# Hypospadias

Authors: N. Djakovic; J. Nyarangi-Dix; A. Özturk; M. Hohenfellner
Journal: Advances in Urology
 (2008)

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## Abstract

Objective. The great possibility of variations in the clinical presentation of hypospadia, makes its therapy challenging. This has led to the development of a number of techniques for hypospadia repair. This article assesses past and present concepts and operative techniques with the aim of broadening our understanding of this malformation. Materials and Methods. The article not only reviews hypospadia in general with its development and clinical presentation as well as historical and current concepts in hypospadiologie on the basis of available literature, but it is also based on our own clinical experience in the repair of this malformation. Results and Conclusion. The fact that there are great variations in the presentation and extent of malformations existent makes every hypospadia individual and a proposal of a universal comprehensive algorithm for hypospadia repair difficult. The Snodgrass technique has found wide popularity for the repair of distal hypospadias. As far as proximal hypospadias are concerned, their repair is more challenging because it not only involves urethroplasty, but can also, in some cases, fulfil the dimensions of a complex genital reconstruction. Due to the development of modern operating materials and an improvement in current surgical techniques, there has been a significant decrease in the complication rates. Nonetheless, there still is room and, therefore, need for further improvement in this field.


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## Body

## 1. Introduction

### 1.1. Definition, Incidence and Classification

With an incidence of 1:300, hypospadia is one
of the most common genital anomalies in male newborns [1].
Hypospadia is defined as an anomaly (hypo- or dysplasia) involving the ventral
aspect of the penis [2]. These malformations mainly comprise of an
abnormal ventral opening of the urethral meatus, an abnormal ventral curvature of
the penis (chordee) and/or an abnormal distribution of the foreskin. The extent
of the malformation varies.Such ectopic urethral openings (meatus) can be located
at the tip of the glans penis (hypospadia sine hypospadia), glanular, coronal, subcoronal,
along the penile shaft, penoscrotal, scrotal, or perineal. The form and extent
of malformation of the urethral opening varies as well and is in some cases widely
gaping and resembling the mouth of a fish. A stenosis is rather rare.Generally, severe forms of hypospadia are
typically accompanied by an abnormal ventral curvature of the penis (chordee).
This is due to the difference in length between the ventral and the dorsal side
of the penis (corporocavernosal dysproportion). Proximal hypospadias frequently
have a penoscrotal transposition and/or bifid scrotum.Further abnormalities in hypospadia concern the
prepuce. Typically, there is a dorsal hump with excessive skin on the dorsal and
a scarcity of foreskin on the ventral aspect of the penis. In most cases, the
frenulum is entirely missing. In the rare cases when the prepuce is normally
developed, it must be preserved and a circumcision avoided [3].


### 1.2. Background

The hypospadic penis is often anatomically similar
to the normal penis, at least as far as the dorsal aspect is concerned.
However, the ventral aspect is pathological: the development of the prepuce
incomplete, the formation of the urethral plate into a urethra defective and the
corpus spongiosum deficient. Histologically, the urethral plate consists of
well-vascularised tissue with large endothelial sinuses lined around an abortive
urethral spongiosum. Fibrosis and cicatrisation are rarely available [4]. These characteristics make the urethral plate ideal
for urethroplasty [5].The development of the urethral plate is genetically
influenced by cell differentiation, hormonal and enzymatic activity, as well as tissue
transformation. Before the 7th week of gestation, the structure of
the genital is indifferent [2, 6]. Afterwards, the tissue differentiation, including
the elongation of the phallus, the formation of the penile urethra, and the
development of the prepuce [7] are influenced by the presence or absence of androgens
and the signals of the SRY-gene. More recent studies support the theory of endodermal
differentiation. According to this theory, the entire urethra stems from the
urogenital sinus [8]. The continual development of the urethral plate
into the genital tubercle is followed by the ventral fusion of the urethral
folds [9]. The development of the prepuce not only occurs
simultaneous to the fusion of the urethral plate, this development in fact
depends on it. In cases where the fusion of the urethral plate is altered, the
prepuce on the ventral aspect of the penis remains underdeveloped.Interferences in the androgen metabolism, for example, 5α-Reductase
deficit, defects of the androgen receptor, or gene defects are possible aetiological
factors for hypospadia, that are only found in <5% of the patients [10, 11]. Hypospadia is also found as a part of different
syndromes.The incidence of hypospadia is increasing
worldwide. A possible explanation for this trend could be the increasing
environmental pollution. In this context, it is known that human beings
increasingly ingest substances with estrogen, for example, as found in certain
insecticides, natural herbs, and so forth. Animal models demonstrated that estrogens lead
to an alteration or even complete interruption of the development of the penis
[12]. The aetiology of the majority of hypospadias though
remains unknown.


