Do Dilemmas Over DVT Prophylaxis Keep You Up At Night?
- Christopher F. Hyer DPM FACFAS
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As physicians, we try to do everything in our powers to heal and improve our patients’ quality of life. Medicine and surgery are part science/part art and some problems have no definitive answers.
Deep vein thrombosis (DVT) prophylaxis and foot and ankle surgery is one of my top clinical dilemmas and one I actively discuss with colleagues, fellows and residents. I would love to hear the online community’s thoughts as well.
If you operate on patients, you will have someone who develops a DVT. It is a given fact. We would all like the chances of DVT to be nil but that is impossible. Obviously, the more surgery you are involved in, the more DVTs you are going to see. That is just the numbers at work. Obviously, we would like to be as preventive as possible: screen for risk factors, take proactive preventive measures, etc. However, you cannot predict them all and even in the people you do suspect to be at risk, then what do you do?
There is limited data or guidance in the foot and ankle in regard to prophylaxis. The current DVT prophylaxis recommendations are from chest and abdominal surgery studies or from hip and knee data. Yet we all are treating postoperative patients with presumed risk factors including immobilization, bone surgery and diabetes.
Studies in the foot and ankle suggest postoperative DVT risk is relatively low at around 2 to 4 percent.1 A recent study of 1,172 Achilles ruptures only demonstrated a 0.43 percent risk for DVT and 0.34 percent for pulmonary embolism.2 An analysis by the English National Health Service looked at 45,949 ankle fractures, 33,626 metatarsal osteotomies and 1,633 total ankle replacements over a 42-month period.3 The DVT and pulmonary embolism risk in all groups was less than 0.5 percent with researchers concluding that prophylaxis is not required in most cases.
While the documented risk is extremely low in foot and ankle specific studies, there are currently no national guidelines or standards in regard to DVT prophylaxis for the foot and ankle surgeon.
As physicians, we obviously want to prevent any harm to patients when possible. We all have stories of patients who got DVTs, sometimes even after taking precautions.
How I Approach DVT Prevention
For me personally, all patients undergoing surgery take 325 mg enteric aspirin starting 24 hours after surgery and wear DVT compression stockings on the opposite leg starting in surgery. This protocol continues until the patient is freely ambulating without any motion-limiting device such as a cast or fracture boot. For patients who are at high risk (morbid obesity, history of previous clot, three or more risk factors such as diabetes, smoking, etc.), they have chemical anti-coagulation in the form of warfarin (Coumadin) or low molecular weight heparin plus use of the compression garment therapy. Likewise, this continues until patients are freely ambulating in shoe gear.
What is this based on? Well, again, there is limited guidance. I currently rely on my specific modifications of hip and knee recommendations. My modifications are also similar to the recommendations in a June 2011 statement by the American Academy of Orthopedic Surgeons (AAOS).4
Hardy, Roukis and Wukich and their respective colleagues have authored several good summaries of this dilemma in the foot and ankle.3,5,6
If you are still considering this problem too, I would like to hear your protocol and ///reasoning behind it. I would encourage you to read the AAOS link as well as the other foot and ankle resources.
1. Solis G, Saxby T. Incidence of DVT following surgery of the foot and ankle. Foot Ankle Int. 2002; 23(5):411-4.
2. Patel A, Ogawa B, Charlton T, Thordarson D. Incidence of deep vein thrombosis and pulmonary embolism after Achilles tendon rupture. Clin Orthop Relat Res. 2011 Nov 2 (epub ahead of print).
3. Hardy MA. Thromboembolic prophylaxis in foot and ankle surgery, what should we do? Foot Ankle Spec. 2011; 4(2):120-3.
4. Available at http://www.aaos.org/news/aaosnow/jun11/clinical10.asp .
5. Schade VL, Roukis TS. Antithrombotic pharmacologic prophylaxis use during conservative and surgical management of foot and ankle disorders: a systematic review. Clin Podiatr Med Surg. 2011; 28(3):571-88.
6. Wukich DK, Waters DH. Thromboembolism following foot and ankle surgery: a case series and literature review. J Foot Ankle Surg. 2008; 47(3):243-9.
Editor’s note: For additional info, be sure to read the upcoming January 2012 cover story for Podiatry Today as it will focus on DVT prophylaxis. For a related blog by Allen Jacobs, DPM, FACFAS, see http://tinyurl.com/cbav5kn .