Relation between peri-operative antithrombin activity and deep vein thrombosis after elective hip replacement surgery

Area of Science:

• Thrombosis research
• Orthopedic surgery outcomes
• Pharmacodynamics

Background:

• Deep vein thrombosis (DVT) is a risk after hip replacement.
• Low-molecular-weight heparin (LMWH) is used for DVT prevention.
• The role of antithrombin (AT) activity in LMWH efficacy requires clarification.

Purpose of the Study:

• To investigate the relationship between preoperative and postoperative antithrombin (AT) activity and deep vein thrombosis (DVT) occurrence.
• To assess if AT activity depletion or preoperative levels predict DVT in patients undergoing hip replacement.
• To evaluate the impact of LMWH on DVT prevention in relation to AT levels.

Main Methods:

• Prospective study of 93 patients undergoing elective hip replacement.
• Measurement of AT activity and laboratory parameters preoperatively and daily for one week postoperatively.
• Color-coded compression sonography performed before and after surgery to detect DVT.

Main Results:

• The incidence of DVT was 8.6%.
• Patients with DVT exhibited significantly lower preoperative AT activity (80.6%) compared to those without DVT (98.1%).
• No significant association was found between postoperative AT activity changes, blood loss, or transfusions and DVT occurrence.

Conclusions:

• A subset of patients may have insufficient preoperative AT activity for effective LMWH prophylaxis.
• Low preoperative AT activity is a risk factor for postoperative DVT after hip surgery.
• Monitoring preoperative AT activity may identify patients at higher risk for DVT.