Another method for localization of radiolucent urinary stones during ESWL

Abstract EN

Objectives : 1.

To study the feasibility and safety of localization of radiolucent urinary stones during ESWL utilizing the refluxing intravesically injected contrast medium along indwelling ureteral stents.

2.

To identify the optimum volume of contrast medium and the intravesical pressure at which adequate vesicoureteric reflux sufficient for collecting system pacification occurs.

3.

To identify criteria by which successful localization can be predicted.

Methods : With antibacterial prophylaxis, hundred mls.

of contrast medium diluted with 500 ml normal saline was infused into the bladder through a Y shaped connection attached to a pre-inserted urethral catheter with the other limb connected to a water manometer for the purpose of continuous intravesical pressure recordings.

The amount of infused contrast medium and intravesical pressure at which adequate visualization by fluoroscopy occurred was recorded.

Successful stone localization was correlated with the infused contrast medium volume, intravesical pressure, infection, stone location, age, weight, stent duration and fluoroscopy time.

Results : Forty six patients were studied.

Clear stone localization to facilitate shock targeting was achieved in 37 patients (80 %).

This occurred with a mean contrast volume of 300 ml at 20 cm water mean intravesical pressure.

Apart from urinary tract infection which was associated with a significantly lower success rate, there were no other criteria by which success can be predicted.

There were no significant complications and all visualized stones disintegrated well and were completely cleared at 3 months.

Conclusions : The method is safe, easy repeatable and suitable for targeting radiolucent urinary stones during ESWL in patients with ureteral stents.