Magnetic resonance imaging in rectal cancer: A surgeon’s perspective

Table 2 Classification of low rectal cancers Shihab et al[41]

Level	Tumor height	Tumor depth	Operative plane
1	Tumor height between levator origin and puborectalis sling	Confined to muscle	LAR/intersphincteric APE
		Beyond muscle	LAR/intersphincteric APE
		Tumor < 1 mm MRF/levator	Extralevator APE
		Tumor extending beyond levator	Extralevator APE
2	Tumor at or below puborectalis sling	Submucosal/partial thickness muscle	LAR/intersphincteric APE
		Full thickness muscle	Extralevator APE
		In to intersphincteric plane	Extralevator APE
		In to external sphincter	Extralevator APE
		Beyond external sphincter into ischiorectal tissue	Pelvic exenteration

APE: Abdominoperineal excision; LAR: Low anterior; MRF: Mesorectal fascia.