Health

1. PYOGENIC LIVER ABSCESSES

2. OUTLINE
 Introduction
 Etiology of pyogenic liver abscess
 Clinical Features of pyogenic liver abscess
 Diagnosis of pyogenic liver abscess
 Treatment of pyogenic liver abscess
 Parasitic Liver Abscess

3. Pyogenic Liver Abscesses

4. INTRODUCTION
 The liver parenchyma is constantly exposed to a
low level of enteric bacteria through the portal blood
flow
 However, liver infections are rare.
 The liver is the largest repository of the
reticuloendothelial system and is therefore able to
cope with this constant barrage.
 When the inoculum exceeds the capacity for
control, infection and abscess occur.
 Liver abscess can be ascribed to two categories:
pyogenic or parasitic

5. INTRODUCTION
 Pyogenic liver abscesses have been well known for
over 100 years and were a common cause of
morbidity and mortality in patients with untreated
appendicitis and pylephlebitis
 Liver abscesses may be solitary or multiple

6. ETIOLOGY
 In the past, appendicitis with rupture and
subsequent spread of infection was the most
common source for a liver abscess.
 Currently, associated disease of the biliary tract is
most common.
 Pylephlebitis (suppurative thrombosis of the portal
vein), usually arising from infection in the pelvis but
sometimes from infection elsewhere in the
peritoneal cavity, is another common source for
bacterial seeding of the liver

8. ETIOLOGY
 Currently, the most common etiologies of pyogenic liver
abscesses include:
 Biliary tract manipulation
 Diverticular disease
 Inflammatory bowel disease and
 Systemic infections such as bacterial endocarditis.
 Rarely, ERCP for ascending cholangitis or the
management of biliary strictures may result in liver
abscess.
 Patients with contrast material injected proximal to
undrained strictures are at high risk.

9. ETIOLOGY
 Organisms recovered from liver abscesses vary
with the source.
 Biliary focus
 Enteric gram-negative aerobic bacilli and enterococci
are common isolates
 Unless previous surgery has been performed,
anaerobes are not generally involved in liver abscesses
arising from biliary infections
 Monomicrobial abscesses are found in approximately
40% of patients, an additional 40% are polymicrobial,
while the remaining cases are culture negative

10. ETIOLOGY
 Pelvic and Intraperitonial sources
 In contrast, here, a mixed flora including both aerobic
and anaerobic species is common; B. fragilis is the
species most frequently isolated
 Hematogenous
 With hematogenous spread of infection, usually only a
single organism is encountered; this species may be S.
aureus or a streptococcal species such as S. milleri

11. ETIOLOGY
 Results of cultures obtained from drain sites are not
reliable for defining the etiology of infections.
 Liver abscesses may also be caused by Candida
spp.; such abscesses usually follow fungemia in
patients receiving chemotherapy for cancer and
often present when PMNs return after a period of
neutropenia.

13. CLINICAL FEATURES
 Early symptoms during the onset of a pyogenic liver
abscess are non-specific and include malaise, nausea,
anorexia and weight loss, headaches, myalgia, and
arthralgia in most of the cases.
 These prodromal symptoms may be present for many
weeks before the appearance of more specific
symptoms, such as fever, chills and abdominal pain,
although the pain is not always localized to the right
upper quadrant
 Fever is the most common presenting sign of liver
abscess

14. CLINICAL FEATURES
 Some patients, particularly those with associated
disease of the biliary tract, have symptoms and
signs localized to the right upper quadrant,
including pain, guarding, punch tenderness, and
even rebound tenderness
 Nonspecific symptoms, such as chills, anorexia,
weight loss, nausea, and vomiting, may also
develop

15. CLINICAL FEATURES
 Only 50% of patients with liver abscesses, however,
have hepatomegaly, right-upper-quadrant
tenderness, or jaundice;
 Thus, one-half of patients have no symptoms or
signs to direct attention to the liver.
 Fever of unknown origin (FUO) may be the only
manifestation of liver abscess, especially in the
elderly
 Diagnostic studies of the abdomen, especially the right
upper quadrant, should be a part of any FUO workup

16. CLINICAL FEATURES
 An abscess adjacent to the diaphragm may cause
pleuritic type pain, cough and dyspnea, and when
this presentation is associated with the above-
mentioned non-specific symptoms, it can cause
diagnostic difficulty
 Although uncommon, some patients present with
peritonitis after free rupture of an abscess into the
peritoneal cavity

17. LABORATORY FEATURES
 The single most reliable laboratory finding is an elevated
serum concentration of alkaline phosphatase, which is
documented in 70% of patients with liver abscesses.
 Other tests of liver function may yield normal results, but
50% of patients have elevated serum levels of bilirubin,
and 48% have elevated concentrations of aspartate
aminotransferase
 Other laboratory findings include leukocytosis in 77% of
patients, anemia (usually normochromic, normocytic) in
50%, and hypoalbuminemia in 33%.

