Posterior urethral injuries and management

INTRODUCTION — Any blunt or penetrating trauma to the penis, scrotum, perineum, or pelvis may cause injury to the urethra. Urethral injuries are much less common in females because the urethra is short, relatively mobile, and lacks significant attachment to the pubis. The male urethra is divided into the anterior (bulbous and pendulous) and posterior (prostatic and membranous) urethra (figure 1) at the level of the urogenital diaphragm. Anterior urethral injuries may be caused by direct blows, straddle injuries, instrumentation, or penile fracture. By contrast, posterior urethral injuries usually occur in the setting of significant pelvic fractures, often caused by motor vehicle collisions or crush injuries (table 1). (See "Pelvic trauma: Initial evaluation and management" and "Severe pelvic fracture in the adult trauma patient".)

In this topic, we will concentrate on posterior urethral injuries, including their etiology, clinical manifestations, diagnostic evaluation, and management. The etiology and management of anterior urethral injuries and other traumatic injuries of the lower genitourinary tract are discussed separately. (See "Overview of traumatic lower genitourinary tract injury" and "Traumatic injury to the male anterior urethra, scrotum, and penis" and "Strictures of the adult male urethra".)

EPIDEMIOLOGY AND ETIOLOGY — Traumatic injury to the posterior (prostatomembranous) urethra occurs in 10 percent of pelvic fractures [1]. Blunt trauma from motor vehicle accidents or occupational injuries account for at least 90 percent of the cases, but penetrating trauma can cause these injuries as well [2,3]. A review from the United Kingdom noted that these types of injuries are more pronounced in motorcycle accidents in which 81 percent of urethral injuries are associated with pelvic fracture [4].

The urethra is most often injured with fractures that disrupt the pelvic region or cause diastasis of the pubic symphysis [5,6]. The risk of urethral injury varies with the type of pelvic fractures (figure 2 and table 2) [6-10]. High-risk injuries include concomitant fractures of all four pubic rami or fractures of both ipsilateral rami accompanied by massive posterior disruption through the sacrum, sacroiliac joint, or ilium. Low-risk injuries include single ramus fractures and ipsilateral rami fractures without posterior ring disruption. The risk of urethral injury approaches zero with isolated fractures of the acetabulum, ilium, and sacrum [1].

Posterior urethral disruption occurs when a significant pelvic fracture causes upward displacement of the bladder and prostate. Avulsion of the puboprostatic ligament is followed by stretching of the membranous urethra resulting in a partial or complete disruption at the anatomic weak point, the bulbomembranous junction [1].

The magnitude of injury determines the length of the ultimate defect, ranging from elongation to complete transection of the urethra, with transection occurring in most cases. In the least severe cases, there may be elongation of the membranous urethra as the prostatic apex is separated from the pelvic floor, with resultant hematoma pushing the bladder base up into the pelvis. This typically results in fibrosis of the injured area and narrowing of the urethra but rarely in obstructive scar tissue. When the injury is more severe, the prostatic apex actually tears away from the urethra with scar formation in the injured area. Thus, the resulting "stricture" is technically a distraction defect (not a laceration or transection), with no lumen communicating between the urethral ends [11]. Most urethral injuries that occur with a pelvic fracture are distraction defects with minor separations. Very severe trauma may result in wide separation of the urethral ends along with concomitant injuries to the bladder or rectum, which may be seen in up to 18 percent of cases [12]. (See 'Grade of injury' below.)

CLINICAL MANIFESTATIONS — The following clinical symptoms and signs should raise suspicion for a urethral injury [13]:

●Any apparent injury to the penis, scrotum, peritoneum, or the lower abdomen, either blunt or penetrating.

●Presence of blood at the urethral meatus.

●Inability to urinate in the emergency room.

●Presence of a perineal hematoma.

●A high-riding prostate on digital rectal examination.

