Ureteroscopy

On the day of surgery, prior to the start of the operative list, patients on the list underwent a world health organisation (WHO) style checklist with the rest of theatre and recovery team, and all high-risk patients were identified with a clear post-operative plan to manage them. Identification of pre-operative antibiotics, venous thromboembolism (VTE) prophylaxis, approximate length of the proposed procedure with any anticipated difficulties were also undertaken. Any anaesthetic or surgical concerns were highlighted to the rest of the team ensuring that all necessary theatre kits and accessories for a given case were available at hand.
A standard protocol-led procedure was carried out for every patient. Under general anaesthetic, patients had an initial cystoscopy and placement of a safety guidewire. A rigid ureteroscopy (4.5F or 6F Wolf or Storz rigid ureteroscope) was then carried out up to the renal pelvis or as far proximally as was safely achievable (or to the ureteric stone), and used to advance the second guidewire into the kidney. For renal stones, if appropriate, a ureteral access sheath (9.5F/11.5F or 12F/14F Cook Flexor sheath, size determined at the time) was introduced over a second guidewire to optimise visualisation, intrarenal pressure and to facilitate extraction of large or multiple renal stones. A flexible ureteroscopy (Storz FlexX2) and laser stone fragmentation was then carried out. All stones were managed by either laser fragmentation, basket extraction or a combination of the two, with all accessible stones fragmented to 1 or 2 mm or dust and larger fragments retrieved actively with a Cook Ngage stone extractor (Cook Medical, USA). In most cases, a 6F ureteral stent was placed post-URS and this was removed via a local anaesthetic flexible cystoscopy 1–3 weeks post-procedure. Unless clinically indicated, patients did not have a routine post-operative urethral catheter insertion and were discharged home the same day.

All adults who underwent ureteroscopy (URS) procedure for stone disease over a 52-month period between March 2012 and July 2016 were included in this study. Our audit was registered with our hospital ‘Clinical Effectiveness (CE) and Audit office’ with patient consent for participation taken prior to the procedure. Outcomes were collated prospectively for consecutive adults (>18 years of age) who underwent URS for stone disease, performed or supervised by a single surgeon (BS) at our institution and recorded in our prospective database which was then analysed retrospectively by a third party (AG, RO) not involved in the original procedure. Data were collected for patient demographics, stone parameters, pre-operative assessment, operative details, length of stay (LoS), stone-free rate (SFR) and complication rates associated with the procedure. LoS was defined as the time from completion of URS to discharge of patients with day case defined as those patients discharged on the same day as having undergone the procedure. Data were recorded on excel spread sheet and analysed using SPSS version 22.

Two authors independently extracted data using a unified form developed by the authors (Table 1). Any differences were resolved by consensus. In addition, the following information was extracted from each trial: study location, year of publication, number of patients enrolled, inclusion and exclusion criteria, side effects, and distribution of outcome data.Table 1

Number of included studies and enrolled patients according to the individual interventions

Interventions	Studies (n)	Patients (n)	Operation	Published year
Ketorolac	1	65	ULS	2014
Lidocaine	1	66	TURBt	2020
Ketamine	2	82	TURBt	2016
Parecoxib	1	61	TURBt	2018
Solifenacin	1	62	TURBt	2015
Magnesium	1	60	TURBt	2020
Dexmedetomidine	2	79	TURBt	2015–2016
Chlorpheniramine	2	76	TURBt&UL	2021
Nefopam	2	63	TURBt&UL	2018–2021
Penile nerve block	2	126	TURBt&TURP	2017–2021
Gabapentin	1	50	PCNL	2018
Tolterodine	1	50	PCNL	2018
Bupivancaine	1	31	PCNL	2020
Oxycodone	1	46	TURP	2019
Hyoscine N-butyl bromide	1	24	TURP	2017
Placebo	18	875		2014–2021
Total	18	1816		2014–2021

ULS urology laparoscopic surgery, UL ureteroscopic lithotripsy, TURBt Transurethral Resection of Bladder tumors, TURP transurethral resection of prostate, PCNL percutaneous nephrolithotomy

