International Journal of Impotence Research (2005) 17, 471–473 & 2005 Nature Publishing Group All rights reserved 0955-9930/05 $30.00 www.nature.com/ijir

Case Report Alcock’s canal releasing for pudendal syndrome resulting from gunshot injury

B Seckin1, Y Kibar1*, S Goktas1 and F Erdemir1

1Department of Urology, Gulhane Military Medical Academy, Ankara, Turkey

A 21-y-old man applied to hospital with a complaint of erectile dysfunction, which started soon after a gunshot injury. The entry of the bullet was at the middle right gluteal region with- out any exit hole. A pelvic X-ray revealed the bullet and the scattered particles. On penile Doppler ultrasonography, the peak systolic velocities (PCV) of the right and the left cavernosal were 19 and 29 cm/s, respectively. Pudendal angiography revealed poor visualization of the right pudendal artery below the level of the bullet. The patient underwent a right-sided Alcock’s canal releasing surgery. After the operation, on control penile Doppler ultrasonography, PCV on the right and the left cavernosal arteries were 53 and 35 cm/s, respectively. The control angiography revealed a normal right pudendal artery. The patient was fully potent 2 y after the operation. Not only the entrapment of but also the pudendal artery may cause Pudendal canal syndrome. A gunshot injury may cause such a condition due to the reaction caused by the bullet. Pudendal canal decompression is a simple and effective treatment for pudendal canal syndrome. International Journal of Impotence Research (2005) 17, 471–473. doi:10.1038/sj.ijir.3901336; published online 5 May 2005

Keywords: Alcock’s canal releasing; erectile dysfunction; pudendal artery syndrome; gunshot injury

Erectile dysfunction (ED) has a multifactorial nat- Case report ure. ED can be caused by psychologic, neurogenic, hormonal and vascular disorders.1–3 Blockade of arterial supply in any level can cause ED.1 Normally, A 21-y-old man applied to hospital with a complaint the arterial blood supply to the corpus cavernosum of ED, which started soon after a gunshot injury and originates from the , leading to progressively deteriorated. At the first examination, the and terminating with the patient had no at all. No remarkable the penile and perineal arteries. The internal medical history, diabetes mellitus in particular, pudendal vessels and nerve run through the lateral medications or a previous surgery was recorded. wall of the ischiorectal fossa inside a fascial sheath, On physical examination, there was a bullet entry at the Alcock’s (pudendal) canal. Entrapment of the the middle part of the right gluteal region without pudendal nerve and artery in Alcock’s canal may any exit hole. A pelvic X-ray revealed multiple result in ED.1–3 As far as we know, this is the first opacities (Figure 1). Furthermore, a consultant case of pudendal artery syndrome (PAS) resulting neurologist excluded the presence of polyneuro- from a gunshot injury. pathy (diabetic, pharmaceutical/toxic, infectious or paraneoplastic). On penile Doppler ultrasonogra- phy, the corpora cavernosa and the corpus spongio- sum were normal on gray scale. After the intracavernous injection of 60 mg of papaverine, the right cavernosal artery diameter, which was 0.7 mm initially, increased to 1 mm. The peak *Correspondence: Y Kibar, Department of Urology, Gul- hane Military Medical Academy, Kardesler Koop. 2. Sok. systolic velocities (PCV) of the right and No. 12, Ankara 06010, Turkey. left cavernosal arteries were 19 and 29 cm/s, respec- E-mail: [email protected] tively. The angle was below 451 during Received 23 October 2004; revised 27 January 2005; the examination. Arterial insufficiency was consid- accepted 27 January 2005 ered to be the cause. The patient had perineal Alcock’s canal releasing for PAS B Seckin et al 472

Figure 1 Pelvic X-ray film reveals multiple opacities on the pelvic region (arrow).

