title: Primary SWL Is an Efficient and Cost-Effective Treatment for Lower Pole Renal Stones Between 10 and 20 mm in Size: A Large Single Center Study.
abstract: To assess the clinical features, outcomes, complications, and cost-effectiveness of shockwave lithotripsy (SWL), flexible ureterorenoscopy (FURS), and percutaneous nephrolithotomy (PCNL) in the treatment of lower pole (LP) stones (10-20 mm) in a large tertiary referral center.
  
  
  
  Consecutive patients treated for solitary LP stones (10-20 mm) between 2008 and 2013 were identified from a prospective database. SWL was used as primary treatment in all cases (following a stone multidisciplinary team assessment), with FURS and PCNL reserved for SWL contraindications, failure, or patient choice. "Success" was defined as stone free and/or clinically insignificant stone fragments (≤3 mm) at 1 and 3 months follow-up. Effect of anatomy on SWL success was determined from using CT images and regression analysis. Average cost per treatment modality (including additional second-line treatments) was calculated for each group using the National Health Service England 2014/15 National Tariff Healthcare Resource Group codes.
  
  
  
  Two hundred twenty-five patients were included (mean age 54.9; median stone size 12 mm). One hundred ninety-eight (88%), 21 (9.3%), and 6 (2.7%) patients underwent SWL, FURS, and PCNL as primary treatments, respectively, for median stone sizes of 12, 12, and 20 mm. Overall success rates were 82.8%, 76.1%, and 66.7%, respectively (p < 0.05). Sixty-three percent of patients undergoing primary SWL were effectively treated after one session. Anatomical analysis determined infundibulopelvic angle and infundibular length to be significantly different in patients effectively treated with SWL (p = 0.04). The average cost per treatment modality was also significantly lower for SWL (£750) than for FURS (£1261) or PCNL (£2658) (p < 0.01).
  
  
  
  SWL is both an efficacious and cost-effective primary treatment for patients with solitary LP stones (10-20 mm). The majority of patients can be effectively treated with primary SWL in a dedicated stone center, with the benefits of a short length of stay, low complication, and auxiliary treatment rates. The referral of such patients to high-volume lithotripsy centers with demonstrable outcomes should be given due consideration.
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Luke H
authors.initials: LH
authors.lastname: Chan
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Good
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Karina
authors.initials: K
authors.lastname: Laing
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Simon
authors.initials: S
authors.lastname: Phipps
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Ben G
authors.initials: BG
authors.lastname: Thomas
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Julian Y
authors.initials: JY
authors.lastname: Keanie
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: David A
authors.initials: DA
authors.lastname: Tolley
authors.affiliation: Department of Urology, The Scottish Lithotriptor Centre, Western General Hospital , NHS Lothian, Edinburgh, Scotland.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Cutress
mesh_terms: D000328:Adult; D000368:Aged; D000075202:Contraindications; D003362:Cost-Benefit Analysis; D016208:Databases, Factual; D004739:England; D000074059:Extracorporeal Shockwave Therapy / Q000191:economics / Q000379:methods*; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007668:Kidney; D007669:Kidney Calculi / Q000628:therapy*; D008096:Lithotripsy / Q000191:economics / Q000379:methods*; D008297:Male; D008875:Middle Aged; D000074642:Nephrolithotomy, Percutaneous; D018579:Patient Selection; D011446:Prospective Studies; D012017:Referral and Consultation; D015203:Reproducibility of Results; D062606:Tertiary Care Centers; D016896:Treatment Outcome; D018666:Ureteroscopy / Q000191:economics / Q000379:methods*
keywords: FURS; PCNL; SWL; lower pole; renal calculi; stones