This is a study from the Sorbonne University’s Thoracic and Cardiovascular Surgery Department group located at La Pitie-Salpetriere.
The study “Impact of transit-time flow measurement on early postoperative outcomes in total arterial coronary revascularization with internal thoracic arteries: a propensity score analysis on 910 patients” by Laali et al is remarkable because it is a relatively large comparative study, and not least because of the results it generated.
The aim of this study was to evaluate the impact of transit-time flow measurement (TTFM) on early postoperative outcomes in total arterial coronary revascularization.
A single-center retrospective analysis was conducted on 910 patients undergoing isolated total arterial coronary artery bypass grafting with internal thoracic arteries (ITAs) at our institution, between January 2017 and February 2020. Complete arterial revascularization with bilateral ITAs with a Y-configuration, or single ITA, was planned for all patients. According to the surgeon preference, TTFM was assessed in 430 patients (TTFM group). They were compared with 480 patients without TTFM assessment (no TTFM group). Primary end point was the occurrence of in-hospital major cardiac adverse events (MACE). A propensity score analysis with an inverse probability weighting approach was performed to control for selection bias.
TTFM was associated with longer cardiopulmonary bypass times (76.0 [62.0; 91.2] vs 79.0 [65.0; 94.0] min, P = 0.042). Six (1.4%) patients in the TTFM group versus no patient in the no TTFM group underwent intraoperative graft revision because of unsatisfying flow values (P = 0.011). MACE was significantly lower in the TTFM group (14, 3.3%) than in the no TTFM group (33, 6.9%, P = 0.014). At crude regression, TTFM was protective against MACE occurrence (odds ratios 0.46, 95% confidence interval 0.23–0.85, P = 0.016). Inverse probability weighting adjustment did not significantly displace P-values and odds ratios for MACE occurrence in the TTFM group 0.44, 95% confidence interval 0.28–0.69, P < 0.001.
Even if associated with longer cardiopulmonary bypass times, intraoperative graft flow measurement with TTFM reduces MACE occurrence and it should be recommended for graft evaluation in arterial coronary artery bypass grafting surgery.
Full article and citation
Laali M, Nardone N, Demondion P, D’Alessandro C, Guedeney P, Barreda E et al.
Impact of transit-time flow measurement on early postoperative outcomes in total arterial coronary revascularization with internal thoracic arteries: a propensity score analysis on 910 patients. Interact CardioVasc Thorac Surg 2022; doi:10.1093/icvts/ivac065.
This large comparative study compares the outcome for CABG patients with and without the use of Medistim TTFM.
Adding only 3 minutes extra cardiopulmonary (CPB) time (30 s per measurement) was enough to reduce the MACE prevalence to less than half of that without TTFM.
The authors explain that when the hospital was equipped with Medistim systems in 2015, half of the surgeons were not convinced of the usefulness of TTFM, and they never used it. After being presented with the results from the study, all the surgeons eventually adopted TTFM for graft evaluation. Consequently, it is no longer possible to perform a randomized TTFM study at this hospital.
Another interesting change post-study was that the teams have started performing TTFM for each anastomosis while on clamp. They find this measurement extra useful with anastomoses on the lateral or inferior wall, with multiple sequential grafts.
Measurements during ‘cross-clamp on’ can help check the integrity of anastomosis. This new practice seems to have made the surgeons more confident in the quality of surgery.
The most relevant outcomes from the study are summarized in the table attached. (Picture 1)