The incidence of venous thrombosis in the lower limbs following elective gallbladder surgery

Prevention of venous thromboembolism in general surgical patients. Results of meta-analysis

The results of randomized clinical trials evaluating commonly used methods of deep vein thrombosis (DVT) prophylaxis in moderate- and high-risk general surgery patients were pooled to obtain an unbiased estimate of efficacy and risks. Low-dose heparin (LDH), dextran, heparin-dihydroergotamine (HDHE), intermittent pneumatic compression (IPC), and graded elastic stockings significantly reduced the incidence of DVT; aspirin was ineffective. In contrast to other methods, elastic stockings have not been adequately studied to determine their value in reducing DVT in high-risk patients, such as those with malignancy. Only LDH and dextran were studied in numbers of patients sufficient for demonstrating a clear reduction in pulmonary embolism (PE). In comparison studies, LDH was superior to dextran in preventing DVT, but the two agents were equivalent in protecting against PE. Although HDHE was marginally better than LDH in preventing DVT, it appeared to have no advantage in preventing PE--at least in moderate-risk patients. The incidence of major hemorrhage was not increased with any of the prophylactic agents. However, wound hematomas occurred significantly more frequently with LDH, an effect noted in the pooled data from double-blind and open trials. In comparison trials with LDH, both dextran and HDHE had significantly fewer wound hematomas. LDH administered every 8 hours appeared more effective in reducing DVT than LDH administered every 12 hours; the incidence of wound hematomas was equivalent with both regimens.

Prediction and prophylaxis of postoperative thromboembolism--a comparison between peroperative calf muscle stimulation with groups of impulses and dextran 40

The effects of peroperative electrical calf muscle stimulation with groups of impulses giving a short lasting tetanus of the calf muscles on postoperative deep venous thrombosis (DVT) and pulmonary embolism (PE) were compared with that of dextran 40 given per and postoperatively. The incidence of DVT and PE during the first 4-6 postoperative days was recorded. The diagnosis of DVT was based on the 125I-fibrinogen uptake test and phlebography and of PE on pre- and postoperative perfusion pulmonary scintigram and chest X-ray examination. Both methods reduced the incidence of PE. Calf muscle stimulation reduced the DVT incidence in patients with malignant disease while the reduction in DVT incidence for the whole group only was significant in the stimulation as well as the dextran 40 group. Mean values for preoperatively determined levels of antithrombin III, beta-thromboglobulin, fibrinopeptide A, plasminogen and ability to release fibrinolytic activity during venous stasis did not differ between those patients who developed or those who did not develop postoperative DVT or PE. However, antithrombin III levels below 80 per cent appeared to predispose to postoperative thromboembolism. The two prophylactic methods have similar effects on the incidence of postoperative thromboembolism. The stimulation method has certain advantages due to its safety and simplicity.

Thrombosis after elective phlebography as demonstrated with the 125 I-fibrinogen test

The 125I fibrinogen test was used in 54 patients before and daily for 4 to 6 days after phlebography, for evaluating the incidence of post-phlebographic thrombosis. The indication for phlebography was in all cases varicose veins with perforators. A significantly increased fibrinogen uptake was found after phlebography in 4/54 patients in the calf, suggesting development of deep venous thrombosis, which, however, could not be confirmed with plethysmography or thermography. None had clinical signs of deep vein thrombosis. The rather low incidence of post-phlebographic thrombosis compared with other series is discussed.

Thrombosis following hip arthroplasty. A study using phlebography and 125I-fibrinogen test

Venous thrombosis after hip arthroplasty was studied using the 125I-fibrinogen test and phlebography. Eight out of ten dextran-treated and six out of ten control patients developed thrombosis. The thrombi were small and most frequently dorsal and dorso-lateral veins were involved. There were no thigh thrombi without concurrent calf thrombi. Half of the thrombi were found within the first postoperative week whereas the remainder occurred later. Preoperative venous pathology predisposed to postoperative thrombosis.