Retrograde intrarenal surgery for renal stones smaller than 2 cm

Ho CCK, Hafidzul J, Praveen S, Goh EH, Bong JJ, Lee BC, Zulkifli MZ
Correspondence: Dr Christopher Ho Chee Kong, chrisckho2002@yahoo.com

ABSTRACT
Introduction Extracorporeal shock wave lithotripsy (ESWL) is accepted as the gold standard treatment for renal stones that are smaller than 2 cm. Recently, retrograde intrarenal surgery (RIRS) has been introduced as another form of treatment. We report our experience in dealing with renal stones smaller than 2 cm using RIRS as the primary treatment and following failed ESWL.
Methods A retrospective analysis was conducted over a five-year period on patients with stone(s) measuring less than 2 cm each and who had undergone RIRS. The patients were divided into two groups: RIRS as the primary procedure and RIRS post-ESWL.
Results A total of 46 patients underwent RIRS in our institute. The total stone clearance rate was 61 percent. The clearance rate was better for RIRS as the primary procedure when compared to RIRS as an adjunct procedure (70 percent versus 52 percent; p-value is 0.23). Patients with mid-pole stones achieved an 80 percent stone clearance rate as compared to 60 percent for those with lower pole stones. The clearance rate for upper pole stones was only 29 percent. When RIRS was the primary procedure for lower pole stones, the success rate was 75 percent, compared to 56 percent when it was used as an adjunct procedure post-ESWL.
Conclusion For renal stones measuring less than 2 cm, the stone clearance rate for RIRS was as good as that for EWSL as a primary procedure and achieved a good clearance rate following the failure of ESWL.

Keywords: extracorporeal shock wave lithotripsy, kidney calculi, lithotripsy, retrograde intrarenal surgery, therapy
Singapore Med J 2010; 51(6): 512-515