A 39-year-old female one week after laparoscopic cholecystectomy presented to ER … jaundice and RUQ discomfort. Her vital signs are within normal limits but there is … investigations showed WBC count is 12,000/ml, serum T.bilirubin level is 4 mg/dL (0.5-1…) … abdomen reveals a 10 x 10 cm sub-hepatic fluid collection with normal CBD and intrahepatic … The next most appropriate step in management is: