Urological Injuries Due to Gynecological Operations in The Case of Benign Adnexal Lesions and Diseases and Benign Uterine Tumors

Results: In the examined group, urinary injuries were noted after hysterectomy (6 cases), uterine body amputation (8 cases), left salpingo-oophorectomy (1 case). There were 2 cases of ureter unilateral injuries and disorders a total of 4 (26.7%) cases, and 11 (73.3%) cases of bladder injury. In 13 cases, these injuries were treated intraoperatively. Reoperation in one of two cases occurred after 2 months due to adhesions of the left ureter with sigmoid, after uterine body amputation with the left ovary, in the other case it was performed on 4th day due to left ureteral severance during laparoscopic left salpingo-oophorectomy. The final surgical outcomes were satisfactory. Urological injuries and disorders secondary to major gynecological surgeries accounted for the majority of urological injuries (14 cases, 93.3%).


Introduction
Gynecological surgery carries a risk of injury to the urinary structures, especially the ureters and urinary bladder, due to their proximity to the genital organs. The occurrence of these complications is also associated with previous history of abdominal operations and pathological processes such as endometriosis and myomas in the region of the broad uterine ligaments [1]. Moreover, low expertise of a surgeon defined as less than 10 hysterectomies performed per year is enumerated among risk factors for urological injuries [2]. The identification of damage to the urinary organs during surgery allows for immediate repair, reduces the risk of possible complications, and the need for further operations [3]. Injuries to the urinary bladder, depending on the location, are classified as extra-and intraperitoneal [4]. The incidence of this complication during gynecological operations varies and depends on the type of procedure performed. The frequency of urinary bladder injury during open, transvaginal and laparoscopic hysterectomy is 0.9%, 0.6%, and 1.0% respectively [5].
The injuries to the urinary bladder are managed depending on the type and extent of injury. Bladder injuries ranging 2-10 mm can be treated conservatively, maintaining drainage with a Foley catheter for 7 days. An incision of 1-2 cm can be closed with a single layer of slow-absorbing sutures. Incisions longer than 2 cm are closed with 2-layer continuous slow-absorption sutures. The urothelium should be sutured separately and the submucosal and muscular layers repaired together with another layer of sutures.
The stitching tightness can be checked by the bladder irrigation with a solution of methylene blue. Drainage with Foley catheter should be maintained for 7-14 days depending on the damage type [6,7]. Vesicovaginal and vesicouterine fistulas are mentioned as main sequalae of the urinary bladder injury. Injury to the urinary bladder during hysterectomy carries a risk of vesicovaginal fistula (VVF), a non-physiological connection between the bladder and the vagina [5,8]. This damage can be diagnosed by a Foley catheter in the operating field or urine leak [4]. Gynecological operations occupy the third place on the list of the procedures during which ureteral injuries occur [9]. The ureters are 30-cm long ducts (the left ureter is 2-3 cm longer), 4-5 mm in diameter.
They are located retroperitoneally in the abdominal and pelvic cavity. The size, mobility and anatomical location of the ureters make them susceptible to damage [10]. Among iatrogenic ureteral injuries are loss of ureteral continuity (incision, severance) or injuries where the ureteral continuity is maintained, e.g. ligation [9]. The two most susceptible sites of intraoperative injuries are the intersection of the ureter with ovarian vessels at the suspensory ligament and with the uterine artery [1]. The risk of this complication during hysterectomy with salpingo-oophrectomy is estimated at 0.5-2.0%. The risk of ureteral injury is increased, for example, due to massive bleeding requiring management with restricted visibility and the occurrence of, among others, developmental anomalies (accessory ureters, e.g. in the case of duplex kidney, ectopic ureter entering the urinary bladder, ectopic kidney), and the history of previous surgeries or cancer [3,10,11].
In the postoperative period, urography (or pyelography) is useful to diagnose ureteral stenoses or obstruction. These examinations can be combined with contrast-enhanced computed tomography or magnetic resonance imaging. Currently, these options are considered standard in the diagnostic work-up of this type of surgical injuries [1]. Some authors argue that contrast-enhanced computed tomography offers higher sensitivity than urography in the diagnosis of ureteral injury, and the latter should be used only if computed tomography is not possible [10].
Ureteral injury with preserved continuity (in the case of ligation or clipping of the ureter) is the simplest to treat. Repair surgery consists in the removal of ligation or clamping from the ureter. In doubtful cases concerning the blood perfusion of the ligated site, the ischemic part of the ureter should be removed and repaired in a manner adjusted for the location of the injury [9,12].
Signs of injury to the ureter during or after gynecological surgery require urological consultation and subsequent surgical treatment supervised by a urologist.

Aim of The Study
The aim of study was to analyze the causes and types of urological injuries, secondary to past gynecological surgeries for non-malignant lesions of the appendages and uterine disorders and non-malignant uterine tumors.

Material and Methods
The material for retrospective analysis comprised medical       Left salpingo-oophorectomy with ovarian cyst removal. Adhesion with parietal peritoneum l-scopy < median l-tomy

Results
Tables 1 and 2 describe the type of ureteral and bladder injuries and histopathological results and pathological lesions in women undergoing surgery for non-malignant disorders of the uterus and appendages and non-malignant uterine tumors. In one case, the treatment was implemented on the 4 th day after surgery. The ureter was severed during laparoscopic removal of the left appendages due to serous cyst of the left ovary and salpingitis.
There was one case of blocked urinary outflow from the left kidney due to adhesions located in the ureteral region. This situation

