INTRODUCTION — The reproductive and urinary tracts in women are closely related anatomically and embryologically. Knowledge of this anatomy plays an important role in the prevention of urinary tract injury during gynecologic surgery. The primary approach to prevention is careful surgical dissection and knowledge of the position of urinary tract structures within the surgical field.

The prevention of urinary tract injury in gynecologic surgery, primarily hysterectomy, will be reviewed here. The evaluation and management of urinary tract injury in gynecologic surgery, urinary tract injuries during advanced procedures performed for urinary incontinence, pelvic organ prolapse, or gynecologic malignancy, as well as during obstetric procedures are discussed separately. (See "Urinary tract injury in gynecologic surgery: Identification and management" and "Radical hysterectomy" and "Cesarean birth: Surgical technique and wound care" and "Operative vaginal delivery".)

INCIDENCE — The overall rate of urinary tract injury associated with pelvic surgery in women ranges from 0.3 to nearly 1 percent [1-3]. Bladder injury is approximately three times more common than ureteral injury [1,4]. Up to 2.4 percent of patients may require concomitant urologic intervention after hysterectomy-related injury to the urinary tract [5].

URINARY TRACT INJURY

Epidemiology — Ureteric injuries at the time of hysterectomy, both recognized and unrecognized, are a significant cause of morbidity and mortality. In a study of a large health care database including over 223,000 patients, 81 percent of whom underwent hysterectomy for benign indications, ureteral injury occurred in less than 1 percent of patients (0.78 percent) and was unrecognized in 62 percent of cases [3]. While both recognized and unrecognized ureteral injury increased the risk of serious postoperative complications, the effect was more pronounced with unrecognized injury. Compared with no documented ureteral injury, recognized and unrecognized injury increased the adjusted odds ratios of 90-day hospital readmission (1.5 and 24.2, respectively), sepsis (2.0 and 11.9, respectively), nephrostomy tube placement (66.0 and 1792, respectively), and urinary tract fistula (5.9 and 124, respectively). While there was no significantly increased risk of acute renal failure or death for recognized ureteral injuries compared with no injuries, unrecognized injury was associated with a nearly 24-fold increased risk of acute renal failure and 40 percent increased odds for death.

Although the incidence is so low that a particular surgeon may only experience none to a few cases of urinary tract injury in their career, because of the number of hysterectomies being performed worldwide and the aggregate morbidity and mortality, it is a compelling argument that all surgeons need to do more to prevent injury.

Role of cystoscopy — Cystoscopy (full terminology cystourethroscopy) is associated with a higher detection rate of urinary tract injuries compared with visual inspection alone, particularly for ureteral injuries. In a systematic review and meta-analysis of 79 studies that included multiple types of benign gynecologic surgeries, nearly twice as many ureteral injuries were detected with routine use of cystoscopy than without (1.6 versus 0.7 per 1000 surgeries) [1]. A higher detection rate with cystoscopy was also reported for bladder injuries, although the impact was not as large (1.0 versus 0.8 injuries per 1000 surgeries detected with cystoscopy use or non-use). Specific to hysterectomy, a retrospective cohort study from an academic center that instituted universal cystoscopy at the time of hysterectomy reported significantly fewer delayed urologic complications in the postuniversal cystoscopy patients compared with the preuniversal cystoscopy group (0.1 versus 0.7 percent) [6]. The observed reduction in delayed complications likely resulted from a reduction in vesicovaginal fistula (7 cases preuniversal cystoscopy to 0 cases postuniversal), presumably because of the significant increase in recognized bladder injuries in the postuniversal cystoscopy group (85 postuniversal screening versus 52 percent preuniversal).

Clinical use of cystoscopy in the diagnosis of operative urinary tract injury is discussed separately. (See "Urinary tract injury in gynecologic surgery: Identification and management", section on 'Cystoscopy' and "Diagnostic cystourethroscopy for gynecologic conditions", section on 'Procedure'.)

