• nephrolithiasis;
  • flexible ureteroscopy;
  • renal and proximal ureteral calculi

Study Type – Therapy (case series)

Level of Evidence 4

What's known on the subject? and What does the study add?

Large upper tract urinary calculi, greater than 2 cm, have historically been treated with percutaneous nephrostolithotomy. In general, there has been a growing interest in employing retrograde, flexible ureteroscopy and laser lithotripsy in select patients who are either poor medical candidates for percutaneous lithotripsy or who may prefer a less invasive intervention. Properly selecting patients for this approach, designing specific treatments based on complex stone presentation and offering general information with regard to long-term outcomes and surgical risks have historically been based on results from small, multicentre series lacking uniformity of technique and long-term outcomes.

Our initial multicentre experience employing ureteroscopic techniques to treat large upper urinary tract calculi was presented in 1998. This current work represented the largest single-centre experience, accrued prospectively over 10 years, where there was uniformity of technique and treatment algorithms. This study frames an argument for retrograde ureteroscopic lithotripsy not only in those who are at high risk for percutaneous nephrostolithotomy but in all who present with large, non-infected stone burdens.


  • • 
    To define the safety and efficacy of retrograde ureteroscopic lithotripsy in treating large, non-infectious intrarenal and proximal ureteral stone burdens.


  • • 
    Between 2000 and 2011, 145 patients with 164 large (2 cm or greater in diameter on standard imaging) non-infectious upper intrarenal and proximal ureteral calculi were chosen for retrograde ureteroscopic lithotripsy.
  • • 
    Patients were treated with small diameter flexible fibre-optic ureteroscopes and holmium laser lithotripsy by a single surgeon.
  • • 
    Second-look ureteroscopy was performed in patients with the largest calculi in whom there was a high index of suspicion of significant residual fragments.
  • • 
    Stone clearance was defined as no fragments or a single fragment less than or equal to 4 mm in diameter on standard radiograph and sonography at 3-month follow-up.


  • • 
    Our study included 103 male patients and 42 female patients with an average age of 55 years (range 16–86 years) and a mean stone diameter of 29 mm (range 20–70 mm) including 36 partial staghorn stone burdens (mean diameter 37 mm). Overall, 266 ureteroscopies were performed on 164 stone burdens (1.6 procedures per stone burden), clearing 143 stone burdens (87%).
  • • 
    The highest clearance rates were observed for proximal ureteral (97%) and renal pelvic (94%) stones, while the lowest clearance rates were observed for lower pole (83%) and staghorn calculi (81%).
  • • 
    Three patients required subsequent percutaneous therapy due to infectious material encountered at the time of ureteroscopy or inaccessible stone burdens secondary to infundibular stenosis.
  • • 
    There were five minor postoperative complications, including four fevers and one patient with gross haematuria and clot retention, with no major intraoperative complications.


  • • 
    In select patients, large, complex, metabolic upper urinary tract calculi can be treated safely and efficiently with retrograde ureteroscopic techniques.
  • • 
    Staged, retrograde, flexible ureteroscopy is an alternative to percutaneous therapy with acceptable efficacy and low morbidity.