DIAGNOSTIC EVALUATION — A retrograde urethrogram (RUG) and cystogram are required in any patient with blood at the meatus or difficulty urinating after experiencing blunt or penetrating injuries in the vicinity of the genitalia and lower abdomen. RUGs should also be performed liberally in patients with injury to the penis, scrotum, and perineum [14]. The 2020 American Urological Association Urotrauma guidelines specifically state that a RUG should be performed immediately in cases of pelvic trauma and blood at the meatus [15]. If no extravasation is seen, a Foley catheter may be inserted and a cystogram or upper tract study taken as indicated. (See "Blunt genitourinary trauma: Initial evaluation and management", section on 'Primary evaluation and management'.)

The only situation in which a RUG should be deferred is when significant pelvic vascular injury is suspected and/or pelvic angiography may be indicated. This is because assessment for potentially life-threatening bleeding takes precedence and the contrast used to perform a RUG may interfere with the interpretation of a pelvic angiogram or computed tomography (CT) scan. (See "Blunt genitourinary trauma: Initial evaluation and management", section on 'History, examination, and approach to testing'.)

For patients with combined pelvic fracture and urethral injury who require drainage of the bladder urgently during the initial trauma evaluation but RUG cannot be immediately performed, guidelines from the American Urologic Association in both urotrauma [15], and urethral stricture disease [16] support placement of an open or percutaneous suprapubic tube as the preferred method of immediately draining the bladder [15]. The suprapubic tube can help to facilitate the diagnostic evaluation and aids in treatment of the pelvic fracture associated urethral injury with either delayed, definitive urethroplasty as the preferred choice or primary endoscopic realignment.

Retrograde urethrogram — A well-performed RUG is key to the accurate diagnosis and classification of urethral injuries and is imperative to assessing the extent of injury and planning surgical repair. While other imaging modalities have been investigated for utility in diagnosis and surgical planning, such as magnetic resonance imaging [17], RUG is the primary test used to evaluate the integrity of the urethra in patients with a suspected injury. It is fairly simple and straightforward to perform but does require planning in order to obtain a good study.

The RUG should be obtained with the patient positioned in a semi-oblique position, rotated approximately 30° (figure 3). Many injuries in the posterior urethra and proximal bulbar urethra can be missed on an anterior-posterior film. A scout film should be performed in this position to allow visualization of the entire urethra (image 1). To verify that the patient has been appropriately positioned, the obturator fossa should be obliterated on the scout film. The patient should be kept still to avoid potentially disrupting a stable pelvic hematoma. A 60 mL catheter-tip syringe should be filled with a mixture of 40 mL of water-soluble contrast and 10 mL of viscus lidocaine. Attach the syringe to a sterile Christmas tree adapter, if available.

Using sterile techniques, the tip of the penis is then prepped, and a 4 x 4 sterile gauze is placed under the tip of the penis. The tip of the Christmas tree adapter is placed inside the meatus of the penis, and the glans of the penis is grasped with the nondominant hand. The adapter should be inserted snugly into the urethral meatus to ensure a tight fit as leaking contrast could result in a spurious study. The contrast solution is then injected into the penis in a retrograde fashion. If no Christmas tree adapter is available, injecting the fluid directly from the tip of a catheter-tip syringe is acceptable. Alternatively, insert a Foley catheter a few centimeters into the urethra and partially inflate the balloon to ensure a snug fit within the fossa navicularis. Attach the catheter-tip syringe to the Foley catheter and inject the contrast.

Under fluoroscopy, the penis is then bent downward in order to view the location of the suspensory ligament of the penis. Contrast is injected into the penis until it fills the entire urethra and a small amount can be seen entering into the bladder. The patient then is allowed to void in the same position showing complete emptying of the contrast from the system, thus providing a voiding phase of the RUG. If fluoroscopy is not available, plain radiographs can be used (image 2). In that case, inject 50 to 60 mL (0.6 mL/kg in children) of contrast before obtaining a plain film while injecting the final 10 mL.

Contrast entering the bladder without extravasating through the urethra defines a normal RUG. A partial disruption is demonstrated by urethral extravasation accompanied by some contrast entering the bladder. A complete disruption results in urethral extravasation without any contrast entering the bladder. (See 'Grade of injury' below.)

