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Background: The Society of Vascular Surgery Wound Ischemia foot Infection (WIfI) classification system for chronic limb-threatening ischemia was intended to predict 1-year major lower extremity amputation (LEA) risk and to identify which patients benefit most from revascularization. We aimed to identify which WIfI presentations benefited most from revascularization to explore whether a cluster analysis could identify a more data-driven WIfI score, and to quantify which component of the WIfI score was most strongly associated with 1-year LEA after revascularization., Methods: Composite multi-institutional nested cohort data from centers who previously validated WIfI were reviewed retrospectively. We collected each patient's WIfI component grades and whether LEA was performed. To examine the benefit of revascularization, the predicted LEA rates were subtracted from observed LEA rates. We used k-means cluster analysis to model predicted vs observed LEA rates after revascularization. Multivariable linear regression analysis was performed to quantify which WIfI score component(s) best predicted LEA., Results: Data from 10 centers, accumulated between 2005 and 2015 were collated (2878 limbs at risk; 314 LEAs performed). The subset of patients who underwent revascularization comprised the study base (1654 limbs; 169 LEAs). Of 64 potential WIfI grade combinations, 15 were never reported and were excluded from the analysis. By original WIfI stages, the observed LEA rate after revascularization was: stage 1, 10.8% (14/130); stage 2, 4.9% (5/103); stage 3, 5.1% (25/487); and stage 4, 13.4% (125/934). Based on the difference between predicted and observed LEA risk for those who underwent revascularization, the WIfI scores were placed into quartiles from greatest to no benefit of revascularization. Cluster analysis identified four clusters with the following 1-year LEA rates: cluster 1, 4.4% (46/1038); cluster 2, 14.8% (66/447); cluster 3, 28.1% (36/128); and cluster 4, 51.2% (21/41). The between sum of squares/total sum of squares was 93.9%. Multiple linear regression revealed the wound grade most strongly predicted LEA (F-value, 17.25; P < .001). Ischemia (F-value, 6.51; P = .001) and infection (F-value, 5.7; P = .003) were similarly associated with LEA risk. Interaction terms between each component of the WIfI score were not statistically significant., Conclusions: WIfI can identify which patients with chronic limb-threatening ischemia are most likely to benefit from revascularization and may provide improved prognostication, risk stratification, and equitable outcome assessments. After revascularization, wound severity is most strongly associated with LEA risk. Ischemic and infectious grades confer additive, but not synergistic, risk. Future cluster analyses comparing specific WIfI presentations treated with and without revascularization will be required to further refine WIfI., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Guideline Summary: Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative., (Copyright © 2019 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Objective: Accurate survival prediction critically influences decision-making in caring for patients with chronic limb-threatening ischemia (CLTI). The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial demonstrated that in patients who survived >2 years, there was a significant advantage to infrainguinal bypass compared with endovascular intervention, which increased with time. Validated survival models for patients with CLTI are lacking., Methods: The Vascular Quality Initiative was interrogated for patients who underwent infrainguinal bypass or endovascular intervention for CLTI (January 2003-February 2017). Cox survival models were generated using only preoperative variables. Survival at 30 days, 2 years, and 5 years was modeled separately. Patients were defined as low risk (30-day survival >97% and 2-year survival >70%), medium risk (30-day survival 95%-97% or 2-year survival 50%-70%), and high-risk (30-day survival <95% or 2-year survival <50%)., Results: Among 38,470 unique CLTI patients, 63% (n = 24,214) underwent endovascular intervention and 37% (n = 14,256) underwent infrainguinal bypass. Kaplan-Meier estimates of overall survival at 30 days, 2 years, and 5 years were 98%, 81%, and 69%, respectively. The proportion of patients in the low-, medium-, and high-risk groups was 84%, 10%, and 6.5%, respectively. Patients in the low-risk group were significantly less likely to undergo endovascular intervention compared with those in the high-risk group (low risk, 59% endovascular; high risk, 75% endovascular; P < .0001). Independent predictors of death were similar in all three models, with greatest magnitude of effect associated with age >80 years, oxygen-dependent chronic obstructive pulmonary disease, stage 5 chronic kidney disease, and bedbound status. The C index for the 30-day model, 2-year model, and 5-year model was 0.76, 0.72, and 0.71, respectively. Procedure type (open or endovascular) was not significant in any models and did not have an impact on C indices., Conclusions: These survival prediction models, derived from a large U.S. cohort of patients who underwent revascularization for CLTI, demonstrated good performance and should be validated. Most CLTI patients considered candidates for limb salvage were of average perioperative risk and were predicted to survive beyond 2 years. These models can differentiate patients into low-, medium-, and high-risk groups to facilitate evidence-based revascularization recommendations that are consistent with current treatment guidelines., (Copyright © 2019 European Society for Vascular Surgery. All rights reserved.)

