A novel regional anesthesia technique for retrograde intrarenal surgery in high-risk patients: a prospective observational study

BACKGROUND: Retrograde intrarenal surgery (RIRS) is a minimally invasive treatment for upper urinary tract stones. However, anesthesia management in high-risk patients with significant comorbidities remains challenging, as general anesthesia poses elevated cardiopulmonary risks and spinal anesthesia is often contraindicated. This study aims to describe a novel regional anesthesia strategy combining ultrasound-guided quadratus lumborum block at the lateral supra-arcuate ligament (QLB-LSAL) with an anterior approach of sacral plexus block (SPB) as a potential alternative for RIRS in this vulnerable population. METHODS: This prospective observational study enrolled 24 consecutive high-risk adult patients (ASA III-IV) scheduled for RIRS between February 2022 and May 2024. Patients received bilateral anterior approach SPB followed by unilateral QLB-LSAL. Data collected included the successful completion of surgery under regional anesthesia, conversion rates to general anesthesia, intraoperative pain scores (Numerical Rating Scale, NRS), supplemental analgesic requirements, hemodynamic stability, and block- or surgery-related adverse events. Postoperative pain scores, 30-day stone-free rate (SFR), and patient satisfaction were also assessed. RESULTS: All 24 patients successfully completed RIRS under the combined regional anesthesia without conversion to general anesthesia. Most patients (83.3%) experienced only mild pain during the procedure (peak NRS ≤ 3), while four (16.7%) required supplemental analgesia or sedation. Hemodynamic parameters remained stable throughout the procedures, and no major anesthesia-related complications were observed. The 30-day SFR was 87.5%, which is comparable to reported outcomes under traditional anesthesia methods. Postoperative pain scores were low (median NRS: 0-1), and 91.6% of patients reported high satisfaction with the anesthetic technique. CONCLUSION: QLB-LSAL combined with anterior approach of SPB appears to be a feasible anesthetic strategy for high-risk patients undergoing RIRS. However, given the observational design and small sample size, these findings should be considered preliminary and require validation in larger studies before broader clinical application. CLINICAL TRIAL NUMBER: Not applicable.