Anorectal Endoscopic Hybrid Resection of an Uncommon Cause of Debilitating Diarrhoea: Polypoid Supra-Anal Mucosal Prolapse Syndrome.

Endoscopic resection of supra-anal lesions is challenging due to marked fibrosis and generous venous plexus [1]. Furthermore, abundance of sensory nerve fibres in the anal canal calls for an adequate local anaesthesia otherwise not warranted in endoscopy [2]. This is the case of a 54-year-old male patient with a 2-year history of debilitating diarrhoea including inability to work (sic!), passing up to 25 watery stools with urgency. Prior gastroenterology consultations elsewhere including previous ileocolonoscopy did not indicate the cause of diarrhoea. Currently, the patient was scheduled for endoscopic resection of an estimated 15-mm, biopsy-confirmed mucosal prolapse polyp in the supra-anal rectum involving the dentate line. The retroflexed endoscopic visualization revealed a reddened polypoid lesion with an eroded surface, consistent with mucosal prolapse syndrome (Fig. 1a). For resection, a cap-fitted, antegrade endoscopic approach was chosen to first isolate the lesion from the squamous epithelium of the anal canal, which indeed was cut into in its proximal aspects after injection of an indigocarmine saline mixture without adrenaline and a local anaesthetic (Fig. 1b). To this end, limited endoscopic submucosal dissection using a Dual Knife J (Olympus, Hamburg, Germany) was performed under deep sedation using propofol and midazolam to ensure wide-margin resection at the anal side with diarrhoea most likely attributable to chronic sphincter irritation (Fig. 1c; note marked fibrosis and prominent vessels). Only after progression to the more oral rectum did the submucosal space begin to open up adequately (Fig. 1d). To accelerate the procedure and with a view to the benign histology, we subsequently opted for a hybrid approach ensnaring the lesion (30-mm snare; Medwork, Höchstadt, Germany) after adequate trimming of the anal parts of the lesion (Fig. 1e). The final resection bed was without bleeding;