Panah A et al, 2013: Factors predicting success of emergency extracorporeal shockwave lithotripsy (eESWL) in ureteric calculi-a single centre experience from the United Kingdom (UK)
Panah A, Patel S, Bourdoumis A, Kachrilas S, Buchholz N, Masood J
Endourology and Stone Services, Barts Health NHS Trust, London, UK
Few studies show that "emergency extracorporeal shockwave lithotripsy (eESWL)" reduces the incidence of ureteroscopy in patients with ureteric calculi. We assess success of eESWL and look to study and identify factors which predict successful outcome. We retrospectively studied patients presenting with their first episode of ureteric colic undergoing eESWL (within 72 h of presentation) over a 5-year period. Patient's age, gender, stone size and location, time between presentation and ESWL, number of shock waves and ESWL sessions, and Hounsfield units (HU) were recorded. 97 patients (mean age 40 years; 76 males, 21 females) were included. 71 patients were stone free after eESWL (73.2 %) (group 1) and 26 patients failed treatment and proceeded to ureteroscopy (group 2). The two groups were well matched for age and gender. Mean stone size in group 1 and 2 was 6.4 mm and 7.7 mm, respectively, (p = 0.00141). Stone location was 34, 21, and 16 in upper, middle and lower ureter in group 1 compared to 11, 5, and 10 in group 2, respectively. Mean HU in group 1 was 480 and 612 in group 2 (p value 0.0036). In group 2, significantly, more patients received treatment after 24 h compared with group 1 (38 vs 22.5 %). The number of shock waves, maximal intensity, and ESWL sessions were not significantly different in the two groups. No complications were noted. eESWL is safe and effective in patients with ureteric colic. Stone size and Hounsfield units are important factors in predicting success. Early treatment (≤24 h) minimizes stone impaction and increases the success rate of ESWL.
Urolithiasis. 2013 Jun 9. [Epub ahead of print]
PMID:23748923 [PubMed - as supplied by publisher]
The advantage of early- emergency - SWL for removal of ureteral stones is an attractive therapeutic approach which previously has been discussed in the literature. The message of the present report is that such a treatment should be carried out as early as possible and it seems desirable to come to treatment within the first 24 hours. It is, however, somewhat surprising that the treatment was considered a failure in as many as 27% of the patients despite a mean of 1.9 SWL sessions. The issue aimed at in the title: "factors predicting success", is only partly responded in the article and then in vague terms applicable to every series of SWL procedures. In addition to determinants as size and hardness it appears necessary to analyse in more detail why the stones in Group B were not disintegrated, because also large and hard stones should be possible to break if properly hit by the shock wave.