Comparing Sac Embolization and Inferior Mesenteric Artery Embolization in Preventing Type II Endoleaks Post-EVAR

To compare the efficacy of sac embolization (SACE) versus inferior mesenteric artery embolization (IMAE) in preventing persistent Type II endoleaks (pT2EL) and promoting aneurysmal sac shrinkage following endovascular aneurysm repair (EVAR) in high-risk patients.

From January 2018 to December 2022, 273 EVAR patients were screened, and 75 with patent IMA and high T2EL risk were included. Patients were divided into 2 groups: EVAR with IMAE (33 cases) and EVAR with SACE (42 cases). The primary endpoint was the incidence of pT2EL. Secondary endpoints included sac enlargement, shrinkage, and T2EL-related reintervention. Kaplan-Meier analysis and multivariate regression were used for comparisons.

SACE was associated with a significantly lower incidence of pT2EL than IMAE (2.4% vs 21.2%, p=0.007; HR: 0.140, 95% CI: 0.034-0.578) and a higher rate of sac shrinkage (>5 mm reduction) (83.3% vs 57.6%, p=0.005; HR: 2.272, 95% CI: 1.286-4.014). Sac enlargement (>5 mm) occurred only in the IMAE group (6.1%, p=0.097). SACE required less contrast use (113.7 ± 24.5 vs 140.5 ± 29.6 mL, P < 0.001) and exhibited a trend toward fewer reinterventions. No ruptures or AAA-related deaths occurred in either group.

SACE is more effective than IMAE in preventing pT2EL and promoting sac shrinkage in high-risk EVAR patients. These results support SACE as the preferred adjunctive strategy, warranting further multicenter studies with longer follow-up to confirm its benefits and optimize techniques.Clinical ImpactThis study provides comparative evidence on two adjunctive techniques used during EVAR for high-risk patients. Sac embolization (SACE) demonstrated a lower incidence of persistent type II endoleaks and a higher rate of aneurysm sac shrinkage compared with inferior mesenteric artery embolization (IMAE), with reduced contrast use and comparable safety. These findings suggest that SACE may offer a more effective and practical approach for type II endoleak prevention and sac regression, potentially improving long-term outcomes and procedural efficiency in EVAR practice.