Avoiding and managing lower urinary tract injuries during pelvic surgery





Introduction


Lower urinary tract injury is one of the most serious complications of gynecologic surgery and, in addition to causing significant patient morbidity, is a common cause of litigation. Between 50% and 90% of all lower urinary tract injuries occur during gynecologic surgery because of the intimate anatomic relationship that exists between the female genital and lower urinary tracts.


Review of the surgical literature reveals two disturbing facts: most injuries occur during gynecologic surgery performed for benign and otherwise uncomplicated conditions, and most lower urinary tract injuries are not recognized during the operative procedure in which they occur. For these reasons, we emphasize prevention and recognition of lower urinary tract injuries during gynecologic surgery.


Incidence


Historically, the reported rates for injuries during pelvic surgery range from 0.2% to 1.8% for bladder injury and from 0.03% to 1.5% for ureteral injury. The true figures are thought to exceed these numbers, given the number of unreported cases, the spontaneous resolution of partial ureteral obstructions, and the loss of some renal systems. When universal cystoscopy was performed in a large cohort of women undergoing hysterectomy for benign disease, the rate of bladder injury was 2.9%, and the rate of ureteral injury was 1.8%, with a cumulative injury rate of 4.3% ( ). As 600,000 hysterectomies are performed annually in the United States, an estimated 25,800 women could experience a bladder or ureter injury each year in this country as a result of this procedure. Laparoscopic and vaginal hysterectomy have been associated with higher rates of bladder injury in the United States than abdominal hysterectomy. Ureteral injury is also more commonly observed after laparoscopic (and robotic) hysterectomy. High-volume surgeons have demonstrated lower rates of urinary tract injury regardless of mode of hysterectomy than low-volume surgeons.


Surgery for prolapse or incontinence increases the risk of urinary tract injury. Vaginal surgery for anterior and/or apical pelvic organ prolapse is associated with an intraoperative ureteral obstruction rate of approximately 5%; most of these injuries are sustained during high uterosacral ligament suspension, proximal McCall culdoplasty, and colpocleisis. Anterior colporrhaphy is associated with a 0.5% to 2% risk of ureteral obstruction, prompting consideration for routine cystoscopy after this procedure as well. Retropubic slings result in a 3% to 5% rate of bladder perforation when performed by experienced surgeons but can occur in up to 34% of cases performed by resident trainees, whereas transobturator slings result in bladder perforation in less than 1% of cases. If these injuries are recognized during surgery, no long-term sequelae are sustained.


Studies of genitourinary fistulas reveal that the ratio of bladder injury to ureteral injury resulting in fistula is approximately 5:1. Most injuries that result in the formation of genitourinary fistulas are not recognized during surgery.


Prevention of injuries


In over 40% of all ureteric injuries, no predisposing factors are identified, and the surgery that is performed is described as routine. Familiarity with the course of the ureter, and maintaining ureteric consciousness during each gynecologic procedure, are critical. Contributing factors that have been identified in ureteral injuries include bleeding, enlarged uterus, endometriosis, adhesions, obesity, and pelvic organ prolapse. An awareness of these risk factors, and an attempt to optimize surgical planning and execution, are paramount. The liberal use of cystoscopy after the injection of indigo carmine or similar dye is strongly endorsed.


Preoperative assessment


The patient’s history, physical examination, and preoperative laboratory evaluation may suggest abnormal function of the urinary tract. Ureteral kinking and obstruction should be considered in women who present with massive prolapse. Sonographic imaging of the urinary tract is useful in determining kidney size, detecting ureteral obstruction, and estimating urinary residual volumes. A computed tomography (CT) urogram documents anatomic abnormalities, further defines renal function, and localizes ureteric obstruction; it is important in the evaluation of complex genitourinary fistulas. A retrograde pyelogram may be useful intraoperatively to determine the site of ureteral obstruction. Routine preoperative imaging studies have not been shown to reduce the incidence of operative injuries to the lower urinary tract.


Cystourethroscopy is indicated in the preoperative evaluation of hematuria, abnormal urine cytology, persistent or recurrent urinary tract infections, lower urinary tract fistulas, urethral or bladder diverticula, urethral and bladder pain, selected cases of urinary incontinence, certain vaginal mesh and sling complications, and staging of gynecologic malignancies.


Preoperative retrograde ureteral stent or catheter placement has not been shown to reduce the incidence of surgical injury to the ureter. The procedure itself may cause bleeding, edema, and perforation of the ureter. The stent is often difficult to feel within an area of fibrosis, and it may predispose the ureter to damage as a result of the immobility that it imparts to the ureter.


