Commentary In their article, Ludwick et al. provide data regarding the suitability of aspirin as prophylaxis against venous thromboembolism (VTE) in selected patients with a history of VTE undergoing total joint arthroplasty. Although observational, non-prospective, and nonrandomized, this study raises many questions about the practice of anticoagulation after arthroplasty during the last 50 years in orthopaedic surgery. In 1951, when Harold Ellis sat for the Fellowship examination of the Royal Colleges of Surgeons1, he was advised that, if questioned by an examiner, “What is the best treatment for osteoarthritis of the hip?” he should reply, “Provide the patient with a walking stick and prescribe aspirin.” In that time period, aspirin was given for pain. Later, when arthroplasty became the treatment for hip osteoarthritis, Charnley (cited by Salzman) and Harris2,3, as early as 1971, began to use aspirin to prevent fatal pulmonary embolism. Between 1970 and 2020, arthroplasties were performed with increasing frequency, and the risk of VTE in total hip arthroplasty (THA) was evaluated to be among the highest among procedures in all surgical specialties. Many drugs were tested and approved by regulatory agencies for the prevention of VTE. Yet, despite the millions of dollars spent on pharmaceutical research to develop new anticoagulants, we cannot answer4 this simple question: Which is the best one? Ludwick et al. confirm that aspirin, a drug known for 4,000 years, is still an actual pharmacologic approach for VTE prevention. Around 4,000 years ago5, herbal medicine used salicylic acid (the natural substance) from willow, myrtle, and meadow sweet. In the Assyrian and Sumerian periods, clay tablets recommended willow leaves for rheumatic disease. The aspirin that we know arrived in 1897 when a stabler form, acetylsalicylic acid, was synthesized by the chemist Felix Hoffmann (at Bayer in Germany), and in 1971 it was proposed to prevent VTE2. Why, for 50 years, have the pharmaceutical industry and orthopaedic surgeons spent so much money (compared with the cost of aspirin) without demonstrating the superiority of new anticoagulants? Nowadays, large-scale data, such as administrative governmental and clinical registries, are a powerful tool to answer questions, but only if there are answers to the questions. There is a difference between a scientific demonstration of effectiveness in the reduction of thrombophlebitis and pulmonary embolism and the scientific evaluation of effectiveness in the prevention of death by fatal pulmonary embolism. For the orthopaedic surgeon, the question remains simple: is it possible to predict and prevent a pulmonary embolism, particularly a fatal one? The prevalence of a fatal pulmonary embolism after hip arthroplasty is around 1.8% without prophylaxis and around 0.1% with any method of prevention4. Surgeons must remember that predicting the future remains difficult (even impossible). It is probably impossible to make a comparative scientific evaluation of the effectiveness of the prevention by 2 different treatments when the phenomenon is prevented. Clinicians use mortality statistics from the natural history of fatal pulmonary embolism and well-designed multicenter prospective studies of prevention using aspirin, anticoagulants, physical methods, or other drugs to change the natural history without increasing hematoma. A fair proportion of patients undergoing primary or revision arthroplasty are older than average. Underlying diseases and medications may contribute to the morbidity and mortality associated with the operation and pulmonary embolism. So, this prevention remains empirically a choice based on 2 assumptions: to use new methods to avoid death is to do good, and to use old methods suggests negligence. For many years, doing good appeared to be giving a new anticoagulation agent, which was more expensive, probably in the same way that doing good had been thought to be performing arthroplasty on young patients after that procedure became available. We know that the results of such thinking can sometimes be paradoxical. In an era of targeted therapy that is increasing health-care costs, aspirin is an old, inexpensive, and well-tolerated drug with a relatively low risk of excessive bleeding that, as proposed by Ludwick et al., may prove to be an effective agent to prevent venous thrombosis.
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Apr 19, 2023
Jan Stasko + 8
Open Access