[Sphincter-saving resection for low rectal cancer].

R0 resection, preservation of the anal sphincter, and local control are considered to be the most important target criteria in rectal cancer surgery. Many efforts have been made in recent years to increase the rate of sphincter preservation by performing pull-through operations, ultra-low anterior resection (U-LAR), and intersphincteric resection (ISR). U-LAR is the standard surgery for patients with lower rectal cancer to preserve anal function. Reconstruction in U-LAR is mainly performed using stapled anastomosis. Although conventional coloanal anastomosis makes it possible to preserve the anal sphincter, the mechanical methods are difficult. In that case, almost all the internal sphincter is preserved. The final options for preserving the sphincter are ISR and external sphincter resection (ESR). Although the internal sphincter is sacrificed partially, subtotally, or totally in ISR, and the external sphincter is resected partially or extensively in ESR, complete or incomplete anal function is maintained. However, the literature is not clear regarding long-term oncologic outcome and anal function after these procedures. The application of these surgical techniques can reduce the rate of abdominoperineal resection in very low rectal cancer. The indications for these procedures must be carefully determined based on tumor site and stage as well as the patient's own preference.