Deep Vein Thrombosis – A Preventable Complication
One of the biggest worries for anyone undergoing surgery is the chance of post-op complications. This is also a major worry of your surgeon.
One complication of major surgery, especially a long (greater than 2 hours) surgery, a recovery time that requires bedrest, or a procedure that requires a blood transfusion, is a deep vein thrombosis.
Deep vein thrombosis (DVT) is clotting of blood in a deep vein of an extremity (usually calf or thigh) or the pelvis. It is usually the primary cause of pulmonary embolism (PE) which is when the clot (thrombosis) travels to the lungs and immediately affects the breathing of the patient. DVT results from conditions that impair venous return, lead to endothelial injury or dysfunction, or cause hypercoagulability (blood more likely to clot easily). DVT may be asymptomatic or cause pain and swelling in an extremity. Symptoms of a PE are chest pain, shortness of breath and a decrease in the oxygenation of the blood.
There is always a chance of developing a DVT , so something must be done before, during and after surgery to prevent it. Long surgeries and recoveries are often unavoidable, so most hospitals and surgery centers have protocols set up.
Protocols generally include mechanical therapy (e.g. Compression devices or stockings, venous filters), and drug therapy.
Mechanical devices are SCD’s (Sequential compression devices) and these are the pumps that are wrapped around your calves and are on constantly during the surgery and recovery, when not ambulating. Venous filters are generally put in the patient’s vena cava (small invasive procedure usually done in the x-ray department) and “catch” any clots that may be headed for the lungs. This does not prevent DVT, but hopefully prevents a DVT from becoming a pulmonary embolism.
Drug therapy can include low dose unfractionated heparin (1 injection 2 hours preop and every 8-12 hours for 7-10 days or until ambulatory), low molecular weight heparins (more effective and much more expensive) or Fondaparinux (which is possibly more effective with orthopedic surgeries). People who are already on a blood thinner such as Warfarin are generally taken off that and put on the previous drugs as they make the chance of hemorrhage during surgery less likely. Warfarin would be restarted at least a day post-op once the chance of bleeding is low.
Early mobilization, leg elevation, compression devices, elastic stockings and anticoagulants are all recommended preventative measures. Patients who should not receive anticoagulants may benefit from the mechanical measures alone.