A wide range of urologic procedures are performed using local or regional anesthesia. This includes an orchiectomy, inspection of the painful testis, release of a paraphimosis, dorsal slit, circumcision, and even a hydrocelectomy or varicocelectomy done in the Operating Room. Emergency Physicians can use some of the same anesthetic techniques, namely the penile or spermatic cord blocks, to safely and painlessly perform many procedures in the Emergency Department. These techniques are easy to learn, simple to perform, and have a low risk of serious complications.
ANATOMY AND PATHOPHYSIOLOGY
Innervation of the penis arises from the pudendal nerve that is derived from sacral levels 2 to 4. The pudendal nerve divides into the perineal and the inferior rectal nerves. The perineal nerve further divides into the right and left dorsal nerves of the penis. The dorsal nerves of the penis pass under the pubic symphysis to penetrate the suspensory ligament of the penis.1 They travel under Buck’s fascia to supply sensory innervation to the entire penis (Figure 177-1).
Transverse section through the base of the penis.
The primary nerve supply of the testis and epididymis is from the ilioinguinal and genitofemoral nerves. The ilioinguinal nerve is derived from the first lumbar spinal nerve. It arises slightly inferior and medial to the anterior superior iliac spine and courses toward the pubic tubercle between the internal and external oblique muscles.1,2 It enters the inguinal canal on the anterior surface of the spermatic cord. The ilioinguinal nerve provides sensory innervation to the skin of the upper thigh, base of the penis, and upper scrotum.1 It also provides sensory innervation to the spermatic cord and testicle. The genitofemoral nerve is derived from the first two lumbar spinal nerves. It divides into the genital branch and the femoral branch. The genital branch enters the inguinal canal at the external inguinal ring and travels with the spermatic cord. It provides sensory innervation to the lower scrotum, cremaster muscle, spermatic cord, and scrotum. The femoral branch supplies the skin of the anteromedial thigh.1
Emergency Department procedures that are facilitated by local anesthesia of the penis include a dorsal slit of the foreskin, release of a phimosis or paraphimosis, repair of penile lacerations, and release of penile skin entrapped in zippers. Local anesthesia can also be used before performing a circumcision. However, this procedure is usually not performed in the Emergency Department.
The Emergency Department indications for a spermatic cord block include the relief of epididymal pain, the facilitation of a manual or ultrasound examination when differentiating between torsion and epididymitis, and to inspect the testis following trauma. Manual detorsion of a testis may be enabled by local anesthesia when a patient cannot tolerate the ...