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Surgical Liver diseases - Coggle Diagram

- - - - Entamoeba histolytica. 3rd leading cause of parasite deaths.
        -Tropical/subtropical climates
        -Overcrowding + poor sanitation = predisposing factors
        -Mostly in lower socio-economic backgrounds
    - - Faecal-oral:
        -Ingestion of viable cysts
        -Cyst wall disintegrates in small intestine and motile throphozoites are released
        -Trophozoites migrate to large bowel where pathogenic strains cause invasive disease.
        -Mucosal invasion = flask-shaped ulcers where amoeba gain access to portal system.
        -Liver amoebic abscesses usually solitary and involves right lobe in 80% cases.
        -Abscess contains sterile pus and reddish-brown liquefied necrotic liver tissue=anchovy paste appearance. Viable amoebae may be at periphery of abscess.
    - - Pain, patient appears toxic, febrile and chronically ill, intermittent fever, night sweats, weight loss, nausea, vomiting, cough, dyspnoea. Hepatomegaly most tender over abscess.
        Complications= secondary infection, rupture into adjacent structures like pleural, pericardial or peritoneal spaces. 2/3 ruptures= intraperitoneal 1/3= intrathoracically.
    - - History + serological tests: Resident in/visited endemic area. Hx of predenign diarrhoea sometimes.
        -Leucocytosis 70-80% polymorphs
        -Elevated ESR/CRP
        -Moderate anaemia
        -ALP + bilirubin elevated = severe disease with multiple abscesses
        -Stool exam=cysts or haematophagous trophozoites (in dysentery)
        -Indirect haemagglutination titires for Entamoeba elevated in 90%.
      - Imaging: cxr: Raised right diaphragm with atelectasis/pleural effusion.
        -US: shows size of abscess. guides aspiratipn, assess response to therapy
        -Cross sectional imaging (CE-CT/MRI): better assess anatomic location and proximity to structures.
    - - US guided aspiration = if serology is negative; abscess is >10cm, not a satisfying response to treatment or with impending peritoneal, pleural or pericardial rupture (seen more in left liver).
      - Surgical drainage=if abscess has ruptured with amoebic peritonitis or no response to medical treatment in spite of needle aspiration or catheter drainage.
      - Supportive measures: fluid resus, pain relief. -Metronidazole 800mg 3 times a day for 5 days. (symptoms imporve within 24 hours). + Luminal amoebicidal agent (diloxanide furoata, iodoquinol, paromomycin) to eradicate eventual intesinal parasites.
  - - - Most commonly caused by:
        
        Echinococcus granulosis: worlwide, endemic in sheep farming countries including SA.
        
        E. multilocularis: causes alveloar echinococcosis= in Northern hemisphere.
        3.+4. E. vogeli and E. oligarthrus: in central/South America.
    - - Whether becomes symptomatic depends on location, size and parasite load. -RUQ discomfort/pain (pressure), hepatomegaly. Complications: cyst rupture into abdominal/peritoneal cavity (=anaphylactic reaction with urticaria + shock; not treated=peritonealhydatosis with implantation of daughter cysts onto omentum and other viscera)), pleural cavity and lungs (perfpration thrpugh diaphragm and communication with lung and bronchus=couhging up grape skins=uncommon), compression of (=jaundice) or erosion (=cholangitis with secondary infection of cysts) into biliary system and secondary infection.
    - - E. granulosis: definitive host: dogs; intermediate sheep
        E. multilocularis: def: foxes; intermediate: rodents. Humans are accidental intermediate hosts.
        
        Adult worms live in small bowel of dogs where they attach to mucosa and shed eggs in gut.
        
        ova are resistant to drying and remain viable for several weeks after being passed.
        
        The sheep ingests ova while grazing. Ova hatch in bowel, enter portal circulation ad develop in liver.
        
        Lifecycle completed when dog eats contaminated raw offal.
        
        Man is accidental intermediate and contracts disease when ingesting ova in faeces passed by infected dogs.
        
        Ova penetrate intestinal wall and pass through portal vein with cysts occurring in liver (63%), lung (25%), muscles (5%), bones (3%), kidneys, brain and spleen.
        
