Lower Extremity Vein Bypass Research Articles

Abstract 76: Preoperative Genome-wide Differences in Inflammatory Gene Expression Predict Success Versus Failure in Lower Extremity Vein Bypass

Introduction: Vein bypass grafting is standard surgical therapy in the treatment for peripheral arterial disease (PAD), especially for those with limb threatening ischemia. However, the durability of vein grafts remains problematic with recent studies reporting disappointing 1-year primary patency rates as low as 61%. We hypothesized that an individual’s systemic inflammatory state, characterized by genome-wide inflammatory gene expression, would be predictive of ultimate clinical success or failure of these grafts. Methods: 41 patients undergoing vein bypass grafting for symptomatic PAD (85% critical limb ischemia; 25% claudication) had complete pre-operative gene expression data for analysis and one-year follow-up. There were 16 failures (39%) by one-year. Gene expression was analyzed for the entire genome using the novel Affymetrix GGH2 6.9 million feature oligonucleotide array system. Expression levels for the 35,123 gene transcripts and initial unsupervised and supervised (success/failure outcome) clustering was performed using BRB array tools. To then determine the additional predictive influence of specific genes or groups of genes, a novel objective Bayes method for dichotomous outcomes using stochastic search algorithms and probit regression models was employed. A series of increasingly predictive candidate models of gene combinations were derived. Clinical parameters including Rutherford disease severity score at presentation, vein conduit (GSV vs. composite vein), diabetes, smoking, statin use, and antiplatelet/anticoagulant use were standardized in the predictive model. Results: A random search through the space of possible models including the six clinical covariates and different combinations of gene products was executed, resulting in a list of 20 models ranked based on their posterior probabilities. The additional predictive power of the top gene products are listed in Table 1 and genes with the highest marginal posterior probabilities are listed in Table 2. This modeling approach suggests that the genes identified, independent of any relationship functionally, exhibit class prediction potential for bypass outcome. Conclusions: Using both a powerful and novel gene array system and a novel probit model selection method, we were able to identify a small number of gene clusters with predictive capability for bypass success or failure. This may both be prognostic and feasible for use in clinical practice as a point-of-care tool moving forward. Validation of these models is currently underway.

Genome-Wide Changes In Inflammatory Gene Expression Following Lower Extremity Vein Bypass

Introduction: Vein bypass grafting is standard surgical therapy in the treatment for peripheral arterial disease, especially for those with limb threatening ischemia. Technical success is high, but durability remains a challenging problem with recent studies reporting disappointing 1-year primary patency rates as low as 61%. We hypothesize that systemic inflammatory gene expression, either at baseline and/or during the early post-surgical response, is significantly perturbed in patients undergoing vein bypass surgery.

What is the Optimum Perioperative Drug Therapy Following Lower-Extremity Vein Bypass Surgery?

While endoluminal procedures are now commonly done for symptomatic peripheral arterial disease, vein bypass remains the gold standard for revascularization. Lower extremity vein bypass procedure success is dependent on patient factors, surgical judgment and technique, including use of medications. Cardioprotective medications have proven efficacy to decrease morbidity and mortality, but their use to improve graft patency is less well known. We review the up to date use of medications with known vascular effects that may promote graft success, as well as decrease cardiovascular events in this high risk patient group.

Female gender and oral anticoagulants are associated with wound complications in lower extremity vein bypass: An analysis of 1404 operations for critical limb ischemia

Female gender and oral anticoagulants are associated with wound complications in lower extremity vein bypass: An analysis of 1404 operations for critical limb ischemia

Prospective multicenter study of quality of life before and after lower extremity vein bypass in 1404 patients with critical limb ischemia

Prospective multicenter study of quality of life before and after lower extremity vein bypass in 1404 patients with critical limb ischemia

Prospective multicenter study of quality of life before and after lower extremity vein bypass in 1404 patients with critical limb ischemia

Prospective multicenter study of quality of life before and after lower extremity vein bypass in 1404 patients with critical limb ischemia

Elevated C-reactive protein levels are associated with postoperative events in patients undergoing lower extremity vein bypass surgery

Elevated C-reactive protein levels are associated with postoperative events in patients undergoing lower extremity vein bypass surgery

Female gender and oral anticoagulants are associated with wound complications in lower extremity vein bypass: An analysis of 1404 operations for critical limb ischemia

Infrainguinal bypass (IB) surgery is an effective means of improving arterial circulation to the lower extremity for patients with critical limb ischemia (CLI). However, wound complications (WC) of the surgical incision following IB can impart significant morbidity. A retrospective analysis of WC from the 1404 patients enrolled in a multicenter clinical trial of vein bypass grafting for CLI was performed. Univariate and multivariable regression models were used to determine WC predictors and associated outcomes, including graft patency, limb salvage, quality of life (QoL), resource utilization (RU), and mortality. A total of 543 (39%) patients developed a reported WC within 30 days of surgery, with infections (284, 52%) and hematoma/hemorrhage (121, 22%) being the most common type. Postoperative anticoagulation (odds ratio [OR], 1.554; 95% confidence interval [CI] 1.202 to 2.009; P = .0008) and female gender (OR, 1.376; 95% CI, 1.076 to 1.757; P = .0108) were independent factors associated with WC. Primary, primary-assisted, and secondary graft patency rates were not influenced by the presence of WC; though, patients with WC were at increased risk for limb loss (hazard ratio [HR], 1.511; 95% CI 1.096 to 2.079; P = .0116) and higher mortality (HR, 1.449; 95% CI 1.098 to 1.912; P = .0089). WC was not significantly associated with lower QoL at 3 months (4.67 vs 4.79, P = .1947) and 12 months (5.02 vs 5.13, P = .2806). However, the subset of patients with serious WC (SWC) demonstrated significantly lower QoL at 3 months compared with patients without WC, (4.43 vs 4.79, respectively, P = .0166), though this difference was not seen at 12 months (4.94 vs 5.13, P = .2411). Patients with WC had higher RU than patients who did not have WC. Mean index length of hospital stay (LOS) was 2.3 days longer, mean cumulative 1-year LOS was 8.1 days longer, and mean number of hospitalizations was 0.5 occurrences greater for patients with WC compared with patients without WC (all P < .0001). WC is a frequent complication of IB for CLI, associated with increased risk for major amputation, mortality, and greater RU. Further detailed investigation into the link between female gender and oral anticoagulation use with WC may help identify causes of WC and perhaps prevent or lessen their occurrence.

Infrainguinal vein graft surveillance: how and when.

Graft surveillance has evolved over the last 15 years into a useful clinical tool designed to reduce the incidence of lower extremity vein bypass graft occlusion. Graft surveillance has not been shown to be efficacious in improving patency of prosthetic leg bypasses. However, the most common cause of infrainguinal vein graft occlusion is intrinsic graft stenosis. Vein graft lesions, or flow disturbances, develop in approximately one third of lower extremity autogenous vein grafts. These lesions frequently progress and ultimately are responsible for 60% to 80% of all vein graft occlusions. Surveillance protocols allow the vascular surgeon to identify such graft-threatening lesions and monitor them for progression, stabilization, or resolution based on measurements of peak systolic flow velocity, velocity ratio, end-diastolic velocity, and other simple hemodynamic parameters. There is a substantial body of clinical evidence, and a single prospective, randomized trial that suggest that lower extremity graft surveillance is clinically useful, cost effective, and likely improves long-term graft patency and limb salvage rates by 10% to 15%.