Prediction of Aortic-Related Complications after Acute Type A Dissection Surgery with CT-based Volumetric Measurements

Evangelos Papadimas ¹, Jasmine Ge ², Siew-Pang Chan ¹, Bernard Wee ¹, Julian Wong ¹, Kristine Teoh ¹, Theo Kofidis ¹, Vitaly Sorokin ¹

¹ National University Hospital, Singapore, Singapore; ² National University of Singapore, Singapore, Singapore;

Date, time and location: 2018.05.25 15:30, Exhibition area, 1st Floor. Zone – C

Abstract

Objectives: The aim of this study is to evaluate the predictive power of postoperative computed CT aortic volumetric measurements for the occurrence of aortic complications after Type A aortic dissection.

Methods: This was a retrospective analysis of 165 patients with Type A dissection from the adult cardiac surgery database of a single institution from 2001 to 2015. Patients included in the study underwent ascending aorta replacement with a postoperative follow-up of at least 12 months. CT-based volumetric measurements included total lumen volume (total-L), true lumen volume (TL) and false lumen volume (FL). Mortality, cardiovascular complications were assessed with the generalised structure equation model.

Results: Patients with postoperative aortic complications had a significantly higher FL volume (p=0.022; OR: 1.02) and total-L volume (p=0.050; OR: 1.01) on the first postoperative scan. The odds of having aortic complications was raised by 1% with a 1cm3  increase in total-L volume, and 2% with a 1cm3  increase in FL volume. Furthermore, patients with late complications had lower TL:FL ratio in comparison to the uncomplicated group at the second postoperative scan. The TL:FL ratio in the complicated group was constantly below 1 in both the first scan (0.815 ± 0.238) and the second scan (0.813 ± 0.324). The TL:FL ratio was at 5% level of significance to predict late aortic complications.

Conclusions: Post-operative computed tomography volumetric measurements could be an effective tool to predict postoperative aortic complications in acute Type A dissection patients. In the complicated group, 3 months after operation the total-L volume and FL volume demonstrate significant expansion compared to corresponding volumes in the uncomplicated group. Increase in FL by 1cm3 correlates with 2% increase in risk for subsequent development of aortic complications. Complicated patients' volumetric analysis trends lower TL:FL ratio, associated with ratio less than 1. This group of patients needs to be considered for closer follow up and early intervention to prevent life threatening complications.