Date of Award

January 2026

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Cassius I. Chaar

Abstract

Lower extremity revascularization (LER) is central to the management of peripheral arterial disease (PAD), especially in patients with the most severe form of disease, chronic limb threatening ischemia (CLTI). Conduit selection is critical for durability of infrainguinal bypass with single segment greater saphenous vein (SSGSV) now widely accepted as the gold standard conduit. Published studies of initial LER have largely focused on the durability of the procedures by examining major amputation and reintervention as primary outcomes in addition to mortality. Even though reinterventions are common after LER, differences in the magnitude and frequency of reintervention after initial revascularization have not been elucidated. The objective of this thesis is to analyze trends regarding index infrainguinal LER utilization and provide a comprehensive comparative analysis of contemporary surgical outcomes of various LER strategies focusing on reintervention frequency and magnitude. This thesis utilizes two registries of the Vascular Quality Initiative (VQI), the peripheral vascular intervention (PVI) registry recording endovascular LER since 2010, and the infrainguinal bypass (INFRA) registry recording open bypasses since 2003. Procedures performed for aneurysmal disease were excluded from both registries. Only patients with a non-emergent, infrainguinal index LER recorded for claudication or CLTI through a reporting center participating in both PVI and INFRA registries were included. Trend analysis was performed using a sample of index LER from 2011-2024. A comparative analysis was performed on patients with an index LER occurring from 2016-2024. Patient characteristics, procedural details, and perioperative outcomes were compared between patients treated with index PVI, bypass with SSGSV conduit, and bypass with an alternative conduit. Long-term outcomes were investigated with Kaplan-Meier analysis to report 1-year event estimates. Reintervention events for each patient were quantified using subsequent registry records. Multivariable regression analysis was performed to identify factors associated with reintervention frequency and overall mortality. The trend analysis included 120,762 patients, finding that the proportion of endovascular procedures among total index LER has significantly increased over the study period from 71.6% in 2011 to 86.8% in 2024 (P<0.001). This significant upward trend in an ‘endovascular-first’ approach was consistent among four patient subgroups with the largest magnitude among patients with CLTI undergoing procedures involving tibial revascularization. The outcome analysis included 94,621 patients (85% PVI; 8% SSGSV bypass; 6% Other bypass). Patients treated with index PVI were older, and were more likely to be female, non-white patients and non-ambulatory patients with larger proportions of most medical comorbidities compared to patients treated with an index bypass. Patients treated with Other Conduit bypass experienced higher in-hospital mortality rates compared to those treated with PVI among claudication patients (0.7% vs 0.3%, P=0.009) and CLTI patients (1.6% vs 1.1%, P=0.007). Among claudication patients, there was no difference in overall survival or amputation-free survival between PVI patients and either bypass group. Among CLTI patients, those treated with index PVI experienced worse overall survival, amputation-free survival and major adverse limb event-free survival compared to those in both bypass groups. One year risk of major amputation or death was highest among PVI patients (31.3%[30.8-31.7%]), followed by Other Conduit bypass (28.2%[26.6-29.8%), then SSGSV bypass (21.1%[19.8-22.3%]). Among both claudication and CLTI patients, PVI patients experienced both higher cumulative ipsilateral reintervention, and higher reinterventions per patient-year compared to both bypass groups. Multivariable regression revealed that both SSGSV and Other Conduit bypass approaches were independently associated with a lower incidence of reintervention events per patient-year (IRR=0.74[0.71-0.79] and IRR=0.75[0.71-0.79], respectively). Factors independently associated with a higher reintervention frequency included CLTI (IRR=1.28[1.24-1.33]), diabetes (IRR=1.04[1.01-1.07]), chronic anticoagulation (IRR=1.05[1.02-1.09]), urgent compared to elective procedures (IRR=1.04[1.01-1.08]) and tibial involvement compared to strictly femoropopliteal procedures (IRR=1.03[1.00-1.06]). The ‘endovascular-first’ approach to infrainguinal LER is becoming more prevalent. Depending on the indication for revascularization, patients who undergo a bypass first approach experience either similar or improved amputation free survival compared to patients who undergo an index endovascular procedure. Patients undergoing a bypass-first approach experience less incidence of reintervention and a lesser frequency of reintervention compared to those treated with index PVI, with index LER strategy being independently associated with lower reintervention frequency.

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This is an Open Access Thesis.

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