title: Choosing the correct length of ureteric stent: a formula based on the patient's height compared with direct ureteric measurement.
abstract: OBJECTIVE
  To evaluate a formula based on the patient's height for choosing the correct length of ureteric stent and to compare its accuracy with that of direct ureteric length measurement.
  
  
  METHODS
  Thirty-five patients (41 ureters) with ureteric obstruction were prospectively studied. All received Percuflex 8F double pigtail ureteric stents. Stent lengths were chosen according to patient height: < 5 ft 10 in (<178 cm) = 22 cm; 5 ft 10 in to 6 ft 4 in (178-193 cm) = 24 cm; > 6 ft 4 in (>193 cm) = 26 cm. The final stent position was graded using a 5-point scale (0 representing ideal length, with -2 and +2 being too short and too long respectively). Stent length acceptability using direct ureteric measurement was then estimated using the same 5-point scale; and the results compared.
  
  
  RESULTS
  Patient's height correctly predicted stent length in the majority of ureters (grade 0 = 61%), with no stent being too short. In comparison, direct ureteric measurement oversized the stent in 83%, correctly predicting stent length in only 17%.
  
  
  CONCLUSIONS
  Patient's height is a more reliable guide to ureteric stent length than direct ureteric measurement, particularly in the dilated and tortuous ureter. This may be because the redundant ureter is capable of significant shortening under the influence of the ureteric stent.
authors.affiliation: Department of Radiology, St George's Hospital, London, UK. pimac@waitrose.com
authors.forename: J M
authors.initials: JM
authors.lastname: Pilcher
authors.forename: U
authors.initials: U
authors.lastname: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry / Q000379:methods; D001827:Body Height; D004867:Equipment Design; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015607:Stents; D014513:Ureter / Q000000981:diagnostic imaging / Q000473:pathology*; D014517:Ureteral Obstruction / Q000473:pathology / Q000601:surgery*