Association between Irrigation Fluids, Washout Volumes and Risk of Local Recurrence of Anterior Resection for Rectal Cancer: A Meta-Analysis of 427 Cases and 492 Controls

BACKGROUND Rectal washout can prevent local recurrence after anterior resection of rectal cancer. Few studies have focused particularly on the association between irrigation fluids volume or agents and the risk of local recurrence after anterior resection of rectal cancer. OBJECTIVE To estimate the association between irrigation fluids types, volumes of rectal washout and risk of local recurrence after anterior resection for cancer. DATA SOURCES Relevant studies were identified by a search of Medline, Embase, Wiley Online Library, China National Knowledge Infrastructure, Cochrane Oral Health Group Specialized Register, Wanfang databases and Google Website from their inception until October 18,2013. STUDY SELECTION Studies reporting the association between rectal washout types and volumes and risk of local recurrence after anterior resection for cancer were included. INTERVENTIONS Eligible studies used rectal washout. Control groups were defined as no washout. STUDY APPRAISAL AND SYNTHESIS METHODS Random-effects model were used to obtain summary estimates of RR and 95% CI, with Stata version 11 and RevMan 5.2.5 softwares used. The quality of report was appraised in reference to the MINORS item. RESULTS Of the 919 rectal cancer patients in 8 included studies, a total of 61(6.64%) cases of local recurrence were reported, with a pooled RR 0.51 (95%CI = 0.28-0.92, P = 0.03). The RRs 0.37 and 0.39 in normal saline and washout volume (≥ 1500 ml normal saline) subgroup, respectively, indicated that rectal washout with normal saline, or ≥ 1500 ml in volume could significantly reduce local recurrence (LR) rate (95% CI = 0.17-0.79, P = 0.01; 95% CI = 0.18-0.87, P = 0.02) after anterior resection for cancer. LIMITATION The included studies were non-randomized observational studies, with diversity of study designs. CONCLUSION Rectal washout with normal saline alone can reduce the risk of local recurrence in patients with resectable rectal cancer, and 1.5 liters rectal washout in volume is recommended.