Liver surgical diseases

LIVER SURGICAL DISEASES

ANATOMY
The liver is the largest organ in the body : 1200-1600 g Regarded as a paired organ which is fused along a line which can be drawn between the gallbladder fossa and IVC. Each lobe receives a full branch of the portal vein, hepatic artery and bile duct. By further division of the vascular supply- each lobe is composed of 4 segments which are numbered 1 to 4 for the left and 5 to 8 for the right liver. Recognition of the segmental nature of the liver can be ascribed to the French surgeon, Couinaud.

ANATOMY

CLASSICAL ANATOMY
The classical description of the liver anatomy is based on the external appearance. On the diaphragmatic surface, the ligamentum falciforme divides the liver into the right and left anatomic lobes, which are very different from the functional right and left lobes In this classical description, the quadrate lobe belongs to the right lobe of the liver, but functionally it is part of left lobe.

Segmental anatomy according to Couinaud

Clockwise numbering of the segments

On a frontal view of the liver the posteriorly located segments 6 and 7 are not visible.

ANATOMY
Hepatic veins of surgical importance are three: the right hepatic vein which drains segments 6-8 by a short vessel directly into the suprahepatic vena cava, the middle hepatic vein which drains from both hepatic lobes and empties directly into the vena cava or the left hepatic vein the left hepatic vein which drains segment 2, 3, 4. Segment 1 or caudate lobe drains by several small hepatic veins directly into the infrahepatic vena cava.


PORTAL VEIN, CBD, CHA
In the portal hilum the portal vein which has formed behind the head of the pancreas by the junction of splenic and mesenteric veins, passes along the edge of the lesser omentum. In front of and to the right, common bile duct drains both liver lobes and receives the cystic duct at a variable point of its course and on either side. To the left of the common bile duct runs the common hepatic artery giving off the main cystic artery and branches to the common bile duct prior to division into right and left branches.

PORTAL SYSTEM

LIVER FUNCTION
1. Bile formation and excretion About 500-1000 ml. of bile are secreted each day. The liver synthesizes bile acids from cholesterol. Almost all of the bile acids are reabsorbed by the terminal ileum and enter the enterohepatic circulation. Bile pigments are derived from the breakdown of hemoglobin to biliverdin then bilirubin. In the liver unconjugated bilirubin is conjugated and then secreted into the bile canaliculi and transported to the gastrointestinal tract. Bile contains cholesterol in micellar form, bile acids, phospholipids, electrolytes, mucin and water.

JAUNDICE

Jaundice due to unconjugated bilirubinemia results from increased hemoglobin breakdown or diminished conjugation. Jaundice due to conjugated bilirubinemia is commonly associated with intrahepatic and extrahepatic bile duct obstruction and with hepatocyte damage.

JAUNDICE

LIVER FUNCTION
2. Protein metabolism The liver is a major sourse of beta and gamma-globulins and the only site of production of albumin and alpha-globulin. Hepatocytes are capable of protein synthesis from aminoacids. The liver is also the major site of urea synthesis. Most of coagulation factors are synthesized within the liver. 3. Carbohydrate metabolism

LIVER FUNCTION

LIVER FUNCTION


INVESTIGATIONS
1. Plain abdominal X-ray 2. Ultrasonography 3. CT scanning of the liver 4. Scintiscanning of the liver parenchyma 5. Portography and arteriography. 6. Needle biopsy of the liver

Plain abdominal X-ray

May give helpful information in terms of: liver size and the position of the overlying diaphragm. rarely a small gas/fluid level may be seen within an abscess hydatic cysts are well shown due to calcification within the cyst wall.

Ultrasonography

In patients with cholestasis, dilated IH-BD clearly pinpoint the presence of duct obstruction. Gallstones may be diagnosed with an accuracy of 95% in the best hands. Well shown are liver cysts and abscesses Primary liver tumours and multifocal MTS are readily seen. Intraoperative US of the liver can demonstrate precisely the anatomy of vascular structures, the boundaries of palpable liver tumours and the presence of impalpable foci enabling a more appropriate resection line.

CT scanning of the liver

Normally the procedure is combined with contrast meal to define the stomach and duodenum and iv contrast to outline the vessels and focal lesions within the liver. The procedure is expensive and time-consuming but it is consistent and leads to relatively easy interpretation. Furthermore surrounding structures are also well shown, particularly the diaphragm, lung bases and suprahepatic vena cava.

