What Is the Place of Intersphincteric Resection When Operating on Low Rectal Cancer?

Figure 1

Schematic representation of the transaction lines for intersphincteric resection (ISR). The distal resection line of the internal anal sphincter (IAS) was at the dentate line (DL) (1) in partial ISR, between the DL and the intersphincteric groove (ISG) (2) in subtotal ISR, and at the ISG (3) in total ISR. AV: anal verge; DES: deep part of external sphincter; SES: superficial part of external sphincter; SubES: subcutaneous part of external sphincter; LAM: levator ani muscle.