Bladder CancerRETRIEVE-BTNCT07762820
REtrieval of Transurethrally Resected Intact En-bloc Vesical Tumors Using a Retrieval Device for Bladder Tumors
A study testing CURTIS retrieval device in people with Bladder Cancer and Bladder Cancer TNM Staging Primary Tumor (T) T1, run by Ludwig-Maximilians - University of Munich at 9 sites in 3 countries.
Trial summary
Bladder cancer is the most common malignancy of the urinary tract, and approximately 75% of cases are non-muscle invasive (NMIBC) at diagnosis. The standard treatment is transurethral resection of the bladder tumor (TURBT). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Bladder Cancer, Bladder Cancer TNM Staging Primary Tumor (T) T1
- What is being tested?
- CURTIS retrieval device
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 9 sitesin 3 countries
- Study dates
- 1 Sep 2026to 31 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥18 years at the time of enrollment
- Suspected primary non-muscle invasive bladder cancer (NMIBC; stage pTa or pT1) based on cystoscopic assessment, with no radiological or clinical evidence of muscle-invasive disease
- Solitary or multiple bladder tumors with an estimated largest diameter of ≤50 mm based on flexible or rigid cystoscopic assessment (or cross-sectional imaging if available)
- Clinical indication for elective transurethral resection of the bladder tumor, planned to be performed as en-bloc resection
- Written informed consent obtained prior to any study-related procedure
- Ability to understand the study procedures and willingness to comply with study requirements
Who cannot join
- Known or clinically suspected muscle-invasive bladder cancer (MIBC; cT2 or higher) based on cystoscopy or imaging
- Recurrent bladder tumor (prior history of bladder tumor resection within the past 24 months)
- Active untreated urinary tract infection at the time of surgery (requiring postponement and re-evaluation)
- Uncorrectable coagulopathy or anticoagulation that cannot be safely paused perioperatively
- Severe urethral stricture precluding standard resectoscope passage
- Inability to provide written informed consent (e.g., due to cognitive impairment or language barrier without translation support)
Trial locations and contacts
9 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
9 sites in 3 countries
Germany6 sites
Urologie, Universitätsklinikum Augsburg
Augsburg, Bavaria, 86156
Roman Mayr, M.D., Prof., roman.mayr@uk-augsburg.de
Universtitätsklinikum Erlangen
Erlangen, Bavaria, 91504
Christian Fiebig, M.D., Christian.Fiebig@uk-erlangen.de
Urologie, Barmherzige Brüder Krankenhaus München
Munich, Bavaria, 80639
Alexander Prof. Karl, M.D., Prof., Alexander.Karl@barmherzige-muenchen.de
Theresa Kahl, M.D.
Urologische Klinik und Poliklinik, LMU Klinikum
Munich, Bavaria, 81377
Yannic Volz, M.D., yannic.volz@med.uni-muenchen.de
Urologische Klinik, Klinikum Rechts der Isar
Munich, Bavaria, 81675
Michael Straub, M.D., michael.straub@tum.de
Fabian Horné, M.D.
Klinik für Urologie, Klinikum Nürnberg, Campus Nord
Nuremberg, Bavaria, 90419
Gloria Zeitler, M.D., Gloria.Zeitler@klinikum-nuernberg.de
Denmark2 sites
Department of Urology, Aarhus University Hospital, Aarhus
Aarhus, 8200
Pernille S Kingo, pernking@rm.dk
Zealand University Hospital, Roskilde
Roskilde, 4000
Juan L. Vasquez, julv@regionsjaelland.dk
Greenland1 site
Department of Surgery, Queen Ingrid's Hospital
Nuuk, 3900
Jørgen B Jensen, jb@skejby.net
About this study
Official title: REtrieval of Transurethrally Resected Intact En-bloc Vesical Tumors Using a Retrieval Device for Bladder Tumors - A Prospective Multicenter Feasibility Study
Bladder cancer is the most common malignancy of the urinary tract, and approximately 75% of cases are non-muscle invasive (NMIBC) at diagnosis. The standard treatment is transurethral resection of the bladder tumor (TURBT). En bloc resection (EBR-T), in which the tumor is removed in one intact piece rather than fragmented, offers superior pathological specimen quality and may reduce the need for repeat resections. However, extracting the intact specimen from the bladder through the urethra remains a critical technical challenge, particularly for larger tumors.
CURTIS (Urotech GmbH) is a CE-marked retrieval device consisting of a hydrophilic-coated bag that can be opened and closed via a handpiece, enabling controlled capture and safe transurethral extraction of the resected tumor specimen.
