OPEN ACCESS TEXTBOOK OF GENERAL

SURGICAL DISEASES OF THE JEJ Krige S Burmeister

supply. This system of eight INTRODUCTION structurally and functionally independent liver segments has now Surgery of the liver and portal been universally adopted (Figure 2). circulation is based on a clear

understanding of the detailed anatomy of the liver, its arterial and portal blood supply, as well as the biliary and venous drainage.

ANATOMY The liver is the largest abdominal organ, weighing approximately 1500g and extends from the fifth intercostal space to the right costal margin. It is wedge shaped, its apex reaching the left midclavicular line in the fifth intercostal space. The liver is attached to the undersurface of the diaphragm by suspensory ligaments which enclose a “bare area”, the only Figure 2: Schematic diagram of the part of its surface without a peritoneal segmental anatomy of the liver. Each covering. segment receives its own portal Topographically the liver is divided by pedicle (triad of portal vein, hepatic the attachment of the falciform artery, and ). ligament into right and left lobes; The right liver has four segments (5, 6, fissures on its visceral surface 7, 8) and the left liver three (2, 3, 4). demarcate two further lobes, the The caudate lobe, which has a quadrate and caudate. (Fig 1) separate venous drainage to the inferior vena cava, constitutes segment 1. Each segment contributes hepatic veins that join to form the three main veins; the right hepatic drains segments 5-8, the middle hepatic drains from both (segments 4 and 5); and the left hepatic drains segments 2-4 (Figure 3).

Figure 1: Liver Anatomy The obvious surface markings of the liver which divide it into the anatomical right and left lobes conceal a functional system of liver segments divided vertically by the scissurae demarcated by the planes of the right, middle and left hepatic veins. Within each of the resulting four liver sectors there is a segmental arrangement Figure 3: Segmental anatomy of the defined by the portal and arterial blood liver.

Major resections of the liver are possible provided whole segments with their associated blood supply, biliary and venous drainage are left intact. Identification of segmental anatomy is mandatory in patients with focal lesions being considered for surgery, as this aids planning of liver resections. Accurate localisation of individual lesions by preoperative imaging and intraoperative ultrasound may allow segmental anatomic resections that Figure 4: Portal Venous Anatomy reduce blood loss and loss of hepatic functional reserve. A theoretical plane, the main portal fissure, separates the two lobes. The right portal vein, the shorter of the two, Blood Supply lies anterior to the caudate process The liver normally receives 1500 mL of and enters the liver through the hilar blood per minute and has a dual blood plate to divide into anterior and supply: 65% comes from the portal posterior branches. The anterior vein and 35% from the hepatic artery. branch divides into segments VIII and Because of its better oxygenation the V. The posterior branch supplies hepatic artery supplies 50% of the segments VII and VI. The left portal oxygen requirements. vein is longer than the right and runs transversely in the hilum and then The venous drainage of the liver superiorly in the base of the umbilical comprises three main hepatic veins fissure to supply segments II, III, IV that drain into the suprahepatic inferior and the caudate lobe. The anatomy of vena cava, and smaller accessory the left portal venous system is hepatic veins that drain into the remarkably constant. retrohepatic vena cava. The right hepatic vein is single in 90 per cent of The common hepatic artery, usually a cases. The middle hepatic vein runs branch of the coeliac trunk but in the principal portal fissure and forms occasionally of the superior a common trunk with the left hepatic mesenteric artery, supplies the liver vein in 85 per cent of cases. The left with arterial blood through its right and hepatic vein arises from the left hepatic branches. The right confluence of a transverse vein which hepatic artery passes behind the drains segment II, and a sagittal vein common bile duct and right hepatic which drains segment III and has duct to enter the liver parenchyma. contributions from segment IV. The left hepatic artery runs along the inferior margin of the quadrate lobe, The portal vein divides at the hepatic with the left hepatic duct and left portal hilum into right and left pedicles on vein before entering the left lobe in the which the right and the left lobes of the umbilical fissure (Figure 5). liver respectively are based (Figure 4).

