S. Banerjee1, A. Das1, H. Zimmerman1, R. Jennings1, R. Boova1 1Temple University Hospital,Department Of Cardiothoracic Surgery,Philadelpha, PA, USA
Introduction:
Surgical aortic valve replacement (SAVR) may be associated with unanticipated intraoperative aortic pathology that is not identified by routine pre-operative evaluation. Such findings may alter the conduct of SAVR. Pre-operative multidetector computed tomography (MDCT) was adopted to mitigate unexpected intraoperative aortic findings.
MDCT is integral in preoperative sizing for transcatheter aortic valve replacement (TAVR) sizing. As TAVR emerged as an alternative to SAVR, our institutional TAVR MDCT protocol was implemented in pre-operative SAVR assessment to avoid duplicate MDCT, if findings resulted in pathology more amenable to TAVR than SAVR.
The purpose of this study is to determine if our institutional TAVR MDCT accurately predicts aortic valve prosthesis size. The secondary objective is to determine if there is a trend towards over- or under-sizing, if MDCT is not consistent with implant size.
Methods:
Between July 2012 and July 2017, 102 patients who underwent surgical aortic valve replacement had preoperative aortic valve sizing by MDCT. The aortic annulus diameter calculated using MDCT was compared to intraoperative valve sizing during SAVR. Implanted valve size within 1 mm of the MDCT calculated size was regarded as accurate in predicting valve size. If the implanted valve was outside the 1 mm range, it was classified as either smaller or larger. This was done because valves used in SAVR are manufactured in 2 mm increments. To evaluate if MDCT accuracy was affected by aortic valve annulus size, we stratified the valve diameters based on MDCT measurements into categories: 17.8-19.9, 20- 21.9, 22-23.9, 24-25.9, and >26mm. Statistical analysis was performed using SPS software and paired t-test was used to evaluate whether the results were statistically significant.
Results:
Forty-one (40.2%) of the 102 patients studied had MDCT aortic valve measurements that were within 1mm of implant size. Implanted valves were smaller than MDCT calculation in 40 patients (39.2%) and were larger in 21 patients (20.6%). MDCT measurements remained inconsistent with intraoperative sizing regardless of aortic annulus diameter. The variance between MDCT annulus measurements and intraoperative sizing was statistically significant, p value less than 0.0005, as determined by paired t-test.
Conclusion:
Preoperative aortic annulus measurements by MDCT differed substantially from intraoperative sizing. Furthermore, there was no trend towards over- or under-sizing. These results may impact preoperative planning for patients undergoing SAVR if MDCT is utilized for preoperative planning. The implication of this information on preoperative TAVR planning is indeterminate and may warrant further investigation.