DIAGNOSIS — A urethral injury should be suspected in patients with penetrating or blunt trauma to the genitalia or lower abdomen, or a significant pelvic fracture, accompanied by one or more of the clinical symptoms or signs described above (eg, blood at meatus). Such patients should undergo a retrograde urethrogram (RUG), which is usually diagnostic of the urethral injury and establishes the injury grade.

Grade of injury — A urethral injury scale has been established by the American Association for the Surgery of Trauma (AAST) (table 3)[18]. The urethral injury scale emphasized the amount of distraction or stretch of the urethra and the resultant defect. While the injury grades are descriptive, they do not accurately predict the type of repairs or the number of steps required to repair an injury [19-21].

MANAGEMENT

History and evolution of the repairs — Pelvic fracture urethral distraction defect repair has a long and storied history dating back to the 1950s. One of the earliest techniques in the literature, described by Badenoch, was an unsutured urethral pull-through operation, in which the proximal end of the bulbar urethra was attached to a catheter and pulled into the bladder through the defect and left to heal to the prostatic urethra by scarring [22]. Several scrotal-based procedures brought scrotal skin through the stricture at the first stage, followed by tubularization of the skin into a neourethra at a second stage [23-25].

Other authors described delayed repair techniques that utilized abdominal pubectomy to bridge the gap between the proximal urethra and the prostate [26]. Waterhouse developed a procedure that required removing an entire wedge of the anterior pubis to allow access for the repair [27]. Turner-Warwick described an approach in which the repair was based on the complexity of injury and the type of defect, as well as factors such as the presence of pelvic abscess, fistula, or cavity [28-30]. When necessary, an abdominoperineal approach with a concomitant pubic bone removal was used. Although these techniques were successful, all were associated with significant morbidity and a long convalescence for the patient.

One of the most significant advances in this field was made by George Webster in 1985 and evolved over the subsequent decade [31]. He described a surgical technique that was completely perineal, thus avoiding abdominal exposure, and through a stepwise approach was able to repair very long defects. This stepwise approach provides excellent outcomes with long-term success rates of 97 percent in adults, 91 percent in adolescents, and 97 percent success even for patients undergoing redo urethroplasty [32]. The success of redo repairs holds true in more contemporary series published as well with overall success of redo posterior urethroplasty at 87 percent [33]. Thus, this continues to be our preferred method of repairing these types of injuries. (See 'Our approach' below and 'One-stage perineal anastomotic urethroplasty' below.)

Our approach — Management of posterior urethral injuries from high-velocity projectiles should consist of suprapubic drainage, and a Foley catheter if possible. If there are concomitant injuries to the rectum, a diverting colostomy may be required. Any early attempt at repair is not indicated, since it may cause a significant amount of bleeding, incontinence, and possible erectile dysfunction.

Management of a posterior urethral injury caused by blunt trauma depends upon whether there is any other significant pelvic injury. Immediate suture repair of a posterior urethral injury with evacuation of the pelvic hematoma is indicated in cases where there are concomitant bladder neck injuries, rectal injuries, or other indications for an open laparotomy. In the majority of cases, however, the definitive repair of a urethral injury should be delayed until the patient is stable enough to undergo an elective procedure. The 2023 American Urological Association guidelines for urethral stricture disease state that delayed definitive urethral reconstruction with urethroplasty should be performed rather than delayed endoscopic procedures and that this should only be undertaken after all other major injuries are stabilized when patients can be safely positioned for urethroplasty [16].

While in the past there was significant debate about how best to manage patients with a posterior urethral injury who do not require immediate surgery [34], the American Urologic Association Urotrauma guidelines [15], as well as the updated American Urologic Association urethral stricture guidelines [16], emphasize that most urethral strictures associated with pelvic fractures should be repaired in a delayed fashion with an open posterior urethroplasty [15]. This is also in agreement with the European Urology Association Guidelines on Urological Trauma [35]. As discussed above, these repairs have very high success rates. Furthermore, while allowed by the American Urologic Association urotrauma guidelines [15], primary endoscopic realignment may be performed when not resulting in prolonged attempts but may be associated with a longer convalescence because of the multiple procedures required for recurrent obstruction over an extended timeline [36].

