title: Impact of power index, hydroureteronephrosis, stone size, and composition on the efficacy of in situ boosted ESWL for primary proximal ureteral calculi.
abstract: OBJECTIVE
  The efficacy, safety, feasibility, and outcome of in situ treatment applied to select proximal ureteral calculi was assessed and analyzed with a view to avoiding auxiliary interventions and providing high clearance rates in the shortest possible time. We studied the impact of several clinically important variables, including power index, degree of hydroureteronephrosis (HDUN), stone size, and composition on the efficacy of sequential in situ boosted extracorporeal shock wave lithotripsy (ESWL) in a select group. The power index requirement for the in situ boosted protocol and the impact of the stone size/composition, degree of HDUN, and clearance rates were also analyzed.
  
  
  METHODS
  An in situ (no instrumentation) boosted protocol was applied to 130 primary unimpacted proximal ureteral calculi with no prior intervention. A typical session with the Siemens Lithostar Plus comprised 3000 shock waves, in installments of 500, deployed at a power setting of 1 to 4 kV with a gradual stepwise escalation. Sequential boosted additional sessions of ESWL were administered on days 2, 7, and 14, tailored to the degree of fragmentation, clearance status, and amount of residual stone bulk. Several parameters (shock waves, kilovolts used, fluoroscopy time, number of sessions, stone size, composition, fragmentation, clearance, and HDUN) were recorded and the results analyzed statistically.
  
  
  RESULTS
  The results were excellent in 83.8%, with a mean duration to complete clearance of 11.3 days. In situ ESWL failed in 7.69%, and the auxiliary intervention rate was 10.7%. Pre-ESWL HDUN was present in 78.3%, the mean power index was 184.6/session/case, and the average stone burden was 8.9 mm(2). Calcium oxalate monohydrate was the most common stone (56%). Renal colic was the most common side effect observed. The power index, fragmentation at the first session, and stone size were found to be the most favorable significant variables affecting stone clearance. The degree of HDUN, number of sessions, and stone composition did not significantly impact the clearance rates.
  
  
  CONCLUSIONS
  In situ boosted ESWL should be the first-line therapeutic modality in select unimpacted primary proximal ureteral stones.
authors.affiliation: Department of Urology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: I
authors.initials: I
authors.lastname: Singh
authors.forename: N P
authors.initials: NP
authors.lastname: Gupta
authors.forename: A K
authors.initials: AK
authors.lastname: Hemal
authors.forename: P N
authors.initials: PN
authors.lastname: Dogra
authors.forename: M S
authors.initials: MS
authors.lastname: Ansari
authors.forename: A
authors.initials: A
authors.lastname: Seth
authors.forename: M
authors.initials: M
authors.lastname: Aron
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002129:Calcium Oxalate / Q000032:analysis; D016009:Chi-Square Distribution; D002648:Child; D003085:Colic / Q000209:etiology; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology; D008096:Lithotripsy / Q000009:adverse effects / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014514:Ureteral Calculi / Q000737:chemistry / Q000175:diagnosis / Q000628:therapy*; D014567:Urography
chemical_list: D002129:Calcium Oxalate