Descriptive Analysis of Amputation-Free Survival After First Time Infra-Inguinal Bypass Occlusion.

INTRODUCTION: Occlusion after infra-inguinal bypass surgery for peripheral artery disease is a major complication with potentially devastating consequences. In this descriptive analysis, we sought to describe the natural history and explore factors associated with long-term major amputation-free survival following occlusion of a first-time infra-inguinal bypass. METHODS: Using a prospective database from a tertiary care vascular center, we conducted a retrospective cohort study of all patients with peripheral artery disease who underwent a first-time infra-inguinal bypass and subsequently suffered a graft occlusion (1997-2021). The primary outcome was longitudinal rate of major amputation-free survival after bypass occlusion. Cox proportional hazard models were used to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to explore predictors of outcomes. RESULTS: Of the 1318 first-time infra-inguinal bypass surgeries performed over the study period, 255 bypasses occluded and were included in our analysis. Mean age was 66.7 (12.6) years, 40.4% were female, and indication for index bypass was chronic limb threatening ischemia (CLTI) in 89.8% (n = 229). 48.2% (n = 123) of index bypass conduits used great saphenous vein, 29.0% (n = 74) prosthetic graft, and 22.8% (n = 58) an alternative conduit. Median (interquartile range) time to bypass occlusion was 6.8 (2.3-19.0) months, and patients were followed for median of 4.3 (1.7-8.1) years after bypass occlusion. Following occlusion, 38.04% underwent no revascularization, 32.94% graft salvage procedure, 25.1% new bypass, and 3.92% native artery recanalization. Major amputation-free survival following occlusion was 56.9% (50.6%-62.8%) at 1 y, 37.1% (31%-43.3%) at 5 y, and 17.2% (11.9%-23.2%) at 10 y. In multivariable analysis, factors associated with lower amputation-free survival were older age, female sex, advanced cardiorenal comorbidities, CLTI at index procedure, CLTI at time of occlusion, and distal index bypass outflow. Initial treatment after occlusion with both a new surgical bypass (HR 0.44, CI: 0.29-0.67) or a graft salvage procedure (HR 0.56, CI: 0.38-0.82) showed improved amputation-free survival. One-year rate of major amputation or death were 59.8% (50.0%-69.6%) for those who underwent no revascularization, 37.9% (28.7%-49.0%) for graft salvage, and 26.7% (17.6%-39.5%) for new bypass. CONCLUSIONS: Long-term major amputation-free survival is low after occlusion of a first-time infra-inguinal bypass. While several nonmodifiable risk factors were associated with lower amputation-free survival, treatment after graft occlusion with either a new bypass or a graft salvage procedure may improve longitudinal outcomes.

Longer Operative Time for Lower Extremity Bypass Surgery is Associated With Inferior Outcomes.

INTRODUCTION: This study aims to assess the association of operative time with the postoperative length of stay and unplanned return to the operating room in patients undergoing femoral to below knee popliteal bypasses, stratified by autologous vein graft or polytetrafluoroethylene (PTFE). MATERIALS AND METHODS: A retrospective analysis of vascular quality initiative database (2003-2021). The selected patients were grouped into the following: vein bypass (group I) and PTFE (group II) patients. Each group was further stratified by a median split of operative time (i.e., 210 min for autologous vein and 155 min for PTFE) to study the outcomes. The outcomes were assessed by univariate and multivariate approach. RESULTS: Of the 10,902 patients studied, 3570 (32.7%) were in the autologous vein group, while 7332 (67.3%) were in the PTFE group. Univariate analysis revealed autologous vein and PTFE graft recipients that had increased operative times were associated with a longer mean postoperative length of stay and a higher incidence of all-cause return to the operating room. In PTFE group, patients with prolonged operative times were also found to be associated with higher incidence of major amputation, surgical site infection, and cardiovascular events, along with loss of primary patency within a year. CONCLUSIONS: For patients undergoing femoral to below knee popliteal bypasses using an autologous vein or PTFE, longer operative times were associated with inferior outcomes. Mortality was not found to be associated with prolonged operative time.

Infrapopliteal Bypass In Patients On Dialysis: Patency And Survival.

