Abdominal trauma

Introduction

• 15-20% of all trauma deaths
• Liver most commonly injured abdominal organ
• Spleen most frequent in sports injuries
• Patients who survive initial traumatic insult suffer mortality and morbidity as a result of sepsis

Blunt trauma

• MVA most common
• Injury is common at transition between mobile and fixed regions
• Ligament of Trietz and distal small bowel represent transition areas where mesenteric and small bowel injuries occur
• Fall from height typically leads to hollow organ rupture
• Retroperitoneal injury and haemorrhage occur as force transmitted along axial skeleton
• Struck pedestrians, motorcyclists and bicyclists are at high risk of intra-abdominal injuries

Penetrating trauma

• Assume any injury to the lower chest, pelvis, flank or back to have penetrated the abdominal cavity until proven otherwise

Clinical presentation

• Cullen’s and Grey-Turner’s sign represent delayed findings in intraperitoneal haemorrhage
• Ideally same provider serial examinations
• Up to 45% of blunt trauma patients with initial benign abdomen are later found to have significant intra-abdominal injury
  • Reliance on physical examination alone in high-energy mechanism leads to unacceptably high miss rate
  • Repeated examination is key and with this sensitivity remains high but non-specific

Clinical presentation

• Abdominal wall injury
  • Pain with flexion/rotation and focal tenderness to percussion
  • Rectus haematomas often present as palpable masses below the umbilicus
• Solid organ injuries
  • Signs and symptoms generally related to blood loss
  • Hypotension may not occur until 30% blood volume loss
  • Delayed rupture can occur in liver and spleen injuries
  • Splenic injuries may cause referred pain to the left shoulder or arm
  • Liver injuries may refer pain to the right shoulder or arm
  • Pregnancy and mononucleosis predispose patients to splenic injuries

Clinical presentation

• Hollow viscous and mesenteric injuries
  • Seen in around 5% of blunt trauma patients
  • Symptoms due to blood loss and peritoneal contamination
  • Gastric contents in peritoneum = Immediate irritation
  • Bacterial contamination of peritoneum may cause delayed peritonism
  • Delays in diagnosis and treatment are associated with increased mortality

Clinical presentation

• Retroperitoneal injuries
  • Pancreas
    • Seen in 4% of abdominal trauma patients with significant morbidity and mortality
    • Occurs occurs in rapid deceleration, unrestrained drivers who hit steering column or bicyclists against handlebar end
    • May be initially minimally symptomatic
  • Duodenum
    • Often asymptomatic on presentation. Subtle and easily missed. Repeat abdominal examination even in negative abdominal CT scans is crucial with high index of suspicion
    • As duodenal haematoma expands, gastric outlet obstruction develops
    • Rupture often occurs in high-velocity deceleration events where intraluminal pressure of pylorus and proximal small bowel rapidly increases
    • Ruptured contents may be confined to retroperitoneum without peritoneal findings. Fever and leukocytosis in delayed presentation herald abscess/sepsis
    • Maintain high degree of suspicion in any patient with ongoing abdominal pain despite normal CT

Clinical presentation

• Diaphragmatic injuries
  • Diaphragm spasm (winded) after direct blow to epigastrium (self-resolves)
  • Rupture due to penetrating or high-velocity deceleration with rise in abdominal pressure
  • 0.8-5% of thoracoabdominal trauma patients suffer rupture and almost exclusively left-sided
    • Now thought to be 50% each side roughly
  • Delayed diagnosis may lead to herniation/strangulation/incarceration of bowel in defect
  • Management
    • NG tube decompression
    • Careful ICC on same side if any pneumo or haemothorax at same intercostal level as usual

Diagnosis

• Abdominal injuries that need expanded evaluation
  • Abdominal pain, tenderness, distension or external signs of trauma
  • MOI with high likelihood of injury
  • Suspicious lower chest, back or pelvic injury
  • Inability to tolerate delayed diagnosis e.g. coagulopathy, elderly, liver cirrhosis, portal hypertension
  • Distracting injuries
  • ALOC

Ultrasonography

• FAST for detection of free intraperitoneal fluid in unstable blunt trauma patient for decision to go to theatre vs. CT
  • Average time is 4 minutes or less
  • Massive haemoperitoneum detected with single Morrison’s pouch view in 82-90% of hypotensive patients in 19 seconds
  • Cannot detect source of bleeding
  • Difficult if inexperienced, obese, subcut air, excessive bowel gas, ascites
  • Retroperitoneal bleeds missed
• Can also look at IVC volume (marker of intravascular volume and mortality)

CT

• PO contrast risks aspiration and is too time consuming
• IV contrast allows precise localisation and grading of injury
• Can quantify and differentiate the amount and type of fluid in the abdomen
• Can evaluate retroperitoneal injuries
• Multiphasic (arterial, portal and equilibrium) accurately identifies mesenteric haemorrhage and transmural bowel injuries
• Flat IVC suggests hypovolaemia
• Small amount of free fluid with no clear source can be managed either via exploratory laparotomy OR observation and repeat CT with oral contrast
• Outcomes and time to definitive care are not improved by repeat CT imaging at accepting trauma centre