Impact of procedure type — The incidence of urinary tract injury at gynecologic surgery varies by the type of procedure and route of surgery (ie, vaginal, laparoscopic, robot-assisted, or abdominal), which are influenced by the surgical indication, underlying pathology, degree of anatomic distortion, and surgeon experience.

●(See "Surgical management of stress urinary incontinence in women: Choosing a type of midurethral sling", section on 'Complication comparison'.)

●(See "Pelvic organ prolapse in women: Surgical repair of apical prolapse (uterine or vaginal vault prolapse)".)

RISK FACTORS — Risk factors for urinary tract injury in pelvic surgery are based upon characteristics of the patient or procedure [1,2,7].

Patient characteristics — Patient risk factors that impact urinary tract complications are conditions that distort pelvic anatomy, obscure tissue planes, make visualization of urinary tract structures difficult, or make the urinary tract more vulnerable to injury [2,5,7-9]. These include:

●Prior pelvic surgery

●Endometriosis

●Urinary tract abnormalities (eg, duplicated ureter, pelvic kidney)

●History of pelvic irradiation

●Obesity

●Large pelvic mass

●Fibroids, including in the cervix and broad ligament

●Large uterus (>250 g)

Specific to pelvic surgery, prior laparotomy or cesarean delivery was associated with higher rates of bladder and/or ureteral injury in studies of hysterectomy with 1000 or more women; the rates were compared with patients who had not previously undergone these procedures [10,11]:

●Previous laparotomy – 2.1 versus 0.5 percent

●Previous cesarean delivery – 2.9 to 4.7 versus 0.7 to 1.1 percent

The risk of urinary tract injury during pelvic surgery increases with increasing number of prior cesarean deliveries. A retrospective case-controlled study reported unintentional cystotomies were significantly higher in patients with two or more cesarean deliveries compared with no prior cesarean delivery (8 versus 2 percent). In patients with two or more cesarean deliveries, the risk of bladder injury varied with the surgical route (6 percent for total abdominal hysterectomy, 11 percent for total vaginal hysterectomy, and 21 percent for laparoscopic-assisted vaginal hysterectomy). In multivariate analysis, the risk of bladder injury was highest among patients with four prior cesarean deliveries (odds ratio [OR] 8.70) [12].

A large population-based study reported Black race as a risk for bladder injury [9]. Presumably, this increased risk of urinary tract injury by race is attributed to a greater incidence of large uteri and uterine fibroids among Black women undergoing hysterectomy [5,9].

There are no data that quantify the risk of urinary tract injury in women with a history of pelvic irradiation, urinary tract abnormalities, obesity, or a large pelvic mass.

Procedural factors — Urinary tract injury occurs almost exclusively in major gynecologic surgery that involves surgical dissection in proximity to the ureters or bladder. Minor procedures (eg, hysteroscopy) or tubal surgery are rarely associated with this type of complication.

Procedural risk factors involve the indication and type of procedure [1,2,7,8,13-15]:

●Surgery for malignancy

●Advanced pelvic reconstructive surgery

●Laparoscopic or robotic hysterectomy

A large database study using the American College of Surgeons National Surgical Quality Improvement Program reported that minimally invasive hysterectomy (laparoscopic or robotic) was an independent risk factor for ureteral injury (OR 4.20) [16]. Vaginal route for hysterectomy tends to have lower rates of ureteric injuries and lower occurrences of endoscopic stenting and ureteric procedures than open or laparoscopic routes [1,5], likely related to selection of this route for smaller uteri and less complex surgeries.

Data are inconsistent regarding whether characteristics of the individual procedure (surgeon assessment of operative difficulty, operative duration, volume of blood loss) are associated with urinary tract injury [7,8]. Increasing experience of the surgeon has correlated with a decrease in the frequency of urinary tract injury in some studies [11,17,18]. Other reports vary regarding whether participation by surgical trainees increases the risk of injury [19,20].

