Liver ABSITE Questions

*Liver

Anatomy Replaced Right hepatic artery - off SMA (in hepato-duodenal ligament laterally) (20%) Replace Left hepatic artery - off left gastric (in gastro-hepatic ligament) (15%) Replaced Common hepatic artery - off SMA (2%) QUESTION: Hepatic artery and portal vein supply how much blood flow respectively? and which one mainly feeds cancer mets? ANSWER: 25% / 75% but hepatic artery mainly supplies mets. QUESTION: What is compressed with a pringle maneuver and how long can this be held? ANSWER: portal vein posterior, common bile duct laterally, hepatic artery medially - 30 minutes QUESTION: Why are zone III acinar cells more prone to ischemia? ANSWER: Zone I cells are near the artery, bile duct, and portal vein branch and thus are exposed to more toxins but get a better blood supply whereas zone III cells are around the hepatic vein branch and thus are more prone to ischemia but less toxins. Bile and Bilirubin - Hemoglobin broken down to bilirubin; Bilirubin conjugated by glucuonyl transferase in liver and secreted in bile; conjugated bilirubin broken down by bacteria in terminal ileum to urobilinogen and reabsorbed in blood and excreted in urine (thus high levels will turn urine cola dark) - Bile composed of bile salts, lecithin, cholesterol and bilirubin; Primary bile acids: cholic acid and chenodeoxycholic acid and Secondary bile acids: deoxycholic and lithocholic acids formed by anaerobic bacteria in the intestine QUESTION: What increases bile acid synthesis? ANSWER: ileal resection, by-pass, bile acid absorption inhibitors (Cholestyramine) Jaundice Unconjugated - Gilbert's (diminished glucuronyl transferase); Crigler-Najjar (glucuronyl transferase deficiency); Physiologic newborn (immature glucuronyl transferase) Conjugated - Obstruction, Rotor's (inadequate storage); Dubin-Johnson (poor secretion) QUESTION: In a patient with elevated direct hyperbilirubinemia due to obstruction, why would INR be elevated? ANSWER: Bile helps absorb fat and Vitamin K is a fat soluble vitamin that is needed for the extrinsic clotting factor coagulation Benign Liver Tumors - Hemangioma - MOST COMMON, Peripheral to central enhancement, hypervascular, Do nothing unless giant or symptomatic/consumptive (Kasabach-Merritt syndrome) - Adenoma: HEMORRHAGE RISK and malignant transformation risk, usually young women on birth control, stop birth control pills and if same size, then resect - Focal Nodular Hyperplasia: CENTRAL STELLATE SCAR, sulfur colloid scan positive although MRI usually diagnositc, no need for surgical resection. QUESTION: Most common benign liver lesion? ANSWER: Hemangioma QUESTION: First step in management of hepatic adenoma?  If that doesn't work then? ANSWER: Stop birth control pills, then resection Malignant Liver Tumors - Hepatocellular: #1 WORLDWIDE Cancer due to Hepatitis C; Resection or transplantation for Milan Criteria (one lesion < 5cm, 3 lesions < 3, no mets, no vascular invasion) QUESTION: Marker associated with HCC? ANSWER: AFP (correlates with tumor size) QUESTION: What percentage of colon cancer cases are eligible for liver met resection and what is 5 year survival after liver met resection? ANSWER: 10% and 20% 5 year survival Liver Abscess - Pyogenic: MOST COMMON, perc drain and ABX, mostly from cholangitis, diverticulitis, appendicitis, usually GNR (E.coli) - Amebic: due to Entamoeba histolytic (from Mexico), flagyl and perc drain if toxic - Echinococcus: positive indirect hemagglutination, preop albendazole, surgical removal with etoh injection to avoid anaphylactic shock - Schistosomiasis - prizquantel, associated with variceal bleeding, may need surgery to control bleeding QUESTION: Historically what was the main cause of pyogenic abscesses? what is it now? ANSWER: Bowel infection (diverticulitis/appendicitis) but now is bilary tract disease (cholangitis) QUESTION: What is the best way to differentiate between different types of liver abscesses? ANSWER: CT scan Budd-Chiari Syndrome occlusion of hepatic vein and IVC from web/membrane (Africa/Asia) or clot (western countries) QUESTION: rapid-onset ascites with RUQ pain, liver failure and bloody abdominal tab - Diagnosis? and Treatment? ANSWER: Budd-Chiari syndrome by duplex ultrasound; anticoagulation