Aortic customize: a new alternative endovascular approach to aortic aneurysm repair using injectable biocompatible elastomer. An in vitro study.

Purpose: Aortic Customize is a new concept for endovascular aortic aneurysm repair in which a non polymerized elastomer is injected to fill the aneurysm sac around a balloon catheter. The aim of this in vitro study was to investigate the extent of aneurysm wall stress reduction by the presence of a noncompliant elastomer cuff.

Methods: A thin-walled latex aneurysm (inner radius sac 18 mm, inner radius neck 8 mm), equipped with 12 tantalum markers, was attached to an in vitro circulation model. Fluoroscopic roentgenographic stereo photogrammetric analysis (FRSA) was used to measure marker movement during six cardiac cycles. The radius of three circles drawn through the markers was measured before and after sac filling. Wall movement was measured at different systemic pressures. Wall stress was calculated from the measured radius (sigma = pr/2t).

Results: The calculated wall stress was 7.5-15.6 N/cm(2) before sac filling and was diminished to 0.43-1.1 N/cm(2) after sac filling. Before sac filling, there was a clear increase (P < .001) in radius of the proximal (range, 7.9%-33.5%), middle (range, 3.3%-25.2%), and distal (range, 10.5%-184.3%) rings with increasing systemic pressure. After sac filling with the elastomer, there remained a small, significant (P < .001) increase in the radius of the circles (ranges: 6.8%-8.8%; 0.7%-1.1%; 5.3%-6.7%). The sac filling reduced the extent of radius increase. The treated aneurysm withstood systemic pressures up to 220/140 mm Hg without noticeable wall movement. After the sac filling, there was no pulsation visible in the aneurysm wall.

Conclusions: Filling the aneurysm sac of a simplified in vitro latex model with a biocompatible elastomer leads to successful exclusion of the aneurysm sac from the circulation. Wall movement and calculated wall stress are diminished noticeably by the injection of biocompatible elastomer.