The condition of thromboembolic disease is one of the true ill-defined problems of orthopaedic surgery. The consequences of prophylactic treatment by means of anticoagulation can be wound hematomas, which, in turn, may lead to infections following total joint replacement. In the case of spinal surgery, the use of anticoagulation can result in the development of an epidural hematoma. On the other hand, the development of deep venous thrombosis can lead to a pulmonary embolism and death. Our problem, as surgeons, is the identification and treatment of patients who are at a greater risk for the development of deep venous thrombosis. Due to the serious nature of the disease, two sets of guidelines related to thromboembolic disease have been published in recent years. These include the Chest Guidelines1 and the American Academy of Orthopaedic Surgeons (AAOS) Clinical Practice Guidelines2. However, neither of these guidelines provides data that are useful for the spinal surgeon.
The real incidence and treatment of venous thromboembolism following spinal surgery is poorly reported in the literature. In a review article, published in 2008, Heck et al.3 reported on the incidence of venous thromboembolism in various subsets of patients with and without a variety of treatment modalities. However, in that review, it was concluded that low molecular weight heparin and intermittent use of pneumatic compression stockings were the treatment of choice in the immediate postoperative period for patients undergoing elective spinal surgery with venous thromboembolism risk factors or in the elderly population.
The authors of this paper, using strict inclusion and exclusion criteria, have done a thorough meta-analysis of the literature. They were able to identify fourteen studies that included a total of 4383 patients who met their selection criteria. They point out that this was an analysis of observational studies and not an analysis of randomized controlled clinical trials. Their study showed that the overall prevalence of deep venous thrombosis was 1.09% and that the prevalence of pulmonary embolism was 0.06%. In addition, the majority of findings of deep venous thrombosis were distal to the popliteal fossa. They point out that the recent published guidelines of the American College of Chest Physicians1 fail to strictly define recommendations for patients undergoing elective spinal surgery, but suggest the use of several different modalities, including low molecular weight heparin and intermittent pneumatic compression stockings, with additional recommendations for patients with one or more risk factors. Sansone et al. reported the morbidity associated with the use of pharmacological prophylaxis. This included eight epidural hematomas in patients receiving postoperative low-molecular-weight heparin.
The current study is timely. The authors provide a good review of the current literature and discuss the preventive treatment programs used for patients undergoing spinal surgery. Until there are better prospective data, the individual surgeon must weigh the risks and benefits of various methods of prophylaxis for each patient. This article helps put the magnitude of the problem into perspective.
The authors' take-home message is that more prospective studies are needed. In two different places in the Discussion section of their paper, they state that the changes to one's clinical practice should not be made on the basis of trends observed in this meta-analysis.
They feel, and I concur, that these studies should "seek to define the safety of various prophylactic modalities and to identify specific subpopulations of patients who are at greater risk for venous thromboembolism."
In summary, on the basis of the limited data as well as the lack of consensus data, I believe that this paper demonstrates that we must strongly advocate against treatment mandates for thromboembolism in spine surgery. There must be a consensus opinion and proper risk stratification of our patients to recommend a particular form of treatment.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
1. Geerts WH, Pineo GF, Heit JA, Berqvist D, Lassen MR, Colwell CW, Ray JG. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004;126(3 Suppl):338S-400S.
2. Johanson NA, Lachiewicz PF, Lieberman JR, Lotke PA, Parvizi J, Pellegrini V, Stringer TA, Tornetta P 3rd, Haralson RH 3rd, Watters WC 3rd. Prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Am Acad Orthop Surg. 2009;17:183-96.
3. Heck CA, Brown CR, Richardson WJ. Venous thromboembolism in spine surgery. J Am Acad Orthop Surg. 2008;16:656-64.