B. N. Arnold1, D. C. Thomas1, V. Bhatnagar1, J. D. Blasberg1, Z. Wang2, D. J. Boffa1, F. C. Detterbeck1, A. W. Kim3 1Yale University School Of Medicine,Section Of Thoracic Surgery,New Haven, CT, USA 2Yale University School Of Medicine,School Of Public Health,New Haven, CT, USA 3University Of Southern California,Division Of Thoracic Surgery,Los Angeles, CA, USA
Introduction: Robot-assisted thoracoscopic (RobAT) lobectomy has been shown to be a safe approach to pulmonary lobectomy. There is a learning curve associated with integrating the robotic platform into thoracic surgery. This study sought to define, mathematically, the learning curve for RobAT lobectomy.
Methods: All patients undergoing RoBAT lobectomy at a single academic medical center from 2010 through 2016 were considered. Covariates included patient demographics, comorbidities, operating time (ORT), length of hospital stay (LOS), estimated blood loss (EBL), and post-operative complications. A cumulative sum (CUSUM) analysis of ORT was performed to identify three distinct phases of the learning curve. Procedures converted to open were omitted from the analysis, but the number of conversions within each phase of RoBAT lobectomy was tallied.
Results: 101 patients met criteria for inclusion. CUSUM analysis identified two inflection points which stratified the population into three phases: cases 1-22, cases 23-63, and cases 64-101. There was a statistically significant difference in operating time and estimated blood loss between phases 1 and 2 (ORT p<0.05, EBL p=0.016), and between phases 1 and 3 (ORT p<0.05, EBL p=0.006). There was no difference in ORT or EBL between phases 2 and 3. There was no statistically significant difference in comorbidities, chest tube duration, LOS, or post-operative complications across the learning curve. Conversion rates in phase 1, 2, and 3 were 12% (3/25), 9% (4/45), and 3% (1/39), respectively. Of these conversions, 2/8 were emergent and occurred in phases 1 and 2.
Conclusion: Based on ORT, the learning curve for RoBAT lobectomy appears to be 22 cases, with mastery achieved after 63 cases. Differences in length of stay, chest tube duration, conversion rate, or complication rate were not observed during the learning phase. Other factors not measured in this study may play a role in the learning process and warrant further study.
