Hypospadias

CLASSIFICATIONS

Hypospadias can be defined as hypoplasia of the tissues forming the ventral aspect of the penis beyond the division of the corpus spongiosum. Hypospadias are usually classified based on the anatomical location of the proximally displaced urethral orifice:

- Distal-anterior hypospadias (located on the glans or distal shaft of the penis and the most common type of hypospadias)

- Intermediate-middle (penile)

- Proximal-posterior (penoscrotal, scrotal, perineal).

The pathology may be much more severe after skin release.

RISK FACTORS

Risk factors associated with hypospadias are likely to be genetic, placental and/or environmental :

- Endocrine disorders can be detected in a very few cases.

- Babies of young or old mothers and babies with a low birth weight have a higher risk of hypospadias.

- A significant increase in the incidence of hypospadias over the last 20 years suggests a role for environmental factors (hormonal disruptors and pesticide.

The use of oral contraceptives prior to pregnancy has not been associated with an increased risk of hypospadias in the offspring

Diagnosis Patients with hypospadias should be diagnosed at birth (except for the megameatus intact prepuce variant). 

Diagnosis includes a description of the local findings:

- Position, shape and width of the orifice

- Presence of atretic urethra and division of corpus spongiosum

- Appearance of the preputial hood and scrotum

- Size of the penis

- Curvature of the penis on erection.

The diagnostic evaluation also includes an assessment of associated anomalies, which are:

- Cryptorchidism (in up to 10% of cases of hypospadias)

- Open processus vaginalis or inguinal hernia (in 9-15%).

Severe hypospadias with unilaterally or bilaterally impalpable testis, or with ambiguous genitalia, require a complete genetic and endocrine work-up immediately after birth to exclude intersexuality, especially congenital adrenal hyperplasia.

Urine trickling and ballooning of the urethra requires exclusion of meatal stenosis.

The incidence of anomalies of the upper urinary tract does not differ from the general population, except in very severe forms of hypospadias

TREATMENT

Differentiation between functionally necessary and aesthetically feasible operative procedures is important for therapeutic decision-making.

The functional indications for surgery are:

- Proximally located meatus

- Ventrally deflected urinary stream

- Meatal stenosis Curved penis.

The cosmetic indications, which are strongly linked to the psychology of the parent or future patient’s psychology, are:

- Abnormally located meatus

- Cleft glans Rotated penis with abnormal cutaneous raphe

- Preputial hood Penoscrotal transposition

- Split scrotum.

As all surgical procedures carry the risk of complications, thorough pre-operative counselling of the parents is crucial.

The therapeutic objectives are to correct the penile curvature, to form a neo-urethra of an adequate size, to bring the neomeatus to the tip of the glans, if possible, and to achieve an overall acceptable cosmetic appearance of the boy’s genitalia. 

The use of magnifying spectacles and special fine synthetic absorbable suture materials (6/0-7/0) is required. As in any penile surgery, an exceptional prudence should be adopted with the use of cautery. Knowledge of a variety of surgical reconstructive techniques, wound care and post-operative treatment are essential for a satisfactory outcome. Pre-operative hormonal treatment with local or parenteral application of testosterone, dihydrotestosterone or beta-chorionic gonadotropin can be helpful in patients with a small penis or for repeat surgery.

AGE AT SURGERY

The age at surgery for primary hypospadias repair is usually 6-18 months. However, earlier repair between 4 and 6 months of age has been reported recently

PENILE CURVATURE

If present, penile curvature is often released by degloving the penis (skin chordee) and by excision of the connective tissue of the genuine chordee on the ventral aspect of the penis. The urethral plate has well-vascularised connective tissue and does not cause curvature in most cases. The residual chordee (curvature) is caused by corporeal disproportion and requires straightening of the penis, mostly using dorsal orthoplasty (modification of Nesbit dorsal corporeal plication).

PRESERVATION OF THE WELL-VASCULARISED URETHRAL PLATE

The mainstay of hypospadias repair is preservation of the well-vascularised urethral plate and its use for urethral reconstruction has become the mainstay of hypospadias repair .If the urethral plate is wide, it can be tubularised following the Thiersch-Duplay technique. If the plate is too narrow to be simply tubularised, it is recommended that a midline-relaxing incision of the plate, followed by reconstruction according to the Snodgrass-Orkiszewski technique, is performed in distal hypospadias, as well as in proximal hypospadias (though the complication rate is higher). The onlay technique is preferred in proximal hypospadias and in cases of a plate that is unhealthy or too narrow. For distal forms of hypospadias, a range of other techniques is available (e.g. Mathieu, urethral advancement, etc). If the continuity of the urethral plate cannot be preserved, a modification of the tubularised flap, such as a tube-onlay or an inlay-onlay flap, is used to prevent urethral stricture. In this situation, as well as in severe scrotal or penoscrotal hypospadias, the Koyanagi technique or two-stage procedure may be an option. If preputial or penile skin is not available, or has signs of balanitis xerotica obliterans, a buccal mucosa graft is used in an onlay or two-stage repair.The use of inlay skin grafts may allow an increased number of single-stage repairs to be performed

RE-DO HYPOSPADIAS REPAIRS

For re-do hypospadias repairs, no definitive guidelines can be given. All the above-mentioned procedures are used in different ways and are often modified according to the individual needs of the patient.

URETHRAL RECONSTRUCTION

Following formation of the neo-urethra, the procedure is completed by glansplasty and by reconstruction of the penile skin. If there is a shortage of skin covering, the preputial double-face technique or placement of the suture line into the scrotum may be used. In countries where circumcision is not routinely performed, preputial reconstruction can be considered. However, in the TIP repair, the parents should be advised that use of a preputial dartos flap reduces the fistula rate Urine drainage and wound dressing Urine is drained with a transurethral dripping stent, or with a suprapubic tube. Some surgeons use no drainage after distal hypospadias repair. Circular dressing with slight compression, as well as prophylactic antibiotics, are established procedures. A large variety of duration of stenting and dressing is described. No recommendation can be given due to the low level of evidence. Outcomes Adolescents, who have undergone hypospadias repair in childhood, have a slightly higher rate of dissatisfaction with penile size, but their sexual behaviour is not different from that in control subjects