MIAMI BEACH – Women who develop a deep vein thrombosis while pregnant can safely undergo removal of the clot without jeopardizing their pregnancy, based on a recent experience with 11 cases at one U.S. center.
"Not many vascular surgeons are willing to perform thrombectomy in pregnant women, and most physicians fear thrombolytic therapy in pregnant patients," Dr. Anthony J. Comerota said at ISET 2012, an international symposium on endovascular therapy.
Dr. Anthony J. Comerota
But in reality, there is no evidence that thrombolysis poses any special risk during pregnancy, in part because the drugs that are usually used – urokinase, streptokinase, or tissue plasminogen activator (TPA) – do not cross the placenta, and therefore do not exert any fibrinolytic effect on a fetus, he said. In addition, the relatively recent introduction of pharmacomechanical methods for thrombolysis have "accelerated our enthusiasm and strengthened our confidence that this is an effective and safe strategy for treating extensive DVT [deep vein thrombosis] during pregnancy," said Dr. Comerota, a vascular surgeon and director of the Jobst Vascular Institute in Toledo, Ohio.
"Pregnancy need not be a major contraindication for successful management of extensive DVT. We need to minimize radiation, monitor the fetus, and control uterine contractions, but we should treat healthy, pregnant women [who have] a DVT the same way we treat healthy nonpregnant women" who have a DVT, he said in an interview. "The extraordinary concern for risk to the pregnancy [from clot removal] seems substantially overstated."
Because pregnancy produces a prothrombotic state, the risk that a healthy, pregnant woman has for DVT is about sixfold higher than her risk when not pregnant. Until now, most physicians deferred endovascular or surgical management of women who develop a DVT during pregnancy, and have relied exclusively on medical treatment with heparin or low-molecular-weight heparin, a strategy that is often ineffective.
"What pushed me to treat women earlier during their pregnancy was that I saw patients who did not receive therapy until after delivery, and by then the clot became more organized – a mix of collagen and scar inside the vein – -and caused severe postthrombotic disability," Dr. Comerota said.
Recently, he treated 11 pregnant women (10 with an iliofemoral thrombosis and 1 with the clot in her superior vena cava). One woman was in the first trimester, two were in the second, and eight were in the third trimester. Three patients underwent clot removal by open surgery, with the other eight treated by endovascular methods, including six who were treated with catheter-delivered TPA and one who received urokinase via catheter. Other endovascular tools that were used as needed included ultrasound clot treatment and rheolytic thrombectomy. In all cases, these treatments successfully removed the clot. One women developed hematuria and required a transfusion following her clot removal, and another patient developed a popliteal artery pseudoaneurysm. None of the patients had a recurrent DVT; two developed mild postthrombotic symptoms.
In one case, the fetus spontaneously aborted 5 days after the procedure secondary to antiphospholipid antibody syndrome, which had also triggered the thrombosis. The other 10 cases resulted in successful pregnancies and live deliveries, one surgically and the other nine vaginally. Three of the women had successful subsequent pregnancies, Dr. Comerota said.
Dr. Comerota said that he has been a speaker for and a consultant to Covidien, a company that makes some of the devices used in these procedures.