//Hypospadias surgery : when, what and by whom ?
Hypospadias surgery : when, what and by whom ?2017-04-05T18:51:37+00:00

Hypospadias surgery : when, what and by whom ?

 

pdf chirurgia uretrale

Authors:
Enzo Palminteri et Al.

Publication:
BJU  INTERNATIONAL

Volume:
94, 1188–1195

Centre:
Center for Urethral and Genitalia Reconstructive Surgery, Arezzo, Italy.

 

 

Summary

Hypospadias repair is undertaken by paediatric surgeons, paediatric urologists, adult reconstructive urologists, and plastic surgeons. This collaborative publication is unique in representing all four specialties, to provide a unified policy on the management of hypospadias.
The surgeon, from whichever specialty, should have a dedicated interest in this challenging work, ideally having an annual throughput of at least 40-50 cases.
The authors conclude that an ideal time for primary repair is at 6-12 months of age, though when this is not practicable there is a second window of opportunity at 3-4 years of age. A modern surgical protocol is presented which places emphasis on both functional and cosmetic refinement. Use of a simple and logical progression of a very few related procedures, allows for reliable correction of almost any hypospadias deformity.

 

Introduction

Hypospadias is one of the most common malformations of male genitalia, with a traditionally quoted incidence of 1 in 300 male births. However, epidemiological evidence suggests that in developed Western countries the incidence is increasing [1], and may be as high as 8 in 1000 male births. Both genetic and environmental factors are implicated in the aetiology and numerous theories have been proposed about both the causation and the changing prevalence [2-4], but discussion of these falls outside the remit of this paper.
There is no single satisfactory way of classifying hypospadias. Despite obvious limitations, pre-operative meatal position remains the most commonly used criterion. By this classification, at least 70% of hypospadias is either glandular or distal penile, 10% mid penile, and 20% more severe proximal types.
Table 1 and Figure 1 summarises the principal anatomical variables associated with the spectrum of hypospadias severity, and lists the expected findings. Unfortunately hypospadias deformities do not necessarily conform to these expectations, so this is only a broad generalisation. Position of the meatus alone is therefore not a reliable indicator of hypospadias severity as far as choice of appropriate surgical correction is concerned. Occasionally a distal hypospadias may have severe curvature with a poorly developed urethral plate and glans groove, whilst a proximal hypospadias may have the opposite features.
Our proposed surgical protocol is determined more by these other anatomical variables, in particular the quality of the urethral plate, the glans configuration, and degree and type of curvature. This has allowed the confusing and vast array of available repairs to be narrowed down to a simple and logical progression of just a few related procedures.

 

Preoperative evaluation

Hypospadias is generally an isolated anomaly but it may represent one of the features of over 200 different syndromes [5]. Associated malformations of the urinary tract are most common in proximal or complex hypospadias, but their incidence in distal forms is not different from that of the general population. Table 2 summarises the most frequently encountered anomalies. It is therefore not necessary to undertake formal investigation of the urinary tract for simple distal hypospadias, unless associated with unexplained symptoms. Proximal hypospadias however requires a more thorough pre-operative evaluation. If one or both testes are impalpable, it may signify the presence of an intersex condition such as adrenogenital syndrome or a mixed gonadal dysgenesis. In this instance, a karyotype study and an ultrasound study of the urinary tract and internal genital organs should be always performed [6].
Furthermore, endoscopic examination of the urethra at the time of surgery is necessary to rule out the presence of a Mullerian remnant (dilated utriculus). Accurate assessment of the type of hypospadias, with regard to severity of curvature and the urethral quality, is often possible only with the patient under anaesthesia, and this may therefore lead to modification of the surgical plan.

