as an effective first-line approach for reconstruction of complex groin wounds.

Cryopreserved Human Allografts for the Reconstruction of Aortic and Peripheral Prosthetic Graft Infection

Background: This study aimed to present cases with cryopreserved human allografts (CHAs) for vascular reconstruction in both aortic and peripheral infected prosthetic grafts.

Materials and Methods: This is a single center, observational descriptive study with retrospective analysis. In all cases, the infected prosthetic graft material was completely removed. At discharge, patients were administered anticoagulants. Follow-up examinations included clinical visits, echo-color-Doppler ultrasounds, or computed tomography angiography within 30 days and at 3, 6, and 12 months after the treatment, and then twice per year.

Results: We treated 21 patients (90% men, n=19) with the mean age of 71±12 years and mean interval between the initial operation and replacement with CHA of 30 months [range, 1–216; interquartile range (IQR), 2–36]. In-hospital mortality was 14% (n=3); no CHA-related complication led to death. Limb salvage was 100%. No patient was lost at the median follow-up of 14 months (range, 2–61; IQR, 6–39). No rupture, aneurysmal degeneration, or re-infection occurred. Estimated freedom from CHA-related adverse events (95% confidence interval, 43–63) was 95% at 3 years.

Conclusion: In our experience, CHAs are a viable option for prosthetic graft infections and provide satisfactory clinical results and favorable stability because of a very low rate of CHA-related adverse events during follow-up.

Management of Infected Aortic Prosthetic Grafts

The management of infected prosthetic grafts is one of the most challenging problems facing vascular surgeons. High mortality and morbidity rates with traditional treatment have led many surgeons to consider different and novel strategies. Diagnosis is usually straightforward, but occasionally is unclear even after extensive clinical and radiologic investigations. Although routine total graft excision for all infected aortic grafts is still favored by some vascular surgeons, most favor only partial graft excision if only the distal limb of the graft is involved. Placement of in situ autologous vein or cryopreserved grafts have gained popularity, and investigations are continuing regarding the use of in situ antibiotic and silver-coated prosthetic grafts. In this article the authors review the incidence and etiology of aortic graft infections, methods to prevent these complications, the diagnosis of infected aortic grafts, and lastly the management of these complicated cases, including total graft excision and partial and complete graft preservation.

Management of Femoral Lymphatic Complications Following Synthetic Lower Extremity Revascularization: Early and Late Results

Lymphatic complications following synthetic graft placement in the groin may be associated with prolonged drainage leading to the development of wound infection, which may involve the underlying prosthetic graft. To determine associated early and late mortality and morbidity and to develop guidelines for optimal management, the authors reviewed their department's recent experience with this problem.

From 1982 to 1996, 32 femoral lymphatic complications (29 lymphocutaneous fistulas and 3 lymphoceles) were treated in 26 patients (16 men and 10 women, mean age 68 years) who had undergone lower extremity revascularization utilizing synthetic graft material. Patients with clinical evidence of graft infection or those with lymphatic complications following autogenous reconstructions were excluded from analysis. Underlying grafts involved the aortofemoral segment in 63% (20/32), the femorofemoral segment in 16% (5/32), the femorodistal segment in 13% (4/32), and the axillofemoral segment in 9% (3/32). Presenting symptoms were wound drainage in 27 limbs (91%), a groin mass in 3 (9%), and both in 6% (2/32). Management consisted of surgical exploration and lymphatic ligation with or without sclerosis in 24 limbs (75%) and local measures only in 8 (25%). Mean late follow-up was 3.6 years (range 0.1-8.9 years), and one patient was lost to follow-up at 3.1 years.

There were no 30-day postoperative deaths. One patient died of pneumonia at 34 days after treatment. The median interval from treatment to wound resolution was 5 days for the entire series and was significantly shorter (2 days) for the surgically treated limbs than for those treated conservatively (38 days) (P=0.0001). The median interval from treatment to hospital discharge was also shorter for the surgically treated limbs (11 days) than for those treated conservatively (26 days) (P=0.025). There were no late recurrences, amputations, or graft infections. Cumulative 5-year survival for the entire series was 53%.

Surgical repair of groin lymphocutaneous fistulas and lymphoceles following synthetic graft placement is safe and durable. This approach yields significantly shorter intervals from treatment to wound resolution and requires a shorter postoperative hospitalization period than the conservative approach.