hypoesthesia, weak anal reflex and EMG activity of the external anal sphincter, and prolonged bulboca- vernous reflex latency. The finding on anal sphinc- ter electromyography indicated a mild and partial axonal injury. The preoperative digital subtraction angiography (DSA) of the iliac artery revealed partial filling defect at the right distal pudendal artery and poor visualization of right distal . Bilateral cavernous arteries could not be observed (Figure 2a). Under the light of these findings, the patient underwent a right-sided Alcock’s canal releasing operation.1 With the lithotomy position the patient underwent general anesthesia. A vertical para-anal incision of 10 cm was made 2 cm lateral to the anal orifice. The ischiorectal fossa was exposed and the inferior rectal branch of the pudendal nerve was identified where it crosses the lower part of the fossa Figure 2 (a) Entering through the with Seldinger technique, the preoperative DSA of the iliac artery reveals partial lateromedially. Stretched by a hooked index finger, filling defect of the right distal pudendal artery (arrow) and poor the inferior rectal nerve was traced laterally to its visualization of right distal pudendal arteries. Bilateral cavernous origin from the pudendal nerve in the pudendal arteries cannot be observed. (b) The postoperative DSA of the iliac canal. The pulsation and increment in the diameter artery reveals normal appearance of the right pudendal (arrow) of the right penile artery was remarkable during the and cavernosal arteries. operation on releasing the canal. Pudendal neuro- vascular bundle was isolated and with its guidance the Alcock’s canal was released by incising the roof operation. He had signs of mild chronic partial of the canal. Some of the scattered particles were axonal degeneration on anal sphincter electromyo- removed, but the main bullet was not removed. graphy. Bulbocavernous reflex latency improved but Finally, the layers were anatomically closed. He- did not become completely normal at this time. The mostasis was secured and the wound was loosely end diastolic velocities on both sides were 0 (zero). closed to be self-drained. The patient has been followed for 2 y and he is fully The control pudendal angiography revealed a potent with no additional complaints for the time normal right pudendal artery (Figure 2b). At 3 being. months after the operation, the initial right caverno- sal artery diameter of 0.8 mm increased to 1.2 mm after intracavernous injection of 60 mg of papaver- Discussion ine. On this control penile Doppler ultrasonography, PCV on the right and the left cavernosal arteries were 53 and 35 cm/s, respectively. The patient still ED may result from the pudendal canal syndrome had perineal hypoesthesia 3 months after the due to entrapment of the pudendal nerve.1–3

International Journal of Impotence Research Alcock’s canal releasing for PAS B Seckin et al 473 Entrapment of the pudendal nerve may result from nerve is also important in penile erection. Contrac- levator subluxation and sagging.1,4 Levator sagging tion of bulbo- and ischiocavernosus muscles may pulls on and stretches the pudendal nerve. Contin- temporarily increase the corporal body pressure uous nerve stretch leads the pudendal nerve to be above the mean systolic pressure. edematous, with subsequent nerve compression impairment may lead to disorders of these muscle inside the canal, leading to nerve ischemia, which contractions with resulting ED.2 will add to the nerve damage. Eventually, entrap- Our case is different from Shafik’s case. In our ment neuropathy occurs. Either chronic constipa- case, ED resulted from the gunshot injury. However, tion leading to levator dysfunction in both sexes or the finding on anal sphincter electromyography repeated deliveries with a prolonged second stage indicated a mild and partial axonal injury as well, and forceps applications in females are the potential but the cause of ED in our case was primarily due to causes of this pathology.1,4 arterial insufficiency demonstrated by angiography. So far, there was only one study in the literature We think that neuronal factors could contribute to about PAS with ED.3 Shafik reported his experience the cause of ED in our case. The pulsation and with 10 patients with PAS. In his study, selective increment in the diameter of the right penile artery pudendal arteriography had shown narrowing was remarkable during the operation on releasing or obstruction of the distal part of the internal the canal support. pudendal artery on both sides with poor or As a result, we think that Alcock’s canal releasing nonvisualized penile arteries. We found similar is a simple, easy and effective operation in special findings in our case. Shafik showed that the cases due to PAS. improvement rates of ED were 80% (eight cases). He emphasized that the other two patients, who had pudendal arteriopathy combined neuropathy, did References not improve. Shafik described the mechanism and conse- 1 Shafik A. Pudendal canal syndrome: description of a new quences of entrapment of the pudendal nerves in syndrome and its treatment; report of 7 cases. Coloproctology detail. According to him, the pudendal nerve 1991; 13: 102–109. entrapment affects the dorsal nerve of the penis. 2 Shafik A. Pudendal canal compression in the treatment of The afferent pathway of the dorsal nerve provides erectile dysfunction. Arch Androl 1994; 32: 141–149. sensory information to the cerebral centers to 3 Shafik A. Pudendal artery syndrome with erectile dysfunc- tion: treatment by pudendal canal decompression. Arch allow for efferent re-activation via the autonomic Androl 1995; 34: 83–94. cerebral–sacral pathway to the pelvicavernous 4 Shafik A. A new concept of the anatomy of the anal sphincter nerve. Impairment of sensory afferent information mechanism and physiology of defecation, XVIII: the levator from the penile surface to cerebral centers may dysfunction syndrome; a new syndrome with report of cases. result in inability to re-activate the pelvicavernous Coloproctology 1983; 5: 158–165. 2,4,5 5 Ramsden CE et al. Pudendal nerve entrapment as a source of nerve. The other mechanism to explain the intractable perineal pain. Am J Phys Med Rehabil 2003; 82: cause of ED is the perineal nerve. The perineal 479–484.

International Journal of Impotence Research