US-Guided percutaneous needle biopsy of the spleen using 18-gauge versus 21-gauge needles

Purpose. To compare the techniques of sonographically (US)-guided percutaneous needle biopsy of the spleen using 18-gauge and 21-gauge needles. Methods. Forty-two patients undergoing 43 spleen biopsy procedures for focal lesions (n = 27 [16 single, 11 multiple]) or diffuse splenomegaly (n = 15) were analyzed. Two groups were divided randomly according to needle type: group 1 comprised 25 patients biopsied with an 18-gauge cutting needle for histologic examination; group 2 comprised 17 patients biopsied with a 21-gauge needle for histologic and cytologic examinations. Diagnostic accuracy, complication rate, and number of needle passes were compared between the 2 groups. Results. Correct histopathologic diagnosis was obtained in 36 cases, whereas incorrect diagnosis occurred in 6 cases. The accuracy of US-guided spleen biopsy in this series was 85.7%, with 1 patient (2.4%) having postprocedural hemorrhage. Compared with the 21-gauge needle, the 18-gauge needle had higher diagnostic accuracy (P < 0.05), required fewer needle passes (P < 0.05), and there was no significant difference in overall complication rate. Conclusion. Because biopsy with an 18-gauge needle yields larger and unfragmented samples with higher diagnostic rate compared with a 21-gauge needle, and no increased rate of major complication requiring surgical intervention, it may be advantageous to use an 18-gauge cutting needle in the US-guided needle biopsy of splenic lesions.