## 1.1. Definition, Incidence and Classification

With an incidence of 1:300, hypospadia is one
of the most common genital anomalies in male newborns [1].
Hypospadia is defined as an anomaly (hypo- or dysplasia) involving the ventral
aspect of the penis [2]. These malformations mainly comprise of an
abnormal ventral opening of the urethral meatus, an abnormal ventral curvature of
the penis (chordee) and/or an abnormal distribution of the foreskin. The extent
of the malformation varies.Such ectopic urethral openings (meatus) can be located
at the tip of the glans penis (hypospadia sine hypospadia), glanular, coronal, subcoronal,
along the penile shaft, penoscrotal, scrotal, or perineal. The form and extent
of malformation of the urethral opening varies as well and is in some cases widely
gaping and resembling the mouth of a fish. A stenosis is rather rare.Generally, severe forms of hypospadia are
typically accompanied by an abnormal ventral curvature of the penis (chordee).
This is due to the difference in length between the ventral and the dorsal side
of the penis (corporocavernosal dysproportion). Proximal hypospadias frequently
have a penoscrotal transposition and/or bifid scrotum.Further abnormalities in hypospadia concern the
prepuce. Typically, there is a dorsal hump with excessive skin on the dorsal and
a scarcity of foreskin on the ventral aspect of the penis. In most cases, the
frenulum is entirely missing. In the rare cases when the prepuce is normally
developed, it must be preserved and a circumcision avoided [3].


## 1.2. Background

The hypospadic penis is often anatomically similar
to the normal penis, at least as far as the dorsal aspect is concerned.
However, the ventral aspect is pathological: the development of the prepuce
incomplete, the formation of the urethral plate into a urethra defective and the
corpus spongiosum deficient. Histologically, the urethral plate consists of
well-vascularised tissue with large endothelial sinuses lined around an abortive
urethral spongiosum. Fibrosis and cicatrisation are rarely available [4]. These characteristics make the urethral plate ideal
for urethroplasty [5].The development of the urethral plate is genetically
influenced by cell differentiation, hormonal and enzymatic activity, as well as tissue
transformation. Before the 7th week of gestation, the structure of
the genital is indifferent [2, 6]. Afterwards, the tissue differentiation, including
the elongation of the phallus, the formation of the penile urethra, and the
development of the prepuce [7] are influenced by the presence or absence of androgens
and the signals of the SRY-gene. More recent studies support the theory of endodermal
differentiation. According to this theory, the entire urethra stems from the
urogenital sinus [8]. The continual development of the urethral plate
into the genital tubercle is followed by the ventral fusion of the urethral
folds [9]. The development of the prepuce not only occurs
simultaneous to the fusion of the urethral plate, this development in fact
depends on it. In cases where the fusion of the urethral plate is altered, the
prepuce on the ventral aspect of the penis remains underdeveloped.Interferences in the androgen metabolism, for example, 5α-Reductase
deficit, defects of the androgen receptor, or gene defects are possible aetiological
factors for hypospadia, that are only found in <5% of the patients [10, 11]. Hypospadia is also found as a part of different
syndromes.The incidence of hypospadia is increasing
worldwide. A possible explanation for this trend could be the increasing
environmental pollution. In this context, it is known that human beings
increasingly ingest substances with estrogen, for example, as found in certain
insecticides, natural herbs, and so forth. Animal models demonstrated that estrogens lead
to an alteration or even complete interruption of the development of the penis
[12]. The aetiology of the majority of hypospadias though
remains unknown.


## 2. Treatment

Surgical reconstruction is the only possible
therapeutic option for hypospadia [2]. The primary objectives of the reconstruction are to
create a vertically slit orthotopic meatus, straighten the penis in case of
curvature and establish good cosmetic results that include a conically shaped
glans. Other important aspects for the reconstruction are to avoid shortening
the penis and optimal skin coverage that excludes the use scrotal skin for
coverage of the penis.The optimal age for correction of hypospadia is
between the 6th and the 24th month. Thanks to the
possibility of topical application of dihydrotestosterone, it is possible to optimise
the size of the penis at this early age of operation [13]. In the majority of cases, the operation can be done
in one step. A two-step approach is rarely necessary, for example, in case of
insufficiency of the urethral plate or hypoplastic skin as often found in Re-Do
Hypospadias [14].Successful hypospadia surgery incorporates the
following steps: straightening of the penis (orthoplasty), reconstruction of
the urethra (urethroplasty), the meatus (meatoplasty), the glans
(glanuloplasty) and the skin of the penis as well as that of the scrotum
whenever necessary.


