Gynecologic Oncology Consult

Preventing delayed genitourinary tract injury during benign hysterectomy

Publish date: May 23, 2019

Debate exists regarding the optimal method of evaluation of the urinary tract at the time of hysterectomy and the circumstances under which it should be performed. Procedures directed at prolapse and incontinence have rates of genitourinary injury as high as 11%-38%, and national guidelines affirm the importance of cystoscopy in these patients.¹ However, for patients undergoing hysterectomy in the absence of these procedures, the optimal strategy is debated. One approach that has been advanced is a policy of universal cystoscopy at the time of hysterectomy. This policy, by which all women undergoing hysterectomy would undergo cystoscopy, aims to prevent the occurrence of an unrecognized genitourinary injury by diagnosing and treating the injury intraoperatively. However, cystoscopy is not the only method that can be used to evaluate the urinary tract. Retroperitoneal dissection also can be used to visually identify the pertinent structures and has been performed with high fidelity by generations of experienced and skilled pelvic surgeons.

Dr. Rosa M. Polan

Injuries that are not identified intraoperatively at the time of surgery, so-called delayed genitourinary tract injuries, are associated with serious postoperative consequences for patients and high costs for institutions. As surgeons strive to decrease complications and improve the quality of gynecologic surgery, the question of whether cystoscopy should routinely be performed at the time of hysterectomy for benign indications remains unanswered. Proponents argue that cystoscopy is a low-cost assessment and that 75% of genitourinary injuries occur in women without identifiable risk factors.² Opponents point out that cystoscopy is not an entirely benign intervention; it is associated with increased rates of urinary tract infection, bladder and ureteral trauma, and additional operating room time. Furthermore, it is unclear that the use of cystoscopy will reduce the incidence of delayed genitourinary tract injury in clinical practice.

Ultimately, cystoscopy after hysterectomy is being used as a screening test for genitourinary injury, and this lens can be applied to provide more information about its usefulness. For screening tests, the sensitivity and false negative rate are of paramount importance. High sensitivity and resultant few false negatives are the characteristics of a robust screening test which has a low likelihood of missing a diagnosis. Unfortunately, the sensitivity of cystoscopy is not 100% for genitourinary tract injury; it ranges from 60% to 85% and can be as low as 43% for ureteral injury.^3,4 This means that cystoscopy will falsely reassure the surgeon with normal results in greater than 50% of the cases in which the patient actually has a ureteral injury.

Some larger series call into question the usefulness of cystoscopy as a screening tool, finding that this evaluation is not associated with a decreased rate of delayed genitourinary injury. A recent publication by our group of a series of 39,529 women who underwent benign hysterectomy without procedures directed at incontinence and prolapse recorded in the National Surgical Quality Improvement Program (NSQIP) database between 2015 and 2017 found no difference in the rate of delayed genitourinary injury among women exposed to diagnostic cystoscopy and those who were not.⁵ These results are consistent with those of the largest systematic review and meta-analysis of 79 studies capturing 41,482 hysterectomies which found universal cystoscopy was not associated with a decreased rate of delayed genitourinary tract injury.⁶

Dr. Emma L. Barber

Another consideration with the use of universal cystoscopy is cost. Although cystoscopy is typically a short procedure, the false positive rate is approximately 2%,² often leading to additional interventions to evaluate the urinary tract which can be time consuming. In the limited available data regarding operative time, patients who underwent cystoscopy had a median operative time that was 17 minutes longer than it was among patients who did not.⁵ Moreover, there may be risks associated with this additional bladder instrumentation, evidenced by an increased incidence of urinary tract infection among women undergoing cystoscopy. In a recent cost-effectiveness analysis of cystoscopy at the time of benign hysterectomy, universal cystoscopy was found to add $51.39-$57.86 per case, and the risk of bladder injury would need to exceed 21%-47% and ureteral injury 27%-38% to be cost saving, compared with selective cystoscopy.⁷ A prior cost-effectiveness analysis concluded that universal cystoscopy is cost effective when the incidence of ureteral injury at the time of hysterectomy exceeds 1.5%-2.0%.⁸ Given these high thresholds, with a contemporary composite lower–genitourinary tract injury incidence of 0.24%-0.27%, it is unlikely that universal cystoscopy could be considered a cost-saving strategy in the majority of clinical settings.

Potential explanations for these results are many. Intraoperative cystoscopy is likely to be normal in the setting of nonobstructive and thermal injuries, which in the current era of minimally invasive surgery may be more prevalent mechanisms of injury. False positives can occur leading to unnecessary interventions, as well as overdiagnosis of asymptomatic urinary tract injuries that may have resolved spontaneously.⁹ It has been observed that cystoscopy is performed less frequently when hysterectomy is completed by a high-volume surgeon, which suggests that surgeon skill and experience play a significant role in the usefulness of this evaluation.⁹

Given these data, what is the best way forward regarding evaluation of the urinary tract at the time of benign hysterectomy? Ultimately, this is a clinical question that should be individualized, taking into account patient and surgical complexity, as well as surgeon training and individual rates of genitourinary injuries.⁹ Given its low sensitivity, caution should be exercised regarding the routine use of cystoscopy alone for evaluation of the urinary tract because false negatives occur with significant frequency. Benefits of cystoscopy in a given clinical scenario should be weighed against the risks of longer operative time, increased costs, and increased rate of urinary tract infection. In the absence of clinical scenarios with high rates of genitourinary injury (greater than 5%), selective rather than universal cystoscopy is the preferred strategy.⁷ Cystoscopy is fundamentally a form of secondary prevention that aims to mitigate damage that has already been done, and is no substitute for primary prevention of genitourinary tract injury itself through thorough knowledge of pelvic anatomy, comfort with retroperitoneal dissection, and awareness of the ureter and bladder at all times.

Dr. Polan is a resident in obstetrics and gynecology at Northwestern University, Chicago. Dr. Barber is an assistant professor of obstetrics and gynecology, specializing in gynecologic oncology, at the university. Neither of them have relevant financial disclosures. Email Dr. Polan and Dr. Barber at obnews@mdedge.com.