Liver biopsy is a common diagnostic procedure performed in cases of suspected liver disease to establish a definitive diagnosis. There are various ways of obtaining hepatic tissue including:
•Blind percutaneous needle biopsy
•Transjugular biopsy
•Image guided [ultrasound or CT] percutaneous needle biopsy and
•Laparoscopic vision-guided needle biopsy.
Contraindications-
•Impaired coagulation
•Significant ascites
•Echinococcal [hydatid] disease
•High grade extrahepatic biliary obstruction.
Complications following liver biopsy-
•Pain [most common] - is usually confined to right shoulder due to diaphragmatic irritation.
•Hemorrhage – post biopsy bleed can be intrahepatic, in the vicinity of the liver capsule [capsular/ subcapsular], into the biliary tree [hemobilia] or into the abdomen [hemoperitoneum].
•Bile leakage and peritonitis
•Laceration or perforation of adjacent organs
•Pneumothorax
•AV fistula.
Ultrasound guided liver biopsy is a relatively safe diagnostic procedure; ultrasound guidance increases the diagnostic yield of the biopsy and reduces complication rates. Significant hemorrhage is rare, but is the most common cause of mortality. Bleeding usually occurs due to tear of a distended portal or hepatic vein. Asymptomatic intrahepatic hematomas may occur following a liver biopsy and hence ultrasonic surveillance in high risk patients is advocated. According to a study by Gonciarz, et al if clinically relevant intrahepatic hematomas were not detected 4 hours post biopsy, then no further follow up was needed. Most researchers advocate a 24 hour follow up. However, delayed hemorrhage from the biopsy site may go unsuspected. This is a seldom appreciated fact and must be remembered.
The intrahepatic hematoma in the acute stage is seen as a well-defined, hypoechoic mass with low level echoes in the area of the puncture site. The mass shows good sound transmission. Later as the hematoma ages it becomes more heterogeneous and hyperechoic.
Most of the intrahepatic hematomas resolve spontaneously without the need for any intervention. However, periodic ultrasonic monitoring is recommended.