Liver Abscess course and its management.pptx

Liver Abscess

1. Liver Abscess R.pardha venkatesh

2. Introduction A liver abscess is a space occupying suppurative lesion in the liver resulting from the invasion and multiplication of microorganisms that enter directly from an injury, through the blood vessels, or by way of the bile ducts. The liver is the organ most subject to the development of abscesses. Liver abscesses may be solitary or multiple; they may arise from hematogenous spread of bacteria or from local spread from contiguous sites of infection within the peritoneal cavity. It is more common in developing countries, and rare among developed countries. The most common forms of liver abscess are amoebic , pyogenic , or mixed in etiology.

3. Approximately 60% are solitary and they are mainly located in the right lobe as a result of streaming pattern of portal blood flow, secondary to the fact that right lobe is supplied predominantly by the Superior Mesenteric Vein, and because most of the hepatic volume is in the right lobe. When multiple abscesses are present, pyogenic or mixed abscesses are the most probable cause.

4. Amoebic Liver Abscess Amebiasis Amebiasis is an infection caused by Entamoeba histolytica , an intestinal protozoan. Its spectrum of clinical syndromes ranges from asymptomatic colonization (90% of cases) to invasive amebiasis. Invasive amebiasis frequently presents as intestinal colitis (dysentery or diarrhea) or as extraintestinal amebiasis, in which abscesses of the liver are more commonly found than involvement of the lungs or brain.

5. Amebiasis occurs in 10% of the world’s population and is most common in tropical and subtropical regions. Amoebic liver abscess is the most common extraintestinal manifestation of amebiasis. Host factors that contribute to the severity of disease include younger age, pregnancy, malnutrition, alcoholism, glucocorticoid use, and malignancy.

6. Transmission and Pathogenesis:

7. Pathogenesis: During its life cycle, Entamoeba histolytica exists as trophozoite or cyst forms . After infection, amebic cysts pass through the GI tract and become trophozoites in the colon, where they invade the mucosa and produce typical “ flask shaped ” ulcers. The organism is carried by the portal vein circulation to the liver, where an abscess may develop. Occasionally, organisms travel beyond the liver and can establish abscesses in the lung or brain. Rupture of an amebic liver abscess into the pleural, pericardial, and peritoneal spaces can also occur.

8. Clinical features: Amebic liver abscess is 10 times as common in men as in women and is rare in children. An amebic liver abscess has acute presentation than a pyogenic liver abscess. Symptoms are present on average for 2 weeks by the time a diagnosis is made. Pain is typically localized to the RUQ which is dull or pleuritic in nature and may radiate to right shoulder but may be localized to the right chest, epigastrium . Fever is nearly universal but may be intermittent. Malaise, myalgias, and arthralgias are common. Jaundice is uncommon and signifies a poor prognosis. Pulmonary symptoms and signs may be present

9. C omplications of amoebic abscesses can include pleuroperitoneal involvement in 20 -30%, sterile effusions , intraperitoneal, intrathoracic, and pericardial rupture and hepatobronchial fistula. The diagnosis of amoebic liver abscess is based on clinical suspicion, hepatic imaging, and serologic testing. Stool examination :The organism is isolated from the stool in only 50% of patients. An amoebic abscess is commonly localized to the right hepatic lobe, close to the diaphragm. PCR-based tests to detect amebic DNA and an ELISA to detect amoebic antigens in serum are available.

10. Lab values: Leukocytosis (>15 x 10 9 cells/L) with neutrophilia, ↑ ESR, slight Anaemia, ↑ ALP, hypoalbuminaemia in 33%. Sr. antibodies to E. histolytica are detected in >90% of pts. The enzyme immunoassay (EIA) which has 99% sensitivity is also commonly used. Imaging studies are very important in the workup of pts. USG is the initial screening choice. The abscess appear as a hypoechoic round or oval lesion with well defines margins. Triphasic CT or MRI are indicated for differential diagnosis and have higher sensitivity.

11. Aspiration of an amebic abscess should be performed if the diagnosis remains uncertain. The presence of a reddish-brown pasty aspirate (“ anchovy paste ” or “ chocolate sauce ”) is typical. Aspiration also may be considered when no response to antibiotic therapy has occurred after 5 to 7 days or when an abscess in the left lobe of the liver is close to the pericardium.

12. Treatment Standard therapy consists of metronidazole , 750 mg 3 times daily by mouth or, if necessary, IV for 7 to 10 days. Tinidazole or chloroquine may be substituted for metronidazole. The response to treatment usually occurs within 96 hours. Following a course of metronidazole, addition of an oral luminal amebicide—such as iodoquinol , 650 mg 3 times daily for 20 days; diloxanide furoate , 500 mg 3 times daily for 10 days; or aminosidine (paromomycin), 25 to 35 mg/kg daily in 3 divided doses for 7 to 10 days

13. Indications for aspiration of liver abscesses are T he need to rule out a pyogenic abscess , particularly in patients with multiple lesions; T he lack of a clinical response in 3–5 days; T he threat of imminent rupture ; and T he need to prevent rupture of left-lobe abscesses into the pericardium. Percutaneous drainage may be successful even if the liver abscess has already ruptured. Surgery should be reserved for instances of bowel perforation and rupture into the pericardium.

14. PYOGENIC LIVER ABSCESS Previously, it was consequence of appendicitis complicated by pylephlebitis (portal vein inflammation) in a young patient. This presentation is uncommon today as a result of earlier diagnosis and effective antibiotic therapy. Predisposing conditions include malignancy , immunosuppression, diabetes mellitus, and previous biliary surgery or interventional endoscopy.

