Injuries of the abdomen: types
CLASSIFICATION AND MECHANISMS
Abdominal trauma is classified as blunt, penetrating or blast injury; it may be isolated or part of polytrauma. Blunt mechanisms include road traffic collisions, falls, crush injury and direct blows. Penetrating mechanisms include stab and gunshot wounds. Injuries may involve solid organs (liver, spleen, kidneys), hollow viscera (stomach, small bowel, colon), mesentery, pancreas, diaphragm, major vessels or retroperitoneum. External wound size does not predict internal injury.
INITIAL ASSESSMENT
Follow ATLS: airway with cervical-spine protection, breathing, circulation/haemorrhage control, disability and exposure. Identify shock and treat immediately. Establish large-bore IV access, send FBC, blood group/crossmatch, coagulation, blood gas/lactate and metabolic panel. Activate major haemorrhage protocol when indicated. Examine for distension, tenderness, guarding, bruising, seat-belt sign, penetrating wounds, evisceration and pelvic instability. Repeated examinations are important because signs can evolve.
INVESTIGATIONS
eFAST rapidly detects free intraperitoneal fluid, pericardial fluid and pleural injury but a negative study does not exclude abdominal injury. Contrast-enhanced CT abdomen/pelvis is the investigation of choice in haemodynamically stable patients and grades solid-organ injury, active bleeding and associated injuries. Diagnostic peritoneal lavage is now rarely used but may have a role where imaging is unavailable or equivocal. Do not send an unstable patient with suspected ongoing intra-abdominal haemorrhage to CT.
SOLID-ORGAN AND HOLLOW-VISCUS INJURY
Liver and spleen injuries may cause major haemorrhage; stable patients are often managed non-operatively with monitoring and angioembolisation when appropriate. Renal injury is assessed with contrast CT including delayed phase when indicated; many are managed conservatively. Hollow-viscus and mesenteric injuries may present subtly and can cause delayed peritonitis; CT signs include free air, bowel-wall thickening, mesenteric stranding and unexplained free fluid. Pancreatic and duodenal injuries are often retroperitoneal and may be missed early. Diaphragmatic injury, especially left-sided penetrating trauma, can cause herniation.
MANAGEMENT PRINCIPLES
Immediate laparotomy is indicated for haemodynamic instability with suspected intra-abdominal bleeding, peritonitis, evisceration in appropriate circumstances, uncontrolled haemorrhage or clear hollow-viscus perforation. Damage-control surgery is used in profound shock, hypothermia, acidosis and coagulopathy: rapid haemorrhage/contamination control, temporary closure, ICU resuscitation and planned relook. Stable patients may undergo non-operative management with serial observations, haemoglobin and repeat imaging as indicated. Antibiotics are given for hollow-viscus injury/contamination and perioperatively according to protocol.
COMPLICATIONS
Complications include haemorrhagic shock, missed bowel injury, peritonitis, abscess, bile leak, pancreatic fistula, abdominal compartment syndrome, wound infection, thromboembolism and late stricture. A high index of suspicion and repeated assessment are essential.