ANATOMY

Ureters — The pelvic ureters are retroperitoneal structures that run from the renal pelvis to the bladder and can be injured during pelvic surgery at any point along their distal course (figure 1). The pelvic course of the ureters and most common sites of injury from superior to inferior can be summarized as follows [21-23]:

●The ureters enter the pelvis at the pelvic brim where they cross from lateral to medial, and anterior to the bifurcation of the common iliac arteries. At this point, the ureter runs just medial to the ovarian vessels (picture 1).

●The ureters then descend into the pelvis within a peritoneal sheath (ureteric fold) attached to the medial leaf of the uterine broad ligament and the lateral pelvic sidewall (figure 2 and figure 3).

●Just inferior to the internal cervical os, the ureter passes under the uterine arteries in the cardinal ligament through a tunnel of areolar tissue to the anterolateral surface of the cervix (figure 1 and figure 4).

●The ureters then pass close to the anterolateral fornix of the vagina and enter the posterior aspect of the bladder.

Bladder — The bladder is positioned anterior to the vagina, cervix, and lower uterine segment. The vesicouterine fold, or pouch, is a reflection of the anterior peritoneum that lays between the dome of the bladder and the lower uterine segment. The base is opposed to the cervix and vagina with the vesicocervical and vesicovaginal fascia.

The bladder is divided into the dome superiorly and the base inferiorly [21,24]. The base contains the trigone, including the ureters, which enter posteriorly, and the urethra, which exits at the most inferior aspect of the bladder.

PATHOGENESIS

Mechanisms of injury — There are many ways the lower urinary tract can be compromised during or after surgery. Thermal damage from electrosurgery or other energy sources, such as laser or harmonic scalpel, is becoming a more frequent cause of injury to the urinary tract [25,26]. The expected thermal spread from devices ranges from 2 to 22 mm. In a systematic review of 90 studies, electrosurgery was the most common cause of ureteral injury (33 percent) while lysis of adhesions was the most common cause of bladder injury (23 percent) [4]. (See "Overview of electrosurgery", section on 'Thermal spread'.)

Additional potential mechanisms of intraoperative ureteral injury include [7]:

●Crushed with a clamp

●Kinked or ligated with a suture or staple

●Lacerated or transected during sharp or blunt dissection or while using an energy source

●Devascularization or denervation

Other mechanisms of intraoperative bladder injury include:

●Cystotomy

●Laceration of the bladder wall with or without or breaching the bladder lumen

●Devascularization or denervation

●Accidental placement of an intravesical suture or staple – An intravesical suture may be symptomatic or asymptomatic, depending upon the type and location of the suture/staple in the bladder and coincident infection and/or stone formation

Postoperatively, physiologic and pathologic processes can cause or exacerbate an injury to the urinary tract. These include edema, inflammation, hematoma, infection, abscess formation, ischemia, or necrosis.

Sequelae of injury — Potential consequences of lower urinary tract injury include ureteral obstruction (resulting in hydronephrosis and possible irreversible injury which, if bilateral, can lead to renal failure), genitourinary fistula, and urinoma [27,28]. All of these immediate consequences can lead to readmission, sepsis, and death [3].

When bladder injuries present postoperatively, genitourinary fistulas appear to be the most common presentation (74 of 76 in one series) [29]. Fistulas are more often associated with hysterectomy, particularly radical hysterectomy. (See "Urogenital tract fistulas in females", section on 'Epidemiology and risk factors'.)

APPROACH TO PREVENTION — Prevention of urinary tract injury and sequelae is a central principle of pelvic surgery. There are three levels for prevention [22]:

●Primary – Avoiding urinary tract injury

Primary prevention is optimal. The most important method for primary prevention is intraoperative identification of the bladder and ureters and avoidance of injury through meticulous surgical technique. In addition, preoperative identification and evaluation are used to select appropriate patients for placement of prophylactic ureteral catheters. (See 'Prophylactic ureteral catheters' below.)