        Mature cyst has 3 layers: inner germinal layer, middle acellular laminated layer and outer fibrous host peri cyst layer. laminated and per cyst layers becomes calcified in older cysts. germinal layer produces daughter cysts and brood capsules containing scolices which, if ingested by dogs, spread the disease.
    - - -US: diagnosis can be made -CE-CT: superior in determining size, position and extent if disease. -MRI: shows septations better.
        -Eosinophilia in 40%, more when ruptured. diagnoiss uspported by serological haemagglutination and complement fixation tests.
        -With biliary infiltration/cholangitis: ERCP and biliary drainage
    - - Surgical:Open surgery through laparotomy= gold STD. 1. mechanical removal of cyst contents, inlcuding daughter cysts. 2. Sterilization of cyst cavity by injection of scolicidal agent. a. Isolation of operative field by abdominal swabs soaked in scolicidal agent (Eusol, 15-20% hypertonic saline, formalin, hydrogen peroxide, chlorhexidine, absolute alcohol, cetrimide) to prevent implantation. b. Cyst fluid aspirated and replaced by scolicidal agent. agent not injected if bile leak (chemical injury =sclerosing cholangitis). Repeated until clear. c. Once cyst decompressed = cyst and contents shelled out by peeling the lmainated membrane off peri cyst layer along its cleavage plane. Fibrous host wall of residual cavity is carefully exmained for bile leak and leaks sutured closed. Cavity drinaed with closed drainage system. Procedure can be laparoscopically/percutaneous aspiration, inject and re-aspiration (PAIR) followed by cather drainage. Liver resection seldom necessary.
      - Preventative measures: deworming dogs, imporving slaughterhouse hygiene and public education
      - Medical treatment: Benzimidazole (albendazole 10-15 mg/kg/d or medendazole 40-50mg/kg/d). Only given alone when surgery contraindicated/disseminated inoperable disease. Albendazole one month before op and 2 months post op= decreased recurrence rates. Side effects=bone marrow depression, liver and renal toxicity (monitor FBC+LFTs every second week)
  - - - Trauma: penetrating vs blunt
      - Via the hepatic artery: dental infection, bacterial endocarditis, IV drug abuse
      - Iatrogenic: liver biopsy, percutaneous biliary drainage
      - Cryptogenic: unknown cause
      - Via the portal vein: Appendicitis, diverticulitis, IBD, pelvic sepsis
      - Direct extension: Gall bladder empyema, perforated peptic ulcer
      - Via the biliary duct: biliary stones, benign or malignant bile duct strictures, sclerosing cholangitis
    - - -Polmicrobial:mostly gram negative aerobic/anaerobic:
        Most part of colonic microbiome: (Escherichia coli, Klebsiella pneumoniae, Bacteroides
        species, Enterococci)
        Staph/Strep= found with arterial spread
        immunosuppression (HIV, oncological therapy + transplantation) =fungal/opportunistic organisms = abscesses.
    - - Abdominal pain, swinging pyrexia, (night) sweating, vomiting, anorexia, malaise, weightloss, tender hepatomegaly (esp on percussion of lower ribs.) Palpbale spleen in chronic cases, clinical jaundice=suppurative cholangitis, can be fever of unknown orgin. ascites is uncommon
        -Insidious/occult in elderly
        -single abscess=gradual onset; cryptogenic
        -Multiple=acute systemic features; established cause
    - - Imaging:
        -US preferred first line (single abscess=US guided aspiration and drainage)
        -On film: air fluid level in abscess cavity. Right diaphragm elevated with sympathetic effusion/pneumonic consolidation
        -CT scan: depicts extent and location of abscesses accurately and can identify intra-abdominal source of infection.
      - Bloods: -Leucocytosis (WCC normal in seriously ill)
        -ESR + CRP elevated
        -Anaemia in chronic infection
        -ALP raised with hypoalbuminaemia
        -AST+ALT marginally elevated
    - - -Antibiotics: choices depend on most common organisms at facility. Here= ceftriaxone + ampicillin/clindamycin (in peniciilin allergy). AMoebic abscess=metronidazole . Antibiotics chnaged once cultures confirmed. Prolonged course=oral agents afetr 2 weeks.
        Duration depends on clinical pcture, radiographic characetristics and patient progress.
        4-6 weeks therapy; multiple abscesses where ddrainage of all collections not achiebeable=12 weeks therapy.
        
        Drainage of abscess by percutaemeous aspiration or catheter placement for contiinued drainage and flushing or drainage at laparoscopy or laparotomy.
        
        -Underlying causes should be managed e.g. biliary obstruction with cholangitis= ERCP stent/PTC with drainage.