Statistical Analysis
To compare the frequency of urological injuries and disorders depending on the type of surgery (total hysterectomy, subtotal hysterectomy, and laparoscopic adnexectomy), we formulated a number of hypotheses about the equality of relevant fractions.
Individual hypotheses were verified by Student's t test (Table   7A). In total, the difference in the frequency of urological injuries and disorders of the urinary organs between total and subtotal hysterectomy is not statistically significant (p = 0.61). Comparison of total hysterectomy with laparoscopic adnexectomy, and subtotal hysterectomy with adnexectomy leads to the rejection of the hypothesis of equal frequency of urological injuries and disorders (p = 0.008 and p = 0.012 respectively). This means that the differences in the frequency of these injuries in the case of total hysterectomy and adnexectomy and subtotal hysterectomy and adnexectomy are statistically significant. As for ureteral injuries and disorders, there were no differences in the frequency between particular types of surgery.
The following p values were obtained: total hysterectomy vs. subtotal hysterectomy p=0.91, total hysterectomy vs laparoscopic adnexectomy p= 0.72, and subtotal hysterectomy vs laparoscopic adnexectomy p= 0.60 (Table 7B). Bladder injuries occurred only in the case of hysterectomy, and with similar frequency after total and subtotal hysterectomy (p = 0.53). To sum up, the statistical significance of differences in urological injuries and disorders between hysterectomy and laparoscopic adnexectomy results from non-zero bladder injury rates during hysterectomy (both total and subtotal), and the absence of such injuries during adnexectomy.
In addition, we analyzed the age, body mass and BMI of patients who suffered injury to the urinary organs during surgeries for nonmalignant lesions of the genital organs and uterine benign tumors (Table 7C). The mean values of these parameters were determined for particular types of operations, and the hypotheses about their equality were verified using the Student's t test. The comparison found no statistically significant differences between these parameters for total and subtotal hysterectomy (age p = 0.15, body mass p = 0.94, BMI p = 0.58). Adnexectomies were excluded from calculations due to the sample size being too small.

Discussion
Urological injury is a complication recorded in app. 1% of all gynecological surgeries [13]. The rate of ureteral or bladder injury in gynecological surgeries is estimated at 0.5-0.8% of operated women, the rate increases to over 3% in the case of hysterectomy with salpingo-oophorectomy. According to Ibeanu et al. the likelihood of urological injury is twice as high in hysterectomy with salpingo-oophorectomy performed due to cervical or endometrial cancer ≥T2 (II according to the International Federation of Gynecology and Obstetrics, FIGO) [12].
In a publication analyzing 86 cases of urogynecological injuries in a 10-year follow-up period in patients who underwent gynecological surgery in a university hospital, the injures occurred with a total frequency of 0.30% [14]. Other researchers recorded ureteral and bladder injuries in 4.3% of all operations among 839 hysterectomies performed due to non-malignant disorders [15].
In the material presented herein, the percentage of injuries to the urinary structures during total and subtotal hysterectomy was 0.92% and 0.70% respectively ( Table 3). Injuries of urinary structures are not always identified intraoperatively. In the presented material, it happened in one case. However, blocked urinary outflow from the left kidney two months after amputation of the uterine body with left ovary is a distant complication, and is a risk factor for this type of postoperative condition (Tables 1 & 2).
In many studies evaluating the frequency of urinary injury during gynecological procedures, ureteral injury was noted in 0.1-2.5% [16][17][18][19]. However, in the analysis of 86 cases of injuries cited above, ureteral damage was reported in 0.083% [14]. It was close to the recorded rate of 0.093% injury in the discussed group (Table 3).
Korean authors reported the occurrence of ureteral injury in 1.1% of women undergoing laparoscopy, and in 1.2% laparotomies, and a significantly higher rate of ureteral injury in patients with risk factors. They concluded that gynecological procedures by laparotomy increase the chances of early detection and intraoperative repair of ureteral injury in patients with risk factors [20]. The use of techniques other than total hysterectomy for the removal of uterus may prevent urological injuries. In 1163 cases of intra-fascial and supra-cervical hysterectomies, ureteral injuries were noted in 0.34% of operated patients [21]. However, the use of other methods, e.g. laparoscope-assisted vaginal hysterectomy, increase the risk of such injury [22]. In the presented material, among a similar number (1144 cases) of this type of hysterectomy, no case of ureteral damage was noted.
However, there were two cases (0.17%) of disorders complicating the functioning of the ureters ( intraoperatively. The literature review shows that up to 70% of ureteral injuries remain unrecognized at the time of injury [22]. During open gynecological procedures, the frequency of intraoperative diagnosis of ureteral trauma reaches 30%, while during laparoscopy it is not higher than several per cent [23]. Some authors reported over 60% rate of intraoperatively identified ureteral injuries [9]. Bladder injury is the most frequent among urinary injuries sustained during is also possible to perform additional investigations or change the protocol of surgery to reduce the risk. However, in 50% of patient's preoperative identification of ureteral damage was unsuccessful [27]. In the study group, they were noted in 13 (86.7%) patients (Table 6). Another complication is the loss of blood during the procedure. Blood loss during surgery over 1 liter is a documented risk factor for bladder and ureter injury [5,8]. Such situation occurred twice in the study group.
Measures preventing urological injury include voiding the urinary bladder prior to laparotomy or laparoscopy, which reduces the likelihood of its injury during the procedure. Dissection of the bladder from the lower segment of the uterus should always be carried out sharply to protect part of its wall located over the trigone. The visualization or palpation of the ureter by the surgeon gynecologist is crucial in preventing its damage [27]. A careful surgical technique with the identification of the pelvic structures is probably the best method to prevent ureteral injury [28,29]. In order to minimize the risk of late sequelae of such injuries, the likelihood of their occurrence should always be considered and immediate action taken to recognize them. The latest study results justify and support the usefulness of routine cystoscopy in such cases, especially after hysterectomy, anterior vaginoplasty and other gynecological procedures hazardous for the lower segment of the urinary tract [15,29].