Outcomes of anterior versus posterior peroral endoscopic myotomy for achalasia: a single-center retrospective analysis

Aims Peroral endoscopic myotomy (POEM) has gained a fundamental role in the treatment of achalasia. However, there is currently no consensus or universally accepted guidelines regarding the optimal myotomy orientation – anterior or posterior – during the POEM procedure. While both approaches are utilized by endoscopists, differences in outcomes, complication rates, and procedural details between these techniques remain a topic of ongoing investigation. This study aims to compare the anterior and posterior POEM approaches to evaluate effectiveness, safety profiles, and patient-centered outcomes.

Methods We performed a retrospective analysis of 654 POEMs performed at our third-level centre on patients diagnosed with achalasia by high-resolution manometry, from September 2013 to March 2023. All patients underwent endoscopic myotomy and oesophagogastroduodenoscopy the following day. Means of two groups were compared by using t-test or Mann Whitney U Test. Categorical variables were compared by using two-tailed Fisher’s exact test and chi-square test.

Results 558 patients underwent endoscopic myotomy with an anterior approach and 96 patients with a posterior approach, with no statistically significant difference in terms of preoperatory characteristic as age, gender, duration of symptoms, type of achalasia or integrate relaxation pressure (IRP) value between the two groups. Of all the procedures performed, only 6 failed, all belonging to the anterior approach group. The mean of procedure time for anterior group was 43.8 min±20.2 vs 34.5 min±15.8 of the posterior group (p-value<0,0001), while the mean of myotomy length was 7.7 cm±2.9 for the anterior group and 9.2 cm±2.3 for the posterior group (p-value<0,0001). Moreover, a further statistically significant difference was found in the number of clips used for incision closure, which was found to be 5.4±1.6 for anterior approach and 4.3±1.5 for posterior approach (p-value<0,0001). At the follow-up oesophagogastroduodenoscopy performed the day after the procedure, mucosal ulcers>1 cm were found in 9.4% of patients, only in the anterior approach group (p-value 0,0018). No differences between the two groups were found with regard to hospitalization duration, time to feeding or adverse events. Complications occurred in 2.34% of patients in the anterior group and in 3.13% of patients in the posterior group. Only 1 serious adverse event was recorded in the entire study population. The mean follow-up was 30.4 (± 19.7) and 29.25 (± 22.67) months for anterior and posterior myotomy, respectively. No significant differences have been found about clinical success and incidence of GERD among the groups.

Conclusions In a large cohort of achalasia patients from a high-volume endoscopy center, the retrospective analysis of two different technical approaches in performing POEM showed overlapping results in terms of technical success, perioperative outcomes, and safety. Statistically significant differences were found in the duration of the procedure, length of the myotomy, intraprocedural use of clips and mucosal ulcers found at endoscopic control.

Publication History

Article published online:
27 March 2025