POEM IN TYPE 3 ACHALASIA. IS A LONG MYOTOMY NECESSARY?

Background: Type 3 achalasia patients are believed to require longer myotomies to address the spastic esophagus in addition to the non-relaxing sphincter. This has been espoused on recent guidelines that advocate POEM in preference to Heller in these patients. However, recent data suggest that a long myotomy may not be necessary (for example, similar success of POEM and Heller in type 3 patients in the European randomized trial and absence of correlation between myotomy length and POEM success in type 3 patients in a recent meta-analysis). We have also gradually come to this realization and, over the past decade, have progressively shortened our POEM myotomy length in type 3 patients. Careful patient follow-up did not indicate any deterioration in outcomes. We present a detailed analysis of our accumulated data. Methods: From our prospectively maintained database of POEM procedural data and outcomes we extracted all POEMs on type 3 patients with minimum follow-up of 2 years. We identified 124 such POEMs out of 787 POEMs performed from 10/2009 to 11/2021. Since our POEM myotomy in type 3 patients was shortened gradually over this period, in order to analyze the effect on POEM outcomes, we compared consecutive chronological groups. We divided the patients into 4 equal consecutive groups (31 patients per group). Baseline characteristics and outcomes were compared between the 4 groups. Results: Figure 1 demonstrates our progressive shortening of the POEM myotomy across the 4 groups (19cm, 16cm, 12cm, 9cm, p<0.001), mainly due to shortening of the esophageal myotomy (figure 2). There were no differences in baseline characteristics or clinical success with all groups having a median Eckardt score (ES) of zero. A trend towards higher clinical efficacy in the most recent groups was seen (at a less stringent alpha of 0.1) when assessed as % of patients with success (84%, 97%, 90%, 100%, p=0.075) or as % of patients with ES≥2 (19%, 9.7%, 6.5%, 0%, p=0.06). This trend is most likely due to the expected progressively shorter follow-up across the 4 groups (median follow-up in months: 92, 74, 59, 36, p<0.001) rather than superior efficacy of shorter vs longer myotomy. No significant differences in GERD symptoms, erosive esophagitis, length of stay and adverse events. There was a decrease in POEM procedure time consistent with growing operator experience. However, this occurred early on, in group 1 (87 min) with groups 2, 3 and 4 having similar procedure times (56, 55, 53 min). Conclusion: We present intriguing data from our large cohort of POEMs in type 3 achalasia patients that suggest that standard length myotomies may be non-inferior to long myotomies. These data should be confirmed in randomized trials.