Aortic cross-clamping during surgery of the thoracic aorta may result in paraplegia or kidney failure. Difficulties associated with external shunts and bypasses have limited their use. Therefore we compared intraluminal shunting to the nonshunting method of repair in neonatal pigs. Blood flow to the spinal cord and viscera was measured with radiolabeled microspheres before, during, and after thoracic aortic cross-clamping or shunting. Two no-shunt groups were studied: One group was clamped distal to the left subclavian artery for 30 minutes and the other for 1 hour. In the intraluminal shunt group, a shunt was placed in the aorta just below the ligamentum arteriosum for 1 hour; it was then removed and the aorta repaired. In the no-shunt groups, there was virtually no blood flow to the lower cord and viscera during the cross-clamp period. Hyperemia of the lower thoracic and lumbar cord occurred in the no-shunt 30-minute group 15 minutes after clamp removal. In the no-shunt 60-minute group, flow initially returned to the lumbar cord but then declined; and after 1 hour of reperfusion it was significantly lower than baseline. Renal blood flow was even more severely affected in the no-shunt 60-minute group, with minimal recovery during the reperfusion period. In the intraluminal shunt group baseline spinal cord and visceral blood flow were maintained during thoracic aortic cross-clamping, without the problems associated with extracorporeal circulation.

Animals↗

PubMedDate not supplied

Traumatic rupture of the aortic isthmus: an emergency?

The objectives of this study were to explore the hypotheses that: (1) patients with traumatic rupture of the aortic isthmus (TRA) who have not exsanguinated into the pleural cavity upon hospital presentation are unlikely to develop rupture of the hematoma during the time necessary to investigate all injuries and attend to those of more immediate danger; and (2) appropriate medical therapy can prevent free rupture of the hematoma. The medical records of 112 patients who were proved to have TRA at the isthmus resulting from injury within the preceding 7 days were reviewed. Fifty of these patients received medical treatment aimed at decreasing aortic wall stress; 46 were managed under a formal protocol. The available English language and European literature for the past 15 years was surveyed for evidence of the effects of delay between injury and aortic repair. Eight patients died before aortic repair, six of aortic exsanguination (all within 4 hours of injury). Of 77 patients for whom the time of injury was recorded and the aorta was repaired, 36 were repaired within 12 hours of injury and 41 between 12 hours and 24 weeks; none developed aortic hemorrhage. No patient receiving adequate medical therapy died of rupture of the hematoma. Other major surgery preceded aortic repair in 33 patients. We conclude that the concept that traumatic rupture of the aorta should always take priority over other injuries is incorrect. Pharmacologic reduction of wall stress appears to decrease the probability of rupture of the periaortic hematoma.

Adolescent↗

PubMedDate not supplied

Cervicothoracic arterial injuries: recommendations for diagnosis and management.

Management of arterial injuries at the thoracic outlet and neck presents a major challenge to the trauma surgeon: hemorrhagic shock, neurologic deficit, and limb loss are the serious sequelae. Over a 13-year period, 118 patients with injuries to the innominate, carotid, subclavian, and axillary arteries were evaluated. Most injuries were penetrating (78%). Half of the patients were diagnosed by physical examination and half by angiography. Patients were treated by either primary repair (35%), interposition graft (31%), ligation (8%), or anticoagulation (26%). Two patients required amputations (1 digit, 1 above elbow). Overall mortality was 14%, with 5% due to consequences of hemorrhagic shock, 7% due to cerebral ischemia, and 2% due to other causes. Claviculectomy, median sternotomy, and trap door incisions were routinely used for proximal vascular control and repair. We conclude that liberal use of angiography is indicated in stable patients for penetrating wounds near major arteries, and for blunt injuries associated with neurologic deficits unexplained by computed tomography. Patients with obvious arterial injury should have immediate exploration. Extensile exposure is mandatory for appropriate management. Blunt carotid dissections are generally best managed non-operatively with anticoagulation.

Adolescent↗

PubMedDate not supplied

Perfluorocarbons: future clinical possibilities.

Perfluorocarbons are now being used as oxygen carriers in clinical settings. Because these chemicals may have a role as a blood substitute, in organ preservation, and in the management of respiratory failure, we have reviewed some of the research leading to these applications.

Biological Transport↗