Asanguinous hypothermic liver perfusion in dogs

Biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps

Isolated organ perfusion is used in clinical practice for chemotherapy in adults with malignant tumors. However, it has not been performed in children because of the size mismatch with the adult circuits. The authors have previously studied isolated liver perfusion in small animals using the self-regulating extracorporeal membrane oxygenation circuit. The present study was designed to investigate the biochemical and morphological changes in the liver during isolated liver perfusion with double bypass using automatic blood pumps. Isolated liver perfusion was performed with bypass between the hepatic and portal veins in seven weanling Yorkshire swine weighing 8.2 to 12.2 kg, at a flow rate of 20 mL/min/kg for up to 4 hours. Venous blood from the intestine and lower body was bypassed to the superior vena cava. As a result, perfusate glutamic pyruvic transaminase and lactate concentrations did not change during liver perfusion. On gross inspection, the surface of the liver was mottled. Microscopically, normal histology of the hepatic parenchyma and portal tract structures was preserved. Transmission electron microscopy showed no gross structural abnormalities in most of the hepatocytes for up to 4 hours. However, swelling of the mitochondria and smooth endoplasmic reticulum was seen occasionally in a very small number of the hepatocytes after more than 3 hours of perfusion. Glycogen granules decreased with time in some animals. Isolated liver perfusion at 20 mL/min/kg of perfusion flow can be performed safely for up to 4 hours with nearly intact hepatocellular function and morphology.

Hepatic vein and retrohepatic vena caval injury

Retrohepatic venous injury presents as a rare but frequently lethal complication of trauma. The anatomic arrangement makes management of these injuries difficult at best. Operative exposure and isolation techniques ranging from cross-clamping the aorta, portal triad, suprarenal vena cava, and suprahepatic vena cava to the use of internal shunts are described in this report. Our experience from 1968 to 1987 with internal shunting techniques includes 27 patients. We have successfully resuscitated 12 patients for an acute mortality of 55%. We believe that this figure is high but compares favorably with published results. Late deaths from sepsis, disseminated intravascular coagulation, or multiple systems organ failure remain as significant causes of overall mortality. Many techniques have been successfully employed over the years in achieving vascular isolation of the liver. The methods all have their own merits, but the key factor in each is the recognition that they need to be employed. Conservative selection of patients is undoubtedly justified, but aggressive approaches should not be delayed until they are the methods of last resort.

A technique for isolation perfusion of the canine liver with survival

A technique of isolation perfusion of the canine liver was developed as a model for treating cancer limited to the liver. Preservation of hepatic functional integrity was dependent on maintenance of near physiologic conditions for the perfusion. Flow to the liver, 1 ml/min/g, was provided by gravity to the portal vein at two thirds total flow, and by pump to the hepatic artery at one third total flow. Utilizing the technique described, six dogs died 4-12 hr after a 1-hr perfusion. The dogs received Ringer's lactate solution IV and had a rising blood lactate to greater than 9 mM and a rising lactate/pyruvate ratio. After changing IV fluids to nonlactate containing solutions, 4/6 dogs survived a 1-hr perfusion at 37 degrees. Blood lactate concentrations remained below 6 mM (alpha less than 0.05) during perfusion, and the lactate/pyruvate ratios remained in a physiologic range on comparison to the nonsurvivors (alpha less than 0.05). Mild elevations occurred in the SGOT and SGPT with the peak on the first postoperative day of 93 +/- 54 and 79 +/- 56, respectively, but returned to normal within 4-7 days. Perfusate chemistries lactate, pyruvate, glucose, total alpha-amino acids, ketone bodies, SGOT, and SGPT demonstrated that hepatic functional integrity was maintained during the 1-hr perfusion. Hepatic function as assessed was no different between survivors and nonsurvivors. Hypoglycemia (glucose less than 2 mM) contributed to the two deaths. Tolerance of the dog to the temporary anhepatic state may be the limiting factor to prolonged perfusions.

Results following hypothermic asanguineous liver perfusion in dogs

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