15. Pathogenesis: Infections of the biliary tract (e.g., cholangitis, cholecystitis) are the most common identifiable source of liver abscess. Infection may spread to the liver from the bile duct, along a penetrating vessel, or from an adjacent septic focus (including pylephlebitis ). Pyogenic liver abscess may arise as a late complication of endoscopic sphincterotomy for bile duct stones or within 3 to 6 weeks of a surgical biliary-intestinal anastomosis. Occasionally, a pyogenic liver abscess may be the presentation of a HCC or gallbladder ca or a complication of chemoembolization or percutaneous ablation of a hepatic neoplasm.

16. Microbiology Most pyogenic liver abscesses are polymicrobial. The most frequently isolated organisms are Escherichia coli and Klebsiella , Proteus , Pseudomonas , and Streptococcus species, particularly the Streptococcus milleri group. Certain virulent strains of Klebsiella pneumoniae can cause liver abscess in the absence of underlying hepatobiliary disease, often with metastatic infection.

17. Clinical features In the preantibiotic era, patients with a pyogenic liver abscess typically presented with acutely spiking fevers, pain in the RUQ, and, in many cases, shock. After the introduction of antibiotics, the presentation of pyogenic liver abscess became less acute. Today’s presentation often is insidious, particularly in older adult patients, and is characterized by malaise , low grade fever , anorexia , weight loss , and dull abdominal pain that may increase with movement. Symptoms may be present for 1 month or more before a diagnosis is made. Multiple abscesses are typical when biliary disease is the source and are associated with a more acute systemic presentation.

18. When an abscess is situated near the dome of the liver, pain may be referred to the right shoulder, or a cough resulting from diaphragmatic irritation or atelectasis may be present. Physical examination usually discloses fever, hepatomegaly, and liver tenderness, which is accentuated by movement or percussion. Splenomegaly is unusual, except with a chronic abscess. Ascites is rare, and in the absence of cholangitis, jaundice is present only late in the course of the illness.

19. Diagnosis: Blood culture specimens will identify the causative organism in at least 50% of cases. Direct cultures of aspirated fluid should be sent for both aerobic and anaerobic culture. Chest x-rays may show elevation of the right hemidiaphragm and atelectasis. USG and CT are the initial imaging modalities of choice. USG is inexpensive and accurate and can guide needle aspiration of the abscess. Culture specimens of aspirated material yield positive results in 90% of cases. Hepatic abscesses are usually hypodense on a CT and may display a rim of contrast enhancement.

20. Principles of Management of Pyogenic Liver Abscess Drain the pus Institute appropriate antibiotics, and Deal with any underlying source of infection Percutaneous drainage combined with antibiotics has become the first line and mainstay of treatment for most PLAs

21. Prevention and Treatment Pyogenic liver abscesses are best prevented by prompt treatment of acute biliary and abdominal infections and by adequate drainage of infected intra-abdominal collections under appropriate antibiotic coverage. An indwelling drainage catheter may be placed in the abscess until the cavity has resolved, particularly for lesions >5 cm in size, although intermittent needle aspiration may be as effective as continuous catheter drainage for smaller lesions. With multiple abscesses, only the largest abscess may need to be aspirated . For a small abscess, antibiotic therapy without drainage may suffice.

22. Surgical drainage of a hepatic abscess may be necessary in patients with incomplete percutaneous drainage, unresolved jaundice, renal impairment, a multiloculated abscess, or a ruptured abscess. Third-generation cephalosporin, or fluoroquinolone plus metronidazole , is to be started to cover anaerobic organisms. Alternative regimens include combinations of a beta-lactam and betalactamase inhibitor active against enteric organisms, including anaerobes. After culture results and sensitivity profiles are obtained, IV antibiotics therapy directed at the specific organism should be administered f/b oral therapy.

23. A worse prognosis is associated with a delay in diagnosis, multiple abscesses, multiple organisms cultured from blood, a fungal cause, shock, jaundice, hypoalbuminemia, a pleural effusion, an underlying biliary malignancy, multiorgan dysfunction, sepsis, or other associated medical diseases. Complications of pyogenic liver abscess include : E mpyema, P leural or pericardial effusion, P ortal or splenic vein thrombosis, R upture into the pericardium, T horacic and abdominal fistula formation, and S epsis.

24. Drainage options Percutaneous -Needle aspiration -Catheter drainage Surgical drainage -Open -Laparoscopic

25. Percutaneous Needle Aspiration Under CT or USG guidance, needle aspiration of cavity material can be performed. Needle aspiration enables -Rapid recovery of material for microbiologic and pathologic evaluation Large percentage requires second or third aspirations to achieve success.

26. Percutaneous Catheter Drainage Percutaneous drainage has become the standard of care. Should be the first intervention considered for: Large cysts diameter (>5cm) Pus is too thick to be aspirated The wall is thick and non-collapsible Left lobe abscess Medical Treatment failure

27. Advantages of Percutaneous Catheter Drainage Reduces costs, recovery time It eliminates the need for general anaesthesia This also allows for gradual, controlled drainage

28. Percutaneous Catheter Drainage A catheter is placed under ultrasonic or CT guidance via the Seldinger or trocar techniques. The catheter is flushed daily until output is less than 10mL/day or cavity collapse is documented by serial CT. Contraindications of catheter drainage: -Coagulopathy, -A difficult access path to the cavity; -Peritonitis; -A complicated, multiloculated, thick-walled abscess with viscous pus.

29. Long term Monitoring Weekly serial CT or US examinations to document adequate drainage of the abscess cavity. Maintain drains until the output is less than 20mL/day. Monitor fever curves. -Persistent fever after 2 weeks of therapy may indicate the need for more aggressive drainage. For pts with an underlying malignancy, definitive treatment, such as surgical removal of the mass, should be pursued, if possible. Patients on prolonged parenteral antibiotics monitoring of RFT, and Total counts and CRP is needed.

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