### 2.1. History

The fact that there are over 250 methods of
surgical correction of hypospadias described in the literature indicates that
the “hypospadiologists” are still in search of the ideal technique. The
statement: “There is nothing new in surgery not previously described” [15] is especially true as far as hypospadia repair is
concerned, because many so believed new techniques were, as a matter of fact,
originally described in historical documents and books.In the 19th century, Dieffenbach [16] tried to reconstruct a neourethra
through secondary epithelialisation by perforating the glans with a canula and
therefore establishing a connection to the hypospadic urethra. Theofil Anger first
used tubularised local flaps in the 19th century for hypospadia
repair [17]. In 1875, Wood introduced the
“meatal-based-flap-technique” that is the basic idea behind the Mathieu
technique [18]. The idea of reconstructing the neourethra out of a vascularised
island flap was also first described in the 19th century. In
connection with this, Van Hook described the reconstruction of the neourethra
with a dorsal preputial flap. The idea of using a free flap for urethroplasty
is also not new. Towards the end of the 19th century, Nove-Josserand
used skin grafts for the urethral reconstruction [19].The above-mentioned techniques were further
pursued and advanced in the 20th century. Ombrédanne created the
neourethra out of a round local submeatal flap and covered it with a dorsal
preputial flap [19]. Similar strategies were followed by Mathieu and
Brown. Horton and Devine introduced the so called “Flip-Flap technique” for the
correction of distal hypospadias that is favoured by certain surgeons up to
date [20]. At the same time, techniques that preferentially
use vascularised island flaps were also further pursued. The best known of
these is undoubtedly the urethroplasty using a transverse preputial island flap
as popularised by Duckett in 1980 [21]. Although several trials were performed in the 20th century with free flaps, buccal mucosa is the only regularly used graft at the
moment [22].The mobilisation and elongation of the urethra
is an interesting concept, which can in some cases be used to avoid
urethroplasty. Duckett's principle, which is also known as “MAGPI,” is based on
this concept [23]. This idea too is not new and was first described by
Beck in 1889 [24].Even though under different conditions, the
same concepts are still applied up to date. The surgical results have been further
improved by the use of modern sutures, loupe magnification, modern dressing
material, better foley catheters, and better methods for the diagnostic and
correction of penis curvature through artificial or medically induced
erections.


### 2.2. Urethroplasty

The selection of the surgical technique for the
reconstruction of the neourethra should not only be influenced by the position
of the meatus but must in fact take the entire complex of anomalies—that is, the
quality of the urethral plate as well as that of the penile skin, the form of
the glans, the length of the urethra, and the grade of corporocavernosal
dysproportion—into consideration.The major techniques of urethroplasty are
described in detail under the subtitles “proximal hypospadias” and “distal
hypospadias.”


### 2.3. Orthoplasty and Penile Skin Coverage

The penile curvature results from the
dysplasia/hypoplasia on the ventral aspect of the penis. Mild curvatures can
already be corrected by complete mobilisation of the penile skin. This way, the
so-called, “skin chordee” can be released. If the curvature is still existent
after such mobilisation, other methods must be applied [25].The presence of altered fibrotic tissue around
the urethral plate and on the ventral aspect of the penis is seldom. This is,
therefore, a rather rare reason for penile curvatures. It makes it also easy to
understand that a chordectomy alone rarely leads to a straightening of the
penis [2]. About 5% of the patients have a so-called
corporocavernosal disproportion, which is an effect of the disparity in the
development of the tunica albuginea on the ventral and dorsal aspects of the
penis [25, 26].Depending on the extent of the penile
curvature, the reconstruction can either be performed per dorsal corporoplasty
or with the use of a ventral patch. In the recent past, a number of authors
seem to increasingly favour the midline dorsal plication [2]. This technique is based on studies on fetal
phallus, which detected that there are no nerves running in the neurovascular
bundles in the midline [26]. Mild and moderate curvatures can be corrected with
this technique. We correct curvatures up to 40° using Yachia's technique [27]. To avoid extreme shortening of the penis during
correction of more severe penile curvatures, a ventral patch, in most cases out
of preputial skin, can be used.The reconstruction of the penile skin is
particularly challenging after degloving, “excavation” of the penis, and
urethroplasty. In such cases, it is important to pay attention not to embed the
penis in the scrotum or the mons pubis. In cases of simultaneous penoscrotal
transposition, the anomaly can also be corrected within the same session. This
is done with scrotal rotational flaps that are only mobilised up to the
subcutaneous layer in order not to compromise the vascularisation of the island
flaps and the penile skin [14].The straightening of the penis as well as an
optimal plastic reconstruction of the scrotum and penile skin demands great
expertise.


