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. There may be associated injury to the bladder with either an intraperitoneal or extraperitoneal rupture. The former is associated with the onset of peritonitis and if suspected demands exploration and repair of the bladder even if laparotomy is not indicated by other injuries. Extraperitoneal rupture of the bladder causes symptoms which are difficult to distinguish from those of rupture of the membranous urethra. There is pain, bruising and dullness to percussion above the umbilicus. If there is a significant bladder rupture it must be repaired, a suprapubic catheter inserted and the retroperitoneal space drained.

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’.