Single-use cystoscopes mitigate several limitations of reusable cystoscopes, including high manufacturing and repair cost, requirement for skilled personnel for cleaning and processing, environmental impact of cleaning chemicals and risk of cross-contamination since it is delivered sterile. In this study we evaluate the application of the single-use Ambu® aScope™ 4 Cysto in flexible cystoscopies and patient experience in direct visualization of the urethra and bladder.

This prospective, multinational, multicentre, open-label single-arm clinical investigation included 81 adult patients undergoing cystoscopy for examination/surveillance (diagnostic group) or with endoscopic accessories for therapeutic purposes (therapeutic group). All patients were treated with Ambu® aScope™ 4 Cysto, and were divided into two cohorts, with the intent of having 40 patients in each, either undergoing flexible diagnostic cystoscopy or flexible therapeutic cystoscopy with endoscopic accessories (biopsy forceps, stent removal forceps or botulinum needles). The Ambu® aScope™ 4 Cysto can be used with endoscopic accessories. In the early stages of the trial, the displaying unit aView™ Urologia was used, but this was soon replaced by the upgraded displaying unit Ambu® aView™ 2 Advance. Four urologists with experience up to 25 years performed the examinations. Excluded were patients with a history of bladder cancer, active urinary tract infection, prior reconstructive surgery of bladder and/or urethra or an unpassable urethral stricture. The primary objective was to evaluate the performance for direct visualization and treatment of urethra and bladder. The primary endpoint was the rate of completion of procedures in patients undergoing outpatient diagnostic and therapeutic flexible cystoscopy.
The secondary objectives were to evaluate patient tolerance to the procedure and the procedural time. The secondary endpoints included i) assessment of overall performance ii) procedure time iii) patient tolerance to the procedure and iv) adverse events evaluated during the procedure and 7 days post procedure at FU call/visit. All endpoints were qualitative assessments compared to the investigator’s memory of use of their standard reusable scopes (Olympus Model: V2 or Karl Storz Model). 
A total of 80 patients were included to give an acceptable precision of the confidence interval for binary variables. As planned in the investigation protocol, all treated patients were included in all statistical analyses. The secondary efficacy objectives were analysed using data from the primary efficacy analysis set only. The investigation acceptance criteria were ≥90% of procedures completed without conversion to a reusable flexible cystoscope. StatXact, version 11.1.0 was used for calculation of p-values, and Excel for descriptive statistics. Wilcoxon rank sum test 2-sided was used, and p-value  0.05 was considered statistically significant.

The investigation sample comprised 35 males (43%) and 46 females (57%) with a mean age of 62.00 years and 61.89 years, respectively. Ambu® aScope™ 4 Cysto cystoscopy was successful in 79/81 (98%; 95% CI: 94–100) procedures. Two procedures were converted to a reusable cystoscope due to poor vision. In one of these patients, converting did not help in completing the procedure. Bleeding during insertion of the cystoscope was reported in 2/81 cases (2%), whereas, during removal, no injuries, bleedings, or damage to the cystoscope were reported. Figure 1 summarizes performance ratings for Ambu® aScope™ 4 Cysto with and without accessories. Overall, insertion, manoeuvrability, irrigation and removal were mostly scored acceptable to very easy in both diagnostic and therapeutic procedures by the investigators. The mean procedure time was 3.37 ± 0.90 minutes for diagnostic cystoscopies and 9.84 ± 3.79 minutes for therapeutic cystoscopies. These are consistent with the mean procedure times for most routine cystoscopy procedures. At 7-day Follow up (FU), pain when urinating was reported as no pain or mild pain by 88% of the patients. Increased frequency of urination during day and night post-cystoscopy was less than reported using other cystoscopes.[1] 10% of the patients reported increase in urination frequency during the day and 9% reported increase in urination frequency during the night. Three out of the six reported AEs were possibly related to the procedure (two cases of UTI and one case of a small scratch during insertion of the cystoscope causing erythema and soreness). All three adverse events are general risks in cystoscopy procedures, and one was reported to be serious due to hospitalization as the patient needed intravenous antibiotics.

In the two patients (2%) where a complete examination could not be performed with the Ambu® aScope™ 4 Cysto, decreased vision was the reason, and the cystoscope was replaced with a reusable cystoscope. In one patient, changing to a reusable scope did not provide a better vision than Ambu® aScope™ 4 Cysto. The other patient had haematuria and a tumour was suspected, which was confirmed with the reusable scope. Both patients had the initial procedure done using the displaying unit aView™ Urologia. Bladder perforation has been reported after use of biopsy instruments and after resection with electrocautery equipment. The reported incidence of bladder perforation is 0.9%–5%. In our investigation no perforation was reported. Literature [2] suggests that nearly half of the patient population undergoing flexible cystoscopy have reported post-procedural dysuria (pain and/or discomfort during urination). In our investigation, the mean pain level when urinating was 1.60 (±1.59) and the burning feeling was 1.96 (±1.55) on 5-point Likert scale.
This investigation has some limitations. With a total number of 81 patients, the risk of not observing rare adverse events is present and the opportunity to generalize from study results to a broad patient population is not possible. In general, there was no significant difference in the visualization with aView Urologia and Ambu® aView™ 2 Advance displaying unit. Nevertheless, more attempts were needed to visualize the right and left ureteral orifice of the bladder, when using the aView™ Urologia. Furthermore poor/bad light/vision was only reported for aView™ Urologia and not for Ambu® aView™ 2 Advance. The environmental impact of single-use cystoscopes has never been examined or compared to the environmental impact of reusable cystoscopes. Thus, the carbon footprint of single-use cystoscopes such as Ambu® aScope™ 4 Cysto may cause concern. When comparing the environmental impact, waste generated from using a single-use cystoscope should be compared to resources associated with routine reprocessing (e.g., personal protection equipment, electricity use, repackaging etc.) and repair of reusable cystoscopes. The carbon footprint of single-use ureteroscopes was comparable to the carbon footprint of reusable ureteroscopes.[3]

The Ambu® aScope™ 4 Cysto was found to perform well for the diagnostic and therapeutic procedures assessed. Results indicate that the risk for complication was low and pain levels were comparable with results for reusable cystoscopes based on existing literature. At 7 days FU, patients appear to experience less pain during urination. Increase in urination frequency during day and night was less than reported in literature.

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Davis NF, McGrath S, Quinlan M, et al. Carbon footprint in flexible ureteroscopy: a comparative study on the environmental impact of reusable and single-use ureteroscopes. J Endourol. 2018;32 (3):214–217.