bilirubinaemia is caused by an overproduction of bilirubin, usually as a result of haemolytic diseases such as congenital spherocytosis. It may also be caused by decreased hepatocyte uptake in sepsis or decreased conjugation caused by drug reactions, jaundice of prematurity, cirrhosis, hepatitis or Gilbert’s syndrome. An increase in conjugated Figure 5: Hepatic Arterial Supply bilirubin may be the result of decreased secretion caused by drug LIVER PHYSIOLOGY reactions, cirrhosis, hepatitis, cholestasis of pregnancy or Dubin– The liver has a key role in a wide Johnson syndrome, but more often is spectrum of complex and critical the result of biliary obstruction. functions. These include metabolism Excess conjugated bilirubin in the of carbohydrates, lipids, proteins and urine resulting from extra- or vitamins, production of bile, intrahepatic biliary obstruction, detoxification of both exogenous and produces the dark urine and pale stool endogenous blood-borne substances, of obstructive jaundice. In contrast, and immune function via the fixed excessive urobilinogen in the urine reticuloendothelial system of Kupffer implies an increased load or failure of cells. There is no single extraction. comprehensive test of ‘liver function’ and the term ‘liver function tests’ An increase in serum alkaline (‘LFTs’) covers a wide variety of phosphatase in hepatobiliary disease investigations used for different is a sensitive marker of biliary purposes. The most commonly obstruction and is also elevated in performed blood tests include the patients with space-occupying lesions serum bilirubin which is a measure of in the liver. γ GT activity is induced conjugation and excretion of bile by a variety of drugs, including pigment, alkaline phosphatase, an ethanol, and may be markedly enzyme associated with cholestasis elevated even after a single episode of and the transaminases, alanine excessive alcohol intake. In aminotransferase (ALT) and aspartate combination with raised transaminase aminotransferase (AST), which are levels and increased mean elevated by liver cell injury. γ-glutamyl corpuscular volume (MCV), it is a transpeptidase (or γ-glutamyl sensitive though non-specific indicator transferase, GGT) provides a sensitive of chronic alcohol abuse. 5’- measure of enzyme induction, nucleotidase is less commonly used, including that associated with alcohol but is more specific than alkaline abuse. Albumin concentration is a phosphatase in detecting liver disease. measure of hepatocellular protein Some elevation of AST and ALT is synthesis, as is the prothrombin time. found in almost all forms of liver These basic tests give a broad disease. Both are significantly assessment of underlying liver elevated in the presence of hepatocyte pathology, and are considered in more necrosis, though there is no direct detail below. relationship with the degree of Jaundice becomes clinically apparent functional liver impairment. High when plasma bilirubin exceeds values are found in acute hepatitis, but 50mmol/l, which is three times the high levels without a raised alkaline upper limit of normal. Routine bilirubin phosphatase suggest a hepatocellular levels reflect total bilirubin, but in some rather than an obstructive cause for circumstances it is useful to measure jaundice. conjugated and unconjugated bilirubin separately. Unconjugated hyper- Albumin is one of the most important capacity and serum ferritin are used in plasma proteins produced by the liver. the diagnosis of haemochromatosis. Patients with cirrhosis and ascites Caeruloplasmin and urinary copper frequently have low plasma albumin levels are used to diagnose Wilson’s levels. Albumin levels are affected not disease. a1-antitrypsin is measured only by liver disease but also by when a deficiency of this enzyme is nutrition, osmotic pressure, acute suspected. Specific markers for phase reaction stimuli and alcohol. neoplasms include alpha-fetoprotein Thus the serum albumin concentration (AFP) and carcinoembryonic antigen per se is not an accurate prognostic (CEA) levels. Infectious serologic indicator in liver disease although it is markers include cytomegalovirus a useful component of the Child-Pugh (CMV), Epstein-Barr virus antibodies, scoring system. leptospiral agglutination tests and amoebic and hydatid complement The liver is the major synthetic site for fixation tests. all coagulation proteins except von Willebrand’s factor. The synthesis of Scoring systems in liver disease factors II, VII, VIII and X is dependent on normal liver function and on Scoring systems have been used to adequate vitamin K levels. As vitamin monitor the progression of conditions K is fat soluble, deficiency develops in such as primary biliary cirrhosis and the presence of biliary obstruction with sclerosing cholangitis, and to predict fat malabsorption. The prothrombin the need and timing