title: Critical analysis of a new generation electrohydraulic lithotripter: a single institution experience with the Medispec e3000.
abstract: OBJECTIVE
  The Medispec E3000(™) is a new generation electrohydraulic lithotripter with a wider focal width comparable to the Dornier HM3(™). We evaluate the efficacy of this machine for management of urinary stones at our institution by shockwave lithotripsy (SWL).
  
  
  METHODS
  There were 168 urinary calculi managed using the Medispec E3000 lithotripter over a 14-month period (10/2010-12/2011). During the first 6 months (10/2010-6/2011), a low power ramping protocol of 11-12-17 kV was used, and for the remaining 6 months (6/2011-12/2011), stones were managed with a higher power ramping protocol of 15-17-22.5 kV. A subanalysis of these groups was performed, as well as for stone location. The major end point was stone-free rate (SFR), defined as fragments <4 mm on follow-up imaging. Data were analyzed using the Fisher exact test and two-tailed Student t test.
  
  
  RESULTS
  The study included 102 males and 66 females with an average age of 52.8 years. Mean stone size was 6.9 × 7.2 mm, which was significantly associated with SFR (P<0.0010). The overall SFR was 64.9%, with no significant difference between stones managed with the low power protocol (61.3%) and the high power protocol (70%). SFR varied by location across the upper pole (64.9%), midpolar area (57.1%), lower pole (68.4%), renal pelvis (79.2%), proximal ureter (66.6%), midureter (83.3%), and distal ureter (53.8%), but these differences were not significant (P=0.59). Efficiency quotient for the Medispec E3000™ was 54%.
  
  
  CONCLUSIONS
  Overall, we achieved SFR of 64.9% in our initial experience with the Medispec E3000™. Optimizing treatment parameters may further improve success rates, and further outcomes follow-up may allow a more comprehensive evaluation of the lithotripter's overall efficacy.
authors: Warren Alpert Medical School at Brown University, Providence, Rhode Island 02905, USA.
authors: Jessica
authors: J
authors: Dai
authors: Vincent
authors: V
authors: Harisaran
authors: Shadi Al
authors: SA
authors: Ekish
authors: Simone
authors: S
authors: Thavaseelan
authors: Gyan
authors: G
authors: Pareek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008096:Lithotripsy / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000628:therapy*; D055815:Young Adult