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SURGICAL WEBSITES             KIDNEY SURGERY         POSTGRADUATE SURGERY LINKS 

BREAST DISEASE     Breast cancer Breast lump Breast awareness Breast calcifications  Breast cysts Breast pain Duct ectasia Fat necrosis Fibroadenoma Hyperplasia Intraductal papilloma Phyllodes tumour Sclerosing adenosis                                                                                                                                                 

LIVER ABSCESS      Anatomy of liver Physiology of liver Method of examination of liver Haematology of liver disease. Amoebic liver abscess .Pyogenic liver abscess. Percutaneous needle aspiration of liver abscess. Case study.  Result Result continued  Discussion                                                                 

CHOLECYSTECTOMY    Introduction   Historical Review  Anatomy of Gallbladder Physiology of Gallbladder Physiologic effects of pneumoperitoneum Pathology  of Gallbladder Investigations Pre- operative preparation of laparoscopic cholecystectomy Contraindications  Treatment modalities for gallstones.  Anaesthesia                                                                                                                       

INGUINAL HERNIA    HOW SURGICAL OPERATION IS DONE     THYROID EXAMINATION MANAGEMENT OF SEVERELY INJURED PATIENT      SEPSIS AND MULTIPLE ORGAN FAILURE CHEST TRAUMA     BRONCHOGENIC CARCINOMA     TETANUS AND ANAEROBIC INFECTIONS 

HAEMATOLOGY OF LIVER DISEASE

GENERAL FEATURES

       Both parenchymal hepatic disease and cholestatic jaundice may produce blood coagulation defects. Diminished erythrocyte survival is frequent. Dietary deficiencies, alcoholism, bleeding and difficulties in hepatic synthesis of proteins are used in blood formation or coagulation add to the complexity of the problem.

       Spontaneous bleeding, bruising and purpura, together with a history of bleeding after minimal trauma such as venepuncture, are important indications of bleeding tendency in patients with liver disease than are laboratory tests.

 

BLOOD VOLUME

       Plasma volume is frequently increased in patients with cirrhosis, especially with ascites and also with long standing obstructive jaundice or with hepatitis. This hypovolaemia may partially, and sometimes totally, account for a low peripheral haemoglobin or erythrocyte level. Total circulating haemoglobin is reduced in only about half the patients.

 

HAEMOGLOBIN

Anaemia is very common in liver abscess. It is usually normochromic and normocytic in about half of its patients, and found that it was related to the duration of the symptoms and signs of the abscess. Also anaemia was severe when the size of the abscess was large. In a study by Sattar and Muhammad, anaemia was the commonest laboratory finding in the paediatric age group ²³. Most authorities believe that this anaemia responds to specific amoebicidial / antibiotic therapy and not to haematinics. In 1993 Nguyen discovered the cause of anaemia as hepatic abscess, and occult malignancy ²⁴.

 

WHITE CELL COUNT

There is moderate to massive leucocytosis accompanied by an absolute or relative increase in neutrophils. Although 25 percent of the patients may have leucocyte count below 11,000 per cu mm., leucocytosis between 15,000 and 25,000 per cu mm. Is common with neutrophil count up to 72-75%. Higher counts may be present in secondarily infected abscesses. Eosinophil count is usually normal unlike in other parasitic infections. Normal leucocyte count is found in two-thirds of his patients and therefore believed that it cannot be taken as a very reliable diagnostic test in liver abscess.

 

ERYTHROCYTE SEDIMENTATION RATE

       This is usually elevated. Leucocytosis is produced by factors independent of those causing an elevation in ESR. This would mean these two haematological investigations are a measure of different functional derangement both probably non specific. Fibrinogen is an acute phase reactant and is elevated in hepatic amoebiasis giving a raised erythrocyte sedimentation rate. It is usually more than 100 mm in the first hour

 

Erythrocyte changes

       The red cell may be hypochromic. Anaemia follows gastro-oesophageal bleeding and is enhanced by thrombocytopaenia and disturbed blood coagulation. Epistaxis, bruising and bleeding gums add to anaemia.

       The erythrocytes are usually normocytic. This is combination of the microcytosis of chronic blood loss and in macrocytosis inherent in patients with liver disease.

