| How is liver anatomy? | The liver is one of the largest organs in the body, representing up to 2% of the total body weight.(1.5 Kg).
Variety of functions
Ligaments: Coronary ligament: Peritoneal reflection on the cranial aspect of the liver that attaches it to the diaphragm.
Triangular ligaments:
The right and left lateral extensions of the coronary ligament
Falciform ligament: Connects the anterior abdominal wall to the liver; contains the ligamentum teres (obliterated umbilical vein).
Glisson’s capsule:
The peritoneal membrane that covers the liver. |
| How is liver blood supply? | Venous drainage:
The left, middle, and right hepatic veins drain into the inferior vena cava (IVC).
The portal vein is formed by the confluence of the splenic and superior mesenteric veins at the level of the second lumbar vertebra behind the head of the pancreas, 6-9 cm to the hilum
3 major hepatic veins: left, right, and middle.
The right hepatic vein drains into the vena cava independently
the middle and left hepatic veins join outside the liver, forming a common trunk |
| How is arterial blood supply? | The hepatic artery supplies approximately 25% of the 1500 mL of blood that enters the liver each minute; the remaining 75% is supplied by the portal vein
Celiac trunk ,left gastric, splenic, and common hepatic arteries.
Common hepatic artery divides into the proper hepatic artery and the gastroduodenal artery.
Proper hepatic artery divides into the right and left hepatic arteries
Variations of the standard arterial anatomy of the liver are relatively common, seen in up to 40% of patients
Recognition of this anatomical variant is critical during surgery of the liver and on the extrahepatic biliary tree |
| How is liver biliary drainage? | The right anterior and right posterior sectoral ducts unite to form the main right hepatic duct,
The union of ducts draining segments II, III, and IV forms the
left hepatic duct.
The left hepatic duct typically is longer and has a longer extrahepatic course than the right hepatic duct.
Drainage of segment I (caudate lobe) is principally into the left hepatic duct
Anatomic variations in the biliary ductal anatomy : 30% of patients
Recognition of this variation is crucial for the surgeon performing a left hepatectomy for avoiding injury of the right posterior biliary drainage.
Variations are far less common on the left side |
| How is segmental anatomy of liver? | Couinaud’s liver segments (I through VIII) numbered in a clockwise manner.
The left lobe includes segments II to IV,
The right lobe includes segments V to VIII,
The caudate lobe is segment |
| How is liver physiology? | Total hepatic blood flow (about 1500 mL/min; 30 mL/min per kg body weight) constitutes 25% of the cardiac output,
2/3 of the flow enters through the portal vein
1/3 through the hepatic artery.
Pressure in the portal vein is normally low (10-15 cm H2O
[7-11 mm Hg]).
The liver derives half of its oxygen from hepatic arterial blood and half from portal venous blood
Hepatic arterial flow increases or decreases reciprocally with changes in portal flow; sudden occlusion of the portal vein results in an immediate 60% rise in hepatic arterial flow.
Portal venous flow does not increase with reductions in arterial flow; sudden reductions in hepatic arterial supply are not immediately met by significant increases in portal vein flow.
It is for this reason that interruption of hepatic arterial
flow to the right or left liver generally has little impact on hepatic function. |
| What is use of portal embolisation? | in patients undergoing hepatic arterial embolization of liver tumors occlusion of the right or left portal venous branches results in profound ipsilateral hepatic atrophy and contralateral hypertrophy
Intentional occlusion of a major portal vein branch (usually the right side) is a procedure being used with greater frequency prior to major hepatic resection
->Atrophy of the liver to be resected,
Hypertrophy of the future liver remnant,
The risk of postoperative hepatic failure may be reduced |
| What is hepatic resection? | Removal of 70 of the normal liver can be performed with the expectation that the liver remnant will regenerate sufficiently for the patient to survive.
only in patients with normal hepatic function
regenerative capacity of the liver rapidly provides new functioning hepatocytes.
