436 Peroral Endoscopic Myotomy Is a Safe and Effective Treatment Modality for Achalasia After Prior Failed Botulinum Toxin Treatment

Abstract

INTRODUCTION: Peroral endoscopic myotomy (POEM) is shown to be effective in patients with recurrent symptoms after prior treatments such as Heller myotomy (HM) or pneumatic dilatation (PD) or Botulinum toxin (Botox) injection into lower esophageal sphincter (LES). However there is lack of a systemic study analyzing POEM in patients with prior Botox treatment alone and not confounded by other treatments. Previous Botox treatment leads to submucosal fibrosis making sub-mucosal dissection and separation of tissue planes more challenging during POEM. Hence, our study aims were to determine the safety and efficacy of POEM in achalasia patients who previously received exclusively Botox treatments. METHODS: Medical records of all achalasia patients who underwent POEM at our institution between April 2014 and May 2019 were reviewed. Patients who underwent timed barium esophagram (TBE) and high-resolution manometry (HREM) prior to POEM along with two-month post-POEM esophageal pH study, TBE and HREM were included. Patients were categorized into two groups as: no prior Botox (treatment naïve) and prior Botox group. Patients with prior HM or PD were excluded from both groups. Baseline patient characteristics, procedural details, TBE, HREM, pH study findings and Eckardt’s scores were compared between the two groups. Post-POEM Eckhardt’s score of ≤3 was considered as successful palliation of symptoms. RESULTS: From a total of 200 patients undergoing POEM, 103 patients met the study criteria (prior Botox = 35; treatment naïve = 68). Patients with no prior Botox injections were younger, had high LES integrated relaxation pressure (LES-IRP) on HREM, wider esophagus on TBE at 1 and 5 minutes. In terms of operative details and outcomes, the total myotomy length, operative time, complications, length of stay and 30-day readmission rates were similar for both groups (Table 1). POEM was successful in 96.9% and 93.8% patients in no Botox and prior Botox groups respectively. At two months post-POEM, similar improvements were noted in Eckhardt scores (Figure 1a), LES-IRP and height of barium columns at 1 and 5 minutes, however patients without prior Botox had greater improvement in TBE width at 1 and 5 minutes (Figure 1b,c). The rates of symptomatic GERD and abnormal esophageal pH study were also not significantly different between the two groups (Table 2). CONCLUSION: In achalasia patients with prior Botox injections, POEM is feasible and safe. Prior Botox treatment does not influence the efficacy of POEM.