Richard Beddingfield, MS2Mentor: Manoj Monga, MD

Department of Urologic SurgeryUniversity of Minnesota

What is a ureteral stent?

Ureteral Stents. St. John Health. 19 Apr. 2006<http://www.stjohn.org/HealthInfoLib/swArticle.aspx?3,83047>

Why use a ureteral stent?Restore flow of urine in obstructed ureters (by a kidney stone, e.g.)

After surgical procedures to ensure adequate flow during recovery

Long-term drainage in patients with strictures or tumors

Help the ureter heal after an accidental perforation

Ureteral stent discomfort is common and debilitating

Pain occurs mostly in the bladder and kidney

Stent-related pain (80%)Urinary symptoms (78%)Reduced work capacity (58%)Sexual dysfunction (32%)Flank pain (25%)Irritative bladder symptoms (19%)Hematuria (18%)Bacteriuria (15%)Fever (12%)

• Damiano, R, et al: Urol Int, 69: 136, 2002• Joshi, H.B., et al: J Urol, 169: 1060, 2003

What causes ureteral stent discomfort?

Smooth muscle tone in the transmural ureter may impact bladder discomfort

• Candela, J.V., et al: J. Endourol. 11(1), 1997• Cormio, L., et al: J. Urol. 153, 1995

What causes ureteral stent discomfort?• Increased pressures in the bladder during voiding cause

reflux pain in the kidney

• Candela, J.V., et al: J. Endourol. 11(1), 1997• Cormio, L., et al: J. Urol. 153, 1995

What causes ureteral stent discomfort?• Distal portion of the ureteral stent irritates the bladder,

further increasing pain and discomfort

• Candela, J.V., et al: J. Endourol. 11(1), 1997• Cormio, L., et al: J. Urol. 153, 1995

Designing stents to reduce painIn recent years manufacturers have developed new stent materials and coatings to reduce painHydrophilic coatings decrease frictionMesh stents reduce exposed surface areaDrug-coated stents reduce encrustation and biofilm formation

None of the above designs has fullyresolved ureteral stent pain

Chew, B.H., et al: Current Opinion in Urology, 14(2): 111-115, March 2004.

Role of alpha-1 antagonists Alfuzosin (Uroxatral) is an alpha-1 blocker currently used to treat symptoms of BPHAlfuzosin relaxes smooth muscles of the lower ureter, prostatic urethra (in men), and trigone of the bladderThis helps reduce bladder pressure and resulting stent-related discomfortRecent study found less renal colic during stone passage with the use of tamsulosin compared to placebo

• Dellabella M: J Urol. Dec 2003; 170(6 Pt 1):2202-5.

Study designProspective, randomized, double-blindplacebo controlled parallel groupclinical trial

80 subjects randomized into 2 arms:alfuzosin vs. placebo

Subjects are adults undergoing unilateral retrograde ureteroscopy with stent replacement

Study designSubjects recruited from among Dr. Monga’s patientsat the University of Minnesota Kidney Stone Clinic

Patients given either alfuzosin (10mg) or placebo after surgery

Instructed to take one pill daily for 10 days or unil stent is removed

Baseline patient information recorded at consent

Ease of surgical procedure and complications recorded

Patients given standardized USSQ survey before and after stent is in place

Patients given daily drug log to record use of analgesics and narcotics

Ureteric Stent Symptom Questionnaire (USSQ)

Created and validated in 2002 by H.B. Joshi, et al, to evaluate and quantify ureteric stent pain in patients

50 questions in 6 sections:

Subjects were asked to complete the USSQ before the procedure and on day 2 following the procedure

Joshi, H.B., et al: Urology, 59: 511, 2002.

Urinary SymptomsBody PainGeneral Health

Work PerformanceSexual MattersAdditional Problems

Goals of the studyPrimary endpoint: Effect of studymedication on relief of bladder andflank pain 2 days after procedure

Secondary endpoint: Effect of study medication on urinary symptoms and quality of life following procedure

Use of analgesics and narcotics compared in alfuozsin vs. placebo groups

Where are we now?65 patients consented

9 patients dropped or excluded

3 waiting for surgery

Data not yet entered for 15 recently completed patients

Preliminary results based on 38 patients…

Preliminary resultsEarly data shows alfuzosin subjects were less likely to…

have kidney pain in the back/flank area (p=0.04)have interrupted sleep due to kidney pain (p=0.04)experience pain or discomfort while passing urine (p=0.01)urinate excessively at night (p=0.09)frequently require painkillers to control kidney pain (p=0.04)have kidney pain interfere with personal life (p=0.02)be dissatisfied with their sex lives (p=0.11)

p-values calculated using a 2-tailed, unpaired t-test comparing values of alfuzosin vs. placebo arms per single continuous variables

Preliminary resultsUSSQ P3IV: Rate on a scale of 0-10 the pain or discomfort in relation to your kidney problem in the kidney back (loin) area.

Preliminary resultsUSSQ P7: Do you experience pain or discomfort in the kidney area, while passing urine?

Initial conclusionsLess frequent urination due to decreased resistance to outflow

Alfuzosin relaxes smooth muscles in the bladder trigone and, in men, the prostatic urethraThis allows more productive—and thus less frequent—voiding

Initial conclusionsReduced kidney pain due to lower voiding pressures

Relaxation of the bladder trigone, distal ureter, and (in men) prostatic urethra reduces reflux of urine back into the kidneyLess pressure on the renal pelvis means less kidney pain

Future workContinue to consent patients

Collect all remaining patient surveys,pill bottles, and other data

Standardize daily drug logs by converting all narcotics to meqs of morphine

Perform statistical analysis on complete data set

Interpret and publish results!

AcknowledgmentsManoj Monga, MDRenato Pedro, MDBryan HinckTim Holden, MS2Kishore TA, MDJoseph Akornor, MD