Preventing Retrograde Stone Displacement During Pneumatic Lithotripsy For Ureteral Calculi Using Lidocaine Jelly

Retrograde displacement of calculi within the ureter during ureteroscopy and lithotripsy is a common and annoying complication. Some devices have been developed to prevent stone displacement but these devices, usually specially designed baskets, do add to disposable costs. Recently, M. G. Mohseni and colleagues from Tehran, Iran, completed a clinical trial to examine the efficacy of the instillation of lubricating jelly proximal to a ureteral stone to prevent migration during subsequent ureteroscopy. The report of the trial is published in the September 2006 issue of Urology.

In the trial, 34 patients with upper ureteral calculi less than 2 cm were randomized into two groups: jelly instillation (n = 16) and controls (n = 18). Ureteroscopy was performed using a 9.8F semirigid ureteroscope and lithotripsy was done with a Swiss lithoclast. In the instillation group, a 5F ureteral stent was advanced beyond the stone and 2 ml of lidocaine jelly was instilled prior to the lithotripsy. A 5F ureteral catheter was left in place for 24 hours and a KUB was performed at 24 hours and an IVU at 2 weeks post-op.In both groups, the stone was merely fragmented into small pieces, no baskets were used to retrieve stone particles and remove them. At the conclusion of the procedure in the treatment group, the ureter was lavaged with normal saline to break up the lubricating jelly.Analysis of results showed that stone or stone fragment migration occurred in 12.4% of the treatment group and 44.4% of the controls, statistically significantly different (P = 0.046). The stone-free rate was 93.7% and 83.3% in the treatment and control groups, respectively. This difference was not statistically different.In reviewing this article, I feel that there may be some advantage of this technique but only if retropulsed fragments are routinely chased and removed which can add considerably to OR time. If the plan is to fragment into small pieces and let the patient pass them spontaneously, it seems to me that there is no difference if the fragments are caught in jelly or allowed to go into the kidney, unless the fragments reach the lower pole calices which may decrease the possibility of passage. If the jelly is irrigated after the ureteroscopy, it really seems that any potential advantage is also "washed away".(Source: Urology : December 2006.)