Transit-Time Flow Measurement of Saphenous Vein Graft Used for Surgery of Acute Type A Aortic Dissection with Coronary Malperfusion

Purpose: Transit-time flow measurement (TTFM), consisting of pulsatility index (PI), mean graft flow, and diastolic filling, is mainly used as a bypass assessment for coronary artery disease (CAD). However, little was known about TTFM in the case of coronary malperfusion (CMP). This study aimed to clarify the difference in the results of TTFM between two different diseases. Methods: Between 2010 and 2020, 138 patients underwent aortic surgery and coronary artery bypass grafting (CABG) with vein grafts. Patients were divided into two groups: CMP (n = 26) and CAD (n = 27). Their results were compared. The primary endpoints were the results of TTFM. Secondary endpoints were the relation between TTFM and mortality, morbidity, and short-term patency in each group. Results: The PI in the CMP group was significantly higher than the other group (4.7 +/- 2.9 vs. 3.4 +/- 1.9, p = 0.04). There was no statistical significance in the other two elements. In both groups, the short-term graft patency, mortality, and morbidity but for cardiac tamponade did not significantly change depending on the TTFM results. Conclusions: Patients with CMP tended to have a higher PI than those with CAD. With additional CABG for aortic dissection, insufficient TTFM results did not necessarily mean poor short-term graft patency, complications, or case mortality.