Nonoperative observation of clinically occult arterial injuries: a prospective evaluation.

Forty-seven patients with 50 clinically occult injuries of major arteries were studied prospectively to determine the natural history of these lesions and the safety of nonoperative management. Penetrating trauma was the predominant mechanism and lower extremity arteries were most commonly involved. The morphology of these arterial injuries included 22 cases of intimal flaps, 21 cases of segmental arterial narrowing, 6 pseudoaneurysms, and 1 acute arteriovenous fistula. There was one death as a result of unrelated causes and another three injuries operated on immediately after arteriographic diagnosis. The remaining 46 injuries were followed up nonoperatively by serial arteriography (39) or clinical examination (7) during a mean interval of 3.1 months (range, 3 days to 27 months). Complete resolution was documented for 29 injuries (63%), whereas 3 improved, 9 remained unchanged, and 5 worsened during the period of follow-up. All worsened cases involved small or occult pseudoaneurysms that subsequently enlarged and then underwent immediate surgical repair without subsequent morbidity. Because 89% of the followed injuries never required surgery, nonoperative observation appears to be a safe and effective management option for clinically occult arterial injuries.