Within 24 hours after partial hepatectomy, cell replication becomes active and continues until the original volume of hepatic tissue is restored.
the process is essentially complete by 4-5 weeks |
| How is preop evaluation of hepatic resection? | functional status of the liver/ Cirrhosis ,chemotherapy
Child–Pugh scoring
The indocyanine green clearance test system.
Cirrhosis is a relative contraindication
for partial hepatectomy because the limited reserve of
the residual cirrhotic liver may be insufficient to meet essential metabolic demands, and the cirrhotic liver has a reduced capacity for regeneration |
| What are classes of hepatic resection? What is the extent? | Hepatic resections are classified as :
Anatomical (based on the segmental liver anatomy) .
Nonanatomical (Wedge resections,enucleations, and resectional debridement of devitalized tissue)
Anatomical resections are preferred because:
lower blood loss.
lower incidence of positive resection margins (malignancy).
Major resections must be performed in accordance with the segmental anatomy.
The operation entails removal of a lobe or segment with its afferent and efferent vessels while avoiding injury to vessels and bile ducts supplying the remnant tissue. |
| What are complications of hepatic resection? | >40% of patients after major liver resection (≥ 3 segments)
perihepatic fluid collections requiring drainage , 10%-15% of patients.
Post operative bleeding, 10 -15%
Relative hepatic insufficiency (hyperbilirubinemia, ascites, coagulopathy) is common but resolves in most patients as the liver regenerates
Pulmonary complications. The most common are symptomatic pleural effusions or atelectasis; pneumonia is infrequent.
Mortality rates are low, 1%-3% in specialized centers |
| What are indications for hepatic resection? | Liver resection is most commonly indicated for
Primary and secondary malignant tumors
Symptomatic benign tumors.
less common indications include
Traumatic injury.
Infection/abscesses
Living donor transplantation. |
| What are hepatic abscesses? | A collection of pus in the liver of bacterial, fungal, or parasitic origin that
Most commonly involves the right lobe.
The two main subtypes are :
Pyogenic (bacterial) Most hepatic abscesses (80%)
Amebic.
RISK FACTORS
Pyogenic: Usually secondary to bacterial sepsis or biliary or portal vein infection.
Can also occur from a perforated infected gallbladder, cholangitis, diverticulitis, liver cancer, or liver metastases.
Amebic: Patients from Central America, homosexual men, institutionalized patients, and alcoholics. |
| What are types of hepatic abscesses? | Pyogenic abscesses : the most common organisms isolated from are Escherichia coli, Klebsiella,and Proteus.
Amebic abscesses are classically described as “anchovy paste” in appearance and are caused by Entamoeba histolytica, which gains access to the liver via the portal vein from intestinal amebiasis. |
| What are S&S and dx of hepatic abscesses? | SIGNS AND SYMPTOMS
Fever, chills, RUQ pain, jaundice, sepsis, and weight loss
Amebic abscesses tend to have a more protracted course.
DIAGNOSIS
Leukocytosis
Elevated liver function tests (LFTs)
Ultrasound or computed tomography (CT) of the liver
Serology for amebic abscesses. |
| How is tx of hepatic abscesses? | Pyogenic: Ultrasound or CT-guided percutaneous drainage with IV antibiotics;
operative drainage indicated if percutaneous attempts fail or cysts are multiple or loculated.
Amebic: Operative drainage not indicated unless abscesses do not resolve with IV metronidazole or are superinfected with bacteria.
PROGNOSIS
Mortality is low for uncomplicated abscesses, but complicated abscesses carry a 40% mortality risk |
| What are hepatic cysts? Hydatid | Hydatid Cyst
DEFINITION
A hepatic cyst caused by Echinococcus multilocularis or Echinococcus granulosus that is usually solitary and involves the right lobe of the liver.
RISK FACTORS
Exposure to dogs, sheep, foxes, wolves, domestic cats, or foreign travel.
