TENS as an Adjunct to Local Anaesthesia During Transperineal Prostate Biopsy: A Randomized Sham-Controlled Trial

N/ANot Yet RecruitingNCT07578324

Medical University of Gdansk140 enrolled

Overview

Transperineal prostate biopsy is a safe and effective method of diagnosing prostate cancer. When performed under local anaesthesia in an outpatient setting, it can cause significant pain, particularly during the periprostatic nerve block - the injection of local anaesthetic around the prostate. Better pain management during this procedure may improve patient comfort and encourage wider use of the transperineal approach. Transcutaneous electrical nerve stimulation (TENS) is a non-invasive, low-cost method of pain relief that works by delivering mild electrical impulses through the skin. A preceding pilot study at our centre (n=84) found that TENS used alongside local anaesthesia was associated with significantly lower pain scores during periprostatic nerve block and biopsy sampling, with no device-related complications. This study aims to confirm these findings in a larger, formally powered, triple-blind, randomized controlled trial. Participants will be randomly assigned to receive either active TENS or sham TENS (electrodes applied but no electrical current delivered) in addition to standard local anaesthesia. Neither the participant, the operating urologist, nor the nurse recording pain scores will know which group the participant is in. Pain intensity will be assessed at four stages of the procedure using a 0-10 numeric rating scale. Participants will be followed up at 30 days after the biopsy.

This is a single-centre, prospective, randomized, triple-blind, sham-controlled, two-parallel-group superiority trial. The study builds on a preceding pilot study (TENS 1, n=84) which demonstrated large effect sizes for TENS-associated pain reduction during transperineal prostate biopsy under local anaesthesia. Triple-blinding is achieved through a three-component procedure: amplitude titration is completed before the operating urologist enters the procedure room; a physical opaque screen is placed between the TENS device and the operative field; and participants are instructed not to verbalise device-related sensations during the procedure. The primary outcome is NRS pain score during periprostatic nerve block, assessed within 30 seconds of completion of bilateral periprostatic infiltration by an independent outcome assessor blinded to allocation. Exploratory outcomes include preoperative pain catastrophizing, preoperative anxiety (STAI-S), and the effect of prior biopsy experience on procedural pain.

Study Type

INTERVENTIONAL

Allocation

Interventions

Transcutaneous Electrical Nerve Stimulation (TENS)DEVICE

Cefar Rehab X2 device (Class II, Type BF). Symmetrical biphasic compensated pulse; 80 Hz; 180 µs pulse duration; amplitude individually titrated. Two pairs of 5x5 cm electrodes in perineal region. Initiated 3-5 minutes before local anaesthesia, continued throughout procedure.

Sham Transcutaneous Electrical Nerve StimulationDEVICE

Identical electrode placement to active group. Device activated without delivering electrical current. Indistinguishable from active TENS by participant, operator, and outcome assessor.

Eligibility

Sex: MALEMin age: 40 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Male patients aged 40 years or older * Indication for prostate biopsy: elevated serum PSA (as per institutional protocol and EAU guidelines) or abnormal digital rectal examination (DRE) * Suspicious lesion on multiparametric MRI classified as PI-RADS score 3 or higher (version 2.1) * Scheduled for transperineal MRI-ultrasound fusion-guided prostate biopsy under local anaesthesia * Ability to provide written informed consent Exclusion Criteria: * Prior treatment for prostate cancer (surgical, radiotherapy, hormonal or focal therapy) * Contraindications to TENS: cutaneous damage or dermatologic conditions at electrode application sites; cardiac pacemaker or implantable cardioverter-defibrillator (ICD); uncontrolled cardiac arrhythmia or congestive heart failure; history of epilepsy or seizure disorder; metallic implants near the stimulation site; malignancy at or near the stimulation site * Contraindications to transperineal biopsy: active urinary tract infection; bleeding disorder or ongoing anticoagulation not amendable to bridging; anatomical abnormalities preventing safe prostatic access * Known allergy or intolerance to local anaesthetic agents or biopsy-related materials * Severe comorbidities or unstable medical condition compromising procedural safety * Inability to complete questionnaires * Participation in another interventional clinical trial within 30 days prior to enrolment

