Peroral endoscopic myotomy (POEM) for complex achalasia and the POEM difficulty score

<jats:sec><jats:title>Background</jats:title><jats:p>Peroral endoscopic myotomy (<jats:styled-content style="fixed-case">POEM</jats:styled-content>) for achalasia is technically challenging to carry out in patients with type <jats:styled-content style="fixed-case">III</jats:styled-content>, multiple prior treatments, prior myotomy, and sigmoid type. Herein, we present a series of consecutive patients with complex achalasia and introduce the <jats:styled-content style="fixed-case">POEM</jats:styled-content> difficulty score (<jats:styled-content style="fixed-case">PDS</jats:styled-content>).</jats:p></jats:sec><jats:sec><jats:title>Aim</jats:title><jats:p>To demonstrate the application and discuss the utility of <jats:styled-content style="fixed-case">PDS</jats:styled-content> and present the feasibility, safety, and efficacy of <jats:styled-content style="fixed-case">POEM</jats:styled-content> in complex achalasia patients.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Forty consecutive <jats:styled-content style="fixed-case">POEM</jats:styled-content> were carried out with 28 meeting the criteria for complex achalasia. Primary outcome was clinical success (Eckardt score ≤3) at a minimum of 3 months follow‐up. Secondary outcomes included adverse events, procedural velocity and <jats:styled-content style="fixed-case">PDS</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Twenty‐eight complex and 12 non‐complex <jats:styled-content style="fixed-case">POEM</jats:styled-content> procedures were carried out with 100% and 92% clinical success, respectively, without any major adverse events with a median follow up of 15 months (complex) and 8 months (non‐complex). Mean velocities for non‐complex, type <jats:styled-content style="fixed-case">III</jats:styled-content>, prior myotomy, ≥4 procedures and sigmoid type were as follows: 4.4 ± 1.6, 4.8 ± 1.5, 5.9 ± 2.2, 6.9 ± 2.2 and 8.2 ± 3.2 min/cm, respectively. Median <jats:styled-content style="fixed-case">PDS</jats:styled-content> for non‐complex, type <jats:styled-content style="fixed-case">III</jats:styled-content>, prior myotomy, ≥4 treatments and sigmoid type were 1 (0–3), 2 (0–4), 2.5 (1–6), 3 (2–6) and 3.5 (1–6), respectively. <jats:styled-content style="fixed-case">PDS</jats:styled-content> was shown to correlate well with procedural velocity with a correlation coefficient of 0.772 (Spearman's <jats:italic>P</jats:italic> < 0.001).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p><jats:styled-content style="fixed-case">PDS</jats:styled-content> identifies the factors that contribute to challenging <jats:styled-content style="fixed-case">POEM</jats:styled-content> procedures and correlates well with procedural velocity. The order of increasing difficulty of <jats:styled-content style="fixed-case">POEM</jats:styled-content> in complex achalasia appears to be type <jats:styled-content style="fixed-case">III</jats:styled-content>, prior myotomy, ≥4 treatments and sigmoid type.</jats:p></jats:sec>