SIGNS AND SYMPTOMS
Most commonly asymptomatic; can cause hepatomegaly.
DIAGNOSIS
Often picked up incidentally on ultrasound, CT, or abdominal films, which may show calcifications outlining the cyst; eosinophilia, serology.
TREATMENT
Never aspirate these cysts or they will spill their contents. Treat with albendazole or mebendazole followed by surgical excision or unroofing. |
| What are non-parasitic hepatic cysts? | DEFINITION
Benign cysts within the liver parenchyma that most commonly involve the right lobe; are thought to be of congenital origin.
INCIDENCE
Rare; 4:1 female:male ratio.
SIGNS AND SYMPTOMS
Most cysts are small and asymptomatic; large cysts (rare) can present with increasing abdominal pain and girth and can bleed or become infected.
DIAGNOSIS
Hypointense or water density on ultrasound, CT, or MRI with no septations.
TREATMENT
Small asymptomatic cysts require no treatment.
large, symptomatic cysts should be surgically excised |
| What is cavernous hemagioma? | DEFINITION
A benign vascular tumor resulting from abnormal differentiation of angioblastic tissue during fetal life; usually located in the right posterior segment of the liver.
INCIDENCE
Most common benign tumor of the liver; occurs at all ages.
SIGNS AND SYMPTOMS
Usually asymptomatic; rarely presents with pain, a mass, or hepatomegaly.
DIAGNOSIS
Usually discovered incidentally.
Early peripheral enhancement with intravenous (IV) contrast on CT, MRI, or tagged red cell scan
Do not biopsy, as hemorrhage can occur.
TREATMENT
Surgical resection if symptomatic or in danger of rupture; otherwise, observe. |
| What is hamartoma? | DEFINITION
A benign focal lesion of the liver that consists of normal tissue that has differentiated in an abnormal fashion; are multiple subtypes, depending on the types of cells involved (e.g., bile duct hamartoma, mesenchymal hamartoma, etc.).
INCIDENCE
Very Rare.
SIGNS AND SYMPTOMS
Typically asymptomatic; can present with RUQ pain or fullness.
DIAGNOSIS
Usually discovered incidentally during radiologic imaging; may require histopathologic evaluation.
TREATMENT
Surgical excision |
| What is adenoma? | DEFINITION
A mass lesion of the liver characterized by a benign proliferation of hepatocytes.
INCIDENCE
Most common in premenopausal females with a multiyear history of oral contraceptive (OCP) use.
RISK FACTORS
OCP use, long-term anabolic steroid therapy
SIGNS AND SYMPTOMS
Abdominal pain , Abdominal mass Bleeding . Can also be asymptomatic
DIAGNOSIS
Homogeneous and hyperintense on T1- or T2(MRI) or CT, but 10–20% have hemorrhagic areas, making appearance heterogeneous. Biopsy/US or CT
TREATMENT
Cessation of OCPs
Surgical excision |
| What is focal nodular hyperplasia? | DEFINITION
A benign hepatic tumor thought to arise from hepatocytes and bile ducts that has a characteristic “central scar” on pathologic evaluation.
INCIDENCE
Most common in premenopausal females.
SIGNS AND SYMPTOMS
Usually asymptomatic; 10% of patients present with abdominal pain and/or a RUQ mass.
DIAGNOSIS
Usually incidental on ultrasound or CT; can be differentiated from hepatocellular adenoma by a Tc-99 study. Biopsy/US or CT
TREATMENT
Resect if patient is symptomatic. |
| What is hepatocellular carcinoma? | DEFINITION
A malignant tumor derived from hepatocytes frequently found in association with chronic liver disease, particularly cirrhosis.
INCIDENCE
Accounts for 80% of liver cancers, but < 2% of all cancers.
Much more common in males (3:1)
Usually diagnosed in the fifth or sixth decade.