18. IMAGING
 A liver abscess is sometimes suggested by chest
radiography, especially if a new elevation of the
right hemidiaphragm is seen;
 Other suggestive findings include a right basilar
infiltrate and a right pleural effusion

19. IMAGING
 Imaging studies are the most reliable methods for
diagnosing liver abscesses.
 These studies include ultrasonography, CT, indium-
labeled WBC or gallium scan, and MRI.

20.  Ultrasound
 The imaging modality used in the initial evaluation.
 The appearance on USG varies according to the stage of
evolution of the abscess
 Initially the abscess is hyperechoic and indistinct, but with
maturation and pus formation, it becomes hypoechoic with a
distinct margin.
 When the pus is very thick, a fluid-containing lesion may be
confused with a solid lesion on USG.
 USG has a sensitivity of 75% to 95%, but has difficulty in
detecting an abscess high in the dome of the right hemiliver
and especially multiple small abscesses.
 By showing gallstones, dilated bile ducts, and hepatolithiasis,
USG has the advantage of imaging underlying biliary tract
pathology

21.  CT
 More accurate than ultrasound in the differentiation of
pyogenic liver abscess from other liver lesions and is
reported to have a sensitivity of approximately 95%
 The portal venous phase using intravenous contrast
material gives the best differentiation between the liver
and the abscess, with the periphery of the abscess
having contrast enhancement as opposed to non-
enhancement of the central portion
 Magnetic resonance imaging (MRI) does not seem
to have any advantage over CT or USG.

24. TREATMENT
 The mortality rate was appreciable despite
treatment, averaging 15%.
 Principles include
 Drain the pus
 Institute appropriate antibiotics, and
 Deal with any underlying source of infection, if present.

25. TREATMENT- DRAINAGE
 Drainage techniques include
 CT-guided or ultrasound-guided percutaneous drainage
(with or without catheter placement),
 Surgical drainage, or
 Drainage by endoscopic retrograde
cholangiopancreatography (ERCP)
 For single abscesses with a diameter ≤5 cm, either
percutaneous catheter drainage or needle
aspiration is acceptable.

26. TREATMENT- PERCUTANEOUS DRAINAGE
 In patients with a solitary dominant abscess,
percutaneous aspiration with evaluation by Gram's
stain and culture is essential to direct further
antimicrobial and drainage therapy.
 In patients with solitary abscesses, aspiration alone
may be sufficient if the abscess can be significantly
drained.
 The placement of a percutaneous drainage catheter
at the time of aspiration is beneficial for patients
with a complex abscess or an abscess containing
particularly thick fluid.

27. TREATMENT- PERCUTANEOUS DRAINAGE
 Percutaneous needle aspiration group has a high
success rate and a shorter hospital stay, but a large
percentage requires second or third aspirations to
achieve success.
 When this fails, catheter drainage should be
performed.

28. TREATMENT- PERCUTANEOUS DRAINAGE
 Primary treatment by percutaneous catheter
drainage is performed when:
 The pus is too thick to be aspirated
 The abscess is greater than 5 cm in diameter
 The wall is thick and non-collapsible
 The abscess is multi-loculated
 The use of catheter drainage is not precluded by
the presence of multiple abscess cavities, but this
does necessitate the placement of several
catheters

29. TREATMENT- PERCUTANEOUS DRAINAGE
 Although highly successful, percutaneous drainage
procedures fail in approximately 10% cases.
 Incomplete or unsuccessful drainage may result from:
 Catheter too small to drain the thick pus,
 Position of catheter not conducive to adequate drainage,
 Catheter removed prematurely
 Thick fibrous encasing wall of pyogenic liver abscess that is
unable to collapse.
 An abscess with biliary communication has been
reported to be treated as effectively by percutaneous
catheter drainage as a non-communicating abscess,
although the continuous output of bile leads to a
prolonged period of abscess drainage

30. TREATMENT- PERCUTANEOUS DRAINAGE
 Occasionally patients presenting with multiple small
abscesses are not amenable to percutaneous
sampling.
 Under such circumstances, laparoscopic evaluation
of the liver, including Intraoperative ultrasonography
(IOUS) and a focused biopsy, can be beneficial.

