The Corporo-Glans Ligament: Description and Functional Significance of a Ligament Connecting the Corpora Cavernosa to the Glans Penis

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The corporo-glans ligament: description and functional significance of a ligament connecting the corpora cavernosa to the glans penis

A Shafik1*, AA Shafik2, S Asaad3, M Wahdan4 and M Morris5

1Department of Surgery and Experimental Research, Cairo University, Cairo, Egypt; 2Department of Surgery and Experimental Research, Cairo University, Cairo, Egypt; 3Department of Histology, Cairo University, Cairo, Egypt; 4Department of Anatomy, Faculty of Medicine, Cairo University, Cairo, Egypt; and 5Department of Anatomy, Faculty of Medicine, Suez Canal University, Suez, Egypt

The two corpora cavernosa (CC) end blindly under cover of the glans penis (GP). The method of attachment of the CC to the GP could not be traced in the literature. The current communication investigated the hypothesis of a ligamentous attachment existing between the two corporal ends and the GP. In all, 18 male cadaveric specimens were studied by direct dissection and histologically. Six were neonates and 12 adults (mean age 32.3710.6 s.d. y). After examining and photographing the connection between the CC and GP, sagittal, parasagittal, and coronal sections of the connection were stained and studied microscopically. A triangular fibrous tissue band connected the distal blind ends of the two CC with the GP. The base of this band was attached to the tunica albuginea of the two CC, while the apex was continuous with the fibrous septa between the sinusoids of the cavernous tissue of the GP. Microscopically, the ligament consisted of collagen and elastic fibers; in some sections, the collagen fibers of the tunica albuginea were continuous with those of the band. A band of collagen and elastic fibers could be identified connecting the two CC to the GP; we term it the ‘corporo-glans ligament’. This ligament presumably affords the connection with rigidity, flexibility, and tissue strength. We suggest that it firmly connects the GP to the CC during penile thrusting. Further studies are required to assess the possible role of this ligament in erectile dysfunction. International Journal of Impotence Research (2004) 16, 220–223. doi:10.1038/sj.ijir.3901057

Keywords: tunica albuginea; cavernous tissue; erection; penile thrusting; erectile dysfunction

Introduction penis (GP).3 The method of attachment of the two corporal blind ends to the GP could not be traced in the literature. We hypothesized that a ligamentous The penis consists of three main parts: root, body, attachment is existing to link the blind ends of the 1 and glans. The root of the penis comprises the bulb two CC with the GP. The current communication and two crura. The two corpora cavernosa (CC) are investigated this hypothesis. bound together side by side with the corpus spongiosum to form the body of the penis. The corpus spongiosum and each of the two CC are surrounded by the tunica albuginea. The CC are Material and methods attached to the under-surface of the pubic symphy- sis by a triangular sheet of fibrous tissue called the suspensory ligament of the penis.2 The study comprised 18 male cadavers: six were The two CC extend along the penile body as two fully mature neonatal deaths and 12 were adults rods which end blindly under cover of the glans varying in age from 16 to 48 y (mean 32.3710.6 s.d.). They were preserved in 10% formalin for 5–7 days. The specimens consisted of the body of the penis *Correspondence: A Shafik, PhD, Professor and Chairman, including the glans penis. The connection of the 2 Talaat Harb Street (A092), Cairo 11121, Egypt. distal end of the two CC to the GP was studied by E-mail: ashafik@ ahmedshafik.org direct dissection using a magnifying loupe, bright Received 19 February 2003; revised 27 May 2003; light, and fine surgical instruments. The penis was accepted 14 June 2003 degloved by means of a circumferential incision Corporo-glans ligament A Shafik et al 221 performed at the junction of the GP with the penile surrounding the penile body (Figure 2). In some body. After exposure of the two CC, dissection sections, it was apparent that the collagen fibers of proceeded to expose their distal ends under the the band were direct extensions of those of the cover of the corona of the GP. The corona was tunica albuginea (Figure 3). The lateral borders retracted forward and the method of attachment of of the band merged with the cavernous tissue of the distal ends of the two CC to the GP was the GP. The apex extended in the distal part of examined and photographed. Histologic examina- the GP, where it sent out side branches that were tion of the connection between the two CC and the continuous with the fibrous septa between the GP was done by taking sagittal, parasagittal, and sinusoids of the cavernous tissue of the GP (Figures coronal sections through the specimens including 1, 2, 4). An apparent relation could not be defined the connection. Serial blocks were made and between the corporo-glans ligament and the struc- sections of 7 mm thickness were cut at multiple tures located in the dorsal aspect (superficial and levels and stained with hematoxylin and eosin, deep dorsal veins, deep arteries, and nerves) of the Masson’s trichrome, and orcein stains. penis. Microscopic examinations have shown that the band consisted of collagen fibers impregnated with elastic fibers (Figure 5). The collagen fibers were Anatomic findings more abundant near the attachment of the band to the tunica albuginea of the CC, while the elastic Gross examination of the corporo-glans junction showed the presence of a fibrous tissue band which connected the distal blind ends of the two CC with the GP (Figures 1, 2). The corporal end lay in a socket embedded in the GP (Figure 1). The fibrous band was triangular in shape and measured 0.3– 0.5 cm in length and 0.2–0.4 cm in breadth in neonates, and 0.75–1 cm in both length and breadth at the base in adults. Its base was attached to the tunica albuginea covering the distal round ends of the two CC (Figures 1, 2). We found that, in 16/18 cadaveric specimens, the tunica albuginea at the site of attachment to the band was thicker than that

