Can prestenting before retrograde intrarenal surgery be performed under local anesthesia with IV sedation in appropriate patients?

Prestenting Before RIRS Under Local Anesthesia

Yes, prestenting before retrograde intrarenal surgery (RIRS) can be performed under local anesthesia with IV sedation in appropriate patients, following established day surgery protocols for regional/local procedures. 1

Anesthetic Approach for Prestenting

Primary Recommendation: Local Anesthesia with Conscious Sedation

The procedure can be safely performed using local anesthesia combined with titrated IV sedation, as stent placement is a brief, minimally invasive procedure that does not require general anesthesia. 1

• Sedation protocol: Administer midazolam in small incremental doses (1-2 mg) titrated slowly over at least 2 minutes with 2-3 minute intervals between doses 2
• Local anesthetic: Use lidocaine or mepivacaine for urethral/periurethral anesthesia, as both are safe and effective 1
• Monitoring requirements: Maintain continuous pulse oximetry, blood pressure monitoring, and ECG throughout the procedure 2

Patient Selection Criteria

Appropriate candidates include:

• Hemodynamically stable patients without severe cardiovascular disease 2
• Patients without active urinary tract infection 3
• Cooperative patients who can tolerate brief cystoscopy 1
• ASA I-II patients, or carefully selected ASA III patients with dose reduction 4

High-Risk Patient Modifications

For elderly or frail patients:

• Reduce midazolam doses by 50% from standard dosing 2
• Consider remimazolam as an alternative due to superior cardiovascular stability and reversibility with flumazenil 4
• Target sedation level where patient remains quiet but responsive to verbal stimuli 1, 2

For patients with respiratory disease:

• Use reduced sedation doses (50% less than standard) 2
• Maintain continuous respiratory monitoring with immediate availability of resuscitation equipment 2
• Consider dexmedetomidine as an alternative to benzodiazepines for lower risk of respiratory depression 2

Clinical Rationale for Prestenting

Evidence Supporting Prestenting

Prestenting before RIRS improves surgical outcomes, particularly for renal stones, by facilitating ureteral access sheath placement. 1

• Access sheath success: Prestenting increases successful sheath placement from 85.3% to 93.8% (p = 0.023) 5
• Optimal timing: Perform RIRS within 15-20 days after stent insertion to minimize postoperative infection risk (lowest infection rate in 0-15 day group, p = 0.046) 6
• Stone-free rates: No significant difference in stone-free rates between pre-stented (85.8%) and non-stented (83.2%) groups, but improved surgical access 5

When Prestenting is Most Beneficial

Consider prestenting for:

• Renal stones requiring RIRS, especially when access sheath placement is anticipated 5
• Patients with anticipated difficult ureteral access 5
• Larger stone burden where optimal access is critical 1

Safety Considerations and Monitoring

Mandatory Requirements

• Resuscitation equipment: Must be immediately available including airway management tools 2
• Trained personnel: Staff trained in airway management should be present and dedicated to patient monitoring 2
• IV access: Maintain throughout procedure and recovery period 2
• Recovery criteria: Patient must meet standard day surgery discharge criteria before leaving facility 1

Common Pitfalls to Avoid

• Oversedation: Excessive sedation causes hypoxia, hypercapnia, and hypotension through airway loss and ventilation depression 1, 2
• Inadequate monitoring: Failure to maintain continuous respiratory and cardiac monitoring increases risk 2
• Prolonged stent duration: Stents left >20 days before RIRS increase postoperative infection risk 6
• Combining sedatives without dose reduction: When combining sedatives with opioids, reduce each component appropriately 2

Discharge Planning

Patients can be discharged home with:

• Written instructions about expected stent symptoms and when to seek care 1
• Alpha-blockers prescribed to reduce stent discomfort 1
• Anti-muscarinics as alternative for symptom relief 1
• Clear instructions about timing of definitive RIRS procedure (ideally within 15-20 days) 6