Bio-absorbable antibiotic impregnated beads for the treatment of prosthetic vascular graft infections

OBJECTIVE

There is limited investigation into the use of bio-absorbable antibiotic beads for the treatment of prosthetic vascular graft infections. Our goal was to investigate the rates of infection eradication, graft preservation, and limb salvage in patients who are not candidates for graft explant or extensive reconstruction.

METHODS

A retrospective review of patients implanted with antibiotic impregnated bio-absorbable calcium sulfate beads at a major university center was conducted.

RESULTS

Six patients with prosthetic graft infections were treated with bio-absorbable antibiotics beads from 2012-2014. Grafts included an aortobifemoral, an aorto-hepatic/superior mesenteric artery, and four extra-anatomic bypasses. Pathogens included Gram-positive and Gram-negative bacteria. Half of the patients underwent graft explant with reconstruction and half debridement of the original graft, all with antibiotic bead placement around the graft. Mean follow-up was 7.3 ± 8.3 months; all patients had infection resolution, healed wounds, and 100% graft patency, limb salvage, and survival.

CONCLUSION

This report details the successful use of bio-absorbable antibiotic beads for the treatment prosthetic vascular graft infections in patients at high risk for graft explant or major vascular reconstruction. At early follow-up, we demonstrate successful infection suppression, graft preservation, and limb salvage with the use of these beads in a subset of vascular patients.

Surface modification of uniaxial cyclic strain cell culture platform with temperature-responsive polymer for cell sheet detachment

Current cell sheet-based blood vessels lack biomimetic structure and require excessively long culture times that may compromise smooth muscle cell phenotype. We modified a commercially available product for uniaxial cell sheet conditioning with thermoresponsive copolymers. Thus, culture of detachable conditioned cell sheets is shortened while retaining structural integrity and contractility.

The Tissue-Engineered Vascular Graft-Past, Present, and Future

Cardiovascular disease is the leading cause of death worldwide, with this trend predicted to continue for the foreseeable future. Common disorders are associated with the stenosis or occlusion of blood vessels. The preferred treatment for the long-term revascularization of occluded vessels is surgery utilizing vascular grafts, such as coronary artery bypass grafting and peripheral artery bypass grafting. Currently, autologous vessels such as the saphenous vein and internal thoracic artery represent the gold standard grafts for small-diameter vessels (<6 mm), outperforming synthetic alternatives. However, these vessels are of limited availability, require invasive harvest, and are often unsuitable for use. To address this, the development of a tissue-engineered vascular graft (TEVG) has been rigorously pursued. This article reviews the current state of the art of TEVGs. The various approaches being explored to generate TEVGs are described, including scaffold-based methods (using synthetic and natural polymers), the use of decellularized natural matrices, and tissue self-assembly processes, with the results of various in vivo studies, including clinical trials, highlighted. A discussion of the key areas for further investigation, including graft cell source, mechanical properties, hemodynamics, integration, and assessment in animal models, is then presented.

Less Than Total Excision of Infected Prosthetic PTFE Graft Does Not Increase the Risk of Reinfection

Background:

Traditional treatment of infected polytetrafluoroethylene (PTFE) grafts consist of removal of the entire prosthesis. Closure of the native vessels may compromise vascular patency. We examined the outcomes for patients in whom a PTFE remnant of an infected graft was retained on the vessel.

Methods:

We reviewed the operating room log from 2000 to 2011 and identified all patients who had partial removal of an infected PTFE graft used for hemodialysis or peripheral bypass. These patients were examined for subsequent complications.

Results:

Twenty-seven patients underwent 30 partial graft excisions with mean follow-up of 27 months. A total of 17% (5 of 30) of the partial graft resection procedures resulted in complications. Of 48 total remnants left behind at the arterial or venous anastomoses, reinfection occurred in 15%.

Conclusions:

Leaving a well-incorporated small 1-to 5-mm PTFE remnant at the arterial or venous anastomoses can be performed safely with a low risk of complications.

Treatment of surgical site infections (SSI) IN patients with peripheral arterial disease: an observational study

INTRODUCTION

The management of surgical site infections (SSI's) in vascular surgery has been challenging over the years. To assess the outcomes associated with the various strategies, we performed a review of all SSI's after elective vascular procedures in patients with moderate to severe peripheral arterial disease in a single centre hospital.