Objective: Peripheral atherectomy has been shown to have technical success in single-arm studies, but clinical advantages over angioplasty and stenting have not been demonstrated, leaving its role unclear. We sought to describe patterns of atherectomy use in a real-world U.S. cohort to understand how it is currently being applied., Methods: The Vascular Quality Initiative was queried to identify all patients who underwent peripheral vascular intervention from January 2010 to September 2016. Descriptive statistics were performed to analyze demographics of the patients, comorbidities, indication, treatment modalities, and lesion characteristics. The intermittent claudication (IC) and critical limb ischemia (CLI) cohorts were analyzed separately., Results: Of 85,605 limbs treated, treatment indication was IC in 51% (n = 43,506) and CLI in 49% (n = 42,099). Atherectomy was used in 15% (n = 13,092) of cases, equivalently for IC (15%; n = 6674) and CLI (15%; n = 6418). There was regional variation in use of atherectomy, ranging from a low of 0% in one region to a high of 32% in another region. During the study period, there was a significant increase in the proportion of cases that used atherectomy (11% in 2010 vs 18% in 2016; P < .0001). Compared with nonatherectomy cases, those with atherectomy use had higher incidence of prior peripheral vascular intervention (IC, 55% vs 43% [P < .0001]; CLI, 47% vs 41% [P < .0001]), greater mean number of arteries treated (IC, 1.8 vs 1.6 [P < .0001]; CLI, 2.1 vs 1.7 [P < .0001]), and lower proportion of prior leg bypass (IC, 10% vs 14% [P < .0001]; CLI, 11% vs 17% [P < .0001]). There was lower incidence of failure to cross the lesion (IC, 1% vs 4% [P < .0001]; CLI, 4% vs 7% [P < .0001]) but higher incidence of distal embolization (IC, 1.9% vs 0.8% [P < .0001]; CLI, 3.0% vs 1.4% [P < .0001]) and, in the CLI cohort, arterial perforation (1.4% vs 1.0%; P = .01)., Conclusions: Despite a lack of evidence for atherectomy over angioplasty and stenting, its use has increased across the United States from 2010 to 2016. It is applied equally to IC and CLI populations, with no identifiable pattern of comorbidities or lesion characteristics, suggesting that indications are not clearly delineated or agreed on. This study places impetus on further understanding of the optimal role for atherectomy and its long-term clinical benefit in the management of peripheral arterial disease., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The Society for Vascular Surgery Wound, Ischemia, foot Infection (WIfI) system aims to stratify threatened limbs according to their anticipated natural history and estimate the likelihood of benefit from revascularization, but whether it accurately stratifies outcomes in limbs undergoing aggressive treatment for limb salvage is unknown. We investigated whether the WIfI stage correlated with the intensity of limb treatment required and patient-centered outcomes., Methods: We stratified limbs from a prospectively maintained database of consecutive patients referred to a limb preservation center according to WIfI stage (October 2013-May 2015). Comorbidities, multimodal limb treatment, including foot operations and revascularization, and patient-centered outcomes (wound healing, limb salvage, amputation-free survival, maintenance of ambulatory and independent living status, and mortality) were compared among WIfI stages. Multivariate analysis was performed to identify predictors of wound healing and limb salvage., Results: We identified 280 threatened limbs encompassing all WIfI stages in 257 consecutive patients: stage 1, 48 (17%); stage 2, 67 (24%); stage 3, 64 (23%); stage 4, 83 (30%); and stage 5 (unsalvageable), 18 (6%). Operative foot débridement, minor amputation, and use of revascularization increased with increasing WIfI stage (P ≤ .04). Revascularization was performed in 106 limbs (39%), with equal use of open and endovascular procedures. Over a median follow-up of 209 days (interquartile range, 95, 340) days, 1-year Kaplan-Meier wound healing cumulative incidence was 71%, and the proportion with complete wound healing decreased with increasing WIfI stage. Major amputation was required in 26 stage 1 to 4 limbs (10%). Increasing WIfI stage was associated with decreased 1-year Kaplan-Meier limb salvage (stage 1: 96%, stage 2: 84%, stage 3: 90%, and stage 4: 78%; P = .003) and amputation-free survival (P = .006). Stage 4 WIfI independently predicted amputation (hazard ratio, 12; 95% confidence interval, 1.6-94). Amputation rates in patients with severe Ischemia grade 3 were lower in those who underwent revascularization than in those who did not (14% vs 41%; P = .01) Ambulatory and independent living status at follow-up deteriorated significantly from baseline in stage 4 but not stage 1 to 3 patients. Mortality was not different between WIfI stages., Conclusions: In patients treated aggressively for limb salvage, WIfI stage correlated with intensity of multimodal limb treatment and with limb salvage and patient-centered outcomes at 1 year. Revascularization improved limb salvage in severe ischemia. These data support the Society for Vascular Surgery WIfI system as a powerful tool to risk-stratify patients with threatened limbs and guide treatment., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Our objective was to analyze periprocedural and 1-year outcomes of peripheral endovascular intervention (PVI) for critical limb ischemia (CLI)., Methods: We reviewed 1244 patients undergoing 1414 PVIs for CLI (rest pain, 29%; tissue loss, 71%) within the Vascular Study Group of New England (VSGNE) from January 2010 to December 2011. Overall survival (OS), amputation-free survival (AFS), and freedom from major amputation at 1 year were analyzed using the Kaplan-Meier method. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs)., Results: The number of arteries treated during each procedure were 1 (49%), 2 (35%), 3 (12%), and ≥4 (5%). Target arterial segments and TransAtlantic Inter-Society Consensus classifications were aortoiliac, 27% (A, 48%; B, 28%; C, 12%; and D, 12%); femoral-popliteal, 48% (A, 29%; B, 34%; C, 20%; and D, 17%); and infrapopliteal, 25% (A, 17%; B, 14%; C, 25%; D, 44%). Technical success was 92%. Complications included access site hematoma (5.0%), occlusion (0.3%), and distal embolization (2.4%). Mortality and major amputation rates were 2.8% and 2.2% at 30 days, respectively. Overall percutaneous or open reintervention rate was 8.0% during the first year. At 1-year, OS, AFS, and freedom from major amputation were 87%, 87%, and 94% for patients with rest pain and 80%, 71%, and 81% for patients with tissue loss. Independent predictors of reduced 1-year OS (C index = .74) included dialysis (HR, 3.8; 95% CI, 2.8-5.1; P < .01), emergency procedure (HR, 2.5; 95% CI, 1.0-6.2; P = .05), age >80 years (HR, 2.2; 95% CI, 1.7-2.8; P < .01), not living at home preoperatively (HR, 2.0; 95% CI, 1.4-2.8; P < .01), creatinine >1.8 mg/dL (HR, 1.9; 95% CI, 1.3-2.8; P < .01), congestive heart failure (HR, 1.7; 95% CI, 1.3-2.2; P < .01), and chronic β-blocker use (HR, 1.4; 95% CI, 1.0-1.9; P = .03), whereas independent preoperative ambulation (HR, 0.7; 95% CI, 0.6-0.9; P = .014) was protective. Independent predictors of major amputation (C index = .69) at 1 year included dialysis (HR, 2.7; 95% CI, 1.6-4.5; P < .01), tissue loss (HR, 2.0; 95% CI, 1.1-3.7; P = .02), prior major contralateral amputation (HR, 2.0; 95% CI, 1.1-3.5; P = .02), non-Caucasian race (HR, 1.7; 95% CI, 1.0-2.9; P = .045), and male gender (HR, 1.6; 95% CI, 1.1-2.6; P = .03), whereas smoking (HR, .60; 95% CI, 0.4-1.0; P = .042) was protective., Conclusions: Survival and major amputation after PVI for CLI are associated with different patient characteristics. Dialysis dependence is a common predictor that portends especially poor outcomes. These data may facilitate efforts to improve patient selection and, after further validation, enable risk-adjusted outcome reporting for CLI patients undergoing PVI., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Although statin therapy has been linked to fewer short-term complications after infrainguinal bypass, its effect on long-term survival remains unclear. We therefore examined associations between statin use and long-term mortality, graft occlusion, and amputation after infrainguinal bypass., Methods: We used the Vascular Study Group of New England registry to study 2067 patients (71% male; mean age, 67 ± 11 years; 67% with critical limb ischemia [CLI]) who underwent infrainguinal bypass from 2003 to 2011. Of these, 1537 (74%) were on statins perioperatively and at 1-year follow-up, and 530 received no statin. We examined crude, adjusted, and propensity-matched rates of 5-year surviva1, 1-year amputation, graft occlusion, and perioperative myocardial infarction., Results: Patients taking statins at the time of surgery and at the 1-year follow-up were more likely to have coronary disease (38% vs 22%; P < .001), diabetes (51% vs 36%; P < .001), hypertension (89% vs 77%; P < .001), and prior revascularization procedures (50% vs 38%; P < .001). Despite higher comorbidity burdens, long-term survival was better for patients taking statins in crude (risk ratio [RR], 0.7; P < .001), adjusted (hazard ratio, 0.7; P = .001), and propensity-matched analyses (hazard ratio, 0.7; P = .03). In subgroup analysis, a survival advantage was evident in patients on statins with CLI (5-year survival rate, 63% vs 54%; log-rank, P = .01) but not claudication (5-year survival rate, 84% vs 80%; log-rank, P = .59). Statin therapy was not associated with 1-year rates of major amputation (12% vs 11%; P = .84) or graft occlusion (20% vs 18%; P = .58) in CLI patients. Perioperative myocardial infarction occurred more frequently in patients on a statin in crude analysis (RR, 2.2; P = .01) but not in the matched cohort (RR, 1.9; P = .17)., Conclusions: Statin therapy is associated with a 5-year survival benefit after infrainguinal bypass in patients with CLI. However, 1-year limb-related outcomes were not influenced by statin use in our large observational cohort of patients undergoing revascularization in New England., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Our aim was to evaluate the effect of gender on early and late procedural and functional outcomes of lower extremity bypass (LEB)., Methods: We reviewed the records of 2576 patients (828 women; 32%) who underwent LEB for claudication or critical limb ischemia (CLI) in the Vascular Study Group of New England from 2003 to 2010. Logistic regression and proportional hazards models were used to adjust for potential confounding differences between genders. Morbidity, mortality, graft patency, freedom from major amputation, ambulation, and living status were analyzed postoperatively and over 1 year., Results: Women were older (70 vs 68 years; P < .001), had more hypertension (89% vs 85%; P = .006), less coronary artery disease (35% vs 39%; P = .03), smoking (73% vs 88%; P < .001), and preoperative statin use (60% vs 64%; P = .04). Women were more likely to have CLI (76% vs 71%; P = .003), and ambulate with assistance at presentation (19% vs 16%; P = .02). Morbidity was similar except women had higher rates of reoperation for thrombosis (4% vs 2%; P < .001) without differences in major amputation (2% vs 1%; P = .13) or in-hospital mortality (1.7% vs 1.7%; P = .96). Women and men with claudication had similar 1-year graft patency rates. Women with CLI had lower rates of primary (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.03-1.48; P = .02), assisted primary (HR, 1.42; 95% CI, 1.15-1.76; P = .001) and secondary patency (HR, 1.40; 95% CI, 1.10-1.77; P = .006) during the first year compared with men. Freedom from amputation was similar for men and women with CLI (HR, 1.17; 95% CI, 0.84-1.63; P = .36). There were no differences in late survival between women and men with claudication (HR, 0.89; 95% CI, 0.60-1.31; P = .36) or CLI (HR, 0.94; 95% CI, 0.81-1.09; P = .39). More female claudicants were not independently ambulatory at discharge (30% vs 19%; P = .002) and were discharged to a nursing home (15% vs 5%; P < .001) but these differences did not persist at 1 year. Women with CLI were more likely to be nonambulatory at discharge (13% vs 9%; P = .006) and at 1 year (13% vs 8%; P < .001). More women with CLI were discharged to a nursing home (44% vs 35%; P = .01) and resided there at 1 year (11% vs 7%; P = .02)., Conclusions: Women have complication rates similar to men with inferior early and late functional outcomes after LEB. The reduced patency rates in women with CLI did not translate into differences in limb salvage. These findings might help define physician and patient expectations for women before revascularization., (Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Significant variability exists in completion imaging (CIM) after infrainguinal lower extremity bypass (LEB). We evaluated the use of CIM and compared graft patency in patients treated by surgeons who performed routine CIM vs those who performed selective CIM., Methods: We reviewed the Vascular Study Group of New England database (2003-2010) and assessed the use of CIM (angiography or duplex ultrasound) among patients undergoing LEB. The surgeon-specific CIM strategy was categorized as routine (≥80% of LEBs) vs selective (<80% of LEBs). Exclusion criteria included acute limb ischemia, bilateral procedures, and surgeon volume <10 cases per study period. Primary graft patency at discharge and at 1 year was analyzed on the basis of CIM use and surgeon-specific CIM strategy. Multivariable analyses were performed using Poisson regression., Results: Among 2032 LEB procedures performed by 48 surgeons, CIM was used in 1368 cases (67.3%). CIM was performed in 72% of autogenous LEBs and 52% of prosthetic grafts. Dialysis (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6; P = .01), elective LEB (OR, 2.6; 95% CI, 1.4-4.8; P = .002), great saphenous vein conduit (OR, 2.0; 95% CI, 1.6-2.5; P < .001), and tibial or pedal target artery (OR, 1.8; 95% CI, 1.4-2.3; P < .001) were associated with CIM use. In multivariate models, CIM was not associated with improved primary graft patency at discharge (OR, 1.1; 95% CI, 0.7-1.7; P = .64) or at 1 year (OR, 0.9; 95% CI, 0.7-1.2; P = .47). Sixteen surgeons (33%) were routine users and 32 (67%) were selective users of CIM. Among patients of routine vs selective CIM users, primary graft patency at discharge and at 1 year was 96% vs 94% (P = .21) and 68% vs 72% (P = .09), respectively. In multivariate analysis, routine or selective CIM strategy was not associated with improved discharge (rate ratio, 0.8; 95% CI, 0.6-1.1; P = .31) or 1-year (rate ratio, 1.1; 95% CI, 0.9-1.2; P = .56) graft patency., Conclusions: In our observational cohort, CIM does not improve short-term and 1-year bypass graft patency in infrainguinal LEB. The surgeon-specific strategy of selective CIM after LEB has outcomes comparable to those of routine CIM., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Critical limb ischemia, first defined in 1982, was intended to delineate a subgroup of patients with a threatened lower extremity primarily because of chronic ischemia. It was the intent of the original authors that patients with diabetes be excluded or analyzed separately. The Fontaine and Rutherford Systems have been used to classify risk of amputation and likelihood of benefit from revascularization by subcategorizing patients into two groups: ischemic rest pain and tissue loss. Due to demographic shifts over the last 40 years, especially a dramatic rise in the incidence of diabetes mellitus and rapidly expanding techniques of revascularization, it has become increasingly difficult to perform meaningful outcomes analysis for patients with threatened limbs using these existing classification systems. Particularly in patients with diabetes, limb threat is part of a broad disease spectrum. Perfusion is only one determinant of outcome; wound extent and the presence and severity of infection also greatly impact the threat to a limb. Therefore, the Society for Vascular Surgery Lower Extremity Guidelines Committee undertook the task of creating a new classification of the threatened lower extremity that reflects these important considerations. We term this new framework, the Society for Vascular Surgery Lower Extremity Threatened Limb Classification System. Risk stratification is based on three major factors that impact amputation risk and clinical management: Wound, Ischemia, and foot Infection (WIfI). The implementation of this classification system is intended to permit more meaningful analysis of outcomes for various forms of therapy in this challenging, but heterogeneous population., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: The autogenous vein is the preferred conduit in below-knee vascular reconstructions. However, many argue that prosthetic grafts can perform well in crural bypass with adjunctive antithrombotic therapy. We therefore compared outcomes of below-knee prosthetic versus autologous vein bypass grafts for critical limb ischemia and the use of adjunctive antithrombotic therapy in both settings., Methods: Utilizing the registry of the Vascular Study Group of New England (2003-2009), we studied 1227 patients who underwent below-knee bypass for critical limb ischemia, 223 of whom received a prosthetic graft to the below-knee popliteal artery (70%) or more distal target (30%). We used propensity matching to identify a patient cohort receiving single-segment saphenous vein yet had remained similar to the prosthetic cohort in terms of characteristics, graft origin/target, and antithrombotic regimen. Main outcome measures were graft patency and major limb amputation within 1 year. Secondary outcomes were bleeding complications (reoperation or transfusion) and mortality. We performed comparisons by conduit type and by antithrombotic therapy., Results: Patients receiving prosthetic conduit were more likely to be treated with warfarin than those with greater saphenous vein (57% vs. 24%, P<0.001). After propensity score matching, we found no significant difference in primary graft patency (72% vs. 73%, P=0.81) or major amputation rates (17% vs. 13%, P=0.31) between prosthetic and single-segment saphenous vein grafts. In a subanalysis of grafts to tibial versus popliteal targets, we noted equivalent primary patency and amputation rates between prosthetic and venous conduits. Whereas overall 1-year prosthetic graft patency rates varied from 51% (aspirin+clopidogrel) to 78% (aspirin+warfarin), no significant differences were seen in primary patency or major amputation rates by antithrombotic therapy (P=0.32 and 0.17, respectively). Further, the incidence of bleeding complications and 1-year mortality did not differ by conduit type or antithrombotic regimen in the propensity-matched analysis., Conclusions: Although limited in size, our study demonstrates that, with appropriate patient selection and antithrombotic therapy, 1-year outcomes for below-knee prosthetic bypass grafting can be comparable to those for greater saphenous vein conduit., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia., Methods: All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year., Results: Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function, and respiratory complications. Patients who underwent lower extremity bypass for acute limb ischemia had no difference in rates of graft occlusion (18.1% vs 18.5%; P = .77), but did have significantly higher rates of limb loss (22.4% vs 9.7%; P < .0001) and mortality (20.9% vs 13.1%; P < .0001) at 1 year. On multivariable analysis, acute limb ischemia was an independent predictor of both major amputation (hazard ratio, 2.16; confidence interval, 1.38-3.40; P = .001) and mortality (hazard ratio, 1.41; confidence interval, 1.09-1.83; P = .009) at 1 year., Conclusions: Patients who present with acute limb ischemia represent a less medically optimized subgroup within the population of patients undergoing lower extremity bypass. These patients may be expected to have more complex operations followed by increased rates of perioperative adverse events. Additionally, despite equivalent graft patency rates, patients undergoing lower extremity bypass for acute ischemia have significantly higher rates of major amputation and mortality at 1 year., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Introduction: To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb., Methods: A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year., Results: Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38% vs 17%; P < .0001) and major amputation (16% vs 7%; P < .0001) at 1 year, there was not a significant difference in mortality (16% vs 10%; P = .160). On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06-2.83; P = .027) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39-2.68; P < .0001) at 1 year., Conclusions: Patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population, even among patients with advanced peripheral arterial disease. When considering LEB in this setting, both physicians and patients should expect increased rates of perioperative adverse events, increased rates of 1-year graft occlusion, and decreased rates of limb salvage, when compared with patients who have not undergone a contralateral amputation., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: The appropriate application of endovascular intervention vs bypass for both critical limb ischemia (CLI) and intermittent claudication (IC) remains controversial, and outcomes from large, contemporary series are critical to help inform treatment decisions. Therefore, we sought to define the early and 1-year outcomes of lower extremity bypass (LEB) in a large, multicenter regional cohort, and analyze trends in the use of LEB with or without prior endovascular interventions., Methods: The Vascular Study Group of New England database was used to identify all infrainguinal LEB procedures performed between 2003 and 2009. The primary study endpoint was 1-year amputation-free survival (AFS). Secondary endpoints included in-hospital mortality and morbidity, including major adverse cardiac events. Trend analyses were conducted to identify annual trends in the proportion of LEBs performed for an indication of IC, in-hospital outcomes, including mortality and morbidity, and 1-year outcomes, including AFS. Analyses were performed on the entire cohort and then stratified by indication., Results: Between 2003 and 2009, 2907 patients were identified who underwent LEBs (72% for CLI; 28% for IC). The proportion that underwent LEB for IC increased significantly over the study period (from 19% to 31%; P < .0001). There was a significant increase over time in the proportion of LEBs performed after a previous endovascular intervention among both CLIs (from 11% to 24%; P < .0001) and ICs (from 13% to 23%; P = .02). Neither in-hospital mortality nor cardiac event rates changed significantly among either group. There was no significant change in 1-year AFS in patients with IC (97% in 2003 and 98% in 2008; P for trend .63) or in patients with CLI (73% in 2003 and 81% in 2008; P = .10)., Conclusions: Over the last 7 years, significant changes in patient selection for LEBs have occurred in New England. The proportion of LEBs performed for ICs as opposed to CLIs has increased. Patients are much more likely to have undergone prior endovascular interventions before undergoing a bypass. In-hospital and 1-year outcomes after LEB for both IC and CLI have remained excellent with no significant changes in AFS., (Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: Some patients who undergo lower extremity bypass (LEB) for critical limb ischemia ultimately require amputation. The functional outcome achieved by these patients after amputation is not well known. Therefore, we sought to characterize the functional outcome of patients who undergo amputation after LEB, and to describe the pre- and perioperative factors associated with independent ambulation at home after lower extremity amputation., Methods: Within a cohort of 3,198 patients who underwent an LEB between January, 2003 and December, 2008, we studied 436 patients who subsequently received an above-knee (AK), below-knee (BK), or minor (forefoot or toe) ipsilateral or contralateral amputation. Our main outcome measure consisted of a "good functional outcome," defined as living at home and ambulating independently. We calculated univariate and multivariate associations among patient characteristics and our main outcome measure, as well as overall survival., Results: Of the 436 patients who underwent amputation within the first year following LEB, 224 of 436 (51.4%) had a minor amputation, 105 of 436 (24.1%) had a BK amputation, and 107 of 436 (24.5%) had an AK amputation. The majority of AK (75 of 107, 72.8%) and BK amputations (72 of 105, 70.6%) occurred in the setting of bypass graft thrombosis, whereas nearly all minor amputations (200 of 224, 89.7%) occurred with a patent bypass graft. By life-table analysis at 1 year, we found that the proportion of surviving patients with a good functional outcome varied by the presence and extent of amputation (proportion surviving with good functional outcome = 88% no amputation, 81% minor amputation, 55% BK amputation, and 45% AK amputation, p = 0.001). Among those analyzed at long-term follow-up, survival was slightly lower for those who had a minor amputation when compared with those who did not receive an amputation after LEB (81 vs. 88%, p = 0.02). Survival among major amputation patients did not significantly differ compared with no amputation (BK amputation 87%, p = 0.14, AK amputation 89%, p = 0.27); however, this part of the analysis was limited by its sample size (n = 212). In multivariable analysis, we found that the patients most likely to remain ambulatory and live independently despite undergoing a lower extremity amputation were those living at home preoperatively (hazard ratio [HR]: 6.8, 95% confidence interval [CI]: 0.94-49, p = 0.058) and those with preoperative statin use (HR: 1.6, 95% CI: 1.2-2.1, p = 0.003), whereas the presence of several comorbidities identified patients less likely to achieve a good functional outcome: coronary disease (HR: 0.6, 95% CI: 0.5-0.9, p = 0.003), dialysis (HR: 0.5, 95% CI: 0.3-0.9, p = 0.02), and congestive heart failure (HR: 0.5, 95% CI: 0.3-0.8, p = 0.005)., Conclusions: A postoperative amputation at any level impacts functional outcomes following LEB surgery, and the extent of amputation is directly related to the effect on functional outcome. It is possible, based on preoperative patient characteristics, to identify patients undergoing LEB who are most or least likely to achieve good functional outcomes even if a major amputation is ultimately required. These findings may assist in patient education and surgical decision making in patients who are poor candidates for lower extremity bypass., (Published by Elsevier Inc.)

Background: Although open surgical bypass remains the standard revascularization strategy for patients with critical limb ischemia (CLI), many centers now perform peripheral endovascular intervention (PVI) as the first-line treatment for these patients. We sought to determine the effect of a prior ipsilateral PVI (iPVI) on the outcome of subsequent lower extremity bypass (LEB) in patients with CLI., Methods: A retrospective cohort analysis of all patients undergoing infrainguinal LEB between 2003 and 2009 within hospitals comprising the Vascular Study Group of New England (VSGNE) was performed. Primary study endpoints were major amputation and graft occlusion at 1 year postoperatively. Secondary outcomes included in-hospital major adverse events (MAE), 1-year mortality, and composite 1-year major adverse limb events (MALE). Event rates were determined using life table analyses and comparisons were performed using the log-rank test. Multivariate predictors were determined using a Cox proportional hazards model with multilevel hierarchical adjustment., Results: Of 1880 LEBs performed, 32% (n = 603) had a prior infrainguinal revascularization procedure (iPVI, 7%; ipsilateral bypass, 15%; contralateral PVI, 3%; contralateral bypass, 17%). Patients with prior iPVI, compared with those without a prior iPVI, were more likely to be women (32 vs 41%; P = .04), less likely to have tissue loss (52% vs 63%; P = .02), more likely to require arm vein conduit (16% vs 5%; P = .001), and more likely to be on statin (71% vs 54%; P = .01) and beta blocker therapy (92% vs 81%; P = .01) at the time of their bypass procedure. Other demographic factors were similar between these groups. Prior PVI or bypass did not alter 30-day MAE and 1-year mortality after the index bypass. In contrast, 1-year major amputation and 1-year graft occlusion rates were significantly higher in patients who had prior iPVI than those without (31% vs 20%; P = .046 and 28% vs 18%; P = .009), similar to patients who had a prior ipsilateral bypass (1 year major amputation, 29% vs 20%; P = .022; 1 year graft occlusion, 33% vs 18%; P = .001). Independent multivariate predictors of higher 1-year amputation and graft occlusion rates were prior iPVI, prior ipsilateral bypass, dialysis dependence, prosthetic conduit and distal (tibial and pedal) bypass target., Conclusions: Prior iPVI is highly predictive for poor outcome in patients undergoing LEB for CLI with higher 1-year amputation and graft occlusion rates than those without prior revascularization, similar to prior ipsilateral bypass These findings provide information, which may help with the complex decisions surrounding revascularization options in patients with CLI., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Background: To develop standardized metrics for expected outcomes in lower extremity revascularization for critical limb ischemia (CLI), the Society for Vascular Surgery (SVS) has developed objective performance goals (OPGs) based on aggregate data from randomized trials of lower extremity bypass (LEB). It remains unknown, however, if these targets can be achieved in everyday vascular surgery practice., Methods: We applied SVS OPG criteria to 1039 patients undergoing 1039 LEB operations for CLI with autogenous vein (excluding patients on dialysis) within the Vascular Study Group of New England (VSGNE). Each of the individual OPGs was calculated within the VSGNE dataset, along with its surrounding 95% confidence intervals (CIs) and compared to published SVS OPGs using χ(2) comparisons and survival analysis., Results: Across most risk strata, patients in the VSGNE and SVS OPG cohorts were similar (clinical high-risk [age >80 years and tissue loss]: 15.3% VSGNE; 16.2% SVS OPG; P = .58; anatomic high risk [infrapopliteal target artery]: 57.8% VSGNE; 60.2% SVS OPG; P = .32). However, the proportion of VSGNE patients designated as conduit high-risk (lack of single-segment great saphenous vein) was lower (10.2% VSGNE; 26.9% SVS OPG;P < .001). The primary safety endpoint, major adverse limb events (MALE) at 30 days, was lower in the VSGNE cohort (3.2%; 95% CI, 2.3-4.6) than the SVS OPG cohort (6.2%; 95% CI, 4.2-8.1; P = .05). The primary efficacy OPG endpoint, freedom from any MALE or postoperative death within the first year (MALE + postoperative death [POD]), was similar between VSGNE and SVS OPG cohorts (77%; 95% CI, 74%-80%) SVS OPG, 74% (95% CI, 71%-77%) VSGNE, P = .58). In the remaining safety and efficacy OPGs, the VSGNE cohort met or exceeded the benchmarks established by the SVS OPG cohort., Conclusion: Community and academic centers in everyday vascular surgery practice can meet OPGs derived from centers of excellence in LEB. Quality improvement initiatives, as well as clinical trials, should incorporate OPGs in their outcome measures to facilitate communication and comparison of risk-adjusted outcomes in the treatment of CLI., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Studies of infrainguinal lower extremity bypass for critical limb ischemia (CLI) have traditionally emphasized outcomes of patency, limb salvage, and death. Because functional outcomes are equally important, our objectives were to describe the proportion of CLI patients who did not achieve symptomatic improvement 1 year after bypass, despite having patent grafts, and identify preoperative factors associated with this outcome., Methods: The prospectively collected Vascular Study Group of Northern New England database was used to identify all patients with elective infrainguinal lower extremity bypass for CLI (2003 to 2007) for whom long-term follow-up data were available. The primary composite study end point was clinical failure at 1 year after bypass, defined as amputation or persistent or worsened ischemic symptoms (rest pain or tissue loss), despite a patent graft. Variables identified on univariate screening (inclusion threshold, P < .20) were included in a multivariable logistic regression model to identify independent predictors., Results: Long-term follow-up data were available for 1012 patients who underwent infrainguinal bypasses for CLI, of which 788 (78%) remained patent at 1 year. Of these, 79 (10%) met criteria for the composite end point of clinical failure: 21 (2.7%) for major amputations and 58 (7.4%) for persistent rest pain or tissue loss. In multivariable analysis, significant predictors of clinical failure included dialysis dependence (odds ratio [OR], 3.74; 95% confidence interval [CI], 1.84-7.62; P < .001) and preoperative inability to ambulate independently (OR, 2.17; 95% CI, 1.26-3.73; P = .005). A history of coronary artery bypass graft or percutaneous coronary intervention was protective (OR, 0.52; 95% CI, 0.29-0.93; P = .03)., Conclusions: After infrainguinal lower extremity bypass for CLI, 10% of patients with a patent graft did not achieve clinical improvement at 1 year. Preoperative identification of this specific patient subgroup remains challenging. To improve surgical decision making and the overall care of CLI patients, further emphasis needs to be placed on functional outcomes in addition to traditional surgical end points., Competing Interests: Competition of interest: none. The editors and reviewers of this article have no relevant financial relationships to disclose per the JVS policy that requires reviewers to decline review of any manuscript for which they may have a competition of interest., (Copyright (c) 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Given both the high-risk nature of the critical limb ischemia (CLI) patient population, as well as the variety of available treatment options, the ability to use preprocedure variables to predict a given outcome has become increasingly important. The three main advantages associated with accurate risk stratification include: (1) improved clinical decision-making based on realistic patient and physician expectations, (2) ability to benchmark individual practitioners and institutions by comparing their outcomes with expected outcomes specific to the actual patients being treated, and (3) creation of objective performance goals for the evaluation of new treatment modalities in specific patient populations. Patients with CLI have multiple comorbidities that can impact greatly on the outcomes of attempted revascularization. The PREVENT III CLI Risk Score was developed as a tool to estimate amputation-free survival at 1 year in patients undergoing vein bypass surgery for limb salvage, and has now been validated using data from >3,000 cases. The score incorporates five baseline clinical variables-dialysis, tissue loss, age, hematocrit, and coronary artery disease-and assigns patients into three distinct risk groups. Patients in the high-risk subgroup (8.2% of total number of patients evaluated) experienced <50% amputation-free survival at 1 year. This tool may be valuable in assisting both the surgeon and patient faced with treatment decisions in CLI.

Objective: The PREVENT III (PIII) critical limb ischemia (CLI) risk score is a simple, published tool derived from the PIII randomized clinical trial that can be used for estimating amputation-free survival (AFS) in CLI patients considered for infrainguinal bypass (IB). The current study sought to validate this risk stratification model using data from the prospectively collected Vascular Study Group of Northern New England (VSGNNE)., Method: We calculated the PIII CLI risk score for 1166 patients undergoing IB with autogenous vein by 59 surgeons at 11 hospitals between January 1, 2003, and December 31, 2007. Points (pts) were assigned to each patient for the presence of dialysis (4 pts), tissue loss (3 pts), age >or=75 (2 pts), and coronary artery disease (CAD) (1 pt). Baseline hematocrit was not included due to a large proportion of missing values. Total scores were used to stratify each patient into low-risk (or=8 pts) categories. The Kaplan-Meier method was used to calculate AFS for the three risk groups. Log-rank test was used for intergroup comparisons. To assess validation, comparison to the PIII derivation and validation sets was performed., Result: Stratification of the VSGNNE patients by risk category yielded three significantly different estimates for 1-year AFS (86.4%, 74.0%, and 56.1%, for low-, med-, and high-risk groups). Intergroup comparison demonstrated precise discrimination (P < .0001). For a given risk category (low, med, or high), the 1-year AFS estimates in the VSGNNE dataset were consistent with those observed in the previously published PIII derivation set (85.9%, 73.0%, and 44.6%, respectively), PIII validation set (87.7%, 63.7%, and 45.0%, respectively), and retrospective multicenter validation set (86.3%, 70.1%, and 47.8%, respectively)., Conclusion: The PIII CLI risk score has now been both internally and externally validated by testing it against the outcomes of 3286 CLI patients who underwent autogenous vein bypass at 94 institutions by a diverse array of physicians (three independent cohorts of patients). This tool provides a simple and reliable method to risk stratify CLI patients being considered for IB. At initial consultation, calculation of the PIII CLI risk score can reliably stratify patients according to their risk of death or major amputation at 1 year.

Background: Patients with critical limb ischemia (CLI) are a heterogeneous population with respect to risk for mortality and limb loss, complicating clinical decision-making. Endovascular options, compared with bypass, offer a tradeoff between reduced procedural risk and inferior durability. Risk stratified data predictive of amputation-free survival (AFS) may improve clinical decision making and allow for better assessment of new technology in the CLI population., Methods: This was a retrospective analysis of prospectively collected data from patients who underwent infrainguinal vein bypass surgery for CLI. Two datasets were used: the PREVENT III randomized trial (n = 1404) and a multicenter registry (n = 716) from three distinct vascular centers (two academic, one community-based). The PREVENT III cohort was randomly assigned to a derivation set (n = 953) and to a validation set (n = 451). The primary endpoint was AFS. Predictors of AFS identified on univariate screen (inclusion threshold, P < .20) were included in a stepwise selection Cox model. The resulting five significant predictors were assigned an integer score to stratify patients into three risk groups. The prediction rule was internally validated in the PREVENT III validation set and externally validated in the multicenter cohort., Results: The estimated 1-year AFS in the derivation, internal validation, and external validation sets were 76.3%, 72.5%, and 77.0%, respectively. In the derivation set, dialysis (hazard ratio [HR] 2.81, P < .0001), tissue loss (HR 2.22, P =.0004), age >or=75 (HR 1.64, P = .001), hematocrit or=8 [8.8% of cohort]). Stratification of the patients, in each dataset, according to risk category yielded three significantly different Kaplan-Meier estimates for 1-year AFS (86%, 73%, and 45% for low, medium, and high risk groups, respectively). For a given risk category, the AFS estimate was consistent between the derivation and validation sets., Conclusion: Among patients selected to undergo surgical bypass for infrainguinal disease, this parsimonious risk stratification model reliably identified a category of CLI patients with a >50% chance of death or major amputation at 1 year. Calculation of a "PIII risk score" may be useful for surgical decision making and for clinical trial designs in the CLI population.

Background: The remodeling of vein bypass grafts after arterialization is incompletely understood. We have previously shown that significant outward lumen remodeling occurs during the first month of implantation, but the magnitude of this response is highly variable. We sought to examine the hypothesis that systemic inflammation influences this early remodeling response., Methods: A prospective observational study was done of 75 patients undergoing lower extremity bypass using autogenous vein. Graft remodeling was assessed using a combination of ultrasound imaging and two-dimensional high-resolution magnetic resonance imaging., Results: The vein graft lumen diameter change from 0 to 1 month (22.7% median increase) was positively correlated with initial shear stress (P = .016), but this shear-dependent response was disrupted in subjects with an elevated baseline high-sensitivity C-reactive protein (hsCRP) level of >5 mg/L. Despite similar vein diameter and shear stress at implantation, grafts in the elevated hsCRP group demonstrated less positive remodeling from 0 to 1 month (13.5% vs 40.9%, P = .0072). By regression analysis, the natural logarithm of hsCRP was inversely correlated with 0- to 1-month lumen diameter change (P = .018). Statin therapy (beta = 23.1, P = .037), hsCRP (beta = -29.7, P = .006), and initial shear stress (beta = .85, P = .003) were independently correlated with early vein graft remodeling. In contrast, wall thickness at 1 month was not different between hsCRP risk groups. Grafts in the high hsCRP group tended to be stiffer at 1 month, as reflected by a higher calculated elastic modulus (E = 50.4 vs 25.1 Mdynes/cm2, P = .07)., Conclusions: Early positive remodeling of vein grafts is a shear-dependent response that is modulated by systemic inflammation. These data suggest that baseline inflammation influences vein graft healing, and therefore, inflammation may be a relevant therapeutic target to improve early vein graft adaptation.