 

Folate and B₁₂ metabolism

       The liver stores folate and converts it into active storage form tetrahydrofolate. Folate deficiency may accompany chronic liver disease, usually in alcoholic. This is largely due to dietary deficiency. Serum folate levels are low. Folate therapy is useful. The liver also stores vitamin B₁₂. Hepatic levels are reduced in liver disease. When hepatocytes become necrotic the vitamin is released into the blood and high serum B₁₂ levels are recorded. This is shown in hepatitis, active cirrhosis with primary liver cancer. Values in cholestatic jaundice are normal.

LEUKOCYTES

       Leukocytosis accompanies cholangitis, fulminating hepatitis, alcoholic hepatitis, hepatic abscess and malignant disease. Atypical lymphocytes are found in the peripheral blood in virus infection.

 

PLATELETS

Abnormalities in platelet number, structure function are common in patients with all forms of liver disease. Reduced numbers, rarely severe, are due to increased splenic sequestration. This is related to a greatly increased splenic pool. Increased destruction of platelet is minimal.

 

The liver and blood coagulation

       Disturbed blood coagulation in patients with hepato-biliary disease is particularly complex. It has now become clear, particularly as a result of hepatocyte cell culture studies, that the liver is principal site of synthesis of all the coagulation proteins with the exception of von Willibrand factor and the fibrolytic proteins.

       The liver also clears activated clotting factors from the blood. Disseminated intravascular coagulation can follow acute hepato-cellular necrosis.

 

TESTS OF COAGULATION

       The prothrombin time (PT) before and after 10mg vitamin K intramuscularly is the most satisfactory test for coagulation defect in patients with hepato-biliary disease. It is also most sensitive indicator of hepato-cellular necrosis. The activated partial thromboplastin time (aPTT) is sometimes performed and is slightly more sensitive than (PT). Prolongation indicates not only deficiency of the prothrombin complex but also factor XI and XII.

 

STOOL EXAMINATION AND SIGMOIDOSCOPY

STOOL EXAMINATION

If it reveals cysts or vegetative form of E. Histolytica, it becomes valuable in diagnosis. However in endemic areas, where the incidence of carriers is high, presence of cyst of E. Histolytica should not be given too much importance.

 

SIGMOIDOSCOPY

It is a useful investigation and may be positive in as many as 30 to 40 percent of cases. Any exudate seen on sigmoidoscopy must be obtained for parasitological examination. It is important to use a glass pipette or metal instruments since amoeba adhere to cotton swabs. If the diagnosis of amoebic ulcer is doubtful, a biopsy may also be taken to demonstrate E. Histolytica in histopathological sections.

 

 

RADIOLOGY AND HEPATIC IMAGING

X-ray chest

       An important sign is the elevation of the right dome of the diaphragm. This is diagnosed if the difference between the two dome of diaphragm is 2.5 cms or more. Pleuro-pulmonary complications may occur. In such events radiological signs may include diffuse or patchy pneumonitis, solitary or multiple lung abscesses a broncho-pleural fistula or massive pleural effusions.

       Elevation of diaphragm is shown in figures 11 and 12.

 

Plain radiography of abdomen

       In liver abscess the plain X-ray abdomen may show an enlarged liver and the diagnosis may be suspected by the asymmetry of the liver margin as outlined by the lung or intestinal gas shadow. Yoshida and colleagues has reported abdominal x-ray examination in a case of liver abscess demonstrating multiple branching lucencies in the liver secondary to gas in the portal system due to infection with Bacteriodes fragalis ²⁵.

Fluroscopy

       The fluroscopic examination of the upper abdomen and chest if possible should be carried out with image intensifier. The advantage of fluoroscopy over radiology is that the movements of the diaphragm could be visualised.

Hepatic imaging

       Clinical suspicion of a liver abscess mandate an investigation of the liver for the evidence of liver abscess by radionuclide scan, ultrasound scan or CT scan ²⁶. It is an essential step in diagnostic work up of most hepatic problems. It may show some types of diffuse disease.

