Bone Marrow Biopsy Needle Design Influences the Bone Content of Recovered Specimens.

Introduction: The integrity and composition of bone marrow core biopsies may be influenced by many parameters including patient age, sex, bone density, operator experience, needle selection and biopsy technique. Biopsy needle design impacts on a needle’s performance and the quality of recovered specimens. We studied the effect of modifying the Snarecoil bone marrow biopsy needle tip on the recovery of trabecular bone in core specimens.

Methods: 7 patients, ages 35–92, M/F = 4/3, (2 leukemias, 1 lymphoma, 1 cytopenia, 1 anemia, 2 other) underwent a bone marrow biopsy using a 8 gauge Snarecoil needle with a new needle tip (TPNSP). The tip has a twin peak point and more distal Snarecoil position. As a control group, 7 patients biopsied with a standard 8 gauge Snarecoil needle (NTP) were retrospectively identified and matched for age and sex and were ages 37–87, M/F = 5/2, (3 cytopenias, 2 leukemias, 1 lymphoma, 1 other). All biopsies were completed using a minimally manipulative technique from the left posterior superior iliac spine with 2% lidocaine. The length of the specimen and attached clot was measured. The specimens were decalcified for 90 minutes and otherwise processed in the standard fashion. The percentage of bone per core biopsy was determined with computer-assisted morphometry using a BioGenex iVision V3.5 system.

Results: The study and control groups were comparable, as the mean age and M/F distribution of the two groups and the mean lengths of the recovered specimens were not statistically significantly different. (TPNSP vs. NTP, 63.8±7.1 vs. 64.7± 6.4 p=0.93, 4/3 vs.5/2 p= 0.57, 2.32± 0.26cm vs. 2.21± 0.26cm p=0.761, respectively).

However, the mean percentage of bone in the specimens recovered by the new TPNSP needle was greater than that recovered with the NTP needle. (16.3±1.5% vs. 6.8±1.4%, p= 0.0008). Grossly, the TPNSP specimens had a more linear edge than those of the NTP specimens. Also, more (5/7) of the NTP specimens had > 0.5 cm of attached clot then did the TPNSP specimens (0/7), p=0.005 suggesting that the twin peak needle produced less tissue hemorrhage.

Conclusions: 1. 8 gauge Snarecoil needles having a sharper tip and more distal Snarecoil recover specimens with as much as 2.5 fold more bone for histopathologic study. 2. The twin peak needle may produce less tissue hemorrhage and disruption.