title: To clot or not to clot? That is the question in central venous catheters.
abstract: OBJECTIVE
  To establish the relationship between the tip position of tunnelled central venous catheters (CVC) and the incidence of venous thrombosis.
  
  
  METHODS
  A randomly sampled, retrospective review of 428 CVC inserted into 334 patients was performed. The chest radiograph obtained post-catheter insertion, as well as follow-up radiographs, linograms, venograms and Doppler ultrasounds (US), were reviewed.
  
  
  RESULTS
  The median follow-up was 72 days (range 1-720 days), with a total follow-up of 23,040 line days. Venous thrombosis occurred in five out of 191 (2.6%) CVC in a distal position (distal third of the superior vena cava (SVC) or right atrium (RA)), five of 95 (5.3%) in an intermediate position (middle third of the SVC) and 20 of 48 (41.7%) in a proximal position (proximal third SVC or thoracic inlet veins). There was a significant difference in thrombosis rate between lines sited with the tip in a distal compared with a proximal position (p<0.0005). CVC with tips in a proximal position were 16 times more likely to thrombose than those in a distal position. None of the 58 CVC with the tip located in the RA thrombosed or caused complications.
  
  
  CONCLUSIONS
  Distal placement of tunnelled CVC, either in the distal third of the SVC or proximal RA is optimal.
authors.affiliation: University of Manchester Medical School, Manchester, UK.
authors.forename: A
authors.initials: A
authors.lastname: Cadman
authors.forename: J A L
authors.initials: JA
authors.lastname: Lawrance
authors.forename: L
authors.initials: L
authors.lastname: Fitzsimmons
authors.forename: A
authors.initials: A
authors.lastname: Spencer-Shaw
authors.forename: R
authors.initials: R
authors.lastname: Swindell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D018608:Ultrasonography, Doppler; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology*