Outcomes Of Lower Extremity Bypass Research Articles

Supra-Inguinal Inflow for Distal Bypasses Have Acceptable Patency and Limb Salvage Rates

There is a paucity of data evaluating outcomes of lower extremity bypass (LEB) using supra-inguinal inflow for revascularization of infra-inguinal vessels. The purpose of this study is to report outcomes after LEB originating from aortoiliac arteries to infra-femoral targets. The Vascular Quality Initiative database (2003-2020) was queried for patients undergoing LEB from the aortoiliac arteries to the popliteal and tibial arteries. Patients were stratified into 3 cohorts based on outflow targets (above-knee [AK] popliteal, below-knee [BK] popliteal, and tibial arteries). Perioperative and 1-year outcomes including primary patency, amputation-free survival (AFS), and major adverse limb events (MALEs) were compared. A Cox proportional hazards model was used to estimate the independent prognostic factors of outcomes. Of 403 LEBs, 389 (96.5%) originated from the external iliac artery, while the remaining used the aorta or common iliac artery as inflow. In terms of the distal target, the AK popliteal was used in 116 (28.8%), the BK popliteal in 151 (27.5%), and tibial vessels in 136 (43.7%) cases. BK popliteal and tibial bypasses, compared to AK popliteal bypasses, were more commonly performed in patients with chronic limb-threatening ischemia (69.5% and 69.9% vs. 48.3%; P<0.001). Vein conduit was more often used for tibial bypass than for AK and BK popliteal bypasses (46.3% vs. 21.9% and 16.3%; P<0.001). In the perioperative period, BK popliteal and tibial bypass patients had higher reoperation rates (16.9% and 13.2% vs. 5.2%; P=0.02) and lower primary patency (89.4% and 89% vs. 95.7%; P=0.04) than AK bypass patients. At 1year, compared with AK popliteal bypasses, BK and tibial bypasses demonstrated lower primary patency (81.9% vs. 56.7% vs. 52.4%, P<0.001) and freedom from MALE (77.6% vs. 70.2% vs. 63.1%, P=0.04), although AFS was not significantly different (89.7% vs. 90.6% vs. 83.8%, P=0.19).On multivariable analysis, compared with AK popliteal bypasses, tibial bypasses were independently associated with increased loss of primary patency (hazard ratio 1.9, 95% confidence interval, 1.03-3.51, P=0.04). Subanalysis of patients with chronic limb-threatening ischemia demonstrated significantly higher primary patency in the AK popliteal cohort at discharge and 1 year, but no difference in AFS or freedom from MALE between the cohorts at follow-up. LEB with supra-inguinal inflow appear to have acceptable rates of 1-year patency and limb salvage in patients at high risk of bypass failure. Tibial outflow target was independently associated with worse primary patency but not with MALE or AFS.

Long-Term Outcome of Lower Extremity Bypass Surgery in Diabetic and Non-Diabetic Patients with Critical Limb-Threatening Ischaemia in Germany.

To present the short- and long-term outcomes of lower extremity bypass (LEB) surgery in patients with critical limb-threatening ischaemia (CLTI), comparing diabetic (DM) and non-diabetic (non-DM) patients. Retrospective analysis of anonymised data from a nationwide health insurance company (AOK). Data from 22,633 patients (DM: n = 7266; non-DM: n = 15,367; men: n = 14,523; women: n = 8110; mean patient age: 72.5 years), who underwent LEB from 2010 to 2015, were analysed. The cut-off date for follow-up was December 31, 2018 (mean follow-up period: 55 months). Perioperative mortality was 10.0% for DM and 8.2% for non-DM (p < 0.001). Patients with crural/pedal bypasses (n = 8558) had a significantly higher perioperative mortality (10.3%) than those with above-the-knee (n = 7246; 5.8%; p < 0.001) and below-the-knee bypasses (n = 6829; 8.9%; p = 0.003). The 9-year survival rates in DM patients were significantly worse, at 21.5%, compared to non-DM, at 31.1% (p < 0.001). This applied to both PAD stage III (DM: 34.4%; non-DM: 45.7%; p < 0.001) and PAD stage IV (DM: 18.5%; non-DM: 25.0%; p < 0.001). Patients with crural/pedal bypasses had a significantly inferior survival rate (25.5%) compared to those with below-the-knee (27.7%; p < 0.001) and above-the-knee bypasses (31.7%; p < 0.001). Perioperative and long-term outcomes regarding survival and major amputation rate for CLTI patients undergoing LEB are consistently worse for DM patients compared to non-DM patients.

