Hemodynamic Studies and Esophageal Morphometric Analyses in Portal Hypertensive Rats with Left Adrenal Vein Ligation

Abstract

Background: Despite many attempts to create esophageal varices in experimental animals, most of them have failed. This study investigated whether rats with partial portal vein ligation (PVL) and left adrenal vein ligation (LAL) develop hyperdynamic circulation and dilated esophageal submucosal veins as compared with sham-operated (Sham) plus LAL rats. Methods: Two series of experiments were performed to measure (a) systemic and portal hemodynamics and (b) the cross-sectional area of esophageal submucosal veins in Sham, PVL, Sham plus LAL, and PVL plus LAL rats. Hemodynamic studies with a thermodilution technique and esophageal morphometric analyses were performed 14 days after the operation. Results: PVL rats with or without LAL had a significantly lower mean arterial pressure and systemic vascular resistance accompanied by a significantly higher cardiac index and portal pressure than Sham rats with or without LAL (P < 0.05). LAL did not induce changes in mean arterial pressure, cardiac index, systemic vascular resistance, heart rate, or portal pressure in either Sham or PVL rats (P ± 0.05). The mean cross-sectional area of esophageal submucosal veins in PVL rats with LAL (7340 ± 833 pm2) was significantly larger than that in Sham rats with LAL (4236 ± 556 |inr; P <0.05). There was no significant difference in the mean cross-sectional area of esophageal submucosal veins between PVL and Sham rats without LAL. Conclusions: PVL rats with LAL developed hyperdynamic circulation similar to PVL rats without LAL. In addition, PVL plus LAL rats had larger esophageal submucosal veins than Sham plus LAL rats. This study shows that the esophageal submucosal veins of the 14-day partially portal vein-ligated rats with LAL resemble the structural abnormalities observed in human esophageal varices, suggesting that this model could be useful to investigate this entity.