RS02 - Outcomes of infrainguinal bypass with spliced veins in patients with chronic limb threatening ischemia

Objectives: Single segment greater saphenous vein (ssGSV) is the gold standard conduit for infrainguinal bypass in chronic limb-threatening ischemia (CLTI). Spliced vein bypass (SVB) is an alternative conduit, but its outcomes have not been well characterized. Moreover, the impact of the number of spliced segments on outcomes remains unclear. This study examines the outcomes of SVB with 2 vein segments (2sSVB) and 3 vein segments or more (3sSVB) compared to ssGSV for infrainguinal bypass.

Methods: The Infrainguinal Bypass Vascular Quality Initiative (VQI) module (2003-2025) was reviewed for patients treated for CLTI with ssGSV, 2sSVB, and 3sSVB. Propensity matching (3:1) was performed to compare 2sSVB (cohort 1) and 3sSVB separately to ssGSV (cohort 2) adjusting for baseline characteristics including indication, urgency, and bypass configuration. Perioperative and long-term outcomes were reported, and the primary outcome was MALE-free survival.

Results: A total of 46,945 infrainguinal bypass procedures (51.5% ssGSV N = 24,185; 4.1% 2sSVB N = 1,906; 0.42% 3sSVB N = 197) were analyzed. There were significant baseline differences in characteristics. After matching, there were 2 comparison groups (5,017 ssGSV vs 1,681 2sSVB and 525 ssGSV vs 175 3sSVB) with similar characteristics. Splicing veins incrementally increased operating time by 64 min (2sSVB) and 84 min (3sSVB). Estimated blood loss also incrementally increased by 91ml (2sSVB) and 114ml (3sSVB) as well as corresponding mean number of pRBC transfusions. There was a trend towards higher cardiac complications that reached statistical significance only for 2sSVB. Perioperatively, 2sSVB had higher rates of return to OR for thrombosis (4.9% vs 3.7%, p = 0.031) compared to ssGSV and a similar trend was noted for 3sSVB. Patients undergoing 3sSVB had a 3-fold increase in inpatient mortality (3.4% vs 1.0%, p = 0.033) compared to ssGSV. Over the mean follow-up of 406 days, 2sSVB patients had statistically significant higher cumulative rates of major amputation, reintervention, and mortality with outcomes of patients treated with 3sSVB showing similar trends. KM curve shows significantly lower MALE-free survival for 2sSVB (p < 0.001) and 3sSVB (p = 0.041) compared to ssGSV. The 1-year estimates of MALE or death were 29.1%-31.2% (ssGSV 1, 2), 38.0% (2sSVB) and 49.3% (3sSVB).

Conclusions: Splicing veins for infrainguinal bypass to treat CLTI is associated with incremental operative time, blood loss, and perioperative complications compared to ssGSV. MALE-free survival decreased with increasing number of spliced vein segments. Comparison of SVB to other alternative conduits is needed to better define its role in limb salvage.