D-dimer plasma level: a reliable marker for venous thromboembolism after elective craniotomy

Area of Science:

• Neurosurgery
• Vascular Surgery
• Diagnostic Medicine

Background:

• Deep venous thrombosis (DVT) incidence post-craniotomy can reach 50%.
• Standard D-dimer thresholds for venous thromboembolism (VTE) in outpatients are unreliable in postoperative patients.
• Postoperative D-dimer levels are hypothesized to be systematically elevated.

Purpose of the Study:

• To test if D-dimer levels are systematically raised post-craniotomy.
• To establish a reliable D-dimer threshold for VTE identification in postoperative patients.
• To investigate the diagnostic utility of D-dimer in craniotomy patients.

Main Methods:

• 101 patients undergoing elective craniotomy were assessed.
• Lower extremity Doppler ultrasonography was used for DVT evaluation pre- and post-surgery.
• D-dimer levels were measured preoperatively and on postoperative days 3, 7, and 10.

Main Results:

• Postoperative D-dimer levels were systematically elevated and significantly differed between patients with and without VTE.
• A D-dimer threshold of >2 mg/L on postoperative day 3 demonstrated 95.3% sensitivity and 74.1% specificity for VTE.
• All patients (n=9) with postoperative pulmonary embolism (PE) had D-dimer levels >4 mg/L.
• Ventilation time and surgery duration were significant VTE risk factors.

Conclusions:

• A postoperative D-dimer threshold of 2 mg/L accurately indicates VTE in craniotomy patients.
• Higher D-dimer levels (>4 mg/L) may suggest pulmonary embolism.
• The predictable pattern of postoperative D-dimer levels could be applicable to other surgical procedures.