This is a prospective, randomized, randomized and single-blind study in patients diagnosed with primary bladder CV. Patients diagnosed by cystoscopy of a bladder tumor and with indication for endoscopic surgical treatment, who meet the inclusion criteria, and who sign the Informed Consent (IC), will be randomized.

The main objective of the study is to assess the quality of the resection, defined as the presence of detrusor muscle in the resected tissue.

The secondary objetives are:

• Compare the surgical time, hospital stay, urinary catheterization time and incidence of complications.
• Compare tumor recurrence after one year of follow up.
• Determine the number of re-TURB as a consequence of the absence of muscle layer in the sample or artifacts (Tx)
• Establish the incidence of conversions as a consequence of difficulties in the technique or intraoperative bleeding.
• Compare the degree of satisfaction of the surgeon

Inclusion Criteria:

• >18 years old.
• Polypoid / sessile primary tumor.
• < 3 tumors
• Tumor size 10 - 30 mm.

Exclusion Criteria:

• > 4 tumors
• Size of the largest tumor <1 cm and> 4 cm.
• Tumor located in the bladder dome.
• No visualization of the ureteral meatus.
• Flat or in situ tumor.
• Non-urothelial tumors.
• Clotting disorder or treatment with oral anticoagulants.