Table 1: Basic characteristics of studied patients.

Variables Group IGroup IIGroup IIIGroup IV value
C groupT groupS groupT/S group

Number of patients81828084< 0.05
Mean age (years)
Sex (male : female)1.6 : 12 : 12.5 : 12.2 : 1
Indications of stent placement
 URS/ureterolithotomy56575963
 PCNL07100705
 ESWL16141213
 Endopyelotomy 02010203

URS: Ureterorenoscopy; PCNL: Percutaneous Nephrolithotomy; ESWL: Extracorporeal Shock Wave Lithotripsy.