Indications for needle aspiration in liver abscess are

Therapeutic needle aspiration of amebic abscesses has been proposed. However, a Cochrane systematic review did not suppo any benefit of therapeutic aspiration in addition to metronidazole treatment over metronidazole treatment alone to hasten clinical or radiologic resolution of amebic liver abscesses.19 In general, aspiration is recommended for diagnostic unceainty, with failure to respond to metronidazole therapy in 3 to 5 days, or in abscesses thought to be at high risk for rupture. Abscesses Larger than 5 cm in diameter and in the left liver are thought to carry a higher risk of rupture, and aspiration should be considered. Ref: Sabiston 20th edition Pgno :1452