of transplantation. time must always be checked before The most commonly used is the invasive procedures are undertaken in Child’s grading system, modified by patients with suspected liver disease. Pugh. Originally designed to predict Parenteral administration of vitamin K mortality and encephalopathy following usually corrects deficiencies caused portal-systemic shunting, the Child- by biliary obstruction, but is not Pugh classification has been extended effective in patients with prolonged or to grade liver function and assess risk severe hepatocellular disease in whom in patients with liver disease. A new fresh frozen plasma or cryoprecipitate system is the Model for End-stage should be given. Liver disease (MELD) which measures The above tests are static indicators of 3 factors, bilirubin, INR and creatinine. individual components of liver function. More sensitive information may be DIAGNOSIS OF LIVER DISEASE obtained by quantitative or semi- The clinical history, physical quantitative dynamic tests, including examination, urine investigation and antipyrine, aminopyrine, lignocaine stool and haematology tests are and galactose clearance tests. Arterial important and combined with the liver ammonia levels are sometimes biochemical tests and radiographic measured in patients with suspected examinations allow an initial liver failure and portal systemic differential diagnosis and direct triage encephalopathy. The indocyanine and supplementary investigations. green dye clearance test is used in some specialist units to predict Details of any anorexia, nausea, complications after hepatic resection jaundice, pruritus, fever and pain, as and rejection after . well as previous operations, drugs (especially alcohol), toxins and Other tests used in liver disease exposure to infection should be sought. Fever and pain are common Specific tests for liver disease include in alcoholic hepatitis; rigors and screening for hepatitis A, B and C. sudden severe pain suggest Antimitochondrial, smooth muscle and cholangitis. Relentless progression of antinuclear antibodies are used to jaundice with weight loss, pruritus and investigate suspected primary biliary pale stools point to malignant cirrhosis and autoimmune chronic extrahepatic obstruction. Prior biliary active hepatitis. Iron, iron-binding surgery directs attention to the bile duct. Transfusion, injections, quick, cheap and patient-friendly and polypharmacy, promiscuity, contact can be used to guide invasive with dialysis patients or jaundiced procedures such as drainage of fluid persons, intravenous drug use and collections and biopsies. Intrahepatic tattooing raise the possibility of duct dilatation is usually indicative of hepatitis. biliary obstruction and US establishes the presence and level of biliary Stigmata of chronic liver disease obstruction in over 90% of cases, including palmar erythema, spider similar to computed tomography naevi, finger clubbing, white nails, scans. Parenchymal liver disease or gynaecomastia, muscle wasting, sclerosing cholangitis may prevent spontaneous bruising and scratch- biliary dilatation and obesity and bowel marks from pruritus should be gas can limit visibility. Use in ICU and specifically excluded. Skin bruising theatre (including laparoscopic) may be present, reflecting the clotting extends its role. Duplex doppler defects characteristic of vitamin K combines US and doppler to evaluate deficiency in severe liver disease. blood flow in vessels, tumours and Testicular atrophy, gynaecomastia, shunts. parotid enlargement and Dupuytren’s contracture suggest an alcoholic Computed tomography (CT) aetiology. Intellectual deterioration, flapping tremor and foetor hepaticus scanning indicate marked liver decompensation. CT scanning is extremely helpful in Liver size, consistency and tenderness evaluating liver disease and masses, should be noted. Greater enlargement often complementing ultrasound. tends to occur with extrahepatic biliary Spiral CT allows the rapid acquisition obstruction. Jaundice and a palpable of high quality images during various suggest periampullary intravenous contrast phases. Lipiodol, cancer (Courvoisier’s law). A cirrhotic an iodized oil suspension, has some liver may be large, medium-sized or value in detecting small primary small with blunt, lobulated and firm hepatocellular carcinomas. edges. A liver with hepatocellular cancer is often large, hard and Magnetic resonance imaging nodular. A systolic bruit over the liver may indicate hepatocellular cancer or Magnetic resonance imaging (MRI) alcoholic hepatitis. Dilated abdominal images hydrogen nuclei in water using wall veins draining away from the magnetic fields and radiowaves. umbilicus signify . Different sequences may provide Splenomegaly and ascites should be valuable information for the surgeon in noted. evaluating the nature of liver tumours.

