Peroral endoscopic myotomy for the treatment of achalasia after failed pneumatic dilation

Background and aims POEM is a rescue endoscopic therapy for patients who had previously failed surgical or endoscopic treatment. However, data regarding its effectiveness after failed pneumatic dilation (PD) and its long-term effects are limited. We aimed to retrospectively investigate the long-term outcomes in patients who had undergone POEM after failed PD. Methods Data from 66 achalasia patients with a 2-year follow-up period were analyzed. Intraprocedural events were compared between the first POEM group (patients without prior-endoscopic intervention) and prior PD group (patients who had pre-POEM PD). Symptom evaluation, HRM and 24 h-pH DeMeester scores between the two groups were performed at 2 years after the POEM procedure. Muscularis externa samples were obtained from the lower esophagus using POEM to assess the muscle fibrosis with Azan-Mallory staining. Results POEM was successfully performed for all achalasia patients. During the 2-year follow-up period, the success rate of POEM was 96.15% (25/26) for patients with prior PD and 95% (38/40) with primary POEM. For patients with type II achalasia and who underwent prior PD, the post-procedure DeMeester score was higher compared to patients who underwent POEM only ( P < 0.05). A larger number of patients who underwent primary POEM (27.50%, 11/40) complained of mild heartburn compared to patients who underwent POEM after PD (7.69%, 2/26) ( P < 0.05). With regards to fibrosis, the majority of patients who underwent POEM only were classified as F-1 (45.00%, 18/40), while the majority of patients who underwent prior PD were classified as F-2 (42.3%, 11/26). The degree of fibrosis was significantly different between the two groups ( P < 0.05). Both surgical time and prior PD were correlated with the degree of fibrosis ( P < 0.05). Conclusions Despite the technical challenges, pre-POEM endoscopic treatment does not impact the safety and efficacy of POEM in achalasia patients. Longer follow-up studies using larger cohorts are needed to determine long-term outcomes and complications of POEM.