Penile Hypospadias Reconstruction

Congenital malformations of male genitalia include a wide range of clinical situations such as hypospadias, epispadias (in the bifid clitoris) with bladder exstrophy, and hidden penis. This article addresses the surgical treatment of penile hypospadias.

The earliest report concerning urethral hypoplasia and its treatment dates back to Celsius (25 AD) and Galen (second century AD), with the description of hypospadias malformation. ^[1]

Duplay began the modern era in this field in 1874 by publishing a detailed procedure for urethra reconstruction. ^[1] Currently, more than 200 techniques have been described. Most of the procedures are multistage reconstruction; all consist of a first emergency stage that addresses correction of the stenotic meatus, if required, and a second stage that eliminates the chordee and the recurvatum.

Techniques differ regarding the third stage, the urethroplasty (creation of a neo-urethra and its coverage).

Numerous problems are associated with the multistaged techniques: they required multiple operations, the meatus often did not reach the tip of the glans or retract with time because of multiple tissue manipulations and repeated scarring, urethral stricture and/or fistula formation were frequent, and the final aesthetic result was poor.

To overcome the high frequency of complications, Hinderer introduced one-stage hypospadias repair in 1960.

Numerous modifications and innovative techniques were promulgated by other surgeons in the subsequent decade, all affirming the advantage of using unscarred tissue to reconstruct the urethra while minimizing the number of operations.

One-stage hypospadias repair claims ideal anatomic and functional urethral reconstruction, with good aesthetic restoration of external genitalia, a low complication rate, minor psychological involvement, and reduced social costs (see Figure 1 below).

Figure 1: History of hypospadias repair

Multistaged repairs

• The first stage addresses correction of the stenotic meatus if required.

• The second stage eliminates the chordee and the recurvatum.

• The third stage reconstructs a neo-urethra to the tip of the glans.

Milestones in urethroplasty ^[1]

• 1874: Duplay performed tubulization around a catheter of the ventral skin of the penis.

• 1897: Novè Josserand performed urethroplasty with a skin graft tubed around a catheter and anastomosed to the urethral meatus.

• 1899: Rochet performed tubulization of a meatus-based flap from the scrotum.

• 1917: Beck raised and tubed two paramedian ventral skin flaps.

• 1911: Ombredanne created a turnover flap harvested proximally to the meatus and sutured to two paramedian incisions performed distally to the meatus on the ventral penile skin.

• 1946: Denis Browne performed the buried skin stripe technique showing a spontaneous re-epithelialization of a neo-urethra around a catheter. ^[2]

One-stage repairs

• This involved correction of the recurvatum and reconstruction of the urethra in the same sitting.

• 1917: Beck performed a one-stage procedure for distal hypospadias with skeletonization and an advancement of the urethra to reach the tip of the glans.

• 1961: Horton and Devine performed a one-stage procedure, modified in 1967, which uses two flaps, one harvested from the glans and the other from the ventral penile skin, to reconstruct the urethra in distal hypospadias while a skin graft was suggested in the more proximal malformations.

• Hinderer in 1968, ^[3] Hodgson and Toksu in 1970, ^[4] Standoli in 1979, Duckett in 1980, ^[5] Scuderi in 1981, and Koyanagi in 1993 ^[6] performed a one-stage procedure based on using a preputial flap for urethroplasty.

Hypospadias consists of external urethral meatus dystopia, which may sort on the ventral surface of the penile shaft at any distance between the tip of the glans and the perineum, ventral absence of the preputium, and wide dorsal apron.

Curvature of the penile shaft and stenosis of the external meatus are often associated.

This malformation is seldom linked with genitourinary anomalies (eg, cryptorchidism, varicocele, hydrocele, ureteral duplication) and, rarely, with cardiovascular and craniofacial malformations.

Frequency

Hypospadias presents in 1 in 350 live male births in the United States and is the most frequent malformation of the genitourinary tract.

The enlargement of the genital tubercle and subsequent development of the phallus and urethra depend on the level of testosterone during embryogenesis.

If the testes fail to produce adequate amounts of testosterone or if the cells of the genital structures lack adequate androgen receptors or the androgen-converting enzyme 5 alpha-reductase, virilization is not complete and hypospadias results.