IMAGING Biliary imaging Endoscopic retrograde X-rays cholangiopancreatography (ERCP) Liver size may be indicated by bowel and percutaneous transhepatic displacement. Calcification in (PTC) can both be gallstones (10-15%) and chronic used to depict biliary strictures, pancreatitis or mass effects of tumours or calculi. tumours, or hydatid cysts can sometimes be seen. Gas in Hepatic angiography intrahepatic bile ducts or abscess Hepatic angiography is particularly cavities can aid in diagnosis. useful prior to liver resection to detect arterial anomalies. Arterial portography Ultrasound with Digital Subtraction Angiography Ultrasound (US) is the first line (DSA) is used in patients with portal radiological test used for hepatobiliary hypertension. disease, especially jaundice. US is Arterial embolization fibrolamellar liver tumours often do not express AFP, but the presence of Selective transcatheter arterial embolic neurotensin and elevated vitamin B12- occlusion with a variety of materials binding capacity in the serum are including metal coils and gelfoam relatively specific for this type of allows treatment of arterial injuries. tumour. Rapid recourse to Shrinkage of tumours by occlusion or percutaneous biopsy of a liver mass chemo-embolisation of the arterial without careful diagnostic evaluation blood supply is used in selected and planning of possible treatment is cases. Transhepatic portal venous often inappropriate, may be dangerous embolization is used to produce and is often not necessary. atrophy of a liver lobe and allow hypertrophy of the remaining liver Imaging before resection. Radiological imaging is the Isotope scanning cornerstone of diagnosis for focal liver lesions. Various algorithmic Nuclear medicine studies may be of approaches have been described, all value in diagnosing certain liver starting with an ultrasound scan. The masses, the causes of postoperative initial questions to determine are jaundice, and in evaluating the whether lesion(s) are single or success of biliary drainage multiple, or solid or cystic. Cystic procedures. Positron emission lesions of the liver are considered later tomography (PET scanning) is a new in this chapter. The solitary or investigation which may enable better potentially resectable liver ‘tumour’ is detection of hepatic primary and best evaluated by CT and, when secondary tumors, due to increased appropriate, MRI scanning. Each of glucose metabolism in neoplasms. the benign and malignant tumour types has typical but seldom ASSESSMENT OF A LIVER MASS diagnostic appearances. The CT This common problem merits separate evaluation of the tumour appearance consideration. The objectives in and behaviour during the various assessing a liver mass are: phases of contrast injection may be helpful. It should be possible to · to establish a diagnosis distinguish most cavernous · to determine whether surgery is haemangiomas from other tumours by indicated this means, though some vascular tumours may create difficulty. It is · to judge whether resection is important to remember that chest possible (i.e. the extent of the radiographs (and possibly CT scans of lesion and relation to vascular the lungs) may avoid unnecessary and biliary anatomy) investigations by demonstrating that The importance of a careful history the patient has metastatic disease, and examination has already been rendering further investigation and emphasized. Particular attention is surgery futile. Solid lesions which are given to details of previous surgery, multiple and bilobar are unlikely to be malignancy or liver disease. The treated by liver resection and may clinical features and organ of origin of reasonably be biopsied under the mass should be assessed. Large ultrasound guidance, provided there right adrenal or kidney tumours may are no other contraindications. Biopsy mimic liver tumours. Liver function of a liver mass may be performed tests, serum tumour markers (a- percutaneously (with or without CT or foetoprotein, carcinoembryonic ultrasound guidance), antigen, CA 19-9) should be obtained. laparoscopically, or at . Gastrointestinal hormones and urinary The biopsy may be for cytology only 5-hydroxyindoleacetic acid for (fine-needle aspiration [FNA]) or for carcinoid tumours are measured when histology (larger-bore core biopsy). appropriate. Patients with primary Early biopsy of a solitary lesion, or lesions likely to be resected is not inflammatory process such as an advised. Not only is there a risk of empyema of the gallbladder or a bleeding from vascular tumours, but perinephric abscess, or as a result of tumour dissemination into the penetrating trauma. In 15% of cases peritoneal cavity and along the needle no cause can be found (“cryptogenic track following percutaneous needle abscesses”). Compromised host biopsy may occur8. Sampling and defenses have been implicated in the interpretational errors and infection development of cryptogenic abscess can also occur. Fine-needle aspiration and may play a role in the aetiology of cytology is safer, but is more difficult to most hepatic abscesses. Liver interpret and has a higher false- abscess occur in children with negative rate for diagnosing tumours. leukaemia and other immune Hypervascular masses, coagulopathy, disorders. Diabetes mellitus has been and ascites are contraindications to noted in 15% of adult patients with percutaneous core biopsy. FNA pyogenic liver abscess. Uncommon biopsy is generally safe under these causes are due to secondary bacterial circumstances. In the evaluation of infection of an amoebic abscess or any liver mass, percutaneous biopsy hydatid cyst. should be performed only if it can reasonably be expected to obviate the Bacteriology need for . Most patients with symptomatic masses In most pyogenic liver abscesses a would be considered for laparotomy, polymicrobial infection is present with making preoperative histology predominantly endogenous gram superfluous. Biopsy of a irresectable negative aerobic and anaerobic suspected primary or metastatic organisms. Most organisms are of malignancy can spare the patient an bowel origin. Escherichia coli, unnecessary laparotomy. La Klebsiella pneumoniae, Bacteroides, paroscopic biopsy can also be used to enterococci, anaerobic streptococci evaluate liver masses and to avoid and microaerophilic streptococci are laparotomy. most common. Staphylococci, haemolytic streptococci, and PYOGENIC LIVER ABSCESS Streptococcus Milleri are usually found if the primary infection is bacterial Liver abscesses are caused by endocarditis or dental sepsis. bacterial, parasitic or fungal infection. Immunosuppression due to AIDS, Pyogenic abscesses account for three- quarters of hepatic abscess in intensive chemotherapy and developed countries. Elsewhere, transplantation has resulted in an amoebic abscesses are more frequent increase of involvement by fungal and and, world-wide, are the commonest opportunistic organisms. cause of liver abscesses. Aetiology TABLE 1 Causes and origin of Pyogenic liver abscess Most pyogenic liver abscesses occur secondary to infection originating in Biliary tract the . Cholangitis due to · Stones stones or strictures is the commonest cause (Table 1). Abdominal infection · Cholangiocarcinoma due to diverticulitis or inflammatory · Strictures bowel disease may spread through the portal vein to the liver. Less · Sclerosing cholangitis commonly bacteraemia occurs via the Hepatic artery hepatic artery from a distant site such · Dental infection as dental sepsis or endocarditis. Other routes of spread are by direct · Bacterial endocarditis extension from an adjacent · Intravenous drug abuse Portal vein aminotransferases are marginally elevated. On plain abdominal film, · Appendicitis hepatomegaly may be seen, · Diverticulitis sometimes with an air fluid level in the