 

Timing of surgical repair

Whenever possible it is helpful to assess the problem during the first few weeks of life. This reduces the parental guilt and fear of the unknown that is typically associated with congenital birth defects, whilst at the same time establishing a bond between the parents and the surgeon that is instrumental to future management.
Factors that can influence the timing of hypospadias repair include the environment in which the patient will be managed, anesthetic risk, penile dimensions and the psychological effect of genital surgery. After the age of 6 months the risk of anesthesia is no greater than at a later age [7] provided the anesthesia is administered by a specialist paediatric anesthetist and the patient cared for in a designated paediatric facility. Penile size is not a limiting factor in most children and since only moderate penile growth occurs in the first few years of development, there is no technical advantage in delaying surgery. At 1 year of age penile length is, on average, only 0.8 cm shorter than at pre-school age [8]. With a very small phallus, use of hormonal stimulation to achieve penile enlargement is now less controversial, because initial concerns about subsequent down-regulation of androgen receptors appear to be unfounded. Testosterone enanthate (25mg) administered intra muscularly 1 month before surgery or topical di-hydro-testosterone cream, applied daily for 1 month, are both viable options [9].
Genital awareness does not begin until 18 months of age. This also heralds the start of a difficult and uncooperative behavioural phase in the child’s development, which makes him ill suited to hospitalisation. It is not until the age of 3 years that the child becomes sufficiently mature to collaborate with his treatment, and this then presents a second window of opportunity for primary hypospadias repair. This pre-school period, age 3-4 years, is a more workable option for those surgeons who do not practise in a specialised paediatric facility, and seems to produce similar outcomes to those of surgery undertaken during the first year of life.
Recommendations from the Section of Urology of the American Academy of Pediatrics now suggest that the optimal time for elective surgery on genitalia is either in the second six months of life or sometime during thefourth year. [10,11] We therefore conclude that where practical, the ideal time to correct primary hypospadias is between the age of 6 – 12 months.

 

Surgical treatment

Modern surgical repair of hypospadias requires an experienced dedicated specialist, whether a paediatric urologist/surgeon, a plastic surgeon, (or an adult reconstructive urologist). This is not surgery for the occasional operator, therefore a throughput of at least 40 to 50 cases per year is desirable.
With advances in surgical techniques and suture materials, use of optical magnification and microsurgical instrumentation, hypospadias repair has evolved into a safe and reliable procedure with a very high reported success rate. Dedicated paediatric facilities and paediatric anaesthetic support are essential to the success of short stay surgery in very young children. A further requirement is the routine use of intra-operative caudal or penile local anaesthetic blocks as part of an effective post-operative analgesic regime. In first world countries the trend is towards earlier intervention with ever-shorter hospitalisation; indeed in many centres the norm is now for a single-stage repair undertaken as a day-case during the first year of life. The purpose of this is not merely a cost cutting exercise, but also has the potential benefit of reducing the psychological impact of surgery and the separation anxiety that may be associated with hospitalisation. Early, day–case repair may be a safe, realistic and desirable prospect when sophisticated surgery and anaesthesia can be combined with high standards of community aftercare. It should be recognised however that in many parts of the world, even in developed countries, this ideal cannot be achieved for a variety of reasons, therefore pre-school surgery and longer periods of hospitalisation may still be preferred.
Patient co-operation is not a requisite in very young infants, and an open system with a dripping stent and double diaper method of dressing will adequately contain the urine drainage and also prevent the child from interfering with the operation site. A wide lumen indwelling silicone Foley catheter is preferred in the older patient, ranging from 8F in a childthrough to 12F in an adult. These days, supra-pubic diversion is seldom justified.
The choice of dressings, use of prophylactic antibiotics and decisions about urinary diversion are not universally agreed. These remain areas of individual surgeon preference, influenced by the severity of the hypospadias and the type of repair employed.

