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INFECTIONS OF LIVER

July 4, 2024

Pyogenic Liver Abscess (PLA) Overview

MCQ:

  • Most common cause of Pyogenic Liver Abscess is:

    • a) Appendicitis
    • b) Diverticulitis
    • c) Choledocholithiasis (Correct Answer)
    • d) None

    Explanation:

    • Earlier: Appendicitis and diverticulitis were the most common causes.
    • Now: Biliary etiology is the leading cause, primarily due to Choledocholithiasis (associated with ascending cholangitis).
    • Regional Differences:
      • East: Commonly caused by strictures.
      • West: Commonly associated with biliary malignancy (as noted in Blumgart).
      • Given a choice between CBD stones and Malignancy, although malignancy is less common, it is highlighted in certain references.

Other Causes:

  • Portal pyemia: Due to appendicitis or diverticulitis.
  • Systemic sepsis: Causes microabscesses.
  • Gastric cancer and colorectal neoplasm.
  • Inflammatory abdominal pathology is no longer a common cause.
  • Biliary neoplasm is the most common cause in the West.
  • Hilar cholangiocarcinoma.
  • East: Benign diseases like stones, strictures, or recurrent pyogenic cholangitis (RPC).

Clinical Features:

  • Leukocytosis: Seen in 75% of cases.
  • Jaundice: Seen in 50% of cases.
  • Ultrasound (USG):
    • Hypoechoic lesions.
    • Check the patency of the portal vein.
    • Identify biliary etiology.
    • Single Abscess: Often cryptogenic.
    • Multiple Abscesses: Often biliary in origin.
  • Most Common Location: Right lobe of the liver.
  • CT Scan: Shows a target sign.
  • Most Common Clinical Symptoms:
    • Pain abdomen.
    • Fever.
    • Jaundice is often seen.

Etiology:

  • Most Common: Polymicrobial infection.
  • Most Common Cause of Multiple Microabscesses:
    • Monomicrobial infections, usually due to systemic (hematogenous) transmission.
    • Staphylococcal and Streptococci are common pathogens.
  • Most Common Anaerobe: Bacteroides.
  • Most Common in Children: Staphylococcal infections.
  • Klebsiella pneumoniae: Most common pathogen in cryptogenic PLA in Asian populations.
  • Escherichia coli: Most common pathogen in Western countries.

Treatment:

  • Drainage + Antibiotics:
    • Drainage Options:
      • Aspiration: Suitable for small abscesses (<5 cm), usually a single-time aspiration.
      • Percutaneous Catheter Drainage (PCD): For larger abscesses.
    • Antibiotics: Administered for a minimum of 2 weeks and up to 4 weeks (oral or IV).

Amoebic Liver Abscess (ALA) Overview

Key points:

  • E. histolytica: Most common cause of invasive amoebiasis, particularly in homosexual men.
  • E. dispar: Resembles E. histolytica but does not cause invasive infection.
  • Right lobe: Most common site for ALA.
  • Simultaneous infection of both amoebic colitis and liver abscess is rare.
  • Anchovy sauce appearance: The pus is sterile, with no active trophozoites.
  • Wall of ALA: Ill-defined with a poor fibrotic response.
  • Glisson's capsule: Resistant to ALA.
  • Most E. histolytica infections are asymptomatic or present as mild non-invasive disease.
  • Active diarrhea: Occurs in less than 30% of cases.
  • Stool culture: Positive in more than 75% of cases.
  • Concomitant liver abscess: Seen in only 1/3rd of amoebic colitis cases.
  • Jaundice:
    • Often seen in Pyogenic Liver Abscess (PLA) but not commonly in ALA (according to Sabiston).
  • Most common lab abnormality: Prothrombin Time (PT)/INR.
  • Other manifestations: Basal atelectasis and, rarely, encephalopathy.