### 2.4. Distal Hypospadias

The majority of patients with this type of
hypospadia can urinate with a straight urine stream and have not pronounced
penile curvatures. Nonetheless, most parents wish for a “normal penis” for
their child. Therefore, the surgical reconstruction of distal hypospadias must
meet these cosmetic requirements [2]. The psychosocial aspect is another important factor
to consider while making the decision on performing the operative
reconstruction in this group of patients.As of today, the meatal advancement
urethroplasty (MAGPI), glans approximation procedure (GAP), Mathieu's procedure
and the tubularised incised plate urethroplasty (Snodgrass technique) are among
the most established and reliable methods [2].With the use of the urethral plate for
urethroplasty, the complication rate has been clearly reduced. At the
beginning, primary tubularisation, also known as the Thiersch-Duplay, was performed
in patients with wide urethral plates and deep fossa navicularis [28]. In cases where the urethral plate is narrow, the
Mathieu or MAGPI technique or variants thereof are applied. With these methods,
a submeatal-based flap is augmented on the narrow urethral plate and the meatus
repositioned on the glans [2].Lately, the concept of incision and
tubularisation of the urethral plate with consecutive secondary healing, as
popularised by Snodgrass et al. [29], has revolutionised hypospadia surgery [5, 29]. Its low complication rates, excellent cosmetic
results and the simple surgical technique have made it very popular among
hypospadia surgeons [30]. The initial concerns and, subsequently, reports about
increased stenosis have become quite seldom [31, 32]. As long as there is no penile curvature, this
technique is the method of choice for distal hypospadias [32]. This method is increasingly applied for the repair
of penile hypospadias as well [29].Nonetheless, there are still complications mostly
fistulas reported in [32]. In order to prevent fistulas, particularly healthy tissue
from different areas is used to cover the neourethra using different
techniques. Retik described the use of asymmetrical flaps from the dorsal
penile skin and the prepuce [33]. Other authors use distal extensions of the parting
corpus spongiosum to cover the neourethra [34]. Sozubir and Snodgrass used a dorsal dartos flap
that was transposed to the ventral aspect of the penis over a buttonhole
technique.We, on our part, favour the longitudinal dorsal
dartos flap. Mobilising the penile skin involves complete
preservation of the dorsal hump. This skin is stretched by two stay sutures,
and then incised proximal to the subcoronar region (see Figure1). The preparation and deepithelialisation of the
dartos flap begins proximal to the dorsal hump in an area where the
subcutaneous tissue is not pathologically altered. This way, the preparation of
the dartos flap is eased and a complete preservation of a well-vascularised
dartos flap is possible (see Figure 1).Preparation of the dartos flap.
(a)(b)The urethral plate is
mobilised in the layer of Buck's fascia and the tip of the glans incised at the
fossa navicularis. In order to enable a tension-free suturing-up of the glans,
the incision must be made all the way to the cavernous bodies. After making a
midline incision into the urethral plate, it is tubularised with a continuous 7/0
Vicryl suture around a 6 Fr catheter. The dartos flap is then transpositioned
to the ventral aspect of the penis with the buttonhole technique and sutured
into the incised glans (see Figure2).
This way the neourethra is well covered by this dartos flap.Figure 2
Incised and tubularised urethral plate with the ventrally transpositioned dartos flap.The glanuloplasty is done with two-layer
sutures of Vicryl 7/0. In order to avoid stenosis, it is important to create a
wide-enough meatus and evert it afterwards [32].


