Periprostatic Nerve Block During Transperineal Prostate Biopsy Under General Anaesthesia: Protocol for a Multicentre Pilot Randomised Controlled Trial.

Background: Transperineal prostate biopsy (TPPB) has become the preferred diagnostic approach due to superior apical sampling and a lower risk of post-biopsy sepsis, without compromising cancer detection. Although routinely performed under general anaesthesia in Australia, early post-operative pain remains common. Periprostatic nerve block (PPNB) improves tolerability when TPPB is performed under local anaesthesia, but its efficacy as an adjunct under general anaesthesia is unknown. This pilot trial evaluates whether PPNB reduces early post-operative pain and analgesic requirements following TPPB under general anaesthesia. Clinical Trial Design and Timeframe: A multicentre, double-blind, RCT conducted across three tertiary centres in Sydney, Australia. Men undergoing TPPB under general anaesthesia are randomised 1:1 to receive bilateral PPNB with lignocaine or placebo immediately prior to biopsy. Endpoints: The primary endpoint is post-operative pain measured using a 10-point visual analogue scale prior to discharge. Secondary endpoints include post-operative analgesic consumption, complication rates, procedure duration, and number of biopsy cores. Data Sources and Statistical Analysis Plan: Clinical and outcome data are collected prospectively. Between-group comparisons will be performed using independent-samples t-tests or Mann-Whitney U tests, as appropriate. Categorical outcomes will be analysed using χ2 or Fisher's exact tests. Statistical significance is defined as p < 0.05. Strengths and Limitations: This multicentre, double-blind randomised design strengthens internal validity, although the modest sample size and reliance on early patient-reported pain may limit detection of smaller effects and longer-term outcomes.