Urethral injury

Urethral injuries range from a mild contusion with preservation of epithelial continuity, to a partial tear of the urethral epithelium, or full urethral transection possibly combined with disruption. Injuries to the urinary tract occur in ≈ 10% of patients who present after blunt or penetrating trauma [1]; not surprisingly these are usually young men aged 15–25 years. Of these injuries a few involve the urethra, with 65% being complete and 35% partial tears [2]. Urethral injuries alone are never life-threatening except as a consequence of their close association with associated pelvic fractures and multiple organ injuries. A significant number of urethral injuries also occur iatrogenically, after urethral instrumentation or penile surgery, usually resulting in partial urethral tears. An appreciation of the anatomical characteristics of both the anterior and posterior urethra is an important prerequisite for both the accurate diagnosis and successful management of urethral injuries. Indeed, for convenience injuries can be subdivided into those affecting either the anterior or posterior urethra, as both sites are exposed to different mechanisms of injury. The male urethra is divided into anterior and posterior sections by the ‘urogenital diaphragm’. The posterior urethra consists of the prostatic and membranous urethra, the latter being enclosed in the ‘urogenital diaphragm’ and extending from the bladder neck to the distal sphincter mechanism for 3 cm. The bladder neck sphincter is functional from the internal meatus down to the level of the verumontanum, and in the male is reliably competent, provided it is not surgically damaged or rendered functionally incompetent by rises in intrinsic detrusor pressure, e.g. related to unstable detrusor contractions. The distal sphincter mechanism is ≈ 2.5 cm long but it is only 3–4 mm thick and forms the whole thickness of the membranous urethra extending upward, through the apical prostatic capsule, to the verumontanum. The competence of this distal urethral mechanism is entirely dependent on the sphincter muscles within this 3–4 mm thickness of the membranous and supramembranous urethra, because there is no periurethral ‘external sphincter’ mechanism either anteriorly or laterally. The traditional description of a complete urogenital diaphragm, enclosing a bulk of striated external sphincter muscle and encircling the membranous urethra, is inaccurate. A ‘potential’ pubo-urethral space lies between the pubic bone and the urethra in the pelvic floor, exactly in the supposed position of the ‘urogenital diaphragm’[3]. This pubo-urethral space is particularly important as even in heavily scarred cases it is easy to develop surgically via a perineal approach after minimal mobilization of the bulbar urethra. The external approach to the membranous urethra and the apex of the prostate that it provides enables the distal extent of the distal sphincter mechanism to be accurately identified and preserved. The anterior urethra consists of the bulbar and penile urethra, and is 15 cm long, extending from the end of the membranous urethra to the external meatus. It is divided into two segments at the level of the penoscrotal junction. Proximal to this is the bulbar urethra, which is the shorter of the two segments and lies in the midline between both penile crura. The distal segment is called the penile or pendulous urethra and lies closely juxtaposed to the two corpora cavernosa. The anterior urethra maintains a fairly constant luminal calibre until its terminal portion, at which point it widens to form the fossa navicularis, narrowing again at the external meatus. Injuries to the anterior urethra occur only a third as often as those to the posterior urethra; they are usually a consequence of direct trauma to the urethra, which is relatively exposed, particularly in its penile portion. ( Table 1). Injuries to the posterior urethra are associated with major and often life-threatening trauma. However, in recent years there has been a relative increase in iatrogenic problems, particularly with the increased use of radical prostatectomy ( Table 1). Whilst the types of injury are self-evident from Table 1 certain aspects of clinical presentation warrant emphasis and discussion. Trauma to the anterior urethra is usually associated with extensive bruising of soft tissues. Unless exploration is mandatory, e.g. in the context of penetrating injury or to carry out debridement or repair of an adjacent structure such as the corpus cavernosum, then the acute management usually begins with antibiotic therapy, followed by catheter drainage as appropriate and surgery of the urethral injury as necessary later. Iatrogenic injuries of the anterior urethra are rare but may occur, especially after circumcision and thus particularly in children. They are of two types; urethrocutaneous fistulae and urethral distortion secondary to partial glans penis amputation. The cosmetic retrieval of patients with this injury was reviewed by Baskin et al.[4] in a series of 11 patients treated using well-established techniques based on surgical principles used in the management of hypospadias surgery. Posterior urethral injuries classically occur in association with pelvic fractures, and are the result of shearing of the prostate from its connection to the apex of the prostate and from the puboprostatic ligaments, which are ruptured. The association of urethral injuries with pelvic fractures is reportedly 3–25% in most studies; 27% are also associated with other intra-abdominal injuries. The incidence of double injuries involving the urethra and the bladder in males is reportedly 10–20%, and may be intraperitoneal (17–39%) or extraperitoneal (56–78%), or rarely both [1]. As the forces involved in pelvic fractures have to be extreme, urethral injuries associated 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. Colapinto and McCallum [5] classified posterior urethral injuries by their radiographic appearances into three types, depending