Evaluating the learning curves and surgical outcomes of natural orifice specimen extraction surgery (NOSES) for colorectal cancer: A retrospective analysis from a National Registry.

Abstract

Proficiency acquisition in minimally invasive surgery requires rigorous evaluation of learning curves. While natural orifice specimen extraction surgery (NOSES) offers enhanced minimally invasive potential compared to conventional laparoscopy, comprehensive analyses of procedure-specific learning trajectories remain underexplored. This study quantitatively evaluates the learning curves and associated clinical outcomes for three NOSES procedures in colorectal cancer (CRC): eversion resection, extraction resection and resection extraction. We screened multiple patient cohorts from the NOSES national database between May 2010 and February 2022. A total of fifteen patient cohorts were included, with five patient cohorts for each NOSES procedure. The learning curve was determined based on the analysis of operation time and blood loss. Cumulative sum (CUSUM) analysis was applied to identify the learning curve turning points (TP). The pooled mean CUSUM curve (for operation time) of the eversion-resection technique group showed that TP was 21 cases, 28 cases and 22 cases of the extraction-resection and resection-extraction technique groups, respectively. The pooled mean CUSUM curve (for blood loss) of the eversion-resection technique group showed that TP was 18 cases and 24 cases and 17 cases of the extraction-resection and resection-extraction technique groups, respectively. Overall, surgical outcomes post-TP were superior to pre-TP. The surgical outcomes improved with the increase in surgical experience. We determined the evolving trend of the three learning curves for CRC-NOSES procedures. The demonstrated association between surgical experience and outcome optimization underscores the importance of structured training programmes to facilitate safe adoption of these advanced techniques.