INTRODUCTION: Portugal has one of the highest prevalence of patients on a regular dialysis program. This population has a higher incidence of peripheral arterial disease with higher rates of postoperative morbidity and mortality. Our goal was to compare outcomes between dialysis and non-dialysis patients with chronic limb threatening ischemia (CLTI) submitted to infrapopliteal bypass. MATERIALS AND METHODS: A retrospective single-center study of infrapopliteal bypass for CLTI was performed between 2012 and 2019. Patients were divided in two groups based on dialysis status (group 1 incorporated patients on dialysis). Primary end point was 1-year freedom from CLTI. Secondary end points were limb-salvage, survival and primary (PP) and tertiary patency (TP) rates at 3 years of follow-up. RESULTS: A total of 352 infrapopliteal bypasses were performed in 310 patients with CLTI. Fourteen percent of the revascularizations were performed on dialysis patients (48/352). Median age was 73 years (interquartile range - IQR 15) and 74% (259/352) were male. Median follow-up was 26 months (IQR 42). Overall, 92% (325/352) had tissue loss and 44% (154/352) had some degree of infection. The majority of revascularization procedures were performed with vein grafts (61%, 214/352). The 30-day mortality was 4% (11/310), with no difference between groups (p = 0.627). Kaplan-Meier analysis showed no difference between groups regarding freedom from CLTI (76% vs. 79%; HR 0.96, CI 0.65-1.44, p=0.857), limb-salvage (70% vs. 82%; HR 1.40, CI 0.71-2.78, p=0.327) and survival (62% vs. 64%; HR 1.08, CI 0.60-1.94, p=0.799). PP rates were 39% in group 1 and 64% in group 2 (HR 1.71, CI 1.05-2.79, p=0.030). TP rates were not different between groups (57% and 78%; HR 1.79, CI 0.92-3.47, p=0.082). CONCLUSION: Infrapopliteal bypass for CLTI, on dialysis patients, resulted in lower PP rates. No differences were observed in freedom from CLTI, TP, limb salvage and survival.

Alternative vein bypass in octogenarians with chronic limb-threatening ischaemia.

BACKGROUND: Octogenarians are regarded as one of the frailest patient groups among the chronic limb-threatening ischaemia population with high perioperative morbidity and mortality rates. As a result, alternative vein bypass surgery in the absence of sufficient great saphenous vein is often not considered as a potential treatment option. The aim of this study was to compare the results of octogenarians undergoing alternative vein bypass surgery due to chronic limb-threatening ischaemia to younger patients. METHODS: A single-centre retrospective analysis of patients undergoing bypass surgery for chronic limb-threatening ischaemia with alternative autologous vein grafts between 1997 and 2018 was performed. Patients aged over 80 years were compared with those under 80 years. Graft patency rates were assessed and a risk factor analysis for limb loss was performed. RESULTS: In total, 592 patients underwent bypass surgery during the study interval. Twenty-one per cent (n = 126) of patients were 80 years or older. At 4 years, primary, primary-assisted and secondary patency as well as limb salvage rates were not significantly different between the two groups (46% versus 50%, 60% versus 66%, 69% versus 72%, 72% versus 77%, for octogenarians versus non-octogenarians respectively). Major amputations were performed in 27 (21%) octogenarians and 91 (20%) non-octogenarians (P = 0.190). No higher 30-day and long-term mortality rates nor morbidity rates were detected in the octogenarian group with a median follow-up time of 27 (interquartile range 12-56) months. Minor amputation, the reason for alternative vein grafts, as well as the profunda femoris artery as proximal origin of the bypass were risk factors for limb loss in the postoperative course. CONCLUSION: Alternative vein bypass surgery in octogenarians with chronic limb-threatening ischaemia is safe and effective in terms of patency rates, limb salvage and survival compared with younger patients in the absence of sufficient great saphenous vein. Age alone should not be a deterrent from performing bypass surgery.

Popliteal-to-Distal Extreme Bypass in Endovascular Era.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) is characterized by rest pain and tissue loss, with an annual mortality rate of 20% and amputation rate of 40%, if not treated. Open bypass surgery is recommended in CLTI, depending on the availability of good quality venous material, outflow artery patency, and surgical expertise. The aim of the study is to analyze primary patency, limb salvage, and survival rate in patients undergoing popliteal-to-distal bypass. METHODS: All consecutive patients who underwent popliteal-to-distal bypass surgery between January 2016 and December 2021 were enrolled in the study. Primary outcomes were primary patency, limb salvage, and overall survival. Secondary outcomes included amputation-free survival and secondary patency. RESULTS: Forty-nine patients were included during the study. Technical success was achieved in 100% of cases. Target outflow artery was in 27% (n. 13) of cases the anterior tibial artery, in 27% (n. 13) the dorsalis pedis, in 2% (n. 1) the peroneal artery, in 30% (n. 15) the retromalleolar tibial artery, in 10% (n. 5) the medial plantar artery, and in 4% (n. 2) the tarsal artery. Two-year primary patency was 85% ± 5. Secondary patency rates were 86% ± 3 at 2 years. The overall survival was 81% ± 6 at 2 years, the amputation-free survival was 70% ± 9, and the limb salvage rate was 81% ± 6. CONCLUSIONS: Popliteal-to-distal bypass requires high technical expertise to be performed. When a good autologous vein and adequate outflow artery are present, they can be feasible with good patency rates and overall survival.

Long-Term Outcomes of Anatomical and Extra-Anatomical Bypass for the Treatment of Unilateral Iliac Artery Lesions a Systematic Review Aggregated Data and Individual Participant Data Meta-Analysis.

