Comprehensive Evaluation of the Learning Curve for Peroral Endoscopic Myotomy

Peroral endoscopic myotomy (POEM) is a minimally invasive endoscopic surgical procedure that is effective in treatment for spastic esophageal motility disorders. However, little is known about the learning curve for endoscopists. We aimed to evaluate the effects of various factors on the POEM learning curve.

We performed a retrospective study of 1346 patients who underwent POEM for achalasia at Shanghai Zhongshan Hospital in China from August 2010 through July 2015. We used risk-adjusted cumulative sum and moving average methods to evaluate outcomes. The primary outcome was a composite of technical failure and adverse events. Secondary outcomes included procedure time and the composite outcome of technical failure, adverse events, and clinical failure of the first 192 cases performed by only the original, training surgeon.

The primary composite outcome occurred in 54 (4%) of the 1346 patients: 10 technical failures and 44 adverse events. This composite outcome was independently associated with the case number (P = .010), full-thickness myotomy (P = .002), and procedure time (P = .001). After we adjusted for these risk factors, cumulative sum analysis showed that the primary composite outcome decreased gradually after 100 cases. The procedure time was high during the first few cases and decreased after endoscopists performed 70 cases. The secondary composite outcome of technical failure, adverse events, and clinical failure for the 192 cases performed by only the original surgeon gradually decreased after 90-100 cases.

In a retrospective analysis of POEM procedures, we found that 100 cases were required to decrease the risk of technical failure, adverse events, and clinical failure (the learning curve). Seventy cases can be considered the threshold for decreasing procedure time.