This study aims to evaluate the technical feasibility of CURTIS-assisted intact specimen retrieval following en bloc transurethral resection of primary NMIBC. The central question the study seeks to answer is: in what proportion of cases can CURTIS successfully retrieve an intact en bloc resected bladder tumor, and what is the maximum tumor size for which intact retrieval remains feasible?
Read the detailed description
Here is the Detailed Description for ClinicalTrials.gov:
Study Design The RETRIEVE-BT Trial is a prospective, multicenter, single-arm, non-randomized feasibility study conducted at multiple urological centers. No control group or randomization is applied, as the study is designed to characterize the technical performance of the CURTIS device under real-world clinical conditions rather than to test a comparative efficacy hypothesis.
The CURTIS Device CURTIS (Urotech GmbH, Achenmühle, Germany) is a CE-marked medical device specifically developed for transurethral retrieval of intact bladder tumor specimens following en bloc resection. The device consists of a hydrophilic-coated retrieval bag that can be opened and closed via a handpiece, enabling controlled capture and safe transurethral extraction of the resected specimen. It is used within its approved intended purpose as defined by EU MDR 2017/745.
Surgical Procedure All procedures are performed under general or spinal anesthesia. En bloc transurethral resection is carried out using a standard resectoscope with an appropriate electrode (e.g., bipolar hook, J-electrode, or needle electrode). A circumferential incision is made in healthy urothelium approximately 3-5 mm lateral to the visible tumor margin, followed by en bloc dissection at the submucosal or muscularis propria level. Once the specimen is fully detached from the bladder wall, CURTIS-assisted retrieval is attempted according to the manufacturer's instructions for use. If retrieval with CURTIS is unsuccessful, conversion to an alternative extraction method is performed at the surgeon's discretion and documented.
Data Collection and Follow-up Data are collected prospectively via an electronic Case Report Form (eCRF). Intraoperative variables recorded include retrieval success or failure, reason for failure if applicable, total procedure time, and dedicated retrieval time. Resected specimens are processed by the local pathology department according to institutional standards; pathological variables include specimen dimensions, muscularis propria presence, pathological T-stage, histological grade (WHO 2022), and resection margin status. Postoperative complications are documented according to the Clavien-Dindo classification until hospital discharge. No additional study-specific outpatient follow-up visits are required.
Statistical Approach This is a pilot feasibility study; the statistical approach is primarily descriptive. The primary endpoint will be reported as an observed proportion with exact 95% Clopper-Pearson confidence interval. A predefined technical feasibility rate of ≥80% is the threshold indicating clinical utility. Secondary endpoints will be analyzed descriptively. A threshold analysis will be applied to identify the maximum tumor size associated with successful intact retrieval.
- Being tested
- CURTIS retrieval device
- Keywords
- bladder cancer, urothelial cell cancer, en-bloc, retrieval, transurethral resection of bladder tumor, TUR-BT
- Medical subject headings
- Urinary Bladder Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CURTIS retrieval deviceDevice
After successful en-bloc resection, the tumor is retrieved using the novel retrieval device, where the tumor is catched with a bag and removed through the urethra
| Study group | Role | What they receive |
|---|---|---|
| En-Bloc Retriever Arm | Experimental | En-bloc resection and retrieval of the tumor with CURTIS device Receives: Device: CURTIS retrieval device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Technical Feasibility Rate of CURTIS-Assisted Intact Specimen Retrieval
Proportion of enrolled patients in whom the CURTIS device enables complete, intact retrieval of the en-bloc resected bladder tumor specimen without fragmentation within the bladder or urethra. A case is classified as a technical success if the entire resected specimen is extracted through the urethra in one piece using the CURTIS device. Cases requiring conversion to an alternative retrieval method (e.g., piecemeal extraction, Ellik evacuator, endoscopic bag) are classified as technical failures.
Measured: Intraoperatively (single assessment at the time of specimen retrieval during the index surgical procedure)
Secondary outcomes (8)
Maximum Retrievable Tumor Size
Largest tumor diameter (in mm) at which successful intact retrieval using CURTIS was achieved, used to define a clinically meaningful upper size limit for CURTIS-assisted EBR-T.
Measured: Intraoperatively (measured at time of specimen retrieval)
Proportion of Specimens Containing Muscularis Propria (Detrusor Muscle)
Proportion of retrieved specimens containing detrusor muscle on pathological examination.
Measured: Perioperative/Periprocedural
Proportion of Specimens Permitting Complete Pathological T-Stage Assessment
Proportion of retrieved specimens allowing complete pathological T-stage assessment (pTa/pT1/pT2+).
Measured: Perioperative/Periprocedural
Proportion of Specimens Permitting Histological Grading
Proportion of retrieved specimens permitting grading according to WHO 2022 classification.
