title: A new coaxial catheter system with an echodense tip for ultrasonographically guided embryo transfer.
abstract: OBJECTIVE
  To determine performance of a new coaxial catheter system with an echodense tip for imaging during transabdominal ultrasonographically guided catheter passage.
  
  
  METHODS
  Prospective, descriptive, noncomparative study.
  
  
  METHODS
  Fertility center within a tertiary care center.
  
  
  METHODS
  Twenty-five patients who were undergoing ET.
  
  
  METHODS
  The catheter was passed transcervically under transabdominal ultrasonographic guidance.
  
  
  METHODS
  The catheter was assessed for ease of placement and immediacy of identification of the outer and inner sheaths and the degree of catheter movement (if any) needed for identification.
  
  
  RESULTS
  The outer sheath of the system was well visualized through the cervix and into the lower uterine segment due to its thickness. Immediate recognition of the echodense tip of the inner sheath was achieved in all patients. With minimal movement of the catheter or ultrasonographic transducer, the tip could be easily tracked during passage through the entire uterine cavity into the fundal region.
  
  
  CONCLUSIONS
  In this preliminary study, the echodense tip was immediately identified by transabdominal imaging, reducing the need to move the catheter for identification. Previous investigations have not conclusively shown improved pregnancy rates with ultrasonographic guidance, possibly because of the need for catheter movement for identification of the tip and resultant disruption of the endometrium. The immediate identification of the catheter may provide a method for precise, atraumatic ET.
authors.affiliation: Center for Fertility and Reproductive Endocrinology, Virginia Mason Medical Center, Seattle, Washington 98110, USA.
authors.forename: G S
authors.initials: GS
authors.lastname: Letterie
authors.forename: L
authors.initials: L
authors.lastname: Marshall
authors.forename: M
authors.initials: M
authors.lastname: Angle
mesh_terms: D002404:Catheterization / Q000295:instrumentation* / Q000379:methods; D004624:Embryo Transfer / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D005260:Female; D006801:Humans; D011247:Pregnancy / Q000706:statistics & numerical data*; D011446:Prospective Studies; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods; D014599:Uterus / Q000000981:diagnostic imaging*