Figure 3 Parasagittal section in glans penis showing the triangular corporo-glans ligament (orcein Â 6). CC: corpus cavernosum; TA: tunica albuginea; L: corporo-glans ligament; GP: cavernous tissue of glans penis. The ligament appears to be a direct extension of the tunica albuginea.

Figure 1 Sagittal section of the penis showing the corporo-glans ligament (magnification Â 2). CC: corpus cavernosum; TA: tunica albuginea; GP: glans penis; L: corporo-glans ligament. Observe the fibrous extensions from the apex of the ligament into the cavernous tissue of the glans penis.

Figure 2 Parasagittal section of the penis showing the corporo- glans ligament (magnification Â 2). CC: corpus cavernosum; TA: tunica albuginea; GP: glans penis; L: corporo-glans ligament. The Figure 4 Coronal section of the distal end of the glans penis blind end of the corpus cavernosum is embedded in the glans away from the two corpora cavernosa (orcein Â 6). GP: glans penis. penis; L: corporo-glans ligament.

International Journal of Impotence Research Corporo-glans ligament A Shafik et al 222 albuginea, as evidenced from the continuity of the fibers of the tunica albuginea into the ligament in some of the studied sections. The fibrous extensions of the apex of the ligament being continuous with the fibrous septa between the sinusoids of the GP appear to provide a firm attachment of the distal end of the ligament to the GP. It is thus suggested that the main function of that ligament is to secure a firm connection between the GP and the distal end of the two CC, in particular during penile thrusting. Furthermore, since the corporo-glans ligament seems to be a direct extension of the tunica albuginea, and as Peyronie’s disease is primarily a disease of the tunica albuginea, we suggest that the ligament might be involved Figure 5 Photomicrograph of the corporo-glans ligament show- in Peyronie’s disease, possibly leading to distal ing collagen fibers impregnated with elastic fibers (orcein Â 100). penile or glans curvature. However, this point needs to be studied. The histologic structure of the corporo-glans fibers were more condensed close to the apex of the ligament seems to assist in its functional adapt- band. The collagen fibers of the band were contin- ability. Thus, the elastic fibers contained in the uous with those between the GP sinusoids. ligament lend it a degree of flexibility during penile thrusting. On the other hand, the collagen fibers of the ligament presumably keep it tight and secure Discussion the firmness of the connection between the ligament and the GP. We do not know the exact role of the corporo- The penis consists of two CC and one corpus glans ligament in erectile dysfunction. We spec- spongiosum. The CC are supported by a fibrous ulate, however, that its possible subluxation may skeleton that includes the tunica albuginea, intra- disturb the connection between the GP and the two cavernous pillars, the intracavernous fibrous net- CC, and hence interfere with adequate penile work, and the periarterial and perineural fibrous thrusting. In such cases, the GP may appear flobby sheath.4,5 The intracavernous framework appears to and too mobile, especially after erection; it shows add significant strength to the tunica albuginea.6,7 hypermobility over the end of the erected rigid CC. The fibrous sheaths of the corpora are fused together This seems to be due to corporo-glans ligament in a manner that allows the three corpora to act as subluxation. The hypermobile GP or glans bowing one unit during erection and penile thrusting.5 was reported to occur over the end of the penile However, the tunica albuginea of the corpus spon- prosthesis;11 we believe that this bowing results giosum is thinner and less tough compared with from ligament disruption induced by the distal ends the