Background: The presence of intraluminal tumour cells in colorectal cancer is known, as is their ability to implant in colorectal anastomoses, causing perianastomotic tumour growth. There is no consensus as to the volume and agent to use for rectal washout. The purpose of this study was to assess the efficacy of our current routine for rectal washout in eliminating intraluminal tumour cells.
Methods: Sixty consecutive patients undergoing low anterior resection or low Hartmann's procedure for rectal cancer at our unit were included. After the pelvic dissection was completed, the bowel was cross-clamped distal to the tumour and the prewashout sample (no. 1), was obtained by instilling 50 ml of saline and collecting the return fluid. A rectal washout followed using 500 ml of sterile water, 2 × 500 ml of 70 % ethanol and 500 ml of sterile water (sample no. 2-4) and the postwashout sample (no. 5) was obtained by using 50 ml of saline. The samples were examined and categorized as non-malignant or malignant at the Department of Pathology. The usual pathology report information was also assessed.
Results: In 33 of the 60 patients, cancer cells were identified in the prewashout sample. The rectal washout eliminated intraluminal cancer cells in 30 of the 33 patients. All of the remaining 3 had a higher blood loss (p = 0.026) and a tendency towards more polypoidal tumours (p = 0.053).
Conclusions: A rectal washout volume larger than 2,000 ml might be necessary to eliminate all intraluminal tumour cells in total mesorectal excision for rectal cancer.