TRAUMATIC LACERATION OF THE LIVER LIMITED TO THE BARE AREA - CT FINDINGS IN 25 PATIENTS

OBJECTIVE. The capsular extent of traumatic hepatic lacerations may be limited to the bare area of the liver-an area not covered by peritone al reflection. In these cases, intraperitoneal bleeding may not occur, classic peritoneal findings may be absent, and results of diagnostic peritoneal lavage may be normal. We undertook a study to evaluate the frequency, CT appearance, and significance of injury of the bare area of the liver. MATERIALS AND METHODS. We retrospectively reviewed radio logic reports of 1469 hemodynamically stable trauma patients referred for abdominal CT between January 1986 and September 1992 and selected 155 patients whose CT reports indicated hepatic injury. Retrospective review of the abdominal CT scans of these 155 patients confirmed intra hepatic laceration or contusion in all of them. The study involved the 25 (16%) patients in whom the capsular extent of injury was limited t o the bare area of the liver. RESULTS. In all cases, CT scans showed s imple or complex lacerations involving predominantly or exclusively th e posterior segment of the right hepatic lobe, with capsular extent li mited to the superomedial hepatic surface. Abnormal retroperitoneal fi ndings were present in all but two cases. Twenty-two (88%) of 25 patie nts had right-sided retroperitoneal hemorrhage or fluid collections; a drenal hematoma or periadrenal fluid was seen in 12 (48%) patients. Ab normal pericaval fluid collections were present in nine (36%). Only fi ve (20%) patients had free intraperitoneal fluid. Diagnostic peritonea l lavage, performed as a correlative procedure in four patients, revea led intraabdominal hemorrhage in one, equivocal findings in one, and n ormal findings in two. Patients who had isolated injuries of the bare area of the liver did well clinically and were discharged after an une ventful hospital stay of an average of 3 days (range, 2-7 days). CONCL USION. A small percentage of hemodynamically stable patients who have hepatic trauma may have lacerations that primarily involve the bare ar ea and that are not suspected clinically or detected by diagnostic per itoneal lavage. In these patients, CT may be helpful to show the exten t of liver injury, identify associated retroperitoneal abnormalities, and provide prognostic information.