tunica albuginea of the CC.1 Furthermore, the of the prosthesis perforating the CC and injuring the issue of the tunica albuginea covering the GP is ligament. controversial because some investigators deny its The impact of the different surgical techniques on presence.8 the corporo-glans ligament needs to be considered. The distal ends of the two CC are embedded in a Surgical procedures dissecting the ligament off the socket in the GP. During erection, the two CC and the two corporeal ends should include ligament recon- corpus spongiosum are congested including the GP. struction as a part of the technique to prevent During penile thrusting, the rigid corporal ends interference of the bowing glans with penile thrust- embedded in the GP act to push the glans forward ing. This point needs to be studied. into the vagina.9,10 They impart rigidity to the soft In conclusion, we could identify a corporo-glans congested GP during vaginal penetration and penile ligament connecting the two CC to the GP and thrusting. presume that it affords the connection with rigidity, In the current study, we could define a band that flexibility, and tissue strength. We suggest that the connects the distal ends of the two CC to the GP. It ligament firmly connects the GP to the CC during consisted of collagen and elastic fibers, and we term penile thrusting, and postulate that its functional it the ‘corporo-glans ligament’. The broad base of disorder would interfere with proper penile thrust- this triangular ligament and its attachment to a ing. Further studies are required to assess the thickened part of the tunica albuginea at the distal possible role of this ligament in erectile dysfunction end of the CC are supposed to give firmness to the and Peyronie’s disease. The impact of the surgical ligamentous attachment. Meanwhile, it seems that techniques on the corporo-glans ligament also needs the ligament is a direct extension of the tunica to be considered.

International Journal of Impotence Research Corporo-glans ligament A Shafik et al 223 Acknowledgements 4 Goldstein AMB, Padma-Nathan H. The microarchitecture of the intracavernosal smooth muscle and the cavernosal fibrous skeleton. J Urol 1990; 144: 1145–1146. Margot Yehia and Waltraut Reichelt assisted in the 5 Hsu GL et al. The three-dimensional structure of the human tunica albuginea: anatomical and ultrastructural levels. Int J preparation of this manuscript. Impotence Res 1992; 4: 117–119. 6 Bitsch M, Kromann-Andersen B, Schou J, Sjontoft E. The elasticity and the tensile strength of tunica albuginea of the corpora cavernosa. J Urol 1990; 143: 642–644. References 7 Tamaki M. Mechanism preventing backflow from the canine corpora cavernosa to arteries in the rigid phase of penile erection. Urol Unt 1992; 48: 61–70. 1 Jordan GH, Schlossberg SM, Devine CJ. Surgery of the penis 8 Goldstein AMB et al. New observations on the micro- and urethra. In: Walsh PC, Retik AB, Darracott Vaughan Jr E, architecture of the corpora cavernosa in man and possible Wein AJ (eds) Campbell’s Urology, 7th edn WB Saunders relationship to mechanism of erection. Urology 1982; 20: Company: Philadelphia, 1998, pp 3316–3394. 259–266. 2 McMinn RMH. Male urogenital region. In: McMinn RMH (ed) 9 Shirai M et al. Hemodynamic mechanism of erection in the Last’s Anatomy: Regional and Applied, 8th edn. Churchill human penis. Arch Androl 1978; 1: 345–349. Livingstone: Edinburgh, 1990, pp 406–412. 10 Andersson K-E, Wagner G. Physiology of penile erection. 3 Lue TF, Zeineh SJ, Schmidt RA, Tanagho EA. Neuroanatomy Physiol Rev 1995; 75: 191–236. of penile erection: its relevance to iatrogenic impotence. J Urol 11 Stefani SD et al. The benefit of glans fixation in prosthetic 1984; 131: 273–280. penile surgery. J Urol 1994; 152: 1554–2533.

International Journal of Impotence Research