METHODS

All patients with a SSI after peripheral vascular surgery were retrieved from a database on Surgical site infections (SSI)-surveillance after vascular surgery between March 2009 and January 2012. At admission, all patients were approached by microbiological wound sampling and empirical start of antibiotics. Further wound management was based on personal experience and preference of the attending vascular surgeon. Endpoints were treatment success (complete wound healing while staying alive and without major amputation), survival and major amputation during one year follow up.

RESULTS

A total of 40 patients with a SSI were identified (60% superficial SSI and 40% deep SSI). In 92% of the patients with a superficial SSI's were successfully treated with adjusted antibiotics and incisional drainages. In the contrast, 25% of the patients with deep-SSI's were successfully treated. No particular treatment was more successful than the others.

CONCLUSION

Adjusted antibiotic use and adequate wound drainage are sufficient strategies for superficial SSI management. The management of deep-SSI's is a challenging undertaking and future research on indications and timing of these wide arrays of treatment options is suggested.

The vacuum-assisted closure (V.A.C®) system for surgical site infection with involved vascular grafts

BACKGROUND

In vascular surgery, surgical site infection is the most common postoperative morbidity, occurring in 5-10% of vascular patients. The optimal management of surgical site infection with involved lower limb vascular grafts remains controversial. We present our 6-year results of using the V.A.C.® system in surgical site infection with involved vascular grafts.

METHODS

A retrospective 6-year review of patient who underwent a VAC® therapy for postoperative surgical site infection in lower limb with involved vascular grafts in our department between January 2006 and December 2011. V.A.C therapy was used in 40 patients. All patients underwent surgical wound revision with VAC® therapy and antibiotics.

RESULTS

The mean time of use of the V.A.C. system was 14.2 days. After mean of 12 days in 34 of 40 patients, in whom the use of VAC® therapy resulted in delayed primary closure or healing by secondary intention. The mean postoperative follow-up time was 61.67 months, during which 3 patients died.

CONCLUSION

We showed that the V.A.C.® system is valuable for managing specifically surgical site infection with involved vascular grafts. Using the V.A.C.® system, reoperation rates are reduced; 85% of patients avoided graft replacement.

Long-term follow-up of last autogenous option arm vein bypass

BACKGROUND

The superiority of autogenous conduits in infrainguinal bypass surgery is well established. At our institution, arm vein is utilized as the last autogenous option for infrainguinal bypass surgery. The aim of this study was to review the long-term outcomes of last autogenous option arm vein bypass.

METHODS

All infrainguinal arm vein bypasses performed between 1997 and 2005 by The Queen Elizabeth Hospital vascular surgeons were identified. Patency, reintervention, limb salvage and survival were calculated using the Kaplan-Meier survival estimate method.

RESULTS

Thirty-eight arm vein bypasses were performed in 35 patients. Eighty-nine per cent were performed for critical limb ischaemia. Median follow-up was 58 months (range 2-121). Twelve-month primary, assisted primary and secondary patency rates were 52%, 73% and 76%, respectively. Three-year primary, assisted primary and secondary patency rates were 32%, 61% and 63%, respectively. Five-year primary, assisted primary and secondary patency rates were 21%, 47% and 49%, respectively. Patency was superior in single compared with spliced vein grafts (P < 0.05). Limb salvage rates at 1, 3 and 5 years were 94%, 87% and 76%, respectively. Patient survival at 1, 3 and 5 years was 92%, 68% and 49%, respectively.

DISCUSSION

Infrainguinal bypass surgery with arm vein can be performed safely with favourable patency and high rates of limb salvage. Secondary interventions to maintain patency are common and we recommend a vigilant surveillance programme to identify the threatened graft.

Prosthetic graft infections involving the femoral artery

BACKGROUND

Prosthetic graft infection is a major complication of peripheral vascular surgery. We investigated the experience of a single institution over 10 years with bypass grafts involving the femoral artery to determine the incidence and risk factors for prosthetic graft infection.

METHODS

A retrospective cohort single-institution review of prosthetic bypass grafts involving the femoral artery from 2001 to 2010 evaluated patient demographics, body mass index, comorbidities, indications, location of bypass, type of prosthetic material, case urgency, and previous ipsilateral bypass or percutaneous interventions and evaluated the incidence of graft infections, amputations, and mortality.

