Intersphincteric resection and coloanal anastomosis

Radical resection for low rectal cancer is the mainstay among the treatment modalities. Intersphincteric resection (ISR) is considered a relatively new but effective surgical treatment for low-lying rectal tumor. With the advance of treatment modality, patients who have undergone abdominoperineal resection in the past can be treated with ISR. Furthermore, preoperative chemoradiation induces tumor downstaging and facilitates anal sphincter-preserving surgery. To achieve good oncologic outcomes, appropriate patient selection based on magnetic resonance imaging (MRI) is also important because MRI provides accurate information on the extent of tumor invasion and the anal canal structures. On top of all, meticulous surgical technique based on anatomical dissection is essential. Future investigations should be directed in improving functional outcomes after ISR.