CT phases

• Arterial (t = 30 seconds)
  • Bright contrast in arteries with potential for blush outside of vasculature at site of arterial bleeding
• Portal venous (t = 80 seconds)
  • Contrast is less dense (spread out longitudinally within venous vasculature) and any arterial injury blush is brighter and larger than on arterial phase
  • Shows solid organ injury best as whole organ is enhanced

Clues to bleeding site

• Sentinel clot
  • Higher density blood is seen around the site of actual injury within free fluid pockets of the abdomen
• Subcapsular haematoma vs. peri-organ haematoma
  • Subcapsular haematomas show mass effect on organ parenchyma
  • Peri-organ haematomas show normal organ contours
• Arterial bleeding is much brighter on both arterial and venous phases than venous bleeding
• May see river of contrast into a haematoma in arterial bleeding
• Pseudoaneurysm
  • Punctate contrast vascular abnormality without a river of contrast
  • Often actively bleed later and often warrants interventional embolisation to prevent deterioration
• AV fistula
  • River of contrast without a haematoma
  • May visibly track between an artery and vein
• Urinoma vs. haematoma
  • Urinomas will show contrast leak into it if a delayed phase is performed once contrast has been filtered through kidneys
• Right and left inframesocolic spaces
  • Blood forms triangles within the centre of the abdomen and is usually from a small bowel or mesenteric injury
  • Small bowel perforations may not show free gas as often fluid-filled
• Lesser sac
  • Usually duodenal or pancreatic injury
• Paracolic gutters
  • Intraperitoneal bleeding, often solid-organ in origin
  • Lie in front of and either side of the ascending and descending colon
  • Remember, behind the ascending and descending colon is retroperitoneal

Penetrating trauma diagnosis

• CT, US still used
• Mandatory exploration of patients with stab wounds yields unacceptably high rates of non-therapeutic laparotomy
• Physical examination alone misses important intra-abdominal injuries
• Locally explore anterior abdominal wall wounds to assess for violation of the peritoneum
• CT helps guide operative vs. conservative management if haemodynamically stable
• If unstable, straight to theatre (red blanket)

Treatment

• Laparotomy
  • Rarely misses an injury
  • Allows for complete evaluation of the abdomen and retroperitoneum
  • All patient with persistent hypotension, abdominal wall disruption or peritonitis require surgical exploration
  • Extraluminal, intra-abdominal or retroperitoneal air also warrants surgical exploration

Indications for laparotomy

Non-operative management

• CT grading of solid organ injury
  • Does not always correlate with laparotomy findings and does not always predict the success of conservative management
  • Operative grading may underestimate internal organ damage
  • CT is a single snap-shot in time rather than a dynamic assessment
• Conservative therapy is far riskier in elderly patients (capsules weaken and consequences of re-bleeding far higher)
• Patients without vascular injury can usually be managed conservatively
  • If vascular injury does exist, percutaneous transcatheter embolisation can arrest haemorrhage
• Interventional radiology is primarily utilised for non-operative management of solid-organ injury with haemorrhage/vascular injury following blunt trauma

REBOA

• Resuscitative endovascular balloon occlusion of the aorta
• For patients with suspected abdominal trauma in extremis
• Maintains or increases perfusion to heart and lungs in the setting of blunt or penetrating abdominal trauma while avoiding the morbidity of emergent thoracotomy for aortic clamping
• Femoral artery accessed, latex balloon placed inside sheath (based on zone target):
  • Zone I: Descending thoracic aorta between origin of left subclavian and celiac trunk
  • Zone II: Between celiac and lowest renal artery
  • Zone III: Between lowest renal artery and bifurcation of aorta
• Sixty minutes of aortic occlusion is tolerable and recoverable

• In one small observational study, was associated with fewer early deaths and improved overall survival compared with resuscitative thoracotomy
• AAST review comparing 85 REBOA with 202 resuscitative thoracotomy patients, survival to discharge was 10% with REBOA and 3% for thoracotomy
  • For those not requiring CPR, survival to discharge was 22% vs. 3%

• Physiology
  • May increase central perfusing pressure by up to 50mmHg, albeit temporarily to prevent cardiac arrest
  • Animal models have shown survival benefit in torso trauma
  • May limit bleeding (although potentially limited benefit in venous bleeding)

• Indications
  • Not clearly elucidated
  • Abdominal or pelvic haemorrhage with detectable pulse but SBP <80mmHg
  • Cardiac arrest if thoracic haemorrhage and tension ruled out
• Abdominal trauma with shock
  • Zone 1 REBOA
  • Left subclavian to celiac trunk
• Pelvic trauma with shock
  • Zone III REBOA
  • Infrarenal aorta

• Contraindications
  • If not candidates for resuscitative thoracotomy
  • If penetrating thoracic trauma
  • If thoracic haemorrhage
• Outcomes
  • One retrospective review of 259 REBOA patients showed no difference in any outcome
  • Unclear benefit

• Complications
  • Arterial injury at site
  • Thromboembolic complications
  • Ischaemic to internal organs and lower limbs
  • Reperfusion injury
  • Delay to definitive surgery potentially

Disposition

• Need appropriate follow-up and instructions to return if discharged
  • Fever, vomiting, increased pain, dizziness, weakness or fatigue
• May require observation or admission for conservative management
• Much riskier if no CT performed

Last Updated on May 14, 2024 by Andrew Crofton