on the integrity of the membranous urethra and extension of the disruption into the bulbar and membranous urethra. Recently, a new anatomical classification was proposed [6], providing a means of comparing treatment strategies and outcomes ( Table 2). Urethral injuries in females are rare as the female urethra is short and mobile with no significant attachments to the pubic bone, thereby rendering it relatively resistant to injury. The reported incidence in females with pelvic fractures is 0–6%[7]; these injuries tend to be caused by lacerations from the bony fragments of the fractured pelvis and vary in severity. In a recent series of 12 patients, an associated rectal injury was reported in 30% of patients, a vaginal injury in 75% and 25% went on to urinary diversion [8]. Whilst these injuries are rare, they are difficult to manage appropriately so that the patient maintains continence. Prolonged obstructed labour can result in ischaemic injury to the urethra and bladder neck, and is relatively common in women in developing countries. Penetrating injuries to the perineum and iatrogenic injuries to the urethra as a result of endoscopic instrumentation or during vaginal surgery are rare if the surgeon is experienced. Urethral injuries in children tend to follow the same mechanism of injury as in adults. Straddle pelvic fractures are more common than in adults [9]. The tear is often in the prostatic urethra or at the bladder neck because of the rudimentary nature of the prostate, and is more likely to be a complete rupture (69% vs 42%). The more proximal the injury, the greater the risk of incontinence, impotence and stricture formation in the long term. Iatrogenic injuries are more significant because of the smaller urethra in the child. In the posterior urethra, iatrogenic injuries are most common in elderly men and are mostly related to surgery involving the prostatic urethra. Predisposing factors to such injuries during TURP include a vascular prostate, prostatic tumours and an inexperienced surgeon. There is an increasing incidence of posterior urethral strictures with the greater use of radical prostatectomy, as a consequence of the development of anastomotic stenoses. Unfortunately, the term ‘posterior urethral stricture’ is still widely used to include simple sphincteric strictures, subprostatic pelvic fracture urethral distraction defects (PFUDDs), and strictures after both prostatectomy for BPH and radical prostatectomy. This is confusing, because all of these groups differ both in aetiology and in the principles of their surgical resolution. Logically, the term ‘urethral stricture’ should be used to indicate a narrowing of the urethral wall caused by intrinsic corpus spongiosum fibrosis (spongiofibrosis) whilst the urethra remains in continuity. Strictures after prostatectomy for BPH are a well recognized complication and can be classified based upon their location, i.e. involving the bladder neck, mid-prostatic fossa and the whole prostatic urethra. As a rule all of these strictures respond well to incision using a Colling's knife, but those involving the whole prostatic urethra do least well at 5 years of follow-up and are more likely to develop complications, with incontinence occurring in 29% of patients after surgery [10]. There is a suggestion that the stricture rate after TURP could be reduced by calibrating the anterior urethra before inserting the resectoscope, but the efficacy of this approach, which sounds very plausible, has yet to be confirmed. After radical prostatectomy the urethra is transected at the proximal extent of the distal sphincter mechanism, with subsequent stricture formation at the site of anastomosis to the bladder neck. However, in PFUDDs there is a traumatic disruption of urethral continuity, usually with minimal loss of urethra, but with displacement of the two ends. Simple continuity strictures of the membranous urethra (both iatrogenic and after localized inflammation) and those occurring after prostatectomy are best referred to as ‘sphincter strictures’ because this emphasizes that although the function is generally impaired to a variable extent, the distal urethral sphincter mechanism has not been destroyed [3]. In contrast, in PFUDDs (in all but the most minimal lesions) the function of the intramural distal urethral sphincter is destroyed by the subprostatic urethral rupture through its mechanism. Apart from the management of the urethral stenosis, sphincter strictures are difficult to deal with as they occur in the of the distal sphincter a be to the intrinsic sphincteric function than the of the stricture They present They are in the only sphincter mechanism that remains after of the bladder neck in prostatectomy. The injury that the distal sphincter and often its subsequent also its functional competence to a greater or They tend to particularly by sphincteric function which to their with a in to urethral continuity, it is to and if necessary functionally the sphincter mechanism at the bladder neck. The diagnosis of urethral injury a of particularly after and should be before a urinary catheter is often by an in the urethral injuries can present with at the to or the development of a perineal or down a of of penile bruising down the is caused by rupture of the to as the This in bruising in the Urethral injury is to be in patient with a fracture of the The risk of urethral injury at the urethral meatus to bladder from to pelvic of bruising of the perineum prostate, although this be difficult to in the of a pelvic fractures involving displacement of the pubic relative to the of the pelvis the of at the external urethral to and a bladder is fairly of urethral a very the external sphincter may not at the meatus and a bladder may be related to a sphincter as a result of than a complete urethral A to a prostate, but and may the of a The is more important as a to for rectal injuries that can be associated with of pelvic fractures on the is of such an injury. of the to the patient external in those