RESULTS

There were 496 prosthetic grafts identified with a graft infection rate of 3.8% (n = 19) at a mean follow-up of 27 months. Multivariable analysis showed that redo bypass (hazard ratio [HR], 5.8; 95% confidence interval [CI], 2.2-15.0), active infection at the time of bypass (HR, 5.2; 95% CI, 1.9-14.2), female gender (HR, 4.5; 95% CI, 1.6-12.7), and diabetes mellitus (HR, 4.6; 95% CI, 1.5-14.3) were significant predictors of graft infection. Graft infection was predictive of major lower extremity amputation (HR, 9.8; 95% CI, 3.5-27.1), as was preoperative tissue loss (HR, 4.7; 95% CI, 1.8-11.9). Graft infection did not predict long-term mortality; however, chronic renal insufficiency (HR, 2.3; 95% CI, 1.6-3.4), tissue loss (HR, 1.4; 95% CI, 1.0-1.9), and active infection (HR, 2.3; 95% CI, 1.6-3.4) did. Infected grafts were removed 79% of the time. Staphylococcus epidermidis (37%) and methicillin-sensitive Staphylococcus aureus (26%) were the most common pathogens isolated.

CONCLUSIONS

Redo bypass, female gender, diabetes, and active infection at the time of bypass are associated with a higher risk for prosthetic graft infection and major extremity amputation but do not confer an increased risk of mortality. Autologous vein for lower extremity bypass and endovascular interventions should be considered when feasible in high-risk patients.

Incidence and clinical implication of nosocomial infections associated with implantable biomaterials - catheters, ventilator-associated pneumonia, urinary tract infections

Health care associated infections, the fourth leading cause of disease in industrialised countries, are a major health issue. One part of this condition is based on the increasing insertion and implantation of prosthetic medical devices, since presence of a foreign body significantly reduces the number of bacteria required to produce infection. The most significant hospital-acquired infections, based on frequency and potential severity, are those related to procedures e.g. surgical site infections and medical devices, including urinary tract infection in catheterized patients, pneumonia in patients intubated on a ventilator and bacteraemia related to intravascular catheter use. At least half of all cases of nosocomial infections are associated with medical devices.Modern medical and surgical practices have increasingly utilized implantable medical devices of various kinds. Such devices may be utilized only short-time or intermittently, for months, years or permanently. They improve the therapeutic outcome, save human lives and greatly enhance the quality of life of these patients. However, plastic devices are easily colonized with bacteria and fungi, able to be colonized by microorganisms at a rate of 0.5 cm per hour. A thick biofilm is formed within 24 hours on the entire surface of these plastic devices once inoculated even with a small initial number of bacteria.The aim of the present work is to review the current literature on causes, frequency and preventive measures against infections associated with intravascular devices, catheter-related urinary tract infection, ventilator-associated infection, and infections of other implantable medical devices. Raising awareness for infection associated with implanted medical devices, teaching and training skills of staff, and establishment of surveillance systems monitoring device-related infection seem to be the principal strategies used to achieve reduction and prevention of such infections. The intelligent use of suitable antiseptics in combination with medical devices may further support reduction and prevention of such infections. In addition to reducing the adverse clinical outcomes related with these infections, such reduction may substantially decrease the economic burden caused by device-related infection for health care systems.

Successful Surgical Treatment of Methicillin-Resistant Staphylococcus Aureus (MRSA) Vascular Graft Infection

A 54-year-old man was referred to our hospital because of a false aneurysm in his right groin following Aortobifemoral and femoropopliteal bypass surgery. He underwent false aneurysm repair and infrainguinal arterial reconstruction. He then developed MRSA sepsis in the right groin. The patient underwent a number of operations to remove the infected grafts and distal revascularization to allow limb salvage. His last operation was an iliofemoral bypass via extra-anatomical route, from just below the iliac crest into the popliteal artery using an 8 mm-ringed polyester gelatin polypropylene tube graft, with complete debridement of a groin infection. Postoperative duplex scan and 3-dimentional CT angiography revealed a patent prosthetic graft and the patient made uneventful postoperative recovery. We conclude that this extra-anatomical bypass is a safe technique and a good option for patients with an infected vascular prosthetic graft in the groin after previous revascularization.

