Comparison of lima-lad graft patency with bidirectional palpation test, transit time flowmeter(TTFM) and coronary CT angiography

Introduction: The most important factor determining mortality and morbidity after coronary artery bypass graft (CABG) surgery is graft patency. The LIMA-LAD anastomosis is the most crucial anastomosis because it's revascularizing the most important and large region of the heart, has superior long-term graft patency rates and is considered the gold standard for CABG. Therefore, ensuring the patency of the LIMA-LAD anastomosis is vital for both early and late outcomes. The bidirectional palpation test (BPT), developed in our clinic to assess graft patency, is a subjective test, yet it is simple and reliable. Additionally, transit time flow meter (TTFM) measurements have also been performed. In this study, the efficacy of BPT and the results of TTFM measurements were compared by examining graft patency through early-period coronary CT angiography (CCTA). Methods: The study was designed as a retrospective-prospective (hybrid) cohort study. Graft patency in the LIMA-LAD anastomosis of 73 patients was evaluated. The results of the bidirectional palpation test and TTFM measurements performed during CABG surgery were compared with contrast-enhanced CCTA taken in the early postoperative period. Results: Graft patency was statistically significantly higher in patients with a positive bidirectional palpation test compared to those with a negative test (p<0.001). Similarly, graft patency was significantly higher in patients with a mean flow of 10 mL/min or more compared to those with a mean flow below 10 mL/min (p=0.001). Conclusion: According to the statistical results obtained from the study data, there is a significant positive correlation between the bidirectional palpation test and the mean flow measured by TTFM. Additionally, both BPT and TTFM have shown accurately the intraoperative LIMA graft patency. These findings indicate that both tests can be reliably used in assessment of LIMA-LAD anastomosis. Keywords: Cabg, Graft Patency, LIMA-LAD Anastomosis, TTFM, Bidirectional Palpation Test