with iatrogenic injury the nature of the injury is either at the of surgery and can be with appropriate being at that or during after surgery. The for intra-abdominal urinary tract trauma on the use of if This provides an accurate of the and they are and other intra-abdominal whilst providing no on function and can be difficult to in the of because of is not as as but is to as it provides on the of and can be out with a in the In patients with external is the of if a urethral injury is it should be out with using a which is into the distal urethra and in the fossa of the urethra to the urethra The patient is in a and is as of is into the urethra. is not a series of using of for out in the can be as the patient and a urethral injury be a catheter is and a and later. who surgery for other may be by a and using a as a the same using and urethral have been with of However, this is not for complete of the posterior urethra and the in the anterior urethra are in there is significant stenosis, urethral repair remains the treatment of and are the of in the and of urethral injuries. This is usually out within a of injury if repair is or at 3 if a or repair is is not a in the of urethral but can be in the position of pelvic and the to of a recent in the of there is in using it to urethral injuries and their The is that it is not and it can be used to periurethral The of is still being and it is yet not an form of for urethral strictures in most The management of urethral injuries remains because of the of injury associated injuries and treatment in to the relative of the injuries and the of most The management of all urethral injuries is the resuscitation of the as associated injuries may be This is especially so for posterior urethral because of their close association with pelvic The in acute management is to the nature of the injury and to drainage of the This into and an of the via a or is the treatment of in such as it the of the urethra that is damaged and for a and to be out at a Urethral injury, because it is not be on the of in the management of the urethral injury can only after the patient has been and associated injuries However, after the of urethral injuries tends to more important and management can be of urethral incontinence and impotence predominate in this The principles of urethral repair epithelial of a to the which can surgical bladder neck competence with a posterior urethral involving the distal sphincter The of surgical can be the of and or the integrity of the urethra is in with contusion and repair may be necessary after and subsequent to the In most cases there is a partial rupture of the urethra and it is to the injury to to there is a stricture after at 3 The is for ≈ to urethral is used and the then as if can be then the can be The most important early complication of an acute urethral injury is or from the urethral tear an that can to form an of the on the and can involve the and of these include urethrocutaneous periurethral diagnosis and urinary with the appropriate of the incidence of these In the to term a urethral may However, if the urethra is to in more than of the patients no surgical be necessary strictures can be by either urethral or internal A of these two techniques out was reported in a series of Whilst the patients the of this was that there was no significant between and urethral particularly in patients with a stricture cm long In if there has been a significant urethral injury involving to and loss of corpus and resulting in complete urethral then a urethral is likely to be usually by a simple anastomotic repair of the anterior urethra can be repair should be only to those patients with penetrating urethral injuries who are and with no significant injuries to for simple urethral is The urethral injury is with a with being to of the corpus spongiosum and to subsequent The patient is and the urethra through a incision if there is penile injury, and via a midline perineal incision if there is a bulbar urethral injury. the site of injury is necessary debridement is and the urethra is both and urethral are and an anastomosis a a catheter is also to the urethral The repair site can be and subsequent anastomotic by the of the corpus spongiosum to that of the corpus and a are also in and after surgery. After a is with the urethral catheter in and provided that there is no at the anastomotic the urethral catheter can be there is then the catheter is for and the a later. at the of exploration the urethra is to be so that anastomosis is not then the injury should be and the urethra to a urethral repair with proximal as or a the of such a A is usually out at least 3 after injury. repair via a direct anastomotic is appropriate for defects of to cm in the urethra and of cm in the penile urethra. defects urethral with or Posterior urethral injuries vary in and extent, and and in their can in most cases be by urethral drainage or by and subsequent internal or urethral for partial are short and are with no surgery. As the is at the 12 that the best site for is between the 3 and this a subsequent if it There is a in the extent of sphincter associated with sphincter extreme, a sphincter stricture is the result of simple and of its epithelial the sphincter mechanism may be and so a distal it can be to a calibre of with no significant of urinary the other sphincter strictures are generally associated with sphincter that is so that even the simple of a may it and the patient [3]. there are between these and these are identified by the result of of the urethra, using simple of the its identified by appropriate the treatment for the more stricture is this is best by the patient to a soft catheter as as necessary to an There are associated with a sphincter stricture by internal particularly as the bladder neck mechanism is not functional as a consequence of the prostatectomy. a patient is not rendered as a result of the mm thickness of the intramural distal sphincter mechanism, secondary fibrosis may a mechanism into that is