Intraureteral of Alkalinized Lidocaine as Novel Approach to Post-Ureteroscopy Pain: Double-blind Prospective Randomized Controlled Trial

Patients treated with ureteroscopy (URS) for ureteral or renal calculi requiring a ureteral stent at time of URS will be randomized to receive intraureteral instillation of alkalinized lidocaine hydrochloride (study group) or normal saline (control group) immediately following the procedure to assess safety and effectiveness in alleviating pain and stent symptoms. Thousands of removable stents are placed in patients' ureters (tubes connecting kidney and bladder) each year in Canada. These plastic stents allow the kidney to drain when there is swelling after kidney stone surgery or if they are otherwise obstructed. Studies report that more than 80% of patients have painful symptoms from indwelling ureteral stents. This study will attempt to show that local anesthetic injected directly into the ureter before stent placement will reduce stent pain. Recent studies have shown infusing lidocaine with bicarbonate (a local anesthetic) into painful bladders is safe, and patients' symptoms improve dramatically. This result inspired the innovative idea that injecting a similar solution into the kidney and ureter (which have the same lining as the bladder) will numb the area sufficiently to decrease stent related pain.

The study will randomly select half of the patients to receive an injection of non-irritating salt water (placebo), and half an injection of pH buffered lidocaine before the stent is placed. Both patients and physicians will be blinded to the assignment of treatment or placebo. The investigators will then compare pain scores post operatively.

If successful, future researchers may use lidocaine in drug eluding stents to further ameliorate pain.