A Systematic Review Aggregated Data and Individual Participant Data meta-Analysis of Spot Stenting in the Treatment of Lower Extremity Peripheral Arterial Disease

Background: The treatment of infrainguinal peripheral arterial disease often involves complex lesions requiring stent implantation. It is common knowledge that stent length is a negative pre-dictor for restenosis. We investigated the efficacy and safety of spot stenting for the treatment of femoropopliteal lesions.Methods: We carried out a systematic review for articles published by December 2021 regarding spot stenting in the treatment of peripheral arterial disease. Primary endpoints included primary patency (PP) and freedom from target lesion revascularization (TLR) 12 months postoperatively. We performed a meta-analysis of aggregate data for PP, TLR and tech-nical success and a subgroup analysis between devices dedicated to spot stenting and conven-tional devices. Following the individual participant data (IPD) extraction, we performed a 2 stage time to event IPD meta-analysis for PP and TLR. Plotting of hazard estimates was performed by applying the Epanechnikov Kernel function.Results: Five studies with 818 patients, 965 lesions and a mean lesion length of 169.2 mm were included. Chronic total occlusions comprised 51.7% of the treated lesions while, 80% of the lesions involved the popliteal artery. The pooled PP 12 months post-operatively is 80.72% (95% confidence interval [CI]: 77.67-83.45) (I2 = 36%), 95% prediction interval (PI) (67.94-89.00). The subgroup analysis between devices dedicated to spot stenting and conventional de -vices produced similar results of 80.93% (95% CI: 77.17-84.19) (I2 = 0%) and 80.30% (95% CI: 74.72-84.90) (I2 = 62%), respectively. The pooled TLR rate is 13.06% (95% CI: 10.69-15.86) (I2 = 53%). The pooled technical success rate is 98.77% (95% CI: 97.50-99.40) (I2 = 18%). The IPD meta-analysis produced statistically significant results favoring spot stenting over long stent-ing for both primary endpoints. Primary patency hazard ratio (HR) 2.04. (95% CI: 1.25-3.32) (I2 = 0%, t2 = 0). TLR, HR 1.97 (95% CI: 1.02-3.79) (I2 = 0%, t2 = 0). Plotting of hazard estimates produced diametrically opposite courses for the spot and long stenting curves. The hazards cross over at about 6 months, and at about 10 months when long stenting group faces the high -est risk for loss of patency, spot stenting hazard reaches near zero values. The curves for TLR portray similar findings.