Radioisotope scanning

^99mTechnetium scanning

         ^99mTc-labelled tin colloid and colloid of human albumin are taken up by the reticulo-endothelial cell. Introduced in 1960s they were used to detect hepatic tumours, but could not differentiate solid from cystic ones. Radioisotope scanning is effective in diagnosing liver abscess in 24 hours ²⁷. Lesions 4cms in diameter are usually demonstrated, but sensitivity falls below this size. Reduced patchy hepatic uptake with increased activity from bone marrow and spleen denote chronic liver disease. Ultrasound has replaced isotope scanning for the detection of space occupying lesions, and can show irregular liver outline and change in echogenicity in cirrhosis. Gallium citrate is taken up by liver tumours and by inflammatory process like liver abscess. Gallium scanning retains a role in the complex patients with chronic sepsis of unknown origin when a focus of increased radioactivity may suggest an inflammatory collection. ^99mTc IDA derivatives have a role in imaging of biliary tract.

      Different components of liver perfusion can be calculated.

Indications of scanning in the case of liver abscess

1. To confirm diagnosis.

2. If there is difficulty in deciding where to tap.

3. In the case of P.U.O. with enlarged liver.

4. In the cases of pericarditis with effusion.

5. False localisation of the abscess is often an indication.

 

LTRASOUND SCAN

       The accuracy of the ultrasound for detecting liver abscess is high ³¹. Most imaging units use real time high resolution. US scanners US take only a few minutes to perform

       Ultrasound is the first choice examination when a hepatic abscess is suspected. It is very helpful in diagnosing it and if cholecystitis is suspected ³². There is an area of reduced echogenicity with or without a surrounding capsule. Rarely pus has a similar echogenicity to liver and the abscess is not detected. Clinical features should draw attention to the possibility of the false negative results and CT ordered as a second option. Therapeutic aspiration or catheter drainage may follow ³³.

    

COMPUTED TOMOGRAPHY (CT) SCANNING.

       The liver is displayed as a series of adjacent cross sectional slices each of 7-10 mm thickness. The hard copy scan is depicted as seen from below. Typically 10-12 images are needed to examine the whole liver.

       The CT scan demonstrates detailed anatomy across the whole abdomen at the level of the slice. Oral contrast is usually given to help identify stomach and duodenum. Enhancement by intravenous contrast medium, given as a bolus, an infusion or by arterioportography, demonstrates blood vessels, followed by hepatic parenchyma. There is renal excretion of contrast. Intravenous cholangiography as a source of contrast is very occasionally used to delineate the biliary system. CT gives good visualisation of adjacent organs particularly kidneys, pancreas, spleen and retroperitoneal lymph nodes.

       CT demonstrates focal hepatic lesions and some diffuse conditions. Advantages over ultrasound are that it is less operator dependent and hard copy films can be readily understood by clinicians. It is more reproducible and obese patients are well suited for CT. Gas filled bowels rarely produce artefacts-solved by altering the patient’s position. Pain, postoperative scars and dressings are no hindrance. CT guided biopsy and aspiration are accurate.

       The liver appears homogenous with an attenuation value given (in Hounsfield units) similar to kidney and spleen. Portal vein branches are seen at the hilum. Intravenous enhancement is necessary to confidently differentiate these from dilated bile ducts. Hepatic veins are usually seen. Enhanced CT shows the portal vein and can be used to check patency. Invading tumour or obstructing thrombus may be seen. Cavernomatous transformation can be recognised with two or more enhancing vessels in place of obstructed portal vein. Doppler ultrasound however remains the better technique to demonstrate the abnormalities of the portal vein.

       Normal bile ducts, both intrahepatic and extrahepatic, are difficult to see. The shape of liver any anatomical abnormalities or lobe atrophy is seen. Liver volume can be calculated from the slices taken but is a research tool. Computed tomography reconstruction of the actual slices has been performed to define the size of the lesion but it is not widely used.

       CT can detect space occupying lesions of 1cms and more in diameter. Both unenhanced and enhanced scans should be done. Thus a filling defect on an unenhanced scan may be rendered isodense by intravenous contrast injection and missed. Conversely, an area isodense with normal liver on the unenhanced scan may only be seen after enhancement.

