Factors influencing urinary retention after transperineal template biopsy of the prostate: outcomes from a regional cancer centre

Introduction Multi-parametric MRI (MP-MRI) prior to prostate biopsy is the investigation of choice for an elevated age-related PSA and abnormal digital rectal examination. MP-MRI in combination with transperineal template mapping biopsy has facilitated the development of the concept of targeted biopsies, either cognitively or with software fusion. Urinary retention is a recognised complication of transperineal prostate biopsy, with reported incidence being 1.6-11.4%. We present patient and procedure-related factors, which influence occurrence of urinary retention after transperineal template biopsy. Patients and methods Retrospective data collection of 243 consecutive cases of transperineal template biopsies performed at a single institution were recorded and analysed. Biopsies were taken using a standard 5-mm template in 4-6 sectors, depending on the prostate volume. Results 31/243 (12.8%) patients developed urinary retention, defined as patient discomfort and inability to micturate and bladder scan of 600ml. Patients in the retention group were significantly older (mean 68.7 vs. 65.8years, P=0.034). Prostate volume was significantly greater in comparison with the non-retention group (mean 75.4 vs. 57.2cc, P=0.0016). The number of biopsies taken was positively correlated with urinary retention (median 35 vs. 32 biopsies, P=0.045), and this was independent of prostate size (R-2=0.2). Presenting PSA, pre-operative flow and histopathological outcome were independent of urinary retention. Conclusions Factors resulting in an increased risk of urinary retention are advancing age (>68.7years); a larger prostate volume (>75cc); greater number of biopsies (>35); greater severity of lower urinary tract symptoms prior to biopsy and diabetes. Targeted biopsies alone, instead of a full template, may avoid urinary retention in the high-risk groups identified.