### 2.5. Proximal Hypospadias

Usually, the intensity of the ventral dys- and
hypoplasia increases with increasing grade of hypospadia. That means that the
skin on the ventral aspect of the penis and the usability of the urethral plate
decreases with an increase in grade of dysplasia. At the same time the penile
curvature increases, which makes it sometimes necessary to transect the
urethral plate. This special anatomic constitution demands the selection of a
surgical technique that is complex and challenging [25].In such forms of hypospadia, the penis must be
first straightened, the urethral plate mobilised up to healthy corpus
spongiosum and then the urethroplasty performed with additional tissue. Principally,
pedicled or free flaps are used to reconstruct the neourethra in onlay
technique. The key to success, in this case, is the preservation of the
urethral plate that builds the ventral portion of the neourethra. Most surgeons
reconstruct the dorsal portion out of a pedicled inner preputial skin graft [2, 35, 36]. With the integration of the urethral plate,
complications like proximal stenosis can be avoided. Furthermore, the fistula rate
can be decreased down to 5–10% by using well-vascularised pedicled island
grafts [36, 37]. This method has proved its worth in the long run [37–40].We generally prefer the use of the longitudinal
preputial/penile island flap from the preputial and/or the dorsal penile skin.
During preparation of the flap, two lateral devascularised skin portions are
developed with the vascularisation in favour of a centrally situated island
flap (Figure3). The devascularised skin is later trimmed off during
the reconstruction of the penile skin. The length, width, and shape of this
dorsal island flap are formed according to the morphology and quality of the
urethral plate. The island flap is transposed ventrally with the buttonhole
technique (Figures 3 and 4). Its
pedicle contains, in respect to the flap, axially
aligned vascularisation.Ventral transposition of the
longitudinal dorsal dartos flap with the buttonhole technique. Star shows the glans.
(a)(b)(c)Figure 4
Dorsal perspective of the longitudinal island flap. The graft is
right in the centre of the vascular pedicle. The buttonhole is already made.The reconstruction of
the neourethra is done in “onlay technique.” First, the island flap is distally
fixed to the hypospadic meatus with interrupted sutures (Vicryl 7/0). Both of
the sides of the anastomosis of the onlay are sutured with running suture. Both
suture lines of this anastomosis are completely covered by the vascular pedicle
of the dorsal island flap. The advantage of this flap over the Duckett-flap is that
the longitudinal dorsal island flap lies right in the middle of a wide and well-vascularised pedicle (Figure4).
It is thus an island flap that lies in line with its vascularisation [16, 17]. On the other hand all suture lines are fully
covered up by well-vascularised tissue. This way badly perfused borders and
corners that are predispose to fistulation are avoided.Generally, the urethral plate can be preserved
while straightening the penis. In certain cases though, it must be lifted and incised
(Figure5). In yet other cases, the urethral plate is missing
completely. In such patients, a tubularised urethroplasty is performed by using
an island flap formed into a role to bridge the missing section of the urethral
plate. Due to its increased complication rate, this tubularised urethroplasty
has been abandoned by most surgeons. Such complications include segmental
strictures and diverticula that occur in up to 69% of the cases [41].Figure 5
After complete mobilisation of the urethra and artificial erection of the penis, the ventral
curvature with a short urethral plate becomes evident.An alternative to tubularised urethroplasty for
complex and secondary hypospadias are two-step approaches, the most popular of
them being the two-step technique of repair according to Bracka [42, 43]. In the 1st step, the penis is
straightened and the cicatrisation of the urethral plate eliminated. A mucosal
graft out of the cheek or lower lip is harvested and placed on the prepared
bed. The tips of the glans are also reconstructed and lined with the mucosal
graft. In the 2nd step, approximately. 6 months later, the mucosal grafts are
mobilised, trimmed around the glans and tubularised to a neourethra. Bracka has
reported good results in complex hypospadias with this method. Nonetheless, a
two-step technique has a relevant disadvantage, namely that of the second
operation with its additional complications as well as the negative
psychosocial effects on the patient and his family [44].In order to be able to perform a one-step
procedure, a number of studies have been presented in the recent past
describing the use of a combination of mucosal grafts and local flaps. In such
cases, the defect that results from incision of the urethral plate is bridged
over using a mucosal inlay graft and the neourethra is reconstructed out of an
island flap in onlay technique and all that in a single procedure [44]. This way, the advantages of a one-step procedure as
well as those of the onlay technique are both exploited.We on our part favour the longitudinal
preputial and penile skin island flap. First the penile skin is mobilised, then
the urethral plate is incised vertically beginning at the hypospadic meatus all
the way to the glans thereby building two glanular wings proximally. This
mobilised urethral plate then lies as a groove between both glanular wings. In
order to avoid bleeding out of dysplastic lateral branches of the corpus
spongiosum, the preparation of the distal section of the urethral plate is done
along Buck's fascia.The decision of
whether or not to horizontally incise the urethral plate is made depending on
the intraoperative findings after artificial erection (Figure5). We do the incision of the urethral plate proximal
to the balanopenile furrow. This way, the proximal stump of the urethral plate
is retracted and it, therefore, interrupted/missing along the mid section of the
penis (Figure 6). In the next step we straighten the penis and then
harvest the buccal mucosal graft. This graft is then perforated to enable
drainage of haematoma between the cavernous bodies and the placed graft. We
then place the buccal mucosal inlay graft on the cavernous bodies and fix it between
the retracted proximal and the distal ends of the urethral plate (Figure 7). In order to enable a large surface of adhesion
between the graft and the tunica albuginea, the graft is quilted on to its bed
with Vicryl rapid 7/0.Figure 6
After horizontal incision of the
urethral plate the penis is still ventrally curved and a large defect in the
distal part of the urethral plate is revealed.Straightening of the penis (a).
The mucosal inlay graft is fixed on the cavernous bodies (b). The longitudinal
island flap is ready for the onlay anastomosis (b).
(a)(b)In the same session,
a longitudinal preputial/penile island flap won out of the preputial and dorsal
penile skin is used for the reconstruction of the neourethra in onlay technique
(Figure7, [35]). Rotational and additionally island skin flaps are
used in combination for coverage of the penis. A single-step procedure can be
performed in 75% of the children with penoscrotal transpositions [14].


