Canadian Urological Association Journal, cilt.20, sa.7, 2026 (SCI-Expanded, Scopus)
Introduction: Transrectal ultrasound (TRUS)-guided prostate biopsy is often associated with significant discomfort, particularly in patients with underlying anorectal conditions. Conventional local anesthesia techniques, including periprostatic nerve block — widely regarded as the gold standard — may be insufficient for adequate pain control in this patient population, thereby limiting the feasibility and tolerability of the procedure. This study aimed to assess the efficacy of pudendal nerve block (PuNB) and caudal nerve block (CaNB) in improving analgesia for patients with anorectal disease undergoing TRUS-guided prostate biopsy. Methods: This prospective, randomized controlled study included 91 patients presenting with elevated prostate-specific antigen (PSA) levels (≥4 ng/mL) and/or abnormal findings on digital rectal examination, along with coexisting anorectal pathology. Participants were randomly assigned to receive either a PuNB (n=46) or a CaNB (n=45) prior to undergoing TRUS-guided prostate biopsy. Pain intensity was evaluated using the visual analog scale (VAS) at three distinct time points: during local anesthetic administration (VAS-1), transrectal probe insertion and manipulation (VAS-2), and tissue sampling (VAS-3). Results: There were no significant differences between the groups in terms of VAS-1 and VAS-2 scores; however, the CaNB group demonstrated significantly lower VAS-3 scores compared to the PuNB group (1.80±0.89 vs. 2.17±0.70, p=0.048). No major complications were observed in either group throughout the study period. Conclusions: Both PuNB and CaNB techniques provided effective analgesia during TRUS-guided prostate biopsy in patients with anorectal disease; however, the caudal nerve block was associated with significantly lower pain scores during the tissue sampling phase, suggesting it may offer superior pain control in this specific patient population. These findings support the consideration of CaNB as a preferable anesthetic approach in cases where conventional methods are insufficient due to anorectal comorbidities.