Takahiro Ito

Treatment of hepatoblastoma : Less extensive hepatectomy after effective preoperative chemotherapy with cisplatin and Adriamycin

BACKGROUND Although the prognosis of hepatoblastoma was improved by the introduction of cisplatin and doxorubicin (Adriamycin) for adjuvant chemotherapy, extensive hepatectomy continues to be the usual practice. We retrospectively reviewed our recent experience with hepatoblastoma to determine whether the new modality of intensive chemotherapy could change the resectability, extent of hepatectomy, operative complications, and prognosis. METHODS The clinical features of 15 children with hepatoblastoma treated between 1985 and 1995 were reviewed. Intensive chemotherapy was added before surgical resection not only when a tumor was unresectable but also when it was large enough to increase the risk of operative morbidity. RESULTS There was 100% resectability, and the overall mortality rate was only 6.7%. Fourteen patients have been free of disease for 2 to 12 years. Preoperative chemotherapy enabled resection of six previously unresectable hepatoblastomas. Moreover, hepatic resection tended to be less invasive in several patients whose tumors had been much reduced after preoperative chemotherapy. Intraoperative and postoperative complications were minimal, with a short operative time and small amount of blood loss, especially in the group with delayed primary operation. CONCLUSIONS The preoperative administration of cisplatin and Adriamycin reduced the tumor size so that a safe hepatectomy could be performed with less blood loss and minimal technical complications. Unnecessary sacrifice of the normal hepatic tissue was avoided by performing the less extensive hepatectomy.

Coronary arterial perfusion during venoarterial extracorporeal membrane oxygenation

The effects of venoarterial extracorporeal membrane oxygenation on left ventricular performance have not been studied in detail. Coronary arterial flow obtained by direct measurement with an electromagnetic flowmeter and blood gas analysis from the aortic root were tabulated during venoarterial extracorporeal membrane oxygenation 14 puppies, and these parameters were evaluated with respect to changes in the venoarterial extracorporeal membrane oxygenation flow. Unique automatic blood pumps generating pulsatile flow were used for the venoarterial extracorporeal membrane oxygenation bypass. Coronary arterial flow decreased as the extracorporeal membrane oxygenation flow increased (106 +/- 26 ml/min per 100 gm of left ventricle at 20 ml x min(-1) x kg bypass flow to 71 +/- 17 ml/min per 100 gm of left ventricle at 100 ml x min(-1) x kg bypass flow, p < 0.01). There were no significant changes in the mean or diastolic pressures in the ascending aorta despite changes in the extracorporeal membrane oxygenation flow. Arterial oxygen tension in the ascending aorta was not increased even under high-flow venoarterial extracorporeal membrane oxygenation. This result indicates that oxygenated blood from the extracorporeal membrane oxygenation circuit does not pass in a retrograde fashion into the aortic root and thus does not perfuse the coronary arteries. The diastolic aortic pressure did not correlate with the changes in extracorporeal membrane oxygenation flow. The decrease in coronary arterial flow is therefore predominantly caused by increased coronary arterial resistance. Tension-time index, an indicator of myocardial oxygen consumption, did not decrease with venoarterial extracorporeal membrane oxygenation. In conclusion, high-flow venoarterial extracorporeal membrane oxygenation causes undesirable hemodynamic effects on the left ventricle.

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.

Serum bilirubin fractions in cholestatic pediatric patients: Determination with Micronex high-performance liquid chromatography

Bilirubin conjugates in the serum of cholestatic pediatric patients were investigated with Micronex high-performance liquid chromatography. Serum bilirubin was resolved into four fractions: delta bilirubin (Bd), bilirubin diglucuronide (BDG), bilirubin monoglucuronide (BMG), and unconjugated bilirubin (Bu). The conjugated bilirubin (BDG+BMG) fraction in preoperative patients with biliary atresia (BA) was 48.8 +/- 5.1%, which was significantly higher than that in patients with infantile hepatitis (P < .01). Among postoperative BA patients who recovered from jaundice, the Bd fraction increased during the first month, remained elevated (60% to 80%) for a while, and then gradually decreased. After 6 months, the Bd fraction decreased to 30% in the jaundice-free survivors, but was still higher than that in controls (7%). Even after the total serum bilirubin had normalized (< or = 1.0 mg/dL), distribution of bilirubin fractions remained abnormal, possibly reflecting impaired hepatic excretion of bilirubin. In conclusion, measurement of the conjugated bilirubin fraction enabled BA to be differentiated from infantile hepatitis, and the delta bilirubin fraction proved to be an important indicator of cholestasis in postoperative BA patients with normal serum bilirubin.