## 2.1. History

The fact that there are over 250 methods of
surgical correction of hypospadias described in the literature indicates that
the “hypospadiologists” are still in search of the ideal technique. The
statement: “There is nothing new in surgery not previously described” [15] is especially true as far as hypospadia repair is
concerned, because many so believed new techniques were, as a matter of fact,
originally described in historical documents and books.In the 19th century, Dieffenbach [16] tried to reconstruct a neourethra
through secondary epithelialisation by perforating the glans with a canula and
therefore establishing a connection to the hypospadic urethra. Theofil Anger first
used tubularised local flaps in the 19th century for hypospadia
repair [17]. In 1875, Wood introduced the
“meatal-based-flap-technique” that is the basic idea behind the Mathieu
technique [18]. The idea of reconstructing the neourethra out of a vascularised
island flap was also first described in the 19th century. In
connection with this, Van Hook described the reconstruction of the neourethra
with a dorsal preputial flap. The idea of using a free flap for urethroplasty
is also not new. Towards the end of the 19th century, Nove-Josserand
used skin grafts for the urethral reconstruction [19].The above-mentioned techniques were further
pursued and advanced in the 20th century. Ombrédanne created the
neourethra out of a round local submeatal flap and covered it with a dorsal
preputial flap [19]. Similar strategies were followed by Mathieu and
Brown. Horton and Devine introduced the so called “Flip-Flap technique” for the
correction of distal hypospadias that is favoured by certain surgeons up to
date [20]. At the same time, techniques that preferentially
use vascularised island flaps were also further pursued. The best known of
these is undoubtedly the urethroplasty using a transverse preputial island flap
as popularised by Duckett in 1980 [21]. Although several trials were performed in the 20th century with free flaps, buccal mucosa is the only regularly used graft at the
moment [22].The mobilisation and elongation of the urethra
is an interesting concept, which can in some cases be used to avoid
urethroplasty. Duckett's principle, which is also known as “MAGPI,” is based on
this concept [23]. This idea too is not new and was first described by
Beck in 1889 [24].Even though under different conditions, the
same concepts are still applied up to date. The surgical results have been further
improved by the use of modern sutures, loupe magnification, modern dressing
material, better foley catheters, and better methods for the diagnostic and
correction of penis curvature through artificial or medically induced
erections.


## 2.2. Urethroplasty

The selection of the surgical technique for the
reconstruction of the neourethra should not only be influenced by the position
of the meatus but must in fact take the entire complex of anomalies—that is, the
quality of the urethral plate as well as that of the penile skin, the form of
the glans, the length of the urethra, and the grade of corporocavernosal
dysproportion—into consideration.The major techniques of urethroplasty are
described in detail under the subtitles “proximal hypospadias” and “distal
hypospadias.”


## 2.3. Orthoplasty and Penile Skin Coverage

The penile curvature results from the
dysplasia/hypoplasia on the ventral aspect of the penis. Mild curvatures can
already be corrected by complete mobilisation of the penile skin. This way, the
so-called, “skin chordee” can be released. If the curvature is still existent
after such mobilisation, other methods must be applied [25].The presence of altered fibrotic tissue around
the urethral plate and on the ventral aspect of the penis is seldom. This is,
therefore, a rather rare reason for penile curvatures. It makes it also easy to
understand that a chordectomy alone rarely leads to a straightening of the
penis [2]. About 5% of the patients have a so-called
corporocavernosal disproportion, which is an effect of the disparity in the
development of the tunica albuginea on the ventral and dorsal aspects of the
penis [25, 26].Depending on the extent of the penile
curvature, the reconstruction can either be performed per dorsal corporoplasty
or with the use of a ventral patch. In the recent past, a number of authors
seem to increasingly favour the midline dorsal plication [2]. This technique is based on studies on fetal
phallus, which detected that there are no nerves running in the neurovascular
bundles in the midline [26]. Mild and moderate curvatures can be corrected with
this technique. We correct curvatures up to 40° using Yachia's technique [27]. To avoid extreme shortening of the penis during
correction of more severe penile curvatures, a ventral patch, in most cases out
of preputial skin, can be used.The reconstruction of the penile skin is
particularly challenging after degloving, “excavation” of the penis, and
urethroplasty. In such cases, it is important to pay attention not to embed the
penis in the scrotum or the mons pubis. In cases of simultaneous penoscrotal
transposition, the anomaly can also be corrected within the same session. This
is done with scrotal rotational flaps that are only mobilised up to the
subcutaneous layer in order not to compromise the vascularisation of the island
flaps and the penile skin [14].The straightening of the penis as well as an
optimal plastic reconstruction of the scrotum and penile skin demands great
expertise.


