Outcomes of isolated inframalleolar interventions for chronic limb-threatening ischemia in diabetic patients

Background: Inframalleolar disease is present in many diabetic patients presenting with tissue loss. The aim of this study was to examine the patient-centered outcomes after isolated inframalleolar interventions. Methods: A database of patients undergoing lower extremity endovascular interventions for tissue loss (critical limb-threatening ischemia, Wound, Ischemia, and foot Infection [WIfI] stage 1-3) and a de novo intervention on the index limb between 2007 and 2017 was retrospectively queried. Those patients with isolated inframalleolar interventions on the dorsalis pedis and medial and lateral tarsal arteries were identified. Patients with concomitant superficial femoral artery and tibial interventions were excluded. Intention-to-treat analysis by patient was performed. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (AFS; survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump or interposition graft revision]) were evaluated. Results: There were 109 patients (48% male; average age, 65 years; 153 vessels) who underwent isolated inframalleolar interventions for tissue loss. All patients had diabetes, and 53% had chronic renal insufficiency (47% of these were on hemodialysis). The majority of the patients had WIfI stage 3 disease. Technical success was 81%, with a median of one vessel treated per patient. Thirty-four percent of interventions were a direct revascularization of the intended angiosome in the foot. The 30-day major adverse cardiovascular event rate was 0%. The majority of patients underwent some form of planned forefoot surgery (single digit, multiple digits, ray or transmetatarsal amputation). Wound healing at 3 months in those not requiring amputation was 76%. Predictors for wound healing were improved pedal runoff score (<7), absence of infection, direct angiosome revascularization, and absence of end-stage renal disease. Those in whom the primary wounds or the initial amputation site failed to heal ultimately underwent below-knee amputations. The clinical efficacy was 25% +/- 7% (mean +/- standard error of the mean) at 5 years. The 5-year AFS rate was 33% +/- 8%, and the 5-year freedom from major adverse limb events was 27% +/- 9%. On Cox proportional multivariate analysis, predictors for AFS were absence of significant coronary disease, postprocedure pedal runoff score <7 (good runoff), WIfI stage <3, and absence of end-stage renal disease. Conclusions: Inframalleolar intervention can be successfully performed in high-risk limbs with acceptable short-term results. However, long-term AFS remains poor because of the underlying disease process.