Hemodynamic assessment during auxiliary heterotopic liver transplantation with portal vein arterialization in a Swine model: preliminary report of 10 transplants.

UNLABELLED: Portal vein arterialization (PVA) is a technical variation of auxiliary heterotopic liver transplantation (AHLT) that is rarely studied but that simplifies the AHLT surgical technique because it does not act on the portal area. The objective of this study was to analyze the hemodynamic consequences of this auxiliary transplant in an experimental model. MATERIALS AND METHODS: Ten AHLT-PVA were analyzed in a pig model. A PiCCO (Pulsion) monitor was used for the hemodynamic study of the recipient. The following were measured: cardiac index, (CI), systemic vascular resistance index, (SVRI), mean arterial pressure (MAP), global end-diastolic volume, central venous pressure, and intrathoracic blood volume. The measurements were taken at four times during transplant: at baseline, after inferior vena cava clamping, after graft reperfusion, and at closure. RESULTS: After graft reperfusion there was a reduction in SVRI (968 +/- 168.03 vs 1686.25 +/- 290.66; P < .05) and in MAP, and there was an increase in CI. At the end of the transplant MAP and SVRI recovered (1254.2 +/- 225.79 vs 968 +/- 168.03; P < .05) but CI remained slightly high. The end-diastolic volume showed greater variation than central venous pressure, although this was only statistically significant at the inferior vena cava clamping phase (244.75 +/- 52.05 vs 333.37 +/- 170.13; P < .05). DISCUSSION: Heterotopic liver transplantation with portal arterialization is well-tolerated hemodynamically. Graft reperfusion decreases SVRI and increases CI to compensate for this. This behavior, which in healthy recipients like ours is not a problem, could imply a contraindication in patients with a prior hyperdynamic state.

Doppler ultrasonographic and scintigraphic assessment of an auxiliary heterotopic liver transplantation with portal vein arterialization in pigs.

OBJECTIVE: Our aim was to evaluate liver graft integrity and function using scintigraphy and ultrasonography in a porcine model of auxiliary heterotopic liver transplantation with portal vein arterialization (AHLT-PVA). MATERIALS AND METHODS: Using Doppler ultrasonography we evaluated eight AHLT-PVA by parenchymal echogenicity, portal and arterial anatomy, and portal and biliary system flow. Two types of scintigraphy were performed: microaggregated human albumin colloid scintigraphy and diisopropyl iminodiacetic acid (DISIDA) scintigraphy, both labeled with 99mTc. RESULTS: The animals were distributed into two groups. The first group consisted of three animals with clinical suspicion of graft dysfunction, in which the ultrasonographic study revealed areas of parenchymal destructuring. In the scintigraphic study, heterogenous uptake was observed; there was no uptake in one animal. Necropsy of these three animals revealed areas of graft necrosis. The second group consisted of five animals with good clinical evolutions, in which the ultrasonographic study showed portal dilation, portal flow with arterial spiculations, and homogenous echogenicity of the hepatic parenchyma. The scintigraphic study revealed homogenous uptake by the graft and an elimination speed of the hepatobiliary agent similar to that of the native liver. CONCLUSIONS: An heterogenous echostructure of the graft provided a sign of poor prognosis indicating necrosis in the same way as heterogenous uptake or nonuptake of radioisotope upon scintigraphy. Scintigraphy is a good method to evaluate biliary function and bile elimination. In an AHLT-PVA, the main ultrasound findings derived from arterialization were dilation of the portal system and portal flow with arterial spiculations.

Description of a new auxiliary heterotopic partial liver transplantation technique with portal vein arteriolization of applicability in heterotopic liver xenotransplantation.

OBJECTIVE: The aim of this study was to describe a new model of auxiliary heterotopic partial liver transplantation with portal vein arterialization. MATERIALS AND METHODS: Three standard hepatectomies were performed in pigs. The left lateral lobe was surgically resected and portal vein arteriolization constructed by an end-to-side "Y" anastomoses between the distal to the celiac axis aorta and the portal vein. RESULTS: The graft was placed in the left iliaca fossa using anastomoses of the donor infrahepatic inferior cava vein end-to-side to the host infrarenal inferior vein and the donor aortic stump with portal vein arteriolization end-to-side to the left iliac artery. After graft reperfusion, the 3 recipients showed intraoperative hypotension, which was treated with fluid administration and vasoactive drugs. At the end of the operation, the graft displayed normal arterial blood flow and good venous drainage. The donor liver graft appeared more red than the host liver, which was due to the increased arterial blood flow. One pig of 3 died at 24 hours after surgery, probably due to hypothermia. However, the other 2 pigs survived the procedure and remained stable. Echographic monitoring showed intrahepatic arterial expansion, which may be the result of high blood pressure due to the arteriolization procedure. CONCLUSIONS: We have developed a novel and easy to perform technique that diminishes the number of anastomoses and does not involve vessels from other organs.