Greatest incidence in Asia and Africa |
| What are risk factors of hepatocellular carcinoma? | Hepatitis B
Hepatitis C
Cirrhosis
Aflatoxins (found in peanuts)
Liver flukes
Hemochromatosis
Alpha-1-antitrypsin deficiency
Anabolic steroid use |
| What are S&S of hepatocellular carcinoma? | SIGNS AND SYMPTOMS
Weight loss
Weakness
Dull pain in the RUQ or epigastrium
Nausea, vomiting
Jaundice
Nontender hepatomegaly
Splenomegaly (33%)
Ascites (50%) |
| How is dx of hepatocellular carcinoma? | CT with IV portography often shows hypervascular tumor, frequently with multicentric disease.
Ultrasound shows hyperechoic tumor.
Combination of CT, ultrasound, and MRI is 80% sensitive.
CT or ultrasound-guided needle biopsy will give the definitive diagnosis.
Tumor marker: serum alpha-fetoprotein
Metastases most common to hilar and celiac nodes.
Differential Diagnosis
Metastatic hepatic carcinoma
Cholangiocarcinoma
Benign neoplasm
Other abdominal malignancy |
| How is tx of hepatocellular carcinoma? | Surgical resection is the only cure, consisting of either lobectomy or segmental resection with at least 0.5 cm margins (25% are candidates)
Liver transplantation is treatment of choice in the presence of cirrhosis.(<3T <3cm or 1T <5cm)
Contraindications: medical comorbidity, total tumor volume >6.5 cm (for liver transplantation)
Ablative procedures: ethyl alcohol ablation (75% complete necrosis),radiofrequency ablation
PROGNOSIS
Most patients die within the first 4 months if the tumor is not resected.
After resection or transplant, the 5-year survival is approximately 25%. |
| What are metastatic neoplasms of liver? | The most common hepatic malignancy is metastases.
The primary is usually from colon, breast, or lung, with bronchogenic carcinoma being the most common primary cancer.
20% of patients with metastatic colon cancer have metastasis to the liver.
SIGNS AND SYMPTOMS
Patients are usually asymptomatic until the disease has become advanced and the liver begins to fail.
Weight loss, fatigue, fevers, right upper quadrant pain. |
| How is dx and tx of metastatic neoplasms of liver? | DIAGNOSIS
Increased ALP, GGT, lactic dehydrogenase (LDH), AST, and ALT (nonspecific).
Metastases will enhance on contrast CT .
Intraoperative ultrasound with liver palpation is the most sensitive diagnostic tool
TREATMENT
Surgical resection (metastasecomy or hepatectomy)
Most common resectable tumors are colon, endocrine, melanoma.
Contraindications to surgery: extrahepatic disease
Prognosis: colon cancer has 45% 5-year survival with radical resection. We have to be aggressive in the indication and resection
Hepatic artery chemotherapy (metastatic colon cancer only).
Radiofrequency ablation or cryotherapy for unresectable lesions if all can be addressed and extrahepatic disease is absent.
Monitor treatment with carcinoembryonic antigen (CEA)levels for colon cancer; CT scanning.
Prognosis: colon cancer has 45% 5-year survival with radical resection. |
| What are uncommon primary hepatic tumors? | Tumors include
Angiosarcoma.
Hepatoblastoma.
Hepatic adenocarcinoma.
Intrahepatic cholangiocarcinoma.
Symptoms and signs include right upper quadrant pain, weight loss, hepatomegaly.
CT scan shows hypervascular tumor for angiosarcoma; multiseptate cyst for adenocarcinoma.
Workup:
perform CT scan followed by Tumor biopsy or resection for diagnosis and treatment
DIFFERENTIAL DIAGNOSIS:
Hepatocellular carcinoma.
Metastatic carcinoma.
Benign neoplasm.
Other abdominal malignancy. |
| How is tx of hepatic uncommon primary tumors? | TREATMENT
Surgical resection for localized tumor.
Contraindications: poor liver function, extrahepatic disease, diffuse hepatic disease.
