Prostate biopsy quality and patient experience with the novel Forsvall biopsy needle – a randomized controlled non-inferiority trial

Abstract

Background

Transrectal prostate biopsy (TRbx) carries an increasing risk of infection. The Forsvall Needle Prototype (FNP) is a novel biopsy needle that reduces bacterial load brought across the rectum and may therefore reduce infection risk. The objective of this study was to compare biopsy length, quality and patient experience for the FNP Version 2 (FNP2) versus a standard Tru-Cut needle.

Methods

We conducted a randomized, parallel-group, non-inferiority trial with twenty consecutive patients eligible for TRbx. Participants were randomized to undergo TRbx using either FNP2 or a standard Tru-Cut needle. The primary outcome was difference in mean biopsy lengths measured by the pathologist. FNP2 biopsy lengths ≤1.35 mm of the standard needle length were considered non-inferior. Secondary outcomes were biopsy length in the needle chamber and immediately after removal, biopsy quality, biopsy fragmentation, patient discomfort/pain, and complications (immediate and after 14 and 30 days).

Results

Mean pathologist-measured FNP2 biopsy length was non-inferior compared to the standard Tru-Cut needle (0.02 mm longer, 95%CI–0.73 to 0.76 mm). Biopsy length in the needle chamber and immediately after removal were also non-inferior. Biopsy quality and patient discomfort were not significantly different for the FNP2 and the standard Tru-Cut needle. Biopsy fragmentation was more common in the FNP2 group.

Conclusions

The FNP2 biopsy needle is non-inferior to the Tru-Cut needle in terms of biopsy length and not significantly different in terms of biopsy quality and patient experience. Future studies will evaluate the Forsvall needle design’s effect on post-biopsy infection risk.

Keywords:

• Prostate biopsy
• transrectal prostate biopsy
• biopsy core length
• biopsy quality
• post-biopsy infection

Acknowledgement

The authors thank research nurse Annika Skoog, photographer Charlotte Carlberg-Bärg, and statistician Axel Ström.

Disclosure statement

Andreas Forsvall is listed as an inventor on patents for the new (Forsvall) needle system and is also the founder of Saga Surgical AB, a company owning the patent rights for this needle. Other authors have nothing to disclose.

Data availability statement

The FNP2 system is an investigational device and has to undergo FDA-approval and CE-labelling to be made available.

Additional information

Funding

The study was financed by the Gorthon foundation, the Thelma Zoégas fund, the Ollie and Elof Ericsson fund, LIONs research Fund Scania, Vinnova (Sweden’s innovation agency), MedTech4Health, Västra Götalandsregionen (ALF-medel), and the Swedish Prostate Cancer Federation.