Black Patients Have Worse Outcomes After Lower Extremity Revascularization: A Propensity-matched Analysis of Comorbidities and Socioeconomic Factors

Racial disparities among patients with peripheral artery disease (PAD) have been described and often attributed to sociodemographic factors. We analyzed the outcomes of lower extremity bypass (LEB) and peripheral vascular intervention (PVI) between Black and non-Hispanic White (NHW) while accounting for socio-economic status using the area of deprivation index (ADI). The Vascular Quality Initiative (2016-2021) datasets were used to identify patients undergoing LEB and PVI. A probit regression model was used to generate propensity scores and perform a 5:1 match on characteristics including comorbidities, ADI, indication, urgency, and number of arteries treated (PVI) or graft target (LEB). The primary outcome was major adverse limb event (MALE)-free survival at 1 year. Kaplan-Meier survival graphs were generated for the groups and compared using log-rank testing. Cox regression analyses was used to test for interactions between race and indications as well as race and number of arteries treated (for PVI) or graft target (for LEB). A total of 44,968 PVI and 12,006 LEB were included in the analysis after matching. Black patients had significantly higher rates of MALE at 1 year for both PVI and LEB (Figs 1 and 2). On adjusted analyses Black patients with chronic limb-threatening ischemia had a higher risk of MALE at 1 year for both PVI (HR, 1.11; 95% CI, 1.04-1.17; P < .001) and LEB (HR, 1.11; 95% CI, 1.01-1.19; P = .03) compared to NHW. When adjusting for anatomical considerations, there was variability of outcomes between the groups. Black patients had a higher risk of MALE at 1 year in LEB performed to peroneal and tibial target vessels (HR, 1.17; 95% CI, 1.04-1.31; P = .007), but not for popliteal target vessels. For PVI, 1-year MALE was also higher in Black patients with one or two vessels treated at any level (HR, 1.21; 95% CI, 1.13-1.26; P < .001), but rates were similar to NHW with more vessels treated. Despite adjusting for socioeconomic factors using the validated ADI, Black patients with PAD have worse outcomes following revascularization, especially for CLTI, suggesting that other factors adversely affect outcomes in these patients. These unmeasured factors require further exploration to improve PAD outcomes in Black patients.Fig 2Major adverse limb event (MALE)-free survival at 1 year after lower extremity bypass (LEB).View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Outcomes of Lower Extremity Bypass for Chronic Limb-threatening Ischemia in Patients with Chronic Kidney Disease

Outcomes of Lower Extremity Bypass for Chronic Limb-threatening Ischemia in Patients with Chronic Kidney Disease

Patients Undergoing Bypass for Infrapopliteal Chronic Limb-Threatening Ischemia Have Better 2-Year Outcomes Than Those Undergoing Endovascular Peripheral Vascular Interventions

