Type Ib Endoleak After Endovascular Aortic Repair: Occurrence Rate, Management Strategies, and Outcomes. A Systematic Review and Meta-Analysis

Purpose: To assess the available evidence on the management and outcomes of type Ib endoleak (TIbEL) after endovascular aortic repair (EVAR). Materials and methods: A systematic literature search (MedLine, Web of Science, Scopus, and Cochrane Library) was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO registration number: CRD420261304103). Studies reporting at least five cases of TIbEL after EVAR were included. Primary outcomes were technical success (TS), clinical success (CS), and early mortality (≤30 days). Meta-analyses of proportions were performed using a random-effects model. Results: Thirty-seven studies including 474 patients with 516 TIbEL were analyzed. The estimated occurrence rate of TIbEL was 3.7% (95%CI 2.9-4.5). The weighted mean time from EVAR to TIbEL diagnosis was 39.8 months (95%CI 33.1-46.5). The most frequently adopted treatment approaches were distal stent-graft extension in the common iliac artery (40.9%; 95%CI 23.6-58.2; TS 96.0%), stent-graft extension to the external iliac artery with internal iliac artery embolization (25.9%; 95%CI 15.5-36.4; TS 92.5%), iliac branch endograft (16.3%; 95%CI 2.5-30.2; TS 96.6%), and late open conversion (14.5%; 95%CI 7.3-21.7; TS 90.1%). Overall TS and CS rates were 96.4% (95%CI 94.4-98.5) and 95.5% (95%CI 93-98), respectively. The estimated intraoperative mortality was 3.2% (95%CI 1.3-5.2), while early mortality was 3.4% (95%CI 1.5-5.4). The estimated recurrence rate of TIbEL during follow-up (mean 35.8 months) was 3.3% (95%CI 1.3-5.4). Conclusion: The available evidence indicates that endovascular treatment is the most commonly adopted approach and is associated with high TS.