HEMODYNAMIC-STUDIES AND ESOPHAGEAL MORPHOMETRIC ANALYSES IN PORTAL HYPERTENSIVE RATS WITH LEFT ADRENAL VEIN LIGATION

Background. Despite many attempts to create esophageal varices in expe rimental animals, most of them have failed. This study investigated wh ether rats with partial portal vein ligation (PVL) and left adrenal ve in ligation (LAL) develop hyperdynamic circulation and dilated esophag eal submucosal veins as compared with sham-operated (Sham) plus LAL ra ts. Methods: Two series of experiments were performed to measure (a) s ystemic and portal hemodynamics and (b) the cross-sectional area of es ophageal submucosal veins in Sham, PVL, Sham plus LAL, and PVL plus LA L rats. Hemodynamic studies with a thermodilution technique and esopha geal 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 si gnificantly higher cardiac index and portal pressure than Sham rats wi th or without LAL (P < 0.05). LAL did not induce changes in mean arter ial pressure, cardiac index, systemic vascular resistance, heart rate, or portal pressure in either Sham or PVL rats (P > 0.05). The mean cr oss-sectional area of esophageal submucosal veins in PVL rats with LAL (7340 +/- 833 mu m(2)) was significantly larger than that in Sham rat s with LAL (4236 +/- 556 mu m(2); P < 0.05). There was no significant difference in the mean cross-sectional area of esophageal submucosal v eins between PVL. and Sham rats without LAL. Conclusions: PVL rats wit h LAL developed hyperdynamic circulation similar to PVL rats without L AL. In addition, PVL plus LAL rats had larger esophageal submucosal ve ins than Sham plus LAL rats. This study shows that the esophageal subm ucosal veins of the 14-day partially portal vein-ligated rats with LAL resemble the structural abnormalities observed in human esophageal va rices, suggesting that this model could be useful to investigate this entity.