Postoperative deep vein thrombosis: identifying high-risk patients.

A prospective study was carried out to confirm the validity of a predictive index for patients at risk of developing deep vein thrombosis. The index, which correctly identified nine out of 10 patients and incorrectly identified seven out of 52 patients as being at risk, is based on five variable--namely, the euglobulin lysis time, serum concentration of fibrin-related antigen, age, percentage overweight for height, and presence of varicose veins. Thus a population of patients at particularly high risk of developing postoperative deep vein thrombosis may be identified preoperatively by means of this index, so that prophylaxis may be used more rationally.     

Failure of low-dose heparin to prevent significant thromboembolic complications in high-risk surgical patients: interim report of prospective trial. Groote Schuur Hospital Thromboembolus Study Group.

The efficacy of low-dose subcutaneous heparin (5000 IU eight-hourly) is being studied in a single-centre, prospective randomised trial of patients aged over 40 submitted to major elective intra-abdominal surgery. The trial end-points are the objectively defined incidence and extent of deep vein thrombosis (as seen on uptake of 125I-labelled fibrinogen, Doppler ultrasonography, and bilateral ascending phlebography) and non-fatal pulmonary embolus (as measured by preoperative spirometry and preoperative and postoperative chest radiography and perfusion lung scanning performed on a routine, unselected basis). An interim analysis of the first 200 patients indicates that low-dose heparin significantly reduces the incidence of calf-vein thrombosis but does not reduce the incidence of proximal segment thrombosis or non-fatal pulmonary embolism. Thus the routine use of low-dose heparin prophylaxis in all major surgical procedures in patients aged over 40 may not be advisable.     

Prevention of deep vein thrombosis after hip replacement: randomised comparison between unfractionated heparin and low molecular weight heparin.

OBJECTIVE--To evaluate the efficacy and safety of two subcutaneous prophylactic regimens for postoperative deep vein thrombosis after total hip replacement. DESIGN--Prospective open randomised multicentre trial. SETTING--28 European departments of orthopaedic surgery. INTERVENTION--All patients had bilateral phlebography 10 days after surgery. 31 patients receiving low molecular weight heparin and 29 receiving unfractionated heparin were excluded from the efficacy analysis for various reasons. PATIENTS--349 patients undergoing total hip replacement between September 1988 and May 1989. 174 patients received subcutaneously a low molecular weight heparin (Fraxiparine) with anti-factor Xa activity of 41 IU/kg/day for three days, then 62 IU/kg/day from day 4 to day 10. 175 patients received subcutaneous unfractionated heparin at intervals of eight hours; doses were adjusted to maintain the activated thromboplastin time at two to five seconds above control values. MAIN OUTCOME MEASURE--Total incidence of deep vein thrombosis and incidence of proximal deep vein thrombosis on bilateral phlebography. RESULTS--The total incidence of deep vein thrombosis was 16% in patients receiving unfractionated heparin and 12.6% in patients receiving low molecular weight heparin (p = 0.45), and the incidence of thrombosis of the proximal veins was 13.1% and 2.9% respectively (p less than 0.001). Four patients receiving unfractionated heparin and one receiving low molecular weight heparin developed pulmonary embolism. The incidence of bleeding complications was low and comparable in the two groups. CONCLUSION--Low molecular weight heparin is at least as effective as unfractionated heparin in preventing deep vein thrombosis and is more effective at preventing thrombosis of the proximal veins in patients undergoing hip replacement. Low molecular weight heparin is not more likely to cause bleeding complications and is simpler to give than unfractionated heparin.     

Preventing thromboembolism after myocardial infarction: effect of low-dose heparin or smoking.

A trial of low-dose subcutaneous heparin to prevent thromboembolic complications after myocardial infarction was carried out in 78 patients. Of the 37 heparin-treated patients only two (5%) developed evidence of leg vein thrombosis, while 14 (34%) of the 41 controls did so, and five controls developed pulmonary emboli. Leg vein thrombosis developed in 12 (50%) of the 24 controls who did not smoke cigarettes but in only two (13%) of the 17 controls who were cigarette smokers. Non-smokers who have a myocardial infarction should be given low-dose heparin subcutaneously to prevent leg vein thrombosis and pulmonary embolism.     