Endovascular interventions (peripheral vascular interventions [PVI]) have become first-line in patients with infrapopliteal chronic limb-threatening ischemia (IP-CLTI). We analyzed the outcomes of lower extremity bypass (LEB) to tibial targets compared with PVI in patients with infrapopliteal targets for CLTI (IP-CLTI) as the initial treatment. We queried the Vascular Quality Initiative LEB and PVI databases from 2003 to 2021 to identify elective tibial LEB or PVI in patients with IP-CLTI. All patients with prior ipsilateral lower extremity interventions (PVI/LEB), emergent interventions, or interventions for claudication were excluded. Primary outcomes were primary patency, major adverse limb events (MALE) defined as vascular reintervention or above-ankle amputation, and amputation-free survival at 2 years. Standard statistical methods were used. We identified 24,806 procedures (18,198 PVI, 6608 LEB). The use of PVI has increased over time in the cohort from 49.7% in 2010 to 82.25% in 2021 (P < .001). Patients who underwent PVI were older, less frequently male, and had more comorbid conditions. Patients undergoing PVI were more likely to present with Rutherford class 5/6 ischemia compared with LEB (Table). Among PVI cases, 46% (8330) were isolated tibial interventions, the remainder involved multiple levels. Although 85% (5574) of LEB were to tibial targets with the remainder involving pedal or plantar targets. LEB had statistically significantly higher rates of postoperative morbidity in terms of major adverse cardiac events. Although postoperative mortality at 30 days was low in both groups but was significantly higher in the PVI cohort (1.77% PVI; 1.07% LEB; P < .001) (Table). On unadjusted Kaplan-Meier survival analysis, the LEB group had a significantly higher primary patency at 2 years (52% ± 2.04% LEB vs 34.13% ± 1.6% PVI; P = .011) compared with the PVI group, a similar pattern was seen for freedom from MALE at 2 years (40.44% ± 1.9% LEB vs 27.39% ± 1.37% PVI; P = .03) (Table). LEB had a significantly higher amputation-free survival at 2 years (73.7% ± 0.5% LEB vs 64.61% ± 0.38% PVI; P < .001) compared with PVI (Figure). In an adjusted Cox regression model (adjusted for comorbidities and Rutherford class), PVI was independently associated with loss of primary patency (hazard ratio [HR], 1.1; 95% confidence interval [CI], 1.03-1.11; P = .006) and increased risk of amputation or death (HR, 1.25; 95% CI, 1.17-1.33; P < .001), but it was not significantly associated with MALE (HR, 1.04; 95% CI, 0.98-1.11; P = .238) (Table). Surgical bypass outcomes are superior to endovascular intervention in patients with IP-CLTI. In medically and anatomically appropriate candidates, LEB should be considered first line even in the endovascular era.TableDemographics and outcomes of endovascular interventions compared with surgical bypassEndovascular (n = 18,198)Bypass (n = 6606)P valueDemographics Age, years71.0 ± 12.169.00 ± 11.27<.001 Male sex11,880 (65.28)4783 (72.4)<.001 White11,702 (64.33)4711 (71.29)<.001 History of diabetes13,616 (74.84)4005 (60.63)<.001 History of coronary artery disease6040 (33.21)2082 (31.55).014 Prior coronary artery bypass grafting3796 (22.18)1286 (23.22)>.05 Prior PCI3709 (21.68)1131 (20.43).048 History of congestive heart failure5190 (28.53)1444 (21.86)<.001 History of chronic obstructive pulmonary disease3409 (18.74)1427 (21.6)<.001 History of hypertension16,400 (90.52)5943 (90.2)>.05 On dialysis3351 (18.42)621 (9.4)<.001 Current/former smoker10,172 (55.98)4890 (74.05)<.001 Obese6449 (35.44)1916 (29)<.001 Rutherford class 5/6 ischemia (tissue loss)15,523 (85.3)4756 (71.97)<.001Type of InterventionNA Unknown249 (1.38)0 (0) Plain balloon angioplasty11,953 (66.4)0 (0) Atherectomy2773 (15.4)0 (0) ther balloon angioplasty1727 (9.59)0 (0) Stn1300 (7.22)0 (0) Bypass0 (0)6608 (100)Postoperative outcomes Major adverse cardiac events166 (1.4)577 (9.52)<.001 Postoperative myocardial infarction53 (0.45)239 (3.62)<.001 Postprocedure pulmonary complication69 (0.58)110 (1.67)<.001 In-hospital mortality80 (0.44)16 (0.24).027 30-Day mortality323 (1.77)71 (1.07)<.001Kaplan-Meier survival analysis at 2 years Primary patency, % ± SEM %34.13% ± 1.6%52% ± 2.04%.011 Freedom from MALE27.39% ± 1.37%40.44% ± 1.9%.03Amputation-free survival64.61% ± 0.38%73.7% ± 0.5%<.001Adjusted Cox proportional hazard models at 2 years Primary patency1.1 [1.03-1.11]ref.006 MALE1.04 [0.98-1.11]ref.238Amputation-free survival1.25 [1.17-1.33]ref<.001MALE, Major adverse limb events; PCI, percutaneous coronary in intervention; SEM, standard error of the mean.Values are mean ± standard deviation or number (%) unless otherwise indicated. Open table in a new tab

A Comparison of Revised Frailty Score Range Association With National Lower Extremity Bypass Outcomes By Gender

INTRODUCTION AND OBJECTIVES The Risk Assessment Index (RAI) frailty scoring system, developed in an all-male veteran cohort, has recently undergone revision and validation using a general surgical sample from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We set forth to investigate the association between RAI-rev scores and lower extremity bypass outcomes by gender in the NSQIP database. METHODS All elective cases recorded from 2015-2019 in the NSQIP Targeted Lower Extremity Open database were paired with the Participant User File using Case IDs. Cohorts were defined by EMR-recorded gender. Top quartile postoperative length of stay was defined as extended. Aggregate cohort demographics, perioperative factors, and 30-day outcomes were compared using unpaired t-test and Fisher's exact test. Adjusted odds-ratios for outcomes were generated with a multivariate binary logistic regression model utilizing prior ipsilateral bypass versus percutaneous intervention, graft utilization, dirty/infected wound, smoking, hypertension, diabetes, and steroid use as covariates. Calculated RAI-rev scores <25 were defined as the non-frail reference range. RESULTS 8,155 bypass cases were recorded in NSQIP from 2015-2019 including 2,498 (31%) performed in women who had slightly lower RAI-rev scores on average (22.1 ± 5.8 vs 24.2 ±5.1; p=0.0001). While univariate trends suggested increasing incidence for most outcomes across both represented genders, there were more non-significant aOR for women than men (Table). Analysis of 4 patients with RAI-rev scores >45 resulted in no significant aOR. CONCLUSIONS Our study is the first to find that outcomes other than mortality are significantly predicted by RAI-rev score ranges in lower extremity bypass. Stratification of aOR by gender suggests that additional validation of frailty scores may be warranted as these systems gain wider use. The Risk Assessment Index (RAI) frailty scoring system, developed in an all-male veteran cohort, has recently undergone revision and validation using a general surgical sample from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We set forth to investigate the association between RAI-rev scores and lower extremity bypass outcomes by gender in the NSQIP database. All elective cases recorded from 2015-2019 in the NSQIP Targeted Lower Extremity Open database were paired with the Participant User File using Case IDs. Cohorts were defined by EMR-recorded gender. Top quartile postoperative length of stay was defined as extended. Aggregate cohort demographics, perioperative factors, and 30-day outcomes were compared using unpaired t-test and Fisher's exact test. Adjusted odds-ratios for outcomes were generated with a multivariate binary logistic regression model utilizing prior ipsilateral bypass versus percutaneous intervention, graft utilization, dirty/infected wound, smoking, hypertension, diabetes, and steroid use as covariates. Calculated RAI-rev scores <25 were defined as the non-frail reference range. 8,155 bypass cases were recorded in NSQIP from 2015-2019 including 2,498 (31%) performed in women who had slightly lower RAI-rev scores on average (22.1 ± 5.8 vs 24.2 ±5.1; p=0.0001). While univariate trends suggested increasing incidence for most outcomes across both represented genders, there were more non-significant aOR for women than men (Table). Analysis of 4 patients with RAI-rev scores >45 resulted in no significant aOR. Our study is the first to find that outcomes other than mortality are significantly predicted by RAI-rev score ranges in lower extremity bypass. Stratification of aOR by gender suggests that additional validation of frailty scores may be warranted as these systems gain wider use.