 

Selecting the surgical procedure

The goal of primary hypospadias repair is to achieve both cosmetic and functional normality. Whether this is achieved in a single procedure or with a staged approach, it requires the creation of a straight penis, with an even calibre neo-urethra terminating in a natural slit-like meatus at the apex of a naturally reconfigured glans.
Ironically the very distal forms, which account for the vast majority of hypospadias, are sometimes the most challenging in terms of the decision making process, because cosmesis is often the only real indication for treatment. Foreskin preservation and reconstruction may be an issue because of local cultural pressures or parental preference, and when the penile skin configuration allows for this, then the prepuce can be successfully reconstructed [12,13,14]. However, there is still as yet no published long-term data concerning the sexual function of these reconstructed foreskins.
At the other end of the spectrum, perineal hypospadias represents the most challenging and technically demanding surgical exercise, involving both urethral reconstruction and correction of penile curvature and variable degrees of peno-scrotal transposition. No attempt should be made to underscore the complexity of hypospadias repair, and the benefits of correction should always outweigh the potential risks. The choice of technique is determined by the anatomical characteristics previously described (Fig. 1). Despite the huge number of reconstructive techniques now available, the authors feel that a simple and reliable protocol can be applied mostly based on the quality and development of the urethral plate, rather than the pre-operative location of the meatus.

 

1-stage repair

  • urethral plate tubularisation (GAP, Snodgrass)
  • urethral plate augmentation ( onlay flap, “Snod-graft”)

2-stage repair

  • urethral plate substitution (Bracka)

 

Urethral plate tubularisation

When the urethral plate does not require transection and its axial integrity can be maintained, it is possible to tubularise it. Occasionally, when the plate is of adequate width and depth, it can be tubed directly as described by Zaonz (GAP procedure)[15]. Conversely, when the plate is not adequately developed and requires width/depth enhancement before it can be tubed, the addition of a midline deep dorsal releasing incision is performed according to the Snodgrass procedure [16]. This tubularised incised plate (TIP) repair was first described in 1994, and has gained worldwide popularity as a solution for distal primary hypospadias, but it has subsequently also gained acceptance for suitable proximal forms of hypospadias and, more recently, for selective use in re-operations [17].Initial concerns regarding the potential for stricture development have not been substantiated, at least in the short-term, and the Snodgrass repair is currently providing superior cosmetic and functional results compared to other techniques. (Fig. 2)

 

Urethral plate augmentation

Despite the potential enhancement of width with the midline releasing incision, there are occasionally narrow and inelastic urethral plates that require more substantial augmentation. This can apply to distal hypospadias, but more particularly to severe penile forms where the application of an extended Snodgrass procedure may generate concerns for the long-term outcome. The onlay preputial island flap, as popularised by Duckett [18] can be performed in the vast majority of these cases and for many surgeons still represents an ideal solution. However, a more recently developed and increasingly popular concept is the “Snod-graft” repair. This represents a logical progression of the original Snodgrass principle, wherein a free graft is quilted into the dorsal defect rather than leaving it to epithelialise.
This is a useful procedure when the glans configuration is more conical, with a minimal groove and lacking the usual external rotation of the glans wings. To achieve an apical meatus would in this instance necessitate extension of the Snodgrass dorsal releasing incision beyond the distal limit of the glans groove and thereby invite a meatal stricture, unless the defect is grafted. The “Snod-graft” concept is particularly useful in redo salvage cases and is further discussed in the section on hypospadias failures. Urethral plate substitution In the presence of severe proximal forms, with significant ventral chordee, urethral plate transection becomes inevitable, and a full circumference substitution urethroplasty is then required. Single stage tubularised repairs, the most popular being the Duckett TPIF [19], have been largely abandoned because of their prohibitive long-term complication rate.
A 2-stage procedure such as described by Bracka [20] is regarded by many as a better option. For primary cases the inner preputial skin layer is used as a free full thickness (Wolfe) graft (Fig. 3). If the prepuce is poorly developed or absent because of circumcision, then buccal mucosa or non-genital skin can be used either in addition to prepuce or as an alternative to it. This allows for optimum release of ventral chordee tissue and penilelength preservation. Remaining inherent corporeal disproportion may however still require correction by a dorsal Nesbit procedure. When this would lead to unacceptable shortening of an already hypoplastic organ, consideration may be given to ventral tunica release and lengthening with dermal or tunica vaginalis grafts [21,22]. In the absence of any published long-term data however, some caution is required, because erectile dysfunction is a well recognised complication in adults who undergo tunica-grafting procedures for curvature correction.

