Treatment of achalasia with peroral endoscopic myotomy in situs inversus totalis.

Peroral endoscopic myotomy (POEM) has become established as a safe, effective, and versatile minimally invasive endoscopic treatment for achalasia and other esophageal motility disorders. Situs inversus totalis is a rare congenital disorder characterized by a completely reversed position (mirror-image) of the thoracic and abdominal visceral organs. This case report demonstrated a successful treatment of achalasia in a situs inversus totalis by POEM. Similar to the POEM procedure in a normal patient, it is important to maintain the orientation throughout the submucosal tunneling while keeping in mind the reversed orientation and anatomical landmarks. The submucosal tunnel and myotomy were created by an anterior approach which is in this case located at the reversed axis, at 10 o'clock position. There were no major technical modifications needed to be carried out by the operator. No adverse events were noted. Improvement in the Eckardt Symptom Score as well as the barium esophagogram and high-resolution manometry findings on 2-month follow-up exhibited that although POEM was performed in a reversed orientation, similar effects and outcomes were achieved, indicating a successful procedure in this case. In summary, by keeping in mind the reversed positioning and anatomical landmarks in situs inversus totalis, POEM shows to be a safe, effective, and versatile intervention in treating achalasia in situs inversus totalis without the need for major modifications in the procedural technique.