RS18 - PTFE Cuff Fenestration Reinforcement Demonstrates Low Endoleak Rates in PMEGs, Independent of Bridging Stent Type

Objectives: Both standard and low-profile endografts have been utilized for physician-modified endografts (PMEGs) to treat complex aortic aneurysms; however, recent multi-institutional data suggest that low-profile devices are associated with type IIIc endoleak rates as high as 15% at 20-month follow-up. Early demonstrations of PMEG modifications, including fenestration reinforcement with PTFE cuffs, have proposed a possible remedy to these elevated endoleak rates. This analysis evaluates a single-center’s experience with PTFE cuff reinforcement for PMEG fenestrations.

Methods: All PMEGs performed at a single institution between 2016-2025 were retrospectively reviewed. Each PMEG included fenestrations reinforced with a PTFE cuff and embolization coil. Primary outcomes included target vessel-related endoleaks (Ic and IIIc) and endoleak-related reintervention, evaluated both per-patient and per-fenestration. Bridging stent type (iCAST versus VBX) was evaluated as a potential modifier of outcomes, with secondary outcomes including patency and target vessel instability (TVI). Rates were reported using Kaplan-Meier estimates.

Results: Overall, 229 low-profile PMEGs (847 PTFE cuffs) were included. The median age was 76 years and patients were primarily white (89%) and male (72%). The majority of cases were done electively (82%) for juxtarenal aneurysms (65%). The median aneurysm diameter at time of repair was 62mm, and 80% included four or more target vessel fenestrations. Through two years, 26% (N=42) of patients underwent an aneurysm- or PMEG-associated reintervention; of these, nearly half (N=21; 15% of all patients) were endoleak-related (Table I). The most common indication for endoleak-related reintervention was sac expansion from type II endoleaks (8.9%). Type Ic and IIIc endoleaks occurred in 2.2% and 1.1% of patients, respectively, corresponding to per-fenestration rates of 0.6% and 0.1% among PTFE-cuffed fenestrations.

Bridging stents included 358 iCAST and 489 VBX and, despite differing significantly by vessel, no significant differences were observed in two-year patency (97.9% vs. 98.8%; Table II), stenosis/occlusion (2.1% vs. 2.0%), or stent-related reinterventions (1.0% vs 1.3%) (all P>.05). No difference was noted between stent types regarding cumulative Ic or IIIc rates (iCAST: 0.7% vs. VBX: 1.0%), nor in freedom from target vessel instability at two years (98.3% vs. 98.6%) (all P>.05).

Conclusions: PMEG modification with individual fenestration reinforcement using a PTFE cuff and embolization coil demonstrates effective fenestration sealing with low rates of target vessel-related endoleaks. Bridging stent choice does not appear to be a primary determinant of TVI, endoleaks, or reinterventions, potentially underscoring the importance of fenestration modifications. These findings suggest the value of utilizing this technique for PMEG customization in low-profile devices.