[Indications and prognostic analysis of sphincter preservation operation for rectal cancer]

To explore the indications of sphincter preservation operation (SPO) for rectal cancer, and factors influencing selective indications of SPO.

From April 1994 to April 2004, clinical data of 708 cases with rectal cancer were analyzed retrospectively. The patients received either SPO (SPO group, n=481) or abdominoperineal resection (APR group, n=227). Clinical pathologic parameters and survival rate were compared between the two groups.

There were 66 patients with tumor located in sigmoid-rectum borderline, 138 in upper rectum, 195 in middle rectum, 309 in lower rectum. Dixon operation was performed in 449 patients, Bacon operation in 12, and "J" Poch anastomosis in 20 and Hartman operation in 13. There was no differences in sex, ages, liver metastasis, size, depth of invasion and Dukes stages between APR and SPO groups, but there was significant difference in lower bowel obstruction, tumor location, differentiation degree, infiltrated circumference of intestine, lymph node metastasis and radical approaches between the two groups. Radical excision was performed in 660 rectal cancer cases with radical excision rate of 91.5% . SPO was performed in 481 cases with preservation rate of 66.7%, including 135 lower rectal cancer with preservation rate of 43.7%. The operative mortality was 0.4% (3/708), regional recurrence rate was 5.51% (39/708) after operation. The median survival time was (65.0+/- 6.9) months in SPO group and (42.2+/- 5.6) months in APR group (P< 0.01), the 5-year survival rate was 59.3% and 42.3% in SPO and APR group (P< 0.001).

SPO should be considered as primary choice for rectal cancer patients, but it must be ensured that complete radical resection be performed. Indications for SPO in lower rectal cancer depend on tumor location,differentiation degree,and infiltrated circumference of intestine,lymph node metastasis.