Reconstruction of Pelvic Fracture Urethral Distraction Defect





Preoperative Management and Planning


Acute Management


A pelvic fracture urethral distraction defect (PFUDD) occurs as a result of significant trauma. Initial management is directed at resuscitation and treatment of concomitant life-threatening injuries. When an injury is suspected clinically, it is confirmed using retrograde urethrography.


Recommended acute management of patients with PFUDD with a complete urethral injury is bladder drainage by insertion of an ultrasound-guided large-bore (16-Fr and above) suprapubic cystostomy catheter. This can be inserted under local anesthesia, or if surgery is necessitated for other injuries, then this catheter can be inserted at the same time. The suprapubic catheter tract should be located as far from any pelvic fracture as possible because bacterial colonization of urine occurs within 48 hours, and intravenous antibiotics are administered to reduce the risk of contamination of a fracture, especially in the case of a pelvic injury requiring internal fixation.


Endoscopic realignment is not recommended in inexperienced hands. For patients who require surgery for other injuries, when appropriate local expertise is available, an attempt can be made at closed endoscopic realignment. Successful endoscopic placement of a catheter for 6 weeks may result in shorter defects in the urethra, although there is no consensus on the role of this technique. In view of the rarity of such injuries, few centers have significant expertise, and there is the risk of inadvertently impairing erectile and sphincteric function. Open realignment of urethral injuries is not recommended because of worsened morbidity.


Subsequent Management


After initial management of concomitant injuries and establishing suprapubic bladder drainage is completed, it is a consensus view that definitive repair should be delayed until at least 3 months after the initial injury to allow resolution of pelvic hematoma.


Patients can therefore be referred to a specialist center with reconstructive urethral surgery expertise for subsequent repair. Preoperative assessment includes a clinical assessment, a synchronous urethrogram and cystogram ( Fig. 95.1 ), and an examination under anesthesia with both urethral and suprapubic endoscopy. Endoscopic examination requires a rigid cystoscope for the distal urethra and a flexible cystoscope (17- to 19-Fr caliber) through the suprapubic tract to assess the bladder and prostatic urethra. This allows evaluation of the bladder neck and assessment of the site of disruption relative to the distal urethral sphincter mechanism (DSM), many of these injuries being distal to the DSM. Except in complicated cases, there is no role for imaging by computed tomography or magnetic resonance imaging. After cystoscopy, a suprapubic catheter of at least 16-Fr should be reinserted, which, after removed for the subsequent repair, allows easy passage of a large sound through the suprapubic tract into the prostatic fossa.




FIGURE 95.1


The use of synchronous antegrade and retrograde urethral contrast studies allows for an accurate assessment of the injury.


After assessment has accurately established the nature of the injury, the majority of cases can be managed via a perineal approach. Except in exceptional circumstances, such as when there are bone fragments entering the urinary tract or disruption of the bladder neck, perineoabdominal surgery is not necessary. In those with hip or leg fractures, the positioning of the patient in the lithotomy position is also considered in planning surgery.


The patient is consented for urethral repair via a perineal approach and warned of the specific risks of erectile dysfunction, incontinence, and recurrence of stricture.




Patient Positioning and Surgical Incision


Definitive Repair of Pelvic Fracture Urethral Distraction Defect


The patient has a preoperative urine specimen taken for culture and sensitivity. At induction of anesthesia, broad-spectrum antibiotics are administered.


Positioning


The patient is placed in the lithotomy position. Exaggerated lithotomy with lambda and other incisions are not necessary because a single midline incision suffices. The suprapubic catheter is removed, and the abdomen and perineal skin are prepared.


An 18- to 20-Fr Clutton urethral sound is place into the suprapubic catheter tract and by palpation into the bladder neck and prostatic fossa.


Equipment


A Turner Warwick ring retractor with six rake blades allows good exposure of the urethra ( Fig. 95.2 ). An additional self-retaining retractor (e.g., Travers) is useful when the corpora are split to aid access. (Depending on surgical preference, other retractors may be favored.)




FIGURE 95.2


( A ) Turner Warwick retractor and metal blades are very effective at retracting the periurethral tissues. ( B ) The use of the knobs on the retractor, allowing the retraction of sutures.

(Adapted from Mundy AR. Current operative surgery: urology. London: Bailliere Tindall; 1988.)


A fine metal suction with a terminal fenestration hole is useful for identifying bleeding in the infrapubic pelvic cavity and may be used to stabilize and retrieve sutures from the inner lumen of the urethra. A Turner Warwick needle holder has an offset, curved handle and allows visualization of a mounted needle when placing sutures in the limited space of the pelvic cavity.


An ear, nose, and throat (ENT) speculum is useful for placement in the lumen of the urethra when performing urethral suture placement. A hammer and chisel together and bone rongeurs are required when performing an inferior pubectomy. Bleeding from the pubic bone may require bone wax for control.




Operative Technique


Step 1: Incision and Dissection of the Distal Urethra


A midline perineal incision is performed (≈10 cm long) and deepened through the subcutaneous fat. The bulbospongiosus muscles are identified and dissected from the bulbar urethra. A Turner Warwick retractor with six rake blades is used to retract the subcutaneous tissues and bulbospongiosus muscles, which are held by stay sutures. A sound is passed into the distal urethra, which is sharply dissected, identifying the blind ending. The urethra is dissected from the underlying corpora up to the penoscrotal junction and transected at the site of disruption from the proximal scar tissue, which is then removed ( Fig. 95.3 ). A stay suture in the urethra helps in retraction once mobilized. The urethra is spatulated dorsally for approximately 1.5 cm to allow passage of a 32-Fr sound. It is then rotated through 180 degrees before reanastomosis to allow the spatulation where the spongiosum is easiest to anastomose ( Fig. 95.4 ).




FIGURE 95.3


Mobilization of distal urethra and excision of fibrosis to identify the tip of the sound passed via the suprapubic tract.



FIGURE 95.4


Spatulation of the urethra to facilitate fashioning of a wide anastomosis.

(Adapted from Mundy AR. Current operative surgery: urology. London: Bailliere Tindall; 1988.)


A combined abdominal and perineal approach is rarely necessary, as noted earlier. When the proximal urethra is difficult to access because of significantly displacement, an abdominal incision and mobilization of the bladder and prostate from the bony surface of the pubic symphysis together with excision of the pubic symphysis has been described. The authors have rarely had to use this approach and have not had to perform total excision of the pubic symphysis.


In total PFUDD injuries, the proximal urethra is separated from the distal portion by scar tissue from the organized hematoma subsequent to the urethral disruption. Several centimeters of scarred tissue may need excision. Insertion of a sound via the suprapubic tract into the prostatic fossa and urethra allows the proximal defect to be identified by feel, with subsequent incision on to the sound ( Fig. 95.5 ). Alternatively, a flexible cystoscope can be passed suprapubically, and identification of the transillumination from the cystoscope can aid dissection. Occasionally, digital examination of the rectum may be helpful for orientation


Jan 2, 2020 | Posted by in UROLOGY | Comments Off on Reconstruction of Pelvic Fracture Urethral Distraction Defect

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