Abstract: Objective To investigate the influencing factors of tissue length in ultrasound-guided percutaneous transhepatic biopsy. Methods 625 patients underwent ultrasound guided percutaneous by liver biopsy in Nanfang hospital zengcheng Branch between January 2019 and March 2024 were analyzed retrospectively. Patients′ demographic, biochemical indexes, the types of needle, indicators such as complications after paracentesis were collected. The differences of the above indexes between the two groups of single tissue length < 15 mm or ≥15 mm, and the three groups of single tissue length < 15 mm, 15-19 mm and ≥20 mm were compared. Logistic multivariate regression analysis was used to analyze the risk factors of the length of single puncture tissue. The differences of abdominal pain and minor bleeding between the two groups were evaluated. Results The mean specimen length was 11.4 mm in the <15 mm group and 17.8 mm in the ≥15 mm group. The ≥15 mm group had a significantly higher proportion of procedures performed with a full-core needle (45.8%) and by operators with more than one year of experience (65.3%), but a lower incidence of abdominal pain (4.5%). Among the three subgroups (<15 mm, 15~19 mm, ≥20 mm), the use of full-core needles and operators with ≥1 year of experience significantly increased with greater specimen length (P<0.05 for trend). Length of a single tissue < 15 mm and 15-19 mm group, the higher length group accounted for less proportion of abdominal pain (3.6%, P=0.005). Length of a single tissue < 15 mm group and ≥20 mm group, shorter length of group in spleen hardness is higher. The full-core needle is an independent protective factor for the length of single tissue in ultrasound-guided percutaneous transhepatic biopsy. Compared two groups of abdominal pain, female, younger, length is shorter, lower preoperative and postoperative Hb statistic in patients were account for more painful. Conclusion The full-core needle is an independent protective factor for the length of single tissue in ultrasound-guided percutaneous transhepatic biopsy.

Key words: Tissue length, Liver biopsy needle, Ultrasound-guided liver biopsy, Percutaneous by liver biopsy