Intraoperative care


The pelvic surgeon should always be ureter-conscious. Full knowledge of the anatomic location and course of the ureters is paramount to injury prevention. Visualization of ureteric peristalsis may not be adequate evidence of ureteral patency. One can always find the ureter on the medial leaf of the broad ligament after opening the roof of the pararectal space and dissecting medial to the iliac vessels.


The most common location of ureteral injury during hysterectomy is in the distal 3 to 4 cm of the ureter where the ureter crosses under the uterine artery in the cardinal ligament, and then across the lateral vaginal fornix to enter into the bladder. Potential sources of ureteric injury are demonstrated in Fig. 24.1 . One must recognize that the close anatomic relationship between the uterine artery and ureter in the cardinal ligament puts the ureter at risk during each hysterectomy, but it is especially vulnerable to lateral thermal spread when electrocautery is used for vessel ligation. Familiarity with the specific properties of the vessel-sealing instrument that is selected may assist with injury prevention. The ureters may also be kinked during obliteration of the cul-de-sac, plication of the uterosacral ligaments, or suspension of the vaginal apex.




Fig. 24.1


Course of the ureter. Locations of potential sources of ureteral injury during gynecologic surgery are noted ( dotted circles ).

(From Walters MD, Barber MD. Hysterectomy for Benign Disease (with CD) . Philadelphia: Elsevier Inc.; 2010.)


In the operating room there are no substitutes for appropriate case selection, good lighting, proper patient preparation and positioning, adequate exposure, and strict adherence to sterile techniques. Lighting can be improved by the use of headlamps, light-containing suction irrigators, or fiberoptic lighted retractors. During complicated cases, abdominal–perineal–vaginal preparation, drapes that permit access to the abdominal and vaginal areas, positioning of the patient in universal stirrups, and a transurethral three-way continuous irrigation balloon catheter (16 or 18 French) for emptying and filling the bladder are recommended. These measures give the surgeon the flexibility to operate abdominally or vaginally, to perform endoscopy, and to detect and repair lower urinary tract injuries if they occur.


During all surgical procedures, sharp dissection is preferable to blunt dissection, and taking small pedicles is preferred to taking large pedicles. When hemostasis is a problem, pressure should be applied with a sponge stick until the bleeding vessel can be identified and selectively clamped. Many ureters are damaged by the application of clamps in a frantic effort to control pelvic hemorrhage.


Abdominal approach


Abdominal incisions should allow adequate exposure of the entire pelvis. Entry into the peritoneal cavity should be as cephalad as possible to avoid direct cystotomy. The surgeon should be aware that the bladder may be pulled up beneath the anterior abdominal wall by its peritoneal reflection as a result of incomplete emptying, tumor, or previous surgery, especially cesarean section. If a cystotomy is sustained in the extraperitoneal portion of the bladder, single-layer closure without prolonged catheter drainage is adequate.


Entry into the peritoneal cavity is followed by exploration of its contents, restoration of normal anatomic relationships, and exposure of the operative site. Attention is given to the location and size of each kidney. With the patient in the Trendelenburg position, the bowel may be packed into the upper abdomen and retained by a retractor.


At this point, an effort should be made to identify both ureters and to trace their pelvic courses. The ureters are most easily identified as they descend into the pelvis over the bifurcation of the common iliac arteries. They then follow the posterior boundaries of the ovarian fossae to pass beneath the uterine arteries and to course anteriorly and laterally about the cervix and upper vagina. Each ureter enters a separate tunnel within the base of the bladder. Although palpation of the ureter between the forefinger and thumb imparts a “clicking” sensation and sound, these characteristics can also be obtained by palpating other retroperitoneal structures. To positively identify the ureter, it is best to observe its distinctive periodic peristalsis directly.


The ureter usually can be dissected away from or out of a gynecologic disease process. The aim is to do so with the least possible ureteral trauma. Placing the tips of a right-angle or tonsil forceps between the adventitial sheath of the ureter and the adjacent tissue to guide the dissection is helpful. If at all possible, the ureter should not be separated from its overlying peritoneum. This attachment protects the ureter’s blood supply, elevates it out of the depths of the pelvis (where it might be surrounded by blood and serum), and assists its peristalsis. If a portion of the ureter is invaded by endometriosis or cancer, it may have to be resected and a ureteroneocystostomy or ureteroureterostomy performed.


