Liver abscess in children

An overview on liver abscess in children. Causes, diagnosis and management.

1. LIVER ABSCESS Dr Joyce Mwatonoka 3 rd Year Resident Pediatrics and Child Health March 2021

2. Introduction Pyogenic liver abscesses are rare in children 50% are seen in children < 6yrs old Solitary liver abscesses (70% of cases) in the Right lobe of the liver (75% of cases) are more common than multiple abscesses or solitary Left lobe abscesses

3. Epidemiology Liver abscesses are the most common type of visceral abscess Incidence 10/100,000. M>F I n a report of 540 cases of intraabdominal abscesses pyogenic liver abscesses accounted for 48% Intra-abdominal abscesses. Altemeier WA, Culbertson WR, Fullen WD, Shook CD Am J Surg. 1973;125(1):70. 

4. Risk factors DM U nderlying hepatobiliary or pancreatic disease L iver transplant R egular use of proton-pump inhibitors (increase gastric Ph, impair defense mechanisms against ingested pathogens – Klebsiella pneumoniae ) Immunosuppression Geographical location ( eg ; East Asia)

5. Causes and pathogenesis V ia the portal circulation in cases of omphalitis , portal vein pylephlebitis , intraabdominal infection, or abscess secondary to appendicitis or inflammatory bowel disease A primary bacteremia (sepsis, endocarditis ) A scending cholangitis associated with biliary tract obstruction caused by gallstones or sclerosing cholangitis or secondary to choledochal cysts C ontiguous infection ( subphrenic abscess) or penetrating trauma;

6. Cont… Very rarely, liver abscesses occur after percutaneous liver biopsy I n neonates ; association with sepsis, umbilical vein associated infection, or cannulation In adults liver transplantation is a significant risk factor (unknown in pediatric)

7. Cont… Children with chronic granulomatous disease, Job syndrome, or cancer are also at increased risk for a hepatic abscess

8. M ost common pathogenic organisms; Staphylococcus aureus Streptococcus spp Escherichia coli Klebsiella pneumoniae Salmonella, and A naerobic organisms Entamoeba histolytica or Toxocara canis –associated liver in developing countries or in highly endemic areas

9. Cont… If E. histolytica is recovered from the stool, distinguish it from Entamoeba dispar , which looks similar but is nonpathogenic ( antiamebic antibodies) Multiple microabscesses are most commonly secondary to bacteremia , candidemia , or cat scratch disease ( Bartonella henselae  infection; one of the commonest causes of FUO in children) Polymicrobial involvement is seen in approximately 50%

10. Clinical presentation H igh index of suspicion for those with risk factors Dx can be challenging and is often delayed Signs and sxs are nonspecific and can include fever , abdominal pain , chills, night sweats, malaise, fatigue, nausea, with RUQ tenderness, and hepatomegaly J aundice is uncommon

11. Investigations AST, and more often ALP are elevated ESR is high FBP; Leukocytosis is common B lood cultures are positive in 50% of pts

12. Cont… CXR might show elevation of the Rt hemidiaphragm or a right pleural effusion Ultrasound (hypo- to hyperechoic , septations ) or CT ( hypoattenuation )can confirm dx (sensitivity 85% and 95% respectively) MRI Diagnosis of pyogenic liver abscess by abdominal ultrasonography in the emergency department. Lin AC, Yeh DY, Hsu YH, Wu CC, Chang H, Jang TN, Huang CH  Emerg Med J. 2009;26(4):273

13. Ultrasound (Lt) and CT scan images

14. Cont… Enzyme-linked immunosorbent assay testing for E. histolytica Gal/ GalNAc ( galactose /N-acetyl-d- galactosamine ) lectin in serum is usually positive with amebiasis

15. Differential diagnoses Hepatitis of any cause ( eg , viral, drug induced) Primary or secondary liver tumors Right lower lobe pneumonia Acute cholangitis Acute cholecystitis Tuberculous liver abscesses  Hepatic hydatid cysts ( Echinococcus ) Hepatosplenic candidiasis , with microabscesses

16. Treatment Treatment requires percutaneous ultrasound- or CT-guided needle aspiration/catheter drainage and less often open surgical drainage, particularly if multiple or large abscesses are present Some place a drain and leave it in until the abscess wall collapses, others just do single or repeated aspirations

17. Drainage   Both therapeutic and diagnostic CT-guided or ultrasound-guided percutaneous drainage (with needle aspiration only or with catheter placement) Open surgical drainage Laparoscopic drainage Drainage by endoscopic retrograde cholangiopancreatography (ERCP)

18. Cont… Single, unilocular abscesses with a diameter ≤5 cm; Percutaneous drainage with either catheter placement or needle aspiration Single, unilocular abscesses with diameter >5 cm; catheter preferred

19. Cont… Multiple or multiloculated abscesses; decision made on an individual basis by a multidisciplinary team taking into account the number, size, and accessibility of the abscess(es), the experience of the surgeons and radiologists Percutaneous needle aspiration versus catheter drainage in the management of liver abscess: a systematic review and meta-analysis. Cai YL, et al. HPB (Oxford). 2015;17(3):195. Epub 2014 Sep 10

20. Antibiotic therapy Treatment recommendations are based upon the probable source of infection and should be guided by local bacterial resistance patterns, if known The empiric regimen should cover streptococci, enteric gram-negative bacilli, and anaerobes. In addition  E. histolytica (unless involvement unlikely)

21. Cont… A third or later generation cephalosporin ( eg ,  ceftriaxone ) plus  metronidazole A beta- lactam -beta- lactamase inhibitor combination ( eg ,  piperacillin-tazobactam ) with or without  metronidazole  (the metronidazole for  E. histolytica  coverage) Ampicillin  plus  gentamicin  plus  metronidazole

22. Cont… Alternative regimens include: A fluoroquinolone with  metronidazole A carbapenem with or without  metronidazole  (the metronidazole would be to provide  E. histolytica  coverage) If the pt is in septic shock or if  S. aureus  is a concern ( eg , indwelling catheter or injection drug use), add  vancomycin

23. Cont… Regardless of whether a causative organism has been identified, antibiotic therapy is recommended for 4-6wks If no culture results, empiric oral antibiotic choices include  amoxicillin- clavulanate alone, or a fluoroquinolone plus  metronidazole A pilot study of oral fleroxacin once daily compared with conventional therapy in patients with pyogenic liver abscess.AUChen YW, Chen YS, Lee SS, Yen MY, Wann SR, Lin HH, Huang WK, Liu YC SOJ Microbiol Immunol Infect. 2002;35(3):179

24. Follow-up Should only be done in the setting of persistent clinical symptoms or if drainage is not proceeding as expected Radiological abnormalities resolve much more slowly (16 – 22 weeks) than clinical and biochemical markers Long-term follow-up of pyogenic liver abscess by ultrasound. K C S, Sharma D  Eur J Radiol . 2010 Apr;74(1):195-8. Epub 2009 Feb 12.

25. Prognosis Mortality has decreased significantly with early dx and initiation of appropriate therapy The mortality rate in developed countries ranges from 2 to 12% Independent risk factors for mortality include need for open surgical drainage , the presence of malignancy , and the presence of anaerobic infection

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