Injury to the urinary tract involving the ureter and urinary bladder is a rare but recognized complication of hysterectomy, given the close anatomic relationship between the genital and urinary structures.1 The majority of these injuries occur during gynecologic operations, with reported rates for bladder injury ranging from 0.2–1.8% and for ureteral injuries from 0.03–1.5%.1–3 The true figure is uncertain, and many intraoperative injuries go unrecognized, contributing to postoperative morbidity, including the loss of a kidney. Injuries not corrected during the initial hospitalization may result in serious disruption in the patient’s quality of life and probable medical–legal action.4 A lack of consensus exists on the most efficient and reliable means to minimize urinary tract injuries in gynecologic surgery. Various reviewers have differed their in opinions regarding the use of preoperative and intraoperative procedures such as intravenous pyelography, cystoscopy, and ureteral catheters.5,6 Many injuries may not be recognized at the time of surgery, and ureteral injuries may never be recognized until years later. Diagnostic cystoscopy is not routinely performed by many gynecologic surgeons, either because of lack of training or difficulty in obtaining privileges to perform this urologic procedure.7 The ease of performing diagnostic cystoscopy, a low-risk procedure, and morbidity associated with missed urinary tract injuries8 make an argument for the routine use of intraoperative cystoscopy with hysterectomy.
Common sites of ureteral injuries are at the level of the infundibulopelvic ligament, the distal uterosacral ligament as the ureter courses under the uterine artery and before its insertion into the urinary bladder.8 There are differing descriptions of the most likely location for injury to the ureter, depending on whether the procedure is abdominal or vaginal or whether prolapse surgery is performed. In cases with ureteral obstruction diagnosed on cystoscopy, the primary finding that prompts suspicion is the sluggish or absent efflux of dye from the ureteral orifices. The finding of sluggish or delayed flow may cause anxiety to the surgeon and is a reason for further evaluation.
Our study evaluated the use of intraoperative cystoscopy for the detection of urinary tract injury after hysterectomy. The ureteral injuries were also evaluated to estimate the most common site of injury. We also examined the nature of the injuries as well as the problem of subnormal ureteral efflux in the absence of injury.
MATERIALS AND METHODS
The study began in August 2000 with patient enrollment from three sites of the Louisiana State University Health Sciences Center at New Orleans, Lafayette, and Baton Rouge, Louisiana. Patient enrollment was continued at University Medical Center, Lafayette, after Hurricane Katrina and in New Orleans after reopening of University hospital and remains ongoing. The study was granted approval by the Institutional Review Board of the Louisiana State University Health Sciences Center at all sites, and informed consent was obtained from all patients before enrolment. Patients were not charged, and therefore the funding was internal. This phase of the study now has a total enrolment of 839 patients. Patients aged older than 18 years undergoing a hysterectomy for benign disease were recruited. Patients scheduled to have a concomitant procedure for pelvic organ prolapse or urinary incontinence were recruited. Study exclusions were patients with malignant disease and those with a previous hysterectomy. The Health Information Portability and Accountability Act forms were also signed at the time of enrolment. Gynecologists in training, supervised by an attending gynecology or urogynecology surgeon, performed all surgeries. A study data sheet was used to record case information such as patient demographic data, primary surgery, incontinence and prolapse surgery, surgical indication, bladder and ureteral injury, injury repair, blood loss, and operating time.
Visualization of ureteral peristalsis was the initial intraoperative method to detect injury during the procedure. Rigid cystoscopy was performed at the end of every hysterectomy or after additional prolapse procedures. All injuries were repaired during the primary surgery by the attending gynecologist or by a consulting urogynecologist. Indigo–carmine dye was administered intravenously, and efflux of dye from the ureteral orifices was observed on diagnostic cystoscopy. The initial action after the sluggish or absent flow of dye from either ureteral orifice was the administration of an intravenous fluid bolus, and in some cases, a small dose of diuretic. Persistence of the problem was addressed by the passage of a ureteral stent on the affected side(s) by an urogynecologist. Difficult stent passage was immediately followed by ureteral exploration and repair.
A computer database was created (Microsoft Excel, Microsoft Corp., Redmond, WA), and statistical analysis used SPSS statistical software package (SPSS Inc., Chicago, IL). Descriptive statistics were used to present the data. We used χ2 for analysis, with Fisher exact test substituted when applicable. P<.05 was considered significant.
There were 24 cases of urinary bladder injury (2.9%) and 15 cases of ureteral injury (1.8%). The combined urinary tract injury rate was 4.3%, taking into account three cases with simultaneous bladder and ureteral injury. Vaginal hysterectomy was associated with a higher number of cystotomies when concomitant prolapse surgery is performed (0.4% compared with 2.2%). Ureteral injury occurred in 1.7% (9/529) of total abdominal hysterectomy cases, 2.6% (6/227) of transvaginal hysterectomy cases(Table 1). This difference was not significant and there were no ureteral injuries in the laparoscopically assisted vaginal hysterectomy cases.
