Almost all UVFs are linked to an iatrogenic lesion, which usually follows pelvic and gynecological surgery [7, 8]. It occurs as one of the rare and serious surgical complications . The incidence of UVF can be attributed to the surgical technique  and its technical difficulty , although the risk factors for the underlying pathology of individual patients are not identical. Based on the surgical history, clinical symptoms, and auxiliary examination, diagnosis of UVF is not complicated .
For economic reasons, many surgeons dislike taking a patient who has undergone previous ureteral surgery, so UVF patients are often difficult to diagnose intraoperatively , with a median time to diagnosis of 3–30 days post injury. The basic tenet in treating a UVF is to restore the continuity of the urinary tract, protect kidney function, reduce localized stenosis, and avoid urinary fistula formation .
Due to secondary renal damage resulting from ureter-repair surgery or reconstruction, preoperative excretory urography or other auxiliary methods are needed to determine contralateral renal function, which is of great value in deciding how to deal with the damaged ureter. Urologists should adopt a comprehensive protocol according to the type, position, and degree of injuries.
Although the success rate, operative complications, and long-term outcome of traditional early surgical treatment for UVF are similar to delayed operation [15, 16], we suggest that UVF repair surgery or ureteric reimplantation be completed in the early stages [17, 18], which might avoid renal damage and reduce patient’s pain and financial burden. Generally, first-stage repair surgery should be available intraoperatively or within 24 h after ureteral injury. But for the delayed diagnosis cases and severe shockers with complicated injuries, repair surgery should be put off for 3–6 months after urine transfer .
In recent years, retrograde ureteric stenting has been recommended for the first stage of UVF, which reduces urine leakage in internal drainage and in inflammatory lesions . UVF can typically be treated successfully by ureteric stenting as long as the ureter wall is continuous.
Generally speaking, there is no need to disconnect the ureter during transurethral ureteroscopy and retrograde stenting, UVF can typically be treated successfully by placing a D-J stent ,which can replace the patient’s mental and physical trauma with easy acceptance, short hospitalization time, and fast recovery. Even if the UVF fails to heal, it can be used in first-stage treatment in full drainage to protect renal function and lay a good foundation for stage II surgery.
For some severe ureteric injuries, retrograde stenting is sometimes unsuccessful. Combining our practice with the literature review, we believe that the realignment retrograde/antegrade stenting approach is feasible by inserting the guide wire into the injury from the percutaneous nephroscope channel  and using the ureteroscope to grasp the guide wire out from the urethra, then pass the D-J stent along the guide wire and over the injury.
In a minority of situations, in which a patient presents with a severe ureteral injury—completely lacerated or atretic—such that a guide wire cannot be passed in either in a retrograde or antegrade fashion, endoscopic realignment for treatment and “cut-to-the-light” technique should be employed .
Compared with retrograde stenting, the extravasation of urine and washing fluid can be smoothly accomplished provided there is sufficient time and operating space for surgery. It would made stenting easier, more readily available, safer, and less invasive.
Therefore, it is appropriate for patients with a history of open pelvic and radical gynecologic surgery, multiple casualties, and those with severe fever, local inflammatory reaction, or severe shock.
Additional advantages of this method are as follows:
It is easy to find both ends of ureteral injury and approach its focus along the nephrostomy channel by means of double ureteroscopic realignment, which increases the success rate of prograde or retrograde ureteric stenting, avoiding additional surgery, or ureteric reimplantation or placement of a percutaneous nephrolithotomy (PCN) tube.
It ensures that the guide wire reaches the injury using direct vision and avoids exacerbating the ureter injury during adjustment of the guide wire’s position and direction during the procedure.
It is particularly appropriate for patients with failing retrograde ureteric stenting; patients who suffer from a severed ureter, severe injury, or ureter distortion; those who cannot tolerate long-term indwelling of a urinary catheter; and those with an advanced tumor.
The flank-reclining, split-leg position provides sufficient operating space to perform a PCN and retrograde ureteroscopy simultaneously.
Although the endoscopic realignment was successfully used, some obvious disadvantages of the method are as follows: In some cases with normal or mild hydronephrosis, it is difficult to gain access to a nondilated renal collecting system because of urine leakage.The ureter is easy to collapse and block after pulling out the ureteral stent in patients who have long suffered from defects of ureteric avulsion or transection (usually > 2 cm), serious stricture formation, repeated surgeries, or serious fibrosis of the ureteral surroundings. In addition, this procedure should be performed before the flexible ureteroscopy’s light no longer penetrates the tissue between the ureteroscopes. However, more studies with longer, consecutive follow-ups and mass cases are necessary to predict prognosis in the future.