Serial Radiographic Imaging for Real-Time Evaluation of Blood Flow During Low Anterior Resection: Initial Study in a Porcine Model

To determine whether real-time intraoperative serial radiographic imaging of the marginal artery and vasa recta is feasible in patients undergoing low anterior resection, we attempted such imaging in a porcine model using a specialized fluoroscopic digital X-ray system and thin flat panel detector. Of the possible complications after low anterior resection, anastomotic dehiscence is one of the most serious, with poor blood supply in the anastomotic region being a chief contributor. General anesthesia was induced in a male domestic pig, and a midline incision was made from the xiphoid process to just above the bladder. The rectum was transected at the peritoneal reflection and then mobilized by dissection of the right leaf of the sigmoid mesocolon from the inferior mesenteric artery to the superior rectal artery. The rectal stump was pulled out and placed directly on the detector. Noniodine contrast agent was injected, and blood flow to and from the area surrounding the rectum was evaluated. Serial radiographs depicting the superior rectal artery, colonic, rectal, surrounding mesenteric tissue, and the vasa recta were obtained. The region where the marginal artery ran along the distal portion of the rectal stump was poorly poor imaged in all 3 imaging phases. Diameters of arteries were easily determined. The success we had in radiographically observing blood flow in tissues that would be involved in low anastomosis convinced us that such intraoperative evaluation is clinically feasible.