Liver surgery

Liver anatomy , physiology , pathologies and surgery

1. The liver

2. History of liver surgery Ancient Greek , hepar , derives from the verb hepaomai , which means “mend” or “repair.” The ancient Greek myth of Prometheus reminds us that the liver is the only organ that regenerates. principles are correct that after hepatic resection, the remnant liver will hypertrophy over weeks to months to regain most of its original liver mass . what is the maximum amount of liver that can be resected while retaining adequate liver function ?

3. Liver before and after auto repair

4. Liver Innervation * Parasympathetic : Anterior liver  Lt Vagal Branch Posterior Liver  Rt Vagal Branch * Sympathetic : - Greater Thoracic splanchnic & celiac branches.

5. Lymph Drainage Lymph is produced within the liver  perisinusoidal space of Disse  hilar cystic duct lymph node ( Calot’s triangle node), common bile duct, hepatic artery, and retropancreatic and celiac lymph nodes.

6. Calot’s node - “ hilar node”

7. Calot’s triangle

8. Liver Physiology These include processes such as storage, metabolism, production, and secretion. One crucial role is the processing of absorbed nutrients through the metabolism of glucose, lipids, and proteins . The liver maintains glucose concentrations in a normal range over both short and long periods and in the fasting state. by performing several important roles in carbohydrate metabolism. ( Glycogenolysis ,gluconeogenesis ,glycogen synthesis or glycolysis and lipogenesis .) The liver also plays a central role in lipid metabolism through the formation of bile and the production of cholesterol and fatty acids . Protein metabolism occurs in the liver through amino acid deamination, resulting in the production of ammonia as well as the production of a variety of amino acids . the liver also is responsible for the synthesis of most circulating plasma proteins . (albumin , factors of the coagulation and fibrinolytic systems, and compounds of 2 the complement cascade. the detoxification of many substances through drug metabolism occurs in the

9. Bilirubin Metabolism

10. Bile Synthesis

11. Drug Metabolism

12. Liver Function Test *Hepatic Cell Injury: Aspartate transaminase (AST ) A lanine transaminase (ALT ) A lkaline phosphatase (AP ) γ- glutamyltranspeptidase (GGT ) Bilirubin * Liver Function: S erum albumin levels P rothrombin time (PT).

13. Abnormal synthetic function Liver synthetic function is best assessed by: -Albumin level -INR ( PT ) liver produces approximately 10 g of albumin per day. However, albumin levels are dependent on a number of factors such as nutritional status, renal dysfunction, protein-losing enteropathies , and hormonal disturbances.

14. Cholestasis Cholestasis is a condition in which bile flow from the liver to the duodenum is impaired, due to intrahepatic causes (hepatocellular dysfunction) or extrahepatic causes (biliary tree obstruction). detected by measuring the serum levels of bilirubin, AP, and GGT. elevated indirect bilirubin level suggests  intrahepatic cholestasis. elevated direct bilirubin level suggests  extrahepatic obstruction.

15. Jaundice Yellowish discoloration of skin , sclera and mucus membrane with the pigment bilirubin. 1) Prehepatic : ( Excessive Hemolysis – insufficient gluco ) A- genetic ( spherocytosis , leptocytosis , G6PD deficency ) B- Acquired ( coomp’s test) 2) Intrahepatic ( involve the intracellular mechanisms for conjugation and excretion of bile from the hepatocyte). 3) Extrahepatic ( extrinsic or intrinsic biliary obstruction )

16. Detectable when Bilirubin > ?? mg /dl .

17. Acute Liver Failure Rate of extent of hepatocytes damage exceed the regenerative ability of the liver. Around 2000 patient annually in U.S . Development of Hepatic Encephalopathy within 26 weeks of severe liver injury with no previous history of liver diseases or portal HTN. Before the introduction of orthotopic liver transplantation (OLT), the chance for survival was <20%. Currently, most series report 5-year survival rates of >70% for affected patients.2

18. ETIOLOGY : East  Viral hepatitis A,B,E. West  Drug & Toxins . ALF need to be monitored in the intensive care unit (ICU) setting, and specific attention needs to be given to fluid management, ulcer prophylaxis , hemodynamic monitoring, electrolyte management, and treatment of infection. Hypophosphatemia, a sign of hepatic regeneration , may indicate a higher likelihood of spontaneous recovery and needs to be corrected via intravenous (IV) administration of phosphate.

