This article provides an overview of the open surgical management of posterior urethral disruption injuries. The discussion includes the evaluation of the patient before surgery with a focus on urethral imaging and details of posterior urethroplasty surgical technique.
Key points
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After suprapubic tube placement, delayed open urethral reconstruction with excision and primary anastomosis via a perineal approach is the standard of care for the initial treatment of pelvic fracture urethral disruption injuries and treatment after failed endoscopic realignment.
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Before urethroplasty, accurate assessment of the defect is reliably obtained with a retrograde urethrogram and simultaneous antegrade cystourethrogram with contrast instillation through the tip of the scope positioned in the prostatic urethra.
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Vascular testing before urethral reconstruction may identify patients who are at risk for ischemic anterior urethral stenosis and who may benefit from penile revascularization before posterior urethroplasty.
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When performed using the proper technique, posterior urethroplasty offers a high success rate and a low complication rate.
Introduction: nature of the problem
Pelvic fracture trauma in males, often secondary to motor vehicle trauma or pelvic crush injuries, can be associated with injuries to the posterior urethra, especially where there is pubic symphysis diastasis or there are displaced inferomedial pubic bone fractures. When the pelvis is fractured, the patient is often found to have blood at the urethral meatus. Additional symptoms and signs of urethral injury include bladder distension, inability to void, perineal hematoma, and possibly a high riding prostate on digital rectal examination.
A retrograde urethrogram (RUG) is indicated when a urethral injury is suspected and typically shows extravasation as a result of a partial tear, or more often, a complete disruption. The term prostatomembranous disruption is often used to describe these injuries, and this terminology suggests that the transection occurs at the junction of the prostatic and membranous portions of the posterior urethra. However, more recent studies, including an autopsy review of male patients who sustained pelvic fracture–related urethral injuries and died of associated multiple trauma, revealed that the injuries are generally bulbomembranous and distal to the urogenital diaphragm. There can be proximal or distal extension, but the injury generally remains distal to the verumontanum of the prostate. Continence after repair is maintained primarily by the proximal bladder neck. However, in many patients, there is also a significant rhabdosphincter contribution, as shown by video urodynamic testing after reconstruction.
The standard management approach is suprapubic tube placement and delayed posterior urethral reconstruction. Alternatively, primary realignment can be performed, which is discussed by Wessels and colleagues, elsewhere in this issue. Should this option fail, the definitive treatment is then delayed posterior urethroplasty with excision and primary anastomosis via a perineal approach.
Introduction: nature of the problem
Pelvic fracture trauma in males, often secondary to motor vehicle trauma or pelvic crush injuries, can be associated with injuries to the posterior urethra, especially where there is pubic symphysis diastasis or there are displaced inferomedial pubic bone fractures. When the pelvis is fractured, the patient is often found to have blood at the urethral meatus. Additional symptoms and signs of urethral injury include bladder distension, inability to void, perineal hematoma, and possibly a high riding prostate on digital rectal examination.
A retrograde urethrogram (RUG) is indicated when a urethral injury is suspected and typically shows extravasation as a result of a partial tear, or more often, a complete disruption. The term prostatomembranous disruption is often used to describe these injuries, and this terminology suggests that the transection occurs at the junction of the prostatic and membranous portions of the posterior urethra. However, more recent studies, including an autopsy review of male patients who sustained pelvic fracture–related urethral injuries and died of associated multiple trauma, revealed that the injuries are generally bulbomembranous and distal to the urogenital diaphragm. There can be proximal or distal extension, but the injury generally remains distal to the verumontanum of the prostate. Continence after repair is maintained primarily by the proximal bladder neck. However, in many patients, there is also a significant rhabdosphincter contribution, as shown by video urodynamic testing after reconstruction.
The standard management approach is suprapubic tube placement and delayed posterior urethral reconstruction. Alternatively, primary realignment can be performed, which is discussed by Wessels and colleagues, elsewhere in this issue. Should this option fail, the definitive treatment is then delayed posterior urethroplasty with excision and primary anastomosis via a perineal approach.
