Roberts, Catherine C.

Background: Needle biopsy has proven to be a potentially adequate method for initial biopsy of many soft-tissue and bone lesions. To help optimize this procedure, this study sought to test the characteristics of several needles, including a steerable needle. Materials and Methods: Five needle types were tested, including a steerable needle. Animal muscle tissue was used for all testing. The following experiments were performed: (1) sample collection with different needle types, (2) histological analysis of needle track, (3) observation of steerable needle characteristics using CT-guidance. Results: Sample collection: The Menghini 21 g and Chiba 22 g needles were graded as excellent for ease of use and integrity of sample. Histologic evaluation showed good specimen preservation with all needle types. Histological analysis of needle track: tracks created by the Menghini 21 g and Spinal 20 g needles both showed no histologically detectable damage to surrounding tissue. Observation of steerable Menghini needle under CT-guidance: needle advanced easily through tissue, even when maximally curved. Small, large, and double curves were feasible to avoid obstacles and reach targets. There was no deflection or change in position of the needle tip when the stylet was removed. Needle withdrawal did not damage surrounding tissue. Conclusions: Compared to the other needles, the steerable needle was found to be durable and easy to use, allowing for precise navigation around vital structures yielding superior integrity of sample tissue.