Likewise, determining the location and extent of the outer wall of the bladder is important. Sharply dissecting the bladder from adjacent pathologic conditions is usually possible. Rarely, in some cases of endometriosis or cancer, resecting a portion of the bladder wall is necessary. The presence of hematuria may indicate that a full- or partial-thickness bladder injury has been sustained and demands further investigation.


Increasingly, urogynecologists and reconstructive pelvic surgeons are encountering dense adherence of the bladder to the posterior symphysis when performing repeat retropubic procedures, or to the lower uterine segment in cases of prior cesarean section. Sharp dissection of the bladder from the lower uterine segment is always recommended ( Fig. 24.2 ). When dense adhesions are encountered, perform an extraperitoneal cystotomy in the dome of the bladder, then dissect the bladder and upper urethra from the surrounding tissues under direct vision. Experience has shown that this procedure reduces the extent of damage to both organs.




Fig. 24.2


Sharp dissection of the bladder flap reduces the risk of bladder injury.

(Modified from Lee RA, Hagen JV. Atlas of Gynecologic Surgery . Philadelphia: WB Saunders; 1992. Copyrighted by and used with the permission of Mayo Foundation for Medical Education.)


Vaginal approach


In preparing the patient for vaginal surgery, we drain the bladder with a transurethral catheter, and then we sometimes instill undiluted indigo carmine (5 mL) into the bladder. After this is done, the catheter is clamped or removed to keep the dye within the bladder. During surgery, if the bladder is partially or completely incised, the blue color of the indigo carmine is recognized, alerting the surgeon to the bladder injury. If this step has been omitted, and fluid is encountered during dissection, the bladder can be retrograde-filled with either saline mixed with methylene blue or indigo carmine, and one can look for extravasation of dye. This likely is more helpful than cystoscopy.


During vaginal operations, the surgeon should avoid a cystotomy by identifying the trigone and base of the bladder. Unlike an extraperitoneal cystotomy that can occur during entry into the abdominal cavity during laparotomy, a cystotomy that is sustained during attempted entry into the anterior cul-de-sac during vaginal hysterectomy is in the supratrigonal, intraperitoneal portion of the bladder and carries an increased risk for fistula formation if not repaired correctly ( Fig. 24.3 ). Helpful tips for correct bladder identification include palpating the balloon of a transurethral catheter, inserting a probe or Kelly clamp and palpating its tip, or reaching through a posterior colpotomy incision around and in front of the lower uterine segment with a finger or curved retractor and seeing the tip between the bladder and the lower uterine segment. If one can successfully accomplish entry into the anterior cul-de-sac and place a vaginal retractor to deviate the bladder and ureters out of the surgical field before clamping the cardinal ligaments, the risk of ureteral injury is minimized ( Fig. 24.4 ). If a cystotomy is sustained during attempted entry into the anterior cul-de-sac, the edges should be tagged with sutures, and the cystotomy used as a guide for the correct dissection plane. The cystotomy should be closed after completing the hysterectomy.




Fig. 24.3


Most cystotomies that occur during vaginal hysterectomy are in the supratrigonal, transperitoneal portion of the bladder and carry an increased risk for fistula formation if not repaired correctly.



Fig. 24.4


Ureter anatomy in relation to the uterus at total vaginal hysterectomy. Upward traction of the bladder during vaginal hysterectomy increases the distance of the ureter away from the area of clamp placement.

(From Walters MD, Barber MD. Hysterectomy for Benign Disease (with CD) . Philadelphia: Elsevier Inc.; 2010.)


During vaginal surgery, visualization of the ureter is difficult and somewhat hazardous. When the pelvic cavity has been opened, it is possible, with experience, to palpate the ureters against an appropriately placed vaginal sidewall retractor. This is a very important maneuver when operating on patients with prolapse and when performing extensive culdoplasties. If there is any question about the integrity of the ureters or bladder, cystoscopy should be performed.


Dissection of the anterior vaginal wall exposes the urethra and the bladder trigone to injury. Most urethral injuries result from diverticulum repair, anterior colporrhaphy, urethropexy, or instrumentation of the urethra. Increasingly, urethral injuries are caused by midurethral sling procedures, either during the initial dissection or following trocar placement. Urethral injuries, both direct and indirect, may damage the organ’s sphincter mechanism and cause stress urinary incontinence.


Removal of vaginal mesh may result in bladder and unrecognized ureteral injury. Based on reports of severe delayed morbidity from unilateral and bilateral ureteral injury following vaginal mesh removal, routine performance of cystoscopy with these procedures is recommended.