●Secondary – Intraoperative recognition and repair of injury

When injuries do occur, prompt intraoperative diagnosis and management help to avoid sequelae such as ureteral obstruction and ureterovaginal or vesicovaginal fistula formation. This is accomplished through surgeon inspection of pedicle and urinary tract structures and awareness of potential signs of injury (eg, urine in the operative field). Routine use of cystoscopy is another option. (See "Urinary tract injury in gynecologic surgery: Identification and management", section on 'Screening for injury with routine cystoscopy'.)

●Tertiary – Postoperative diagnosis and treatment of urinary tract injury

PREOPERATIVE EVALUATION — Preoperative evaluation and preparation are focused on preventing operative urinary tract injury. A more general discussion of preoperative assessment for gynecologic surgery is presented separately. (See "Overview of preoperative evaluation and preparation for gynecologic surgery".)

Informed consent — Counseling about the risk of urinary tract injury is part of the informed consent process prior to pelvic surgery. This discussion should be documented in the medical record and on the consent form.

Medical history — Important elements of the history are prior pelvic surgery, radiation, or infection and known or suspected endometriosis. Congenital anomalies of the urinary tract (eg, duplicated ureters, pelvic kidney) may be suspected if there is a personal or family history of congenital anomalies of the urinary tract or reproductive tract, since these abnormalities often coexist. (See "Overview of congenital anomalies of the kidney and urinary tract (CAKUT)".)

Imaging studies — Contrast studies of the ureters may be useful in patients with known or suspected urinary tract anomalies. Preoperative imaging with computed tomography urography can be helpful in demonstrating structural abnormalities in the urinary tract [23]. Magnetic resonance imaging can be helpful in confirming the presence of cervical fibroid(s), broad ligament fibroid(s), and or retroperitoneal cysts or masses that increase the risks of urinary tract injury.

OPERATIVE SETUP

Patient positioning — Patient positioning in the dorsal lithotomy rather than supine position provides better access for evaluation of the urinary tract with cystoscopy or other methods that require access to the urethra. For abdominal hysterectomy, one option that avoids having to reposition the patient during surgery is to position the patient in lithotomy stirrups that can adjust from a low to high position (eg, Yellofin) at the start of surgery, prior to prepping and draping. A self-retaining retractor that does not interfere with the thighs (eg, Bookwalter) must be used when the patient is in lithotomy position. This setup allows a second surgical assistant to stand between the patient's legs, which improves their ability to assist. This setup also facilitates performing cystoscopy more easily, with better visualization of the entire bladder.

Bladder catheter — Placement of a bladder (Foley) catheter may be helpful in procedures in which there is a potential for urinary tract injury. If there is an increased risk of injury, a triple lumen (three-way) catheter can be used, which will allow instillation of contrast material if bladder injury is suspected. Persistent blood-tinged urine in the catheter output should prompt evaluation for urinary tract injury.

Prophylactic ureteral catheters — Universal use of prophylactic ureteral catheters is not recommended [30-32]. A randomized trial that assigned 3141 women with no prior pelvic surgery who were undergoing major gynecologic surgery to bilateral ureteral catheters versus no stents reported similar incidences of ureteral injury in the groups (1.2 versus 1.1 percent) [32]. However, there was a significantly higher rate of severe ureteral injury in the non-catheterized group [32].

Ureteral catheters are potentially helpful for selected women with known or suspected periureteral fibrosis or scarring, such as those with severe endometriosis, large cervical fibroids, or prior pelvic irradiation.

A practical barrier to ureteral catheter insertion prior to hysterectomy is the need to schedule an urologist to be available at the start of a surgical case [32]. One center performed a retrospective chart review of 337 patients in which prophylactic preoperative ureteric catheters were placed by a gynecologic surgical consultant or subspecialty trainee [33]. The catheter insertions were quick (5.4 to 8.4 minutes) and easy to insert (by gynecologists) and were associated with low complication rates.

