An experimental model for the treatment of lethal bleeding injury to the juxtahepatic vena cava with stent graft.

Background: Juxtahepatic vein injuries present a high mortality rate. Our objectives were to develop an experimental model of endovascular lethal injury of the juxtahepatic inferior vena cava (JHIVC) and to evaluate its hemodynamic alterations; to treat the lesion with volume replacement, and a stent graft (SG); and to follow the animals after treatment.

Methods: Twenty dogs were anesthetized and monitored [heart rate (HR), mean arterial pressure (MAP), vesical and peritoneal pressures], and submitted to a JHIVC endovascular injury. After volume replacement the dogs were divided into two groups: control (GI) and experimental (GII). GI was observed until death. GII was treated with SG and followed by Doppler ultrasound (DUS) and cavography for 4 (GIIA), and 8 weeks (GIIB), and then sacrificed and IVC and SG were analyzed.

Results: GI presented increased abdominal pressures, arterial hypotension, and death after 80 minutes. GII had a 100% survival rate till sacrifice, without clinical repercussions. At DUS and cavography all SG were patent, with monophasic pulsatile flow. On US, SG diameters after 2, 4, and 8 weeks did not show differences. On cavography IVC diameters presented no difference between groups GIIA and GIIB throughout the experiment. These data analyzed for the GII as a whole, showed statistically significant differences. Average lumen diameter reduction of SG was 27.43+/-20,00%. Pressure values in the IVC cranially, caudally to the SG, and inside the SG, did not show differences. In the IVC with the SG we observed a thicker neointima layer, and the injury in the media layer was covered with fibroconnective tissue.

Conclusions: We developed an experimental dog model of endovascular lethal injury of the JHIVC with significant increase in abdominal pressures, and a mortality rate of 100%. The treatment of this lesion with SG resulted in a thickened neointima layer, and a 27% reduction in the JHIVC lumen diameter, without clinical repercussion, and with a 100% survival rate.