Measured: Perioperative/Periprocedural
Proportion of Specimens Permitting Resection Margin Assessment
Proportion of retrieved specimens permitting assessment of horizontal and vertical resection margin status.
Measured: Perioperative/Periprocedural
Total Procedure Time
Time from cystoscope insertion to complete specimen extraction and withdrawal of all instruments.
Measured: Intraoperatively (during the index surgical procedure)
Retrieval Time
Time from completion of en-bloc resection (detachment of tumor from bladder wall) to complete specimen extraction through the urethra.
Measured: Intraoperatively (during the index surgical procedure)
Perioperative Complication Rate (Clavien-Dindo Classification)
All intraoperative and postoperative complications occurring from the start of the procedure until hospital discharge, up to 30 postoperative days, classified according to the Clavien-Dindo classification system.
Measured: From start of procedure until hospital discharge, up to 30 days postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Aug 2026
- Study start1 Sep 2026 (estimated)
- Primary completion30 Dec 2026 (estimated)
- Study completion31 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bladder CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ludwig-Maximilians - University of Munich
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Yannic Volz, Ludwig-Maximilians - University of Munich
- Investigators
- Yannic T Volz, M.D., Principal investigator, Urologische Klinik und Poliklinik, LMU Klinikum München
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07762820
- Sponsor's protocol ID
- 26-0559
- Acronym
- RETRIEVE-BT
- Status last verified
- Aug 2026
- First submitted
- 7 Aug 2026
- Last updated
- 17 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Not able due to ethical and legal obligations
Study at a glance
From the registry record, last updated by the sponsor on 17 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- REtrieval of Transurethrally Resected Intact En-bloc Vesical Tumors Using a Retrieval Device for Bladder Tumors - A Prospective Multicenter Feasibility Study
- ClinicalTrials.gov ID
- NCT07762820
- Acronym / sponsor ID
- RETRIEVE-BT / 26-0559
- Keywords
- bladder cancer, urothelial cell cancer, en-bloc, retrieval, transurethral resection of bladder tumor, TUR-BT
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- Ludwig-Maximilians - University of MunichUniversity, hospital or other
- Study start
- 1 Sep 2026 (estimated)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 31 Mar 2027 (estimated)
- First posted
- 13 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Bladder cancer is the most common malignancy of the urinary tract, and approximately 75% of cases are non-muscle invasive (NMIBC) at diagnosis. The standard treatment is transurethral resection of the bladder tumor (TURBT). En bloc resection (EBR-T), in which the tumor is removed in one intact piece rather than fragmented, offers superior pathological specimen quality and may reduce the need for repeat resections. However, extracting the intact specimen from the bladder through the urethra remains a critical technical challenge, particularly for larger tumors.
CURTIS (Urotech GmbH) is a CE-marked retrieval device consisting of a hydrophilic-coated bag that can be opened and closed via a handpiece, enabling controlled capture and safe transurethral extraction of the resected tumor specimen.
This study aims to evaluate the technical feasibility of CURTIS-assisted intact specimen retrieval following en bloc transurethral resection of primary NMIBC. The central question the study seeks to answer is: in what proportion of cases can CURTIS successfully retrieve an intact en bloc resected bladder tumor, and what is the maximum tumor size for which intact retrieval remains feasible?
Detailed description
Here is the Detailed Description for ClinicalTrials.gov:
Study Design The RETRIEVE-BT Trial is a prospective, multicenter, single-arm, non-randomized feasibility study conducted at multiple urological centers. No control group or randomization is applied, as the study is designed to characterize the technical performance of the CURTIS device under real-world clinical conditions rather than to test a comparative efficacy hypothesis.
The CURTIS Device CURTIS (Urotech GmbH, Achenmühle, Germany) is a CE-marked medical device specifically developed for transurethral retrieval of intact bladder tumor specimens following en bloc resection. The device consists of a hydrophilic-coated retrieval bag that can be opened and closed via a handpiece, enabling controlled capture and safe transurethral extraction of the resected specimen. It is used within its approved intended purpose as defined by EU MDR 2017/745.
Surgical Procedure All procedures are performed under general or spinal anesthesia. En bloc transurethral resection is carried out using a standard resectoscope with an appropriate electrode (e.g., bipolar hook, J-electrode, or needle electrode). A circumferential incision is made in healthy urothelium approximately 3-5 mm lateral to the visible tumor margin, followed by en bloc dissection at the submucosal or muscularis propria level. Once the specimen is fully detached from the bladder wall, CURTIS-assisted retrieval is attempted according to the manufacturer's instructions for use. If retrieval with CURTIS is unsuccessful, conversion to an alternative extraction method is performed at the surgeon's discretion and documented.
Data Collection and Follow-up Data are collected prospectively via an electronic Case Report Form (eCRF). Intraoperative variables recorded include retrieval success or failure, reason for failure if applicable, total procedure time, and dedicated retrieval time. Resected specimens are processed by the local pathology department according to institutional standards; pathological variables include specimen dimensions, muscularis propria presence, pathological T-stage, histological grade (WHO 2022), and resection margin status. Postoperative complications are documented according to the Clavien-Dindo classification until hospital discharge. No additional study-specific outpatient follow-up visits are required.
Statistical Approach This is a pilot feasibility study; the statistical approach is primarily descriptive. The primary endpoint will be reported as an observed proportion with exact 95% Clopper-Pearson confidence interval. A predefined technical feasibility rate of ≥80% is the threshold indicating clinical utility. Secondary endpoints will be analyzed descriptively. A threshold analysis will be applied to identify the maximum tumor size associated with successful intact retrieval.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| En-Bloc Retriever Arm | Experimental | Device: CURTIS retrieval deviceEn-bloc resection and retrieval of the tumor with CURTIS device |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥18 years at the time of enrollment
- Suspected primary non-muscle invasive bladder cancer (NMIBC; stage pTa or pT1) based on cystoscopic assessment, with no radiological or clinical evidence of muscle-invasive disease
- Solitary or multiple bladder tumors with an estimated largest diameter of ≤50 mm based on flexible or rigid cystoscopic assessment (or cross-sectional imaging if available)
- Clinical indication for elective transurethral resection of the bladder tumor, planned to be performed as en-bloc resection
- Written informed consent obtained prior to any study-related procedure
Key exclusion criteria (6 listed)
- Known or clinically suspected muscle-invasive bladder cancer (MIBC; cT2 or higher) based on cystoscopy or imaging
- Recurrent bladder tumor (prior history of bladder tumor resection within the past 24 months)
- Active untreated urinary tract infection at the time of surgery (requiring postponement and re-evaluation)
- Uncorrectable coagulopathy or anticoagulation that cannot be safely paused perioperatively
- Severe urethral stricture precluding standard resectoscope passage
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CURTIS retrieval deviceAfter successful en-bloc resection, the tumor is retrieved using the novel retrieval device, where the tumor is catched with a bag and removed through the urethra | Device | En-Bloc Retriever Arm |
Primary outcome
Technical Feasibility Rate of CURTIS-Assisted Intact Specimen Retrieval
Time frame: Intraoperatively (single assessment at the time of specimen retrieval during the index surgical procedure)
Proportion of enrolled patients in whom the CURTIS device enables complete, intact retrieval of the en-bloc resected bladder tumor specimen without fragmentation within the bladder or urethra. A case is classified as a technical success if the entire resected specimen is extracted through the urethra in one piece using the CURTIS device. Cases requiring conversion to an alternative retrieval method (e.g., piecemeal extraction, Ellik evacuator, endoscopic bag) are classified as technical failures.
8 secondary outcomes
Maximum Retrievable Tumor Size
Time frame: Intraoperatively (measured at time of specimen retrieval)
Proportion of Specimens Containing Muscularis Propria (Detrusor Muscle)
Time frame: Perioperative/Periprocedural
Proportion of Specimens Permitting Complete Pathological T-Stage Assessment
Time frame: Perioperative/Periprocedural
Proportion of Specimens Permitting Histological Grading
Time frame: Perioperative/Periprocedural
Proportion of Specimens Permitting Resection Margin Assessment
Time frame: Perioperative/Periprocedural
Total Procedure Time
Time frame: Intraoperatively (during the index surgical procedure)
Retrieval Time
Time frame: Intraoperatively (during the index surgical procedure)
Perioperative Complication Rate (Clavien-Dindo Classification)
Time frame: From start of procedure until hospital discharge, up to 30 days postoperatively
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Aug 2026.
- Individual participant dataSharing planned: No. Not able due to ethical and legal obligations
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Yannic T Volz, M.D. principal investigator
Urologische Klinik und Poliklinik, LMU Klinikum München
9 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CURTIS retrieval device in people with Bladder Cancer and Bladder Cancer TNM Staging Primary Tumor (T) T1, run by Ludwig-Maximilians - University of Munich at 9 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 17 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 9 sites in Germany, Denmark, Greenland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Yannic T PD Dr. Volz, M.D. (+4989440071357, yannic.volz@med.uni-muenchen.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Technical Feasibility Rate of CURTIS-Assisted Intact Specimen Retrieval (time frame: Intraoperatively (single assessment at the time of specimen retrieval during the index surgical procedure)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Aug 2026.