Our approach is to perform all major gynecologic surgical cases in dorsolithotomy position with boot-type stirrups. For open cases, we use a Bookwalter retractor. For surgical cases where we anticipate complex surgery (eg, patients with severe endometriosis or large cervical fibroids), prophylactic ureteral catheters are placed in the operating room prior to the initial incision. Ureteral catheters are placed using a 22-French, 30-degree cystoscope and bridge deflector. In our practice, trainees perform the ureteral catheterization under direct supervision of an attending gynecologist who has the appropriate skills. Because we perform all major cases with patients in this position, we are able to easily perform cystoscopy and ureteral catheter insertion to minimize the risks of an injury during a difficult case to help delineate ureter anatomy.

Ureteral catheters allow the surgeon to easily palpate the ureters prior to applying clamps or ligating pedicles proximal to the ureters. This avoids the need for extensive ureterolysis in these cases where severe periureteral fibrosis will make ureterolysis more challenging and/or the surgeon does not have advanced skills in ureterolysis. Similar to other centers, we find placing ureteric catheters either just prior to (or during) difficult surgery quicker and associated with less bleeding and risk of ureteral devascularization than performing extensive ureterolysis [33].

SURGICAL TECHNIQUE — The most important principle for prevention of urinary tract injury is to develop and divide tissue planes to identify and isolate the structures of the lower urinary tract before operating on other pelvic structures. Anatomic variation and pelvic pathology may obscure tissue planes, thereby increasing the risks of an injury [1].

Avoiding ureteral injury — The most common mechanism of ureteral injury is accidental ligation or transection while operating on other structures. Identification of the ureter at each step in a procedure avoids injury [23]. The highest risk of denervation and/or devascularization is during ureterolysis; therefore, removal of all tissue surrounding the ureter should be avoided during gynecologic surgery performed for benign indications.

During oophorectomy or hysterectomy, the steps of the procedure in which the ureter is most likely to be injured are:

●Ligation of the ovarian vessels

●Ligation of the uterine vessels

●Closure of the angles of the vagina cuff

The most common site of ureteral injury is the distal ureter at the level of the uterine arteries [7,28].

Ligation of the ovarian vessels — To avoid ureteral injury when the ovarian vessels are ligated during oophorectomy (with or without hysterectomy), there are several methods of identifying the ureter: opening the retroperitoneum to visualize the ureter directly, visualizing the ureter through the peritoneum, and palpating the ureter. There are no high-quality data regarding which method is associated with a lower risk of ureteral injury. However, opening the retroperitoneum and visualizing and/or palpating the ureter prior to isolating, clamping, and ligating the ovarian vessels is the method that best ensures accurate identification and protection of the ureter.

●Opening the retroperitoneum abdominally – The following sequential steps are performed when opening the retroperitoneum abdominally (figure 1):

•Ligate and divide the round ligament to create an opening in the broad ligament [22,34].

•Palpate the external iliac artery. Continue using blunt dissection to open the broad ligament lateral to the external iliac artery and lateral and parallel to the ovarian vessels (which are within the infundibulopelvic ligament). Limit use of energy sources in close proximity to the ureter. As noted above, the expected thermal spread from devices ranges from 2 to 22 mm. (See 'Mechanisms of injury' above.)

•Expose the external iliac artery and vein.

•Dissect out the ureter from the surrounding tissue as it crosses over the vessels and is adherent to the medial leaf of the broad ligament. Visualization of peristalsis confirms that the ureter has been identified. Take care to avoid disrupting the vascular supply of the ureter, which may result in ischemia and necrosis [13].

●Visualization or palpation – When visualization through the peritoneum or palpation, rather than opening the retroperitoneum, is used to identify the ureter, it may be mistaken for other structures. During laparoscopy, visualization of the ureter is reasonable when the peritoneum is translucent and the ureter can be clearly seen. When this method is used, visualization of peristalsis confirms identification of the ureter. By contrast, palpation of the ureter is often misleading since many structures can have the same consistency as the ureter. However, in circumstances in which the ureter cannot be visualized (eg, bleeding in operative field), we use palpation to attempt to identify the ureter. The ureter has a "rubber band-like" consistency and should snap when pulled gently; the ureter does not pulsate when palpated.

