[A Cure Case of Rectal Arteriovenous Malformation with a Large Volume of Melena Caused by Surgery for Rectal Cancer].

This study presents the case of a 52-year-old male suffering from extensive melena. A detailed examination using lower gastrointestinal endoscopy revealed a polyp at the lower rectum; subsequently, endoscopic mucosal resection(EMR)was performed. No other lesion for the melena was observed. Histopathologic findings of the EMR confirmed adenocarcinoma in adenoma, indicating the need for additional surgery. Preoperative contrast-enhanced CT revealed an arteriovenous malformation( AVM)of about 5 cm in the rectal wall at the anal side of the lower rectal cancer. Extensive melena was inferred to be caused by AVM; hence, we performed laparoscopic low anterior resection combined with accessible excision of the AVM and blocked the superior rectal artery, acting as an inflow vessel. Postoperative contrast-enhanced CT confirmed the disappearance of AVM. Thus, we experienced a case in which the block of the inflow vessel, according to the treatment theory of embolism therapy without complete resection of the AVM, enabled the treatment of AVM. Therefore, this case could become a reference for the treatment of lower rectal AVM cases in the future.