Subcutaneous injections and intravenous infusion of sodium salt of heparin in the treatment of thrombosis of deep veins of the lower extremities

Ninety-four patients with deep vein thrombosis of inferior limbs were randomly allocated to receive sodium heparin either by subcutaneous injections or by continuous intravenous infusion for six days. No significant difference was observed in the therapeutic efficiency as judged by phlebographic examinations and in rate of symptomatic pulmonary embolism between the two groups. There was one instance of major bleeding in the subcutaneous group. Minor bleedings occurred in 10 of the 48 patients treated with subcutaneous heparin and in 13 of the 46 patients receiving intravenous heparin. The results showed that subcutaneous injections of sodium heparin are as effective and safe as continuous intravenous infusion of this drug in the treatment of deep vein thrombosis.     

Prophylaxis of postoperative leg vine thrombosis by low dose subcutaneous heparin or peroperative calf muscle stimulation: a controlled clinical trial.

In a randomized, controlled clinical trial of two methods of preventing postoperative leg vein thrombosis patients undergoing major surgery were divided into three groups. One received intermittent electrical calf muscle stimulation during surgery, the second subcutaneous heparin calcium 5000 IU every eight hours for six days, and the third no specific prophylaxis. Leg vein thrombosis was detected by the 125-I-fibrinogen uptake test. Neither method was effective in patients undergoing open bladder or prostatic surgery. Stimulation did not reduce the incidence of leg vein thrombosis in patients with malignant disease undergoing laparotomy, but heparin calcium was highly successful in this group (P smaller than 0-001). When the laparotomy was for a benign condition, however, both heparin calcium (P smaller than 0-001) and stimulation (P smaller than 0-01) were effective.     

Failure of low-dose heparin to improve efficacy of peroperative intermittent calf compression in preventing postoperative deep vein thrombosis.

The possible benefits of adding a low-dose heparin regimen to the technique of peroperative intermittent calf compression for preventing deep vein thrombosis (D.V.T.) were assessed in a randomized trial in 84 surgical patients. The efficacy of peroperative intermittent calf compression was not enhanced by a low-dose heparin regimen, but neither was it worsened. Age, weight, duration, operation, and malignant disease did not affect the relative effectiveness of the two regimens of prophylaxis. The results confirmed that venous stasis is the principal cause of D.V.T.     

Dextran 70 in Prophylaxis of Postoperative Venous Thrombosis. A Controlled Trial

A controlled prospective trial was carried out in a group of 80 women undergoing gynaecological surgery and thought to be at risk of developing postoperative venous thrombosis. The patients, who had been randomly allocated to prophylaxis with either dextran 70 or warfarin, were well matched in age, weight and other predisposing factors.In the warfarin group, 12 out of 40 patients developed deep vein thrombosis, six of these episodes being classified as major and six as minor. In the dextran 70 group, 4 out of 40 patients developed deep vein thrombosis, all of them minor. The protective effect of dextran 70 is significantly better than that of warfarin (P<0·01) as used in the present study.     

Low-molecular-weight heparin and prevention of postoperative deep vein thrombosis.

The efficacy of low-molecular-weight heparin as a prophylactic agent was assessed in 150 consecutive patients over the age of 40 undergoing major abdominal surgery. Fifty of these patients received 1250 activated partial thromboplastin time (APTT) units of low-molecular-weight heparin every 12 hours: three developed isotopic deep vein thrombosis, which was confirmed by phlebography in two cases. The other 100 patients received a single injection of 1850 APTT units of low-molecular-weight heparin. Three of them developed isotopic deep vein thrombosis; phlebography failed to confirm the presence of thrombi in each case. None of the 150 patients studied died from fatal or contributory pulmonary emboli. Low-molecular-weight heparin was not associated with any increase in preoperative or postoperative bleeding. The effect of equal amounts of postoperative bleeding. The effect of equal amounts of low-molecular-weight heparin and unfractionated heparin on the coagulation mechanism during surgery was investigated in another 30 patients. The clotting assays and results of in-vivo platelet function tests indicated that both preparations produced similar effect. Intragroup comparisons, however, showed significant differences in the anti-factor Xa activity, lipoprotein lipase release, and plasma prekallikrein concentrations. A single injection of low-molecular-weight heparin daily is a convenient way of preventing deep vein thrombosis in high-risk patients undergoing major abdominal surgery.     