Suprainguinal Inflow for Bypasses to Popliteal and Tibial Arteries Have Acceptable Patency and Limb Salvage Rates

There is a paucity of data evaluating outcomes of lower extremity bypass (LEB) using suprainguinal inflow for infrainguinal vessels. The purpose of this study is to report outcomes after LEB originating from aortoiliac arteries to infrafemoral targets.

Surgeon Experience Is More Important Than Volume in Predicting Better Outcomes for Lower Extremity Bypass in Contemporary Practice

Growing calls for minimum case thresholds to sustain surgeon credentialing are mounting in contemporary practice. To date, the volume-outcome relationship and the role of surgeon experience has remained confined to nonvascular extirpative surgery and aneurysm repair. It is unclear whether this work can be extrapolated to predict lower extremity bypass (LEB) outcomes. Accordingly, the purpose of this study was to examine whether annualized case volume versus surgeon experience is more consequential in predicting successful LEB reconstruction.

Impact of Medicaid Expansion of the Affordable Care on the Outcomes of Lower Extremity Bypass for Patients With Peripheral Artery Disease in the Vascular Quality Initiative Database.

The aim of this study was to evaluate changes in the utilization and outcomes of surgery after Medicaid Expansion (ME) for patients with peripheral artery disease (PAD). Recent studies have demonstrated increased insurance coverage and improved care with the Affordable Care Act's (ACA) state expansion of Medicaid. Infrainguinal bypass procedures performed due to occlusive pathology in the Vascular Quality Initiative database between 2010 and 2017 were included. Primary outcomes including postoperative mortality and major adverse limb events (MALE) at 1-year of follow-up were analyzed using interrupted time-series analysis (ITS). Out of 26,446 infrainguinal bypass procedures, 13,955 (52.8%) were included in this analysis. ME states witnessed an annual decrease in infrainguinal surgery for acute ischemia [annual change in post vs pre-ME period (95% confidence interval): -4.3% (-7.5% to -1.0%), P = 0.02] and an increase in revascularization for claudication [3.7% (1.7%-5.6%), P = 0.01]. Among nonacute cases, elective procedures increased in ME states [3.9% (0.1%-7.7%), P = 0.05] along with a significant annual decrease in in-hospital mortality [-0.4% (-0.8 to -0.02), P = 0.04) and MALE at 1 year of follow up [-9.0% (-20.3 to 2.3), P = 0.09]. These results were statistically significant after comparing them with the annual trend changes in states which did not adopt ME. The adoption of ME in 2014 was associated with significant increase in the use of infrainguinal bypass for nonsevere and elective cases, along with improved in-hospital mortality and MALE at 1 year. Longer follow-up is needed to evaluate the impact of ME on other aspects of care and longer term outcomes of PAD patients.