●We prefer early suprapubic drainage with delayed repair in three to six months, rather than primary realignment. This is consistent with the American Urologic Association urotrauma guidelines, American Urological Association urethra Stricture guidelines, the European Association of Urology guidelines on urethral stricture, and the European Association of Urology Trauma guidelines as well [15,16,35,37]. Several reports indicate that strictly waiting three to six months prior to repair may not be necessary and repair can be undertaken sooner as long as the wounds are healed and the perineum is soft [38]. Early drainage/delayed repair decompresses the urinary system in the acute phase to allow convalescence of the patient, and subsequent definitive reconstruction in a controlled setting. From a technical perspective, delayed repair allows the pelvic hematoma to resolve, the prostate to descend, and the urethral defect to shorten. These factors may lower risk of surgical complications when compared with those of early realignment. In a comprehensive review of the pelvic fracture urethral injury literature evaluating outcomes of suprapubic catheter alone, primary open surgical repair, delayed primary open surgical repair, primary open realignment, primary endoscopic realignment, delayed endoscopic treatment, and delayed urethroplasty [39], the authors concluded that delayed urethroplasty offered the best overall outcome with a low rates of recurrence (14.4 percent), erectile dysfunction (12.7 percent), and incontinence (6.8 percent).

●The placement of the suprapubic tube has historically been a concern for increased infection in cases where orthopedic hardware is required for internal fixation of the pelvic fractures. A comprehensive review of the National Trauma Data Bank showed no increased rates of infection in cases of internal fixation with a suprapubic tube in place [40].

●Again, while some surgeons may still prefer primary realignment using endoscopic techniques, with the rationale that early realignment may spare some patients the need for further reconstruction. Long-term follow-up data indicate that the majority of patients develop recurrent strictures after primary realignment that will require further interventions and thereby protract their clinical course. In one retrospective series of 129 patients who underwent endoscopic primary realignment, only 14 percent required no further treatment at a median follow-up of 45 months [41]. The remaining 86 percent developed recurrent strictures at a median of 23 months and required additional definitive procedures (most commonly perineal anastomotic urethroplasty [51 percent] and internal urethrotomy [19 percent]). An earlier meta-analysis with more variable follow-up reported a 49 percent restricture rate among a total of 142 patients treated with primary endoscopic realignment [42]. A multicenter study from the United States prospectively followed 106 patients with pelvic fracture urethral distraction defects [43]. Of the 106 patients, 69 had complete distraction defects requiring suprapubic tube placement. Thirty-seven of these underwent endoscopic realignment and 32 did not. The progression to requiring a urethroplasty was similar in both groups supporting earlier findings that endoscopic realignment does not provide any value in avoiding surgical urethroplasty at a later time.

Suprapubic tube drainage — A suprapubic tube (SPT) can be placed open or percutaneously. Open SPT placement is usually performed in association with surgeries for other traumatic injuries (eg, prostate injury, bladder trauma repair, orthopedic fixation).

A percutaneous SPT is placed when a laparotomy is not required and should only be performed in a patient with a distended bladder. If the patient has a history of prior lower abdominal surgery, a percutaneous SPT should only be attempted with simultaneous cystoscopy and abdominal imaging control to ensure that there is no bowel within the potential tract of the SPT. Percutaneous SPT placement may be performed by an appropriately trained emergency room clinician, general surgeon, urologist, or interventional radiologist.