BACKGROUND: We investigated the long-term safety and efficacy of anatomical and extra-anatomical bypass for the treatment of unilateral iliac artery disease. METHODS: A systematic search on PubMed, Scopus and Web of science for articles published by June 2023 was performed. We implemented a 2-stage individual participant data meta-analysis and pooled survival probabilities using the multivariate methodology of DerSimonian and Laird. The primary endpoint was primary patency at 5 and 10 years of follow-up. RESULTS: Ten studies encompassing 1,907 patients were included. The 5- and 10-year pooled patency rates for anatomical bypass were 83.27% (95% confidence interval (CI): 69.99-99.07) and 77.30% (95% CI: 60.32-99.04), respectively, with a mean primary patency time representing the duration individuals remained event-free for 10.08 years (95% CI: 8.05-10.97). The 5- and 10-year pooled primary patency estimates for extra-anatomical bypass were 77.02% (95% CI: 66.79-88.80) and 68.54% (95% CI: 53.32-88.09), respectively, with a mean primary patency time of 9.25 years, (95% CI: 7.21-9.68). Upon 2-stage individual participant data meta-analysis, anatomical bypass displayed a decreased risk for loss of primary patency compared to extra-anatomical bypass, hazard ratio 0.51 (95% CI: 0.30-0.85). The 5- and 10-year secondary patency estimates for anatomical bypass were 96.83% (95% CI: 90.28-100) and 96.13% (95% CI: 88.72-100), respectively. The 5- and 10-year secondary patency estimates for extra-anatomical bypass were 91.39% (95% CI: 84.32-99.04) and 85.05% (95% CI: 74.43-97.18), respectively, with non-statistically significant difference between the 2 groups. The 5- and 10-year survival for patients undergoing anatomical bypass were 67.99% (95% CI: 53.84-85.85) and 41.09% (95% CI: 25.36-66.57), respectively. The 5- and 10-year survival for extra-anatomical bypass were 70.67% (95% CI: 56.76-87.98) and 34.85% (95% CI: 19.76-61.44), respectively. The mean survival time was 6.92 years (95% CI: 5.56-7.89) for the anatomical and 6.78 years (95% CI: 5.31-7.63) for the extra-anatomical groups. The pooled overall 30-day mortality was 2.32% (95% CI: 1.12-3.87) with metaregression analysis displaying a negative association between the year of publication and mortality (ß =-0.0065, P < 0.01). Further analysis displayed a 30-day mortality of 1.29% (95% CI: 0.56-2.26) versus 4.02% (95% CI: 1.78-7.03), (P = 0.02) for studies published after and before the year 2000. Non-statistically significant differences were identified between the 2 groups concerning long-term and 30-day mortality outcomes. CONCLUSIONS: While we have demonstrated favorable long-term primary and secondary patency outcomes for both surgical techniques, anatomical bypass exhibited a reduced risk of primary patency loss potentially reflecting its inherent capacity to circumvent the anticipated disease progression in the distal aorta and the contralateral donor artery. The reduction in perioperative mortality observed in our review, coupled with the anachronistic demographic characteristics and inclusion criteria presented in the existing literature, underscores the imperative necessity for contemporary research.

Executive Summary: State-of-the-Art Review: Fostering Collaborative Teamwork-A Comprehensive Approach to Vascular Graft Infection Following Arterial Reconstructive Surgery.

Vascular graft infection (VGI) is one of the most serious complications following arterial reconstructive surgery. VGI has received increasing attention over the past decade, but many questions remain regarding its diagnosis and management. In this review, we describe our approach to VGI through multidisciplinary collaboration and discuss decision-making for challenging presentations. This document will concentrate on VGI that impacts both aneurysms and pseudoaneurysms excluding the ascending thoracic aorta.

Comparison of mortality and amputation after lower extremity bypass versus peripheral vascular intervention in patients with chronic limb-threatening ischemia and comorbid chronic kidney disease.

OBJECTIVE: Comorbid chronic kidney disease (CKD) is associated with worse outcomes for patients with chronic limb-threatening ischemia (CLTI). However, comparative effectiveness data are limited for lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) in patients with CLTI and CKD. We aimed to evaluate (1) 30-day all-cause mortality and amputation and (2) 5-year all-cause mortality and amputation for LEB vs PVI in patients with comorbid CKD. METHODS: Individuals who underwent LEB and PVI were queried from the Vascular Quality Initiative with Medicare claims-linked outcomes data. Propensity scores were calculated using 13 variables, and a 1:1 matching method was used. The mortality risk at 30 days and 5 years in LEB vs PVI by CKD was assessed using Kaplan-Meier and Cox proportional hazards models, with interaction terms added for CKD. For amputation, cumulative incidence functions and Fine-Gray models were used to account for the competing risk of death, with interaction terms for CKD added. RESULTS: Of 4084 patients (2042 per group), the mean age was 71.0 ± 10.8 years, and 69.0% were male. Irrespective of CKD status, 30-day mortality (hazard ratio [HR]: 0.94, 95% confidence interval [CI]: 0.63-1.42, P = .78) was similar for LEB vs PVI, but LEB was associated with a lower risk of 30-day amputation (sub-HR [sHR]: 0.66, 95% CI: 0.44-0.97, P = .04). CKD status, however, did not modify these results. Similarly, LEB vs PVI was associated with a lower risk of 5-year mortality (HR: 0.79, 95% CI: 0.71-0.88, P < .001) but no difference in 5-year amputation (sHR: 1.03, 95% CI: 0.89-1.20, P = .67). CKD status did not modify these results. CONCLUSIONS: Regardless of CKD status, patients had a lower risk of 5-year all-cause mortality and 30-day amputation with LEB vs PVI. Results may help inform preference-sensitive treatment decisions on LEB vs PVI for patients with CLTI and CKD, who may commonly be deemed too high risk for surgery.