31. TREATMENT- DRAINAGE
 Drainage catheters should remain in place until
drainage is minimal (usually up to seven days).
Repeat needle aspiration may be required in up to
half of cases if a catheter is not left in situ
 For percutaneous management of single abscesses
with diameter >5 cm, catheter drainage is preferred
over needle aspiration
 For single abscesses with diameter >5 cm, some
favor surgical intervention over percutaneous
drainage

32. TREATMENT- DRAINAGE
 When percutaneous drainage was compared with
open surgical drainage,
 The average length of hospital stay for the former was
almost twice that for the latter
 Both the time required for fever to resolve and the
mortality rate were the same for the two procedures.

33. TREATMENT- SURGICAL DRAINAGE
 Several factors predict the failure of percutaneous
drainage and therefore may favor primary surgical
intervention.
 These factors include the presence of:
 Multiple, sizable abscesses
 Viscous abscess contents that tend to plug the catheter
 Associated disease (e.g., disease of the biliary tract) requiring
surgery or
 The lack of a clinical response to percutaneous drainage in 4–7
days.

34. TREATMENT- SURGICAL DRAINAGE
 Surgical drainage is also appropriate in the following
circumstances:
 Multiple abscesses
 Loculated abscesses
 Abscesses with viscous contents obstructing the drainage
catheter
 Underlying disease requiring primary surgical management
Note: Multiple or loculated abscesses may be
successfully managed by percutaneous drainage

35. TREATMENT- SURGICAL DRAINAGE
 Can surgery be indicated from the outset?
 Yes
 The only indication of primary surgical treatment of
Pyogenic Liver Abscess is in patients with:
 Initial presentation with intraperitoneal rupture or
 Multiple abscesses above an obstructed system that cannot be
negotiated by non-operative means

36. TREATMENT- SURGICAL DRAINAGE
 What kind of procedure?
 The traditional principles of surgery are:
 To perform needle aspiration before
 Blunt puncture,
 Finger explorations to break down loculations,
 Insertion of a large bore drainage tube for adequate drainage
and to maximize dependent drainage.
 Postoperative irrigation and suction of the cavity via the
drainage tube is usually advantageous.
 There have been isolated references to the use of
hepatic resection in the treatment of PLAs

37. TREATMENT- ANTIBIOTICS
 The drugs used for empirical therapy include the
same ones used in intraabdominal sepsis and
secondary bacterial peritonitis.
 Usually, blood cultures and a diagnostic aspirate of
abscess contents should be obtained before the
initiation of empirical therapy, with antibiotic choices
adjusted when the results of Gram's staining and
culture become available

38. TREATMENT- ANTIBIOTICS
 Empiric Antibiotic Rx: First Choice
Monotherapy with a beta-lactam/beta-lactamase inhibitor:
Ampicillin-sulbactam• 3 g IV every six hours
Piperacillin-tazobactamΔ 3.375 or 4.5 g IV every six
hours
Ticarcillin-clavulanate 3.1 g IV every four hours
Combination third generation cephalosporin PLUS
metronidazole:
Ceftriaxone plus
1 g IV every 24 hours or 2 g IV
every 12 hours for CNS
infections
Metronidazole 500 mg IV every eight hours

39. TREATMENT- ANTIBIOTICS
 Empiric Antibiotic Rx: Alternatives
Combination fluoroquinolone◊ PLUS metronidazole:
Ciprofloxacin or 400 mg IV every 12 hours
Levofloxacin plus 500 or 750 mg IV once daily
Metronidazole 500 mg IV every eight hours
Monotherapy with a carbapenem
Imipenem-cilastatin 500 mg IV every six hours
Meropenem 1 g IV every eight hours
Doripenem 500 mg IV every eight hours
Ertapenem¥ 1 g once daily

40. TREATMENT- ANTIBIOTICS
 Antibiotic therapy should be continued for four to six
weeks.
 Patients who have had a good response to
initial drainage should be treated with two to
four weeks of parenteral therapy, while patients
with incomplete drainage should receive four to
six weeks of parenteral therapy.
 The remainder of the course can then be completed
with oral therapy tailored to culture results

41. TREATMENT- ANTIBIOTICS
 In patients with multiple PLAs that are too small to
drain, antibiotics may be the only treatment
possible.
 In addition, efforts must be made to identify any
underlying biliary obstruction, which needs to be
overcome for the antibiotic therapy to succeed