 

Follow-up protocol

Traditional thinking has been that any significant complications will have presented within the first two years after surgery and therefore follow-up beyond this time is not cost effective use of scarce resources. It is assumed that patients will themselves seek review for the few problems that may arise later on. Early discharge has also been justified on the grounds that it is best to let the patient forget that he had a genital abnormality; as repeatedly bringing the fact to his attention might actually generate psychological concerns. Evidence from adult studies quoted below, clearly refutes these assumptions and shows that early discharge is just a convenient way to “sweep problems under the carpet” and allow for flattering “re-operation rates” which bear little relation to the true complication rate.
An ideal protocol should include an early evaluation within 3 months of surgery, followed by a review at 1or 2 years, and again at 4 or 5 years. The quality of micturition should be assessed subjectively, and when possible confirmed objectively with uroflowmetry and perhaps a bladder pre and post-micturition ultrasound evaluation. With the onset of rapid growth at puberty there is potential for new problems to arise; a previously unrecognised and asymptomatic microfistula might start to leak; a scarred neo-urethra may fail to grow adequately, or the shape of the penis may cause concern. The patient should therefore be reassessed at puberty and again at around mid-teens, by which time genital maturation will be at or near completion and the patient is able to comment about social and sexual aspects of the penile surgery.

 

Hypospadias failures – more often than we think?

Using the above protocols to repair primary hypospadias, early “re-operation” rates of below 10% are a realistic goal. However, disconcerting evidence from adult review studies [23], suggests that the true long-term complication or dissatisfaction rates may be significantly higher.
The landmark study by Mureau et al [24] found that, almost 50% of the adolescents they reviewed were prepared to consider further surgery if their penises could be made to look more normal. Interestingly, they found that there was no statistical difference in subsequent social and sexual adjustment between those having single stage repairs in the first year of life and those having 2-stage surgery at around school age. In other words, what really determines patient satisfaction is the quality of functional and cosmetic outcome rather than the means by which it is achieved.
Unfortunately, despite the compelling evidence, few hypospadias centres actively follow up their patients. Instead the responsibility is placed with the family to request a review appointment if and when problems arise, or when the boy reaches maturity. The large adult review study by Bracka [25] shows this to be a naïve policy. Approximately half the patients in that study took up the opportunity to have their hypospadias repairs surgically revised, even though they had originally been discharged in childhood with apparently satisfactory outcome. Had it not been for the request to return for review, few of these young adults would have sought help of their own initiative, either because of embarrassment, resignation or ignorance that further improvement was possible.
It is probable that today’s more sophisticated repairs will not reproduce quite the same alarming rates of late dissatisfaction. AB has now followed several hundred of his 2-stage repairs through to genital maturity and is heartened to encounter very few late concerns with either function or cosmesis. Urethras created from free preputial grafts grow just as well as those created from flaps, but we still know relatively little about the long-term behaviour and growth of less androgen sensitive tissues such as buccal mucosa. There is as yet no long-term data on the Snodgrass repair, and there are still other unresolved issues to document, such as the late outcome of childhood Nesbit procedures or of foreskin reconstruction. Until this information becomes available we should maintain an active long-term follow-up policy, both for our education and for the patients’ welfare.

 

Complications – early and late.

Patient dissatisfaction may be wide ranging.

1. Urinary dysfunction:
A) Obstructive-irritating symptoms +/- recurring infections due to: strictures, diverticulae, urethral stones and hairs.
B) Misdirection or spraying of the urinary stream due to: ectopic or misshapen meatus, stricture or fistula.
C) False incontinence (post-micturition dribbling) due to megalo-urethra or diverticulum.

2. Sexual dysfunction:
A) Difficult penetration due to: residual chordee, restricting or deforming scars, penile hypoplasia.
B) Poor ejaculation due to: urethral stricture, dilatation or diverticulum.