Infra-inguinal bypass surgery vs endovascular revascularization for chronic limb-threatening ischemia in average- and high-risk patients.

OBJECTIVE: This study aimed to evaluate treatment outcomes after bypass surgery or endovascular therapy (EVT) in average- and high-risk patients with chronic limb-threatening ischemia (CLTI). METHODS: We retrospectively analyzed multicenter data of patients who underwent infra-inguinal revascularization for CLTI between 2015 and 2022. A high-risk patient was defined as one with estimated 30-day mortality rate ≥5% or 2-year survival rate ≤50%, as determined by the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) calculator. The amputation-free survival (AFS), limb salvage (LS), wound healing, and 30-day mortality were compared separately for the average- and high-risk patients between the bypass and EVT with propensity score matching. RESULTS: We analyzed 239 and 31 propensity score-matched pairs in the average- and high-risk patients with CLTI. In the average-risk patients, the 2-year AFS and LS rates were 78.1% and 94.4% in the bypass group and 63.0% and 87.7% in the EVT group (P < .001 and P = .007), respectively. The 1-year wound healing rates were 88.6% in the bypass group and 76.8% in the EVT group, respectively (P < .001). The 30-day mortality was 0.8% in the bypass surgery and 0.8% in the EVT group (P = .996). In the high-risk patients, there was no differences in the AFS, LS, and wound healing between the groups (P = .591, P = .148, and P = .074). The 30-day mortality was 3.2% in the bypass group and 3.2% in the EVT group (P = .991). CONCLUSIONS: Bypass surgery is superior to EVT with respect to the AFS, LS, and wound healing in the average-risk patients. EVT is a feasible first-line treatment strategy for high-risk patients with CLTI undergoing revascularization, based on the lack of significant differences in the 2-year AFS rate, between the bypass surgery and EVT cohorts.

Autologous Alternative Vein Grafts for Infrainguinal Bypass in the Absence of Single-Segment Great Saphenous Vein: A Single-Center Study.

BACKGROUND: Alternative autologous veins can be used as a conduit when adequate great saphenous vein is unavailable. We analyzed the results of our infrainguinal bypasses after adopting upper extremity veins in our practice. METHODS: This is a single-center observational study involving all patients whose infrainguinal bypass involved the use of upper extremity veins between April 2019, when we began using arm veins, and February 2023. RESULTS: During the study period, 49 bypasses were done in 48 patients; mean age 68.1 ± 9.8; men 32 (66.7%); body mass index 28.0 ± 4.8; indications for surgery: chronic limb threatening ischemia 41 (83.7%); acute limb ischemia 3 (6.1%); complications of previous prosthetic 3 (6.1%), or autologous 2 (4.1%) bypass grafts. Vein splicing was used in 43 (87.8%) bypasses with 3-segment grafts being the most common (26; 53.1%). There were 24 (49.0%) femorotibial, 11 (22.4%) femoropopliteal, 9 (18.4%) femoropedal, and 5 (10.2%) extension jump bypass procedures. Eighteen (36.7%) operations were redo surgeries. Twenty-one (42.9%) bypasses were formed using only arm veins. The median follow-up was 12.9 months (4.5-24.2). Two bypasses occluded during the first 30 postoperative days (2/49; 4.1%). Overall 30-day, 1-year, and 2-year primary patency rates were 93.7% ± 3.5%, 84.8% ± 5.9%, and 80.6% ± 6.9%, and secondary patency (SP) rates were 95.8% ± 2.9%, 89.2% ± 5.3%, and 89.2% ± 5.3%. One-segment grafts had better patencies than 2-, 3-, and 4-segment grafts (1-year SP 100% ± 0% vs 87.6% ± 6.0%). Two-year amputation-free survival was 86.8% ± 6.5%; 2-year overall survival was 88.2% ± 6.6%. CONCLUSIONS: Integration of arm vein grafts in infrainguinal bypass practice can be done safely with low incidences of perioperative graft failure. One-segment grafts had better patencies than spliced vein grafts. The achieved early patency and amputation-free survival rates strongly encourage their use. In the absence of a single-segment great saphenous vein, upper extremity vein grafts should be the preferred conduit choice.