Development of the novel biotube inserting technique for acceleration of thick-walled autologous tissue-engineered vascular grafts fabrication

To accelerate the fabrication of thick-walled autologous tissue-engineered vascular grafts (TEVGs), a novel biotube inserting technique was developed. After 2 weeks of subcutaneous embedding in rabbits, silicone rods (diameter, 3 mm; length, 35 mm) became encapsulated in connective tissues. Single-layered biotubes were obtained after removing the silicone rods. One silicone rod encapsulated in tissues was inserted into a single-layered biotube to form two layers of autologous tubular tissues. Three layers of autologous tubular tissues were also obtained by applying the same technique. Following a 2-week re-embedding procedure, two layers or three layers of autologous tubular tissues were integrated to form two-layered or three-layered TEVGs. Both wall thickness and burst pressure of three-layered TEVGs were significantly higher than those of two-layered and single-layered TEVGs (P < 0.05). The two-layered TEVGs could be applied as small-caliber vascular grafts, and three-layered TEVGs could be applied as medium- or large-caliber vascular grafts.

Management of vascular graft infections with soft tissue flap coverage: improving limb salvage rates--a veterans affairs experience

Graft infections are one of the most challenging issues in surgery with an incidence of 0.7 to 7 per cent, with femoral site infections being the most common (13% incidence). The gold standard treatment has been graft removal, wide débridement, and extra-anatomical bypass. Routine excision of infected peripheral arterial grafts and vascular reconstruction with extraanatomic conduits are associated with mortality rates ranging from 10 to 30 per cent and amputation rates of up to 70 per cent. As a result of the high morbidity and mortality associated with this approach, selective graft preservation techniques have been developed. Newer treatment plans discuss preservation of the graft with débridement and coverage of the infected region. Better wound care, nutrition optimization, and robust flap coverage have led to significantly improved graft salvage, lower amputation rates, and improved outcomes. The objective of this study was to evaluate the Veterans Affairs (VA) experience with flap coverage for femoral vascular graft infections. A retrospective review was conducted of all VA data from 1997 to 2008 with inclusion criteria of patients with deep groin wound infections requiring flap coverage after femoral bypass surgery. Eleven such patients were identified with a mean age of 73 years and with multiple comorbidities (hypertension, malnutrition, diabetes mellitus, chronic obstructive pulmonary disease, coronary artery disease, chronic renal insufficiency). Patients presented with wound drainage, exposed graft, hematoma, perigraft fluid collection, and pseudoaneurysm. Treatment protocol included: 1) aggressive débridement of the wound bed; 2) early soft tissue (flap) coverage; 3) wound vacuum assisted closure device or frequent dressing changes; and 4) skin graft once the bed was prepared. Eighty-two per cent of wounds had positive cultures with equal numbers of patients with Staphylococcus epidermidis, Pseudomonas, Escherichia coli (22%), and higher methicillin-resistant Staphylococcus aureus (33%), whereas in the literature Staphylococcus is the most common (greater than 50%). Average hospital length of stay was 94 days with average follow up at 10 months. Fifty-five per cent graft salvage (one Dacron [50%], two polytetrafluoroethylene [33%], two saphenous vein graft [100%], one cryovein [100%]) was achieved with 91 per cent limb salvage. Complications included graft blowout (two) requiring partial flap loss (one), retroperitoneal hematoma (one), limb loss (one), sepsis (one), and death (one). Infected vascular grafts remain a challenging problem requiring multidisciplinary care. Careful débridement and aggressive wound care followed by selective flap coverage appears to decrease morbidity and increase graft and limb salvage.

ECM-based materials in cardiovascular applications: Inherent healing potential and augmentation of native regenerative processes

The in vivo healing process of vascular grafts involves the interaction of many contributing factors. The ability of vascular grafts to provide an environment which allows successful accomplishment of this process is extremely difficult. Poor endothelisation, inflammation, infection, occlusion, thrombosis, hyperplasia and pseudoaneurysms are common issues with synthetic grafts in vivo. Advanced materials composed of decellularised extracellular matrices (ECM) have been shown to promote the healing process via modulation of the host immune response, resistance to bacterial infections, allowing re-innervation and reestablishing homeostasis in the healing region. The physiological balance within the newly developed vascular tissue is maintained via the recreation of correct biorheology and mechanotransduction factors including host immune response, infection control, homing and the attraction of progenitor cells and infiltration by host tissue. Here, we review the progress in this tissue engineering approach, the enhancement potential of ECM materials and future prospects to reach the clinical environment.