Utilization of regional versus general anesthesia and its impact on lower extremity bypass outcomes

ObjectivePrevious studies evaluating general anesthesia (GA) vs regional (epidural/spinal) anesthesia (RA) for infrainguinal bypass have produced conflicting results. The purpose of this study was to analyze the factors associated with contemporary use of RA and to determine whether it is associated with improved outcomes after infrainguinal bypass in patients with critical limb ischemia. MethodsUsing the Vascular Quality Initiative infrainguinal database, a retrospective review identified all critical limb ischemia patients who received an infrainguinal bypass from 2011 through 2016. Patients were then separated by GA or RA. Primary outcomes were perioperative mortality, complications, and length of stay. Predictive factors for RA and perioperative outcomes were analyzed using a mixed-effects model to adjust for center differences. ResultsThere were 16,052 patients identified to have a lower extremity bypass during this time frame with 572 (3.5%) receiving RA. There was a wide variation in the use of RA, with 31% of participating centers not using it at all. Age (67.2 vs 70.3 years; P < .001), chronic obstructive pulmonary disease (25.7% vs 30.9%; P < .001), and urgency of the operation (75.7% vs 80.4%; P = .01) were found to be independently associated with receiving a regional anesthetic. Univariate and multivariate analysis demonstrated that length of stay (6.8 days vs 5.7 days; P < .01), postoperative congestive heart failure (2.3% vs 1.1%; P = .040), and change in renal function (5.7% vs 2.9%; P = .005) were all significant outcomes in favor of RA. There was a trend toward lower mortality rates; however, this did not reach statistical significance. Rates of myocardial infarction, pulmonary complications, and stroke were not found to be statistically different. Coarsened exact matching continued to demonstrate a difference in length of stay and rates of new-onset congestive heart failure in favor of RA. ConclusionsRA is an infrequent but effective form of anesthesia for infrainguinal bypass surgery. Elderly patients and those with underlying respiratory problems may benefit from this form of anesthesia. Further evaluation within institutions should be performed to identify which patients would most benefit from RA or GA.

Association between Drug Use and In-hospital Outcomes after Infrainguinal Bypass for Peripheral Arterial Occlusive Disease

Drug abuse may affect lower extremity vessels due to ischemia following intra-arterial injections, vasospasm, arterial and venous pseudoaneurysms, arteriovenous fistulae, vasculitis, and complicated abscesses. Little is known about the outcomes of lower extremity bypass (LEB) for peripheral arterial disease (PAD) in patients with a history of drug abuse disorder. The aim of this study is to evaluate the outcomes of LEB in this patient population. A retrospective study of the Premier Healthcare Database 2009-2015 was performed. In-hospital complications, mortality, and hospitalization costs were assessed in patients with a history of drug abuse disorder (opioids, cannabis, cocaine, sedatives/hypnotics/anxiolytics, and hallucinogens/methamphetamine/psychoactive drugs) who underwent LEB for PAD. Multivariable logistic and generalized linear models were utilized to study the association between drug use/misuse and in-hospital outcomes after LEB. Our cohort included 50,976 patients, of which 967 (2%) had a history of drug abuse disorder on admission. The majority of drugs were cannabis (38.5%), followed by opioids (21.5%) and cocaine (14.5%). Patients with a history of drug use/misuse were significantly at a higher risk of developing complications during their hospital stay (71.9% vs. 64.2%, P<0.001) including acute renal failure (11.8% vs. 9.1%), stroke (1.6% vs. 0.6%), respiratory complications (pneumonia and respiratory failure) (15.0% vs. 9.6%), hemorrhage/shock (36.2% vs. 31.8%), vascular or graft-related complications (29.8% vs. 26.4%), wound complications (9.1% vs. 6.3%), cellulitis (8.5% vs. 6.8%), and sepsis (2.1% vs. 1.2%, all P<0.001). In addition, drug users were found to have higher risk of concomitant major amputations compared to nondrug users (2.0% vs. 0.9%, P<0.001). On multivariable analysis, no difference was noted between the 2 groups in terms of in-hospital mortality and concomitant major amputations. However, drug use/misuse was associated with 57% higher odds of overall in-hospital complications (odds ratio [OR] 1.57, 95% confidence interval [CI] 1.34-1.83, P<0.001), a prolonged length of hospital stay (median: 7days vs. 5days in nonabusers, P<0.001), and higher hospitalization costs compared to nonusers (adjusted mean difference: OR $3,075, 95% CI $2,096-$4,055, P<0.001). Drug use/misuse is significantly associated with increased odds of in-hospital complications, longer hospital stays, and higher hospitalization costs following LEB. Vascular surgeons need to pay special attention to this patient population and explore interventions to decrease the morbidity and economic burden associated with drug use.