Surgical technique: preoperative planning
3-Month Delay
We wait 3 months from the time of injury or catheter removal in cases of failed primary realignment before performing urethroplasty, to allow time for the initial extravasation to heal, hematoma to resolve, and the extent of the injury to become clearly defined. It has been shown that after manipulation, several months of urethral rest is required for before anterior urethral strictures become clearly defined. When there is a pelvic fracture–associated injury to the posterior urethra, initial imaging reveals extravasation, whereas imaging 3 months after injury typically confirms no extravasation and clear delineation of the location and length of the defect. Recent publications indicate that the delay is often a minimum of 3 to 6 months. However, the interval between initial injury and urethroplasty can exceed 1 year when there are associated injuries. A recently presented abstract indicated that urethral reconstruction less than 6 weeks after the injury may be associated with results similar to when there is a delay of 3 or more months. However, there are no recent publications suggesting that a delay of less than 3 months is appropriate, and the current delay of no less than 3 months is the current published minimum period of urethral rest.
Suprapubic Urinary Diversion
Suprapubic tube urinary diversion always precedes urethroplasty. The ideal suprapubic tube is no less than 16 French, midline, and 2 fingerbreadths above the pubic symphysis. However, patients are often initially managed with tubes that are far lateral to the midline or just above the symphysis. In some cases, very small caliber pigtail catheters are placed ( Fig. 1 ). When patients are referred for posterior urethral reconstruction, and have tubes of inadequate caliber or if the tube is not in the ideal position, it is our preference to percutaneously place a new 16-Fr tube. This procedure is generally performed as soon as possible when the caliber is small, and no less than 1 month before urethroplasty so there will be an established stable tract at the time of surgery. Small caliber pigtail catheters are especially prone to encrustation and urinary retention. Moreover, catheters placed just above the symphysis are more uncomfortable than catheters placed in a higher position away from the bone. The main benefit of having the suprapubic tube midline well above the symphysis with an established tract is that this facilitates the surgery and prevents the need for a temporary vesicostomy. During posterior urethroplasty with the patient in the lithotomy position, after perineal exposure is achieved and the urethra is transected, a metal sound is generally advanced through the established tract, and perineal dissection proceeds toward the tip of the sound until the sound can be seen and advanced into the perineum. When the caliber of the tract is inadequate, sounds do not advance without dilation at the time of the surgery. This situation can be associated with bleeding and compromise of the tract. When the tube is just above the bone, a very acute angle is needed to advance the sound through the bladder neck. Moreover, when the tract is lateral to the midline, the rigid sound cannot be reliably advanced medially toward the midline bladder neck and then distally along the posterior urethra. One option is to create a temporary vesicostomy. However, this procedure adds considerable time and morbidity to the reconstructive surgery and therefore this is not our preference.
Preoperative urethral evaluation: cystoscopy
Before definitive urethral reconstruction, urethroscopy, antegrade cystoscopy, and a simultaneous antegrade cystourethrogram and RUG together provide a definitive diagnosis of the length and location of the defect. One common imaging technique is for the bladder to be filled with contrast by gravity through the suprapubic tube and for an RUG to be performed as the patient is asked to perform the Valsalva maneuver and attempt to void. As the patient attempts to void, if the bladder neck opens, there is filling of the posterior urethra proximal to the obliteration, and the length of the defect is determined ( Fig. 2 A). However, in many cases, the patient cannot relax to void when the urethra is obliterated and contrast is being injected through the penis. When the bladder neck is intact, the appearance is as shown in Fig. 2 B. The distance between the bladder and the distal end of the defect is not the length of the distraction defect, because the prostatic urethra is not visualized. In a recent study in which the goal was to determine if the type of urethroplasty could be predicted based on certain features from the preoperative imaging, 38% of the 100 study patients evaluated with a Valsalva cystourethrogram and RUG were excluded because there was no visualization of the urethra below the bladder neck.
