title: Optimization of silicone urinary catheters for hypospadias repair.
abstract: OBJECTIVE
  We have experienced difficulty with the removal of all-silicone Foley catheters after hypospadias repair, relating to the formation of a 'cuff' of residual balloon material that fails to deflate, after aspiration of the instilled volume of water. This could potentially lead to both short- and long-term complications (stenosis, fistula). In all-silicone paediatric catheters, we investigated the production of such 'cuffs', and any other significant deformity which may be associated with deformation of the catheter balloon mechanism, in vitro.
  
  
  METHODS
  Catheters were inflated with 0 (control) to 7 mL of sterile water. The catheter balloon dimensions were measured before and after incubation of the catheters for 168 h in a solution simulating human urine. The aspiration volumes were recorded.
  
  
  RESULTS
  At volumes greater than 40% of the manufacturer's advised inflation volume, a significant increase in the transverse diameter of the catheter occurred after deflation, compared to controls (P<0.001).
  
  
  CONCLUSIONS
  We advise the maximum instillation of 2 mL of water into a 5-mL paediatric catheter balloon to avoid cuff formation. Using this technique allows all of the advantages of a stent, in combination with the security of a catheter, but with a reduced risk of trauma and complications associated with catheter removal.
authors.affiliation: Welsh Centre for Burns and Plastic Surgery, Abertawe Bro Morgannwg NHS Trust, Morriston Hospital, Swansea, UK. hardwickej@doctors.org.uk
authors.forename: Joseph
authors.initials: J
authors.lastname: Hardwicke
authors.forename: Ernesto
authors.initials: E
authors.lastname: Jones
authors.forename: Nicholas
authors.initials: N
authors.lastname: Wilson-Jones
mesh_terms: D002404:Catheterization / Q000295:instrumentation*; D002648:Child; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D007021:Hypospadias / Q000601:surgery*; D008297:Male; D014546:Urinary Catheterization / Q000295:instrumentation*