42. TREATMENT- ANTIBIOTICS
 Treatment of candidal liver abscesses often entails
initial administration of amphotericin B or liposomal
amphotericin, with subsequent fluconazole therapy.
 In some cases, therapy with fluconazole alone (6
mg/kg daily) may be used
 e.g., in clinically stable patients whose infecting isolate
is susceptible to this drug

43. IN SHORT
 There is no single therapy that cures all cases.
 Antibiotics combined with percutaneous aspiration
(which may need to be repeated) or PCD is
successful in 90% of patients

44. PROGNOSIS
 With modern treatments, the prognosis depends more
on the underlying etiology and co-morbid factors than
the pyogenic liver abscess itself, although delay in
presentation and diagnosis contributes to a poor
outcome.
 The risk factors most commonly associated with
mortality include:
 Septic shock,
 Clinical jaundice
 Coagulopathy
 Leukocytosis
 Hypoalbuminemia
 Multiple abscesses
 Intraperitoneal rupture
 Malignancy (more in hepatopancreatobiliary malignancy than
other malignant diseases)

45. Amebic Liver Abscess

46. C/F: COLITIS
 Most: asymptomatic
 Symptoms appear 2–6 weeks after ingestion of the
cyst form of the parasite
 Diarrhea (classically heme-positive) and lower
abdominal pain are the most common symptoms
 Severe dysentery, with 10–12 small-volume, blood-
and mucus-containing stools daily, may develop,
but only 40% of patients are febrile

47. C/F: COLITIS
 Fulminant amebic colitis
 More profuse diarrhea, severe abdominal pain
(including peritoneal signs), fever, and pronounced
leukocytosis
 Rare
 Disproportionately affecting young children, pregnant
women, individuals being treated with glucocorticoids,
and possibly individuals with diabetes or alcoholism
 Intestinal perforation occurs in >75% of patients with
this fulminant form of disease.
 Mortality rates from fulminant amebic colitis exceed
40% in some series

48. C/F: LIVER ABSCESS
 Mortality rates are now 1–3%
 Disease begins when E. histolytica trophozoites
penetrate through the colonic mucosa, travel
through the portal circulation, and reach the liver.
 Approximately 20% have a past history of
dysentery and another 10% history of diarrhoea or
dysentery at the time of diagnosis

49. C/F: LIVER ABSCESS
 Classic findings: right-upper-quadrant pain, fever,
and hepatic tenderness.
 Usually acute, with symptoms lasting <10 days.
 A more chronic presentation, with weight loss and
anorexia as prominent accompanying features,
does occur

50. C/F: OTHER EXTRAINTESTINAL CXNS
 Right-sided pleural effusions and atelectasis
 Require no treatment
 Pleuropulmonary amebiasis
 Rupture of the abscess through the diaphragm in about
10% of patients
 Hepatobronchial fistula
 Patients can cough up the contents of the liver
abscess—copious amounts of brown sputum that may
contain E. histolytica trophozoites.

51. C/F: OTHER EXTRAINTESTINAL CXNS
 Rupture in to the peritonium
 About 1-3% of patients
 Rupture into the pericardium
 Cerebral abscesses
 <0.1% of cases of amebic liver abscess
 associated with the sudden onset of headache,
vomiting, seizures, and mental status changes and a
high mortality rate

52. C/F: OTHER EXTRAINTESTINAL CXNS
 Rarely
 Cutaneous amebiasis (which usually involves the anal
and perianal regions)
 Genital disease (including rectovaginal fistulas),
 Urinary tract lesions are rare but reported complications
of amebiasis.

53.  Risk Factors for ALA are:
 Alcoholism
 Malignancy
 HIV infection
 Malnutrition
 Corticosteroid use
 Disorders of cell mediated immunity
 Homosexual activity
 Recent travel to tropics

54. DIAGNOSIS
 Stool microscopy
 Unable to differentiate between E. histolytica and other
Entamoeba species, such as E. dispar and E.
moshkovskii
 Examination of three stool samples improves sensitivity
 Presence of amebic trophozoites containing red blood
cells in a diarrheal stool is highly suggestive of E.
histolytica infection

55. DIAGNOSIS
 Serology
 Less expensive and more easily performed
 Greater sensitivity than microscopy
 Ability to detect E. histolytica specifically represent
significant advantages over microscopy.

