**2. Material and methods**

Seventy five cases of percutaneous liver biopsies carried between 2005-2012 were analyzed. The biopsies were performed in children aged 4-17 years (mean 15.30±2.35 years). Study group included 26 girls, 49 boys. Procedures were done due to chronic hepatitis C (CHC) – 44 cases, chronic hepatitis B (CHB) – 16 cases, autoimmune hepatitis (AIH) – 3 cases, hepati‐ tis/hepatomegaly of unknown origin (HUO)– 12 cases, non-alcoholic fatty liver disease (NAFLD) – 2 cases. Number of the procedures performed in the following years has been presented in Figure 1.

Written informed consent was obtained from the parents and patients aged 16 years and over according to Polish law regulations. Before the procedure children were clinically eval‐ uated and blood samples were taken for standard hematological and clinical chemistry anal‐ ysis. Children with coagulopathies and thrombocytopenia below 80,000/mm3 were excluded from the procedure. All children underwent abdominal ultrasound performed the day be‐ fore the procedure to exclude potential hemangiomas and malposition of the organs. All children were managed by Menghini procedure in sedation. Children aged less than 5 years received general anesthesia. 36 biopsies were ultrasound guided directly prior to the proce‐ dure (performed by the operator), 39 biopsies were blind. The ultrasound prior to the biopsy was performed to identify the intercostal space and to avoid accidental puncture of the gall bladder, the lung, right kidney and large vessels. Immediately after the procedure ultra‐ sound examination was performed searching for potential complications such as accidental puncture or bleeding. In the case of blind biopsied ultrasound examination was performed by radiologists in situations where complications were suspected basing on clinical symp‐ toms. All patients were monitored 24 hours after the procedure in the department for vital signs, pain and other consequences.

Histological evaluation was performed using Ishak scoring system for grading and staging.

Categorical variables were compared using Fisher's exact test or chi-square test were appro‐ priate. Result with p value <0.05 were considered statistically significant.

**Figure 1.** Number of liver biopsy performed in the Department of Infectious Diseases and Child Neurology due to vari‐ ous reasons in years 2005-2012 (until July) CHC- chronic hepatitis C, CHB – chronic hepatitis B, NAFLD – non-alcoholic fatty liver disease, HUO – hepatitis/hepatomegaly of unknown origin, AIH – autoimmune hepatitis
