Clinical Impact and Predictors of the Slow-Flow Phenomenon after Endovascular Treatment of Infrapopliteal Lesions Using the Crosser Catheter in Patients with Critical Limb Ischemia.

Purpose: To determine the clinical impact and predictors of slow flow after endovascular treatment (EVT) using the Crosser catheter for debulking infrapopliteal lesions associated with critical limb ischemia.

Materials And Methods: This retrospective study included 65 patients with critical limb ischemia (70 limbs, 90 infrapopliteal lesions), who underwent EVT using the Crosser catheter between November 2011 and February 2017. The Crosser catheter was used when the balloon catheter could not be passed through the lesion or could not be dilated sufficiently. Slow flow was evaluated after atherectomy using Crosser and was defined as delayed antegrade flow to the foot (total number of cine frames >35).

Results: Following atherectomy, slow flow developed in 37 infrapopliteal lesions (41.1%). Despite secondary treatment, slow flow persisted in 29 of 37 lesions (78%). After atherectomy using the Crosser catheter, the balloon could be passed through the lesion in all cases. The wound healing rate at 1 year after EVT (overall, 67.8%) was significantly poorer in the presence of slow flow (rate with vs. without slow flow, 45.3% vs. 84.4%, respectively; P = .006), especially among patients with stage ≥3 baseline wound, ischemia, and foot infection. The active length of the Crosser catheter was a predictor of slow flow (odds ratio, 1.05; 95% confidence interval, 1.03-1.08; P < .001), with an optimal cutoff of 100 mm.

Conclusions: Slow flow is associated with a poorer wound healing rate at 1 year, especially for patients with severe baseline ischemia. To reduce the risk of slow flow, the active length of the Crosser catheter should be kept at <100 mm.