EXPERIMENTAL QUALITY-CONTROL OF BIOPSY NEEDLES

To examine the quality and comparability of biopsy needles. 310 biopsy needles of 40 types were examined microscopically and their suitability for penetrating tissues were studied. For this purpose the pressure required to penetrate a phantom was evaluated. The results were correlated with the diameter, design and construction. 50 of the 310 needles (16%) showed faults on microscopic examination. Measurements of identical needle types within a single production run showed variations in penetration pressures up to 330 % (measured as force required for penetration), the average variation was 88%. The results show that the quality of biopsy needles is not constant and leaves something to be desired. To what extent variations in quality affect the biopsy material cannot be estimated. Nevertheless, the present results indicate that stricter quality control of biopsy needles is desirable.