Diagnosis & Management

  • Ultrasound (USG): Hypoechoic, well-defined lesion, typically in the right lobe.
  • Resolution time:
    • Mean resolution time is 7 months.
    • Complete resolution may take up to 2 years.
  • Amoebic serology: 95% specific for diagnosis.
  • First-line treatment (DOC): Metronidazole.
    • Dose: 500-750 mg orally, three times daily for 7-10 days.
    • Contraindication: Should not be used in the first trimester of pregnancy as it crosses the placenta.
  • Luminal agents: Should be added after treatment with Metronidazole.
    • Options include Paromomycin, Iodoquinol, or Diloxanide Furoate.
    • Cure rate: 85%.
  • Dihydroemetine:
    • Effective against trophozoites.
    • Side effects: Hypotension, tachycardia, QT prolongation.
    • Used in hepatopulmonary amebiasis.

Indications for Therapeutic Aspiration

  • Pregnancy.
  • Inconclusive serology.
  • Large abscess:
    • >10 cm in general.
    • >5 cm if located in the left lobe (due to risk of rupture, as mentioned in Sabiston).
  • Symptoms persisting after 1 week of therapy.

MCQ: Treatment of a 5 cm ALA:

  • Answer: Metronidazole for 10 days (no need for aspiration/drainage).
  • If the patient does not respond within 3 days, consider the possibility of a Pyogenic Liver Abscess (PLA).

Complications

  • Most common complication: Rupture.

Amebic vs Pyogenic Liver abscess

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Hydatid Cyst

  • Larval Stage
    • Metacestode of Echinococcus granulosus
  • Species and Conditions
    • E granulosus = Liver and lungs
    • Echinococcus multilocularis: Alveolar echinococcosis = Infiltration / mets
    • Echinococcus vogeli
    • Echinococcus oligarthus: Polycystic echinococcosis = peripheral = primarily muscles
  • Hosts
    • Definitive Host: Dogs
    • Intermediate Hosts: Sheep
    • Accidental Host: Humans
  • Common Organs Affected
    • Most common organ: Liver > Lung
    • Most common lobe: Right lobe

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Hydatid Cyst Structure

  • Pericyst
    • Definition: Host reaction to the cyst
    • Also Known As: Adventitial layer
  • Ectocyst
    • Definition: Laminated membrane
    • Characteristics: Acellular layer, physiological barrier
  • Endocyst
    • Definition: Germinal layer
    • Characteristics: Germinative layer
    • if it is present we have to treat the case and if the cyst is calcified endocyst is not present
    • this has to be removed during cyst deroofing

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Hydatid Cyst Complications

  • Compressive Effect
    • Symptoms: Jaundice, Budd-Chiari syndrome
  • Infection
    • Prevalence: ~10%
  • Intrabiliary Rupture
    • Frequency: Most common complication (40-45%)
    • Communication: 90% have some communication
    • Minor Communication: <5 mm
    • Major Communication is >5mm
    • Symptoms: Biliary colic, jaundice, urticaria

Risk Factors for Cystobiliary Communication

  • Size: > 10 cm
  • Location: Near hilum
  • Gharbi Type: IV
  • Pericystic Wall: Fibrotic or calcified
  • Number of Cysts: > 1
  • Lab Findings: Leukocytosis, eosinophilia, jaundice, elevated ALP and GGT

Diagnostic Investigations for Cystobiliary Communication

  • If CBC is Present
    • Ultrasound: Snowstorm pattern
    • MRI: Filling defect on T2
    • Intracystic Findings: Fat, air, or air-fluid levels
    • Preferred Diagnosis Method: MRI > ERCP

Treatment of Cystobiliary Communication (CBC)

  • Preoperative Management
    • Conditions: Jaundice, cholangitis
    • Procedure: Endoscopic Retrograde Cholangiopancreatography (ERCP)
  • Intraoperative Management
    • Communication < 5 mm
      • Treatment: Suture
      • Additional Option: Suture + biliary decompression (transcystic or CBD)
    • Communication > 5 mm
      • Treatment Options:
        • Hepaticojejunostomy (HJ)
        • Hepatectomy (if atrophy is present)
        • Roux-en-Y Hepaticojejunostomy (HJ)

Additional Complications of Hydatid Cyst

  • Intraperitoneal Rupture
    • Cause: Intracystic pressure > 50 cm H₂O
    • Result: Secondary echinococcosis
  • Intrathoracic Rupture
    • Complications:
      • Bilio-bronchial fistula
      • Bilioptysis
  • Cutaneous Fistula
    • Frequency: Extremely rare
    • Complications:
      • Fistulization into Inferior Vena Cava (IVC)
      • Anaphylactic shock