Using Isolated Femoral Bifurcation Endarterectomy or Combined with Bypass Surgery for Patients with Chronic Limb-Threatening Ischemia.

Background and Objectives: The aim of this study was to evaluate the clinical outcomes of patients suffering from chronic limb-threatening ischemia (CLTI) and tissue loss treated with primary isolated femoral bifurcation endarterectomy (FBE) or with FBE combined with bypass surgery. Materials and Methods: This retrospective study was performed in a tertiary university-based care centre. Between January 2008 and December 2019, a prospectively collected database of patients suffering from CLTI and tissue loss and undergoing either primary FBE (group A) or FBE in combination with bypass surgery (group B) was analysed. Study endpoints were ulcer healing, primary and secondary patency rate, limb salvage, and survival. Results: In total, FBE was performed in 73 patients and FBE with bypass in 60 patients. Between both groups, there were no significant differences regarding demographic data or the Global Limb Anatomic Staging System (GLASS) grade III and IV of femoropopliteal lesions. After 3 years, ulcer healing could be achieved in 72% of FBE and in 75% of FBE with bypass patients. The primary patency rate was 95% and 91% for FBE and 83% and 80% for FBE with bypass after one and three years, respectively. The 3-year limb-salvage rate was 78% for FBE and 84% for FBE with bypass. The secondary patency rate after one and three years was 99% and 97% for FBE and 93% and 88% for FBE with bypass. Conclusions: FBE and FBE with bypass are equally effective for ulcer healing in cases of combined CFA and superficial femoral artery lesions. There was no significant difference between both groups regarding primary and secondary patency rates, limb salvage rates and ulcer healing. Isolated FBE could be an alternative strategy in patients with higher operative risk.

Secondary interventions following open vs endovascular revascularization for chronic limb threatening ischemia in the BEST-CLI trial.

OBJECTIVES: Patients undergoing revascularization for chronic limb-threatening ischemia experience a high burden of target limb reinterventions. We analyzed data from the Best Endovascular versus Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) randomized trial comparing initial open bypass (OPEN) and endovascular (ENDO) treatment strategies, with a focus on reintervention-related study endpoints. METHODS: In a planned secondary analysis, we examined the rates of major reintervention, any reintervention, and the composite of any reintervention, amputation, or death by intention-to-treat assignment in both trial cohorts (cohort 1 with suitable single-segment great saphenous vein [SSGSV], n = 1434; cohort 2 lacking suitable SSGSV, n = 396). We also compared the cumulative number of major and all index limb reinterventions over time. Comparisons between treatment arms within each cohort were made using univariable and multivariable Cox regression models. RESULTS: In cohort 1, assignment to OPEN was associated with a significantly reduced hazard of a major limb reintervention (hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.28-0.49; P < .001), any reintervention (HR, 0.63; 95% CI, 0.53-0.75; P < .001), or any reintervention, amputation, or death (HR, 0.68; 95% CI, 0.60-0.78; P < .001). Findings were similar in cohort 2 for major reintervention (HR, 0.53; 95% CI, 0.33-0.84; P = .007) or any reintervention (HR, 0.71; 95% CI, 0.52-0.98; P = .04). In both cohorts, early (30-day) limb reinterventions were notably higher for patients assigned to ENDO as compared with OPEN (14.7% vs 4.5% of cohort 1 subjects; 16.6% vs 5.6% of cohort 2 subjects). The mean number of major (mean events per subject ratio [MR], 0.45; 95% CI, 0.34-0.58; P < .001) or any target limb reinterventions (MR, 0.67; 95% CI, 0.57-0.80; P < .001) per year was significantly less in the OPEN arm of cohort 1. The mean number of reinterventions per limb salvaged per year was lower in the OPEN arm of cohort 1 (MR, 0.45; 95% CI, 0.35-0.57; P < .001 and MR, 0.66; 95% CI, 0.55-0.79; P < .001 for major and all, respectively). The majority of index limb reinterventions occurred during the first year following randomization, but events continued to accumulate over the duration of follow-up in the trial. CONCLUSIONS: Reintervention is common following revascularization for chronic limb-threatening ischemia. Among patients deemed suitable for either approach, initial treatment with open bypass, particularly in patients with available SSGSV conduit, is associated with a significantly lower number of major and minor target limb reinterventions.

Long-term outcomes of autologous vein bypass for repair of upper and lower extremity major arterial trauma.

