Surgical outcomes of ipsilateral in-situ versus contralateral or free internal thoracic artery grafting in dialysis-dependent patients with upper-extremity arteriovenous fistulas undergoing coronary artery bypass grafting

OBJECTIVE: The use of in-situ internal thoracic artery (ITA) grafts ipsilateral to upper extremity arteriovenous fistulas (UE-AVFs) during coronary artery bypass grafting (CABG) in dialysis-dependent patients raises concerns of coronary steal and compromised graft perfusion. However, the clinical significance of ITA-AVF laterality remains uncertain. METHODS: We retrospectively analyzed dialysis-dependent patients who underwent CABG between February 2015 and December 2023 at two institutions. Patients with non-UE-AVF access, total vein grafting, or composite vein-artery configurations were excluded. The final cohort (N = 122) was divided into two groups: ipsilateral in-situ ITA grafts (N = 66) and contralateral in-situ or free ITA grafts (N = 56). Primary outcome was the incidence of major adverse cardiovascular and cerebrovascular events (MACCE); secondary outcomes included perioperative complications, hemodialysis-induced ischemia, and 3-year survival. RESULTS: Baseline and operative characteristics were largely comparable between groups. Perioperative outcomes, including surgical site infection, 30-day mortality, and prolonged ventilation, showed no significant differences. Over a median follow-up of 2.4 years, MACCE occurred in 44% of patients (39% ipsilateral vs. 50% contralateral/free ITA; p = 0.24), with no significant differences in 3-year mortality (29% vs. 21%; p = 0.352). Multivariable analyses showed no association between ITA-AVF laterality and MACCE (aOR 0.68, p = 0.31) or 3-year mortality (aHR 1.56, p = 0.291). CONCLUSIONS: In this modestly sized retrospective cohort, ipsilateral in-situ ITA grafting was not associated with significantly worse perioperative or long-term outcomes. Our findings should be interpreted as hypothesis-generating, and larger multicenter studies are needed to more definitively evaluate the safety of this grafting strategy in dialysis-dependent patients with UE-AVFs.