The efficacy of intraoperative methylene blue enemas to assess the integrity of a colonic anastomosis

BACKGROUND: Intraoperative testing of colonic anastomoses is routine in assuring anastamotic integrity. We sought to determine the efficacy of the methylene blue enema (MBE) as an intraoperative test for anastomotic leaks. METHODS: This study is a retrospective review of consecutive colonic operations performed from January 2001 to December 2004 in a community hospital setting by a general surgical group that uses the MBE exclusively. All operations featuring a colonic anastomosis and an intraoperative MBE were studied (n = 229). Intraoperative MBE via a rectal tube was used as the diagnostic test. Intraoperative leak (IOL) rate and clinically significant postoperative leak (POL) rate were the outcome measures. RESULTS: The IOL rate was 4.5% for proximal anastomoses, 8% for distal anastomoses, and 7% of total anastomoses. The POL rate was 3% of anastomosis. There were no other testing methods employed. There were no POLs in cases where an IOL led to concomitant intraoperative repair. POL rate for proximal anastomosis was 0.8% and for distal 3%, for stapled 1% and hand sewn 5%. CONCLUSION: MBE IOL rate is comparable to published IOL rates for other methods of intraoperative testing. The MBE can be applied to proximal and distal anastomosis. Patients who were found to have an IOL, and underwent immediate repair, did not develop a clinical POL.