## 2.4. Distal Hypospadias

The majority of patients with this type of
hypospadia can urinate with a straight urine stream and have not pronounced
penile curvatures. Nonetheless, most parents wish for a “normal penis” for
their child. Therefore, the surgical reconstruction of distal hypospadias must
meet these cosmetic requirements [2]. The psychosocial aspect is another important factor
to consider while making the decision on performing the operative
reconstruction in this group of patients.As of today, the meatal advancement
urethroplasty (MAGPI), glans approximation procedure (GAP), Mathieu's procedure
and the tubularised incised plate urethroplasty (Snodgrass technique) are among
the most established and reliable methods [2].With the use of the urethral plate for
urethroplasty, the complication rate has been clearly reduced. At the
beginning, primary tubularisation, also known as the Thiersch-Duplay, was performed
in patients with wide urethral plates and deep fossa navicularis [28]. In cases where the urethral plate is narrow, the
Mathieu or MAGPI technique or variants thereof are applied. With these methods,
a submeatal-based flap is augmented on the narrow urethral plate and the meatus
repositioned on the glans [2].Lately, the concept of incision and
tubularisation of the urethral plate with consecutive secondary healing, as
popularised by Snodgrass et al. [29], has revolutionised hypospadia surgery [5, 29]. Its low complication rates, excellent cosmetic
results and the simple surgical technique have made it very popular among
hypospadia surgeons [30]. The initial concerns and, subsequently, reports about
increased stenosis have become quite seldom [31, 32]. As long as there is no penile curvature, this
technique is the method of choice for distal hypospadias [32]. This method is increasingly applied for the repair
of penile hypospadias as well [29].Nonetheless, there are still complications mostly
fistulas reported in [32]. In order to prevent fistulas, particularly healthy tissue
from different areas is used to cover the neourethra using different
techniques. Retik described the use of asymmetrical flaps from the dorsal
penile skin and the prepuce [33]. Other authors use distal extensions of the parting
corpus spongiosum to cover the neourethra [34]. Sozubir and Snodgrass used a dorsal dartos flap
that was transposed to the ventral aspect of the penis over a buttonhole
technique.We, on our part, favour the longitudinal dorsal
dartos flap. Mobilising the penile skin involves complete
preservation of the dorsal hump. This skin is stretched by two stay sutures,
and then incised proximal to the subcoronar region (see Figure1). The preparation and deepithelialisation of the
dartos flap begins proximal to the dorsal hump in an area where the
subcutaneous tissue is not pathologically altered. This way, the preparation of
the dartos flap is eased and a complete preservation of a well-vascularised
dartos flap is possible (see Figure 1).Preparation of the dartos flap.
(a)(b)The urethral plate is
mobilised in the layer of Buck's fascia and the tip of the glans incised at the
fossa navicularis. In order to enable a tension-free suturing-up of the glans,
the incision must be made all the way to the cavernous bodies. After making a
midline incision into the urethral plate, it is tubularised with a continuous 7/0
Vicryl suture around a 6 Fr catheter. The dartos flap is then transpositioned
to the ventral aspect of the penis with the buttonhole technique and sutured
into the incised glans (see Figure2).
This way the neourethra is well covered by this dartos flap.Figure 2
Incised and tubularised urethral plate with the ventrally transpositioned dartos flap.The glanuloplasty is done with two-layer
sutures of Vicryl 7/0. In order to avoid stenosis, it is important to create a
wide-enough meatus and evert it afterwards [32].


