Endovascular approaches to acute aortic type A dissection: a CT-based feasibility study.

BACKGROUND

Open graft replacement of the ascending aorta is the current treatment of choice for Stanford acute type A dissections. However, approximately 20% of patients are deemed unfit for open surgery. To determine if an endovascular option exists for this latter group of patients, we performed a computed tomography (CT)-based feasibility study.

METHODS

A cohort of consecutive patients presenting to the cardiovascular care unit (CVCU) for an acute Stanford type A aortic dissection between 2006 and 2009 was retrospectively analysed. Inclusion criterion was a high-quality preoperative angio-CT scan that could be analysed on a three-dimensional (3D) workstation. Numerous anatomical parameters of the dissection were studied, including the location and the length of the primary proximal entry tear. Finally, we determined which of the patients would have been potential candidates for an endovascular repair (stentgraft implantation).

RESULTS

A total of 102 patients were included in our study. The median distance of the primary entry tear to the closest coronary artery was 23 mm (range 0-128). The median true lumen and true + false lumen (total) diameters at the level of the entry tear was 38 mm (range 22-78) and 46 mm (range 28-93), respectively. The median length of the ascending aorta was 84 mm (range 40-130). An endovascular repair with a tubular stentgraft was deemed feasible in 37 patients. An additional eight patients were also candidates for a tubular endovascular repair but would have required a carotidecarotid cross over bypass. Finally, an arch-branched stentgraft could have been used in 13 patients to exclude an entry tear located in the arch.

CONCLUSION

Open repair of acute type A dissection is and remains the 'gold standard' of care. Our study demonstrates that approximately half the patients undergoing an open repair could potentially benefit from an endovascular repair. This new treatment option has not been evaluated to date.