Effect of needle gauge, level of anticoagulation, and target organ on bleeding associated with aspiration biopsy. Work in progress.

Percutaneous fine-needle aspiration biopsy has gained wide acceptance due to its accuracy, ease of performance, and safety. This study was performed to evaluate the effect of needle size, coagulation impairment, or biopsy of different organs on risk of bleeding during the procedure. Multiple biopsy procedures were performed on the livers and kidneys of anesthetized pigs with 14-22-gauge Chiba-type needles. The procedures were performed under direct vision at laparotomy, and blood loss was measured. While larger needles generally produced more bleeding, the differences were statistically significant only when comparing 14- with 16-gauge needles and 16-gauge needles with the group of 18-, 20-, and 22-gauge needles in the liver. In the kidney, no significant difference was noted between 18-, 20-, and 22-gauge needles. Anticoagulation did not produce significantly greater blood loss but did allow separation of the group of 18- and 20-gauge needles from 22-gauge needles in the kidney. Renal biopsy resulted in greater overall blood loss than did liver biopsy.