Learning curves for cardiothoracic and vascular surgical procedures – a systematic review

Objectives. The aim of this systematic review is to evaluate the learning curve (LC) literature and identify the LC of cardiothoracic and vascular surgical procedures. Summary and background. The LC describes an observation that a learner's performance improves over time during acquisition of new motor skills. Measuring the LC of surgical procedures has important implications for surgical innovation, education, and patient safety. Numerous studies have investigated LCs of isolated operations in cardiothoracic and vascular surgeries, but a lack of uniformity in the methods and variables used to measure LCs has led to a lack of systematic reviews. Methods. The MEDLINE®, EMBASE™, and PsycINFO® databases were systematically searched until July 2013. Articles describing LCs for cardiothoracic and vascular procedures were included. The type of procedure, statistical analysis, number of participants, procedure setting, level of participants, outcomes, and LCs were reviewed. Results. A total of 48 studies investigated LCs in cardiothoracic and vascular surgeries. Based on operating time, the LC for coronary artery bypass surgery ranged between 15 and 100 cases; for endoscopic vessel harvesting and other cardiac vessel surgery between 7 and 35 cases; for valvular surgery, which included repair and replacement, between 20 and 135 cases; for video-assisted thoracoscopic surgery, between 15 and 35 cases; for vascular neurosurgical procedures between 100 and 500 cases, based on complications; for endovascular vessel repairs between 5 and 40 cases; and for ablation procedures between 25 and 60 cases. However there was a distinct lack of standardization in the variables/outcome measures used, case selection, prior experience, and supervision of participating surgeons and a range of statistical analyses to compute LCs was noted. Conclusion. LCs in cardiothoracic and vascular procedures are hugely variable depending on the procedure type, outcome measures, level of prior experience, and methods/statistics used. Uniformity in methods, variables, and statistical analysis is needed to derive meaningful comparisons of LCs. Acknowledgment and application of learning processes other than those reliant on volume–outcomes relationship will benefit LC research and training of surgeons.