Levels of evidence (1a-4) and grades of recommendation (A-C) are defined at the end of the "Major Recommendations" field.
Risk Factors
Risk factors associated with hypospadias are likely to be genetic, placental and/or environmental (Level of evidence: 2b):
- 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 pesticides).
The use of oral contraceptives during pregnancy has not been associated with an increased risk of hypospadias in the offspring (Level of evidence: 2a; Grade of recommendation; B).
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 (Level of evidence: 4; Grade of recommendation: C) (see Figure 1 in the original guideline document).
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 (Level of evidence: 4; Grade of recommendation: C). However, earlier repair between 4 and 6 months of age has been reported recently (Level of evidence: 3; Grade of recommendation: B).
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-vascularized 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) (Level of evidence: 3; Grade of recommendation: B).
Preservation of the Well-Vascularized Urethral Plate
The mainstay of hypospadias repair is preservation of the well-vascularized urethral plate and its use for urethral reconstruction has become the mainstay of hypospadias repair.
If the urethral plate is wide, it can be tubularized following the Thiersch-Duplay technique. If the plate is too narrow to be simply tubularized, 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.) (Level of evidence: 2b; Grade of recommendation: B).
If the continuity of the urethral plate cannot be preserved, a modification of the tubularized flap, such as a tube-onlay or an inlay-onlay flap, is used to prevent urethral stricture (Level of evidence: 3; Grade of recommendation: C). 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 (Level of evidence: 3; Grade of recommendation: C). 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 tubularized incised urethral plate (TIP) repair, the parents should be advised that use of a preputial dartos flap reduces the fistula rate (Level of evidence: 2; Grade of recommendation: B).
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.
Outcome
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 (Level of evidence: 2a).
Definitions:
Levels of Evidence
1a Evidence obtained from meta-analysis of randomized trials
1b Evidence obtained from at least one randomized trial
2a Evidence obtained from at least one well-designed controlled study without randomization
2b Evidence obtained from at least one other type of well-designed quasi-experimental study
3 Evidence obtained from well-designed non-experimental studies, such as comparative studies, correlation studies and case reports
4 Evidence obtained from expert committee reports or opinions or clinical experience of respected authorities
Grades of Recommendation
- Based on clinical studies of good quality and consistency addressing the specific recommendations and including at least one randomized trial
- Based on well-conducted clinical studies, but without randomized clinical studies
- Made despite the absence of directly applicable clinical studies of good quality