Medications: chemotherapy for unresectable lesions.
PROGNOSIS
resectable cholangiocarcinoma has 5-year survival of 15–20%; angiosarcoma has very poor prognosis; hepatoblastoma has overall survival of 50%. |
| what is portal HTA? | DEFINITION
Portal pressure > 10 mm Hg (measure with indirect hepatic vein wedge pressure).
CAUSES
Prehepatic: Congenital atresia, cyanosis, or portal vein thrombosis.
Intrahepatic: Cirrhosis, hepatic fibrosis from hemochromatosis, Wilson’s disease, or congenital fibrosis.
Posthepatic: Budd–Chiari syndrome (thrombosis of the hepatic veins), hypercoagulable state, lymphoreticular malignancy |
| What are S&S of portal HTA? | SIGNS AND SYMPTOMS
Jaundice.
Hematemesis, Melena (Bleeding gastroesophageal varices)
Splenomegaly.
Palmar erythema.
Spider angiomata.
Ascites.
Asterixis (a flapping hand tremor).
Hepatic encephalopathy.
If >12mmhg ->variceal bleed, if >15 mmHg -> brisk bleeding, if >20mmHg ->continuous bleed |
| What are portosystemic collateral and their clinical manifestations? | Left gastric vein to the esophageal veins—esophageal varices
Umbilical vein (via the falciform ligament) to the epigastric veins— caput medusa
Superior hemorrhoidal vein to the middle and inferior hemorrhoidal veins—hemorrhoids
Veins of Retzius (posterior abdominal wall veins) to the retroperitoneal lumbar veins—retroperitoneal varices |
| What is the rule of 2/3 of portal HTA? | Rule of two thirds for portal hypertension:
Two thirds of patients with cirrhosis develop portal hypertension.
Two thirds of patients with portal hypertension develop esophageal varices.
Two thirds of patients with esophageal varices will bleed from them |
| How is dx of portal HTA? tx? | Suggestive history and physical examination.
Doppler ultrasound: Initial procedure of choice
Ultrasound shows dilated portal vein, thrombosis of portal vein or hepatic veins, hepatoma .
CT scan, MRI shows dilated venous collaterals, venous thrombosis, cirrhotic liver.
Esophagogastroscopy for diagnosis of varices.
Liver Biopsy may be required to confirm cirrhosis
Tx:
Sclerotherapy or banding of varices (by esophagogastroscopy).
TIPS, Sengstaken-Blakemore tube placement, blood products as necessary.
Medications: β-blockers, nitrates, vasopressin (during bleeding), octreotide (during bleeding) |
| What is transjugular intrahepatic portosystemic shunt? | During the TIPS procedure, a radiologist makes a tunnel through the liver with a needle, connecting the portal vein to one of the hepatic veins. A metal stent is placed in this tunnel to keep the tunnel open.
Complication: Shunt narrowing or occlusion (blockage)
Follow-up ultrasound examinations
The signs of occlusion include increased ascites or recurrent bleeding.
This condition can be treated by a radiologist who re-expands the shunt with a balloon or repeats the procedure to place a new stent.
Encephalopathy, can be worse when blood flow to the liver is reduced by TIPS, which may result in toxic substances reaching the brain without being metabolized first by the liver |
| What are surgical tx of portal HTA? | Surgical portosystemic shunt (total vs partial vs selective)
Surgical shunt is indicated for Childs A failed endoscopic therapy, elective (selective) or emergent (partial).
Liver transplantation is indicated for Childs C if donor is available, no medical comorbidity, not currently drinking alcohol |
| What are types of shunts? | Total (END to SIDE Control bleeding Encephalopathy, SIDE to SIDE >10mm Control bleeding and ascitis)
Partial (side to side diam 8mm90% control of bleeding Graft 2-3 cm)
Selective (Distal Splenorenal Shunt 90% control of bleeding 15% encephalopathy) |
