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.