Table 1.

American Association for the Surgery of Trauma grading of small bowel injury and duodenal trauma

Grade	Small bowel	Duodenum
I	Contusion or haematoma without devascularisation; partial-thickness laceration, no perforation	Single segment haematoma; partial-thickness laceration, no perforation
II	Laceration <50% of circumference	Multiple segment haematoma; laceration <50% of circumference
III	Laceration ≥50% of circumference without transection	Laceration 50–75% of circumference of D2, or 50–100% of D1, D3 or D4
IV	Complete transection of the small bowel	Laceration >75% of circumference of D2, or rupture of ampulla or distal common bile duct
V	Transection of the small bowel with segmental tissue loss; devascularised segment	Massive duodenopancreatic injury; devascularisation of duodenum