· Crohn's disease abscess cavity (Figure 6). The right diaphragm is usually elevated with a · Pelvic sepsis pleural reaction or pneumonic Direct extension consolidation.

· Gall bladder empyema

· Perforated peptic ulcer

· Perinephric abscess

Trauma

Iatrogenic

·

· Percutaneous biliary stent drainage

Cryptogenic

Secondary infection of liver cyst

Clinical Features

The classic presentation is with Figure 6: CXR with Air Fluid Level in abdominal pain, swinging pyrexia and Liver Abscess nocturnal sweating, vomiting, anorexia, malaise and weight loss. Ultrasound is the preferred first line The onset may be insidious or occult scan as it is non-invasive, cost- in the elderly. Single abscesses tend effective and accurate. A CT scan is to be gradual in onset and are often useful to identify other intra-abdominal cryptogenic. Multiple abscesses are abscesses (Figure 7). ERCP is used associated with more acute systemic to define the site and cause of biliary features and the cause is more often obstruction. Identification of the identified. Clinically the liver is organism by ultrasound guided enlarged and tender. Percussion over aspiration is an essential diagnostic the lower ribs aggravates the pain. step. The spleen may be palpable in chronic cases. Ascites is uncommon. Clinical jaundice occurs only in the late stage unless there is suppurative cholangitis. Some patients do not have right upper quadrant pain or a hepatomegaly and an initial diagnosis is a fever of unknown origin.