NESVS10. Outcomes of Lower Extremity Bypass After Failed Endovascular or Open Revascularization Are Inferior to Bypasses Without Prior Intervention

Outcomes of lower extremity bypass (LEB) after failed lower extremity interventions have almost exclusively been studied in the short term, and the role of changes in runoff remains unclear. The goal of this study was to assess long-term outcomes of LEB after failed endovascular (peripheral vascular intervention [PVI]) or open (bypass graft [BPG]) revascularization and to determine the effect of PVI on distal bypass targets. Patients who underwent infrainguinal LEB for critical limb ischemia between 2010 and 2017 at our institution were included. Patients were stratified into three cohorts based on prior intervention: PVI, BPG, and none. Primary end points were major amputation, graft patency, and amputation-free survival (AFS). Univariate analysis was performed, and predictors of AFS were determined. In 148 patients, 160 procedures were stratified by previous intervention: 74 (46%) PVI, 25 (16%) BPG, and 61 (38%) none. Most patients were male (71%) and diabetic (56%). BPG patients were more likely to have compromised conduit (80%; P = .03), whereas PVI patients were more likely to be diabetic (68%; P = .01); 75% of LEB patients had a below-the-knee distal target, and there were no differences in above-knee vs below-knee targets between the cohorts (P = .15). There were no differences in 30-day complications. Overall major ipsilateral amputation rate was 14%. The none cohort had higher overall freedom from amputation (P = .045). The BPG cohort had decreased rates of primary patency (P = .03) and higher rates of graft occlusion (P = .03). The none cohort had better survival at 1 year and 2 years (85% and 79%). There was no difference in long-term AFS (5 years, 46%; P = .228). End-stage renal disease and conduit were negative predictors of AFS (P < .01). The number of prior PVIs did not affect 30-day or long-term outcomes. After PVI, 41 (55%) had either a runoff or distal target change at LEB. Patients who undergo LEB without prior intervention have better graft patency and amputation outcomes, but the demonstrated benefit for AFS is short-lived. More than half of patients who underwent PVI before LEB had either runoff or distal target change, which may be a contributor to the differences seen in graft patency and amputation outcomes.

The impact of chronic kidney disease on lower extremity bypass outcomes in patients with critical limb ischemia

ObjectivePatient selection for open lower extremity revascularization in patients with chronic kidney disease (CKD) remains a clinical challenge. This study investigates the impact of CKD on early graft failure, postoperative complications, and mortality in patients undergoing lower extremity bypass for critical limb ischemia. MethodsThe National Surgical Quality Improvement Program database was queried for all patients with critical limb ischemia from 2012 to 2015 who underwent lower extremity bypass using the targeted vascular set. The glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration Study equation. CKD categories were determined from the National Kidney Foundation Kidney Disease Outcomes Quality Initiative staging criteria. Patients were classified into three groups: CKD stages 3 or lower (mild to moderate CKD), CKD stages 4 or 5 (severe CKD), and on hemodialysis (HD). Multiple variable analysis was used to examine graft failure, mortality, and postoperative complications. ResultsThe Surgical Quality Improvement Program database identified 6978 patients who underwent infrainguinal lower extremity arterial bypass during the study period. There were 6101 patients (87.4%) with mild to moderate CKD, 327 (4.7%) with severe CKD, and 550 (7.9%) on HD. Patients with severe CKD and on HD were more likely to have revascularization for tissue loss (54.9% vs 68.8% and 74.7%; P < .01). Patients with severe CKD and those on HD had higher rates of early graft failure, postoperative myocardial infarction, and rates of reoperation. Multiple variable analysis confirmed these results showing that HD was associated with postoperative myocardial infarction, readmission, and increased mortality. It also demonstrated that severe CKD was associated with graft failure (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.12-2.50; P = .01), postoperative myocardial infarction (OR, 2.16; 95% CI, 1.35-3.45; P < .01), and readmission (OR, 1.38; 95% CI, 1.06-1.80; P = .02). Other factors associated with graft failure include functional status (OR, 1.39; 95% CI, 1.08-1.80; P = .01), African American race (OR, 1.72; 95% CI, 1.39-2.13; P < .01), and distal bypass (OR, 1.33; 95% CI, 1.09-1.61; P < .01). ConclusionsCKD is a significant predictor of perioperative morbidity after lower extremity bypass. Patients with severe CKD have worse postoperative outcomes without increased mortality. Those on HD have worse survival and postoperative outcomes.

Increased warm ischemia time during vessel harvest decreases the primary patency of cryopreserved conduits in patients undergoing lower extremity bypass

