Long-term outcome of per anum intersphincteric rectal dissection with direct coloanal anastomosis for lower rectal cancer

Objective: The authors have performed per anum intersphincteric rectal dissection. With direct coloanal anastomosis for cases of lower rectal cancer in which the distal surgical margin is difficult to secure by the double stapling technique. The aim of this study was to evaluate the long-term outcome and to clarify the surgical indications for this operation. Patients and methods: Between 1993 and 2002, 31 patients underwent per anum intersphincteric rectal dissection with direct coloanal anastomosis. Of these, two patients (one stage 0 and one stage IV) were excluded from the analysis of oncological outcome. The remaining 29 patients formed the basis of this study. The median follow-up was 57 months (range 6-106 months). Results: Local recurrence and distant metastasis developed in 9 and 3 patients, respectively. Local recurrence rate for pT1 was significantly lower than that for pT2/T3 disease. The local recurrence rate cases with tumours less than 3 cm was significantly lower than that for tumours sized 3 cm or more. The distant metastasis rate for cases with lymph node metastasis was significantly higher than that for cases without lymph node metastasis. There was an association between distant metastasis and TNM or pT stage. The overall survival rates for stage I, II and III were 85%, 80% and 89%, respectively. No significant defference was seen in total Cleveland Clinic incontinence score between per anum intersphincteric rectal dissection with direct coloanal anastomosis and the double stapling technique. Conclusion: The surgical indications of this operation should be limited to patients with T1 rectal cancer or tumours less than 3 cm.