## 2.5. Proximal Hypospadias

Usually, the intensity of the ventral dys- and
hypoplasia increases with increasing grade of hypospadia. That means that the
skin on the ventral aspect of the penis and the usability of the urethral plate
decreases with an increase in grade of dysplasia. At the same time the penile
curvature increases, which makes it sometimes necessary to transect the
urethral plate. This special anatomic constitution demands the selection of a
surgical technique that is complex and challenging [25].In such forms of hypospadia, the penis must be
first straightened, the urethral plate mobilised up to healthy corpus
spongiosum and then the urethroplasty performed with additional tissue. Principally,
pedicled or free flaps are used to reconstruct the neourethra in onlay
technique. The key to success, in this case, is the preservation of the
urethral plate that builds the ventral portion of the neourethra. Most surgeons
reconstruct the dorsal portion out of a pedicled inner preputial skin graft [2, 35, 36]. With the integration of the urethral plate,
complications like proximal stenosis can be avoided. Furthermore, the fistula rate
can be decreased down to 5–10% by using well-vascularised pedicled island
grafts [36, 37]. This method has proved its worth in the long run [37–40].We generally prefer the use of the longitudinal
preputial/penile island flap from the preputial and/or the dorsal penile skin.
During preparation of the flap, two lateral devascularised skin portions are
developed with the vascularisation in favour of a centrally situated island
flap (Figure3). The devascularised skin is later trimmed off during
the reconstruction of the penile skin. The length, width, and shape of this
dorsal island flap are formed according to the morphology and quality of the
urethral plate. The island flap is transposed ventrally with the buttonhole
technique (Figures 3 and 4). Its
pedicle contains, in respect to the flap, axially
aligned vascularisation.Ventral transposition of the
longitudinal dorsal dartos flap with the buttonhole technique. Star shows the glans.
(a)(b)(c)Figure 4
Dorsal perspective of the longitudinal island flap. The graft is
right in the centre of the vascular pedicle. The buttonhole is already made.The reconstruction of
the neourethra is done in “onlay technique.” First, the island flap is distally
fixed to the hypospadic meatus with interrupted sutures (Vicryl 7/0). Both of
the sides of the anastomosis of the onlay are sutured with running suture. Both
suture lines of this anastomosis are completely covered by the vascular pedicle
of the dorsal island flap. The advantage of this flap over the Duckett-flap is that
the longitudinal dorsal island flap lies right in the middle of a wide and well-vascularised pedicle (Figure4).
It is thus an island flap that lies in line with its vascularisation [16, 17]. On the other hand all suture lines are fully
covered up by well-vascularised tissue. This way badly perfused borders and
corners that are predispose to fistulation are avoided.Generally, the urethral plate can be preserved
while straightening the penis. In certain cases though, it must be lifted and incised
(Figure5). In yet other cases, the urethral plate is missing
completely. In such patients, a tubularised urethroplasty is performed by using
an island flap formed into a role to bridge the missing section of the urethral
plate. Due to its increased complication rate, this tubularised urethroplasty
has been abandoned by most surgeons. Such complications include segmental
strictures and diverticula that occur in up to 69% of the cases [41].Figure 5
After complete mobilisation of the urethra and artificial erection of the penis, the ventral
curvature with a short urethral plate becomes evident.An alternative to tubularised urethroplasty for
complex and secondary hypospadias are two-step approaches, the most popular of
them being the two-step technique of repair according to Bracka [42, 43]. In the 1st step, the penis is
straightened and the cicatrisation of the urethral plate eliminated. A mucosal
graft out of the cheek or lower lip is harvested and placed on the prepared
bed. The tips of the glans are also reconstructed and lined with the mucosal
graft. In the 2nd step, approximately. 6 months later, the mucosal grafts are
mobilised, trimmed around the glans and tubularised to a neourethra. Bracka has
reported good results in complex hypospadias with this method. Nonetheless, a
two-step technique has a relevant disadvantage, namely that of the second
operation with its additional complications as well as the negative
psychosocial effects on the patient and his family [44].In order to be able to perform a one-step
procedure, a number of studies have been presented in the recent past
describing the use of a combination of mucosal grafts and local flaps. In such
cases, the defect that results from incision of the urethral plate is bridged
over using a mucosal inlay graft and the neourethra is reconstructed out of an
island flap in onlay technique and all that in a single procedure [44]. This way, the advantages of a one-step procedure as
well as those of the onlay technique are both exploited.We on our part favour the longitudinal
preputial and penile skin island flap. First the penile skin is mobilised, then
the urethral plate is incised vertically beginning at the hypospadic meatus all
the way to the glans thereby building two glanular wings proximally. This
mobilised urethral plate then lies as a groove between both glanular wings. In
order to avoid bleeding out of dysplastic lateral branches of the corpus
spongiosum, the preparation of the distal section of the urethral plate is done
along Buck's fascia.The decision of
whether or not to horizontally incise the urethral plate is made depending on
the intraoperative findings after artificial erection (Figure5). We do the incision of the urethral plate proximal
to the balanopenile furrow. This way, the proximal stump of the urethral plate
is retracted and it, therefore, interrupted/missing along the mid section of the
penis (Figure 6). In the next step we straighten the penis and then
harvest the buccal mucosal graft. This graft is then perforated to enable
drainage of haematoma between the cavernous bodies and the placed graft. We
then place the buccal mucosal inlay graft on the cavernous bodies and fix it between
the retracted proximal and the distal ends of the urethral plate (Figure 7). In order to enable a large surface of adhesion
between the graft and the tunica albuginea, the graft is quilted on to its bed
with Vicryl rapid 7/0.Figure 6
After horizontal incision of the
urethral plate the penis is still ventrally curved and a large defect in the
distal part of the urethral plate is revealed.Straightening of the penis (a).
The mucosal inlay graft is fixed on the cavernous bodies (b). The longitudinal
island flap is ready for the onlay anastomosis (b).
(a)(b)In the same session,
a longitudinal preputial/penile island flap won out of the preputial and dorsal
penile skin is used for the reconstruction of the neourethra in onlay technique
(Figure7, [35]). Rotational and additionally island skin flaps are
used in combination for coverage of the penis. A single-step procedure can be
performed in 75% of the children with penoscrotal transpositions [14].


## 3. Conclusion

Hypospadia surgery is challenging. The fact
that there are wide variations in the presentation and extent of malformations as
well as tissue characteristics existent makes every hypospadia individual and a
proposal of a universal comprehensive algorithm for hypospadia repair difficult.
The Snodgrass technique has found wide popularity for the repair of distal
hypospadias. As far as proximal hypospadias are concerned, their repair is
complex and could in fact be seen as a form of genital reconstruction. This
repair not only involves urethroplasty, but also has its goal in achieving good
cosmetic results with a straight normal-proportioned penis and an orthotopic
meatus in addition to the functional urethra. Even though the complication
rates have decreased, thanks to modern operating materials and an improvement
of current surgical techniques, there still is room and therefore need for
further improvement in this field.



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*Source: 650135-2008-10-30.xml*