Learning curves in minimally invasive esophagectomy: A systematic review and evaluation of benchmarking parameters.

BACKGROUND:Minimally invasive techniques are increasingly used in the treatment of esophageal cancer. The learning curve for minimally invasive esophagectomy is variable and can impact patient outcomes. The aim of this study was to review the current evidence on learning curves in minimally invasive esophagectomy and identify which parameters are used for benchmarking. METHODS:A search of the major reference databases (PubMed, Medline, Cochrane) was performed with no time limits up to February 2020. Results were screened in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if an assessment of the learning curve was reported on, regardless of which (if any) statistical method was used. RESULTS:Twenty-nine studies comprising 3,741 patients were included. Twenty-two studies reported on a combination of thoracoscopic, hybrid, and total minimally invasive esophagectomy, 6 studies reported robotic-assisted minimally invasive esophagectomy alone, and 1 study evaluated both robotic-assisted minimally invasive esophagectomy and thoracoscopic esophagectomies. Operating time was the most frequently used parameter to determine learning curve progression (23/39 studies), with number of resected lymph nodes, morbidity, and blood loss also frequently used. Learning curves were found to plateau at 7 to 60 cases for thoracoscopic esophagectomy, 12 to 175 cases for total and thoracoscopic/hybrid esophagectomy, and 9 to 85 cases for robotic-assisted minimally invasive esophagectomy. CONCLUSION:Multiple parameters are employed to gauge minimally invasive esophagectomy learning curve progression. However, there are no validated or approved sets of outcomes. Further work is required to determine the optimum parameters that should be used to ensure best patient outcomes and required length of proctoring.