Acute type A aortic dissection intimal tears by 64-slice computed tomography: A role for endovascular stent-grafting?

Aim. The goal of this study was to identify physical characteristics of primary intimal tears in patients arriving to the hospital alive with acute type A aortic dissection using 64-multislice computerized tomography (MSCT) in order to determine anatomic feasibility of endovascular stent-grafting (ESG) for future treatment. Methods. Radiology database was screened for acute type A aortic dissection since the time of acquisition of the 64-slice CT scanner and cross-referenced with surgical database. Seventeen patients met inclusion criteria. Images were reviewed for number, location, and size of intimal tears and aortic dimensions. Potential obstacles for ESG were determined. Results. Ascending aorta (29%) and sinotubular junction (29%) were the most frequent regions where intimal tears originated. Location of intimal tears in nearly 75% of patients was inappropriate for ESG, and 94% of patients did not have sufficient proximal or distal landing zone required for secure fixation. Only 71% of patients underwent surgical aortic dissection repair after imaging and 86% of entry tears detected on MSCT were confirmed on intraoperative documentation. Only one patient would have met all technical criteria for ESG using currently available devices. Conclusion. Location of intimal tear, aortic valve insufficiency, aortic diameter>38mm are major factors limiting use of ESG for acute type A dissection. Available stents used to treat type B aortic dissection do not address anatomic constraints present in type A aortic dissection in the majority of cases, such that development of new devices would be required.