Big liver abscess and other three small liver abscesses

Chest X-ray with free air sickle and local drainage between diaphragm and liver

Scintiscanning of the liver parenchyma

Technetium scintiscann may detect focal lesions greater than 2 cm. in diameter in about two-thirds of cases. Generalized liver disease is demonstrated as reduced or patchy uptake with increased uptake of the spleen and bone marrow. Gallium citrate is concentrated in neoplastic foci and abscesses Hemangiomas concentrate isotope indium.


The use of 99mTc labelled red blood cells (RBC) for the diagnosis of suspected cavernous haemangioma in the liver. Note the discordant accumulation indicated by the arrow.

Portography and arteriography

Needle biopsy of the liver

Pyogenic abscesses

Aetiology Most pyogenic liver abscesses are secondary to infection originating in the abdomen. Cholangitis due to stones or strictures is the commonest cause, followed by abdominal infection due to diverticulitis or appendicitis. In 15% of cases no cause can be found (cryptogenic abscesses)

Microbiology

Most patients presenting with pyogenic liver abscesses have a polymicrobial infection usually with Gram egative aerobic and anaerobic organisms. Most organisms are of bowel origin, with Escherichia coli, Klebsiella pneumoniae, bacteroides, enterococci, anaerobic streptococci, and microaerophilic streptococci being most common. Staphylococci, haemolytic streptococci, and Streptococcus milleri are usually present if the primary infection is bacterial endocarditis or dental sepsis

Origins and causes of pyogenic liver abscess

x Biliary tract Gall stones Cholangiocarcinoma Strictures x Portal vein Appendicitis Diverticulitis Crohn's disease x Hepatic artery Dental infection Bacterial endocarditis
x Direct extension of: Gall bladder empyema Perforated peptic ulcer Subphrenic abscess x Trauma x Iatrogenic Liver biopsy Blocked biliary stent x Cryptogenic x Secondary infection of liver cyst

Clinical features of hepatic abscesses

Imaging investigations
Clinical suspicion of hepatic abscess may be confirmed by a technetium scintiscan or by ultrasonic or CT scanning of the liver which may also demonstrate the presence of pus. A plain film of the abdomen and chest may rarely show an air/fluid level within the liver substance and usually an elevated immobile diaphragm with loss of the anterior costophrenic angle is found.


Liver abscess

Treatment:

IV Antibiotics: Triple antibiotics with Metrinidazole Penicillin + Aminoglycoside + Metronidazole Cephalosporin + Metronidazole Percutaneous drainage with CT or U/S guidance
What are the indications for operative drainage ? Surgical drainage for: Multiple abscesses Loculated Abscesses If multiple percutaneous drainage failed

Amebic liver abscess is a collection of pus in the liver brought on by an intestinal parasite
Etiology:Entamoeba HistolyticaTypically reaches the liver via the portal vein from intestinal AmebiasisInfection & spread:Human are the only resevior of the infectionTransmission is Feco-Oral through the ingestion of the CystI.P. 1 – 3 Weeks (but can be from few days to several weeks)

Pathology:Ingestion of the cyst will lead to either: 90 %  Re-encysted  No Harm 10 %  Trophozoite emerge  HarmfulCecum is maximally affected The infection might be extra colonic after reaching the mesenteric vein  liver , lung , kidney , brain …. Troph. Emerge in the Small Intest
Troph. Migrate to colon where it multiply & invade the mucosa via their cytotoxic enzymes
Causing ulcerative post-dysenteric colitis
Classical flask shape ulcers or diffuse ulcers


Pathogenesis: Amoebic liver abscess develop when organisms invade through the bowel wall serosa Entering the Portal Vein and pass into the liver Multiple micro-abscesses develop which coalesce to form single or multiple large abscesses Usually it is single in the right lobe

Symptoms

Symptoms may include: Abdominal pain Particularly in the right, upper part of the abdomen Intense, continuous, or stabbing pain Chills Diarrhea Fever General discomfort or ill feeling (malaise) Jaundice Joint pain Loss of appetite Sweating Weight loss

