Antithrombotic Therapy in Peripheral Arterial Occlusive Disease: Antithrombotic agents
No studies have established unequivocally a beneficial role of any of the antithrombotic agents in patients with acute embolic occlusion. The value of heparin treatment is uncertain, but most surgeons do administer heparin and continue the treatment throughout the perioperative period. If revascularization is delayed after an embolic or thrombotic event, thrombotic propagation from the site of occlusion often develops after a 6- to 8-h period. Heparin treatment may prevent or limit this process. The major role for anticoagulant therapy after embolization, however, is to prevent embolic recurrence. Evidence available from retrospective, nonrandomized studies (levels III and IV) suggests that anticoagulant therapy with heparin and/or oral anticoagulants reduces the frequency of recurrence by approximately 75% compared with no therapy. Reduced mortality was also observed following long-term anticoagulant therapy. The adverse effect of perioperative anticoagulant therapy in these studies was a substantially higher incidence of wound complications, particularly hematomas (up to 33%). Close monitoring and appropriate control of heparin given continuously after vascular operations can minimize bleeding complications. Others have noted no reductions in recurrent emboli and mortality with postoperative heparin treatment (level IV trial). To determine whether the benefits of postoperative anticoagulant therapy outweigh the risks, a randomized trial is necessary.
Thrombolytic therapy has been evaluated in numerous clinical trials involving patients with thrombotic or embolic occlusions Reading here buy zyrtec online. The initial approach was with systemic therapy using a priming dose of the thrombolytic agent to overcome inhibitors and to achieve an intense thrombolytic state in the circulating blood, which was sustained by constant IV infusion for periods ranging from a few hours to several days. In 10 uncontrolled studies (levels III and IV) in the early 1970s involving 1,800 patients, partial or substantial lysis was observed in approximately 40% and no discernible lysis was observed in the remaining 60%. Results were influenced by the duration of occlusion prior to treatment, with best results within 72 h of onset of symptoms, but much older lesions were shown to undergo lysis in some patients. No apparent difference was observed between the response of embolic or thrombotic lesions or the location of the occlusion or condition of the extremity before treatment was begun. Bleeding complications of serious magnitude were observed in approximately one third of the patients.