Experimental Thromboprophylaxis with Low Molecular Weight Heparin After Microsurgical Revascularization

Abstract

There is great variability among microsurgeons as regards the use of prophylactic anticoagulant after revascularization and this is probably due to lack of comparative data. Also, there has been much debate regarding the benefit of anti-thrombotic therapies versus the risk of complications such as systemic bleeding and hematoma formation. To evaluate the effectiveness of postoperative low molecular weight heparin (LMWH) as a prophylactic anticoagulant therapy after microsurgical repair of the femoral artery and vein in rats. Randomized, blinded study. The femoral artery and vein of 40 Sprague Dawley rats were sectioned and repaired with microsurgical sutures under general anesthesia. They were randomly divided into 2 groups: Group (A) in which the 20 rats were injected with Enoxaparin subcutaneously at a dose 1.5 mg/kg once daily for 3 successive days; Group (B), the control group, in which 20 rats were injected with isotonic sodium chloride 0.9 % subcutaneously in a blinded fashion. After 7 days, the femoral vessels were re-explored and patency of the femoral vessels was assessed with empty-and-refill test. There were a total of 12 vascular thrombosis among 74 microsurgical repair in both groups with percentage of 16.22 % including, 5 arterial anastomosis and 7 venous anastomosis. The incidence of thrombosis in the treatment group (A) was 18.4 % while the incidence of thrombosis in the control group (B) was 13.8 %. This difference was not statistically significant using Fisher exact test. Postoperative administration of LMWH did not provide the desired protection against thrombosis after microsurgical vascular repair.

Mechanical Dilation of the Recipient Vessel with the DeBakey Vascular Dilator in Lower Extremity Reconstruction: A Report of Two Cases

“…In addition to intraoperative heparin administration and careful vessel manipulation, prophylactic use of low-molecular-weight-heparin after surgery can help prevent thrombus formation owing to possible intimal injury. [10][11][12][13] In free flap surgeries of the lower extremity, conventional manipulation with a forceps dilator alone is occasionally insufficient to restore the blood flow of the recipient vessel. Hence, if mechanical dilation of a long-range recipient vessel is required, a DeBakey vascular dilator can be used to overcome this limitation.…”

Towards standardization of training and practice of reconstructive microsurgery: an evidence-based recommendation for anastomosis thrombosis prophylaxis

“…It is a standard prophylactic measure for venous thromboembolism for patients undergoing major surgery or those undergoing more minor surgery with risk factors for VTE. LMWH has shown varying results in animal studies in its ability to prevent thrombosis formation at microvascular anastomoses and no clear benefit in clinical studies [35, 36]. …”

The Utility of Therapeutic Anticoagulation in the Perioperative Period in Patients Presenting in Emergency Surgical Department With Extremity Vascular Injuries

“…Patients with femoropopliteal injuries had systemic anticoagulation unless contraindicated with a varied rate of amputation including failed repair [24]. Ali Yousef et al described the insignificant effect of heparin in the prevention of microvascular surgery and be better by antiplatelet agents in femoral vessels in 20 rats experimentally [26]. Lang et al described the use of regional anticoagulation at the time of vascular repair with the amputation rate of 28% in 64 patients and was mostly due to vascular repair failure [27].…”