Introduction

With the rising incidence of tumoral diseases in the pelvis, the frequency of pelvic surgical interventions is also increasing. Consequently, postoperative ureteral stenosis following pelvic surgery has become more prevalent in clinical practice [1]. In addition, as the proportion of minimally invasive surgical interventions in urology is constantly increasing, holmium laser and other high-energy lithotripsy tools have become routine surgical instruments in urology, and the application of such lithotripsy tools in the treatment of ureteral incarcerated stones may also cause irreversible damage to the ureteral mucosa. Ureteral stenosis that occurs as a complication of lithotripsy of lower ureteral stones is becoming more common in clinical practice, and this type of ureteral stenosis is a challenge for physicians [1A).

Fig. 1
figure 1

A Ureteroscope assisted laparoscopic localization of stenosis segment. B The posterior wall was sutured with the assistance of ureteroscope. C End to end ureter anastomosis was completed

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After fully dissociating the ureter, the ureteroscope was used again to support the position of the stricture. Using a pair of laparoscopic scissors close to the front of the ureteroscope, the distal end of the stenotic segment is cut first; then, the ureter toward the proximal end of the stenotic segment where ureteral dilatation is evident is slowly cut until urine is ejected. Then, after the normal mucosa of the ureteral lumen or normal mucosa of the renal pelvis could be seen, the proximal ureter was cut obliquely (If the lumen is small, cut 0.5–1 cm lengthwise at 8 o 'clock), and the distal normal ureter was cut 0.5–1.0 cm longitudinally at 3 o 'clock. With the assistance of ureteroscopy, the first three needles of the posterior ureteral wall were sutured with 4–0 absorbable suture (Fig. 1B), and then the zebra guidewire crossed the suture position into the renal pelvis. Under the monitoring of ureteroscopy and laparoscopy, the 7F double J tube was pushed retrograde. After withdrawing from the ureteroscope, the anterior ureteral wall was sutured with 4–0 absorbable sutures using 4–5 stitches intermittently. Appropriate reinforcement of the needle was performed to prevent urine leakage according to the suture situation (Fig. 1C). Complete hemostasis of the surgical area was performed after suturing was completed, and the drainage tube and urinary catheter were routinely placed beside the anastomosis.

The control group also used endotracheal intubation general anesthesia, and after catheterization, they were put in a supine position (head lower than feet) to perform simple laparoscopic ureteroplasty, 36 cases successfully carried out the removal of the narrowed section of the ureter and end-to-end anastomosis operation, Ten patients underwent ureter-bladder reimplantation, of which, three cases involved rolling the bladder muscle flaps, Normally, a drainage tube is placed next to the anastomosis.

Postoperative management, follow-up, and efficacy evaluation

Patients should rest in bed for 1–3 d after surgery (depending on the anastomotic tension). Antibiotics should be used to prevent infection routinely, proper fluids should be administered to keep urine flowing well, prevent small blood clots, and prevent urine sediments from blocking the urinary catheter. Remove the abdominal drain when it is confirmed to be clean, remove the urinary catheter 2 weeks after it was placed, and return to the hospital three months later to remove the ureteral stent. Patients need to keep a urinary catheter in place for 2 weeks because early removal after complex ureteral stricture repair can lead to urine reflux and anastomotic leakage. Patients with bladder irritation symptoms may take M receptor blockers, such as tolterodine tartrate. Follow-up is conducted for 3 to 36 months after the tube is removed, with an average of (12.6 ± 5.3) months, patients return to the hospital one week after the double J stent is removed for a urinary system CT scan and kidney function test, patients return to the hospital 1 week after the double J stent is removed for a urinary system CT scan and kidney function test, if the treatment is effective, then a urinary system CT scan and kidney function test are performed every 3 months, with at least two consecutive checks.

Observational indicators

  1. 1.

    Success rate and treatment effects of end-to-end ureteral anastomosis surgery performed on two groups of patients.

  2. 2.

    Perioperative indicators for both patient groups, including operation time, intraoperative blood loss, postoperative hospital stay, time of catheter removal, and occurrence of surgical complications.

Evaluation of the therapeutic efficiency

All patients showed reduced renal hydronephrosis on CT of the urinary system 2 weeks after catheter removal. The following conditions are deemed effective: follow-up kidney function shows a decrease in creatinine levels compared to before; the patient's lumbar pain and other clinical symptoms have eased; renal hydronephrosis remains stable over two consecutive follow-ups.

Statistical methods

Data were analyzed using SPSS 26.0 statistical software. Measurement data were expressed as mean ± standard deviation (x ± s) and subjected to a t test (when variances of two samples are equal) or an approximate t test (when variances of two samples are not equal). Count data were represented by the number of cases (%), and a χ2 test was performed. Differences with P < 0.05 were considered statistically significant.