Diagnosis of Hydatid Cyst

  • Cornerstone of Diagnosis
    • Imaging Techniques: Ultrasound (USG), Computed Tomography (CT), Magnetic Resonance Imaging (MRI)
  • Hydatid Serology
    • Prevalence: 30-40% may have no antibody
    • Antigen Detection: 5 Antigen B
    • Tests:
      • Immunoelectrophoresis (IEP): Post-treatment follow-up
      • Enzyme-Linked Immunosorbent Assay (ELISA): Quantitative detection
      • DNA Detection

Imaging Techniques

  • Ultrasound:
    • Most Characteristic Sign: Daughter cyst (cyst within cyst) - Cartwheel or honeycomb cyst
    • Other Signs: Hydatid sand, wall calcification, Water lily sign (separation of germinative membrane)

GHARBI CLASSIFICATION Vs WHO

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  • MRI
    • Advantages: Superior to CT in demonstrating internal composition of cyst and biliary involvement
    • Techniques:
      • T2 Weighted MRI: Best for demonstrating floating membrane (Snake sign)
      • Diffusion Weighted (DW) MRI: Differentiates from simple cyst
  • ERCP
    • Purpose: Not for diagnosis but for treatment
    • Uses:
      • Major cystobiliary communication
      • Obstructive jaundice
      • Cholangitis
      • Postoperative bile leak
      • Biliary stricture

Treatment of Hydatid Cyst

  • Surgery
    • Gold Standard: Surgery is the primary treatment
    • Indications:
      • Complicated cysts
      • CE2 and CE3b cysts
      • Superficial cysts prone to spontaneous rupture
    • Contraindications:
      • Diffuse hepatic cysts
      • Dead cysts
      • Inactive cysts
      • CE4 and CE5 cysts
    • Types of Surgery:
      • Conservative Surgery:
        • Deroofing of cyst
        • Injection of protoscolicidal agent
        • Omentoplasty
        • Capitonage
      • Radical Surgery:
        • Cystopericystectomy / Radical Cystectomy
        • Total or Subtotal
        • Liver Resection:
          • Anatomical
          • Non-anatomical
        • Indications:
          • Large multivesicular cysts
          • Peripheral cysts
          • Left lateral segment cysts
          • Pedunculated cysts
          • Extrahepatic abdominal cysts
        • Recurrence Rate: Less but associated with more complications
        • Considerations:No proven superiority of laparoscopic resection over open surgery in terms of recurrence; laparoscopic surgery may carry higher riskMajor liver resection should be avoided if possible
      • Cystobiliary Communication
        • Management:
          • Not an indication for radical surgery
          • Major cystobiliary communication can be managed by closing the communication with PDS or performing ERCP stenting
  • Percutaneous Treatment:
    • Scolicidal Substances:
      • 20% Hypertonic Saline: [WHO recommended]
        • For surgery
        • Contact time: 15 minutes
      • 95% Alcohol:
        • For percutaneous procedures
      • 0.5% Cetrimide
    • PAIR (Percutaneous Aspiration, Injection, and Respiration):
      • Not indicated for complicated or peripheral cysts
      • Destroys germinal layer
    • PEVAC (Percutaneous Evacuation of Cyst Content):
      • Indicated for cysts >6 cm
    • Indications for Percutaneous Treatment:
      • Cyst size < 5-6 cm
      • CE1 and CE3a
      • Absence of cystobiliary communication
    • CONTRAINDICATIONS TO PAIR:
      1. CE 2 (d/t mutiple cysts inside)
      2. CE 3b ,4 ,5
      3. Superficial cysts or exophytic cysts d/t risk of rupture
      4. Biliary fistulae
      5. SIZE IS NOT A C/I.
      6. CE 3a also can be done because there is only one cyst with detached laminated membrane
  • Medical Treatment
    • Albendazole and Mebendazole:
      • Dose: 10-15 mg/kg with fatty meal
      • Mechanism: Inhibits tubulin polymerization and cell division
      • Indications:
        • Cyst < 5 cm
        • CE1 and CE3
      • Praziquantel:
        • Ideal for prophylaxis in preoperative and postoperative settings
        • Administer 1 week before and 2-3 months after surgery
    • Albendazole Therapy:
      • Indications:
        • Small cysts CE1 and CE3a < 5 cm
        • Univesicular, in young patients
      • Parasiticidal Effect: Impairs glucose uptake
      • Monotherapy:
        • Duration: 3-6 months
        • Cure Rate: 80%
      • Contraindications:
        • Risk of rupture
        • Early pregnancy
      • Side Effects:
        • Temporary hair loss (reversible)
        • Leukopenia and bone marrow suppression
      • Post-Surgery:
        • If cyst spillage occurs during surgery: Continue albendazole for 6 months
        • For uncomplicated cases: 4-8 weeks postoperative
      • Dose: 10-15 mg/kg
      • Monthly Treatment Interruption: No longer recommended