ObjectiveAutologous vein is the preferred conduit for lower extremity bypass. However, it is often unavailable because of prior harvest or inadequate for bypass owing to insufficient caliber. Cryopreserved cadaveric vessels can be used as conduits for lower extremity revascularization when autogenous vein is not available and the use of prosthetic grafts is not appropriate. Many studies have shown that donor characteristics influence clinical outcomes in solid organ transplantation, but little is known regarding their impact in vascular surgery. The purpose of this study was to examine the effects donor variables have on patients undergoing lower extremity bypass with cryopreserved vessels. MethodsThe tissue processing organization was queried for donor blood type, warm ischemia times (WITs), and serial numbers of cryopreserved vessels implanted at a single center from 2010 to 2016. The serial numbers were then matched with their respective patients using the institutional Clinical Data Repository and patient data were obtained from the Clinical Data Repository and chart review. Primary outcomes were primary patency of the bypass conduits and limb salvage. Time to loss of patency was evaluated using Kaplan-Meier methods and a Cox proportional hazards model determined risk-adjusted predictors of patency and limb salvage. ResultsSixty patients underwent lower extremity bypass with 65 cryopreserved vessels (23 superficial femoral arteries, 41 saphenous veins, 1 femoral vein). Thirty-eight procedures were reoperations. There were 21 inflow, 44 outflow, and 44 infrainguinal procedures. Preexisting comorbidities did not differ significantly between those who lost patency and those who did not. The mean WIT among the entire cohort was 892.3 ± 389.1 minutes (range, 158.0-1434.0 minutes). The median follow-up was 394 days. Kaplan-Meier analysis demonstrated an overall 1-year primary patency rate of 51%. Primary patency at 1 year was 67% and 41% for inflow and outflow procedures, respectively, and did not differ significantly between the two groups (P = .15). Donor-to-recipient ABO incompatibility was not associated with loss of primary patency. The 1-year amputation-free survival was 74%. Primary patency significantly decreased with each hourly increase in WIT on risk-adjusted analysis (hazard ratio, 1.1; P = .02). ConclusionsHigher cryopreserved vessel WIT was associated with increased risk-adjusted loss of primary patency in this cohort. At 1 year, the overall primary patency was 51% and amputation-free survival was 74%. Vascular surgeons should be aware that WIT may affect outcomes for lower extremity bypass.

Superior Lower Extremity Vein Graft Bypass Patency among Married Patients with Peripheral Artery Disease

Outcome disparities associated with lower extremity bypass (LEB) for peripheral artery disease (PAD) have been identified but are poorly understood. Marital status may affect outcomes through factors related to health risk behaviors, adherence, and access to care but has not been characterized as a predictor of surgical outcomes and is often omitted from administrative data sets. We evaluated associations between marital status and vein graft patency following LEB using multivariable models adjusting for established risk factors. Consecutive patients undergoing autogenous LEB for PAD were identified and analyzed. Survival analysis and Cox proportional hazards models were used to evaluate patency stratified by marital status (married versus single, divorced, or widow[er]) adjusting for demographic, comorbidity, and anatomic factors in multivariable models. Seventy-three participants who underwent 79 autogenous vein LEB had complete data and were analyzed. Forty-three patients (58.9%) were married, and 30 (41.1%) were unmarried. Compared with unmarried patients, married patients were older at the time of their bypass procedure (67.3±10.8years vs. 62.2±10.6years; P=0.05). Married patients also had a lower prevalence of female gender (11.6% vs. 33.3%; P=0.02). Diabetes, hypertension, hyperlipidemia, and smoking were common among both married and unmarried patients. Minimum great saphenous vein conduit diameters were larger in married versus unmarried patients (2.82±0.57mm vs. 2.52±0.65mm; P=0.04). Twenty-four-month primary patency was 66% for married versus 38% for unmarried patients. In a multivariable proportional hazards model adjusting for proximal and distal graft inflow/outflow, medications, gender, age, race, smoking, diabetes, and minimum vein graft diameter, married status was associated with superior primary patency (hazard ratio [HR] = 0.33; 95% confidence limits [0.11, 0.99]; P=0.05); other predictive covariates included preoperative antiplatelet therapy (HR=0.27; 95% confidence limits [0.10,0.74]; P=0.01) and diabetes (HR = 2.56; 95% confidence limits [0.93-7.04]; P=0.07). Marital status is associated with vein graft patency following LEB. Further investigation into the mechanistic explanation for improved patency among married patients may provide insight into social or behavioral factors influencing other disparities associated with LEB outcomes.

The role of Model for End-Stage Liver Disease (MELD) score in predicting outcomes for lower extremity bypass

