Objectives: In delayed extracorporeal shock wave lithotripsy (ESWL) treatment, increasing stone impaction is associated with delayed stone clearance. Whether colic patients treated by rapid ESWL have the same time to stone clearance as noncolic patients, which supports the thesis that stones in both groups are nonimpacted, has not been investigated yet, and was the objective of this study.
Methods: A total of 82 patients were prospectively enrolled and treated with piezoelectric ESWL for a solitary proximal ureteral stone. Of these, 56 patients experienced at least one colic episode compared with 26 noncolic patients. Hydronephrosis has been assessed with the use of ultrasound and intravenous urography (IVU). Time to stone clearance after the first ESWL and stone-free rates after a follow-up period of 3 mo were recorded.
Results: In colic and noncolic patients, mean stone size was 7.8mm (p=0.7). Ultrasound-detected hydronephrosis was present in 88% versus 39% (p<0.0001), whereas IVU-detected hydronephrosis was present in 60% versus 7.7% (p=0.0001). Mean number of impulses applied was 8000+/-4000 versus 6700+/-3400 (p=0.1). Mean time to stone clearance was 9.5+/-12.1 d versus 4.6+/-3.8 d (p=0.1). Colic and noncolic patients were considered as treatment success in 83% and 81% after 3 mo of follow-up (p=0.9).
Conclusions: Treatment outcome and time to stone clearance after rapid ESWL in colic patients compared with noncolic patients is comparable and independent of concomitant hydronephrosis. This finding suggests an absence of significant impaction in proximal ureteral stones treated within 24h after a first colic episode, enforcing the concept of performing rapid ESWL in patients harbouring proximal ureteral stones.