1、Urethral injuries,Introduction,Urological injuries occur in approximately 10% of patients who present following blunt or penetrating trauma Of these, a number involve the urethra:65% are complete and 35% partial Urethral injuries by themselves are never life-threatening, except. It is of no surprise
2、 that the highest incidence of urethral injuries is in adults aged 15-25 years.,Urethral injuries can range from a mild contusion with preservation of epithelial continuity, to a partial tear of the urethral epithelium or a full urethral transection and disruption. They can also be classified by sit
3、e into anterior urethral injuries and posterior urethral injuries, which is probably the best way to consider them, since both sites are exposed to different mechanisms of injury.,Anatomy,The male urethra is divided into the anterior and posterior sections by the so-called urogenital diaphragm. The
4、posterior urethra consists of the prostatic and the membranous urethra The latter is enclosed in the urogenital diaphragm. It extends from the bladder neck to the distal sphincter mechanism for a length of 3 cm.The anterior urethra consists of the bulbar and penile urethra and is a 15 cm canal exten
5、ding from the end of the membranous urethra to the external meatus.,The bladder-neck sphincter is functional from the internal meatus doun to the level of the verumontanum,in males it is reliably comptent , provided it is notsurgically damaged or rendered incompetent by unstable detrusor contraction
6、s. The distal sphincter mechanism is about 2.5 cm long, but it is only 3-4 mm thick; it forms the whole thickness of the membranous urethra and extends upwards, through the apical prostatic capsule, to the verumontanum. The competence of this distal urethral mechanism is, in fact, entirely dependent
7、 on the sphincter muscles within the 3-4mm.,Anterior urethral injuries,Straddle injury,Posterior urethral injuries,Unfortunately, the term posterior urethral stricture is still widely used to include simple sphincter strictures, subprostatec pelvic fracture urethral distraction defects, and strictur
8、es following radical prostatectomy. This is confusing because they and the principles of their surgical resolution are entirely different.,Urethral injuries associated with pelvic fractures,Pelvic fractures are commonly caused by road traffic accidents, crush injuries or falls from a height, and mos
9、t commonly occur in young men. Posterior urethral injuries classically occur in association with pelvic fractures and are the result of shearing of the prostate from its connection to the anterior urethra at the apex of the prostate.,Between 3% and 25% of urethral injuries are said to be caused by p
10、elvic fractures. About 27% are also associated with other intra-abdominal injuries. The incidence of double injuries involving the urethra and the baldder ranges between 10% and 20% of males; these may be intraperitoneal(17-39%) or extraperitoneal (56-78%), or sometimes both,Because the forces invol
11、ved in pelvic fractures have to be extremely great, urethral injuries assoviated with pelvic fractures tend to be associated with multiple and life-threatening injuries.Attention to resuscitation tends to predominate in the early management of these patients,Diagnosis of urethral injury,The diagnosi
12、s of any urethral injuries requires a high index of suspicion, particularly in the trauma patient, should be excluded before a urinary catheter is inserted, often by an experienced person in the emergency service.,Anterior urethral injuries can present with blood at the meatus inability to pass wate
13、r, the rapid development of a perineal urinoma or heamatoma forming down a sleeve of Bucks fascia.,Urethral injury is to be suspected in any patient with a fracture of the pelvis. The risk of urethral injury increases with blood at the urethral meatus; difficult-ties/inability to void; pelvic haemat
14、oma; characteristic butterfly pattern of bruising of the perineum; high riding pristate (although this might be difficult to appreciate in the presence of a pelvic haematoma); and fractures involving displacement of the pubic rami relative to the rest of the pelvis.,Although the classic trad of bloo
15、d at the external urethral meatus, inability to pass urine and a distended bladder is fairly indicative of urethral injuries, it must be noted that a very high lesion above the external sphincter may not produce blood at the meatus and a distended bladder may be related to a sphincter spasm as a res
16、ult of pain rather than a complete urethral rupture. Rectal examination helps to exclude a dislocated prostate but swilling and oedema may mask the presence of a normally positioned prostate. Rectal examination is more important as a tool to screen ofr rectal injuries, which can be associated with 5
17、% of pelvic fractures.Blood on the examination finger is highly suggestive of such an inuury.,Urethrocystography,Urethrocystography is the investigation of choice if a urethral injury is suspected.,If the patient develops retention and a urethral injury cannot be excluded, a suprapubic catheter is i
18、nserted and a simultaneous cystogram and ascending urethrogram can be carried out at a later date. An endoscope examination by a trained and experienced urologist using a cystourethroscope can be performed as a preliminary procedure.,Simultaneous suprapubic cystography and ascending urethrograms-the
19、 so-called up-and-downogram-are the investigation of choice in assessing the site, severity and length of urethral injuries. This is usually done within a week of injury if delayed primary repair is contemplated or at 3 months if a delayed or late repair is considered. Ultrasonography is not a routi
