Experimental Study Of Endovascular Embolization Of The Traumatic Pseudoaneurysms Of Common Carotid Artery With Microcoils In Rabbits

Objective: to establish traumatic pseudoaneurysm (TPA) model of common carotid artery in rabbits and evaluate the long-term outcome of endovascular occlusion of these experimental pseudoaneurysms with microcoils(MC). Methods: A cavity was made by cauterizing the right sterno-cephalicus mUscle of each of 30 rabbits with bipolar electric coagulation forceps. The wall of the right common carotid artery opposite to the cavity was incised longitudinally, then two orifices were anastomosed by mattress suture and thus a hemotoma linked to the artery formed. All manipulation was performed microsurgically. The cavity of the hemotoma was open to it抯 parent artery due to the impact of blood flow of the parent artery on it, so a traumatic pseudoaneurysm was formed. The 16 surviving animals in which TPAs had been formed were randomly divided into 3 group 3~4 weeks after the operation: (1)control group (3 animals); (2)group of embolizing TPA cavity with MC (9 animals); (3) group of embolizing TPA parent artery with MC (4 animals). The TPAs were examined by color Doppler ultrasonography(CDU), digital subtraction angiography (DSA)and pathology 3 months following the embolization. Resutls: Twenty-six rabbits successfully received the operation and there was a pulsatile mass in the right common carotid artery in each of them 6-l2days after the operation.Eight rabbits died of rupture of the TPA 9-17 days following the operation. Eighteen TPAs were reexamined by CDU and pathological examination was performed in 2 of the 18 TPAs. These -2- examinations proved that the morphological, hemodynamic and pathologic featrues in the experimental TPAs were similar to those in human TPAs. The TPAs cavities which were completely occluded 3 months after the embolization in 4 of the 9 animals in the group of embolizing TPA cavity were filled up with scar tissue and their parent arteries remained unobstructed. The other 5 were excluded from the experiment because of the MC sliding into the parent arteries from the TPA cavities during the embolization~ CDU and DSA examinations also confirmed that the TPA cavities had been completely obliterated in all 4 animals of the group of embolizing TPA parent artery 3 months following the embolization. All the 3 animals in the control group, which had been untreated,died of rupture of the TPAs within 6 weeks after the operation. Statistic analysis showed that embolizing TPAs cavities or their parent arteries had significant therapeutic effect on the TPAs compared to control group (p=O.O29) Conclusions: The present animal model is an optimal tool for endovascular treatment research on the TPAs. TPAs during their formation phrase could be cured by embolizing their cavities or their parent arteries with MC, and the parent arteries remained unobstructed when the former was used.