19. How to treat Acetaminophen overdose ?

20. Few Hours of presentation ?  Charcoal reduces the amount of acetaminophen in the GI tract. N - acetylcysteine (NAC )  1.orally (140 mg/kg initial dose, followed by 70 mg/kg every 4 hours × 17 doses) 2. intravenous route (loading dose of 150 mg/kg, followed by a maintenance dose of 50 mg/kg every 4 hours × 12 doses).

21. Liver cirrhosis

22. Cirrhosis & portal HTN Sustained wound healing in response to chronic liver injury  presence of fibrous septa subdividing the parenchyma into hepatocellular nodules. 40% of cirrhotic patients are asymptomatic. ESLD – end stage liver disease is an indication for liver transplant with 5 year mortality of 50% of patient. Liver cirrhosis is the most common nonneoplastic cause of death among patients with hepatobiliary and GI diseases. Morphology : micronodular , macronodular ,mixed.

23. Macronodular cirrhosis

24. Micronodular cirrhosis

25. Causes of portal HTN are: Prehepatic  portal vein thrombosis. Hepatic  cirrhosis , HCC , fibrosis. Posthepatic  Budd- chiari syndrome. C irrhosis induced Portal HTN accounts for 90% of all Portal HTN cases. Rule of 2\3 of portal HTN: 2\3 of cirrhotic patient develop Portal HTN 2\3 of portal HTN patient develop Esophageal varices . 2\3 of esophageal varices are ruptured.

26. * Clinical presentation of liver cirrhosis : fatigue , anorexia, weight loss, jaundice, abdominal pain, peripheral edema, ascites, GI bleeding, and hepatic encephalopathy . *On physical examination  Spider angiomata and palmar erythema (alterations in sex hormone metabolism), Finger clubbing , leukonychia duputyren’s contracture. * Clinical presentation of cirrhosis with portal HTN : Esophageal varices , splenomegaly , caput medusa , hemorrhoids.

27. Ruptured Esophageal varcies is the most dangerous complication of Portal HTN. Ruptured esophageal acounts for 50% of upper GI bleeding in patients known to have esophageal varcies . Diagnostic test  EGD “ upper GI endoscopy” . * Treatment of ruptured Esophageal Varices : Large bore IV’s x 2 Iv fluids , Foleys catheter , cross blood send labs. Intubation to protect from aspiration.

28. Caput Medusa – Portal HTN

29. Example of palmar erythema- cirrhosis

30. Spider angioma

31. leukonychia - cirrhosis

32. Infections of the liver liver contains the largest portion of the reticuloendothelial system in the human body and is therefore able to handle the continuous low-level exposure to enteric bacteria that it receives through the portal venous system , nonviral infections are unusual .

33. Pyogenic Abscess Most common abscess seen in the U.S . 40%  Monomicrobial . 40%  Polymicrobial . 20%  Negative Culture. Commenst are Gram negative : E.coli (70%) , klibseila proteus . Most common liver abscess in the U.S . In patients with endocarditis and infected indwelling catheters, Staphylococcus and Streptococcus species are more commonly found . Treatment  include correction of the underlying cause and IV antibiotic therapy (8 weeks ).

