Biliary disease accounts for 21-30%, with extrahepatic obstruction leading to ascending cholangitis and abscess. Also CBD stones, benign and malignant tumors, biliary enteric anastamoses.
Infection via portal system Infectious process originates in abdomen, reaches liver by embolization of portal system. Appendicitis, diverticulitis, IBD, proctitis
Hematogenous. Via hepatic artery. From systemic septicemia. No cause in 50% of cases, but increased in diabetics and metastatic cancer.
Access to liver by direct extension from nearby organs. Through portal vein and hepatic artery. Hepatic clearance of bacteria via portal system is a normal phenomena, but organism proliferation, tissue invasion and abscess can occur with biliary obstruction, poor perfusion, microembolization.
Most contain more than one organism, with source biliary or enteric. Blood cultures positive in 33-65%. E.Coli 33%. Klebsiella 18%. Bacteroides 24%. Streptococcal 37%.
Fever, right upper quadrant pain (80%). Right shoulder pain, pleuritic chest pain. Fever 87-100%. Anorexia, weight loss, mental confusion. Physical exam shows RUQ tenderness, hepatomegaly, liver mass, jaundice.
Indications For Open Drainage:
Abscess not amenable to percutaneous drainage Co-existing intra-abdominal disease that requires operative management. Failure of antibiotic therapy. Failure of percutaneous aspiration or drainage.
Age older than 70. Multiple abscesses. Polymicrobial infection. Presence of associated malignancy or immunosupressive disease. Multiple medical problems
Percutaneous Drainage CT or US guided placement of a catheter. Drain is removed once abscess cavity collapses. Success 80-87%. Consider open drainage if fails, or patient worsens over 72 hrs.
Complications of Percutaneous Drainage Perforation of a viscous. Pneumothorax. Bleeding. Leakage of pus into the abdomen. Immunocompromised patients with multiple abscesses are best treated with high dose antibiotics rather than open or percutaneous drainage.
Surgical Therapy Five indications as previously discussed. Presence of peritoneal signs mandates emergent exploration. Transthoracic, extraperitoneal, transperitoneal. Transperitoneal is preferred as intra-abdominal pathology can be dealt with.
Complications Result from rupture of abscess into adjacent organs or cavities. These include both pleuropulmonary and intrabdominal types. Pleuropulmonary are themost common 15-20%, include effusions, empyema, bronch-hepatic fistula. Intraabdominal include subphrenic abscess, rupture into peritoneal cavity, stomach, colon, vena cava, or kidney.