In pyogenic liver abscess commonest route of spread is:

Ans is 'b' ie Ascending infection through biliary tract "Along with cryptogenic infections, infections from the biliary tree are presently the most common identifiable cause of hepatic abscess. Biliary obstruction results in bile stasis, with the potential for subsequent bacterial colonization, infection and ascension into the liver. This process is k/a ascending suppurative cholangitis. The nature of biliary obstruction is mostly related to stone disease or malignancy. In Asia, intrahepatic stones and cholangitis (recurrent pyogenic cholangitis) are a common cause, whereas in the Western world, malignant obstruction is becoming a more predominant factor" - SabistonRoutes of infection to liver:along the bile ducts (MC)* stone impacted in CBDstricture of CBD - benign, malignantCryptogenicvia the portal veinvia the hepatic arteryby direct extension from a subdiaphragmatic abscess from an empyema in chest from suppurative cholecystitis from perinephric abscessPenetrating or blunt traumaAlso know:MC organisms (Ref. Sabiston, Schwartz)Escherichia coli Klebsiella pneumonia