56. DIAGNOSIS
 Microscopy combined with serologic testing:
standard diagnostic modality
 Stool culture: more a research tool
 PCR

57. DX: AMEBIC LIVER ABSCESS
 CT or U/S detection of one or more space-
occupying lesions in the liver and a positive
serologic test for antibodies to E. histolytica
antigens.
 Classically described as single, large, and located
in the right lobe of the liver
 The incidence of ALA of the left lobe ranges from 5% to
21%

58. DX: AMEBIC LIVER ABSCESS
 The liver abscess has a thin capsular wall with a
necrotic centre composed of a thick fluid.
 Typically, abscess fluid is odourless, resembling
‘chocolate syrup’ or anchovy paste’ in half, and
bacteriologically sterile, although secondary
bacterial invasion may occur (in 15 to 20%).
 When a patient has a space-occupying lesion of the
liver, a positive amebic serology is highly sensitive
(>94%) and highly specific (>95%) for the diagnosis
of amebic liver abscess

59.  On aspiration, the amoebae are sparse in necrotic
material from the centre of the abscess, but are
more abundant on the marginal walls and are
therefore more commonly found in the last portion
of aspirated material.

60. TREATMENT
 Four groups of treatment modalities are effective:
1. Drug therapy only
2. Ultrasound-guided aspiration and drug
3. Percutaneous catheter drainage and drug
4. Laparatomy, drainage and drug

61. TREATMENT- DRUG THERAPY
 Criteria for medical management
 All non-complicated abscess
 No features of rupture / impending rupture
 No compression effect
 To date, E. histolytica has not demonstrated
resistance to any of the commonly used agents—a
situation that greatly simplifies treatment.
 Tinidazole appears to be better tolerated and
slightly more effective than metronidazole for
amebic colitis and amebic liver abscess.

62. TREATMENT- DRUG THERAPY
 Treatment with tinidazole or metronidazole in the
same doses used for amebic colitis is almost
always successful.
 More than 90% of patients respond with a decrease
in abdominal pain and fever within 72 h of the
initiation of therapy.
 Drainage of amebic liver abscesses is rarely
needed

64. TREATMENT- DRUG THERAPY
 Neither metronidazole nor tinidazole reaches high
levels in the gut lumen;
 Therefore, patients with amebic colitis or amebic liver
abscess should also receive treatment with a luminal
agent (paromomycin or iodoquinol) to ensure
eradication of the infection .
 Paromomycin is the preferred agent. (see below)

65. TREATMENT- DRUG THERAPY

66. TREATMENT- ASPIRATION
 Routine aspiration is not indicated for diagnosis or
treatment purposes
 Aspiration should be reserved
 Pyogenic abscess or a bacterial superinfection is
suspected
 Left lobe abscess
 Seronegative abscess
 Failure to respond to tinidazole or metronidazole (i.e.,
those who have persistent fever or abdominal pain after
4 days of treatment)
 Large liver abscesses in the left lobe (because of the
risk of rupture into the pericardium)
 Large abscesses and accelerated clinical course raise
concerns about imminent rupture.

67. TREATMENT- ASPIRATION
 In contrast, aspiration and/or percutaneous catheter
drainage improves outcomes in patients with
pleuropulmonary amebiasis and empyema
 Percutaneous catheter or surgical drainage is
absolutely indicated for cases of amebic
pericarditis.

68. TREATMENT- ASPIRATION
 Rupture into the peritoneum is generally managed
conservatively, with medical therapy and
percutaneous catheter drainage of fluid collections
as needed

69. TREATMENT- SURGERY
 Open surgical drainage is rarely indicated and may be
required in the setting of:
 Large abscess with a poor yield on needle aspiration or
percutaneous drainage
 Clinical deterioration despite attempted needle aspiration
 Complicated ALA (like ruptured abscess in peritoneal cavity
with features of peritonitis)
 Complicated ALA (ruptured in the pleural cavity / pericardial
cavity/ adjacent viscera)
 Surgical mortality is, however, very high. Hence, in
clinical practice, it is only used when the cavity has
ruptured into adjacent viscera or body cavities.

70. OUTCOME
 After clinical cure, patients show few symptoms and
sonographic follow up demonstrates evidence of
persistent hypoechoic lesion.
 The mean time for the disappearance of the
sonographic abnormality is 6-9 months.
 Relapses are very uncommon and the sonographic
abnormality does not warrant continued therapy
 The mortality rate has been estimated to be around
0.2-2.0% in adults and up to 26% in children.1

71. PROGNOSTIC MARKERS
 Independent risk factors for mortality in ALA are:
 Bilirubin level > 3.5 mg/dl
 Encephalopathy,
 Volume of abscess cavity
 Hypoalbuminaemia (serum albumin <2g/dl)
 The duration of symptom and the type of treatment
does not influence mortality

72. THANK YOU!