Investigations:CBC : leucocytosisLFT : Abnormal “Elevated”Stool Analysis :At least 37 specimensCysts : usually found in formed stoolTroph.: liquid stoolSerology :Indiret haemagglutination test (ELISA) 95% +ve in extraintestinal , 85% +ve in intestinal+ve test suggest active disease since serology usually revert to –ve in 6 – 12 month


Investigations:Sigmoidoscopy :May show erosions Obtain biopsy will enhance the DxSigmoidoscopy & enema are potentially dangerous in acute Amebic colitis because of risk of perforationRadiology :CT scan & ultrasound are the best to show the Amebic liver abscessAspiration of the liver abscess:Yields fluid like “Anchovy Sauce”


Treatment of Amebic liver Abscess:Metronidazole 750 – 1000 mg orally or IV for 10 – 14 day ( 5-10 day)Diloxanide furoate or Iodoquinol Patient should also receive a course of luminal amebicide Diloxanide furoate 500 mg TID for 10 days Iodoquinol 650 mg TID for 20 daysNeedle aspiration of amebic liver abscess

Indications of Needle aspiration:Large abscess (>5cm) Threat of rupture “pointing sign”large left lobe abscess (risk to rupture into the pericardium)Lack of response to metronidazole treatment in 3-5 daysToxic or ill patientThe need to rule out of pyogenic abscess

Gross Pathology of amoebic liver abscess

Dysentery showing diffuse ulceration of mucosa

Ultrasound image of a large liver abscess in a child shows a typical hypoechoic collection within a rough/ shaggy walled cavity in the liver. It is likely that this lesion is due to amebic infection of the liver, a common condition in parts of India. As the disease progresses, sonography of the liver may reveal a fluid-debris layering and even later may cause an almost totally anechoic collection.

Complications of the liver abscess

recurrent septicemia extension and rupture of the abscess may occur in any direction: - peritoneal rupture results in peritonitis or subphrenic collection - extension through the diaphragm may lead to thoracic empyema or to a rupture into the bronchus with expectoration of large volumes of pus. - rarely, the abscess ruptures into the pericardium with high mortality.

Liver cysts

Most cysts are asymptomatic When the cysts reach sufficient size to exert pressure on adjacent viscera, produce non-specific symptoms of vomiting, upper abdominal pain. Clinical examination reveals a non-tender liver tumour. Plain film of the abdomen may show displacement of the colon or stomach The lesion may be confirmed by ultrasonography and scintiscanning.

Liver cysts

The main differential diagnosis is parasitic cysts and solid tumours. With exception of the complications of rupture and intracystic hemorrhage, the operative treatment is confined to large solitary cysts which are usually completely extirpated or removed by limited hepatic resection.


Hydatid cysts of the liver
This infestation is endemic in certain countries, particularly the southern half of South America, Australia, New Zeeland, France. Man is the secondary host and becomes infected by ingesting vegetables and water fouled by dogs or more directly by handling the parasite-infested dogs as pets. After ingestion the shell of the egg is destroyed by gastric acid and hatched within the duodenum. The liberated embryos migrate through the gut wall into the mesenteric circulation and lodge within the liver.

Echinococcus granulosus

Hydatic cyst of the liver
80% of hydatic cysts are ultimatelly found in the liver parenchyma.

The unilocular hydatic cyst is caused by Echinoccocus granulosus and the alveolar type is caused by Echinococcus multilocularis.

Clinical features

Since the growth of the parasite is slow, many years elapse before the cyst reaches significant size. On physical examination an anteriorly located cyst presents as a smooth rounded tense mass. Secondary infection results in tender hepatomegaly, rigors and pyrexia associated with a deep-seated continuous pain.

Further clinical features are the result of cyst complications

Intrabiliary rupture may give biliary colic and usually causes jaundice and fever. Intraperitoneal rupture produces severe pain and shock classically associated with pruritus and urticaria. Intrathoracic rupture may be preceded by symptoms of diaphragmatic irritation and rupture into bronchus leads to a partly bloodstained sputum which frequently becomes bile stained. Hydatic allergy is manifested by urticaria or very rare anaphylactic shock.

