Triple-contrast computed tomography in the evaluation of penetrating posterior abdominal injuries.

Routine exploration of stable patients who have penetrating injuries of the posterior abdomen results in a high rate of unnecessary operation. Prolonged observation, while safe, is expensive and potentially morbid in the event that a retroperitoneal injury has occurred and treatment is delayed. To evaluate these injuries, we have developed and employed a protocol for computed tomographic (CT) scanning of the abdomen employing oral, intravenous, and rectal administration of contrast material to visualize the retroperitoneal contents. Between Jan 1, 1985, and Dec 1, 1986, 40 patients were studied in this manner. In each case, the path of penetration could be determined exactly by tracing the course of air and hematoma through the tissues. All retroperitoneal organs could be evaluated well enough to exclude injuries requiring intervention. The majority of patients showed subcutaneous penetrations only. All six significant intra-abdominal injuries were diagnosed correctly and confirmed at laparotomy. All 34 patients deemed by CT not to have significant injury were observed for 72 hours, and all were discharged uneventfully. Triple-contrast CT appears to be of great value in the triage of penetrating posterior abdominal trauma into operative and nonoperative groups.