Simple mathematical equation to predict distance to gastroesophageal junction through the submucosal tunnel during peroral endoscopic myotomy.

Background and aim Accurate estimation of the distance to the gastroesophageal junction (GEJ) through a tunnel during per oral endoscopic myotomy (POEM) is technically challenging. The methods currently employed are often insufficient, and resultant errors may lead to incomplete myotomy and/or prolonged procedure times. Our hypothesis states that the additional distance while traversing the tunnel is directly proportional to the widest esophageal diameter; and is calculated by the formula X = Y + CZ (X = distance to the GEJ through the tunnel, Y = distance to the GEJ through the lumen, Z = widest esophageal diameter, C = arithmetic constant). This study evaluates the validity and accuracy of this hypothesis. Patients and methods This was a prospective single-center study with 80 patients, 12 in the pilot group and 68 in the study group. In the pilot group, Y was recorded during esophagogastroduodenoscopy (EGD) before POEM, Z on barium swallow/contrast enhanced computed tomography (CECT), and X was measured during POEM. Using the formula, mean C (SD) was calculated. In the study group, 'C' was substituted in the equation to predict the GEJ distance through the tunnel (Xp) before POEM. The operator was blinded to Xp and recorded the true Xt during POEM. The correlation between Xp and Xt was calculated. Results In the pilot group, the mean distances (cm, SD) for X, Y, and Z were 42.58 (3.33), 39.83 (3.08), and 4.39 (1.16), respectively. The calculated mean C was 0.63 (0.11). In the study group, the mean distances (cm, SD) for Y, Z, Xp, and Xt were 40.45 (2.58), 4.99 (1.43), 43.57 (2.68), and 43.54 (2.78), respectively. The Xp and Xt values demonstrated a high correlation (r = 0.97, P  = 0.000). Conclusions Formula X = Y + CZ reliably predicts the GEJ distance through a tunnel during POEM. It is user friendly and requires no additional resources.

Per rectal endoscopic myotomy for the treatment of adult Hirschsprung's disease: First human case (with video).

Hirschsprung's disease (HD) is a congenital disorder characterized by the absence of intrinsic ganglion cells in submucosal and myenteric plexuses of the hindgut; and presents with constipation, intestinal obstruction and/or megacolon. HD commonly involves the rectosigmoid region (short segment HD), although shorter and longer variants of the disease are described. Standard treatment involves pull-through surgery for short segment HD or posterior anorectal myotomy in selected ultrashort segment candidates. Third space endoscopy has evolved during the past few years. Per oral endoscopic myotomy and per oral pyloromyotomy are described for treatment of achalasia cardia and refractory gastroparesis, respectively. Using the same philosophy of muscle/sphincter disruption for spastic bowel segments, per rectal endoscopic myotomy could be considered as a treatment option for short segment HD. A 24-year-old male patient presented with refractory constipation since childhood, and habituated to high-dose laxative combinations. Diagnosis was confirmed as adult short segment HD by barium enema, colonoscopic deep suction mucosal biopsies and anorectal manometry. Histopathology confirmed aganglionosis in the distal 15 cm. By implementing principles of third space endoscopy, per rectal endoscopic myotomy 20 cm in length was successfully carried out. At 24-week follow up, the patient reported significant relief of constipation and associated symptoms. Sigmoidoscopy, anorectal manometry and barium enema confirm improved rectal distensibility and reduced rectal pressures. The present case report describes the first human experience of per rectal endoscopic myotomy for successful treatment of adult short segment HD.