Study on the relationship between the extent of runoff lesions under the knee and the patency of femoropopliteal artery stent in patients with diabetes

Objective To evaluate the impact of runoff score on the patency of femoropopliteal artery (FPA) stent in patients with type 2 diabetes mellitus with ultrasonography. Methods A retrospective review of a database of 127 patients with type 2 diabetes mellitus (127 limbs) undergoing femoropopliteal stents in Xuanwu Hospital from January 2016 to July 2018 was made. Demographic characteristics and possible related risk factors were recorded. The extent of FPA disease and the runoff lesions below the knee (anterior tibial artery, posterior tibial artery, and peroneal artery) were preoperative evaluated and regular followed-up by color Doppler ultrasonography (CDU). Femoropopliteal artery lesions were graded according to the Trans-Atlantic Inter-Society Consensus (TASCII), and the runoff lesions below the knee were scored according to the Society for Vascular Surgery (SVS). The patency and the predictors for in-stent restenosis were assessed using a Kaplan-Meier and Cox proportional hazards model. Results Follow up period ranged from 1 month to 24 months.The total patency rates at the 3, 6, 12, 24 months were 91.5%, 70.9%, 45.7% and 31.7%, respectively. Post-procedural runoff score according to SVS criteria: 1-3 scores in 45 limbs, 3.5-5 scores in 37 limbs, 5.5-7 scores in 34 limbs, 7.5-10 scores in 11 limbs. The median runoff score was 4.Patients were stratified according to runoff scores (score ≤4 and >4 groups), and the difference of the patency rates between the two groups was statistically significant by Kaplan-Meier analysis and Log-rank test (χ2=10.825, P=0.001). The runoff score affected patency significantly on COX analysis (RR=1.155, P=0.006, 95%CI: 1.042-1.281). Conclusions Compromised runoff negatively affects the patency of FPA stent. High post-procedural runoff score is a main risk factor related to loss of patency. CDU is a reliable method for monitoring patients with femoropopliteal stenting. Key words: Ultrasonography; Diabetes; Femoropopliteal artery; Runoff score; Stent