Transrectal ultrasound guided needle electromyography of the urethral sphincter in males.

Needle electromyography (EMG) of the urethral sphincter in males is commonly performed using a transperineal approach. The technique involves transcutaneous insertion of an EMG needle into the sphincter guided by the investigator's finger placed in the rectum. We describe a new method of needle placement into the urethral sphincter in males using transrectal ultrasound (TRUS). With the patient in the left lateral position, the apex of the prostate gland is identified in the longitudinal plane. Using the TRUS biopsy channel, a specially designed long EMG needle is inserted into the sphincter commencing approximately 1.5-2 cm distal to the prostatic apex in an oblique fashion. This method allows precise identification of the site for needle insertion, reducing blind attempts at localization. The transrectal route is much less uncomfortable to patients, potentially improving patient compliance and overall effectiveness of the technique.