Bone marrow biopsy instrument

Abstract

A surgical instrument for performing tissue biopsies with a single tissue penetration. The elongated instrument comprises a hollow aspirate needle for aspirating bone marrow fluid, a hollow biopsy needle telescoped within the aspirate needle, and a solid stylet removably telescoped within the biopsy needle, all of which coaxially fit together. The stylet comprises a sharp distal end extending outwardly from the biopsy needle for initially penetrating body tissue and occluding the interior of the biopsy needle. The biopsy needle comprises a distal end normally projecting from the aspirate needle for thereafter penetrating a bone and obtaining a solid bone marrow sample. The bulbous, biopsy needle distal end is sharpened for captivating a specimen. It has a pair of relief slots dividing it into bulbous halves that are compressed together when the needle coaxially moves through the aspirate needle after withdrawal from tissue. In operation, the instrument is first inserted through skin and muscle tissue to the bone surface. The stylet is then withdrawn. As the instrument subsequently penetrates the cortical bone and enters the bone marrow cavity, the biopsy needle fills with a tissue sample. The biopsy sample is captivated by compression of the bulbous portion as that needle segment is removed. Afterwards, the outer, aspirate needle that remains in place in the bone is suctioned by an attachable syringe, and liquid bone marrow from the marrow cavity is aspirated into the syringe.