Cystoscopic detection of urinary tract injuries (including confirmation of those that were initially detected visually) occurred in all but one case. This particular undetected injury occurred in a patient who developed a vesicovaginal fistula several weeks after discharge. The detection rate was 97.4% (817 of 839 cases; 95% confidence interval 96.3–98.5) for all injuries. Injury detection by visual inspection was noted in 25.6% of all injury cases. A breakdown according to type of injury shows that for ureteral injuries, visual detection occurred in 1 of 15 cases (6.7%), and 9 of 24 cases (37.5%) of bladder injury were visually detected (P<.001). In all cases where visual detection was the initial means, a diagnostic cystoscopy was still performed. All of these visually detected injuries were confirmed on cystoscopic examination as the default procedure.
With respect to risk factors and surgical variables, the uterine size, operating time, body mass index, and blood loss were examined. Table 2 documents demographics and variables among primary surgery groups with no injury compared with those cases with urinary tract injuries. Ureteral injuries were further characterized by type and site of injury (Table 3). The most common types of injuries were ureteral transection (6 of 15 or 40%) and kinking (6 of 15 or 40%). These injuries occur most frequently at the level of the ureteral junction with the uterine artery in 80% of cases.
There were 21 cases in which cystoscopic examination revealed abnormal (sluggish or absent) flow of indigo–carmine dye through one or both ureteral orifices, with subsequent findings of no injury on further evaluation. These comprised 2.4% (21 of 839 cases) of the entire study cohort.
This prospective study was designed to estimate the urinary tract injury rate and location of the injury after hysterectomy. Our results were higher than previously reported by other investigators.1,3,4 The difference in injury occurrence with abdominal and vaginal hysterectomy was not significant; however, concurrent prolapse surgery with vaginal hysterectomy was associated with a significantly increased risk of urinary tract injury. The injury detection rate using diagnostic cystoscopy was 97.4% for all injuries and consistent with our previous study. Gynecologists in training are not routinely instructed in the use of cystoscopy in many training centers,8 and its routine use in gynecologic surgery remains unpopular. In our institution, residents perform all the diagnostic cystoscopic procedures intraoperatively and are comfortable with the use of the cystoscope before leaving training. Drawbacks to the adoption of universal cystoscopy after hysterectomy include the increased time under anesthesia, especially if a video setup is used in a teaching setting. Given the increased morbidity associated with unrecognized urinary tract injuries9 or delay in diagnosis,10 there is increased cost in cases of reoperation to repair these injuries. A decision analysis model concluded that routine cystoscopy would be cost-saving when the rate of ureteral injury is above 1.5% and 2.0%, respectively, for total abdominal hysterectomy and transvaginal hysterectomy.11 The results of our study suggest that in fact the rate of injury warrants the use of diagnostic cystoscopy after hysterectomy.
The issue of preoperative placement of ureteral stents12,13 and evaluation with the use of intravenous pyelography and ultrasonography remains controversial or untested.14 No prospective trials have evaluated these questions. A retrospective review concluded that preoperative evaluation may be useful in selected cases, but it was also admitted that preoperative measures have not resulted in a reduction in intraoperative injuries.15 The only risk factor for injury was blood loss greater than 800 mL and increased operating time. Degree of difficulty (determined by the resident performing the case) was not significant, but unexplained is the increased injury rate with increased body mass index and increased uterine size (Table 2). This decrease is probably due to the low frequency of injury. Operating time included the time to repair the injury.
The most common site of ureteral injury in our study was at the level of the uterine artery. The ureter is difficult to visualize or palpate once it goes under the uterine artery and courses along the anterior vagina before entry into the bladder. The distance between the ureter and the cardinal ligament–uterosacral ligament complex is small.16 Indiscriminate clamping across the vaginal cuff or inadvertent suturing, sometimes in the presence of bleeding, with poor visualization or nonvisualization of the ureter, probably led to these injuries.
Transection and kinking injuries occurred most frequently in our cohort. Ureteral kinking was relieved by suture removal and by inserting ureteral stents to maintain patency. Vaginal hysterectomy was associated with more ureteral injuries than abdominal hysterectomies (2.6% compared with 1.7%). When a prolapse procedure was performed at the same time, the injury rate was significantly increased with vaginal hysterectomy. These injuries occurred at the time of performance of uterosacral ligament suspension or McCall’s culdoplasty with inevitable surgical deviation of the ureters. Even though no ureteral injuries were noted during laparoscopically assisted vaginal hysterectomy in our study, the total number of laparoscopic cases was inadequate for conclusions. The 3.3% cystotomy rate with laparoscopically assisted vaginal hysterectomy was not significant. More injuries occurred with vaginal surgery than abdominal surgery, reflecting our predominant use of the vaginal route for prolapse repair.
