Safe implementation of robotic-assisted minimally invasive direct coronary artery bypass: application of learning curves and cumulative sum analysis

Abstract

Learning curves are inevitably encountered when first implementing an innovative and complex surgical technique. Nevertheless, a cluster of failures or complications should be detected early, but not deter learning, to ensure safe implementation. Here, we aimed to examine the presence and impact of learning curves on outcome after robotic-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB). Methods:A retrospective analysis of the first 300 RA-MIDCAB surgeries between July 2015 and December 2020 was performed. Learning curves were obtained via logarithmic regression for surgical time.Cumulative sum (CUSUM) analysis was performed for (I) major complications including MI, stroke, repeat revascularization, and mortality, and (II) other complications, including prolonged ventilation, pneumonia, pleura puncture, lung herniation, pericarditis, pleuritis, arrhythmia, wound complications, and delirium. Expected and unacceptable rates were set at 12% and 20%, respectively, for major complications, and at 40% and 60% for other complications, based on historical data in conventional coronary artery bypass grafting (CABG). Results: Demographic characteristics did not differ between terciles, except for more smokers in the first tercile, and less hypercholesterolemia and more complex procedures in the third tercile. The mean surgical time for all operations was 258±81 minutes, ranging from 127 to 821 minutes. A learning curve was only observed in the first tercile. Subgroup analysis revealed that this learning curve was only observed for procedures consisting of single internal mammary artery (SIMA) with 1 or 2 distal anastomoses but not with bilateral internal mammary arteries (BIMA) or more than 2 distal anastomoses. CUSUM analysis showed that the cumulative rate of major and other complications never crossed the lines for unacceptable rates. Rather, the lower 95% confidence boundary was crossed after 50 cases, indicating improvement in safety. Conclusions:These results suggest that integration of RA-MIDCAB in the surgical landscape can be safely achieved and complication rates can quickly be reduced below those expected in traditional CABG.Collective experience plays a key role in overcoming the learning curve when more complex procedures and cases are introduced.

Hybrid coronary revascularization versus percutaneous coronary intervention: A systematic review and meta-analysis

“…However, it is likely that a similar volume-outcome relationship exists for HCR, as has previously been demonstrated for other technically challenging procedures such as off-pump CABG [26] . Clearly, the use of the robotic system for harvesting of the graft(s) and performance of the anastomosis through a mini-thoracotomy are technically demanding, and this has been reflected in the presence of learning curve to acquire experience with this procedure [27] .…”

Minimally invasive left internal mammary artery harvesting techniques during the learning curve are safe and achieve similar results as conventional LIMA harvesting techniques

“…Their results also described that about 50 surgeries are required to overcome the learning curve and get the desirable results of RACAB. They also achieved the most improvement in the surgical times during the first 100 cases [ 30 ]. We believe after performing 42 MIDCAB and 32 RACAB procedures we have not overcome the learning curve yet and the learning curve is not as short as 20 procedures.…”

Robot-assisted vs. conventional MIDCAB: A propensity-matched analysis

“…In discordance with previous evidence, we did not observe longer operation times in the RA group despite including the learning curve. This could be explained by a sophisticated high-quality virtual and dry/wet lab training of the team that must be completed before the start of the robotic program, followed by a support of experienced mentor physically present in the operating room during the first few cases ( 8 , 9 ).…”

“…With an advancement of robotic surgical technologies, the MIDCAB has been increasingly performed with the robotic assistance during LITA harvest (RA-MIDCAB) or even as a totally endoscopic procedure (TECAB) ( 8 , 9 ). This strategy has been repeatedly compared with standard full sternotomy approach yielding superior short-term results ( 10 – 12 ).…”