3. Appearance:
A) Abnormal glans and meatus configuration, prominent scarring and skin asymmetry, are inherent to many types of repair.
B) Absence of foreskin may cause self-awareness in some communities.
C) Short penis, bifid or abnormally inserted scrotum; these are often associated with proximal hypospadias.
In older patients, the perception of an abnormal penis can lead to “Locker-room syndrome” and reluctance to pursue sexual relationships. Further to correcting any residual hypospadias deformities, body image counselling and sympathetic consideration for penis lengthening procedures may also be appropriate.

 

Investigations

Sometimes taking an adequate history and examination may be sufficient to determine the problem and to recommend appropriate management. For instance, a long unexplained history of recurring or late onset strictures should immediately raise the suspicion of balanitis xerotica obliterans (lichen sclerosus). The clinical findings of an indurated neo-urethra with typical white discoloration and fibrosis around the meatus make the diagnosis almost beyond doubt, but for absolute certainty it can then be confirmed by histological biopsy.
Pre-operative urinalysis and uroflometry, together with detailed investigation of the lower urinary tract using retrograde and voiding cysto-urethrography and urethroscopy, provide important information about urinary dysfunction. This information is valuable not only for determining appropriate treatment, but also as a tool to help explain and justify the proposed management to the patient. These investigations may determine the presence, severity and extent of abnormalities of the neo-urethra such as stricture, diverticulum, hairs, stones, and dysplasia/neoplasia. They may also bring to light an unrecognised and unrelated proximal stricture, or a prostatic utricle, both of which may cause unexpected difficulties with catheterisation (Fig 4)

 

Management

One of the authors (AB) has treated hundreds of disgruntled teenagers and adults with failed hypospadias repairs, many of whom have been in and out of hospital ever since early childhood and have lost all faith in the medical profession. Spending quality time addressing their socio-sexual concerns and aspirations, in addition to providing adequate clinical information about the salvage surgical options, is an essential part of the trust building and rehabilitation process. Some surgeons may delegate part of this process to a sympathetic body image counsellor or clinical psychologist.
The principles of salvage surgery are not dissimilar to those already described for primary repair, but faced with already scarred, less vascular and perhaps deficient tissues, this surgery is often a greater technical challenge and not surprisingly carries a somewhat higher complication rate. Post-operative erections can be distressing or disruptive in the older patient, and this trauma can be reduced by the use of peri-operative anti-androgen therapy or topical cold sprays [20].

 

1-stage redo surgery

As with primary hypospadias repair, when the axial integrity of the neo-urethra can be maintained for at least part of its circumference (for instance fistula repair, urethral reduction or augmentation stricture-plasty), then repair can be safely effected in a single operation.
Simple fistula repair is usually successful provided that there is no associated problem with the calibre of the urethra, and that attention is paid to separation of suture lines. This can be achieved either by interposing a dartos fascia “waterproofing” flap between urethra and skin, or using advancement or rotation of skin flaps to offset the skin closure. Whilst the Snodgrass TIP repair has revolutionised the primary correction of hypospadias, it is less well suited to redo urethral augmentation.
Firstly one is likely to be incising into previously operated, less vascular tissues that will therefore have a greater propensity to heal by contraction and scarring. Furthermore whilst the size of the dorsal wall defect may be proportionately the same as for primary repair, in absolute terms the size of defect that is required to re-epithelialise will be much larger in an adult penis. The problem is overcome by quilting a free graft of buccal mucosa (or inner preputial skin if still available) into the dorsal defect [26-29], thereby creating a graft augmented Snodgrass or “Snod-graft” repair. (Fig 5).
Free augmentation grafts in the adult penile urethra should be placed as dorsal inlays rather than ventral onlays, because the ventral soft tissues of a hypospadic penis provide poor vascular and mechanical support for a free graft. Ventral onlay would therefore result in a greater likelihood of graft failure, fistula formation or urethral dilatation.

