The Case against Chemoprophylaxis for Venous Thromboembolism Prevention and the Rationale for SAFE Anesthesia

Abstract

Summary:The Venous Thromboembolism Prevention study concludes that anticoagulation is effective in reducing the risk of thromboembolism in patients who are identified as higher risk by Caprini scores. This report critically assesses the statistics used in the Venous Thromboembolism Prevention study, its method of data presentation, and its conclusions. The usefulness of risk stratification and the value of anticoagulation—both prevailing concepts in risk reduction today—are challenged. Actual data show that chemoprophylaxis has no proven benefit in plastic surgery. Complications of anticoagulation predictably include excessive bleeding and hematomas, which may be serious and life-threatening. Several large published series of patients undergoing elective plastic surgery under total intravenous anesthesia have shown a much reduced risk of thromboembolism. A SAFE (Spontaneous breathing, Avoid gas, Face up, Extremities mobile) anesthesia method is discussed as a safer and more effective alternative to traditional general endotracheal anesthesia and anticoagulation. The choice for plastic surgeons is not between a venous thromboembolism and a hematoma. The choice is between a thromboembolism and adjusting our anesthesia and surgery habits to reduce the risk to a baseline level.

Benefits and Risks of Prophylaxis for Deep Venous Thrombosis and Pulmonary Embolus in Plastic Surgery

“…The calf muscle pump propels venous blood cranially and, in concert with the venous valve system, mitigates venous stasis and venous dilation. Many large case series and uncontrolled trials that examine muscle-pump-preserving anesthetic mechanisms [50][51][52][53] state that maintenance of the calf muscle pump during surgical procedures decreases the risk for deep venous thrombosis. This logic has face validity, and supports the role of early ambulation and alteration in anesthetic management, especially using anesthesia that preserves the calf muscle pump, as a mechanism for deep venous thrombosis prevention.…”

Combined Breast Surgery and Abdominoplasty

“…Swanson, however, writes in his review that the data presented in the article by Pannucci et al do not offer evidence of venous thromboembolism protection with enoxaparin. 42,44,56 He advocates other forms of venous thromboembolism prophylaxis, including total intravenous anesthesia, avoidance of prone positioning, and avoidance of paralysis. 42,56 Other forms of chemoprophylaxis have also been investigated.…”

“…42,44,56 He advocates other forms of venous thromboembolism prophylaxis, including total intravenous anesthesia, avoidance of prone positioning, and avoidance of paralysis. 42,56 Other forms of chemoprophylaxis have also been investigated. Dini et al, for example, attempted to investigate the efficacy of the oral venous thromboembolism prophylactic agent rivaroxaban; this study was terminated early because of high hematoma rates in the treatment group.…”

“…1 The role (if any) of pharmacologic intervention for venous thromboembolism prophylaxis may be considered controversial by some and is still evolving. 33,37,39,40,[42][43][44][45][46][47][48][49][50][51][52][53][54][55] Swanson holds that there is presently "no evidence of a benefit from anticoagulation in reducing the rate of venous thromboembolism in plastic surgery patients." 56 He cites the thromboembolism prevention study by Pannucci et al 49 as the only large-scale controlled trial of venous thromboembolism chemoprophylaxis in plastic surgery patients.…”

Chemoprophylaxis for Venous Thromboembolism Prevention

“…7 This statement may be true, if one accepts that these predictions are wrong 97 percent of the time and that 48 percent of affected patients are missed. 4 The case for chemoprophylaxis is undermined by (1) nonsignificant p values in the Venous Thromboembolism Prevention Study, 8 (2) equal complication rates (1.2 percent) in both treatment and control groups, (3) questionable statistical adjustments, and (4) unacceptable false-positive rates and sensitivity. 4 To my knowledge, advocates of chemoprophylaxis have not addressed these concerns in the form of any communications to the Journal.…”