Thoughts about thromboembolic events prophylaxis in cancer patients

The risk of venous thromboembolic events (VTE) in cancer patients is higher than in the general population. Treatment may also increase this risk in these patients. Based on the appropriate criteria (of which the most important are the current ministerial guidelines) thrombosis prophylaxis should be started (given that there is no contraindication) on these patients and be continued while they are at risk. In the event of permanent risk thrombosis prophylaxis should be given lifelong. The drug of choice is low-molecular-weight heparin (LMWH) which is safer and more effective than the oral vitamin K antagonists. Platelet aggregation inhibitors have proved unsuccessful in this patient group. The evidence so far suggests that LMWH (during VTE prophylaxis) can have a positive impact on the course of cancer and perhaps it will be registered under the indication section for cancer patients in the future.     

Postural Abnormality as a Risk Marker for Leg Deep Venous Thrombosis in Parkinson’s Disease

Background

Pulmonary thromboembolism is a common cause of death in patients with autopsy-confirmed Parkinsonism. This study investigated the incidence of leg deep vein thrombosis in Parkinson’s disease and relationships between deep vein thrombosis and clinical/laboratory findings, including postural abnormalities as assessed by photographic measurements.

Methods

This cross-sectional study assessed the presence of deep vein thrombosis using bilateral leg Doppler ultrasonography in 114 asymptomatic outpatients with Parkinson’s disease.

Results

Deep vein thrombosis was detected in 23 patients (20%) with Parkinson’s disease. Deep vein thrombosis was located in the distal portion in 18 patients and in the proximal portion in 5 patients. No significant differences in age, sex, body mass index, disease duration, Hoehn-Yahr stage, anti-Parkinson’s drugs, or daily levodopa-equivalent dose were seen between deep vein thrombosis-positive and -negative groups. Univariate analysis for developing deep vein thrombosis in patients with Parkinson’s disease identified the following markers: long-term wheelchair use, bent knee, bent spine, and D-dimer elevation. Bending angles were significantly greater in the deep vein thrombosis-positive group at the knee and spine than in the deep vein thrombosis-negative group. Half of Parkinson’s disease patients with camptocormia had deep vein thrombosis. Among diabetes mellitus cases, long-term wheelchair use, bent knee over 15°, camptocormia, D-dimer elevation, the more risk markers were associated with a higher incidence of DVT. The presence of risk markers contributed to the development of deep vein thrombosis. On multivariate logistic regression analysis, a bent knee posture was strongly associated with an increased risk of deep vein thrombosis.

Conclusion

Presence of leg deep vein thrombosis correlated with postural abnormalities in Parkinson’s disease. We recommend non-invasive ultrasonographic screening for leg deep vein thrombosis in these high-risk patients with Parkinson’s disease.     

小剂量肝素治疗皮神经营养皮瓣术后静脉危象的探讨

目的：探讨小剂量肝素治疗皮神经营养皮瓣术后静脉危象的临床价值。方法：我院自2010年1月至10月共5例发生皮神经营养皮瓣术后皮瓣出现静脉危象。所有5例患者均在间断拆线的同时应用皮瓣皮下小剂量肝素注射使切缘持续缓慢渗血,并根据血运情况调整肝素使用剂量,观察皮瓣血运恢复情况及存活情况。结果：经小剂量肝素治疗后,5例皮神经营养皮瓣术后皮瓣颜色转红润,静脉危象均逐步缓解,全部皮瓣均成活,伤口无感染,愈合良好。患者对皮瓣外观和功能满意。结论：小剂量肝素皮下注射是一种简易但有效的解决皮神经营养皮瓣术后静脉危象的方法。     

Collaborative overview of randomised trials of antiplatelet therapy--III: Reduction in venous thrombosis and pulmonary embolism by antiplatelet prophylaxis among surgical and medical patients. Antiplatelet Trialists' Collaboration.