To place a percutaneous SPT, the patient should be placed supine in a steep Trendelenburg (head-down) position to allow the bowels to fall away from the dome of the bladder. If ultrasound is available, it can be used to guide placement. After injection of a local anesthetic, a puncture incision is made two to three fingerbreadths above the symphysis pubis in the midline. A finder needle can be used to estimate the depth necessary to reach the bladder dome and obtain urine. A trocar or puncture cystotomy tube is then placed into the dome of the bladder at a 45° angle with the tip directed caudally. Once urine is obtained with a trochar or puncture cystotomy tube, the tube should be advanced another 1 to 2 cm to ensure that the tube is adequately within the dome of the bladder. The cystostomy tube is then advanced into the bladder through the trocar, the balloon is inflated with 10 mL of sterile water, and slight traction is applied to the tube to ensure that the dome of the bladder is well apposed to the anterior abdominal wall. The SPT is then secured to the skin with nylon sutures.

Definitive urethral reconstruction — Surgical options for definitive reconstruction of a traumatic posterior urethral injury include repair and realignment. Urethral repair means to close the injury or defect directly with sutures. Urethral realignment means to stent the injury or defect with a catheter without any formal attempt at repair and to allow it to heal by scarring. Both repair and realignment can be performed open or endoscopically (table 4).

Immediate open repair — Immediate open repair involves abdominal or perineal exploration with suture repair of the urethral defect shortly after injury. This treatment option was popular in the past but has fallen out of favor because of high rates of impotence (44 percent), incontinence (20 percent), and stricture recurrence (69 percent) [23,44-46]. These morbidities are often caused by injury to surrounding structures such as the neurovascular bundles during an attempt to mobilize and repair the urethra because of factors such as acute bleeding, poor visualization, and loss of viable tissue planes related to the acute injury [47]. Thus, we have abandoned any attempt at an open repair of urethral injury in the acute period, except in cases where there are concomitant bladder neck injuries, rectal injuries, or other indications for an open laparotomy. (See 'Our approach' above.)

Delayed open repair — Although there is no one "magic bullet" in the definitive treatment of pelvic fracture urethral injuries, the placement of a suprapubic catheter acutely for urinary diversion followed by a delayed repair in three to six months has become the most widely accepted treatment option [31,48-51]. (See 'Our approach' above.)

The three- to six-month delay, during which the patient is managed with suprapubic catheter drainage, permits the orthopedic injuries to stabilize and the patient to undergo rehabilitation in preparation for another reconstructive operation. In the past, urologists were pressured into attempting early urethral realignment to remove the suprapubic catheter because some orthopedic surgeons felt that the presence of a suprapubic catheter may expose the fixation hardware to infection. However, the American Urological Association guidelines on Urotrauma specifically state that surgeons may place suprapubic tubes in patients undergoing open reduction internal fixation for pelvic fracture [15].

An early drainage/delayed repair strategy also allows a general urologist who may have less experience treating pelvic fracture urethral injuries to acutely stabilize the patient by placing a suprapubic tube and defer more complex reconstruction to an experienced trauma urologist after the patient has recovered from the orthopedic or other traumatic injuries.

Preoperative imaging — Before surgery, a combined retrograde urethrogram and antegrade cystography ("up-and-down-o-gram") should be performed to define the length of the distraction defect and any other associated pathology (eg, bladder neck competence, fistula, or bladder calculus). This is in accordance with the 2023 American Urological Association guidelines on urethral stricture, which state that clinicians should use retrograde urethrography with voiding cystourethrogram and/or retrograde and antegrade cystoscopy for preoperative planning of delayed urethroplasty after pelvic fracture urethral injuries [16].

Pelvic MR imaging has been increasingly useful for defining anatomy, specifically estimating the length of the pelvic fracture-associated distraction defect, which helps plan delayed urethroplasty [52]. Researchers from Japan have nicely defined a protocol and the measurements required to estimate the distraction defect length [17]. In our practice, two patients with conventional retrograde and antegrade plain films suggested that the distraction defect was too long to be repaired by any means, but subsequent MR imaging provided more accurate measurement between the proximal urethra, and these patients underwent successful surgical reconstruction.

An active area of investigation involves the use of 3D printed models to help with preoperative evaluation and surgical planning. A group from the Sixth People's Hospital in Shanghai, China reported on a series of three patients undergoing 3D model printing the urethral distraction defect created from preoperative CT scans [53]. While the clinical utility of this planning tool is still under investigation, this may lead to better evaluation and planning for this very complex reconstructive surgery.

