Third-Space Endoscopy: Recent Updates

Third space or submucosal space is a potential space which on expansion allows the endoscopist to execute a multitude of therapeutic procedures for various gastrointestinal diseases like achalasia, subepithelial tumors, Zenker’s diverticulum, and refractory gastroparesis. Third space was first utilized for performing endoscopic myotomy in cases with achalasia cardia about a decade ago. Since then, the field of submucosal endoscopy has witnessed an exponential growth. The present review focuses on recent advances in the field of third-space endoscopy. With regard to per-oral endoscopic myotomy (POEM) in achalasia cardia, several recent studies have evaluated the long-term outcomes of POEM, compared endoscopic myotomy with pneumatic dilatation (PD) and surgical myotomy, and evaluated the outcomes of short- versus long-esophageal myotomy. In addition, the utility of multiple dose antibiotic prophylaxis to prevent infections after POEM has been questioned. Overall, the results from these studies indicate that POEM is a durable treatment modality, equally effective to Heller’s myotomy and superior to PD. With regard to gastric-POEM (G-POEM), recent studies suggest only modest efficacy in cases with refractory gastroparesis. Therefore, quality studies are required to identify predictors of response to optimize the outcomes of G-POEM in these cases. Another third-space endoscopy procedure that has gained popularity is endoscopic division of septum in cases with esophageal diverticula including Zenker’s POEM and epiphrenic diverticula POEM (Z-POEM and D-POEM, respectively). The technique of diverticulotomy using the principles of submucosal endoscopy appears safe and effective in short term. Data on term outcomes are awaited and comparative trials with flexible endoscopic myotomy required. Per-rectal endoscopic myotomy (PREM) is the most recent addition to third space endoscopy procedures for the management of short-segment Hirschsprung’s disease. Limited data suggest that PREM may be a promising alternative surgery in these cases. However, quality studies with long-term follow-up are required to validate the outcomes of PREM.

Peroral endoscopic myotomy in a pediatric patient with refractory achalasia: a case report and review of the literature

A 15-year-old male patient presented with dysphagia, regurgitation, weight loss and retrosternal pain. The diagnosis of achalasia was made 4 years before. The esophagogram revealed severe esophagus dilatation and the classic “bird-beak” termination. A Heller myotomy plus fundoplication and endoscopic balloon dilatation were conducted four months previously. Nevertheless, the symptoms persisted and the last high-resolution manometry study still showed achalasia type II. The patient underwent a peroral endoscopic esophageal myotomy (POEM). POEM is a feasible and safe procedure for experienced and properly- equipped health care delivery centers and could be used as a rescue treatment in refr e present the youngest patient with achalasia in our region who had a successful response to rescue POEM.

Short versus standard esophageal myotomy in achalasia patients: a systematic review and meta-analysis of comparative studies

Background and study aims Despite the clinical efficacy of peroral endoscopic myotomy (POEM), postoperative symptomatic gastroesophageal reflux disease (GERD) remains a major concern. While it is known that length of the gastric myotomy affects postoperative GERD, the clinical relevance of variation in esophageal myotomy length is not well known. We performed a systematic review and meta-analysis of studies comparing outcomes of short versus standard myotomy length in patients with achalasia. Patients and methods We searched multiple databases from inception through November 2020 to identify studies that reported on outcomes of achalasia patients who underwent short compared with standard esophageal myotomy. Meta-analysis was performed to determine pooled odds ratio (OR) of clinical success, GERD outcomes, and adverse events with the two techniques. Results 5 studies with 474 patients were included in the final analysis (short myotomy group 214, standard myotomy group 260). There was no difference in clinical success (OR 1.17, 95 % confidence interval [CI] 0.54–2.52; I2 0 %; P = 0.69), postoperative symptomatic GERD (OR 0.87, 95 %CI 0.44–1.74; I2 29 %; P = 0.70), and overall adverse events (OR 0.52, 95 %CI 0.19–1.38; I2 40 %; P = 0.19), between the two groups. Incidence of postoperative erosive esophagitis as determined by endoscopy was lower in the short myotomy group (OR 0.50, 95 %CI 0.24–1.03; I2 0 %; P = 0.06). Conclusion Our analysis showed that performing POEM with short esophageal myotomy in achalasia was as safe and effective as standard myotomy, with lower incidence of postoperative erosive esophagitis.