Lower Extremity Free Tissue Transfer in the Setting of Severe Medial Arterial Calcification: Limb Salvage Is Possible, But at What Cost?

Abstract

Medial arterial calcification (MAC) is emerging as a tool to predict adverse limb events, but its effects on microsurgery are unknown. This study evaluates the effects of MAC on microsurgical limb salvage outcomes. Patients receiving lower extremity free tissue transfer from 2011 through 2024 were reviewed. Radiographs were used to classify cases as no, moderate, or severe MAC. End points included major amputation, unscheduled surgical reintervention, postoperative revascularization, major adverse limb events, defined as the composite of major amputation or surgical reintervention, and survival. Among 320 cases, 12 (3.8%) had moderate and 32 (10.0%) had severe MAC. The median follow-up was 22.2 months. On univariate analysis, patients with moderate or severe MAC demonstrated significantly higher rates of the following: flap complications (25.7% [no MAC], 33.3% [moderate MAC], and 56.3% [severe MAC] [ P = 0.033]), major adverse limb events (42.0%, 75.0%, and 84.4% [ P < 0.001]), surgical reintervention (41.3%, 66.7%, and 81.3% [ P < 0.001]), postoperative vascular intervention (6.9%, 8.3%, and 31.3% [ P < 0.001]), major amputation (12.0%, 25.0%, and 31.3% [ P = 0.009]), and 5-year mortality (5.4%, 8.3%, and 18.8% [ P < 0.001]). On multivariable analysis, severe MAC independently increased the odds of major adverse limb events ( P = 0.009) and unscheduled reintervention ( P = 0.015). Microsurgical free tissue transfer can achieve limb salvage in patients with severe MAC but is associated with significant morbidity, and more than 80% of cases will require additional surgical management. Microsurgeons should be aware of the association of MAC with adverse events.