 

2-stage redo surgery

When a full circumference substitution urethroplasty is required (for instance when ventral chordee release with urethral lengthening is preferred to a dorsal Nesbit procedure, or when replacing a hairy or BXO diseased urethra), then a 2-stage procedure such as described by Bracka [20] is the best option. (fig. 6).
The advent of buccal mucosa as a urethral substitution material has revolutionised the management of these challenging cases. Unlike bladder mucosa, which is an obligatory wet mucosa that therefore has to be used as a 1-stage tube and kept away from the meatus, buccal mucosa is a robust material that that can be left exposed to the air for long periods. For this reason it can be used for 2-stage urethroplasty in much the same way as a full thickness skin graft. By allowing a period of 4-6 months between the operations, the graft has adequate opportunity to mature and complete any contraction that may take place.
With this in mind one usually places a slightly wider than required graft at the first stage. Any surplus width can always be discarded along with the lateral junctional scars at the second stage. Conversely, should there be a significant area of narrowing, there is then the opportunity to augment this site with a dorsal inlay patch graft at the time of the second stage. Because the graft width, the meatal margins and the proximal junctional area are already matured at the time of tubing, no maintenance in the form of self-dilatations will be necessary during the post-operative period. This is in contra-distinction to single stage buccal graft tubes, which have complication rates up to 50% and require a prolonged period of post-operative calibration to prevent the formation of junctional strictures. In most instances one can harvest sufficient mucosa from the mouth to replace the entire penile urethra without creating secondary donor site morbidity. Whilst the lower lip is a useful source of mucosa for augmentation patch grafting, the cheeks are the preferred donor site for full width substitution urethroplasty. This is particularly so in adults, wherein the mouth to penis size ratio is considerably less favourable than in children. Cheek donor sites should be closed directly to minimise post-operative discomfort. Taking into account the bacterial flora of the oral cavity, antibiotic prophylaxis should cover anaerobic organisms as well as usual urinary pathogens, hence our preference for co-amoxiclav.
Further mention should be made of BXO (lichen sclerosus) as this is one of the most important, yet often unrecognised causes of late hypospadias failures. Author (AB) has treated more than 100 cases of hypospadias complicated by the presence of histologically proven BXO [30]. It must be emphasised that when the BXO is still confined to the penile urethra, the only effective long-term solution is to substitute the entire diseased segment with buccal mucosa. In the case of neglected disease that has been allowed to spread proximally to involve the bulbar urethra, a combination of buccal and bladder mucosa will then be required.
Augmentation procedures, dilatations and endoscopic urethrotomies do not cure BXO. They provide only temporary relief, whilst allowing insidious progression of disease down the urethra. Substitution with genital skin leads to re-stricture usually within a couple of years. Non-genital skin, such as post-auricular Wolfe grafts, may remain healthy for much longer, and an early discharge policy can therefore induce false optimism. However, almost every reconstruction with non-genital skin will also have re-strictured within 10 years.

 

Conclusions

The authors present a very simple and reliable protocol for the correction of almost all primary and redo hypospadias, using only a very few logically related surgical procedures. It will be appreciated that in essence this protocol depends on the quality and development of the urethral plate, rather than the pre-operative location of the meatus.

1-stage repair is used when the urethral plate does not require transection, and its axial integrity can be maintained. Occasionally, when the plate is of adequate width and depth, it can be tubed directly using the 2nd stage of the 2-stage repair (alias the GAP procedure). When, as is usually the case, the urethral plate is not adequately developed and requires width/depth augmentation before it can be tubed, then that 2nd stage procedure is modified by the addition of a dorsal releasing incision +/- a graft (alias Snodgrass and “Snodgraft” procedures).

2-stage repair offers the most reliable and refined solution for those patients who require transection of the urethral plate and a full circumference substitution urethroplasty.

On the evidence available, this protocol combines excellent function and cosmesis with optimum reliability. Nevertheless, for reasons already stated, it would be complacent to assume that these gratifying results will be maintained into adult life. We therefore recommend that there is still a need for active follow-up through to genital maturity.

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