Feasibility Study of a Randomized Controlled Trial Investigating Renal Denervation as a Possible Treatment Option in Patients With Loin Pain Hematuria Syndrome

Abstract

Background: Loin Pain Hematuria Syndrome (LPHS) is a poorly understood clinical condition characterized by severe pain localized to the kidney but in the absence of identifiable urinary tract disease. There is no consensus on optimal treatment strategies for LPHS. Case reports and series have shown renal denervation via catheter-based radiofrequency ablation to be an effective therapeutic option for the treatment of LPHS. To determine whether catheter-based renal denervation is a meaningful addition to the treatment options in these often-difficult-to-treat LPHS patients, a randomized clinical trial is needed. Prior to conducting a definitive trial that focuses on patient outcomes, ensuring the feasibility of undertaking such a trial is required. As such, we will conduct a single-center randomized control feasibility trial designed to determine viability and provide framework and direction for a larger trial. Objective: The objective of the study is to determine whether conducting a randomized trial of renal denervation versus sham procedure is feasible in terms of recruitment and eligibility, and adequacy of follow-up in LPHS patients. Design: Single-center double-blinded, parallel-group, partial crossover, sham-controlled, randomized feasibility trial of 10 LPHS patients. Setting: Regina General Hospital in Regina, Saskatchewan, Canada. Patients: Ten LPHS patients who require opioid therapy. Measurements: The main feasibility outcome measures include proportion of target patients who undergo the procedure (treatment or sham) within 6 months; proportion of randomized participants (treatment or control) who entirely complete the follow-up measures at 6 weeks, 3 and 6 months; proportion of the participants who were randomized to control group, cross over after 6 months and opt-in renal denervation treatment; proportion of the crossover participants who complete the follow-up measures at 6 weeks, 3 and 6 months. Pain will be assessed using Brief Pain Inventory Score, McGill Pain Questionnaire, and a pain diary. Mood, disability, and quality of life will be measured by Center for Epidemiologic Studies Depression Scale, Oswestry Disability Index, EuroQol-5D, and Short Form Health Survey Questionnaire, respectively. Methods: Eligible participants will be randomized into either renal denervation (treatment group) or a sham treatment (control group). Data (pain, quality of life, mood, disability) will be collected from both groups at baseline, 6 weeks, 3 and 6 months after the intervention. After the initial 6-month follow-up is over, the participants who received the sham procedure will cross over into the treatment group and will be followed for an additional 6 months in the same manner as the treatment group. Descriptive statistics will be used to report outcomes for all patients. Limitations: Single-center study, small sample size. Conclusions: The lessons learnt from this trial will lay the framework and direction for conducting a multisite randomized controlled trial involving a larger cohort of patients. Trial registration: ClinicalTrials.gov (NCT04332731).