Management of Complications of Chronic Liver Disease: “When to Refer to Transplant?” Philip Rosenthal, M.D Professor of Pediatrics & Surgery University of California, San Francisco THE LIVER • • • • Largest organ in body RUQ of abdomen Sheltered by rib cage In adult, weighs lbs LIVER: GROSS ANATOMY • Separated into lobes: Right and Left • Right lobe is ~6X larger than the left • Porta hepatis is entry site for blood vessels and exit site for bile ducts Liver Transplantation • • • • Anatomical segments Living-related Split Reduced-sized Split liver HEPATIC CIRCULATION • A dual blood supply • Portal vein drains intestines and spleenprovides 75% of liver’s blood supply • Hepatic artery supplies oxygenated blood from aorta-provides 25% of blood supply CELLULAR ARCHITECTURE • Portal vein and hepatic artery branch within the lobes to form sinusoids that run parallel to rows of hepatocytes (liver cells) • Sinusoids allow exchange of substances to liver cells CELLULAR ARCHITECTURE • Hepatocytes are most abundant and metabolically active • Kupffer cells in the sinusoids are scavenger cells for foreign matter, wornout blood cells and bacteria CELLULAR ARCHITECTURE • The liver is organized into polyhedral unitslobules • On cut section, a lobule is hexagonal with portal triads at the periphery • Portal triad-branch of hepatic artery, portal vein, bile duct REGENERATIVE ABILITY • Hepatocytes rarely divide but have the capacity to reproduce in response to appropriate stimuli • This process can restore the liver to within 5-10% of its original weight • Liver regeneration plays an important role after surgical resection or after injury that destroys portions of the liver LIVER FUNCTIONS • Purification, transformation and clearance of: – – – – – ammonia bilirubin hormones drugs toxins Portal Hypertension: Pharmacologic • Somatostatin and Octreotide • Somatostatin, 14-amino acid peptide – Reduces splanchnic blood flow by selective mesenteric vascular smooth muscle constriction – Short half-life complicates its use • Octreotide – Can be given sq but best given IV drip (25-50 μg/m2/hour or 1.0 μg/kg/hour) • Both drugs achieve excellent results in controlling bleeding in adult trials- no trials in children Portal Hypertension: Pharmacologic • Beta-Blockers • No role in acute bleeding, useful for prophylaxis • Decrease heart rate by 25%- decreases cardiac output, portal inflow • In adults, efficacy assessed in patients: – with documented varices to prevent 1st bleed (primary) – Folowing 1st bleed to prevent further bleeds (secondary) • In primary prophylaxis, 3.9% vs 21.6% control • In secondary prophylaxis, controversy: – In Child A 3%, but in Child B or C 46-72% Portal Hypertension: Pharmacologic Βeta−Blockers in Children • Decrease heart rate by 25%- decreases cardiac output, portal inflow • Shashidhar et al JPGN 1999;29:12 7/21 (33%) bled on propranalol Rx, 2/21 (10%) noncompliant, 4/21 (19%) inadequately dosed • Ozsoylu et al Turk J Pediatr 2000;42:31 Propranalol efficient for preventing 1st bleed, but only useful in Child-Pugh A children to prevent recurrent bleeding Portal Hypertension • Mechanism: increased resistance to blood flow from the visceral or splanchnic portal circulation to the right atrium • Presinusoidal obstruction does not cause impairment in hepatic synthetic function • Treatment for presinusoidal obstruction should be directed toward prevention of hemorrhage while spontaneous collaterals develop Portosystemic Shunting • Intrinsic liver disease minimal - relatively intact function • Refractory variceal hemorrhage • Pre-emptive for renal transplant in severe portal hypertension • Careful consideration for future renal or liver transplant Portal Hypertension: Interventions • Primary vs secondary prophylaxis • Activity restrictions (weight lifting) ã ò-blockade: propranalol ã Band ligation ã Surgical shunt • Immunization issues – Pneumococcal, menigococcal Portal Hypertension: Sclerotherapy • 5% ethanolamine, 1-5% tetradecyl sulfate, 5% sodium morrhuate • 3-6 sessions over 2-4 weeks • Complications: retrosternal pain, fever, dysphagia • Esophageal ulcers at injection site 70-80% • Esophageal strictures, perforation or mediastinitis in 10-20% Portal Hypertension: Sclerotherapy • In children with extrahepatic portal hypertension, recurrent variceal bleeding developed in 31% over 8.7 years (Stringer et al Gut 1994;35:257) • In children with intrahepatic disease, recurrent variceal bleeding developed in 75% (Fox et al JPGN 1995;20: 202) Portal Hypertension: Band Ligation • In children, variceal obliteration in 73-100% • Recurrence in 75% with intrahepatic disease • Small size of child’s esophagus limits number of O-rings that can be placed in session • Below y.o the thinness of esophageal wall makes full-thickness ligation a riskcontraindicated