Objective: Evidence suggesting a beneficial effect of cardioprotective medications in patients with lower extremity atherosclerosis derives largely from secondary prevention studies of heterogeneous populations. Patients with critical limb ischemia (CLI) have a large atherosclerotic burden with related high mortality. The effect of such therapies in this population is largely inferred and unproven., Methods: The Project of Ex-Vivo vein graft Engineering via Transfection III (PREVENT III) cohort comprised 1404 patients with CLI who underwent lower extremity bypass grafting in a multicenter, randomized prospective trial testing the efficacy of edifoligide for the prevention of graft failure. Propensity scores were used to evaluate the influence of statins, beta-blockers, and antiplatelet agents on outcomes while adjusting for demographics, comorbidities, medications, and surgical variables that may influence drug use. Primary outcomes were major adverse cardiovascular events < or =30 days, vein graft patency, and 1-year survival assessed by Kaplan-Meier method. Potential determinants of 1-year survival were modeled using a multivariate Cox regression., Results: In this cohort, 636 patients (45%) were taking statins, 835 (59%) were taking beta-blockers, and 1121 (80%) were taking antiplatelet drugs. Perioperative major adverse cardiovascular events (7.8%) and early mortality (2.7%) were not measurably affected by the use of any drug class. Statin use was associated with a significant survival advantage at 1 year of 86% vs 81% (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.52-0.98; P = .03) by analysis of both unweighted and propensity score-weighted data. Use of beta-blockers and antiplatelet drugs had no appreciable impact on survival. None of the drug classes were associated with graft patency measures at 1 year. Significant predictors of 1-year mortality by Cox regression modeling were statin use (HR, 0.67; 95% CI, 0.51-0.90; P = .001), age >75 (HR, 2.1; 95% CI, 1.60-2.82; P = .001), coronary artery disease (HR, 1.5; 95% CI, 1.15-2.01; P = .001), chronic kidney disease stages 4 (HR, 2.0; 95% CI, 1.17-3.55; P = .001) and 5 (HR, 3.4; 95% CI, 2.39-4.73; P < .001), and tissue loss (HR, 1.9; 95% CI, 1.23-2.80; P = .003)., Conclusions: Statin use is associated with improved survival in CLI patients 1 year after surgical revascularization. Further studies are indicated to determine optimal dosing in this population and to definitively address the question of relationship to graft patency. These data add to the growing literature supporting statin use in patients with advanced peripheral arterial disease.

Objective: The influence of operator-dependent variables on the outcomes of lower extremity bypass (LEB) surgery have primarily been reported in single-institution, retrospective studies. We utilized data from a prospective, multicenter trial to identify technical variables that were significantly associated with early and midterm results of autogenous LEB for limb salvage., Methods: The PREVENT III trial database includes 1404 North American patients with critical limb ischemia (CLI) who underwent LEB using excised autogenous vein. The study protocol excluded claudicants and in situ reconstructions. Technical factors analyzed included vein diameter, conduit type, graft length, vein orientation, location of proximal and distal anastomoses, and performance of completion imaging. Univariate analysis was used to determine the effect of these factors on 30 day and 1-year outcomes. Multivariate Cox regression models evaluated the influence of these factors while adjusting for age, sex, race, tobacco, diabetes, dialysis-dependency, previous index limb bypass, and study drug (edifoligide) administration. The primary outcomes were primary patency (PP), primary assisted patency (PAP), and secondary patency (SP) assessed by Kaplan-Meier method., Results: Univariate analysis revealed that vein diameter <3.5 mm and composite graft type were significantly associated with early (30 day) graft failure. At 1 year, multivariate analysis revealed that patency rates were negatively associated with diameter <3.5 mm (PP, PAP, SP), non-great saphenous vein (GSV) type (PP, SP), and graft lengths >50 cm (PP only). Limb salvage and survival at 1 year were not significantly impacted by technical variables. Employing a prespecified trial definition of high-risk conduits (diameter <3mm or nonsingle segment GSV; 24% of entire cohort) revealed that use of such conduits was associated with a 2.1-fold increased risk of 30 day graft failure (P < .05), as well as reduced PP, PAP, and SP at 1 year. Use of a high-risk conduit was also associated with an increased index length of stay (mean 9.37 vs 8.71 days, P = .03) and a greater number of reinterventions (mean 0.67 vs 0.42, P < .0001) over the ensuing year., Conclusions: In this large, multicenter cohort of patients undergoing LEB for CLI, vein diameter and conduit type were the dominant technical determinants of early and late graft failure. High-risk conduits and longer grafts may benefit from aggressive postoperative graft surveillance.

Background: Iliac angioplasty in preparation for an infrainguinal bypass graft has been shown to be an effective strategy. We undertook this study to determine if superficial femoral artery (SFA) angioplasty offers durable inflow for distal origin grafts originating from the SFA or popliteal artery., Methods: All distal origin grafts performed at a single institution between 1988 and 2006,

Diagnosis of hand ischemia secondary to an arteriovenous (AV) hemodialysis access is predominantly based on clinical findings. Occasionally, this diagnosis is unclear and more objective diagnostic testing is needed. No validated method of objective testing currently exists. The purpose of this study is to evaluate digital pressure measurements in the diagnosis of AV access-induced hand ischemia. A case-control study of 40 patients with an upper extremity AV access consisted of 15 patients (38%) with clinical AV access-induced hand ischemia and 25 patients (62%) without clinical evidence of ischemia. Arterial pressure in the third finger ipsilateral to the AV access was measured by digital photoplethysmography. Basal digital pressure (BDP), digital to contralateral brachial index (DBI), and change in digital pressure with access compression (CDP) were determined. Logistic regression modeling with gains tables and ROC calculations were used to determine optimal test thresholds and to test model discrimination for predicting AV access-induced hand ischemia. The mean BDP (30 vs 102 mmHg; p < 0.001) and mean DBI (0.3 vs 0.8; p < 0.001) were significantly lower in patients with AV access-induced hand ischemia than in those without. The accuracy for determining hand ischemia using a threshold-adjusted BDP of 60 mmHg was 92% (sensitivity 100%, specificity 87%) and using DBI of 0.4 was 94% (sensitivity 92%, specificity 96%). While the mean CDP was significantly higher in patients with hand ischemia (85 vs 40; p < 0.001), the accuracy for predicting ischemia was marginal (78%). In conclusion, a BDP less than 60 mmHg or a DBI less than 0.4 in a patient with an AV access were highly associated with hand ischemia. CDP's marginal discrimination ability likely stems from the presence of asymptomatic physiologic steal in the group without clinical steal. Nonetheless, CDP may be useful in identifying patients with ischemia who will not benefit from an intervention that specifically targets the AV access.