Investigations

The appearance of a painless liver swelling in a patient living in an endemic area gives a high index of suspicion. An unruptured cyst may show on plain radiograph as a calcified reticulated shadow if not calcified by displacement of the diaphragm or a barium-filled stomach. Scintiscanning shows a large filling defect and ultrasonography reveals an echogenic cyst. Although the cyst is isolated from the liver by an adventitial layer, there is an absorption of parasitic products which acts as an antigenic stimulus. This reflects in an eosinophilia in 25% of patients, a complement-fixation test which is accurate in 93% of patients.



Multivesicular Hydatid Hepatic Cyst

Univesicular uncomplicated cyst

Multivesicular hydatid with multiple daughter cysts giving a septated appearance to the cyst


Old hypermature liver hydatid. Non-contrast CT shows calcification in the cyst wall and matrix and fluid within the cyst


ComplicationsRupture. Three types of ruptures are possible: contained, communicating and direct.

Surgical treatment

Involves removing the cyst without contamining the patient. The initial stage involves protection of the operative field against live cysts using multiple coloured towels soaked in hypertonic saline which isolate the main cyst from the exposed peritoneal cavity. Since hydatid fluid is under high pressure the cyst is decompressed by aspiration and injected with 20% saline and left 5 min. after which the cyst is opened and all daughter cysts removed as well as the germinal layer of the cyst.

Surgical treatment

Spillage of cyst content during surgery is a cause of recurrence. The cavity is drained for a variable period of time depending on the presence of fluid drainage. Jaundice after intrabiliary rupture requires choledochotomy and clearance of cysts followed by T-tube drainage


Liver tumors
Incidental solid liver tumors: Diagnostic frequency for various histologies Tumor Relative frequency Hemangioma 52% Focal nodular hyperplasia 11% Metastatic tumor (TxNxM1) 11% Hepatocellular adenoma 8% Focal fatty infiltration 8% Hepatocellular carcinoma 6% Extrahepatic process 3% (e.g., abscess, adrenal tumor) Other benign hepatic process 1%

Hemangiomas 

Hemangiomas are the commonest benign tumour but only rarely produce symptoms. Histologically the lesion is composed of blood-filled endothelial lined spaces separated by a varible degree of fibrous tissue. These tumours, having grown to significant size will eventually produce pain or dyspepsia and develop a palpable abdominal mass. Rupture is rare but leads to a major intra-abdominal hemorrhage with shock and collapse.

Hemangiomas

CT scann is usually quite diagnostic. Where the diagnosis remains doubtful, arteriography will demonstrate the lesion. A biopsy is not indicated. The preferred treatment for clinically significant hemangiomas is wedge excision where possible. Lobectomy is reserved for large lesions confined to one lobe. The residual liver may contain further hemangiomas. Scintiscanning and angiography will demonstrate the lesion and if there appears to be a major feeding vessel from the hepatic artery, it may be worthwhile ligating this vessel or the main hepatic artery.

USS-hemangiomas

This is the commonest primary tumour of the liver and is usually a solitary lesion. This ultrasound image shows a hyperechoic, homogenous, well-circumscribed mass of the liver.

Liver cell adenoma Liver cell adenoma became more prevalent with the widespread use of oral contraceptives in the 1960s, but the reduced oestrogen content of modern contraceptives has made it less common. The risk of rupture is 10%, and malignant transformation is found in 10% of resected specimens. Patients should have liver resection to prevent these events.

Focal nodular hyperplasia not related to use of oral contraceptives usually asymptomatic Not premalignant Mass lesions usually contain a central stellate scar on computed tomography and magnetic resonance imaging. It does not require treatment unless symptomatic

Primary Hepatocellular carcinoma Intrahepatic Cholangiocarcinoma Hepatoblastoma Metastatic Colorectal Neuroendocrine Noncolorectal, Non-neuroendocrine

Primary malignant tumours of the liver

Physical findings:

- abdominal distension due to hepatomegaly - ascites and sometimes is blood-stained. - hypoglycemia - hypercalcemia, - hyperlipidemia - hyperthyroidism

Diagnosis

Tumour localization and evaluation
Lesions greater than 2 cm. in size can be detected as a filling defect on a hepatic scintiscan but this mode of investigation has little value. Ultrasound scanning demonstrates the size and position. CXR for pulmonary metastases. CT scan demonstrates the lesion and its relatioship to major structures. Needle biopsy under CT guidance. Arteriography is indicated for those patients in whom liver resection is contempleted.

Surgical treatment