       Abscesses usually show a low attenuation than normal liver. Aspiration under guidance is possible as in the case of ultrasound. An enhanced rim around the abscess is said to be more characteristic of amoebic abscess ³⁷. An important function of CT scan is the differentiation from the conditions mimicking liver abscess on ultrasound scan. The CT is not only used as a diagnostic tool but also as a therapeutic device for CT drainage of the abscess ³⁸. Under CT control it is very easy to drain multiple abscesses and also gives safe and accurate access to the left sided abscess.

       An important function of CT, more so than in US, is to define an anatomy for the surgeons considering hepatic resection. The segmental position of the lesion can be identified. To establish the extent of hepatic metastases before surgery, CT-arterioportography or dynamic incremental-bolus CT are more accurate than routine enhancement to detect small lesions.

       CT scans are shown in figure 18 and 19.

 

MAGNETIC RESONANCE IMAGING

       This is the most expensive scanning technique, at approximately the six times the cost of US and twice that of CT. Experience is rapidly accumulating in liver disease. It appears at least comparable with CT and may be better. This method depends on detection of energy released from hydrogen protons after forcible alignment in a strong magnetic field. The technique is safe. Patients with cardiac pacemakers and internal magnetic materials (clips metallic foreign bodies) are excluded, as are pregnant patients; it is difficult to scan and monitor the ventilated patients from intensive care.

       Several measurements of tissue can be made but those most commonly employed are the relaxation times T₁and T₂ and proton density. Tissue appears greatly different according to mode used. Blood vessels are visualised without the need for contrast material. There is excellent contrast resolution (better than CT) and good spatial resolution as CT). As scanning times (currently 5-10 minutes for each sequence) reduced with technological advances, artefact from respiratory movements particularly in breathless patients will decrease and spatial resolution will improve. Multiple planes (axial, coronal, and sagittal) can be reconstructed according to the need. Reproducibility is good. Tissue characterisation is possible.

              T₁ relaxation time is the time taken for hydrogen proton to re-align within the external magnetic field after radio wave pulse. T₂ relaxation time describes the rate at which the axes of the proton move out of phase with other because of the differing electromagnetic influences of the adjacent protons. Protein density simply depicts the number of protons per unit area per unit area. Tissue responds differently to MRI process and scans can therefore characterise cyst fluid, sub-acute and chronic blood, fat neoplasm, fibrotic tissues and vessels.

                On T₁ weighted (T₁W) scans the liver usually appears grey and homogenous, with a signal greater than spleen. On T₂W the hepatic signal is less than that from spleen. Dilated bile ducts are easily seen.

       Normal blood vessels usually appear black with T₁W and T₂W scans because the energy donated during the radio-pulse has passed out the slice with blood flow by the time the return signal is recorded. With gradient echo sequence, used only in selected cases, recording is less delayed after excitation and blood vessels may appear bright.

       Which ever technique is used, portal vein, hepatic veins, IVC and aorta are seen. Note that no contrast injection is needed for blood vessel visualisation.

       MRI can show cysts, haemangioma, primary and secondary tumour. Malignant tumours appear dark (low signal) on T₂W. Differentiation between hepatocellular carcinoma and metastases is not possible. Preliminary reports suggest that adenomatous hyperplastic nodules without dysplasia are hypo-intense on T₂W scans, differentiating them from hepatocellular carcinoma. Cavernous haemangioma is particularly bright on T₂W and can be distinguished from carcinoma using a spin echo sequence of 2000/150.

MR-SPECTROSCOPY

       MR-spectroscopy allows non-invasive evaluation of biochemical changes in tissue in vivo. Changes in molecules involved in selected areas of cellular metabolism can be detected. This technique has been applied to patients with liver disease. Phosphorus-31 spectroscopy of the liver shows changes in a variety of hepatic diseases.

 

Conclusion and choice

       The choice of technique for hepato-biliary imaging depends upon the availability of the appropriate apparatus, operator and interpreter and the problem that has to be solved. Strict diagnostic algorithms cannot be formulated that will service all units. US and CT are better in detecting lesions and characterising them. With an experienced ultrasonographer, this technique is the initial examination of choice for the majority of problems. CT can further study equivocal results if necessary.

       CT and MRI characterise most lesions better than US but are most costly and less widely available. MRI is at present the most costly method of scanning and is likely to be used in most units only for difficult problem insoluble by US or CT.

