Gastric Peroral Endoscopic Myotomy: A Specific Learning Curve

Gastric peroral endoscopic pyloromyotomy (G-POEM) is a novel option for patients with gastroparesis. It involves submucosal tunneling across the pylorus, followed by pyloromyotomy, and subsequent closure of the endoscopic tunnel. The aim of this study was to determine the learning curve for G-POEM.

Consecutive patients undergoing G-POEM by a single operator were included from a prospective registry over 2 years. Demographics, procedure info, postprocedure follow-up data, and adverse events were collected. Nonlinear regression and cumulative sum control chart analyses were conducted for the learning curve. Clinical outcomes were improvement in Gastroparesis Cardinal Symptom Index score and gastric emptying scintigraphy.

Thirty-six patients were included (16.7% M, mean age 46 y). The majority had idiopathic gastroparesis (n=16, 44%), with the remaining having diabetes (n=5, 17%), postsurgical (n=10, 28%), or other (n=4, 11%). Technical success was achieved in 35 of 36 (97%). There was a significant reduction in the total Gastroparesis Cardinal Symptom Index score (2.09 units, P<0.00001) and a significant reduction in postoperative gastric emptying scintigraphy (82.44 mins, P<0.00001). Mean follow-up was 15 months (SD, 1.05). Median procedure time was 60.5 minutes (range, 35 to 136). Cumulative sum control chart shows 60-minute procedure was achieved at the 18th procedure. Procedure durations further reduced with consequent procedures with the last 3 being 45 minutes, thus demonstrating continued improvement with ongoing experience (nonlinear regression P<0.0001).

Endoscopists experienced in G-POEM are expected to achieve a reduction in procedure time over successive cases, with efficiency reached at 60.5 minutes and a learning rate of 18 cases with continuing improvement.