An interventional study of Bipolar transurethral modified en bloc resection of bladder tumour in Bladder Cancer, Bladder Neoplasm and Bladder Tumor, sponsored by Chinese University of Hong Kong. Completed at 1 site in Hong Kong. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-07-22.
Sponsored by Chinese University of Hong Kong · Not applicable, Interventional, and Treatment
Modified en bloc resection is a hybrid technique involving piecemeal resection of the exophytic part of the bladder tumour, followed by en bloc resection of the tumour base. In this study, we shall investigate the efficacy of modified en bloc resection for patients with bladder tumours of ≥3cm in size.
The biggest limiting factor of en bloc resection is the size of the bladder tumour. Resection of the bladder tumour is technically feasible, but the retrieval of specimen in one piece is restricted by the narrow size of the urethra. However, the greatest advantage of en bloc resection is to ensure complete local resection rather than the theoretical benefit of avoiding tumour re-implantation. Therefore, the concept of modified en bloc resection for large bladder tumours of ≥3cm has evolved. It is a hybrid technique involving piecemeal resection of the exophytic part of the bladder tumour, followed by en bloc resection of the tumour base. By resecting the exophytic part of the bladder tumour, the size of main tumour bulk can be reduced. By performing en bloc resection of the tumour base, the advantage of ensuring complete tumour resection beneath the submucosal plane can be preserved, and the tumour base specimen remains intact for histological assessment of the resection margins. Modified en bloc resection is a promising surgical technique which can potentially ensure complete tumour resection, reduce the need of second-look transurethral resection, and improve the oncological control of non-muscle-invasive bladder cancer in long run. It may also ensure proper staging of muscle-invasive bladder cancer at the first surgery, thus avoiding the need of second-look transurethral resection in under-staged patients.
In this study, we shall evaluate the efficacy of modified en bloc resection for patients with bladder tumours of ≥3cm. All patients will have MRI before modified en bloc resection. All patients with non-muscle-invasive bladder cancer will be offered second-look transurethral resection in 2-6 weeks' time. All patients with muscle-invasive bladder cancer but not distant metastasis will be offered radical cystectomy, pelvic lymphadenectomy and urinary diversion; for those who refuse or who are considered unfit for radical surgery, second-look transurethral resection will be offered. All patients will have a second MRI before the second surgery. The modified en bloc resection specimen results will be compared with the final pathology results in the second surgery. The presence of any residual or upstaging of disease will be determined. The results of the two sets of MRI will also be compared with the final pathology results. The accuracy of MRI in the evaluation of bladder cancer will be determined.
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This study's enrollment of 30 is below the median of 60 across 1,163 interventional studies indexed under Urinary Bladder Neoplasms.
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Exclusion Criteria:
For patients undergoing modified en bloc resection, piecemeal resection of the exophytic part of the bladder tumour will be performed, followed by en bloc resection of the tumour base.
Device: Bipolar transurethral modified en bloc resection of bladder tumour
Olympus TURis Bipolar HF-resection electrode (Model: WA22306D)
Composite outcome on the rate of complete resection for non-muscle-invasive bladder cancer and proper staging for muscle-invasive bladder cancer
Complete resection for non-muscle-invasive bladder cancer is defined as the absence of any malignancy upon second-look transurethral resection surgery, in patients who have non-muscle-invasive bladder cancer upon the first modified en bloc resection. Proper staging for muscle-invasive bladder cancer is defined as the detection of muscle-invasive bladder cancer upon the first modified en bloc resection, in all patients who have a definitive histological diagnosis of muscle-invasive bladder cancer upon modified en bloc resection or second-look transurethral resection surgery. Second look transurethral resection surgery is expected to perform within six weeks after the experimental operation and one more week is allowed for histological assessment of the second look transurethral resection specimen.
Time frame: Seven weeks after the experimental operation
Proper staging rate for non-muscle-invasive bladder cancer
The proper staging rate for non-muscle-invasive bladder cancer is defined as the absence of any upstaging of the T-stage upon second-look transurethral resection surgery, in patients who have non-muscle-invasive bladder cancer upon the first modified en bloc resection. Second look transurethral resection surgery is expected to perform within six weeks after the experimental operation and one more week is allowed for histological assessment of the second look transurethral resection specimen.
Time frame: Seven weeks after the experimental operation
Complete resection rate for muscle-invasive bladder cancer
The complete resection rate for muscle-invasive bladder cancer is defined as the absence of any malignancy upon second-look transurethral resection surgery or radical surgery, in patients who have muscle-invasive bladder cancer upon the first modified en bloc resection. Second look transurethral resection surgery or radical surgery are expected to perform within six weeks after the experimental operation and one more week is allowed for histological assessment of the second look transurethral resection specimen.
Time frame: Seven weeks after the experimental operation
Successful modified en bloc resection rate
Techical success rate of modified en bloc resection
Time frame: Immediately post-operative
Negative circumferential resection margin rate
Rate of negative circumferential resection margin of the modified en bloc resection pathological specimen
Time frame: One week after the experimental operation
Negative deep resection margin rate
Rate of negative deep resection margin of the modified en bloc resection pathological specimen
Time frame: One week after the experimental operation
Detrusor muscle sampling rate
Rate of presence of detrusor muscle in the modified en bloc resection pathological specimen
Time frame: One week after the experimental operation
Occurrence of obturator reflex
Number of participants with obturator reflex encountered by the operating surgeon during the modified en bloc resection operation
Time frame: Intra-operative
Operative time
Duration of operation
Time frame: Immediately post-operative
Rate of mitomycin C instillation
One day after the experimental operation
Time frame: Immediately post-operative
Duration of bladder irrigation
Duration of bladder irrigation. Patients undergoing transurethral resection surgery have an average hospital stay of three days. Bladder irrigation is always stopped before the patient is discharged
Time frame: Three days after the experimental operation.
Duration of urethral catheterisation
Duration of urethral catheterisation. Patients undergoing transurethral resection surgery have an average hospital stay of three days. Urethral catheter is often removed before the patient is discharged
Time frame: Three days after the experimental operation
Hospital stay
Patients undergoing transurethral resection surgery have an average hospital stay of three days.
Time frame: Three days after the experimental operation
30-day complications
Complications which occur within 30 days after the operation
Time frame: Thirty days after the experimental surgery
Plan to share: No
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Chinese University of Hong Kong