To investigate the impact of adequate lumen preparation on the 12-month primary patency rate of drug-eluting stents (DES) in patients with lower extremity arteriosclerosis obliterans （ASO） and to identify risk and protective factors for in-stent restenosis.

A retrospective cohort study was conducted on 141 patients who underwent DES implantation for ASO at the Department of Vascular Surgery of the First Affiliated Hospital of Chongqing Medical University between April 2022 and April 2024. According to post-percutaneous transluminal angioplasty (PTA) dissection grade [severe dissection is defined as type C or higher based on National Heart, Lung, and Blood Institute (NHLBI) criteria] and residual stenosis rate (severe stenosis is defined as ≥30%), the patients were categorized into an adequate preparation group (no severe dissection or severe residual stenosis; n=59) and an inadequate preparation group (n=82). DES primary patency at 12 months was assessed by color Doppler ultrasonography or angiography, defined as a peak systolic velocity ratio ≤2.4 on duplex ultrasound or angiographic stenosis <50%. Kaplan-Meier analysis was used to compare intergroup differences in DES patency rate and freedom from clinically driven target lesion revascularization (CD-TLR). Multivariate logistic regression analysis was employed to identify risk and protective factors for DES restenosis and to evaluate the risk contributions of post-PTA dissection and residual stenosis to DES restenosis.

Post-PTA, vascular dissection occurred in 94.3% (133/141) of treated limbs, among which 42.1% (56/133) were severe dissections, and severe residual stenosis was present in 44.0% (62/141) of limbs. Kaplan-Meier analysis revealed that the 12-month primary patency rate was significantly higher in the adequate preparation group than the inadequate group (HR=0.322, 95%CI: 0.132~0.789, P=0.013), while no significant difference was found in the rate of freedom from CD-TLR (HR=0.608, 95%CI: 0.187~1.937, P=0.407). Multivariate logistic regression analysis identified adequate lumen preparation (OR=0.228, 95%CI: 0.069~0.747, P=0.015) and Rutherford category 2~3 (OR=0.205, 95%CI: 0.058~0.725, P=0.014) as independent protective factors against DES restenosis. The patency rate in the subgroup with coexisting severe dissection and residual stenosis was significantly lower than that in the uncomplicated group (55.6% vs 89.8%, P<0.001), with a 7.067-fold increased risk of re-stenosis (95%CI: 2.424~20.602, P<0.001).

Adequate lumen preparation significantly improves the 12-month primary patency rate of DES. It, along with Rutherford category 2~3, serves as an independent protective factor against in-stent restenosis. Concurrent severe dissection and significant residual stenosis should be actively avoided during the procedure.