and relatively to deal After and a patient with a sphincter stricture that is difficult to manage by may to the risk of incontinence involved with a repair This is especially so as the bladder neck is with subsequent of an if necessary urethral are after the urethra is exposed and the urethral to As a of the range of for different is for such surgery. repair of posterior urethral injuries is usually associated with a incidence of subsequent strictures, incontinence and factors include the in and as a result of formation and also mobilization and subsequent surgical et reviewed the in a in which at the patients in 15 reported They that urethral was associated with a rate of impotence in and incontinence in and reported a series of patients who endoscopic urethral within of injury. a follow-up of of mild incontinence and strictures after of these short strictures by of these patients a of subsequent which The series reviewed by et which may the than those reported by and there was no et reported a series of they the urethra in 11 using urethral within 11 of injury. Of the patients for strictures which treated by Whilst there no associated with this there few patients and the follow-up was 1 The of these techniques reviewed by in a series of patients combined with a of patients reported and early was associated with a stricture a incontinence rate and a impotence was associated with a stricture a incontinence rate and a impotence a catheter with a to a subsequent repair was not surprisingly associated with a stricture but was than and early with a incontinence rate and a impotence There are very few on the series being that by with than patients. The of early management is not to a stricture occurring but to that if it it is The most common of a subprostatic urethral injury by repair is the development of a urethral the of which there is also and a This has the of using endoscopic reviewed with patients and that with a years of ≈ of patients by the endoscopic and 10% to The major of this series to the short follow-up and the that if there is a significant there be an between the two of urethra, which is then to A to the in of an endoscopic tract which is in the and a this is into the bladder and subsequent surgical repair by a than a perineal In a of this approach, reported a series of patients treated using a a penile is after reported a there was a after which there was a rate in and 75% in treated within 3 of injury. on a of the it is that urethral repair for at a of 3 after trauma using a perineal approach remains the This has the that most associated damaged and and the pelvic have by such a simple can be by a anastomotic provided it is not associated with extensive and that the bladder neck mechanism is and Whilst the management is to that for anterior urethral surgery, and that more can be appropriate the principles of such surgery are After the bulbar urethra the subprostatic mobilization of a bulbar urethra to the of the penis generally cm of which is usually to a anastomosis to the apical prostatic urethra after a of cm. to this include the corpora in the midline and an to both increase surgical and the urethral the is than as a result of a of the prostate or the of the bulbar urethra has been by from a surgical it may be necessary to the bulbar urethra, the penile on to it to be to a It is rarely necessary to the whole of the to for a anastomosis from A partial of its posterior with a is usually for the rare of pubic the for urethral is the only for a In most a perineal approach if the bladder neck is provides with no to to surgery. Urethral using a perineal anastomotic A repair using this anastomotic has a rate of ≈ at years and the risk of such as impotence or incontinence occurring as a consequence of the surgery in is series in children have been In a series of not very successful whilst both perineal and successful in and of [9]. In a series of children treated by either or anastomotic The incidence of surgery the greater to of the bladder neck in children. The bladder neck may be damaged by a pelvic fracture injury, but the most common of its is the of an mechanism by the of an extensive pelvic In such it is usually to its functional competence by it by of the fibrosis it to the anteriorly and laterally. the of this on secondary fibrosis by the with a which the functional of the sphincter mechanism. in most patients the integrity of the bladder neck mechanism is not difficult to but on via the combined with a via a to there is a of the bladder neck, functional or other associated such as a The mechanism may be damaged by pelvic fracture injuries that do not result in urethral injury. The incidence is the urethra is and the prostate is the are close to the subprostatic urethra, and are within the perineal it is that most subprostatic are associated with of injury to the mechanisms of of they result in an of or Indeed, the of impotence by has that after pelvic fracture is more often the result of to the than to the vascular mechanisms or in the of a secondary fibrosis the apex of the prostate carry risk of to associated with the injury, particularly if it or of the the apex of the A anterior approach to surgical in this is A is to be of the incidence of significant associated with during surgery. There are than cases reported in the the all associated with the but few have not this Whilst this complication to be associated with its is likely to be factors include localized muscle from and of these factors are likely to result in a in with to and of through muscle the increasing the and in the A recent series of patients reported an incidence of two such cases It is important to be that this may occur, particularly if the patient has an as this may the and thereby the which are Urethral injury, whilst is an important of It often has significant either in with iatrogenic or upon trauma the injury is usually the of In of the relative of significant urethral injury in it is important to be of the principles of management in the of The