To the Editor.—Arteriovenous malformations (AVMs) are being identified more frequently as the cause of gastrointestinal tract bleeding. The preoperative localization of AVMs is dependent on selective visceral angiography or radionuclide studies. Even then, the site may be difficult to locate at operation. Recently, reports have described the localization of AVMs in the small and large intestine using intraoperative ultrasonography to detect the difference in the flow pattern of vessels supplying the AVM.1,2 This report describes the use of intraoperative Doppler ultrasonography to locate an AVM of the sigmoid colon.
Report of a Case.—The patient was a 23-year-old woman who had hematochezia that occurred during a ten-month period. Selective visceral angiography revealed the early filling of a vein that drained the sigmoid colon. At surgery, a 9-MHz Doppler probe was used to identify the blood flow in the arteries supplying the colon. The arteries on the mesenteric border