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.

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. rights reserved.

Peripheral arterial disease (PAD) continues to grow in global prevalence and consumes an increasing amount of resources in the United States health care system. Overall rates of intervention for PAD have been rising steadily in recent years. Changing demographics, evolution of technologies, and an expanding database of outcomes studies are primary forces influencing clinical decision making in PAD. The management of PAD is multidisciplinary, involving primary care physicians and vascular specialists with varying expertise in diagnostic and treatment modalities. PAD represents a broad spectrum of disease from asymptomatic through severe limb ischemia. The Society for Vascular Surgery Lower Extremity Practice Guidelines committee reviewed the evidence supporting clinical care in the treatment of asymptomatic PAD and intermittent claudication (IC). The committee made specific practice recommendations using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) system. There are limited Level I data available for many of the critical questions in the field, demonstrating the urgent need for comparative effectiveness research in PAD. Emphasis is placed on risk factor modification, medical therapies, and broader use of exercise programs to improve cardiovascular health and functional performance. Screening for PAD appears of unproven benefit at present. Revascularization for IC is an appropriate therapy for selected patients with disabling symptoms, after a careful risk-benefit analysis. Treatment should be individualized based on comorbid conditions, degree of functional impairment, and anatomic factors. Invasive treatments for IC should provide predictable functional improvements with reasonable durability. A minimum threshold of a > 50% likelihood of sustained efficacy for at least 2 years is suggested as a benchmark. Anatomic patency (freedom from restenosis) is considered a prerequisite for sustained efficacy of revascularization in IC. Endovascular approaches are favored for most candidates with aortoiliac disease and for selected patients with femoropopliteal disease in whom anatomic durability is expected to meet this minimum threshold. Conversely, caution is warranted in the use of interventions for IC in anatomic settings where durability is limited (extensive calcification, small-caliber arteries, diffuse infrainguinal disease, poor runoff). Surgical bypass may be a preferred strategy in good-risk patients with these disease patterns or in those with prior endovascular failures. Common femoral artery disease should be treated surgically, and saphenous vein is the preferred conduit for infrainguinal bypass grafting. Patients who undergo invasive treatments for IC should be monitored regularly in a surveillance program to record subjective improvements, assess risk factors, optimize compliance with cardioprotective medications, and monitor hemodynamic and patency status. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.