Safety and Effectiveness of Ureteral DJ Stent With Magnet (Blackstar, Urotech) Removal Under Ultrasound Control

Inclusion criteria

• age from 18 to 70 years
• males
• Indications for rigid or flexible URS
• ASA score: 1-3

Exclusion criteria

• Active urinary tract infection
• taking alpha-1 adreno and M-cholinoblockers

All patients will be randomized into 2 groups:

• group A - male patients who will undergo ureteral stent placement by conventional polyurethane DJ stent, Fr 6.5. N=30
• group B - male patients who will undergo ureteral stent placement by polyurethane DJ stent with magnet (Blackstar, Urotech ), Fr 7. N=30 Patients are to be assigned a randomization number that will match their treatment. Block randomization using 10 blocks is to be performed by a central randomization organization (www.randomize.net) using a computerized algorithm.

Using the Visual Analog Scale of Pain (VASP) and Ureteric Stent Symptom Questionnaire (USSQ) we are going to assess the pain syndrome and the severity of stent-associated symptoms. The USSQ will be filled twice: 3 days after stent placement and on the day of stent removal, just before the procedure. All stents will be removed 30 days after placement. Also, immediately after stent removal, patients will complete the VASP questionnaire. In the control group, the stent will be removed using flexible cystoscopy. In the experimental group under ultrasound control using a magnetic retriever, with a bladder capacity of at least 150 ml.

Primary assessed outcomes:

• Age
• Body mass index
• Operation side
• The density of the stone
• Type of the operation
• Applying of the ureteral accessing sheath
• Type of the ureteral stent
• Troubles with stent placement
• USSQ (Ureteral stent symptom questionnaire) 3 days after surgery
• USSQ before stent extraction
• VASP (Visual Analog Scale Pain) immediately after stent extraction
• Duration of stent extractiom by magnetic retrieval device
• Duration of stent extraction by cystoscopy
• Stent removal success (yes/no)

Secondary assessed outcomes:

• Assessment of Stone-free status after surgery by performing computed tomography of kidneys and urinary tract without intravenous contrasting 1 month after surgery
• Stent encrustation

Inclusion criteria

• age from 18 to 70 years
• males
• Indications for rigid or flexible URS
• ASA score: 1-3

Exclusion criteria

• Active urinary tract infection
• taking alpha-1 adreno and M-cholinoblockers