Genetic and nongenetic factors are involved in the etiology of hypospadias. A familial occurrence of hypospadias is found in approximately 28% of patients.

The exact genetic mechanism may be complicated and variable. The possibility of an autosomal dominance inheritance with low penetrance has been discussed. Another hypothesis is an autosomal recessive inheritance with incomplete manifestation.

Chromosomal aberration is found sporadically in patients with hypospadias.

Hypospadias is associated with several uncommon syndromes.

The main nongenetic factor associated with hypospadias is the administration of sex hormones; an increased incidence of hypospadias was found among infants born to women exposed to estrogen therapy during pregnancy.

Prematurity is associated more often in patients with hypospadias than in the general population.

The penis begins to form at approximately the fifth fetal week under the influence of testosterone. The urethral folds start to fuse over the urethral groove, and by the 14th week the process is complete (see image below). A short ingrowth from the tip of the glans progresses inward to meet the urethral tube at the fossa navicularis. The prepuce is then formed at the end of the development process.

Left: External genitalia during the undifferentiated stage. Middle: Male external genitalia at ninth week of intrauterine life. Right, from above to below: Transverse section of male genital area during the development of the urethral channel.

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Hypospadias occurs when the fusion of the urethral folds stops proximal to the tip of the glans penis and can occur anywhere along the urethral groove.

Severe forms of hypospadias are accompanied by shortening of the urethral groove, which causes ventral tethering of the penis, a condition termed "chordee."

This deformity presents with different severity according to the time of pathogen noxa during embryologic development. The meatus can sort in a glanular (60%), penile (35%), or scrotoperineal position (5%) and is clinically inadequate in 75% of patients and is often stenotic (see images below).

Distal hypospadias: spatulated glans, ventrally cleft preputium. (Published in Scand J Plast Reconstr Surg Hand Surg 1990; 24 (1): 67-73. Reprinted with permission of the editor.)

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Distal hypospadias. A traction suture is placed through the glans. Incision lines according to Scuderi repair: a coronal incision extended up to and around the meatus. (Published in Scand J Plast Reconstr Surg Hand Surg 1990; 24 (1): 67-73. Reprinted with permission of the editor.)

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The glans is often spatulated and the prepuce is cleft ventrally with a dorsally hooded foreskin (see images above). Penile curvature of different degrees is observed in many patients (45%).

Several urogenital defects are associated with hypospadias.

• Cryptorchidism (9%)

• Inguinal hernia (9%)

• Megalourethra, urethral fistulae, and hypoplastic testicles (reported less often)

• Upper urinary tract defects (observed in association with proximally located hypospadias)

See the list below:

• Meatotomy is indicated at any age when the meatus caliber is reduced, causing dysuria.

• Correction of glanular hypospadias with distal urethra repositioning, creation of a symmetric glans (glanuloplasty), and preputium plasty is indicated in childhood or adolescence at the patient's request for cosmetic or psychological reasons.

• Correction of penile and penoscrotal hypospadias is indicated in childhood in patients younger than school age for the following reasons:

  • To permit normalization of voiding

  • To allow normal erection and intercourse

  • To avoid urinary tract infections

  • To correct impotentia generandi and coeundi

  • To achieve cosmetic sexual identity

• Hypospadias is corrected by penile "chordee" resection and by creation of a urethra of adequate caliber and length (urethroplasty).

The two corpora cavernosa and the corpus spongiosum of the urethra with the glans form the penis.

These structures are made from erectile tissue surrounded by the tunica albuginea (Buck fascia) and by the dartos fascia more superficially, which contains terminal branches of external pudendal arteries and veins, pudendal nerves, and the superficial lymphatics (see images below).

The dartos fascia is outlined with the terminal branches of the external pudendal arteries and veins.

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Transverse section of the penis at midshaft level. From outside, the dartos fascia is visible with the blood vessels, the tunica albuginea surrounding the corpora cavernosa, and, in a ventral position, the urethra surrounded by its erectile tissue.

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The normal male urethra runs from the bladder through the penile shaft, ventrally to the corpora cavernosa, and sorts with the external urethral meatus at the tip of the glans.

Reconstruction of the urethra and restoration of the normal appearance of the genitalia is contraindicated in infancy because of the difficulty related to the small dimension of the structures.