Efficacy evaluation of anal intersphincteric resection with direct coloanal anastomosis for T1-2 ultra-low rectal cancer

Abstract

To evaluate the oncological and functional outcomes of intersphincteric resection (ISR) in T(1-2) ultra-low rectal cancer. From March 2000 to March 2007, ISR with total mesorectal excision (TME) was performed in 40 patients with very low rectal cancer,among whom total ISR in 5 patients, partial ISR in 23 patients, and partial ISR with partial dentate line preservation (modified partial ISR) in 12 patients. The preoperative tumor staging was T(1-2)N(0-1)M(0). Morbidity was identified in 3 patients including anastomotic leakage in 1 patient and wound infection in 2 patients, and there was no postoperative mortality. The 5-year overall survival rate was 97%, and 5-year disease-free survival rate was 86%. Both patients with modified partial ISR (P=0.004) and patients with partial ISR (P=0.008) had significantly better continence than those with total ISR, and patients with a diverting stoma had significantly better continence (P=0.043) than those without a stoma at 12 months after surgery. ISR is a safe procedure for sphincter-saving rectal surgery in selected patients with very low rectal tumors. A temporary diverting stoma may be beneficial to the improvement of anal function. Modified partial ISR under the precondition of radical resection shows better anal function and lower rate of incontinence.