OBJECTIVE: Autologous vein is the preferred bypass conduit for extremity arterial injuries owing to superior patency and low infection risk; however, long-term data on outcomes in civilians are limited. Our goal was to assess short- and long-term outcomes of autologous vein bypass for upper and lower extremity arterial trauma. METHODS: A retrospective review was performed of patients with major extremity arterial injuries (2001-2019) at a level I trauma center. Demographics, injury and intervention details, and outcomes were recorded. Primary outcomes were primary patency at 1 year and 3 years. Secondary outcomes were limb function at 6 months, major amputation, and mortality. Multivariable analysis determined risk factors for functional impairment. RESULTS: There were 107 extremity arterial injuries (31.8% upper and 68.2% lower) treated with autologous vein bypass. Mechanism was penetrating in 77% of cases, of which 79.3% were due to firearms. The most frequently injured vessels were the common and superficial femoral (38%), popliteal (30%), and brachial arteries (29%). For upper extremity trauma, concomitant nerve and orthopedic injuries were found in 15 (44.1%) and 11 (32.4%) cases, respectively. For lower extremities, concomitant nerve injuries were found in 10 (13.7%) cases, and orthopedic injuries in 31 (42.5%). Great saphenous vein was the conduit in 96% of cases. Immediate intraoperative bypass revision occurred in 9.3% of patients, most commonly for graft thrombosis. The in-hospital return to operating room rate was 15.9%, with graft thrombosis (47.1%) and wound infections (23.5%) being the most common reasons. The median follow-up was 3.6 years. Kaplan-Meier analysis showed 92% primary patency at 1 year and 90% at 3 years. At 6 months, 36.1% of patients had functional impairment. Of patients with functional impairment at 6 months, 62.9% had concomitant nerve and 60% concomitant orthopedic injuries. Of those with nerve injury, 91.7% had functional impairment, compared with 17.8% without nerve injury (P < .001). Of patients with orthopedic injuries, 51.2% had functional impairment, vs 25% of those without orthopedic injuries (P = .01). On multivariable analysis, concomitant nerve injury (odds ratio, 127.4; 95% confidence interval, 17-957; P <. 001) and immediate intraoperative revision (odds ratio, 11.03; 95% confidence interval, 1.27-95.55; P = .029) were associated with functional impairment. CONCLUSIONS: Autologous vein bypass for major extremity arterial trauma is durable; however, many patients have long-term limb dysfunction associated with concomitant nerve injury and immediate intraoperative bypass revision. These factors may allow clinicians to identify patients at higher risk for functional impairment, to outline patient expectations and direct rehabilitation efforts toward improving functional outcomes.

Predictors of amputation-free survival and wound healing after infrainguinal bypass with alternative conduits.

OBJECTIVE: Inadequate vein quality or prior harvest precludes use of autologous single segment greater saphenous vein (ssGSV) in many patients with chronic limb-threatening ischemia (CLTI). Predictors of patient outcome after infrainguinal bypass with alternative (non-ssGSV) conduits are not well-understood. We explored whether limb presentation, bypass target, and conduit type were associated with amputation-free survival (AFS) after infrainguinal bypass using alternative conduits. METHODS: A single-center retrospective study (2013-2020) was conducted of 139 infrainguinal bypasses performed for CLTI with cryopreserved ssGSV (cryovein) (n = 71), polytetrafluoroethylene (PTFE) (n = 23), or arm/spliced vein grafts (n = 45). Characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, and outcomes were recorded. Multivariable Cox proportional hazards and classification and regression tree analysis modeled predictors of AFS. RESULTS: Within 139 cases, the mean age was 71 years, 59% of patients were male, and 51% of cases were nonelective. More patients undergoing bypass with cryovein were WIfI stage 4 (41%) compared with PTFE (13%) or arm/spliced vein (27%) (P = .04). Across groups, AFS at 2 years was 78% for spliced/arm, 79% for PTFE, and 53% for cryovein (adjusted hazard ratio for cryovein, 2.5; P = .02). Among cases using cryovein, classification and regression tree analysis showed that WIfI stage 3 or 4, age >70 years, and prior failed bypass were predictive of the lowest AFS at 2 years of 36% vs AFS of 58% to 76% among subgroups with less than two of these factors. Although secondary patency at 2 years was worse in the cryovein group (26% vs 68% and 89% in arm/spliced and PTFE groups; P < .01), in patients with tissue loss there was no statistically significant difference in wound healing in the cryovein group (72%) compared with other bypass types (72% vs 87%, respectively; P = .12). CONCLUSIONS: In patients with CLTI lacking suitable ssGSV, bypass with autogenous arm/spliced vein or PTFE has superior AFS compared with cryovein, although data were limited for PTFE conduits for distal targets. Despite poor patency with cryovein, wound healing is achieved in a majority of cases, although it should be used with caution in older patients with high WIfI stage and prior failed bypass, given the low rates of AFS.

Contemporary multimodal approach to diagnosis and treatment of vascular graft and endograft infections.

