Injuries to the male urethra
Rupture of the
bulbar urethra
Rupture of the bulbar urethra is the most
common urethral injury. There is a history of a blow to the perineum usually due
to a fall astride a projecting object. In the days of sailing ships, the common
cause was falling astride a spar; the modern equivalent is seen among workers
losing their footing on scaffolding. Cycling accidents, loose manhole covers (Fig.
67.4) and gymnasium accidents astride the beam account for a number of
cases.
Clinical
features
The triad of signs of a ruptured bulbar
urethra is retention of urine, perineal haematoma and bleeding from the external
urinary meatus.
Preliminary
assessment and treatment
The patient will be in pain and should be
treated with appropriate analgesic drugs. He should be discouraged from passing
urine if rupture of the urethra is suspected. Instead, if the bladder is full, a
simple percutaneous suprapubic puncture should be performed and a fine catheter
inserted to drain (Fig. 67.5). This
will reduce the likelihood of urinary extravasation and allow appropriate
investigations to establish ii full extent of the urethral injury. If the
patient has already passed urine when first seen and there is no extravasation
the rupture, if any, is partial and a catheter is not needed. either case, it
is probably wise to administer a course prophylactic antibiotics.
Treatment. The initial management of bulbar
urethral injuries has been controversial but a consensus is emerging. The main
worry is the injudicious urethral catheterisation will convert a partial tear
into a complete transection of the urethra. The initial treatment described
above to be recommended for most of those who go into urinary retention after the
accident, especially if there is bleeding from the urethra. Mo information may
be obtained by an ascending urethrogram or even flexible cystoscopy to assess
the injury. Very occasionally, if the facilities for passing a percutaneous
suprapubic catheter are not available, it may be permissible to try to pass a
soft, small-calibre urethral catheter with
force. This may allow a few patients to avoid the open placement of
suprapubic tube into the bladder.
If
investigations show a complete tear of the urethra, the suprapubic catheter should
be left in place until arrangements can be made to repair it. Some surgeons
advocate early open repair of the urethra with excision of the traumatised
section and spatulated end-to-end reanastomosis the urethra (Fig.
67.6). Others
wait longer before embarking upon repair operation but may attempt to find a way
across the gap in the urethra using a urethroscope. This allows a urethral
catheter to be place so that the alignment of the urethra is as near as possible
to normal when healing occurs.
Complications
Subcutaneous
extravasation of urine occurs in complete rupture if the patient attempts to pass urine.
Stricture is a common sequel to urethral trauma, whether there is a partial or
complete tear or simply periurethral bruising. Infection may also play a part.
Rupture of the
membranous urethra
Extra
peritoneal rupture of the urethra
Intrapelvic rupture of the membranous urethra
occurs near the apex of the prostate (Fig. 67.7). Like extraperitoneal rupture
of the bladder, it may be due to penetrating wounds but in civilian life it is
most usually a result of pelvic fracture.
Fracture of the pubic and ischial rami is most
likely to result when sudden force is applied to one lower limb in a car
accident or in landing on one leg after falling from a height. There is an
associated disruption of the sacroiliac joint so that one half of the pelvis and
ischiopubic ramus is pushed up above the other. This applies a traction force on
the prostate which is firmly bound by ligaments to the back of the symphysis
pubis. The torn ends of the urethra may be widely displaced by this type of
injury.
In
another type of pelvic fracture the patient suffers a front-to-back compression
of the pelvis in a blow directly from the front. A ‘butterfly fracture’ of
the pubic rami on each side occurs. When the compressive force is relieved, the
pubic fragment springs back so that the ends of the torn urethra are close to
each other. About 10—15 per cent of cases of fractured pelvis have associated
urethral injury.
Clinical
features
The most common causes of pelvic fracture are
road traffic accidents, severe crush injuries and falls.. There is often
multiple
trauma with injury to the head, thorax and abdomen, and fracture of long bones.
Often the management of these injuries must take precedence and the over-riding
priority is to keep the patient alive by appropriate resuscitation.
The
urethral injury can be managed in the short term by inserting a suprapubic
catheter, and this should be done as soon as it is practicable. The type of
urethral injury can often be deduced from the plain radiograph — a major
urethral disruption is almost certain if there is significant displacement of
the pubic bones. If the prostate is displaced, it may be impossible to reach or
appear to be very ‘high’ on rectal examination. An ascending urethrogram may
be justified if there is doubt.
Stricture. The main complication of urethral
trauma is urethral stricture. When the injury is severe and the disrupted ends
of the urethra are far apart the stricture is likely to be very difficult to
treat. Because of this -worry, some surgeons urge that an attempt should be made
to realign the urethra as soon as the emergency is over and the patient is well
enough to be taken to theatre. Often the orthopaedic surgeons will want to
improve the position of the pelvic fragments at this stage with the possibility
of external fixation. In some cases a urethral catheter can be inserted if a way
through the stricture can be found with a flexible or rigid urethroscope. In
others an open repair of the urethra can be attempted. Other surgeons feel that
it is better to allow a longer period of recovery before attempting to correct
the urethral injury.
If
the urethra is relatively well aligned, an established urethral stricture
may be treatable by optical urethrotomy (Sachse) but many of these patients need
a full-scale urethroplasty. Sometimes the ends of the urethra are widely
displaced and there is extensive fibrosis and even ectopic calcification where
the urethra should be. Occasionally there is such a gap that the ends can only
be brought together by cutting away the pubic bone. The management of a severe
urethral stricture should be in the hands of a specialist urologist.
Urinary
incontinence. If the external urethral sphincter is destroyed, continence of
urine will depend upon the competence of the bladder neck mechanism. Subsequent
surgical manoeuvres such as prostatectomy which destroy the bladder neck may
cause incontinence.
Impotence.
Erectile impotence is common after pelvic fracture with urethral injury. It is
assumed that this is the result of damage to the nerve supply of the penis. The
patients are usually able to achieve erection with prostaglandin injections or a
vacuum device.
Orthopaedic
For management of the fractured pelvis, see
Chapter 21 on ‘Fractures and dislocations’.