Outcomes

Primary Outcomes

NRS Pain Score During Periprostatic Nerve Block

Patient-reported pain intensity during periprostatic nerve block (PNB), assessed using a Numeric Rating Scale (NRS, 0-10, where 0 = no pain and 10 = worst imaginable pain). PNB consists of periprostatic infiltration ( 10 mL 1% lignocaine under real-time ultrasound guidance). NRS assessed verbally by an independent outcome assessor (Nurse B) within 30 seconds of completion of the PNB injection, before the next procedural stage begins. Standardised verbal NRS explanation provided to all participants before the procedure.

Time frame: Immediately after completion of periprostatic nerve block (intraoperative)

Secondary Outcomes

NRS Pain Score During Ultrasound Probe Insertion

NRS (0-10) assessed within 30 seconds of probe placement, before local anaesthesia administration begins.

Time frame: Immediately after ultrasound probe insertion (intraoperative)

NRS Pain Score During Perineal Infiltration

NRS (0-10) assessed within 30 seconds of completion of perineal skin and subcutaneous tissue local anaesthetic infiltration.

Time frame: Immediately after perineal infiltration (intraoperative)

NRS Pain Score During Biopsy Sampling

NRS (0-10) assessed within 30 seconds of the last biopsy core being obtained.

Time frame: Immediately after fusion-targeted biopsy sampling (intraoperative)

Procedural Safety and Tolerability

Incidence and severity of adverse events classified per Clavien-Dindo grading system.

Time frame: Through 30-day follow-up

Willingness to Repeat the Procedure

Single question (yes/no/unsure) assessing patient willingness to undergo the same procedure in the future.

Time frame: 30-day follow-up visit

Blinding Integrity - James Blinding Index

Participant blinding assessed by single question posed by independent outcome assessor immediately after biopsy sampling: which group the participant believes they were assigned to (active/sham/no opinion), plus certainty rating (1-5).

Time frame: Immediately after biopsy sampling, before unblinding

Operator Satisfaction

Single-item Likert scale (1-5, where 1 = very dissatisfied and 5 = very satisfied with procedural conditions), recorded by the operating urologist immediately after the procedure, assessing overall satisfaction with procedural conditions during the biopsy.

Time frame: Immediately after procedure

Patient Satisfaction

Single-item Likert scale (1-5, where 1 = very dissatisfied and 5 = very satisfied), recorded immediately after procedure by independent outcome assessor.

Time frame: Immediately after procedure

Amsterdam Preoperative Anxiety and Information Scale

Amsterdam Preoperative Anxiety and Information Scale (APAIS; 6 items; Moerman et al., Anesth Analg 1996;82: 445-451; Polish forward-backward translation). Administered before the procedure. Association with primary outcome assessed by Spearman correlation as covariate.

Time frame: Administered before the procedure.

NRS-Anxiety

NRS-Anxiety (0-10; single item: "How anxious are you right now?"). Administered before the procedure and immediately after biopsy sampling to assess pre-to-post procedural anxiety change. Pre-to-post delta reported as exploratory outcome.

Time frame: Administered before the procedure and immediately after biopsy sampling to assess pre-to-post procedural anxiety change.

TENS Amplitude vs Pain Reduction

Actual TENS amplitude used (mA) recorded for each participant in the active group. Spearman correlation between amplitude and NRS reduction during PNB.

Time frame: Intraoperative (active group only)

Pain Catastrophizing Scale (PCS-13)

Pain Catastrophizing Scale (Sullivan et al., Psychol Assess 1995;7:524-532). 13-item self-report questionnaire, score 0-52. Three subscales: rumination, magnification, helplessness. Polish version available. Administered before the procedure as covariate for primary outcome analysis.

Time frame: Before the procedure