Discussion
Our research has that the type of ureteral injury is a crucial factor in urological intervention decisions and treatment efficacy in IUI. We observed that it was more often diagnosed in the postoperative period if IUI was caused by thermal injury. Endourological interventions were performed more frequently in cases, and half of those procedures required repeated urological interventions.
IUI incidence has increased due to the rise in the overall number of surgeries and the widespread use of minimally invasive surgical techniques (2, 3). The most common causes of ureteral trauma are suture ligation, blunt injury, partial/total transection, and ischemia due to thermal damage (20). Early detection of trauma and immediate ureteral correction surgery reduces kidney and ureter related complications (7, 21). In postoperative IUI cases, sepsis (Odds Ratio: 11.9), urinary fistula (Odds Ratio: 23.8), and mortality (Odds Ratio: 1.4) are more common than those diagnosed perioperatively (22). More repetitive urological interventions may be required in (23).
Approximately three-quarters of IUI malpractice litigation end up against surgeons. Prolonged urinary leakage, delayed ureteral reconstruction, inattentive postoperative care, and insufficient surgical training are the most common accusations (24). Therefore, it is essential to choose the appropriate treatment in IUI.
The recommended treatment in IUI is ureteroureterostomy or ureteral reimplantation according to the traumatic ureter segment (8, 10, 11, 25).  However, endourological approaches are often chosen as initial care due to short hospital stay, fewer complication, and low treatment cost (26). Reported success rates for endoscopic IUI management range from 17% to 84% (13-18). In study, we initially treated 59.25% (n = 16/27) of the patients with endourological methods.
Endourological intervention recommended in patients with a ureteral stenosis segment smaller than 2 cm or a small fistula tract with a mostly preserved ureter wall (16). Successful results have been reported antegrade stent approach with endoscopic ’rendezvous’ method in patients diagnosed with postoperative IUI (12). Delayed diagnosed IUI treated with endoscopic realignment for partial or complete transected ureter in 11 patients had a 45.46% (n = 5/11) ureteral stricture at the follow-up. The authors concluded that ureteral stenosis frequency is high in IUI cases, and patient selection is the main factor for treatment success (14). 1185 (n = 9/76) of the cases due to thermal injury and others to suture ligation (18). In a study including 76 IUI cases, 29 patients diagnosed during the perioperative period underwent open reconstructive surgery, and all recovered without complications. Forty-seven patients were diagnosed late, a double loop stent was placed with an endourological approach, and only seven of these recovered without complications (27).
In studies, the type of ureteral injury was not specified. Because of the heterogeneity in IUI etiology, the low incidence of cases, and the variety of treatment choices, success rates of treatment results may have spread over a wide range.
There are a limited number of publications investigating IUI due to thermal damage (28). Tissue coagulation devices that work with ultrasonic-based energy vary depending on the device’s technical features but can cause an increased temperature between 33-100 ° C on the surrounding tissue (29) and lateral spread may 10 mm. In ultrasonically activated electrocautery, the temperature rises very quickly up to 350 ° C, and the lateral spread can reach up to 22 mm (30). These tissue heat quantities are higher than 60 ° C, even at 25 mm from the device. Therefore, it has been shown that ultrasonic electrocoagulation devices causes significant histological damage in thin-walled organs such as the ureter, which cannot be detected macroscopically (31). While performing thermal ablation of a mass in the renal hilum, it has been reported that ureteropelvic junction stenosis developed in the postoperative follow-up due to thermal damage without any perioperative complications (32).
We detected 85.71% (n = 6/7) of patients with cold transection IUI during gynecological surgery. This rate was 35% (n = 7/20) in thermal injuries, which was statistically significantly lower than cold transection (Table 2). Almost one-third of the thermal injuries could not recognize perioperative settings, supporting previous studies (31). Thermal injury cases were mostly treated endoscopically and had higher complication rates than the cold transection IUI (Table 3).
We believe that high complication rates are observed in patients treated with endourological intervention after thermal IUI since the traumatic ureter segment was not excised. Although the endoscopic surgical method did not fail in the early period, we observed complications due to ureter in half of the patients during follow-up. Therefore, in our opinion, surgical techniques in which the traumatic part of ureter is excised should be preferred in suspected thermal IUI cases to avoid complications (such as stricture or fistula).
The study’s limitations are the retrospective nature and a low number of cases due to IUI characteristics, and the lack of knowledge of the energy setup of energy-based surgical instruments used during ureter dissection.