The urethra in the pubic phalloplasty is
fashioned out of hairless labia majora and vestibular
skin. One side is mobilised and incorporated in the phallus and the opposite
side forms the perineal
(perineum)
urethra to gain continuity to the patients’ native urethra.
The fistula rate when the urethra was
fashioned in one stage was 95% but this has been reduced in the two stage
urethroplasty to 60%. In this technique the fistula is usually located at
the junction of the native urethra with the neourethra and this is likely to
be caused by an overlap of the suture line.
With this high fistula rate changes have
been made to the technique of closure of the perineal urethra. Firstly, a
martius fat pad is taken from the labia majora and mobilised to cover the
entire suture line so that there is no apposition
of subsequent sutures during the three layer closure. Since this has been
performed the fistula rate has been drastically reduced.
The other feature that has been changed is
that urethral catheters were previously left in situ for approximately three
weeks to allow healing to occur and it is the impression that this is
unnecessary. Consequently now the phallic urethra is fashioned and once this
is stabilised and shown to be patent
the perineal urethra is then formed and a urethral stent
left in situ for approximately five days with a covering suprapubic
catheter.
A urethrogram
is then performed at three weeks and this too has reduced the fistual rate.
Alternative techniques to prevent fistulae have been the use of an anterior
vaginal flap which is mobilised and sutured to the vestibular skin.
This with a combination of the Martius fat
pad reduces further suture line apposition and and consequent urethral
fistula formation. Urethral fistulae may also occur with the radial forearm
flap phalloplasty. This is likely to be due to ischaemia of the urethral
skin at the junction of the native and neourethra.
In all phalloplasty techniques, providing
there is no distal urethral obstruction, a simple repair with great care to
avoid suture apposition and the use of healthy vascular
tissue usually result in a successful closure.
Urethral strictures occur commonly in all
phalloplasty procedures due to ischaemic
necrosis of the
tissue that has been used. With the forearm flap phalloplasty the stricture
rate depends on the position of the Urethral strip.
The stricture rate is less if the urethra
is centrally based over the radial
artery and more of a problem when the strip is harvested from the hairless
kin of the ulnar border of the forearm. Strictures with this technique may
occur anywhere along the pendulous urethra but more commonly at the junction
of the skin tube to the perneal neourethra, particularly is spatulation has
been inadequate. In the pubic phalloplasty, urethral strictures commonly
occur at the meatus.
This is due to ischaemic necrosis of the mobilsed labial flap.
The flap is based on the clitoral blood
supply and consequently the most distal
areas are prone to ischaemia. Strictures in other areas using this technique
are rare as the labial and vestibular skin makes an ideal urethral
substitute.
Many treatment options have been used to
treat these urethral stricutes to include repeated dilation, urethrotomy, meatoplasty
and urethroplasty. It is common for patients to perform self meatal dilation
in the pubic phalloplasty though it is clear that a longstanding cure using
dilation is unlikely.
Other patients will maintain a small
urethral stent in the meatus to direct the stream and to prevent restricture.
Recurrence after urethrotomy is also the rule and a permanent cure can only
be achieved by a formal meatoplasty or urethroplasty depending on the
position of the stricture.
It is also important that a minimal number
of re-operations be performed as multiple procedures are likely to disfigure
the cosmetic appearance of the phallus. Urethroplasties using a split skin
graft and pedicled island skin flaps have so far been unsuccessful. Great
advances have however been achieved using free grafts of buccal
mucosa.
The buccal mucosa is harvested from the
inner cheek but for longer flaps extension to the lower lip can be
performed. It is important that the graft is thin to increase the chance of
being viable and therefore it should be de-fatted before being used. It is
an ideal substitute as it used to being permanently wet, unlike the use of
skin. It can be used as a patch or tubed over a catheter with spatulations
at both ends: however tubed grafts are more likely to develop anastomotic
strictures. Many recipient beds have been used. Where there is a meatal stenosis
the penis is opened through the original incision and cut down to healthy
vascular neourethra.
This scar tissue base seems to have a
reasonable vascularity to accept the buccal graft. Where patients have had
an absence of the urethra a catheter has been inserted intially, left for
three weeks to allow granulation
tissue to form and this granulation
tissue bed used for a long tubed buccal graft.
Occasionally two segments of buccal graft
harvested from both cheeks can be used although at the junction of the two
tubes anastomotic stricture may occur. Therefore with longer tubes it may be
necessary to harvest the buccal mucosa in one segment extending from one
cheek to around the lower lip and on to the other side.
The buccal donor area is closed primarily
with catgut and after three weeks the scar is very difficult to see. There
is minimal morbidity from the donor site area and patients are recommended
to start eating the following day.
Other techniques using buccal mucosa
include an onlay. Here the skin can be de-epithelialised
to leave the dermal
tissue bed with is an excellent recipient of the buccal graft.
After a three month period to allow
contraction this area can then be tubed as a second stage.
anastomosis: a
communication between or coalescence of blood vessels; the surgical union of
parts and esp. hollow tubular parts anterior adjective 1: relating to or
situated near or toward the head or toward the part in headless animals most
nearly corresponding to the head 2: situated toward the front of the body. back
apposition: the
placing of things in juxtaposition or proximity. back
buccal: of, relating
to, near, involving, or supplying a cheek. back
catheter: a tubular
medical device for insertion into canals, vessels, passageways, or body
cavities usu. to permit injection or withdrawal of fluids or to keep a
passage open. back
dermis: the sensitive
vascular inner mesodermic layer of the skin. back
distal: situated away
from the point of attachment or origin or a central point: as located away
from the center of the body. back
epithelium: a
membranous cellular tissue that covers a free surface or lines a tube or
cavity of an animal body and serves esp. to enclose and protect the other
parts of the body, to produce secretions and excretions, and to function in
assimilation. back
fistula: an abnormal
passage leading from an abscess or hollow organ to the body surface or from
one hollow organ to another and permitting passage of fluids or secretions. back
granulation: one
of the minute red granules made up of loops of newly formed capillaries that
form on a raw surface (as of a wound) and that with fibroblasts are the
active agents in the process of healing. back
granulation
tissue: tissue made up of granulations that temporarily replaces lost tissue
in a wound. back
ischemia: localized
tissue anemia due to obstruction of the inflow of arterial blood junction
noun : a place or point of meeting. back
meatoplasty:
plastic surgery of a meatus. back
meatus:
<urethral>. back
micturition:
urination. back
necrosis: death of
living tissue. back
patent: affording free
passage; being open and unobstructed. back
perineal: of or
relating to the perineum. back
perineum: the area
between the anus and the posterior part of the external genitalia esp. in
the female. back
phalloplasty:
plastic surgery of the penis or scrotum back
radial: of, relating
to, or situated near the radius or the thumb side of the hand or forearm. back
stenosis: a
narrowing or constriction of the diameter of a bodily passage or orifice. back
stent: a mold formed
from a resinous compound and used for holding a surgical graft in place. back
stricture: an
abnormal narrowing of a bodily passage (as from inflammation, cancer, or the
formation of scar tissue) <esophageal ~> : the narrowed part. back
suprapubic:
situated, occurring, or performed from above the pubis. back
urethra: the canal
that in most mammals carries off the urine from the bladder and in the male
serves also as a genital duct. back
urethrogram: a
roentgenogram of the urethra made after injection of a radiopaque substance.
back
vascular: of,
relating to, constituting, or affecting a tube or a system of tubes for the
conveyance of a body fluid (as blood or lymph). back
vestibule: any of
various bodily cavities esp. when serving as or resembling an entrance to
some other cavity or space: as the space between the labia minora containing
the orifice of the urethra. back
