Aim: To establish the relationship between the tip position of tunnelled central venous catheters (CVC) and the incidence of venous thrombosis.
Materials and 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.
Conclusion: Distal placement of tunnelled CVC, either in the distal third of the SVC or proximal RA is optimal.