What is the recommended technique for performing a periprostatic nerve block?

Periprostatic Nerve Block Technique

Periprostatic nerve block using bilateral injection of 5-10 mL of 1% lidocaine into the apex of the prostate at the neurovascular bundle is the gold standard technique for pain control during transrectal ultrasound-guided prostate biopsy. 1

Patient Preparation and Equipment

• Position the patient in the lateral decubitus or lithotomy position with appropriate exposure for transrectal ultrasound probe insertion 1
• Use standard aseptic technique similar to neuraxial procedures for equipment preparation 2
• Calculate safe lidocaine dosing: maximum 4.5 mg/kg without epinephrine or 7 mg/kg with epinephrine 1, 3
• Have resuscitation equipment immediately available and monitor vital signs, particularly in patients with cardiovascular risk 4

Ultrasound-Guided Injection Technique

• Insert the transrectal ultrasound probe and identify the prostate apex and lateral borders where the neurovascular bundles course 5
• Inject 5 mL of 1% lidocaine bilaterally at the apex of the prostate at the junction between the prostate and seminal vesicles, targeting the periprostatic nerve plexus 5, 6
• Use ultrasound guidance to visualize needle placement and ensure proper distribution of local anesthetic 1
• Wait 5-10 minutes after injection before proceeding with biopsy to allow adequate anesthetic effect 5

Enhanced Pain Control Strategies

• For patients requiring additional analgesia, consider combining periprostatic block with intraprostatic injection of 5 mL of 2% lidocaine, which provides superior pain control especially in younger patients (≤66 years) or those with smaller prostates (≤48 mL) 7
• Adding tramadol 25 mg to the lidocaine solution (5 mL of 2% lidocaine + 25 mg tramadol) significantly reduces pain scores compared to lidocaine alone 8
• Apply 10 mL of 5% lidocaine cream perianally 10 minutes before probe insertion to reduce pain during early procedural stages, though this only addresses probe insertion pain and not biopsy pain 9, 1

Critical Pitfalls to Avoid

• Do not rely solely on intrarectal lidocaine gel, as it only addresses probe insertion discomfort and provides no pain control during the actual biopsy sampling 1, 6
• Avoid inadequate waiting time after injection—the full anesthetic effect requires 5-10 minutes 5
• Do not proceed with extended biopsy templates (>12 cores) without adequate anesthesia, as these require more robust pain control 1

Special Circumstances

• For patients with anal strictures, inadequate response to periprostatic block, or saturation biopsies (>20 cores), consider intravenous sedation or general anesthesia 1
• Periprostatic nerve block is safe and does not increase complication rates compared to no anesthesia 5, 6
• The technique is simple, cost-effective, and does not require additional procedural time 5

Expected Outcomes

• Periprostatic nerve block reduces mean pain scores from 4.5-5.4 (without block) to 1.5-3.6 (with block) on a 10-point visual analog scale 5, 8, 6
• The technique is effective regardless of patient age, prostate volume, or number of biopsy cores when used as the baseline approach 5
• Minor transient complications may occur but are equivalent to rates without anesthesia 5