One-stage perineal anastomotic urethroplasty — Most pelvic fracture urethral injury defects can be reconstructed with a one-stage perineal anastomotic urethroplasty. This remarkably versatile procedure can overcome long obliterative strictures by allowing the bulbar urethra to take a more direct route to the anastomosis (figure 4). Consequently, only uncommon (<5 percent), extremely complex strictures (eg, bladder base fistula, pelvic floor cavity, urethrorectal fistula) require an abdominoperineal approach or substitution urethroplasty [32,51,54].

The results of a one-stage perineal anastomotic urethroplasty are very good, with a success rate of >90 percent and significant improvement in long-term quality-of-life in experienced centers [55,56]. The rate of de novo erectile dysfunction is low, and if the patient has a competent bladder neck, fewer than 12 percent develop incontinence after repair [57,58]. However, the outcomes are not as good in prepubertal boys, in whom this injury is fortunately uncommon.

Perineal anastomotic urethroplasty involves mobilization of the urethra as a distally based urethral "flap" and transection of the urethra at the point of obliteration. After cutting down onto the tip of a descending sound passed through the suprapubic tube tract into the proximal urethral "stump," the bulbar urethra is anastomosed to the prostatomembranous urethra proximal to the obliteration. The procedure aims to achieve a tension-free bulboprostatic urethral anastomosis using the fewest steps in a stepwise fashion (figure 5) [59]:

●Step 1: Urethral mobilization – Circumferential mobilization of the distal urethra to the suspensory ligament of the penis provides 2 to 3 cm of length, sufficient for anastomosis in 8 percent of our cases.

After a midline perineal incision is created, the bulbar urethra is circumferentially mobilized as proximally as possible. We transect the urethra at this point and then continue to mobilize distally until the suspensory ligament of the penis is reached. This turns the urethra into a flap that is based on retrograde blood flow from the dorsal penile artery and corporal perforating vessels (figure 6). Any previous injury or surgery to the urethra or anastomotic tension could jeopardize the viability of the flap. In those patients, a bulbar artery-sparing posterior urethroplasty may be more suitable [60].

A urethral sound or a flexible cystoscope is then placed through the suprapubic tube tract into the proximal urethra to help identify the proximal urethral stump by palpation. Once the surgeon can locate the proximal stump in the scarred pelvic floor by feel, it can be reached by cutting down upon the urethral sound directly through the pelvic floor. It is imperative to remove all scar tissue in the vicinity of the urethra to create a tension-free mucosa-to-mucosa anastomosis. Once the proximal urethra stump is dissected circumferentially, it is spatulated posteriorly, often as far proximal as the verumontanum. The distal bulbar urethra is spatulated anteriorly. In many cases, this will allow a tension-free anastomosis with radial 4-0 polyglycolic acid sutures. A nasal speculum and sutures that are bent into a J-shape and placed with a "push in-pull out" technique will help in the completion of this sometimes challenging anastomosis (figure 7).

●Step 2: Corporal body separation – Separating the proximal corporal bodies shortens the distance by another 1 to 2 cm and is sufficient for anastomosis in 41 percent of our cases.

When step 1 does not result in a tension-free anastomosis, added length can be gained by routing the urethra between the posteriorly separated corporal bodies. The separation of the corporal bodies may be performed in a bloodless plane for up to 5 cm, which straightens the trajectory of the urethra from the tip of the penis toward the proximal defect.

●Step 3: Inferior wedge pubectomy – An inferior wedge pubectomy can be performed by resecting a 1.5 to 2 cm wide wedge of bone from the inferior surface of the pubis. This further shortens the defect by another 1 to 2 cm, facilitating anastomosis in 28 percent of our cases.

If the first two steps (urethral mobilization, corporal separation) fail to facilitate a tension-free anastomosis, the distance can be further reduced by performing a wedge excision of the inferior pubic arch from the perineum. The corporal separation will expose the interportion of the pubic bone. The dorsal vein will be exposed and ligated, which permits access to excising a small wedge of the pubic bone with an osteotome or a Capener gouge and bone rongeurs. We have found that this step often significantly increases visualization and improves exposure, thus making the anastomosis even easier to perform.