The cystoscopic finding of poor or absent flow of dye through the ureteral orifices is a worrisome event and should prompt further measures and evaluation. In our study, 21 patients had abnormal flow, and the problem resolved after the initial measure of an intravenous fluid bolus with or without the aid of a small dose of diuretic. No further measures were undertaken once the ureteral jets were confirmed to be brisk and sustained over a period of 5 to 10 minutes. When there was abnormal flow bilaterally, it was indicative of a prerenal cause. In those cases of unilateral abnormal flow, the initial measure was still to administer intravenous fluids. Ureteral stents were inserted to improve patency and flow on the affected side and exploration was performed to determine a possible cause. In four cases, where stent passage was difficult or impossible, the ureteral stents were left in place after exploration and removed postoperatively. It is difficult to distinguish minor kinking with no sequelae from a kinking that compromises ureteral flow with resultant complications. In this study, patients with poor flow may have had minor kinking, but we had no adverse follow-up in this group.
There are noteworthy limitations to our study. Because of the relative small number of lower urinary tract injuries, the study has taken many years to perform to collect reliable data.
As acknowledged in the initial report of results, the surgeons were not blinded to the outcomes and were aware of the patients’ status as study participants. The supervision in our program requires strict attending surgeon presence, which should counter the effect of all cases being performed by residents. Most procedures were standard surgical technique, with the use of harmonic and bipolar energy limited to the laparoscopically assisted vaginal hysterectomy group.
The true incidence of asymptomatic cases of undetected urinary tract injury is difficult to ascertain; however, only one patient in the study presented with an injury postoperatively. The overall urinary tract injury rate of 4.3% is higher than has been generally reported in the literature.1,3,4 It has been established that total vaginal hysterectomy with a concurrent prolapse procedure places the patient at an increased risk for urinary tract injury.11 Intraoperative evaluation of the ureters and bladder during vaginal procedures is more difficult given the limited operating field and the anatomic distortion. Cystoscopy is a simple procedure to evaluate a silent injury to the urinary system. The adoption of universal cystoscopy after all hysterectomies is recommended. This will allow the immediate repair of these injuries, reducing the morbidity and decreasing the chance of a medical– legal outcome. The commonest site of injury to the ureter is at the level of the uterine artery, with transection and kinking injuries being the most frequent.
1. Liapis A, Bakas P, Giannopoulos V, Creatsas G. Ureteral injuries during gynecological surgery. Int Urogynecol J Pelvic Floor Dysfunct 2001;12:391–3.
2. Dandolu V, Mathai E, Chatwani A, Harmanli O, Pontari M, Hernandez E. Accuracy of cystoscopy in the diagnosis of ureteral injury in benign gynecologic surgery. Int Urogynecol J Pelvic Floor Dysfunct 2003;14:427–31.
3. Harkki-Siren P, Sjoberg J, Tiitinen A. Urinary tract injuries after hysterectomy. Obstet Gynecol 1998;92:113–8.
4. Sack RA. The value of intravenous urography prior to abdominal hysterectomy for benign gynecologic disease. Am J Obstet Gynecol 1979;134:208–12.
5. Wu H, Yang PY, Yeh GP, Chou PH, Hsu JC, Lin KC. The detection of ureteral injuries after hysterectomy. J Minim Invasive Gynecol 2006;13:403–8.
6. Chan JK, Morrow J, Manetta A. Prevention of ureteral injuries in gynecologic surgery. Am J Obstet Gynecol 2003;188:1273–7.
7. Hibbert ML, Salminen ER, Dainty LA, Davis GD, Perez RP. Credentialing residents for intraoperative cystoscopy. Obstet Gynecol 2000;96:1014–7.
8. Utrie JW Jr. Bladder and ureteral injury: prevention and management. Clin Obstet Gynecol 1998;41:755–63.
9. Sakellariou P, Protopapas A, Voulgaris Z, Kyritsis N, Rodolakis A, Vlachos G, et al. Management of ureteric injuries during gynecological operations: 10 years experience. Eur J Obstet Gynecol Reprod Biol 2002;101:179–84.
10. Kim JH, Moore C, Jones JS, Rackley R, Daneshgari F, Goldman H, et al. Management of ureteral injuries associated with vaginal surgery for pelvic organ prolapse. Int Urogynecol J Pelvic Floor Dysfunct 2006;17:531–5.
11. Visco AG, Taber KH, Weidner AC, Barber MD, Myers ER. Cost-effectiveness of universal cystoscopy to identify ureteral injury at hysterectomy. Obstet Gynecol 2001;97:685–92.
12. Quinlan DJ, Townsend DE, Johnson GH. Are ureteral catheters in gynecologic surgery beneficial or hazardous? J Am Assoc Gynecol Laparosc 1995;3:61–5.
13. Kuno K, Menzin A, Kauder HH, Sison C, Gal D. Prophylactic ureteral catheterization in gynecologic surgery. Urology 1998;52:1004–8.
14. Helin-Martikainen HL, Kirkinen P, Heino A. Ultrasonography of the ureter after surgical trauma. Surg Endosc 1998;12:1141–4.
15. Handa VL, Maddox MD. Diagnosis of ureteral obstruction during complex urogynecologic surgery. Int Urogynecol J Pelvic Floor Dysfunct 2001;12:345–8.
16. Tamussino KF, Lang PF, Breinl E. Ureteral complications with operative gynecologic laparoscopy. Am J Obstet Gynecol 1998;178:967–70.