The Model for End-Stage Liver Disease (MELD) score has traditionally been used to prioritize liver transplantation. However, its use has been extended to predict overall and postoperative outcomes in patients with hepatic and renal dysfunction. Our objective was to use the MELD score to predict outcomes in patients undergoing lower extremity bypass. Patients undergoing infrainguinal bypass were identified in the American College of Surgeons National Surgical Quality Improvement Program data sets from 2005 to 2012. The MELD score was calculated using serum bilirubin and creatinine values and the international normalized ratio. Patients were grouped into low (<9), moderate (9-14), and high (15+) MELD classifications. The associations of the MELD score on postoperative morbidity and mortality were assessed by multivariable logistic and gamma regressions and by propensity matching. There were 5967 patients who underwent infrainguinal bypass with the following MELD score distribution:<9, 3795 (64%); 9 to 14, 1819 (30%); and 15+, 353 (6%). Matched analysis in comparing low, moderate, and high MELD scores showed a higher risk for cardiac complications (2.8% vs 3.2% vs 5.4%; P< .001), bleeding complications (9.3% vs 11.1% vs 13.9%; P= .048), and increased postoperative length of stay (median [range], 5 [0-93] vs 6 [0-73] vs 6 [0-86]; P< .001). The MELD score had no association with early bypass failure, wound complications, or operative time. Moderate and high MELD scores were independent predictors of postoperative myocardial infarction/cardiac arrest (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.6-3.6; P< .001; and OR, 4.1; 95% CI, 2.3-7.3; P< .01), bleeding complications (OR, 1.3; 95% CI, 1.1-1.6; P< .01; and OR, 1.8; 95% CI, 1.3-2.5; P< .01), return to the operating room (OR, 1.3; 95% CI, 1.1-1.5; P< .01; and OR, 1.4; 95% CI, 1.03-1.8; P= .03), extended postoperative length of stay (means ratio, 1.2; 95% CI, 1.1-1.2; P< .01; and means ratio, 1.2; 95% CI, 1.2-1.3; P< .01), and perioperative mortality (OR, 1.6; 95% CI, 1.02-2.5; P= .04; and OR, 2.9; 95% CI, 1.6-5.4; P= .01), respectively. Propensity matching between low, moderate, and high MELD score groups confirmed an increased risk of postoperative myocardial infarction/cardiac arrest (P< .01), bleeding complications (P= .05), and extended postoperative length of stay (P< .01) with a trend toward increased mortality and return to operating room. An elevated MELD score places patients undergoing infrainguinal bypass at higher risk of perioperative morbidity and mortality. This provides an evidence base for risk stratification and informed consent for these patients. Alternative treatment may be considered in these patients; however, the overall morbidity and mortality rates may still be acceptable, even in high-risk patients.

The Role of Model of End-Stage Liver Disease (MELD) Score in Predicting Outcomes for Lower Extremity Bypass in Patients with Liver Disease

The Role of Model of End-Stage Liver Disease (MELD) Score in Predicting Outcomes for Lower Extremity Bypass in Patients with Liver Disease

The influence of gender on functional outcomes of lower extremity bypass

Our aim was to evaluate the effect of gender on early and late procedural and functional outcomes of lower extremity bypass (LEB). 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. 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). 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.

Current Outcomes of Lower Extremity Bypass in High-Risk Patients

Current Outcomes of Lower Extremity Bypass in High-Risk Patients

Race and gender affect outcomes of lower extremity bypass

Race and gender have individually been associated with affecting outcomes in vascular interventions. We hypothesized that race and gender stratification would identify variations in outcomes of lower extremity bypass (LEB) procedures. LEB procedures were identified using Current Procedural Terminology (American Medical Association, Chicago, Ill) codes from the 2011 American College of Surgeons National Surgical Quality Improvement Program database. Individuals of races other than black or white were excluded because of small sample size. Preoperative variables, such as age, demographics, medical comorbidities, and laboratory values, were evaluated across race and gender groups using χ(2), the Student t-test, and least square means testing. Significant predictors were entered into a multivariate logistic regression model. Six primary outcomes were evaluated: major complications, minor complications, 30-day mortality, early graft failure, readmission, and length of stay (LOS). There were 4518 LEB procedures performed on black (n= 839; male [BM], 56.5%; female [BF], 43.5%) or white (n= 3679; male [WM], 66.4%; female [WF], 33.6%) patients. Black patients were more likely to be younger, diabetic, smokers, functionally dependent, dialysis dependent, and have hypertension, critical limb ischemia, higher creatinine, lower hematocrits, and higher platelet counts. Multivariate analysis revealed no statistically significant gender differences within the white cohort with respect to complications, death, graft failure, or readmission rates. WF and BM had longer LOS than WM (reference group; 4.7± 1.9days and 5.4± 2.0days vs 4.3± 2.0days, respectively; P< .006 and P< .0001) after LEB procedures, but outcomes among these groups did not differ significantly. BF had a longer LOSthan WM (5.8± 2.0days vs 4.3± 2.0days; P< .0001) and trended toward higher readmission rates (odds ratio, 1.28; 95% confidence interval, 0.97-1.70; P= .08). BF had a higher risk of early graft failure than WM (odds ratio, 2.90; 95% confidence interval, 1.52-5.49; P= .001). BF had higher early graft failure and LOS compared with WM. WF and BM also had increased LOS compared with WM. Race-gender stratification may predict outcomes in patients undergoing LEB procedures that may not be predicted by gender or race alone. Further studies using this stratification methodology may provide better insight into optimal therapeutic strategies and preventative measures for these patient subgroups. Investigation into causes of increased LOS in black patients and increased graft failure in BF may help improve outcomes.