Laparoscopic approach


Increasing numbers of urinary tract injuries have been reported since the introduction of laparoscopic surgery. In a study where intraoperative cystoscopy following the injection of indigo carmine was routinely performed after total laparoscopic hysterectomy, the incidence of injury was 4%. Laparoscopically-assisted vaginal hysterectomy has demonstrated consistently higher rates of lower urinary tract injury than either abdominal or vaginal hysterectomy. The incidence of urinary tract complications appears to increase with the complexity of the procedure, likely because of adhesions caused by endometriosis, pelvic inflammatory disease, or previous surgery. Alternatively, ureteral injuries may be increased because of instrumentation that is used for vessel sealing, or because ureteral identification is more challenging when the ureter cannot be directly palpated.


Most bladder injuries result from sharp dissection, with or without cautery, during laparoscopically-assisted vaginal hysterectomy. Many surgeons believe that the incidence of bladder injuries associated with laparoscopically-assisted vaginal hysterectomy can be reduced if the bladder dissection is done vaginally instead of laparoscopically. Most series of laparoscopic urinary continence and pelvic support procedures report some bladder and urethral injuries. The incidence of these injuries appears to be related directly to the surgeon’s experience with these procedures.


Comparative studies of laparoscopic versus robotic-assisted hysterectomy are currently not large enough to delineate any difference in urinary tract injury. The absence of haptic feedback with robotic surgery could potentially increase the risk of injury. Rates of bladder injury during robotic sacrocolpopexy, however, have not been higher than during laparoscopic or open sacrocolpopexy. Anecdotal reports of extensive bladder and ureteral injury with complex vesicovaginal fistulae following robotic-assisted hysterectomy exist.


A surgical technique that may reduce the risk of ureteral injury during any type of laparoscopic hysterectomy is the use of a uterine manipulator with either a cervical ring or cup that fits tightly into the vaginal fornices. Upward traction on the ring during uterine artery ligation and colpotomy places the ureters more lateral and decreases the risk of lateral thermal spread and ureteral injury.


During laparoscopy, urinary tract injury may be revealed by direct observation, injection of dye solution, presence of gas in the catheter bag, and detection of bubbles during cystoscopy. If urinary tract injury is suspected, cystoscopy should be performed and sometimes repeated. If ureteral injury is suspected, a ureteral catheter should be inserted.


Recognition and management of injuries


Several general principles apply to the management and repair of all lower urinary tract injuries. The administration of prophylactic antibiotics is indicated. The extent of the damage to the urinary tract must be explored. Devitalized tissues must be excised. Urinary tract repairs should be performed with small-caliber delayed absorbable (polyglactin or polyglycolic acid) or absorbable (chromic) suture. Absolutely no tension should be placed on the repair site. Extraperitoneal suction drainage should be placed adjacent to, but not in contact with, all retroperitoneal repairs. Bladder drainage is important to reduce tension within the wall of the bladder during the healing phase.


Recognition of ureteral injury


All pelvic surgeons should have a clear algorithm for the recognition and management of ureteral injury. Although the use of intraoperative cystoscopy does not usually prevent urinary tract injury, it does allow for the early diagnosis and repair of injuries and avoids the need for additional surgery and/or the potential loss of renal function. Box 24.1 describes the recommended sequence of steps, which are described in detail later.



Box 24.1

Steps to Help Recognize Ureteral Injury During Gynecologic Surgery




  • 1.

    Request the injection of indigo carmine dye at least 10 minutes before the anticipated start of cystoscopy to maximize surgical efficiency.


  • 2.

    If >10 min and no flow of blue urine, give 10 mg furosemide IV, unless medically contraindicated.


  • 3.

    In cases of uterosacral ligament suspension, high McCall culdoplasty, and anterior repair, perform cystoscopy after each step to facilitate the correct identification of any obstructing sutures. If efflux is not observed, release offending sutures (in case of uterosacral ligament suspension, release distal stitch first) and repeat cystoscopy.


  • 4.

    If still no urine flow, attempt to pass a ureteral catheter—if successful, leave in place for 4 to 6 weeks to prevent postoperative ureteral stenosis.


  • 5.

    Perform retrograde pyelogram to identify location of ureteral injury.


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Nov 27, 2021 | Posted by in GYNECOLOGY | Comments Off on Avoiding and managing lower urinary tract injuries during pelvic surgery
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