●Step 4: Supracrural rerouting – Rerouting the urethra around the lateral surface of a corporal body provides another 1 to 2 cm of length and is needed in 23 percent of our cases. The urethra is typically routed dorsally around the lateral side of the left corporal body and through the defect created by the inferior pubectomy. This further reduces the distance to the anastomosis by providing an even more direct route from the penis to the proximal urethra. A small tunnel of the bone on the inferior pubic rami lateral to the previously performed midline inferior wedge pubectomy should be removed where the urethra runs to avoid compression between the corporal body and bone.

Other less-used techniques — Other techniques for repair of posterior urethral injury have not withstood the test of time and are associated with complications or other harms that make them less desirable when either immediate or delayed open repair can be accomplished. These techniques involve either immediate or delayed urethral realignment (open or endoscopic). We feel these techniques should be reserved for cases and situations with limited resources and lack of access to specialty centers with experienced trauma and reconstructive surgeons who offer delayed, perineal open repair.

●Immediate open realignment – Open realignment procedure involves open placement of a catheter across the urethral defect to serve as a stent using various techniques (eg, interlocking or magnetic sounds, combined antegrade/retrograde approach) [61]. Immediate open realignment can potentially decrease the length of a distraction defect and thereby reduce the incidence and severity of stricture formation. However, the immediate open approach is associated with bleeding associated with the release of the tamponade effect of any retropubic hematoma. In addition, urethral stricture occurs in at least 50 percent of patients, necessitating additional procedures. While some may argue that a 50 percent stricture rate is a good outcome, we feel that these patients can be better served with delayed open surgical management [45,62].

●Immediate endoscopic realignment – Immediate (within 24 to 72 hours of the injury) endoscopic realignment involves placing a catheter across the urethral defect. This can be accomplished using a variety of techniques, including magnetic guides [63] or interlocking sounds. Immediate endoscopic realignment may be an appropriate treatment if the catheter can be placed across the urethral defect early following the injury and with minimal manipulation. Excessive manipulation with infiltration of irrigant should be avoided, as it may result in worsening of the injury and prolonged convalescence. The American Urological Association guidelines on Urotrauma emphasize that prolonged attempts at primary endoscopic realignment should not be tried in patients with pelvic fracture-associated urethral injury [15].

The reported benefits and harms of immediate endoscopic realignment are inconsistent [36,41,42,64,65]. As an example, the incidence of urethral stricture ranges widely from 50 to 100 percent [31,62]. In addition, endoscopic realignment has the potential for complications such as erectile dysfunction, incontinence, and injuries to other structures such as the rectum.

●Delayed endoscopic realignment – Delayed endoscopic realignment is an option for patients who have stabilized enough and will return to the operating room 5 to 10 days after injury for another reason (eg, orthopedic surgery, wound care intervention). Because the pelvic hematoma tends to be more stabilized and organized, delayed endoscopic alignment has a lower risk of bleeding compared with immediate realignment.

Delayed endoscopic realignment is a simple procedure that can be performed endoscopically by most urologists. The realignment may reduce the severity and length of the stricture, thereby decreasing morbidity of a definitive repair at a later time [66,67]. There is, however, a fairly high rate of stricture recurrence, between 20 and 100 percent, which may necessitate subsequent office endoscopic manipulation or intermittent catheterization [68-71]. In contrast to immediate endoscopic realignment, delayed endoscopic realignment does not seem to increase the incidence of erectile dysfunction.

Delayed endoscopic realignment is typically accomplished by two endoscopists, with the goal of approximating the two distracted urethral ends to facilitate early healing. The antegrade flexible endoscope enters the bladder via the suprapubic catheter tract, negotiates the bladder neck, and emerges in the injury hematoma. The retrograde endoscope (particularly if a 24 Fr resectoscope sheath is used) allows for hematoma irrigation, visualization of the defect, and antegrade passage of a linking guidewire, over which a stenting catheter can be passed across the defect. The catheter is left in place for four to six weeks. Later, a pericatheter retrograde urethrogram will precede stent removal and voiding trial.

