Learning curve of a modified technique of peroral endoscopic myotomy (POEM) – analysis of safety and efficacy in 9 consecutive patients with follow-up

Introduction:

Peroral endoscopic myotomy (POEM) is an endoscopic treatment for esophageal motility disorders developed by Inoue in 2010. Full-thickness dorsal myotomy with hybrid-knife is a modification of the original POEM technique that shortens procedure time with similar efficacy and complication rates.

Methods:

After three months of structured learning (observation, animal training, supervised hands-on) at Zhongshan Hospital (Fudan University, Shanghai, China), the modified POEM technique was implemented at our department in 2017. This is an analysis of the learning curve, safety, efficacy and short-term follow up.

Results:

Within a 16-months-period 9 consecutive patients (male, n = 3; median age 57 years, range 24 – 65 years) with esophageal motility disorder (achalasia, n = 8; jackhammer esophagus, n = 1) underwent the modified POEM technique. 4/9 patients had already undergone previous pneumatic dilatations. All POEM procedures were performed under general anesthesia by one single endoscopist (WD). Length of myotomy was adapted to subtype of disease and was 11 cm in median (range 10 – 13 cm in achalasia patients, 21 cm in jackhammer esophagus). For achalasia, mean procedure time was 107 ± 58 min. for the first 4 patients and 65 ± 8 min. for the last 4 patients (p = 0.044, Levene's test for equality of variances). No serious adverse event occurred, neither during the procedure nor during post-interventional hospital stay or follow-up. Two patients developed mild subcutaneous emphysema which resolved spontaneously. Efficacy of the intervention was assessed with the Eckhardt symptom score for achalasia: 7.4 ± 1.5 vs. 1.1 ± 1.0 before and after treatment, respectively (p < 0.01, paired samples t-test). During follow-up (5.9 months in median, range 0.5 – 16.6 months) 1/9 patients developed heartburn (GERD Grade B at gastroscopy), all others remained free of reflux symptoms.

Conclusion:

In this study, the modified POEM technique showed a fast learning curve and was safe and highly effective on short term follow-up.