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 u se of a covered intraluminal stent. MATERIALS AND METHODS: A transmura l tear was created percutaneously in the thoracic aorta in six dogs wi th 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 aft er initiation of the injury, the stent was deployed, Homologous canine blood was given during the procedure, Dogs that survived 24 hours wer e 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 he matoma, indicating intrathoracic exsanguination. The next four dogs we re 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 int ercostal arteries. CONCLUSION: The covered Z stent (in its modified fo rm) tamponaded the aortic tear, preventing exsanguination. Long-term s tudies of biocompatibility of this device appear justified.