Management Indications and Contraindications

Management Indications Contraindications
Surgery Large CE2-CE3b with multiple daughter vesicles, single superficial cysts, complicated cysts General contraindications, uncomplicated CE4 and CE5, very small cysts
PAIR CE1 > 5 cm, CE3a > 5 cm, inoperable patients, refuse surgery, relapse, failure with BMZ Biliary fistulae, CE2, CE3b, CE4, CE5
Medical (BMZ) CE1 < 5 cm, CE3a < 5 cm, inoperable patients, refuse surgery, multiple cysts in >2 organs, peritoneal cysts, recurrence prevention Pregnancy, uncomplicated CE4 and CE5, cysts > 10 cm, cysts at rupture risk, chronic hepatic disease, bone marrow depression

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Echinococcus multilocularis

  • Also Known As: Alveolar hydatid cyst (despite not affecting the lung)
  • Primary Disease Location: Liver only
  • Extrahepatic Disease: Rare
  • Characteristics:
    • Larva has a tendency to metastasize or infiltrate, resembling a tumor
    • Can rupture into the bloodstream
    • PNM Classification:
      • P: Parasitic mass
      • N: Neighboring organs
      • M: Metastasis
  • Definitive Host: Fox
  • Brood Capsule and Protoscolices: Rarely formed
  • Treatment:
    • Surgical Treatment:
      • Formal liver resection (R0 resection)
      • Not Recommended: Deroofing
      • Palliative Surgery: Should be avoided
    • Transplant: Considered in rare cases
    • If Inoperable:
      • BMZ Treatment: Lifelong treatment required
      • Albendazole: Parasitostatic, improves survival

HYDATID CYST MCQ’s

MCQ: Identify the Incorrect Risk Factor for Cystobiliary Communication in Hydatid Cyst

Options:

  • A) Size more than 10 cm
  • B) Increased GGT
  • C) Location near hilum
  • D) Absence of pericyst

Correct Answer: D) Absence of pericyst

Explanation:

  • A) Size more than 10 cm: True—Larger hydatid cysts (>10 cm) are more likely to communicate with the biliary tree due to increased pressure and proximity to bile ducts.
  • B) Increased GGT: True—An elevated Gamma-Glutamyl Transferase (GGT) level may indicate biliary obstruction or communication with a cyst.
  • C) Location near hilum: True—Cysts located near the hilum have a higher risk of biliary communication due to the close proximity to major bile ducts.
  • D) Absence of pericyst: False— While the pericyst aspect is important, the absence of a pericyst is not typically listed as a risk factor for cystobiliary communication.

Risk Factors for Cystobiliary Communication in Hydatid Cysts

Key Risk Factors:

  • Age: Older age increases the likelihood of cystobiliary communication.
  • Jaundice: Presence of jaundice is a significant predictor.
  • Past History of Hydatidosis: Previous hydatid infections may increase the risk.
  • Preoperative GGT Levels: Elevated Gamma-Glutamyl Transferase (GGT) levels are associated with a higher risk of biliary communication.
  • Pericyst Aspect: The condition of the pericyst (the fibrous layer surrounding the cyst) is a key factor.
  • Morphologic Cyst Aspect: Certain morphological characteristics of the cyst increase the risk.
  • Location Near the Hilum: Cysts located near the hilum of the liver are more likely to communicate with the biliary tree.
  • Cyst Diameter:
    • Greater than 10 cm: An independent clinical predictor of intrabiliary rupture.
    • Greater than 75 mm: Likelihood of cystobiliary fistula increases to 79%.

