Stenting in extracorporeal shockwave lithotripsy; may enhance the passage of the fragments!

To prospectively evaluate the role of double J (DJ) stent in enhancing the passage of fragments in patients undergoing extracorporeal shockwave lithotripsy (SWL) for renal stones with diameters less than 2.5 cm.

Between November 2005 and January 2007, 38 patients with an average age of 47.05 years (range 16-73) were included and underwent SWL for renal stones. The inclusion criteria were radio-opaque renal stone not located in the lower pole, complete disintegeration of the stone, normal renal function, no metabolic abnormalities, no major renal abnormalities and no symptomatic urinary tract infection. The patients were randomized to either a stented (11 patients) or stentless (27 patients) group. The average stone diameters in stentless and stented groups were 1.54 cm and 1.77 cm, respectively (p > 0.05). Double J stent was removed when there was no further passage of the fragments for 6 weeks after stone disintegration. All patients were given non-steroidal anti-inflammatory drugs for one week after ESWL treatment. Stone passage and the data of DJ were determined with plain X-ray of the urinary tract (UTP). The severity of lower urinary tract symptoms, loin pain and the need for intravenous or intramuscular analgesics were recorded.

The overall stone-free rate at 3 months was 92.1%. Two patients in the stented and one patient in the stentless group were partially free of stones. Steinstrasse were observed in two patients (5.3%); one patient in the stentless group and another one after the removal of DJ stent. Only one patient in the stented group had severe lower urinary tract symptoms which responded neither to oral nor to other forms of analgesics, and therefore DJ stent was removed. The remaining patients were in no need for analgesics other than the oral therapy.

Placement of DJ stent for the purpose of improving free stone rate or enhancing the passage of the fragments during SWL is unnecessary in renal stone with diameters less than 2.5 cm. However, further prospective trials should be designed to define the criteria for stented SWL.