Intraoperative Testing of Colorectal Anastomosis - Air or Water (Methylene Blue)?

"1. Insert a Foley catheter through the anus into the rectum.~2. Insufflate the Foley balloon with 5 cc of air.~3. Air tight leak test with saline and insufflating air: fill the pelvic space with 500 CC of warm saline~4. Insufflate air into the rectum up to a pressure of 35 mmH2o as measured by external manometer~5. Remove the saline from the pelvic space.~6. Inject diluted dye (methylene blue) in to the rectum up to a pressure of 35 mmH2o measured by external manometer~7. Remove the methylene blue from rectum.~NB the above procedures are standard practice for assessing the quality of colorectal anastomoses during colorectal surgery.~The purpose of the study is to compare these standard methods of evaluation to determinant which method is superior"

After the resection we do the stapled colorectal anastomosis with a standard circular stapler as part of the regular procedure