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

A leak from a colorectal anastomosis is a post-operative complication surgeons fear the most, following colonic resection. Over the years, there have been multiple suggestions for intraoperative tests for the integrity of the colorectal anastomosis. Two of the most common tests that are performed routinely are: Air tight leak test - filling the pelvis with saline and insufflating air trans anal - looking for air bubbles in the saline filled pelvis. Injecting diluted dye (methylene blue) trans anal, and looking for blue dye stains on gauze pads covering the outer side of anastomosis. The aim of the study is to compare the two methods, and to assess if there is a superior method. A secondary aim is to establish standards to perform the test, mainly to assess the appropriate pressure to apply on the anastomosis. In this prospective study patients scheduled to undergo colonic resection of their distal part of the colon/ rectum with colorectal anastomosis, will have both testing methods performed sequentially and will be followed post-operative to assess the yield and sensitivity of the testing methods.

Intraoperative testing of colorectal anastomoses Insert a Foley catheter through the anus into the rectum. Insufflate the Foley balloon with 5 cc of air. fill the pelvic space with 500 CC of warm saline Insufflate air into the rectum up to a pressure of 35 mmH2o as measured by external manometer Remove the saline from the pelvic space. Inject methylene blue in to the rectum up to a pressure of 35 mmH2o measured by external manometer 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

Insert a Foley catheter through the anus into the rectum. Insufflate the Foley balloon with 5 cc of air. Air tight leak test with saline and insufflating air: fill the pelvic space with 500 CC of warm saline Insufflate air into the rectum up to a pressure of 35 mmH2o as measured by external manometer Remove the saline from the pelvic space. Inject diluted dye (methylene blue) in to the rectum up to a pressure of 35 mmH2o measured by external manometer 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

Inclusion Criteria: Patients over the age of 18 undergoing elective colonic resection of their distal part of the colon/ rectum with colorectal anastomosis in a laparoscopic or open approach for a benign or malignant colonic disease. Exclusion Criteria: Emergent colonic resections, Colonic resections with no colorectal anastamosis

Rudnicki Y, White I, Tiomkin V, Lahav L, Raguan B, Avital S. Intraoperative evaluation of colorectal anastomotic integrity: a comparison of air leak and dye leak tests. Tech Coloproctol. 2021 Jul;25(7):841-847. doi: 10.1007/s10151-021-02453-4. Epub 2021 Apr 27.