Liver Trauma

Background Largest solid abdominal organ,fixed position Second most common injured, but most common cause of death after abdominal trauma Blunt MVA most common 80% adults, 97% children-conservative rx

Pathophysiology Friable parenchyma, thin capsule, fixed position in relation to spine. Right lobe gets hit more since its larger, and closer to ribs. 85% injuries involve segments 6,7,8 from compressioin against ribs, spine, abd wall. Shear forces at attachments to diaphragm Transmission thru right hemithorax.

Pathophysiology Liver injured easily in children since ribs are compliant, force transmitted. Liver not as developed in children, with weaker connective tissue framework. Iatrogenic injuries by biopsies, biliary drainage, TIPS, can cause capsular tears and bile leaks, fistulas, hemoperitoneum.

Injuries Subcapsular hematoma or intrahepatic hematoma. Laceration Contusion Hepatic vascular disruption Bile duct injury 86% of injuries have stopped bleeding at time of exploration. Decreased transfusion req.With conservative.

Injuries Mild hepatic injuries involving < 25% of one lobe heal in 3 mos. Moderate injuries involving 25-50% of one lobe heal in 6 mos. Sever injuries require 9-15 mos to heal. Gallbladder injuries rare, with contusons being most common, avulsions next most.

Anatomy Cantile described main divisions along a main plane from GB fossa to IVC. Divides liver into equal halves. Couinaud developed 4 sectors and 8 segments, divided into vertical and oblique planes, defined by the 3 main hepatic veins and transverse plane thru right and left portal branches.

Anatomy Hepatic veins lie between segments. Left hepatc vein divides left lobe into medial and lateral segments. Middle hepatic vein divides liver into left and right lobes.

Anatomy Right hepatic vein divides right lobe into anterior and posterior segments. A horizontal line thru left and right main portal veins is used to divide lobes into inferior and superior segments. The 8 liver segments are numbers clockwise on the frontal view.

Liver Segments

Liver Segments

Clinical Details Symptoms of injury are related to blood loss, peritoneal irritation, RUQ tenderness, and guarding. Unrecognized delayed abcess Bilomas Signs of blood loss may dominate the picture.

Clinical Details Elevated liver tests Biliary peritonitis (nausea, vomiting, abd pain). DPL has high sensitivity, 1-2% complication rate. Plain x-rays non-specific. CT scan diagnostic procedure of choice. Hida for leaks, angio for hemorrhage.

Limitations FAST sensitivity highest (98%) for grade 3 injuries or greater. Negative findings do not exclude hepatic injury. Emergency sono findings demonstrating free fluid, parenchymal injury, or both demonstrate overall sensitivity for detection of blunt abdominal trauma of 72%. Angiogram may fail to detect active bleeding.

CT Scans Accurate in localizing the site of liver injury, associated injuries. Used to monitor healing. CT criteria for staging liver trauma uses AAST liver injury scale Grades 1-6 Hematoma,laceration,vascular,acute bleeding,gallbladder injury,biloma.

Classification I-Subcapsular hematoma<1cm, superficial laceration<1cm deep. II-Parenchymal laceration 1-3cm deep, subcapsular hematoma1-3 cm thick. III-Parenchymal laceration> 3cm deep and subcapsular hematoma> 3cm diameter.

Classification IV-Parenchymal/supcapsular hematoma> 10cm in diameter, lobar destruction, or devasularization. V- Global destruction or devascularization of the liver. VI-Hepatic avulsion

Angiography Demonstrates active bleeding Transcatheter embolization may be the only treatment required. Findings include contusion, laceration, hematoma, pseudoaneurysms, fistulas. Embolization can reduce transfusion requirements, stenting for fistulas.

Angiography

Grade I Liver Injury

Grade II Liver Injury

Grade III

Grade IV

Grade V