The Effect of Ureteric Stent Tethers on Patient Symptoms and Urinary Infection

Two of the main issues surrounding the use of ureteral stents are stent related symptoms and bacterial colonization/urinary tract infection (UTI). To be useful, stent tethers must decrease the morbidity associated with stent removal and the cost to the health care system, while not increasing stent related symptoms or UTI. To our knowledge, the effect of leaving a stent tether on stent symptoms and bacterial colonization of the stent and urine has not been previously studied.

This is a single-centre, prospective, randomized, controlled trial. Patients eligible for recruitment into the study based on the inclusion and exclusion criteria will be provided with a consent form at the time of their initial appointment, when their ureteroscopy is being booked. Once consent is obtained, patients will be randomized (using random number table look-up) to receive either double-J stent placement with a tether (the Treatment Group) or double-J stent placement without a tether (the Control Group) following ureteroscopy. Randomization will occur prior to the commencement of ureteroscopy.

Patients will either have a double J-stent placed with or without a long tether attached. The double-J stents used in the treatment and control groups will be otherwise identical. All stents will be 6 French in diameter and 22-26 cm in length based on the patients' height. Sizing of stent length will be performed uniformly in the treatment and control group and will involve measuring ureteric length from the ureteropelvic junction to ureterovesical junction with a marked ureteral catheter. All patients will receive a single preoperative dose of prophylactic antibiotics (i.e., Ampicillin and Gentamicin or Ciprofloxacin).All patients will have a urine sample collected for culture and sensitivity at the start of the procedure.

Blinding will not be feasible during this trial due to the nature of the intervention. The urologist performing the procedure will clearly be aware of whether a tether is left on the stent. Similarly, patients will also be aware of whether a string tether is protruding from their urethral meatus or not. However, assessors of the compiled data and questionnaires will be blinded to the intervention.

Once enrolled in the study, patients will be given the Ureteral Stent Symptoms Questionnaire 1 (Pre Stent) to complete prior to undergoing ureteroscopy and stent insertion. This will allow us to establish baseline lower urinary tract symptoms.

After completion of ureteroscopy and stent insertion and upon discharge from the hospital all patients will be provided with the following:

1. Diary sheets to record daily analgesic use
2. A prescription for a standardized analgesic regimen including Percocet (1 tablet PO q6h prn, 20 tablets) to be taken as needed for pain control.
3. An appointment for the first follow-up visit (in 7-14 days)

At the follow-up visit, a kidney, ureter and bladder (KUB) radiograph will be performed and patients will complete the Ureteral Stent Symptoms Questionnaire 2 (Stent insitu). The KUB x-ray will be reviewed to ensure the stent remained in appropriate position and did not migrate and that any residual stone fragments have passed. Next, all patients will have their stent removed. Patients in the control group will undergo cystoscopy under local anesthesia for stent removal and those the treatment group will have the stent removed by the tether. This distal curl or lower end (bladder) of the double-J stent, in all patients, will be sent to microbiology for culture to determine the rate of stent bacterial colonization. Of note, all patients in the control group will provide a mid-stream urine sample to be sent for culture and sensitivity testing, after cystoscopy and stent removal, while all patients in the treatment group will provide a urine sample after the stent is removed, so the tether does not contaminate the sample. This urine sample will allow us to establish the rate of bacteriuria.

Upon discharge from the Cystoscopy unit following stent removal all patients will return for a final follow-up with renal ultrasound approximately 4-6 weeks post-stent removal and will be given the Ureteral Stent Symptoms Questionnaire 3 (Post Stent) to complete.