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Hypospadias
Hypospadias is a birth defect found in boys in which the urinary
tract opening is not at the tip of the penis. Bending of the penis
on erection may be associated with this and is known as chordee. Hypospadias
occurs in about 8 of 1000 male births. There is some family risk of
hypospadias. When we see a boy with hypospadias there is a 20% chance
of finding it in another family member.
There are different degrees of hypospadias -- some minor and others
more severe. We name the types of hypospadias according to their anatomic
location, but one must always determine whether or not there is associated
chordee.
Reasons For Repair:
Surgical correction of hypospadias involves straightening of any
chordee and then extension of the urinary tube (urethra) out to the
tip of the penis (glans).
The ability to stand and urinate is important for boys. When the
urethra opens before it reaches the glans a boy may be unable to stand
and urinate with a direct stream. The youngster who has to sit down
to urinate on a toilet is at a painful social disadvantage.
A straight penis is necessary for satisfactory sexual function. Although
this may not seem to be an important matter in childhood, this is a
crucial concern later in life - early childhood is generally the best
time for correction.
Embryology:
The penis begins to form around the fifth fetal week. The urethral
folds start to unite over the urethral groove and by the fourteenth
week the process is complete. A short ingrowth from the tip of the
glans progresses inward to meet the urethral tube at the fossa navicularis.
Formation of a normal circumferential foreskin (prepuce) certifies
that the urethra has probably formed normally.
Surgical Correction Of Hypospadias And Chordee:
When the urethral opening is just slightly out of position and when
there is no chordee, surgical correction may not be necessary, although
in occasional patients there is a significant cosmetic reason for repair.
Mild to moderate grades of hypospadias with minimal chordee may be
corrected by simple outpatient procedures such as Meatal Advancement
and Glanduloplasty (MAGPI) or simple Flip-Flap procedures.
Moderate hypospadias with some chordee may require a more extensive
operation such as a Mustarde procedure which utilizes a tubularized
flap of penile shaft skin. Chordee is evaluated with an artificial
erection in which the erectile bodies are inflated with a saline solution.
To protect the newly constructed urethra (neourethra) the urine is
usually diverted with a stent (a silastic tube through the neourethra).
Patients may be sent home after surgery, but occasionally are hospitalized
for a day or two. Depending on the operation, a tube may be left in
the repair for 1 to 10 days.
More extensive hypospadias or chordee requires a bigger operation.
In the past, two and three-stage operations were used. In the first
stage the penis was straightened; this often made the hypospadias,
in terms of urethral location, worse. Six months to a year later construction
of the neourethra was initiated, using penile skin or free skin grafts.
Our current preference is to try to do most of this in one stage with
the Transverse Island Pedicle Tube Graft. This utilizes the inner portion
of the foreskin, retaining its own blood supply. The remaining outer
portion of foreskin resurfaces the front of the penis.
In some situations (such as perineal hypospadias, genital ambiguity,
or significant hypospadias with previous circumcision) more extensive
operations are necessary. The older multi-stage operations may be of
occasional use. In some situations we will make a neourethra out of
a graft of bladder lining or buccal mucosa.
Complications:
Bleeding is a risk of any operation. We keep this under control during
hypospadias surgery with epinephrine and cauterization. Postoperatively,
in the bigger repairs, we use a pressure dressing. Transfusion is almost
unheard of in hypospadias operations.
Infection is another concern. We use antibiotics to minimize this
risk.
Bladder spasms are usually due to indwelling catheters. It is ironic
that these safety measures account for most postoperative discomfort.
Medications help but do not eliminate spasms. Other catheter problems
including kinking, which causes the bladder to fill and then leak urine
around the stent or SP tube.
Fistula is another risk. This is a leak of urine from somewhere along
the neourethra. This risk is minimal in the simple repairs, but significant
in more extensive operations. Fistulas are usually easily fixed with
an outpatient surgical procedure, although this is done no sooner than
6 months after the original operation.
When extensive use is made of the foreskin for a neourethra (as in
the Transverse Island pedicle repairs) remaining foreskin may have
marginal blood supply and will slough. This will look like a scab or
eschar on the repaired penis and may result in fistula or skin tethering.
Corrective skin adjustment may be desirable. This is usually an outpatient
procedure and is also delayed at least six months. In some other patients
there may be cosmetic reasons for minor late skin adjustments.
Stricture or stenosis consists of narrowing where the neourethra
joins native urethra or at the level of the glans. These require dilation
(stretching) or internal urethrotomy (a cut through a cystoscopy).
Such measures may be repeatedly necessary as a stricture or stenosis
tries to reform.
Recurrent chordee is a difficult, and fortunately uncommon, problem.
Overall, the complications seen with the Transverse Island procedures
involve less surgery and trouble than the former two and three-stage
operations.
Chordee Without Hypospadias:
This is an unusual problem in which there is chordee (parents often
bring the child in to see us because "the penis is bent")
without apparent hypospadias. Skin tethering may be the main factor
in some patients, and this is usually readily fixed. In some boys the
distal urethra, even though intact, is paper thin (hypoplastic). Correction
of significant chordee in this setting may involve creation of hypospadias
to straighten the penis. The hypospadias must then be repaired in the
same or a stage operation. In other instances the bent part of the
erectile portions of the penis must be plicated.
Other Variations:
Penile torsion consists of a counterclockwise rotation of the glans
penis. This is often seen in association with hypospadias and may be
improved to varying degrees in the course of hypospadias repair. Penile
torsion by itself is rarely of functional significance.
Dorsal preputial hood may be observed in newborns in whom hypospadias
cannot be evaluated without forcible separation of foreskin from glans.
We usually suggest leaving foreskin intact in these newborns and re-examination
in 6 months. By this time there is generally enough separation that
hypospadias can be evaluated, and the family may have some idea by
then if there is chordee.
Webbed penis occurs when scrotum forms the ventral side of penile
shaft.
A buried penis may be hidden by generous suprapubic fat pad.
A concealed penis occurs when preputitial scarring covers the glans.
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