Laboratory Investigations In two-thirds of patients there is a marked leucocytosis, although the Figure 7: CT with multiple Cholangitic white count may be normal in seriously Abscesses ill patients. The ESR is usually markedly raised with an anaemia of Treatment chronic infection. The alkaline phosphatase is generally raised with Treatment of pyogenic liver abscess hypoalbuminaemia. The serum includes antibiotic therapy and evacuation of the abscess by better patient acceptance. Open percutaneous aspiration, or catheter or surgical drainage is used when surgical drainage. Antibiotics should antibiotic therapy and percutaneous be started promptly. The appropriate aspiration or catheter drainage have selection is based on the spectrum of failed because of radiologically organisms likely to be isolated. Initial inaccessible abscesses, or very large, empiric broad-spectrum parenteral multiloculated abscesses, or where broad-spectrum antibiotic therapy there is underlying intra-abdominal should include penicillin, an disease such as biliary tract stones or aminoglycoside and metronidazole intra-abdominal sepsis that requires which are adequate for E coli, K surgery. In all cases an underlying pneumoniae, Bacteroides, cause should be sought and treated. enterococcus and anaerobic Acute biliary obstruction with streptococci. In the elderly and those cholangitis must be relieved urgently with impaired renal function a third- and can usually be done via generation cephalosporin should be endoscopic papillotomy and if used instead of an aminoglycoside. necessary, insertion of a temporary Metronidazole is effective against both biliary stent. anaerobes and amoebiasis. Penicillin Early diagnosis, treatment with is the drug of choice for Strep milleri appropriate antibiotics and selective infections which are usually resistant drainage have substantially reduced to metronidazole. In patients allergic mortality. Adverse prognostic factors to penicillin, the combination of increasing mortality include the vancomycin, an aminoglycoside, and presence of shock, adult respiratory metronidazole will provide appropriate distress syndrome, disseminated and effective cover. Ampicillin should intravascular coagulation, be added if Strep faecalis is cultured. immunodeficiency states, severe The regimen may be modified later hypo-albuminaemia, diabetes, according to the results of cultures. ineffective surgical drainage and The length of antibiotic therapy is associated malignancy. based on the number of abscesses, the clinical response, and the potential AMOEBIC LIVER ABSCESS toxicity of the chosen regimen. Some 10% of the world's population Patients with multiple biliary are chronically infected with abscesses should receive 4 weeks of Entamoeba histolytica. Amoebiasis antibiotic therapy. A shorter antibiotic constitutes the third leading parasitic course may suffice for a small, solitary cause of death, surpassed only by abscess that has been adequately malaria and schistosomiasis. drained. Initially, antibiotic therapy is Entamoeba histolytica is ubiquitous given parenterally. In patients with a worldwide distribution. The requiring a prolonged course of prevalence of infection varies widely, antibiotics, appropriate oral agents and is most frequently encountered in may be used after 2 weeks of systemic tropical and subtropical climates. therapy. Overcrowding and poor sanitation are Antibiotic therapy alone is effective the major environmental predisposing only in a small number of cases and factors and the brunt of disease is most pyogenic liver abscesses initially borne by the poor and lower require ultrasound or CT scan guided socioeconomic groups within percutaneous aspiration or catheter developing nations. drainage. The advantages of percutaneous drainage include Pathogenesis avoiding general anaesthesia and an Parasite transmission is via the faeco- operative procedure, shorter oral route with the ingestion of viable hospitalization, easier nursing and protozoal cysts. The cyst wall abscess and is useful when aspiration disintegrates in the and is necessary to establish the motile trophozoites are released which diagnosis. Ultrasound is also used to migrate to the large bowel where assess the response to therapy. pathogenic strains may cause invasive Serological tests provide a rapid disease. Mucosal invasion results in means of confirming the diagnosis, but flask-shaped ulcers through which may be misleading because of amoebae gain access to the portal previous infection in endemic areas. venous system. The abscess is Indirect haemagglutination titres for usually solitary and involves the right Entamoeba are elevated in over 90% lobe in 80% of cases. The abscess of patients. In areas where contains sterile pus and reddish-brown amoebiasis is uncommon, delay in (“anchovy paste”) liquefied necrotic diagnosis may occur because the liver tissue. Amoebae are disorder has not been considered. occasionally present at the periphery Pain or tenderness in the right upper of the abscess. quadrant may lead to a suspicion of other liver, gall bladder, duodenal or Clinical Presentation pancreatic disease. A history of travel The duration of symptoms ranges from abroad to an endemic area and a a few days to several weeks before raised right diaphragm on X-ray should presentation. Pain is a prominent lead to the diagnosis. Major feature and the patient appears toxic, complications occur either as a result febrile and chronically ill. Fever (38- of secondary infection or rupture into 0 39 C) is characteristically intermittent adjacent structures such as pleural, with night sweats and weight loss, pericardial or peritoneal spaces. Two- nausea, vomiting, cough and thirds of ruptures occur dyspnoea. The liver is enlarged with intraperitoneally and one-third maximal tenderness over the abscess. intrathoracically.