The surgical approaches included endoscopic balloon dilatation and balloon dilatation combined with endoureterotomy (Figure 2 and Supplementary Figure S1).
The main procedure for balloon dilation is to place the balloon dilator (F18–F30) along the guide wire after passing the stricture section during percutaneous nephroscopy or ureteroscopy. Then, the balloon is placed at the stricture site under direct vision, the pump is pressurized to 15–30 atm, the balloon is filled and kept filled for 3–5 min, and the balloon dilation catheter is removed. In the cases in this study, two ureteral stents were placed.
Balloon dilation combined with endoureterotomy is primarily performed by incising the end of the ureter with electrodes and then placing a balloon dilator along the guide wire.

A total of 196 patients with ureteral stricture underwent balloon dilation between January 2012 and August 2022 at the Peking University First Hospital, Miyun Hospital, Emergency General Hospital, and Jian Gong Hospital. Baseline data and follow-up data were complete for 127 patients, including 97 patients with balloon dilation and 30 patients with balloon dilation combined with endoureterotomy (Figure 1 and Table 1). The patient’s phone number was empty and wrong, and the patient or his family members refused to follow up and lost contact. Clinical data, including general clinical data, perioperative data, balloon parameters at the time of surgery, and follow-up results, were collected in our Reconstruction of the Urinary Tract: Epidemiology and Result (RECUTTER) database [18 (link)].
Postoperative results of ureteral stenosis patients were collected at 3 months, 6 months, and 1 year after surgery, and the results of balloon dilatation treatment were evaluated at different periods and patients in each period were divided into two groups (failure group and non-failure group). One of the following conditions resulted in patients being allocated to the failure group: the reappearance of ureteral stricture and worsening of hydronephrosis on routine imaging (intravenous pyelogram, renal scan, retrograde pyelogram, ultrasound); the need for the repositioning of the DJ tube/nephrostomy tube; or surgical treatment. The remaining patients were allocated to the non-failure group.
The risk factor analysis included the following criteria: (a) patients with ureteral strictures detected through ureteroscopy or imaging. Imaging examinations include intravenous urography, computed tomography urogram, and magnetic resonance urography; (b) treatment with balloon dilation only and with technical success. Technical success is defined as the ability of the ureteroscope and guidewire to pass through the balloon-dilated ureteral stricture and successful retention of a double J ureteral stent. Exclusion criteria: (a) contraindication to surgery; (b) combined pregnancy; (c) conditions that the investigator needed to exclude; (d) incomplete data; and (e) a combined history of malignancy. The surgical outcome 3 months postoperatively was considered as the endpoint. In an analysis of risk factors for the failure of balloon dilatation alone, data from 97 patients were considered valid.
To compare the efficacy of balloon dilation versus balloon dilation combined with endoureterotomy in the treatment of lower segment ureteral stricture, patients with multi-segmental strictures were excluded.
The endpoint was clarified by a telephone follow-up, and the true validity of the clinical data was verified in 127 patients. The information collected included gender, age, BMI, preoperative renal function (preoperative creatinine, preoperative urea nitrogen, preoperative blood eGFR), ureteral stricture length, ureteral stricture site, whether there was a history of urologic surgery, balloon circumference, balloon pressure, and duration of dilation. The risk factors for recurrence after the balloon dilation of ureteral stricture were investigated according to whether the patients’ surgical outcome had failed or been successful, as of the endpoint.
A total of 127 patients with complete data after follow-up were included in this study. There were 97 patients with balloon dilatation alone and 30 patients with balloon dilatation combined with endoureterotomy. There were 67 patients with lower segment ureteral stricture, of which 30 received balloon dilatation combined with endoureterotomy and 37 received balloon dilatation alone. Among 97 patients who underwent balloon dilatation alone, 10 patients had multiple ureteral stenosis, 4 patients had middle ureteral stenosis, and 83 patients had upper and lower ureteral stenosis.
This study was designed and conducted in accordance with the principles of the Declaration of Helsinki (revised 2013) and was approved by the Ethics Committee of Peking University First Hospital. Individual consent was waived due to the retrospective nature of this study.