Results

Population characteristics

There were no significant statistical differences in general clinical data such as gender, age, cause of stenosis, length of stenosis, and hydronephrosis between the observation group and control group, making them comparable (Table 1).

Table 1 Comparison of basic preoperative conditions between the observation group and the control group
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Comparison of completion rate, effectiveness, and incidence of complications of plastic surgery between patients in the observation group and the control group

In the observation group, 46 patients successfully underwent ureteroscopy combined with laparoscopic ureteroplasty, and 3 patients underwent ureteral-bladder reimplantation; in the control group, 36 patients successfully underwent laparoscopic ureteroplasty, and 10 patients underwent ureteral-bladder reimplantation, of which 3 patients underwent bladder muscle flap rolling, the success rate of ureteroplasty operation in the observation group, which was laparoscopic excision of narrowed ureter and end-to-end anastomosis, was higher than that in the control group (P < 0.05). In the observation group, only one patient developed significant gross hematuria after surgery, while in the control group, two patients developed urinoma, two patients developed postoperative fever, one patient developed vesicovaginal fistula, and one patient developed obvious gross hematuria; no patients in the observation group developed re-narrowing after catheter removal, with an effectiveness rate of 100%. The control group had three cases of re-narrowing and two cases of reflux symptoms, with an effectiveness rate of 89.13%. The total incidence of complications in the observation group was significantly lower than that in the control group, and the difference was statistically significant (P < 0.05) (Table 2).

Table 2 Comparison of completion rate, effectiveness, and incidence of complications of plastic surgery between patients in the observation group and the control group
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Comparison of perioperative clinical data between observation group and control group patients

The average operation time and intraoperative blood loss in the observation group were less than those in the control group (P < 0.05). There was no significant statistical difference in the postoperative hospital stay and drainage tube removal time between the two groups (P > 0.05) (Table 3).

Table 3 Comparison of perioperative clinical data between observation group and control group patients
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Discussion

Currently, ureteral strictures are managed in a variety of ways [5]. Endovascular surgery is often the first choice for clinical physicians because of its minimally invasive nature and rapid associated postoperative recovery [6]. Many studies have shown that in patients with a history of pelvic surgery, endoluminal procedures (be they endotomy, balloon dilation, multiple stent retention, etc.) have poor long-term outcomes and may make patients undergo multiple operations [7,8,9]. Repeated ureteroscopic surgery will not only increase the difficulty of subsequent surgical procedures but also greatly increase the psychological and physiological burden of patients and also increase the economic burden on these patients [10]. Laparoscopic ureteral stricture resection and end-to-end anastomosis have been confirmed to be effective treatment options for such ureteral strictures that occur as a result of pelvic surgery [11]. However, after pelvic surgery, the ureteral stricture is often located and dissociated due to severe scar adhesion and normal anatomical stricture; thus, it can be difficult to free the ureter above and below the stricture. If the normal ureter is injured again during the process of dissociation, it may bring devastating consequences to the normal reconstruction of the ureter [12]. Therefore, accurately locating the ureteral stricture segment, safely dissociating the normal ureteral tissues above and below the stricture segment, and accurately cutting off the ureteral scar are critical to ensuring low-tension anastomosis of the ureter. They are also the difficult parts of the procedure [13].

In order to accurately determine the location of the ureteral stenosis, numerous scholars have tried different methods. Kim et al. [14] used indocyanine green near-infrared fluorescence imaging to accurately locate the narrow segment of the ureter; however, the indocyanine green dye may cause side damage to the ureter. Verbeek et al. [15] used low-dose methylene blue near-infrared fluorescence to guide the identification of ureteral stricture during surgery, however, due to the complexity of these methods, they have not been effectively promoted. There are also reports of scholars using flexible ureteroscopy to locate the ureteral stenosis during surgery, then using robot-assisted laparoscopy to treat lower ureteral stenosis, achieving good results [16,17,18].

In this study, we carried out laparoscopic ureteroplasty with the aid of a ureteroscope in the lithotomy position (head high and foot low), achieving good therapeutic results. We found during the surgery that freeing the dilated ureter above the stricture was relatively easier, but the ureter at and below the stricture often faced issues due to complications of previous surgeries, including intense inflammation, dense fibrotic scar tissue surrounding the ureter, and loss of normal anatomical structures, making the freeing process difficult [19,

Conclusion

In conclusion, ureteroscopy-assisted laparoscopic ureteroplasty for ureteral stenosis after pelvic surgery is a safe and effective surgical method with certain clinical applications.