Kantonsspital Baden AG, Department of Urology
Baden, Canton of Aargau, 5404, Switzerland
Not Yet Recruiting
NCT Number: NCT07618221
Air vs. Liquid: A Study on Cystoscopy Performance and Visibility Enhancement in Macrohematuria Cases
Macroscopic haematuria is a common urological emergency. Diagnostic cystoscopy is the gold standard for identifying the bleeding source; however, blood and clots within the bladder significantly impair endoscopic visibility when saline is used as the distension medium.
Air-based cystoscopy, a technique first described in the 19th century, exploits the immiscibility of gas and blood to maintain clear visualisation even during active bleeding. Despite its theoretical advantages, no randomised clinical data exist to support its use.
AIROSCOPY is a prospective, randomised, controlled, single-centre superiority study comparing air-based versus saline-based flexible cystoscopy in patients with macroscopic haematuria (Grade III-V). Patients are randomised 1:1. Only the index cystoscopy (first randomised modality) contributes to all study endpoints. A second cystoscopy with the alternative modality is performed solely for patient safety to ensure no diagnostic disadvantage from study participation. This second examination is not analysed.
The primary endpoint is identification of the bleeding source during the index cystoscopy (binary: yes/no). Secondary endpoints include time to source identification, total procedure duration, urologist-rated visibility (Likert scale), and patient comfort (Likert scale).
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Trial opening soon.
Get NotifiedKey information
Conditions
Age range
18 year and older
Sex eligibility
All sexes
Study type
Interventional
Phase
Not applicable
Primary location
About this study
Background: Continuous bladder irrigation (CBI) is the current standard management for haematuria, but can delay diagnostic cystoscopy. Gas-based cystoscopy may allow earlier and clearer visualisation of the bladder mucosa.
Design: Prospective, randomised (1:1), controlled, parallel-group, open-label, single-centre superiority trial. Randomisation is stratified by haematuria grade and history of transurethral resection (TUR-B/P), using REDCap.
Intervention: Index cystoscopy with either air (up to 240 ml by syringe) or saline (up to 240 ml by syringe), according to randomisation. A second cystoscopy with the alternative medium follows immediately, exclusively to ensure no diagnostic disadvantage for the patient (results not analysed).
Sample size: N=40 (20 per arm), based on detection rates of 86% (air) vs. 38% (saline), two-sided α=0.05, 80% power, with 20% attrition allowance.
Statistics: Chi-square test (Fisher's exact test) for the primary endpoint; risk ratio and risk difference with 95% CI reported.
Who can participate
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
- Persistent macroscopic haematuria Grade III-V within 48 hours after hospitalisation
- Age ≥ 18 years
- Unexplained macroscopic haematuria requiring diagnostic cystoscopy
- Ability to give written informed consent
Exclusion criteria
- Pregnant or lactating women
- Haemodynamic instability or urgent need for operative or interventional cystoscopy (requiring cystoscopy within < 24 hours of screening)
- Ureteral stent in situ
- Active urinary tract infection
- Transurethral resection of the bladder (TURB) or prostate (TURP) within the last 6 weeks
Treatment and study plan
Air-based flexible cystoscopy
ProcedureFlexible cystoscopy with manual air insufflation (up to 240 ml) via bladder syringe for bladder distension and visualisation.
Saline-based flexible cystoscopy
ProcedureFlexible cystoscopy with manual saline irrigation (up to 240 ml, 0.9% NaCl) via bladder syringe for bladder distension and visualisation.
Primary outcomes
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Identification of the underlying cause of macroscopic haematuria during the index cystoscopy
Time frame: Immediately after completion of the index cystoscopy (intraoperative)
Binary outcome (yes/no). Assessed in real time by the operating urologist during the index procedure and documented immediately after completion. 'Yes' if a specific bleeding source (e.g., tumour, prostate bleeding, stone, vascular lesion) is identified; 'No' otherwise.
Secondary outcomes
-
Time to source identification
Time frame: Intraoperative
Minutes from insertion of the cystoscope to first identification of the bleeding source during the index cystoscopy.
-
Total procedure duration
Time frame: Intraoperative
Minutes from insertion to removal of the cystoscope during the index cystoscopy.
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Urologist-rated visibility
Time frame: Immediately after index cystoscopy
5-point Likert scale (1 = very poor to 5 = excellent), completed by the operating urologist immediately after the index cystoscopy.
-
Patient comfort
Time frame: Immediately after index cystoscopy
Description: 5-point Likert scale (1 = very uncomfortable to 5 = very comfortable), completed by the patient immediately after the index cystoscopy.
Study contacts
Contact information is provided by the study sponsor or research team.
Sponsors and collaborators
Lead sponsor
Kantonsspital Baden
Other
Registry information
Official study title
AIROSCOPY - A Prospective, Randomized, Controlled, Single-Centre Superiority Study Comparing Air-Based Versus Saline-Based Flexible Cystoscopy for the Identification of the Bleeding Source in Patients With Macroscopic Haematuria
Acronym: AIROSCOPY
Important dates
- Study start
- 2026
- Primary completion
- 2028
- Study completion
- 2028
- First posted
- Jun 1, 2026
- Registry last updated
- Jun 3, 2026
OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.
View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.