Over the next few months, I will review topics from the most recent American Society of Plastic Surgeons’ Meeting in Toronto. A three hour block of time was devoted to a particularly important patient safety issue, Venous Thrombo Embolism (VTE). VTE is a catch all term to describe problems associated with blood clots after surgery.
The most common is deep venous thrombosis (DVT), a clot in the deep leg veins. Signs of DVT include calf pain and swelling. DVT is confirmed with an ultrasound of the legs called a duplex and it is treated with blood thinners. Although a local problem, DVT clots may break off and become a Pulmonary Embolism (PE). Long term, DVT may cause chronic leg pain, swelling, and even wound healing problems.
PE is one of the most feared adverse outcomes in surgery, especially in otherwise healthy Plastic Surgery patients. Blood clots in the lungs may cause serious breathing problems and may even lead to death. PE is notoriously difficult to diagnose as the symptoms may be vague and may be mistaken for less threatening post operative problems. The gold standard test is a CT angiogram which looks for clots in the lungs. A negative expensive test is much preferable to missing a PE.
VTE are treated with several months of anticoagulation (blood thinning). Patients are usually started on IV heparin or injected low molecular weight heparin (Lovenox most commonly) and then transitioned to oral coumadin. The blood test PT/INR is then followed frequently to make sure that the blood thinning is not too little (risking another clot) or too much (risking a bleeding episode).
The best approach, however, is to avoid the problem altogether. All patients under general anesthesia have sequential compression devices (SCD’s) and compressions stockings. This helps prevent blood from stagnating in the legs and forming blood clots while the patient is asleep. Some patients may be more prone to blood clots (hypercoagulable) and should be treated with Lovenox for a period of time around their surgery. Blood thinners are expensive and do risk unintentional bleeding after a surgery which may harm the result and even require a return to the operating room to treat the problem.
The big question we are all trying to answer is, “who should be treated with Lovenox, when, and how long?” The problem is that no one really knows. VTE is a rare enough event that studies with very large numbers of patients must be performed to get statistically meaningful information. That task is even harder in a specialized subset of plastic surgery patients. We do know that certain patients have greater risk than others for VTE. In the Plastic Surgery population, the most important ones are age, weight, history of cancer, family history of clotting, and length of surgery.
The Plastic Surgery leadership has proposed that we evaluate our patients with the Caprini risk assessment system and give them a score. Based on the score, we will then have guidelines on who to treat and for how long. The scoring system is well established, but the treatment guidelines are still being developed. Again, it is up to individual surgeon judgement.
What do I do? I score each patient in our electronic medical record (EMR) at the pre operative visit. Patients with higher scores and / or other contributing factors are started on Lovenox the day after surgery and usually continued for 10 days. Selected patients have specialized blood testing and even consultation with a hematologist (blood and cancer specialist). I counsel patients that there is a trade off between the risk of VTE and the cost, inconvenience, and bleeding risk associated with Lovenox use. Unfortunately, there are no standard of care guidelines, so I usually lean towards treatment. After all, it is easier to treat bleeding than it is a VTE.
Mark D. Wigod, MD, FACS – Cosmetic and Reconstructive Plastic Surgery
Serving Boise and Meridian as well as the Greater Treasure Valley and Southeast Idaho Region