Standardized flexible ureteroscopic technique to improve stone-free rates

Objective: To present a unique completely standardized sequence of steps performed before, during, and after flexible ureteroscopy (FURS) that achieves superior results for FURS treatment of renal calculi.

Materials and methods: The "Freiburg FURS technique" includes the following steps: (a) preoperative ureteral stenting; (b) placement of 2 hydrophilic wires; (c) semirigid ureteroscopy before FURS; (d) the use of a large access sheath (14F-16F) if multiple ureteral passages are expected; (e) the use of a 2-working channel flexible endoscope; (f) a modified active flushing system; and (g) an advanced holmium laser technique with complete stone extraction. We performed a prospective analysis of 153 consecutive FURS procedures for nephrolithiasis from August 2009 to July 2011.

Results: Data analysis revealed an "immediate" stone-free rate of 96.7% (as confirmed by endoscopy, fluoroscopy, and ultrasonography), a medium of 2.3 stones, and a cumulative stone size of 10.5 mm (range 3-43). The operative time was 67 minutes (range 20-160). The use of an access sheath was required in 71% of the patients and the postoperative use of a double-J stent in 57% of patients. Complications (Clavien grade II and III) developed in 9.1% of patients (including 7 with minimal perforation that required ureteral stenting for 1 month, 3 with secondary flank pain/hydronephrosis requiring double-J stenting and hospitalization, and 4 with fever or urinary tract infections requiring antibiotic therapy. Follow-up examinations after 3 months showed no late complications.

Conclusion: The modified FURS technique provided clinically superior results with a low complication rate. However, the approach requires the use of considerable resources, both technical and surgical and financial.