Our preferred approach is to first perform antegrade cystoscopy with the patient prepared and draped in the oblique position after a 35 × 43 cm (14 × 17 inch) scout film is obtained to confirm proper position and penetration. Some patients develop bladder calculi, and when identified, the stones can be removed before urethroplasty. The bladder neck is then inspected for coaptation. An open bladder neck at rest suggests that there may be an increased incidence of incontinence after urethral reconstruction. Iselin and Webster identified 15 patients who sustained pelvic fracture urethral injuries and had an open bladder neck at rest. Six were continent and 8 were incontinent after urethroplasty. However, MacDiarmid and colleagues identified 4 patients who had an open bladder neck at rest, and all of these patients were continent after surgery. Although some surgeons occasionally perform bladder neck reconstruction at the time of posterior urethroplasty, most reconstructive urologists do not perform simultaneous bladder neck surgery, given the observation that an open bladder neck at rest does not reliably predict postoperative incontinence. When we observe an open bladder neck at rest, the patient is counseled that there may be an increased incidence of postoperative incontinence, but this finding does not influence our management.
Preoperative urethral evaluation: urethral imaging
Once the scope is advanced through the bladder neck, the location of the proximal aspect of the injury is noted, and this is almost always distal to the verumontanum of the prostate within the membranous urethra. With the tip of the scope at the level of the obliteration, full-strength contrast is injected, which then back fills the posterior urethra and bladder. Simultaneously, an RUG is performed. Our preferred technique for performing an RUG is to place a gauze around the coronal sulcus to place the penis on stretch, and inject contract through a cone-shaped Taylor adaptor (Cook Urological Incorporated, Spencer, IN, USA) connected to a 60-mL syringe filled with full-strength contrast ( Fig. 3 ). Many published textbooks advocate the advancement of a catheter into the fossa navicularis and inflation of the balloon with 1 to 3 mL of contrast for form a seal. However, the balloon caliber of catheters of several different sizes when inflated with only 2 mL of fluid or air is approximately 59 French, and the normal caliber of the adult anterior urethra is approximately 30 French, except at the level of the urethral meatus and fossa navicularis, where the caliber is approximately 24 French ( Fig. 4 A). Therefore, the balloon dilates the normal distal anterior urethra, which can be associated with considerable pain and even stricture disease of the fossa navicularis. We have seen patients referred for strictures initially limited to the bulbar urethra who then developed narrow caliber fossa strictures after undergoing painful urethral imaging when the technique included balloon inflation within the fossa navicularis (see Fig. 4 B).
Simultaneous antegrade and retrograde imaging and endoscopy performed with proper technique clearly defines the length and location of the defect. Other imaging modalities that can be used include magnetic resonance imaging and ultrasonography. However, we have never found an indication to perform these additional tests. Fluoroscopy offers the advantage of dynamic real-time imaging. However, disadvantages include a reduced field of view and decreased resolution compared with conventional radiographs. We prefer flat plate imaging using digital cassettes that can be digitized and stored electronically and also printed on 14 × 17 film. Although magnification and positioning can influence the scale, we have observed that the length of the obliteration measured directly on the film accurately corresponds to the length of the defect at the time of surgery. Most defects are 1 to 3 cm in length and within the membranous urethra, with possible extension into the most proximal bulbar urethra. Although pelvic fracture trauma typically injures the posterior urethra, if there is also straddle trauma at the time of the pelvic fracture, the injury can be to the bulbar urethra. The specific location of the injury can influence the management. For example, a man who sustained pelvic fracture trauma during a race car accident was found to have significant extravasation on an RUG on the day of the injury and was managed with a laterally placed suprapubic tube. Delayed imaging and antegrade cystoscopy confirmed a proximal bulbar urethral defect and a normal membranous urethra ( Fig. 5 ). Although both traumatic proximal bulbar and membranous disruptions are managed with excision and primary anastomosis, bulbar urethroplasty does not require antegrade access to facilitate identification of the patent proximal segment. If the injury were membranous, then a new midline suprapubic tube would have been placed to facilitate subsequent antegrade access to the proximal segment at the time of posterior urethroplasty. However, because antegrade access is not required for bulbar urethroplasty, the placement of a new midline tube was not required.