Non-Risk Factor:

  • Absence of Pericyst: While the pericyst aspect is important, the absence of a pericyst is not typically listed as a risk factor for cystobiliary communication.

Conclusion:

The absence of pericyst is not considered a predictive factor for cystobiliary communication, whereas cyst size, location near the hilum, elevated GGT, and certain pericyst aspects are significant predictors.

Case Summary

Patient: 45-year-old female

Presentation: Abdominal pain

Imaging Findings:

  • CT Scan: Cystic space-occupying lesion (SOL) with daughter cysts, measuring 8 x 5 cm.
  • USG: Minimal central intrahepatic biliary radicle dilatation (IHBRD).

Lab Results:

  • Bilirubin: 3.5/2.5 mg/dL (Total/Direct)
  • Alkaline Phosphatase (ALP): 440 U/L
  • AST (Aspartate Aminotransferase): 45 U/L
  • ALT (Alanine Aminotransferase): 55 U/L

Suspicion: Hydatid cyst with potential cystobiliary communication (CBC).

Management Options:

  • A) ERCP before surgery
  • B) MRCP
  • C) Surgery
  • D) ERCP after surgery

Correct Answer: A) ERCP before surgery

Rationale:

  • MRCP (B): Magnetic Resonance Cholangiopancreatography (MRCP) is recommended first to assess for the presence of cystobiliary communication (CBC).
  • ERCP before surgery (A): Performing an ERCP before confirming CBC with MRCP is not recommended. ERCP is reserved for cases where MRCP has confirmed CBC, allowing targeted intervention either before or after surgery.
  • Surgery (C): Surgery may be indicated based on MRCP findings and clinical status, but performing it without prior imaging (MRCP) to assess for CBC is not the best initial step.
  • ERCP after surgery (D): If CBC is confirmed postoperatively or complications arise, ERCP after surgery may be required.

Summary:

  • The correct sequence is to perform MRCP first to confirm CBC. If CBC is confirmed, ERCP should be performed either before or after surgery, depending on the clinical situation. Therefore, ERCP before surgery without confirmation by MRCP is the incorrect option here.

Key Points on Endoscopic Retrograde Cholangiopancreatography (ERCP) in Suspected Cystobiliary Communication

  • Initial Investigation:
    • Minor cystobiliary communications should be investigated using noninvasive methods such as MRCP, ultrasound, and CT.
  • Role of ERCP:
    • ERCP is critical in cases of major rupture into the biliary tree.
    • Allows for diagnosis of major biliary communication.
    • Enables clearance of the common bile duct before surgery or intervention via sphincterotomy.
  • Therapeutic Indications for ERCP:
    • Early Postoperative Events:
      • Persistent biliary fistula. [Random point: high ouput biliary fistula cutoff is >200ml ; ECF cutoff is >500ml]
      • Obstructive jaundice.
    • Late Postoperative Events:
      • Sclerosing cholangitis.
      • Sphincter of Oddi stenosis.
    • In cases of biliary fistula accompanied by biliary strictures, sphincterotomy should be supplemented with biliary stenting.
  • Nasobiliary Drainage:
    • An option in cases of biliary sepsis, especially when bile ducts are filled with hydatid elements.

Summary:

  • ERCP is primarily reserved for cases where major cystobiliary communication or rupture into the biliary tree is suspected, particularly when there is a need to clear the common bile duct before surgery or treat postoperative biliary complications. Minor communications should be evaluated using noninvasive imaging methods such as MRCP before considering ERCP.