Diagnosis Treatment The diagnosis is based on clinical, Supportive measures such as serological and radiological features. adequate nutrition and pain relief are The patient is usually resident in or important. The mainstay of drug has visited an endemic area recently, therapy is metronidazole 800 mg three although there may be no history of times a day for 5 days, which has a preceding diarrhoea. A leucocytosis cure rate of 95%. Clinical symptoms with 70-80% polymorphs (eosinophilia usually improve dramatically within 24 is not a feature), a raised ESR and hours. Lower doses of metronidazole moderate anaemia are common. In are often effective in invasive disease severe disease with multiple but may fail to eliminate the abscesses, elevated alkaline intraluminal infection and so clinical phosphatase and bilirubin levels occur. relapses can occur. After the amoebic Stool examination may reveal cysts, or liver abscess has been treated in the case of dysentery, diloxanide furonate 500 mg 8 hourly haematophagous trophozoites. for 7 days is used to eliminate Radiological imaging is essential. intestinal amoebae. Chest x-ray shows a raised, poorly moving, right diaphragm with Most uncomplicated abscesses atelectasis or pleural effusion. After resolve with metronidazole treatment rupture through the diaphragm, a alone. Ultrasound guided needle pleural effusion, lung abscess, aspiration is performed if serology is consolidation or, rarely, bronchopleural negative, or the abscess is large (>10 fistula, may be present. Ultrasound cm), if there is no satisfactory shows the size and position of the response to treatment, or there is impending peritoneal, pleural or a fox or wolf and the intermediate host pericardial rupture. The conservative a vole or lemming. regimen described above has been Human infection follows accidental adopted in most endemic areas. ingestion of ova passed in dog faeces. Surgical drainage is required only if The ova penetrate the intestinal wall the abscess has ruptured with and pass through the portal vein to the amoebic peritonitis or if there is no liver, lung and other tissues. Hydatid response to medical treatment in spite cysts can develop anywhere in the of needle aspiration or catheter body but two–thirds occur in the liver, drainage. and one quarter involve the lungs. The mature cyst has 3 layers, an inner HYDATID DISEASE germinal lining, and a middle acellular Hydatid disease in man is caused by laminated layer, which is surrounded the dog tapeworm, Echinococcus by an outer fibrous host pericyst layer. granulosus. Dogs are the definitive In older cysts the laminated and host, shedding ova in the faeces, pericyst layers may become calcified. which infect the natural intermediate The germinal layer produces daughter hosts such as sheep or cattle. Hydatid cysts and brood capsules containing disease is endemic in many sheep- scoleces capable of spreading the raising countries. Increasing migration disease. and world travel have made hydatidosis a global problem of A liver hydatid may present either with increasing importance. liver enlargement and right upper quadrant pain due to cyst pressure or Echinococcus is the smallest of all acutely with a complication. Hydatid adult tapeworms, measuring 6 mm in cysts progressively enlarge. length. Several closely related Complications include cyst rupture into species of Taenia echinococcus have the peritoneal cavity, resulting in the potential of causing disease in urticaria, anaphylactic shock, man. Granulosus is cosmopolitan, eosinophilia and implantation into multilocularis is limited to the northern omentum and other viscera. Cysts hemisphere while vogeli and may compress or erode into a bile duct oligarthrus are indigenous to Central causing pain, jaundice or cholangitis or and South America. The life-cycle the cyst may become infected typically involves 2 hosts. The secondary to a bile leak. Perforation definitive host is a carnivore, the adult through the diaphragm and worm living in the host small bowel communication with the lung and attached to mucosa and shedding its bronchus (“coughing up grape-skins”) eggs in the gut. The ova are resistant is uncommon. Ultrasound and CT to drying and remain viable for several scan demonstrate the size, position weeks after being passed. The and number of liver cysts (Figure 8). intermediate host is a herbivore, which ingests the ova while grazing. The ova hatch in the bowel, enter the portal circulation and develop in the liver. The life-cycle is completed when the dog eats contaminated offal. Man is an unwitting accidental intermediate host and contracts the disease when ova are swallowed after contact with an infected dog. Preventative campaigns depend on interrupting this life-cycle. E. multilocularis is uncommon; the primary host is usually Figure 8: CT showing Right Lobe Liver Hydatid The scan should examine the entire effects which are bone-marrow abdomen for extrahepatic cysts. In depression, liver and renal toxicity. 10% of patients the chest X-ray will New radiologically guided aspiration also show a lung hydatid. Eosinophilia techniques are being assessed in is present in 40% of patients. The selected patients. diagnosis is confirmed by serologic haemagglutination and complement LIVER TUMOURS fixation tests. ERCP is used to Tumours of the liver may be cystic or demonstrate a cyst communication solid, benign or malignant. The with the bile ducts if the patient is majority are asymptomatic, with jaundiced or if the serum alkaline normal liver function tests and phosphatase, gamma GT or bilirubin increasingly are discovered as are elevated. incidental findings during ultrasound or All symptomatic cysts require surgery computed tomography. Many require to prevent complications. Small no treatment, but it is important for densely calcified cysts (“golf-ball” non-specialists to identify lesions that appearance) signify death of the require further investigation and to parasite and require no further avoid unnecessary biopsy, which is treatment. Surgery requires careful now rarely indicated. isolation of the operative field by abdominal swabs soaked in scolicidal Cystic liver lesions fluid to prevent spillage and Cystic lesions of the liver are easily implantation. Because the cyst wall is identified by ultrasound scan. The fragile, care must be taken to avoid majority (>95%) are simple cysts rupturing the cyst. If scoleces spill into which are estimated to be present in the peritoneal cavity, the parasite will 1% of the population. These are thin form new cysts. During operation the walled, containing clear fluid without cyst fluid is aspirated and replaced by septa or debris and are surrounded by a scolicidal agent such as 0.5% normal liver tissue. Asymptomatic sodium hypochlorite or 0.5% silver simple cysts are regarded as nitrate solution. Scolicidal solutions are congenital malformations and require not injected if there is a bile leak no further investigation or treatment, because of possible chemical injury to as complications are rare. Aspiration biliary epithelium. Once the cyst is and injection of sclerosants should be decompressed, the cyst and contents avoided as it may result in bleeding are carefully shelled out by peeling the and infection, and does not result in endocyst off the host ectocyst layer resolution of the cyst. Rarely simple along its cleavage plane. The fibrous cysts can grow very large and produce host wall of the residual cavity is compressive symptoms that are carefully examined for bile leakage managed by limited surgical excision from biliary-cyst communications and of the cyst wall (cyst fenestration). these are sutured closed. The cavity is drained and filled with omentum. Two or more cysts are present in 50% Conservative surgery is effective in of patients with simple cysts. True most cysts and liver resection is polycystic liver disease is seen as part seldom necessary. Albendazole is of adult polycystic kidney disease given for 2 weeks postoperatively to (APKD), an uncommon autosomal prevent recurrence. Drug therapy is dominant disease that progresses to also used in patients unfit for surgery, renal failure (Figure 9). Multiple renal in those with disseminated, recurrent cysts are always present and usually or inoperable disease and or as an precede liver cyst development. Liver adjuvant in complex surgery. These function is normal and most patients drugs must be used cautiously and the are asymptomatic. Occasionally pain patients carefully monitored for side- due to liver capsule distension requires cyst fenestration.