       For the diagnosis of the jaundice, US is preferred screening investigation. If necessary this may be followed by CT scanning to help in the diagnosis and to show the extent of disease.

       For the diagnosis of the gallbladder stones, US is primary method of choice. HIDA scanning provides an alternative non invasive method to US for determining bile duct obstruction, in the diagnosis of acute cholecystitis, and in demonstrating post operative biliary patency and leaks.

NEEDLE BIOPSY OF LIVER

       In a study of glycogen content of the diabetic liver and later in 1895 by Lucatello in Italy performed for the diagnosis of tropical liver abscess. Liver biopsy is helpful in establishing the severity of the liver disease ³⁹. The indication and techniques of performing liver biopsy have changed, complications are better recognised and the risks have decreased.

 

Selection and preparation of patients

 

       The patient is usually admitted to the hospital. Out patients selected must not be jaundiced or show any signs of liver failure such as ascites or encephalopathy. Out patient biopsy should be avoided in known cirrhotic patients or in those with tumours.

       Biopsy should be done using all aseptic techniques in operating theatre. During the first hour post biopsy, the pulse and blood pressure are taken every 15 minutes and then every 30minutes for next 2 hours. The patient is kept recumbent for 6 hours.

        The prothrombin should not be more than 3 seconds prolonged over controlled values after 10 mg vitamin K is given intramuscularly.

       In thrombocytopenic patients the risk of haemorrhage depends on the function of the platelets rather than on their numbers. A patient with ‘hypersplenism’ and a platelet count of less than 60 000 is much less likely to bleed than one with leukemia who has a similar platelet count.

       The patient’s blood group should be known and facilities for blood transfusion must always be available. Biopsy should not be done with tense ascites, as specimen will not be obtained.

       Nowadays diagnosis is reached more exactly and safely by imaging. Suspected amyloid disease is not a contraindication. Intra-peritoneal haemorrhage is common in haemophiliacs and may require blood transfusion. Liver biopsy should only be performed when the patients are expected to benefit from the information and where it cannot be obtained by less invasive means. Haemorrhage usually develops when least expected and when, at the time of biopsy, the risk seemed small. It might be related to factors other than peripheral clotting for instance the concentration of clotting factors in hepatic parenchyma and the failure of mechanical compression of the needle by elastic tissue. Known vascular lesions, such as haemangioma should not be biopsied.

 

Techniques

       The Menghini needle obtains a specimen by aspiration. The sheathed ‘Trucut’ is modification of the old Vim-Silverman needle. It is of particular value in cirrhotic patients. Fragmentation of the biopsy is greater with the Menghini technique but the procedure is quicker, easier and the cost of the needle is less. Complications are less than with the Trucut procedure.

       Ultrasound guided biopsy is increasing in use and is often performed along with a radiologist who prefers the use of a fine needle. This gives satisfactory result in the diagnosis of focal lesions.

       Menghini one second needle biopsy. The 1.4mm diameter is used routinely. A short needle is available for paediatric use. The tip of the needle is oblique and slightly convex towards the outside. The needle is fitted within its shaft. This internal block prevents the biopsy from being fragmented or distorted by violent aspiration into the syringe.

       Three ml of sterile solution is drawn into the syringe that is inserted through the anaesthetised tract down to but not through the intercostal space. Two ml of solution is injected to clear the needle of any skin fragments. Aspiration is now commenced and maintained. This is the slow part of the procedure. With the patient holding his breath in expiration the needle is rapidly introduced perpendicularly to the skin into the liver substance and extracted. This is the quick part of the procedure. The tip of the needle is now placed on the sterile filter paper and some of the remaining saline flushed through the needle to deposit the biopsy gently onto the paper. The piece of the tissue is transferred into fixative.

       Sedation is not given routinely before biopsy as it may interfere with the patient’s co-operation. However, analgesia is sometimes needed after the procedure for pain.

       The intercostal technique is the most frequent method. It rarely fails, provided care is taken to assess liver size carefully by light percussion. A preliminary ultrasound or CT scan is useful. A small fibrotic liver is contraindication to the procedure. After adequate local anaesthesia, the needle is inserted into 9^th intercostal space in the mid-axillary line at the end of expiration with the patient breathing quietly. The direction is slightly posterior and cranial. If an epigastric mass is present or imaging indicates left lobe disease, an anterior approach is made.