During a laparoscopic approach to oophorectomy, it is our practice to visualize the ureter and its peristalsis along the pelvic sidewall. Once the location of the ureter is confirmed, we make a small incision in the peritoneum superior to the ureter but inferior to the ovarian vessels, parallel to both of these structures. This peritoneal incision serves as a visual marker (the ureter is below it). We then make a second incision more superiorly along the pelvic sidewall, above the ovarian vessels, and use these two peritoneal incisions to isolate and ligate our ovarian vessels.

Of note, during a vaginal approach to oophorectomy, the ureter is more difficult to visualize and is protected by clamping the ovarian vessels as close as possible to the ovary.

Ligation of the uterine arteries — At the level of the uterine arteries, the uterine vessels are skeletonized before ligation to visualize the ureter (figure 2). If the vessels have been isolated, it is not required to completely dissect out the ureter. When placing a clamp prior to ligating the vessels, care must be taken that only the vessels are included in the clamp. Perhaps more importantly, mobilizing the bladder from the anterior cervix and displacing it inferiorly will also shift the ureters inferior to the uterine arteries prior to clamping.

The ureters pass below the uterine vessels, and once these vessels are ligated, the ureter will pass just inferior and lateral to this pedicle. Thus, to protect the ureter during subsequent dissection of the cardinal ligament, the clamp is placed medial to the uterine artery pedicle.

Vaginal cuff closure — The ureters enter the bladder posteriorly, along its interface with the anterior vaginal wall (figure 3). Thus, care must be taken during closure of the vaginal cuff to avoid both the ureters and bladder. As the bladder is dissected off the surface of the vagina or cervix and displaced inferiorly, the ureters will descend with the bladder to a level safely below the superior aspect of the cuff.

Avoiding bladder injury — Injury to the bladder may occur while dissecting the bladder away from the lower uterus, cervix, and upper vagina during hysterectomy. This tissue plane is usually easy to find and dissect, whether a hysterectomy is being performed from a laparoscopic, abdominal, or vaginal approach. However, one or more previous cesarean deliveries may cause fibrosis and scarring. In this setting, there is increased difficulty in dissecting the tissue plane with a higher risk of bladder injury.

We use sharp dissection, with or without electrosurgery, whether the dissection is easy or difficult. We do not perform blunt dissection when developing this tissue plane. Blunt dissection may result in increased bleeding or tearing of the bladder. Bladder injury that occurs with sharp, rather than blunt, dissection can often be easier to repair.

In laparoscopic surgery, injury to the bladder usually occurs during secondary trocar insertion. Bladder injury can be avoided by placement of the secondary trocar under direct visualization and by making certain that the bladder is emptied before trocar placement. (See "Complications of laparoscopic surgery", section on 'Bladder puncture'.)

Intraoperative maneuvers — At abdominal hysterectomy, having the first assistant constantly pulling the uterus up, while the surgeon mobilizes the bladder and ligates the uterine arteries and the cardinal/uterosacral ligaments, facilitates descent of the bladder and ureters away from these structures, decreasing the risk of injury. During laparoscopic hysterectomy, having the second assistant constantly pushing the uterus up accomplishes the same maneuver. At vaginal hysterectomy, placing clamps and suturing pedicles as close as possible to the cervix and uterus decreases the risk of ureteric injury.

Identifying a pelvic kidney — A pelvic kidney, which occurs in from 1 in 500 to 1 in 3000 individuals, may be encountered during gynecologic surgery. They are usually unilateral, retroperitoneal, irregular in shape, and may occur anywhere below the pelvic brim. The blood supply is invariably anomalous, often with branches coming from the aorta, common, external or internal iliac vessels, and vessels may come from both sides of the pelvis [35]. However, with increased access to high-quality preoperative imaging, intraoperative discovery of a pelvic kidney should be a rare occurrence.

