The long core needle with an end-cut technique for prostate biopsy: does it really have advantages when compared with standard needles?

Abstract

To evaluate the failure rate, core length and fragmentation rate for each different stroke length of the end-cut (BioPince) needle in order to show the performance of the needle for different stroke lengths and compare these with the standard side-notch needle. TRUS guided biopsy of the prostate was performed on 86 consecutive men between June 2002 and May 2003. The patients were randomized into two groups with 43 men in each group. Patients in group A underwent 8 core biopsy with the end-cut needle in different stroke lengths; 13, 23 and 33mm respectively. Patients in group B underwent 8 core biopsy with the side-notch needle. The cores have been evaluated and compared for failure rates, core lengths, number of core lengths under 5mm and fragmentation rates. When the end-cut needle was used, a significant number of failure rates was noted; with an overall failure rate of 16%. The failure rates were 26% for 13mm stroke length, 18% for 23mm stroke length and 10% for 33mm stroke length respectively. These failure rates showed statistically significant difference from standard needle for overall and for every separate stroke length ( p<0.001 for all). Standard needle and the cores taken with 33mm stroke length of the end-cut needle had similar low fragmentation rates while 13 and 23mm stroke lengths had higher rates. Of the overall cores taken by BioPince needle, 46/344 (13%) of the cores were shorter than 5mm and this was significantly higher than the standard needle with 3/344 cores less than 5mm ( p<0.001). The end-cut needle when used with the 33mm stroke length has improved the core length by 68% according to the standard side-notch needle. Our results showed that the performance of the end-cut needle worsens with decreased stroke lengths. The end-cut needle showed high failure rates which necessitates new punctures for taking a core. Additionally, the fragmentation rates are not lower than the standard needle and it has higher rates of taking small core samples. The only significant advantage of this needle over the standard needle is taking longer cores when it has been used at 33mm stroke lengths.