2010, Number 3
Rev Mex Urol 2010; 70 (3)
Effectiveness comparison of transperineal pudendal nerve block as anesthesia method in transrectal ultrasound-guided prostate biopsy
Venegas-Ocampo PJJ, Castillo-De Lira HH, Robles-Scott MA, Landa-Soler M, López-Mariscal MC, Mendoza-Peña F, Velázquez-Macías R
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ABSTRACTIntroduction: The pudendal nerve is responsible for afferent stimulation of the anorectal region. Knowledge of pudendal nerve anatomy is essential for pudendal nerve block. Transrectal prostate biopsy is the most common procedure used in cancer detection and numerous researchers have reported that from 10-40% of patients experience no pain when it is performed. However, a large number of studies have shown that patients find this procedure extremely painful. In Mexico transrectal biopsy is performed as an outpatient procedure in the majority of urological centers and finding a satisfactory method of pain control for these patients is considered necessary.
Methods: A total of 60 transrectal ultrasound-guided prostate biopsies were carried out on consecutive patients with prostate specific antigen (PSA) above 4 ng/mL, or suspicious digital rectal examination (DRE). From February first to May thirtieth of 2009, 56 patients were included in the present study based on inclusion criteria. They were randomly distributed into two groups of 29 (n = 29) and 27 (n = 27) patients. The anesthesia method used in the group of 29 patients was bilateral block of the pudendal nerves through perineal approach. Topical rectal anesthesia was applied to the group of 27 patients combined with oral analgesia with paracetamol. All patients were given a prophylactic quinolone antibiotic. Patients completed a visual analogue pain scale from 0 to 10 immediately after biopsy so that later comparison of the different biopsy stages (transrectal transducer introduction and needle punctures of the prostate during biopsy) could be made and the pudendal nerve block could be evaluated.
Results: Mean age was 66.93 ± 7.85 years, PSA level was 20.43 ± 35.79 ng/mL and prostate volume was 54.77 ± 21.82 in the pudendal nerve block group. Mean age was 67.33 ± 8.94 years, PSA level was 11.29 ± 5.07 ng/mL and prostate volume was 47.07 ± 18.45 in the topical rectal anesthesia and oral analgesic group. Mean number of core samples was 12 in both groups. Pain upon ultrasound transducer introduction was 1.21 ± 1.47 in the pudendal nerve block group and 3.48 ± 1.89 in the topical rectal anesthesia and oral analgesic group (P ≤ 0.001). Mean pain from needle puncture of the prostate was 1.93 ± 1.39 in the pudendal nerve block group and 3.78 ± 1.28 in the topical rectal anesthesia and oral analgesic group (P ≤ 0.001). Discomfort felt by patients during pudendal nerve block was 1.00 ± 0.96 with a 0-3 range.
Conclusions: In the group of patients studied, bilateral pudendal nerve block was shown to be an effective, quick and reliable method to be carried out by the urologist in outpatient transrectal prostate biopsy allowing the procedure to be carried out with ease for both the patient and the physician.