OBJECTIVE--To determine the efficacy of antiplatelet therapy as prophylaxis against deep venous thrombosis or pulmonary embolism in surgical and high risk medical patients. DESIGN--Overviews of all randomised trials of antiplatelet therapy that could have been available by March 1990 and in which deep venous thrombosis was assessed systematically. SETTING--53 trials (total 8400 patients) of an average of two weeks of antiplatelet therapy versus control in general or orthopaedic surgery; nine trials (600 patients) of antiplatelet therapy versus control in other types of immobility; 18 trials (1000 patients) of one antiplatelet regimen versus another. RESULTS--Overall, a few weeks of antiplatelet therapy produced a highly significant (2P < 0.00001) reduction in deep venous thrombosis. 25% of patients allocated antiplatelet therapy versus 34% of appropriately adjusted controls had deep venous thrombosis detected by systematic fibrinogen scanning or venography, representing prevention in about 90 patients per 1000 allocated antiplatelet therapy. There was an even greater proportional reduction in pulmonary embolism: such emboli were detected among 47 (1.0%) antiplatelet allocated patients versus an adjusted control total of 129 (2.7%), representing prevention among about 17 patients per 1000 treated (2P < 0.00001). In analyses confined to surgical trials, the proportional reductions were similar and separately significant for nonfatal pulmonary embolism (0.7% antiplatelet therapy v 1.8% control; 2P < 0.00001) and for deaths attributed to pulmonary embolism (0.2% v 0.9%; 2P = 0.0001). There was a slight but non-significant excess of deaths from other causes (1.0% v 0.7%), which made the difference in total mortality nonsignificant, though still favourable (1.2% v 1.5%). Information on adding antiplatelet therapy to heparin was limited but, at least for pulmonary embolism, suggested more protection from the combination than from heparin alone. The proportional reduction in the odds of suffering a deep venous thrombosis was roughly the same in patients having general surgery, traumatic orthopaedic surgery, and elective orthopaedic surgery (and in medical patients who were at increased risk of thromboembolism). For pulmonary embolism the numbers affected were smaller, but again the reductions were highly significant both in general surgery (16 (0.5%) v 58 (1.7%) pulmonary emboli; 2P < 0.0001) and in orthopaedic surgery (28 (2.7%) v 63 (6.1%) pulmonary emboli; 2P < 0.0002). CONCLUSION--It had previously been supposed that antiplatelet therapy did not influence venous thromboembolism, and many surgeons and physicians do not use it routinely for thromboprophylaxis, even for patients who are at substantial risk of deep venous thrombosis or pulmonary embolism. These results indicate that antiplatelet therapy--either alone or, for greater effect, in addition to other proved forms of thromboprophylaxis (such as subcutaneous heparin)--should be considered.     

骨科术后下肢深静脉血栓形成与超声弹性成像参数的相关性

摘要 目的：探讨骨科术后下肢深静脉血栓形成与超声弹性成像参数的相关性。方法：选取2021年6月~2022年6月在我院骨科进行诊治的术后下肢深静脉血栓患者80例为观察组,再选择同期术后健康者60例为对照组。比较两组超声弹性评分、应变值;采用Pearson检验分析超声弹性评分、应变值与肢深静脉血栓形成之间的相关性;采用多因素Logistic回归分析影响下肢深静脉血栓形成的独立危险因素;采用受试者工作特征曲线（ROC）分析超声弹性评分、应变值预测下肢深静脉血栓形成的价值。结果：观察组超声弹性评分、应变值均高于对照组（P＜0.05）。Pearson相关性检验显示,超声弹性评分、应变值与下肢深静脉血栓形成均呈正相关（r=0.785、0.826,P<0.05）。多因素Logistic回归分析结果显示,超声弹性评分、应变值是影响下肢深静脉血栓形成的独立危险因素（OR=4.632、4.768,P<0.05）。ROC曲线分析结果显示,超声弹性评分、应变值在预测下肢深静脉血栓形成中具有极高的价值。结论：随着下肢深静脉血栓的形成,患者超声弹性评分、应变值升高,该两项指标在预测下肢深静脉血栓形成中具有极高的价值,临床上可借助该两项指标的参数值对骨科术后下肢深静脉血栓形成进行预判。     

Subcutaneous calcium heparin versus intravenous sodium heparin in treatment of established acute deep vein thrombosis of the legs: a multicentre prospective randomised trial.