Vascular graft and endograft infections (VGEIs) are a feared complication because of their morbidity, cost, and mortality. Despite broad and varying strategies, as well as limited evidence, societal guidelines do exist. The objective of this review was to supplement current guidelines with emerging and multimodal techniques for treatment. An electronic search was performed using PubMed with specific search terms from 2019 to 2022 in which VGEIs were described or analyzed in the carotid, thoracic aorta, abdominal, or lower extremity arteries. A total of 12 studies were collected from the electronic search. Articles describing all of the anatomic areas were present. The incidence of VGEIs depends on the anatomic location, varying from <1% to 18%. Gram-positive bacteria are the most common organism. Referral of patients with VGEIs to centers of excellence is paramount, as is pathogen identification, preferably from direct sampling techniques. The MAGIC (Management of Aortic Graft Infection Collaboration) criteria have been endorsed for all VGEIs and validated for aortic VGEI. They are well supplemented with additional diagnostic techniques. Treatment must be individualized, although the goal should be the removal of infected material with appropriate revascularization. VGEIs remain a devastating complication, despite changing or improving medical surgical techniques in vascular surgery. Prophylactic measures, early diagnosis, and patient-specific therapy remain the cornerstones of treatment for this feared complication.

Preoperative Anemia is Associated with Poorer Postoperative Outcomes in Patients Undergoing Infrainguinal Bypass Surgery.

BACKGROUND: Preoperative anemia is an important, modifiable risk factor among surgical patients. However, data are scarce on the impact of preoperative anemia on postoperative outcomes after infrainguinal bypass. METHODS: In this multi-institutional analysis, data were retrospectively collected on all infrainguinal bypass procedures performed between 2010 and 2020. Patients were grouped by preoperative hemoglobin as per the National Cancer Institute anemia scale (mild, 10 g/dL-lower limit of normal; moderate, 8.0-9.9 g/dL; severe, 6.5-7.9 g/dL). Multivariable comparisons were performed using logistic regression analysis. RESULTS: A total of 492 patients underwent bypass for peripheral artery disease over the 10-year study period. Median preoperative hemoglobin was 11.0 g/dL (interquartile range 9.5-12.7) and median follow-up was 1.7 years. Preoperative anemia was prevalent among bypass patients (mild 52.4% [n = 258], moderate 26.4% [n = 130], and severe 5.1% [n = 25]). Women were more likely to have moderate (49.2% [women] vs. 50.8% [men]) or severe anemia (52.0% [women] vs. 48.0% [men]) compared with normal hemoglobin (17.7% [women] vs. 82.3% [men]) (P < 0.001). Patients with preoperative anemia were more likely to present with tissue loss (22.8% [normal] vs. 47.7% [moderate] vs. 52.0% [severe], P = 0.01). Bypass target and conduit types were similar between groups. Anemic patients had longer median hospital length of stay compared with nonanemic patients (4 days [normal] vs. 5 days [mild] vs. 6 days [moderate] vs. 7 days [severe], P < 0.001). Postoperative mortality at 30 days was similar across anemia groups (2.5% [normal] vs. 4.6% [moderate] vs. 8.0% [severe], P = 0.23). On multivariable analysis, however, postoperative mortality was independently associated with severe anemia (odds ratio 7.5 [1.2-48.8], P = 0.04) and male gender (odds ratio 7.5 [1.2-26.4], P = 0.03). CONCLUSIONS: Preoperative anemia is common among patients undergoing infrainguinal bypass surgery and is an independent risk factor for postoperative mortality. Future investigation is needed to determine whether correction of anemia improves postoperative outcomes in these high-risk patients.

Nitric oxide improves regeneration and prevents calcification in bio-hybrid vascular grafts via regulation of vascular stem/progenitor cells.

Vascular bypass surgery continues to use autologous grafts and often suffers from a shortage of donor grafts. Decellularized xenografts derived from porcine veins provide a promising candidate because of their abundant availability and low immunogenicity. Unfortunately, transplantation outcomes are far from satisfactory because of insufficient regeneration and adverse pathologic remodeling. Herein, a nitrate-functionalized prosthesis has been incorporated into a decellularized porcine vein graft to fabricate a bio-hybrid vascular graft with local delivery of nitric oxide (NO). Exogenous NO efficiently promotes vascular regeneration and attenuates intimal hyperplasia and vascular calcification in both rabbit and mouse models. The underlying mechanism was investigated using a Sca1 2A-CreER; Rosa-RFP genetic-lineage-tracing mouse model that reveals that Sca1+ stem/progenitor cells (SPCs) are major contributors to vascular regeneration and remodeling, and NO plays a critical role in regulating SPC fate. These results support the translational potential of this off-the-shelf vascular graft.

Clinical Effect of Revascularization Strategies and Pharmacologic Treatment on Long-Term Results in Patients with Advanced Peripheral Artery Disease with TASC C and D Femoropopliteal Lesions.