34. Multiple hepatic Abscess. “ honeycomb appearance”

35. Amebic Abscess Entamoeba histolytica is a parasite that is endemic worldwide, infecting approximately 10% of the world’s population. ( areas with poor sanitaion ). Most commonly involve Rt superior anterior liver lobe . Most common type of liver abscess worldwide . Amebiasis should be considered in patients who have traveled to an endemic area and present with right upper quadrant pain, fever, hepatomegaly, and hepatic abscess . Leukocytosis is common, whereas elevated transaminase levels and jaundice are unusual

36. “Amebic - Anchovy paste abscess”

37. Ultrasound and CT scanning of the abdomen are both very sensitive but nonspecific for the detection of amebic abscesses. Metronidazole 750 mg three times a day for 7 to 10 days is the treatment of choice and is successful in 95% of cases. Aspiration of the abscess if : - large abscesses - not respond to medical therapy - superinfected . - abscesses of the left lobe of the liver at risk for rupture into the pericardium.

38. Hydatid Cyst Hydatid disease is due to infection by the tapeworm Echinococcus granulosus in its larval or cyst stage. 70 % of hydatid cysts found in the liver , others found in lung , brain or bone. Hydatid cysts commonly involve the right lobe of the liver, usually the anterior-inferior or posterior-inferior segments . Eosinophilia is seen in approximately 30% of infected patients. Ultrasonography and CT scanning of the abdomen are both quite sensitive for detecting hydatid cysts.

39. Ring like calcifications - Hydatid cyst

40. Unless the cysts are small or the patient is not a suitable candidate for surgical resection, the treatment of hydatid disease is surgically based because of the high risk of secondary infection and rupture . Medical treatment with albendazole relies on drug diffusion through the cyst membrane( albendazole preferred over mebendazole ) surgical resection involving laparoscopic or open complete cyst removal with instillation of a scolicidal agent is preferred and usually is curative . If complete cystectomy is not possible, then formal anatomic liver resection can be undertaken.

41. Benign Liver Lesions Hepatic Cyst Adenoma Hemangioma Focal nodular hyperplasia Bile duct Hamartoma

42. cyst 1. primary (congenital ) 2. secondary to trauma 3. infection ( pyogenic/ parasitic) 4. neoplastic disease. In most cases, congenital cysts are differentiated from secondary cysts (infectious or neoplastic origin) in that they have : well-defined thin wall , no solid component and are filled with homogeneous, clear fluid.

43. Simple hepatic cyst Vs Infectious hydatid cyst

44. Hemangioma Hemangiomas are the most common solid benign masses that occur in the liver . They consist of large endothelial-lined vascular spaces represent congenital vascular lesions that contain fibrous tissue and small blood vessels that eventually grow. surgical resection can be considered if the patient is symptomatic. Caution should be exercised in ordering a liver biopsy if the suspected diagnosis is hemangioma because of the risk of bleeding from the biopsy site . .

45. Liver H emangioma on CT

46. Adenoma Hepatic adenomas are benign solid neoplasms of the liver. They are most commonly seen in premenopausal women older than 30 years of age and are typically solitary. Use of Estrogen Contraceptives are clear risk factors. Histologically : Adenoma lacks bile duct glands , kupffer cells , have no lobules and contain hepatocytes that are congested. Hepatic adenomas also have a risk of malignant transformation to a well-differentiated HCC . Therefore, it usually is recommended that a hepatic adenoma (once diagnosed) be surgically resected.

47. Hepatic adenoma

48. Focal Nodular Hyperplasia FNH is a solid, benign lesion of the liver believed to be a hyperplastic response to an anomalous artery . Similar to adenomas, they are more common in women of childbearing age . Biphasic CT  well circumiscribed lesion with central scar . MRI  The lesion appear black on both T1 & T2 FNH lesions usually do not rupture spontaneously and have no significant risk of malignant transformation . Therefore, the management of FNH is usually reassurance and prospective observation irrespective of size . Oral contraceptive or estrogen use should be stopped when either FNH or adenoma is diagnosed. ( stop it )

49. Malignant liver tumor A – primary ( HCC , Cholangiocarcinoma ) B – Metastasis ( colorectal CA ) Most common liver tumor is Metastasis colorectal cancer . Around 150000 new cases of colorectal CA are diagnosed every year with 60% of them will have hepatic metastasis. TO be continued .