20、ne investigation in the initial assessment of urethral injuries but can be useful in determining the position of the pelvic haematomas.,The first choice for the evaluation of intra-abdominal urinary tract trauma relies upon the use of computerized tomography scanning or spiral computerized tomograph
21、y . Ultrasound, although it provides renal imaging, does not give any information on renal function and can be difficult to interpret in the preserce of ileus because of gas distended bowel loops. Intravenous urography is a second best to computerized tomography but is preferable to ultrasound, sinc
22、e it provides information on the renal excretion of contrast and can be performed with a single abdominal film in the emergency room,Management of urethral injuries,Management of urethral injuries remains controversial because of the variety of injury patterns, associated injuries and treatment opti
23、ons available, in addition to the relative rarity of the injuries and hence the limited experience of most urologists. The initial management of all urethral injuries is resuscitation of the patient as a result of associated, Possibly life-threatening, injuries. This is particularly the case for pos
24、terior urethral injuries.,The next step in acute management is to obtain drainage of the bladder. This will prevent further extravasation into surrounding tissues and allow assessment of the urine output. Suprapubic cystostomy by a percutaneous or open route is the treatment of choice in such a situ
25、ation, since it bypasses the area of the urethra that is damaged and allows for a simultaneous study to be carried out at a later date.,Definitive surgical intervention can be considered under the headings of mmediate treatment, delayed primary treatment (10-14 days) and alte treatments(3 months or
26、more).,Primary urethral repair technique,Immediate urethral repair can be attempted if the injury is complete anterior, penetrating or open, provided the patient is stable and the haematoma minimal. Immediate repair of the acutely traumatized anterior urethra can be technically difficult. It should
27、be restricted to only those patients with penetrating urethral injuries who are haemodynamically stable without any significant injuries to non-genital organs, for whom simple urethral closure can be performed. These include defects of up to 2 cm in the bulbous urethra and 1.5 cm in the penile ureth
28、ra.,Longer defects require urethral replacement with grafts or flaps and should be avoided in the acute trauma setting. Both urethral ends are spatulated and an overlapped anastomosis is completed over a 12/14 French catheter; a suprapubic catheter is also essential to guard the urethral repair. At
29、10 days to 2 weeks , a cystourethrogram is obtained with the urethral catheter in situ and provided that there is no leakage at the anatomotic site the urethral catheter can be removed. If there is leakage then the catheter is left longer and the X-ray study repeated a week later.,A delayed elective
30、 procedure is usually carried out a minimum of 3 months after injury. Complete posterior urethral ruptures can be managed by immediate repair, delayed primary urethroplasty, or late urethroplasty.,Immediate open repair of posterior urethral injuries is usually associated with a higher incidence of s
31、trictures, incontinence and impotence. Difficulty in identifying structures and planes as a result of haematoma formation and oedema also hamper adequate mobilization and subsequent surgical apposition. Webster et al. reviewed the world literature, which at the time included 301 patients in 15 repor
32、ted series, and concluded that urethral realignment was associated with restricture in 60%, impotence in 44% and incontinence in 20% of cases.,More recently, Elliot and Barrett 13 have reported an a series of 57 patients who underwent primary endoscopic urethral realignment with a mean follow-up of
33、10.5 rears.Twenty-one per cent had some degree of erectile dysfunction, 3.7% had mild stress incontinence, 685 had post alignment strctures; 13 of these required a total of 20 procedures under general anaesthesia.,The results of the various techniques are reviewed by Koraitim in a personal series of
34、 100 patients combined with a review of 771 patients from published reports.Immediate and early realignment (n=326) was associated with a 535 stricture rate, a 5% incontinence rate and a 36% impotence rate. Primary suturing (n=37) was associated with a 49% stricture rate, a 21% incontinence rate and
35、 a 565 impotence rate. In comparison, inserting a suprapubic catheter before a delayed repair (n=508) was associated with a 97% stricture rate, a 45 incontinence rate and a 19% impotence rate.,On the basis of such evidence it is evident that delayed urethral repairs at a minimum of 3 months after tr
36、auma, using a one-stage perineal approach, remain the gold standard. This technique has the advantage that most associated injuries and damaged skin and tissues, in addition to the pelvic haematoma, have resolved by the time it is performed. The only problem with this approach is the distraction gap
37、 that is present and the length of time the patient has to have a suprapubic catheter before receiving definitive treatment.,In the majority of instances (90%) a perineal approach (particularly if the bladder neck is functioning adequately) provides sufficient access without the need to proceed to a
38、bdominal surgery. Urethral repairs using a one-stage perineal anastomotic urethroplasty give excellent results. Delayed repair has a restenosis rate of approximately 12% at 10 years and the risk of complications such as impotence or incontinence. Occurring as a consequence of the surgery in experienced hands is low,The erectile mechanism may be damaged by pelvic fracture injuries that do not result in urethral injury. The incidence is higher when the urethra is ruptured and much higher when the prostate is grossly dislocated.,
