Comparison of Conventional and Step-Wise Shockwave Lithotripsy in Management of Urinary Calculi

Abstract

Step-wise SWL yielded better outcomes than conventional SWL without increased morbidity. Stepwise SWL can be considered as a management option for urinary calculi.

Comparison of treatment outcomes according to output voltage during shockwave lithotripsy for ureteral calculi: a prospective randomized multicenter study

“…From previous studies on renal calculi [10,11], escalating voltage resulted in an absolute increase in SFR by 30 %, compared to fixed voltage. We hypothesized that escalating voltage for UC would be associated with the same degree of benefit (approximately 30 %) as for renal calculi (group C: 50 % vs. group E: 80 %).…”

“…In vitro [7,8], animal [9], and two clinical studies [10,11] showed improved stone fragmentation with voltage escalation compared to constant or decreasing voltage. Demirci et al [10] reported a significantly higher SFR at 8 weeks after single or multiple session of SWL in the escalating voltage group compared to the fixed voltage group. Lambert et al [11] also reported similar findings as evaluated at 1 month after a single SWL.…”

“…Secondary outcomes evaluated were also similar between the two groups, and both groups had acceptable complication rates. Although mounting evidence [7][8][9][10][11] supports improved stone fragmentation in patients with renal calculi using increasing voltage, there are contradicting results regarding this issue. Table 3 summarizes the results of published studies.…”

“…While low voltageinduced tensile force and spallation cause adequate stone fragmentation at earlier stages of SWL [19], increasing power may be necessary for treatment at later stages when small fragments and powder accumulate. Thus, increasing power may be effective in constant stone fragmentation to compensate for screening effects caused by fine fragments which scatter and attenuate subsequent shockwaves [8][9][10][11], and reinforce cavitation bubble formation which is the main mechanism of stone disintegration at later stages of SWL [20,21]. However, Honey et al [12] reported negative results from 160 patients with renal calculi.…”

“…In vitro [7,8], animal [9], and two clinical trials [10,11] have shown better success rates using escalating voltage, compared to fixed voltage. In contrast, other randomized clinical trials showed no difference in treatment outcomes between fixed and escalating voltage [12,13].…”