Identification of an unsuspected pelvic kidney reduces the risk of damage to the kidney or its blood supply. During surgery, the presence of a retroperitoneal mass or anomalous ureteral anatomy suggests the presence of a pelvic kidney. During laparotomy, identification of a pelvic kidney can be made by palpating the abdominal retroperitoneum to confirm that there is no abdominal kidney, and then by identifying the ureter which exits the pelvic kidney [36]. Intraoperative sonography may also be used to identify a pelvic kidney. In general, biopsy is avoided if a mass is suspected to be a pelvic kidney as biopsy can lead to bleeding and organ injury.

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: Gynecologic surgery".)

SUMMARY AND RECOMMENDATIONS

●Urinary tract injury during female pelvic surgery occurs in approximately 0.3 to 1 percent, and may be as high as 2.4 percent of procedures. Injury rates vary by procedure type and anatomic location (bladder or ureter). Cystoscopy detects more urinary tract injuries compared with visual inspection alone, particularly for ureteral injuries. (See 'Incidence' above.)

●The morbidity for recognized and unrecognized ureteric injuries (including sepsis and urinary tract fistulae) is high. Acute renal failure and death are higher for unrecognized versus recognized ureteric injuries. (See 'Incidence' above.)

●Risk factors for urinary tract injury include increased body mass index, prior pelvic surgery, one or more prior cesarean deliveries, endometriosis, broad ligament and/or cervical fibroids, large uteri, urinary tract abnormalities, surgery for malignancy, and surgery for urinary incontinence or pelvic organ prolapse. (See 'Risk factors' above.)

●For women with known or suspected urinary tract anomalies, retroperitoneal cysts, and/or cervical/broad ligament fibroids, we suggest preoperative imaging, preferably magnetic resonance imaging or computed tomography scan with contrast. (See 'Imaging studies' above.)

●Urinary tract injury may occur via laceration, obstruction, or thermal injury from a surgical instrument; a suture, a stapling device, or an energy source; or as a result of devascularization or denervation. Potential immediate consequences of lower urinary tract injury include ureteral obstruction (resulting obstructive nephropathy), genitourinary fistula, or urinoma. These can lead to readmission, nephrostomy tube placement, renal failure, sepsis, and death. (See 'Pathogenesis' above.)

●For most women undergoing gynecologic surgery, we recommend not using prophylactic ureteral catheters (Grade 1B). We suggest use of prophylactic ureteral catheters for women with severe endometriosis, large cervical fibroids, or a history of pelvic irradiation (Grade 2C). In these situations, ureteral catheters can be inserted either prior to surgery or intraoperatively. (See 'Prophylactic ureteral catheters' above.)

●The most important principle for prevention of urinary tract injury is to develop and divide tissue planes to identify and isolate the structures of the lower urinary tract before operating on other pelvic structures. (See 'Surgical technique' above.)

●During oophorectomy, at the level of the ovarian vessels, if the ureter can be clearly visualized through the retroperitoneum, opening the retroperitoneum is not routinely required. If the ureter cannot be clearly visualized, we suggest opening the retroperitoneum (Grade 2C). We suggest not using palpation as the sole method of identifying the ureter (Grade 2C), although palpation alone may be required when the ureter cannot be visualized.

●During hysterectomy, the most common site of ureteral injury is the distal ureter at the level of the uterine arteries. Other steps of the procedure associated with injury to the ureter are ligation of the ovarian vessels (during concomitant oophorectomy) and vaginal cuff closure. (See 'Surgical technique' above.)

●During hysterectomy, constant upward tension (for open hysterectomy) or elevation (for laparoscopic hysterectomy) of the uterus causes inferior displacement of the ureters and decreases risk of urinary tract injury when ligating the uterine arteries, cardinal, and uterosacral ligament complexes. Additional techniques include skeletonizing the uterine vessels prior to clamping and dissecting the bladder off the underlying vaginal surface prior to closing the vaginal cuff. (See 'Avoiding ureteral injury' above.)