Exfoliated cancer cells during intersphincteric resection for very low rectal cancer

PURPOSE

To investigate the frequency of exfoliated cancer cells and the efficacy of rectal washout during intersphincteric resection (ISR) in patients not receiving chemoradiotherapy (CRT) for very low rectal cancer.

METHOD

The subjects of this prospective study were 16 consecutive patients who underwent ISR without CRT for very low rectal cancer. Brushing cytology of the posterior anorectal wall was performed twice in each step of the ISR procedure and the samples were sent for blind cytological examination to identify exfoliated cancer cells.

RESULTS

Exfoliated cancer cells were identified in 9 of 13 patients (69%) preoperatively. The number of cancer cells identified after abdominal total mesorectal dissection decreased significantly from 94% (15/16) to 25% (4/16) after transanal irrigation with 2000 mL saline (p < 0.001). No cancer cells were identified after swabbing the anal wall following transanal dissection with purse-string closure of the distal stump. No suture-line recurrence was found during a median follow-up duration of 6 years.

CONCLUSION

Exfoliated cancer cells, confirmed in 94% of patients after total mesorectal excision, could be eliminated by performing rectal irrigation after clamping the rectum proximal to the tumor and swabbing the anorectal wall during ISR.

The effect of intraoperative rectal washout on local recurrence after rectal cancer surgery: a meta-analysis

BACKGROUND

Implantation of exfoliated cancer cells has been suggested as a possible mechanism of local recurrence at the site of colorectal anastomosis. Intraoperative rectal washout has been suggested to eliminate free cancer cells; however, there is no conclusive evidence of a beneficial effect of intraoperative rectal washout on local recurrence after anterior resection of rectal cancer.

METHODS

Studies published through February 2012 evaluating the impact of intraoperative rectal washout for local recurrence or positive cytology from donuts wash were identified by an electronic literature search. A meta-analysis was performed using the DerSimonian-Laird random-effects models to compute risk ratio (RR) along with 95% confidence intervals (CI).

RESULTS

Nine studies met the inclusion criteria, yielding a total of 5,395 patients. Eight studies evaluated overall local recurrence, including anastomotic recurrence, and five of the eight studies evaluated anastomotic recurrence separately. Two studies evaluated positive cytology from donuts wash. Local recurrence rate was 5.79% in the washout group and 10.05% in the no washout group-a difference that was statistically significant (RR = 0.57; 95% CI = 0.46-0.71; P < 0.00001). Rectal washout significantly reduced the risk of anastomotic recurrence (RR = 0.3; 95% CI = 0.12-0.71; P = 0.007). No influence of rectal washout was observed on positive cytology from donuts wash.

CONCLUSIONS

From the results of this meta-analysis, it may be justified to recommend intraoperative rectal washout to prevent local recurrence in rectal cancer surgery.