Figure 9: Polycystic Disease of the Figure 10 CT showing haemangioma Liver of liver Thick walled cysts, those containing septae or nodules or echogenic fluid, may represent cystic tumours (cystadenoma, cystadenocarcinoma) or infective cysts (hydatid cysts and abscesses), and should be referred for specialist surgical opinion.

BENIGN TUMOURS OF THE LIVER Benign liver tumours are common, usually asymptomatic and the importance of most is only in differentiation from malignant lesions.

Haemangiomas Figure 11 MRI Scan of Liver These are the commonest benign solid Haemangioma tumours of the liver with a reported incidence in the general population of Liver Cell Adenoma (LCA) and around 3%. Those over 10cm in Focal Nodular Hyperplasia (FNH) diameter occasionally produce non- These uncommon tumours both occur specific symptoms of abdominal predominantly in women of discomfort and fullness, and rarely childbearing age. LCA became more fever thrombocytopaenia and prevalent with the widespread usage hypofibrinogenaemia. Malignant of oral contraceptive medication transformation and spontaneous (OCM) in the 1960’s but is now less rupture rarely, if ever, occur. CT is common with the reduced oestrogen usually sufficient to diagnose most content of modern contraceptives. haemangiomas and in equivocal cases Most patients present with pain due to magnetic resonance imaging (MRI) or rapid tumour growth, intratumour 99 Tc-labbeled red blood cell haemorrhage or the sensation of a scintiscanning are diagnostic. mass. LCA has a 10% risk of rupture Angiography and biopsy are now and malignant transformation is found rarely required (Figure 10, 11) in 10% of resected specimens. FNH is not related to OCM usage, is usually asymptomatic and is not premalignant. FNH classically demonstrates a central stellate scar on CT and MRI and does not require treatment unless deterioration in liver function, an acute symptomatic. Patients with LCA complication (ascites, encephalopathy, require liver resection to prevent the variceal bleed, jaundice) or risks of haemorrhage and malignant development of upper abdominal pain transformation. and fever. Ultrasound is capable of demonstrating most tumours, and There remains a small proportion of demonstration of a discrete mass patients in whom a firm radiological within a cirrhotic liver together with an diagnosis cannot be made and in alpha-fetoprotein (AFP) level of which distinction from a malignant >500ng/ml is diagnostic, and liver hepatic tumour is uncertain. biopsy is unnecessary. Surgical Symptomatic patients require surgical resection is the only treatment that can resection, which in specialist centres offer cure. However due to local has a mortality of <5%. Surgical tumour spread and severity of pre- excision should also be the existing cirrhosis, such treatment is management of choice in most feasible in less than 20% of patients asymptomatic patients rather than liver even in experienced centres. Five biopsy, since the latter may yield year similar to those for surgery. For inadequate samples and carries the larger tumours, transarterial risks of haemorrhage and tumour embolisation may have some survival seeding. Furthermore histological advantage. Iodised oil (lipiodol) and distinction between FNH and cirrhosis, cytotoxic drugs (cisplatin or and LCA from well-differentiated doxorubicin) are injected into the hepatocellular carcinoma (HCC) may hepatic artery via a catheter inserted in be very difficult with tru-cut biopsy or the femoral artery (Figure 12). The fine needle aspiration samples. lipiodol is rapidly cleared by normal MALIGNANT TUMOURS hepatocytes but not by tumour cells and is concentrated in the tumour. Hepatocellular carcinoma Tumour necrosis undoubtedly occurs but it remains to be seen if this results Although uncommon in the UK, in a prolonged survival advantage. accounting for only 2% of all cancers, worldwide there are over 1 million new cases per annum with annual incidence rates of 100 per 105 males in parts of Southern Africa and SE Asia. The incidence of HCC is closely related to areas with high carrier rates of hepatitis B and C and >80% of HCC’s occur in cirrhotic livers. Once viral infection is established it takes approximately 10 years for patients to develop chronic hepatitis, 20 years to develop cirrhosis and 30 years to develop HCC. In African and Asian Figure 12: Hepatic Angiogram of HCC countries Aflatoxin, produced as a result of contamination of imperfectly In patients without cirrhosis, HCC’s stored staple crops by Aspergillus usually present late with an abdominal flavus, appears to be an independent mass and have normal liver function. risk factor in the development of HCC, CT has a greater sensitivity and probably through mutation of the p53 specificity than ultrasound, particularly suppressor gene. in tumours smaller than 1cm (Figure 13). AFP is elevated in 80% of patients In patients with cirrhosis, the diagnosis but may also be elevated in patients should be suspected when there is with other tumours (testicular, gastric and pancreatic). Fibrolammelar metastases is zero, compared with an carcinoma is an important subtype of overall 5 year survival following HCC, occurring in non-cirrhotic livers resection of 30%. Tumours need not in patients without hepatitis B or C. It be solitary nor even confined to a accounts for 15% of HCC in the single lobe, although outcome is worse Western Hemisphere and is important in patients with resectable bilateral because of the favourable prognosis, disease. The only limitation to liver with a 5 year survival of 50% following resection for colorectal metastases is resection. the ability to leave enough tumour-free liver to function, which depends on the extent and distribution of the tumour burden and the general fitness of the patient and their liver. The capacity of the liver to regenerate is legendary and a fit patient with a healthy liver can undergo a 60% resection that will completely regenerate in three months.

Liver resection Liver resection has advanced rapidly over the last two decades due to a Figure 13: CT of Right Lobe HCC number of key developments. First Metastatic tumours was the anatomical description by Couinaud in 1957 of the segmental Liver metastases are common and are anatomy of the liver with its division found in 40% of all patients dying with into eight segments each, supplied by carcinoma. They are most frequently its own branch of the hepatic artery, associated with carcinomas of the portal vein and bile duct. It is now (colo-rectal, possible to safely remove each of and ) but are nearly these segments individually when as common in carcinomas of the required, reducing the amount of bronchus, breast, ovary and normal liver unnecessarily removed. lymphoma. With the exception of Subsequently surgical techniques colorectal liver metastases, tumour have been developed to dissipate the deposits are usually multiple and liver parenchyma, either by crushing seldom amenable to curative with a clamp or by ultrasonic resection. dissection, allowing the vascular and biliary radicals to be individually Colorectal liver metastases ligated. Occlusion of the vascular Around 8-10 % of patients undergoing inflow (Pringle manoeuvre) and where curative resection of colorectal possible the appropriate hepatic vein, tumours have isolated liver together with lowering of the central metastases suitable for liver resection, venous pressure during survival is equivalent to around 1000 patients in around 15%, with average operative the UK per annum. Half will have mortality rates of 12%. metastases present at the time of For patients with non-operable HCC diagnosis of the primary (synchronous) less than 5cm in diameter, injection and most of the rest will develop within with 95% alcohol under ultrasound the next 3 years (metachronous guidance has minimal morbidity and metastases). has been shown to result in 5 year Without surgical resection the 5 year survival figures survival rate for all patients with liver Resection, have reduced blood loss making blood transfusion unnecessary in 80% of liver resections. Improvements in postoperative care including epidural anaesthesia to reduce postoperative chest infections, and the ability to manage postoperative fluid or bile collections by radiological or endoscopic drainage, have resulted in a median hospital stay of 7-10 days and mortality of <3%. As a result liver resection has evolved from a hazardous bloody procedure, into a routine operation.

This work is licensed under a Creative Commons Attribution 3.0 Unported License.