Where to Fenestrate in Aortic Dissection Type B? An Ex Vivo Study.

Background: Fenestration is a minimally invasive alternative for the treatment of acute symptomatic aortic dissections because it may quickly decrease the pressure gradient of the false lumen. It remains unclear where the optimal location of these fenestrations should be chosen. The purpose of this study was to study false lumen volume (FLV) after different fenestration strategies in porcine ex vivo models of aortic type B dissection.

Methods: An artificial dissection was created in ex vivo porcine aortas. A total number of 6 aortic dissection models were made. The dissection flap was divided in 3 equal parts; proximal, mid, and distal sections. In 3 models, a fenestration was made in the center of the proximal section of the dissection flap. In the 3 others in the center of the distal part of the dissection flap. The aorta was positioned in a validated in vitro circulatory system with physiological pulsatile flow. Volume measurements of true lumen volume and FLV were assessed with computed tomography.

Results: Performing a fenestration in the proximal part of the dissection flap resulted in FLV increase in 2 of the 3 models. Performing a fenestration in the distal part of the dissection flap resulted in FLV decrease in all 3 models. False lumen reduction was obtained significantly in the distally fenestrated models compared to the proximally fenestrated models (9.6 ± 3.5% vs. 0.7 ± 2.9%, P = 0.03).

Conclusions: In this ex vivo study, we showed that distal fenestration of the false lumen in aortic dissection will result in the largest false lumen reduction.