Evaluation of Pain Before and After Removal of Non-obstructive Kidney Stones

Research Protocol

• Title of research project: Evaluation of pain before and after removal of non-obstructing renal calculi.
• Identification of Principal Investigator: Dr. Naeem Bhojani
• Multicentric study

Rationale & background information Renal stone disease is a common condition representing a lifetime occurrence risk of 10% in men and 7% in women. Renal stone disease is a chronic condition with a high recurrence rate. Additionally, renal stone disease is associated with considerable morbidity including pain. Pain associated with renal stone disease is typically caused by an obstructing stone that obstructs the flow of urine, which results in renal collecting system dilatation. This increases the intraluminal pressure of the urinary collecting system and stretches nerve ending in the ureteral mucosa and renal capsule. Non-obstructing renal calculi that do not cause renal collecting system dilatation are thought to be painless. There is however, some evidence that non-obstructing renal calculi located within the renal calyces actually do cause pain. In a small (n=13) retrospective study, it was found that ureteroscopic removal of non-obstructing renal calyceal stones achieved complete or partial resolution of pain in all patients. The reason for this pain is unknown.

Objective and hypothesis Objective To prospectively determine if the removal of non-obstructing renal calculi can reduce or eliminate participant's pain and/or improve their quality of life.

Hypothesis We hypothesize that the removal of non-obstructing renal calculi will decrease or eliminate the participant's pain and will improve their quality of life.