One hundred patients with phlebographically proved acute deep vein thrombosis of the legs were prospectively randomised into two treatment groups to compare the safety and efficacy of subcutaneous calcium heparin versus intravenous sodium heparin administered by constant infusion pump. The dose of heparin was determined by daily measurement of the kaolin cephalin clotting time. Treatment was maintained for up to 14 days, after which phlebography was repeated. Of 49 patients who received subcutaneous calcium heparin, two showed an increase in thrombus size, while eight showed complete lysis. In the 47 patients who received intravenous sodium heparin thrombus increased in size in 13 while only one showed evidence of complete lysis. These differences were significant. There were no significant differences between the two groups in the incidence of serious complications, although almost half of those receiving intravenous heparin had some minor problem with the constant infusion pump and just over half of those receiving subcutaneous heparin had some bruising at the injection site. This study showed that subcutaneous calcium heparin was more effective in helping lyse existing thrombus and preventing its propagation than intravenous sodium heparin.     

Diagnosis and treatment of venous thromboembolism by consultants in Scotland.

A questionnaire was sent to 508 consultants in Scotland likely to encounter deep vein thrombosis and pulmonary embolism to assess their current standard practice in diagnosis and treatment of these disorders. Replies were received from 358 (70.5%). In deep vein thrombosis 47% and in pulmonary embolism 33% of consultants usually depended on clinical observation alone for diagnosis. In deep vein thrombosis 37% used venography to supplement clinical diagnosis and in pulmonary embolism 13% used angiography and 53% used isotopic scanning. Almost all consultants treated deep vein thrombosis (95%) and pulmonary embolism (99%) with anticoagulants. Most consultants (81%) gave heparin by intravenous infusion. Although many consultants gave intravenous heparin for more than three days (49.5% in deep vein thrombosis and 61% in pulmonary embolism), 25% of these consultants did not use any laboratory monitoring of heparin''s effect. Large numbers of consultants gave warfarin for more than three months (20% in deep vein thrombosis and 47% in pulmonary embolism). There was a significant tendency to give heparin (p less than 0.01) and warfarin (p less than 0.001) for longer periods in pulmonary embolism than in deep vein thrombosis. This survey shows a widely varying practice and underlines the need for further controlled studies to provide clear guidance in the management of deep vein thrombosis and pulmonary embolism.     

Heparin in the Prevention of Deep Vein Thrombosis after Myocardial Infarction

A trial of continuous intravenous heparin in the prevention of deep vein thrombosis was undertaken in 48 patients who had suffered a myocardial infarction. Of the 24 control patients who did not receive heparin seven (29%) developed calf vein thrombosis as detected by the radioactive fibrinogen technique. None of the 24 heparinized patients had any evidence of venous thrombosis. This difference is significant at the 1% level.     

Effectiveness of long term oral anticoagulation treatment in preventing venous thrombosis in hereditary protein S deficiency.

In eight of 14 patients who were deficient in protein S and who belonged to two unrelated families thrombosis presented as thrombophlebitis in seven and deep vein thrombosis in six, complicated by pulmonary embolism in four and leg ulcers in two. In four patients superficial thrombophlebitis preceded deep vein thrombosis by one to 11 years. Post-thrombotic varicose veins and venous insufficiency had developed in four patients. In three of those and in a fourth patient symptomatic superficial thrombophlebitis, deep vein thrombosis, and pulmonary embolism did not recur while they were taking oral anticoagulant treatment for six to 12 years. The anticoagulation intensity corresponded to international normalised ratio values of over 2.5. It is concluded that the benefits of anticoagulant treatment for patients with congenital thrombotic disease are great, and thus it is necessary to make an early diagnosis and treat patients at risk of developing thrombosis.     

Dextran 70 in prophylaxis of thromboembolic disease after surgery: a clinically oriented randomized double-blind trial.

A randomized double-blind trial of prophylaxis of thromboembolism in surgical patients judged by clinical morbidity has been completed. Altogether 831 patients over 40 years of age who underwent elective surgery of the stomach, biliary system, or colon received either dextran 70 or normal saline before the operation. Thirteen of the 435 patients on saline and three of the 396 on dextran developed pulmonary embolism. Eight of these 16 patients died of pulmonary embolism--seven in the saline group and one in the dextran group. As detected either clinically or by 125I-fibrinogen scanning the incidence of deep vein thrombosis was similar in the two groups. There was no increased incidence of excessive bleeding in patients on dextran though clinical impression suggested that some patients on dextran bled excessively. This trial showed that dextran 70 administered by intravenous drip during operation is effective in preventing pulmonary embolism and, in particular, reducing mortality from this cause. It seems to be as effective as subcutaneous heparin but is easier to administer and places less of a burden on nursing services.