The two-in-one model: a new variation of the arteriovenous malformation model in swine

Abstract

We report a new variation of the well-established experimental arteriovenous malformation (AVM) model in swine. To provide high flow through the rete mirabile (nidus, RM) and thereby to reduce the rate of spontaneous thrombosis of the AVM, we performed an end-to-end anastomosis of the left common carotid artery (CCA) and the external jugular vein (EJV) microsurgically in three micropigs. After 1 and 4 months the animals underwent angiograms of the CCA and vertebral artery (VA). In all cases the diversion of the blood through the RM was patent, up to the 4 months follow-up. We observed an arteriovenous fistula (arteriovenous pseudomalformation, pAVF) between the VA and the EJV in each case at both 1 and 4 months. This modification of the well-known AVM model in the micropig could be used to monitor long-term changes after embolisation, avoiding the naturally high rate of spontaneous thrombosis. This two-in-one model is thus well suited for preclinical testing of embolic materials.

Animal Models in Studying Cerebral Arteriovenous Malformation

“…Based on Massoud's model, modified swine AVM models were introduced. They posed a higher pressure gradient closer to values found in human AVMs, thereby reducing the rate of spontaneous thrombosis in the rete [ 59 , 60 ].…”

Most Promising Approaches to Improve Brain AVM Management: ARISE I Consensus Recommendations

“…Based on Massoud's model, modified swine bAVM models were introduced, increasing the pressure gradient closer to values found in humans, and thereby reducing the rate of spontaneous thrombosis in the rete. [117][118][119] Recent swine angiogenesis models have created an occlusion of the common carotid artery, with a significant increase in the volume of the rete mirabile and histological changes of angiogenesis similar to those seen in bAVMs. 120 These models have also been tested with pharmacological treatments, such as intra-arterial injection of bevacizumab, which resulted in decreased endothelial proliferation, but no change in vascular diameter.…”

Experimental Animal Models of Arteriovenous Malformation: A Review

“…Swine are preferred for their large neck vessels, which allow for faster and easier fistula creation. There are models in which external arteries need not be occluded [ 26 , 27 ]. An end-to-end anastomosis instead of a side-to-side anastomosis shows an increase in blood flow in the rete mirabile.…”

“…An end-to-end anastomosis instead of a side-to-side anastomosis shows an increase in blood flow in the rete mirabile. Spontaneous occlusion does not occur as in previous models, which means these could be used for research that involves a longer duration [ 23 , 24 , 26 , 27 ]. Additional advantages with swine model are that the swine coagulation system is similar to humans and they are inexpensive [ 24 ].…”