The Effect of Low Dose Nitroglycerin on Hemodynamics and Local Liver Perfusion Following an Occlusion and Reperfusion of the Hepatic Artery and Portal Vein in Experimental Dogs

Abstract

Background: To reduce massive blood loss during a hepatectomy, many anesthesiologists have used the technique of low central venous pressure maintenance by administration of low dose nitroglycerin (NTG) and/or intravenous fluid reduction. However, so far there have been no studies about local liver perfusion (LLP) changes after hepatic artery (HA) or portal vein (PV) reperfusion in patients receiving nitroglycerin administration. In this study, the changes in hemodynamics and LLP following HA and PV reperfusion along with low dose (2/kg/min) NTG administration in dogs were observed. Methods: A total of 20 mongrel dogs were divided into four groups; HA occlusion and reperfusion group (H, n = 5), NTG administration group during the reperfusion on H (H-NTG, n = 5), PV occlusion and reperfusion group (P, n = 5), NTG administration group during the reperfusion on P (P-NTG, n = 5). After femoral and pulmonary arterial catheterization, a midline abdominal incision was made. HA and PV were exposed to clamp and declamp. A thermal diffusion microprobe was inserted in the liver parenchyme to measure LLP. Results: The PV blood flow was not changed after HA occlusion, but HA blood flow increased after PV occlusion. The LLP decreased after HA and PV occlusion. The LLP recovered to the baseline level in group H-NTG after HA reperfusion, but the LLP was more increased compared to the baseline level in group H. In group P, the LLP did not recover after PV reperfusion, but the LLP in group P-NTG recovered to the baseline level after PV reperfusion. Conclusions: In conclusion, it was observed that the LLP recovered to the baseline level by administration of NTG after PV reperfusion. However, the LLP did not increase after HA reperfusion by administration of low dose NTG.