Production of animal model of traumatic pseudoaneurysm

Three microsurgical techniques, i.e., electric cauterized vein patch (ECVP), electric cauterized vein segment (ECVS), and electric cauterized muscular cavity (ECMC), were employed to produce an ideal animal model of traumatic pseudoaneurysm (TPA). In this paper, 108 cases of TPAs were produced in rabbit femoral arteries. The successful rates of these microsurgical techniques, proved by angiography, autopsy in vivo, and histological examination, were 5.5, 16.7, and 88.9%, respectively. The successful rate of ECMC, with the merits of simple operation, a narrow neck but giant size of TPA which rarely ruptured, and the pulsatile mass occurring as early as 4 to 11 days after operation, was much higher than that of ECVP and ECVS (P < 0.01). By this reliable method of ECMC, the pathogenesis of TPA was observed as the following: the arterial wall was injured and partly ruptured, then the escaped blood was confined by fibrous connective tissue near the arterial opening. As a result, a located hematoma without any pulsatile mass and vascular systolic murmur formed. When a cavity occurred in the hematoma a few days later it gradually enlarged till the clot which plugged the arterial opening became so thin that arterial blood flowed into the cavity to form a pulsating hematoma. So, a pulsatile mass with vascular systolic murmur can be observed.