Urgent shock wave lithotripsy as first-line treatment for ureteral stones: a meta-analysis of 570 patients.

The rationale for the use of immediate shock wave lithotripsy (SWL) after a renal colic episode is to obtain maximum stone clearance in the shortest possible time with associated early detection of lithotripsy failures which can be treated with auxiliary procedures. The aim of this meta-analysis is to understand the role of this treatment option in the emergency setting as first-line treatment and to compare such an immediate procedure to a delayed one in terms of stone-free and complication rates. A bibliographic search covering the period from January 1995 to September 2010 was conducted in PubMed, MEDLINE and EMBASE. Database searches yielded 48 references. This analysis is based on the seven studies that fulfilled the predefined inclusion criteria. A total of 570 participants were included. The number of participants in each survey ranged from 16 to 200 (mean 81.42). Six studies were published after 2000 and one in the 1990s. All studies reported participants' age with mean of 40.9 years, and range between 11 and 88 years. All patients presented with unilateral lithiasis, as such the number of total stones treated was 570. Mean stone diameter ranged between 6.38 and 8.45 mm. According to the logistic regression applied stone-free rates were 79 % (61-95) for the proximal ureter, 78 % (69-88) for the mid ureter, 79 % (74-84) for the distal ureter and 78 % (75-82) for overall. Stone-free rates do not evidence a statistically significant difference compared to those described in the AUA and EAU guidelines for elective management. SWL management of ureteral stones in an emergency setting is completely lacking in the international guidelines and they results disperse in the literature in few works. According to our meta-analysis, immediate SWL for a stone-induced acute renal colic seems to be a safe treatment with high success rate. This evidence will be validated by further randomized studies, with a larger series of patients.