When performing any endoscopic manipulation for urethral injuries, one must excise caution not to convert a short urethral distraction defect into a complex stricture. Unnecessary manipulation, excessive irrigation, or heroic attempts at prolonged endoscopic maneuvers may also convert a partial disruption into a complete distraction defect and worsen the injury. Thus, when facing difficulty with any endoscopic intervention, the safest strategy is to simply place a suprapubic tube and defer to a delayed urethral reconstruction at a later time [72].

●Delayed endoscopic repair – Delayed endoscopic repair was used in the past for pelvic fracture urethral distraction defects that were very short after a prolonged period of healing (three to six months after the injury) [73-78]. Although a delayed endoscopic repair may establish urethral continuity, the majority of patients still require subsequent endoscopic manipulation or intermittent catheterization. As such, we no longer recommend delayed endoscopic repair because of a high rate of stricture recurrence and potential injury to surrounding organs such as the rectum [79-82]. The American Urological Association guidelines for male urethral stricture also support delayed urethroplasty rather than delayed endoscopic procedures for the management of pelvic fracture-associated urethral obstruction/obliteration [15].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Genitourinary tract trauma in adults".)

SUMMARY AND RECOMMENDATIONS

●Posterior urethral injury – Posterior urethral injuries usually occur in the setting of significant pelvic fractures, often caused by motor vehicle collisions. The magnitude of injury determines the length of the ultimate defect, ranging from elongation to complete transection of the urethra, with transection seen in most cases. (See 'Introduction' above and 'Epidemiology and Etiology' above.)

●Clinical features and diagnosis – A urethral injury should be suspected in patients with penetrating or blunt trauma to the genitalia or lower abdomen, or a significant pelvic fracture, accompanied by one or more of clinical signs, including blood at meatus, inability to void, perineal hematoma, and high-riding prostate on digital rectal exam. Such patients should undergo a retrograde urethrogram (RUG), which is diagnostic of the urethral injury and establishes the injury grade. (See 'Clinical manifestations' above and 'Diagnostic evaluation' above and 'Diagnosis' above.)

●Approach to management – Posterior urethral injuries from high-velocity projectiles should be managed with suprapubic drainage, and a Foley catheter if possible. If there are concomitant injuries to the distal gastrointestinal tract, a diverting colostomy may be required. Any early attempt at repair is not indicated, since it may cause a significant amount of bleeding, incontinence, and possible erectile dysfunction. (See 'Our approach' above.)

•Immediate open repair – Posterior urethral injuries caused by blunt or crush trauma may require immediate suture repair when there are concomitant bladder neck injuries, rectal injuries, or other indications for an open laparotomy. The immediate open repair should not be performed in any other patients, due to high rates of impotence, incontinence, and stricture recurrence. (See 'Immediate open repair' above.)

•Delayed repair – For patients with a posterior urethral injury caused by blunt trauma who do not require immediate open surgery, surgeons should provide suprapubic drainage followed by delayed repair in three to six months, rather than immediate endoscopic realignment. The delay allows the pelvic hematoma to resolve, the prostate to descend, the urethral defect to shorten, and the patient's other injuries to heal before the reconstructive operation. (See 'Our approach' above.)

●Bladder drainage – Regardless of the surgeon's choice of repair or realignment, they must promptly establish urinary drainage, most commonly with an open or percutaneous suprapubic tube (SPT) (See 'Suprapubic tube drainage' above.)

●Definitive surgical repair – For most patients with a posterior urethral injury due to blunt trauma, the definitive repair should be delayed until the patient is stable enough to undergo an elective procedure. We use a one-stage perineal anastomotic urethroplasty technique that uses one to four steps sequentially, as required by the magnitude of the urethral defect, to accomplish a tension-free bulboprostatic anastomosis. (See 'Delayed open repair' above.)