Canine model of acute aortic rupture: treatment with percutaneous delivery of a covered Z stent--work in progress.

PURPOSE: To develop a percutaneous treatment for aortic rupture with use of a covered intraluminal stent.

MATERIALS AND

METHODS

A transmural tear was created percutaneously in the thoracic aorta in six dogs with use of a 4-mm angioplasty balloon. Gianturco Z stents were covered with polytetrafluoroethylene, loaded into a 14-F sheath, and advanced through the femoral artery to the site of injury. Within 2 minutes after initiation of the injury, the stent was deployed. Homologous canine blood was given during the procedure. Dogs that survived 24 hours were then killed.

RESULTS

The first stent did not expand completely, and the dog died in 1 hour. At necropsy, the first two dogs (1-hour and 8-hour survival) had a large left hemothorax and extensive periaortic hematoma, indicating intrathoracic exsanguination. The next four dogs were treated with a modified stent and survived 2 hours (n = 1), 8 hours (n = 1), and 24 hours (n = 2). At necropsy hemothorax did not exceed 15 mL, and periaortic hematomas were small. The cause of death in the two early casualties with the modified stent is uncertain. There were no signs of spinal cord injury despite occlusion of three pairs of intercostal arteries.

CONCLUSION

The covered Z stent (in its modified form) tamponaded the aortic tear, preventing exsanguination. Long-term studies of biocompatibility of this device appear justified.