       Transvenous (transjuglar) liver biopsy. This is done by inserting the special Trucut needle through a catheter placed in the hepatic vein via the jugular vein. The needle is then introduced into the liver. It is also valuable for patients who are uncooperative or who have very small livers. Another advantage is that wedged and free hepatic venous pressure may be measured at the same time. The procedure may be attempted after percutaneous biopsy has failed. The disadvantage of this is greater complexity compared with the percutaneous approach. Although usually successful, the liver fragments are sometimes very small.

       Directed guided liver biopsy with or without inspection of the liver surface gives a high percentage of positives. The over all accuracy of diagnosis for chronic liver disease using the blind technique is approximately 81%, but this can be raised to 95% if a directed form of liver biopsy is used.

       The Biopty^TM gun uses a modified 18- or 14- gauge Trucut needle and is operated with one hand. It is fired with a fast and powerful spring mechanism. It allows precise positioning and less painful than the manual procedure. It is particularly useful for the diagnosis of tumours. Reported results for the diagnosis of focal lesions varies.

       A Surecut (0.66mm) needle liver biopsy may be used to diagnose cirrhosis when the Menghini is contraindicated. Risk of complications even following puncture of a hydatid cyst or haemangioma is minimal.

       Imaging adds to the diagnostic accuracy. A lesion is recognised under imaging and assuming coagulation and other conditions are satisfactory, a Trucut biopsy needle is advanced into it. The method of imaging includes ultrasound, CT and hepatic angiography. In patients with poor coagulation a gelfoam plug may be injected through the outer cannula of the Trucut needle after inner cutting needle, with its contained specimen has been removed. This is effective in preventing major bleeding after image guided biopsies.

Liver biopsy needle is shown in figure 20.

 

After care.

       The pulse rate is charted hourly for the first 24 hours. Routine visits should be paid 4 and 8 hours after biopsy. A very careful watch must be kept on the patients. Rest in bed is essential for 24 hours.

       During the puncture the patient may complain of a drawing feeling across the epigastrium. Afterwards some patients have a slight ache in the right upper quadrant for about 24 hours and some complain of the pain referred from the diaphragm to the right shoulder.

 

Difficulties

Failures arise in patient with cirrhosis, especially with ascites, for the tough liver is difficult to pierce and a few liver cells may be extracted, leaving the fibrous framework behind. Another difficulty may be pulmonary emphysema.

      

 

Risks and complications

The mortality from various large combined series is about 0.01%. Deaths from haemorrhage are usually in those with hopeless prognosis.

 

Pleurisy and peri-hepatitis

A friction rub caused by fibrinous perihepatitis or pleurisy may be heard on the next day. It is of little consequence and pain subsides with analgesics. Chest X-ray may show small pneumothorax.

 

Haemorrhage

       Bleeding from the puncture wound usually consists of o thin trickle lasting 10-60 seconds and the total blood loss is only 5-10 ml. Serious haemorrhage is usually intraperitoneal but may be intrathoracic from an intercostal artery. The bleeding results from perforation of distended portal or hepatic veins or aberrant arteries.

       Malignancy, age, female sex and number of attempts were the only predictable factors for bleeding.

Perforation of the capsule with intraperitoneal haemorrhage may follow transvenous biopsy.

Haemorrhage is rare in non-jaundiced.

 

 

Arteriovenous fistula

       An arteriovenous fistula shown by hepatic arteriography follows 5% of liver biopsies. Histology shows marked phlebosclerosis of the portal vein tributaries. The fistula may close spontaneously; otherwise direct hepatic arterial catheterisation and embolisation of the feeding artery can treat it

Biliary peritonitis

       This is the second commonest complication after haemorrhage Surgical management is usually necessary although conservative measures with intravenous fluids, antibiotics and intensive care monitoring may be successful.

 

Puncture of other organs

       Puncture of organs such as the kidney or colon is rarely clinically significant.

 

Infection

       Transient bacteraemia is relatively common, particularly in patients with cholangitis. Septicaemia is rare blood cultures are usually positive for E. coli.