Background: This study was to assess the clinical outcome and associated parameters of endovascular therapy (EVT group) and bypass surgery (bypass group) in patients with long femoropopliteal TransAtlantic Inter-Society Consensus II (TASC II) C and D peripheral artery disease (PAD). Methods: 187 patients who underwent successful EVT or bypass surgery were assessed. The endpoints included the events of cardiovascular disease (CVD) and lower-extremity amputation (LEA), 3-year primary patency, and 3-year amputation-free survival (AFS). Results: The 3-year primary and secondary patency rates were better in the bypass group (P=0.007 and P=0.039, respectively), while the incidences of LEA, new CVD events, and mortality were comparable between groups. Weighted multivariate Cox analyses showed that cilostazol treatment (hazard ratio (HR): 0.46, 95% confidence interval (CI): 0.3-0.72, P=0.001), statin treatment (HR: 0.54, 95% CI: 0.33-0.9, P=0.014), and direct revascularization (DR) (HR: 0.47, 95% CI: 0.29-0.74, P=0.001) were predictive factors of 3-year primary patency. Kaplan-Meier curve analyses of time-to-primary cumulative AFS showed that nondiabetes mellitus, mild PAD, and cilostazol and statin treatment were correlated with a superior 3-year AFS (log rank test, P=0.001, P < 0.001, P=0.009, and P=0.044, respectively). Conclusions: Endovascular stenting based on the angiosome concept and bypass surgery provide comparable benefits for the treatment of long, advanced femoropopliteal lesions after a short follow-up period, whereas cilostazol therapy for more than 3 months, aggressive treatment of dyslipidemia, and surgical revascularization were associated with higher primary patency.

Systematic review of temporary intravascular shunt use in military and civilian extremity trauma.

BACKGROUND: The use of temporary intravascular shunts (TIVS) in the setting of military and civilian trauma has grown in recent years, predominantly because of the mounting evidence of improved limb outcomes. We sought to characterize the use and outcomes of TIVS in trauma through a systematic review of military and civilian literature. METHODS: The MEDLINE, EBSCO, EMBASE, and Cochrane databases were searched for studies on TIVS use in military and civilian trauma settings published between January 2000 and March 2021. Reports lacking systematic data collection along with those with insufficient TIVS descriptive and outcome data were excluded. Data regarding the characteristics and outcomes of TIVS were assessed and collective syntheses of military and civilian data performed. RESULTS: Twenty-one reports were included, 14 from civilian trauma centers or databases and 7 from military field data or databases (total of 1,380 shunts in 1,280 patients). Sixteen were retrospective cohort studies, and four were prospective. Five studies had an unshunted comparison group. Shunts were predominantly used in the lower extremity and most commonly for damage control indications. Dwell times were infrequently reported and were not consistently linked to shunt thrombosis or other complications. Anticoagulation during shunting was sparsely reported and inconsistently applied. Shunted limbs had higher injury severity than unshunted limbs but similar salvage rates. CONCLUSION: Temporary intravascular shunts are effective for expeditious restoration of perfusion in severely injured limbs and likely contribute to limb salvage. There is a paucity of comparative TIVS data in the literature and no consistently applied reporting standards, so controversies regarding TIVS use remain. LEVEL OF EVIDENCE: Systematic Review, level IV.

Impact of Perioperative Blood Transfusion in Anemic Patients Undergoing Infra Inguinal Bypass.

OBJECTIVE: Patients who present with lower extremity ischemia are frequently anemic and the optimal transfusion threshold for this cohort remains controversial. We sought to evaluate the impact of blood transfusion on postoperative major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients. METHODS: All consecutive patients who underwent infra-inguinal bypass at our institution from 2011 to 2020 were included. Perioperative red blood cell transfusion was the primary exposure, and the primary outcome was MACE. Univariate and multivariable analyses were performed to assess the impact of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hgb) nadir: <7, 7-8, and >8 g/dL. RESULTS: Of the 287 patients reviewed for analysis, 146 (50.9%) had a perioperative transfusion (mean: 1.6 ± 3 units). Patients who received a transfusion had a mean nadir Hgb of 8.3 ± 1.0 g/dL, compared to 10.1 ± 1.7 g/dL without a transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = 0.009), lower Hgb nadir (P = 0.02), and higher blood loss (P = 0.003). On multivariate analysis, transfusion was independently associated with MACE for patients with a Hgb nadir >8 g/dL (OR: 3.09; P = 0.006), but not for patients with Hgb nadir 7-8 g/dL (OR: 0.818; P = 0.77). Additionally, patients with MACE had significantly longer length of hospital stay than for patients without (13 vs. 7.7 days, P = 0.001). CONCLUSIONS: For patients undergoing infra-inguinal bypass, receiving a red blood cell transfusion with a Hgb nadir >8 g/dL was associated with a 3-fold increase in MACE, with nearly twice the length of stay. For patients with a Hgb 7-8 g/dL, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusion for patients with Hgb nadir >7 g/dL and harm for Hgb >8 g/dL, however causation cannot be proven due to the retrospective nature of the study and randomized studies are needed to confirm or refute these findings.