Case Summary

Patient: 35-year-old female

Presentation: Abdominal pain and jaundice

Imaging Findings:

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  • CT Scan: Cyst measuring 8 x 5 cm
  • Hydatid Serology: Positive

Management Options:

  • A) Albendazole
  • B) Deroofing
  • C) MRCP
  • D) PAIR (Puncture, Aspiration, Injection, Re-aspiration)

Correct Answer: D) PAIR

Rationale:

  • Albendazole (A): Antiparasitic medication often used preoperatively or in certain cases of hydatid disease to reduce cyst viability.
  • Deroofing (B): A surgical procedure that can be performed to manage hydatid cysts, particularly when there is suspicion of cystobiliary communication (CBC).
  • MRCP (C): Magnetic Resonance Cholangiopancreatography is recommended to assess for cystobiliary communication, which is essential given the patient’s symptoms of jaundice and the location of the cyst.
  • PAIR (D): PAIR is contraindicated in cases of CE2 and CE3b cysts, and also when there is a suspicion of cystobiliary communication, as in this patient with jaundice and a positive hydatid serology. PAIR can lead to spillage and further complications in these scenarios.

Summary:

  • PAIR is not recommended in this case due to the presence of a CE2 hydatid cyst (as suggested by the CT findings) and the potential for cystobiliary communication (CBC). The correct approach involves Albendazole therapy, possible deroofing, and an MRCP to further evaluate the cyst's relationship with the biliary tree.

Case Summary

Patient: 35-year-old female

Presentation: Abdominal pain and jaundice

Imaging Findings:

  • CT Scan: Cyst measuring 8 x 5 cm, suspected hydatid cyst
  • Hydatid Serology: Positive
  • MRCP: Shows cystobiliary communication with the right posterior duct

Lab Results:

  • Bilirubin: 4.5/3.2 mg/dL (Total/Direct)
  • Alkaline Phosphatase (ALP): 440 U/L
  • AST: 85 U/L
  • ALT: 65 U/L

Management Options:

  • A) ERCP and stenting
  • B) Cyst deroofing with closure of communication
  • C) Cystopericystectomy
  • D) Right hepatectomy
  • E) None of the above

Correct Answer: E) None of the above

Rationale:

  • ERCP and stenting (A): Appropriate for managing the cystobiliary communication by decompressing the bile ducts and preventing bile leakage.
  • Cyst deroofing with closure of communication (B): A valid surgical option to treat the hydatid cyst and address the cystobiliary communication directly.
  • Cystopericystectomy (C): Surgical removal of the cyst along with the pericyst is another appropriate option in managing hydatid cysts, especially with complications like cystobiliary communication.
  • Right hepatectomy (D): May be indicated in extensive disease, multiple cysts, or when there is significant damage or involvement of the liver segments, particularly in cases where preserving liver function would be challenging.

Summary:

  • All the listed management options (A, B, C, D) are appropriate based on the patient’s condition and findings. The best approach would depend on the extent of the disease, the patient's overall health, and surgical considerations. Therefore, none of the options should be excluded, making E) None of the above the correct answer.

Case Summary

Patient: 36-year-old male

Presentation: Non-specific symptoms

Imaging Findings:

  • CT Scan: Shows a hydatid cyst that is calcified, consistent with CE4/CE5 stage.

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Hydatid Serology: Positive

Management Options:

  • A) Albendazole
  • B) Observation (Correct Answer)
  • C) Surgery
  • D) PAIR

Correct Answer: B) Observation

Rationale:

  • CE4/CE5 Hydatid Cysts:
    • These stages indicate inactive or calcified cysts, which are typically considered non-viable and have a low risk of complications.
  • Observation (B):
    • The best approach for calcified CE4/CE5 cysts is observation since they are typically non-viable and unlikely to cause complications.
  • Albendazole (A):
    • Antiparasitic treatment is generally not required for calcified cysts, as they are non-viable.
  • Surgery (C):
    • Surgery is reserved for symptomatic or complicated cysts, which is not indicated for calcified, inactive cysts.
  • PAIR (D):
    • PAIR is contraindicated in calcified cysts due to the risk of complications and the non-viability of the cyst.

Summary:

  • Observation is the appropriate management strategy for a calcified hydatid cyst (CE4/CE5), as these cysts are non-viable and unlikely to cause further issues. Therefore, the correct answer is B) Observation.