High incidence of intravenous thrombi after short-term central venous catheterization of the internal jugular vein.

Study Objective: To assess incidence and characteristics of intravenous (i.v.) thrombi associated with short-term central venous catheterization through the internal jugular vein.

Design: Prospective clinical study.

Setting: University hospital.

Patients: 81 patients undergoing cardiac surgery.

Interventions: A triple-lumen central venous catheter was inserted into the right internal jugular vein immediately before surgery and removed 3 to 4 days later. Heparin at an i.v. dose of 15,000 IU/24 hours was started 6 hours after surgery and continued until the first postoperative morning, followed by subcutaneous low molecular weight heparin 5,000 IU/day in combination with oral aspirin 100 mg/day.

Measurements And Main Results: Anatomy of the internal jugular vein and i.v. blood flow were studied using two-dimensional and color Doppler ultrasonography before insertion of the catheter and after its removal. Thrombi were found in 45 patients (56%). Twenty-five of these thrombi (56%) had the shape of a sleeve, and 20 thrombi (44%) were compact. Length of the thrombi was 1.4 +/- 0.8 cm (mean +/- SD). Half of the thrombi floated with venous blood flow and half were stable. Neither impaired venous blood flow nor clinical signs of embolism or sepsis was found. Follow-up studies in eight patients revealed that the thrombi had not disappeared 5 days after removal of the catheter but had become smaller.

Conclusion: The incidence of i.v. thrombi associated with short-term catheterization of the internal jugular vein was high despite prophylactic anticoagulation. This finding reaffirms the importance of removing central venous catheters as soon as clinically possible. Additional studies using specific outcome tests are needed to thoroughly assess the clinical importance of this finding.