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REtrieval of Transurethrally Resected Intact En-bloc Vesical Tumors Using a Retrieval Device for Bladder Tumors (RETRIEVE-BT)

13 augustus 2026 bijgewerkt door: Yannic Volz, Ludwig-Maximilians - University of Munich

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?

Studie Overzicht

Toestand

Nog niet aan het werven

Conditie

Interventie / Behandeling

Gedetailleerde beschrijving

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.

Studietype

Ingrijpend

Inschrijving (Geschat)

75

Fase

  • Niet toepasbaar

Contacten en locaties

In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.

Studiecontact

Studie Locaties

  • Denemarken
      • Aarhus, Denemarken, 8200
        • Department of Urology, Aarhus University Hospital, Aarhus
        • Contact:
      • Roskilde, Denemarken, 4000
  • Duitsland
    • Bavaria
      • Augsburg, Bavaria, Duitsland, 86156
      • Erlangen, Bavaria, Duitsland, 91504
      • Munich, Bavaria, Duitsland, 80639
      • Munich, Bavaria, Duitsland, 81377
      • Munich, Bavaria, Duitsland, 81675
        • Urologische Klinik, Klinikum Rechts der Isar
        • Contact:
        • Onderonderzoeker:
          • Fabian Horné, M.D.
      • Nuremberg, Bavaria, Duitsland, 90419
  • Groenland
      • Nuuk, Groenland, 3900
        • Department of Surgery, Queen Ingrid's Hospital
        • Contact:

Deelname Criteria

Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.

Geschiktheidscriteria

Leeftijden die in aanmerking komen voor studie

  • Volwassen
  • Oudere volwassene

Accepteert gezonde vrijwilligers

Nee

Beschrijving

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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)

Studie plan

Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.

Hoe is de studie opgezet?

Ontwerpdetails

  • Primair doel: Diagnostisch
  • Toewijzing: NVT
  • Interventioneel model: Opdracht voor een enkele groep
  • Masker: Geen (open label)

Wapens en interventies

Deelnemersgroep / Arm
Interventie / Behandeling
Experimenteel: En-Bloc Retriever Arm
En-bloc resection and retrieval of the tumor with CURTIS device
Apparaat: CURTIS retrieval device
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

Wat meet het onderzoek?

Primaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Technical Feasibility Rate of CURTIS-Assisted Intact Specimen Retrieval
Tijdsspanne: 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.
Intraoperatively (single assessment at the time of specimen retrieval during the index surgical procedure)

Secundaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Maximum Retrievable Tumor Size
Tijdsspanne: Intraoperatively (measured at time of specimen retrieval)
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.
Intraoperatively (measured at time of specimen retrieval)
Proportion of Specimens Containing Muscularis Propria (Detrusor Muscle)
Tijdsspanne: Perioperative/Periprocedural
Proportion of retrieved specimens containing detrusor muscle on pathological examination.
Perioperative/Periprocedural
Proportion of Specimens Permitting Complete Pathological T-Stage Assessment
Tijdsspanne: Perioperative/Periprocedural
Proportion of retrieved specimens allowing complete pathological T-stage assessment (pTa/pT1/pT2+).
Perioperative/Periprocedural
Proportion of Specimens Permitting Histological Grading
Tijdsspanne: Perioperative/Periprocedural
Proportion of retrieved specimens permitting grading according to WHO 2022 classification.
Perioperative/Periprocedural
Proportion of Specimens Permitting Resection Margin Assessment
Tijdsspanne: Perioperative/Periprocedural
Proportion of retrieved specimens permitting assessment of horizontal and vertical resection margin status.
Perioperative/Periprocedural
Total Procedure Time
Tijdsspanne: Intraoperatively (during the index surgical procedure)
Time from cystoscope insertion to complete specimen extraction and withdrawal of all instruments.
Intraoperatively (during the index surgical procedure)
Retrieval Time
Tijdsspanne: Intraoperatively (during the index surgical procedure)
Time from completion of en-bloc resection (detachment of tumor from bladder wall) to complete specimen extraction through the urethra.
Intraoperatively (during the index surgical procedure)
Perioperative Complication Rate (Clavien-Dindo Classification)
Tijdsspanne: From start of procedure until hospital discharge, up to 30 days postoperatively
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.
From start of procedure until hospital discharge, up to 30 days postoperatively

Medewerkers en onderzoekers

Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.

Sponsor

Ludwig-Maximilians - University of Munich

Onderzoekers

  • Hoofdonderzoeker: Yannic T Volz, M.D., Urologische Klinik und Poliklinik, LMU Klinikum München

Studie record data

Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.

Bestudeer belangrijke data

Studie start (Geschat)

1 september 2026

Primaire voltooiing (Geschat)

30 december 2026

Studie voltooiing (Geschat)

31 maart 2027

Studieregistratiedata

Eerst ingediend

7 augustus 2026

Eerst ingediend dat voldeed aan de QC-criteria

11 augustus 2026

Eerst geplaatst (Werkelijk)

13 augustus 2026

Updates van studierecords

Laatste update geplaatst (Werkelijk)

17 augustus 2026

Laatste update ingediend die voldeed aan QC-criteria

13 augustus 2026

Laatst geverifieerd

1 augustus 2026

Meer informatie

Termen gerelateerd aan deze studie

Trefwoorden

Aanvullende relevante MeSH-voorwaarden

Andere studie-ID-nummers

  • 26-0559

Plan Individuele Deelnemersgegevens (IPD)

Bent u van plan om gegevens van individuele deelnemers (IPD) te delen?

NEE

Beschrijving IPD-plan

Not able due to ethical and legal obligations

Informatie over medicijnen en apparaten, studiedocumenten

Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel

Nee

Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct

Nee

product vervaardigd in en geëxporteerd uit de V.S.

Nee

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