Enhanced expression of bcl-2 inhibits apoptosis in cultured human keratinocytes

Intravenous heparin followed by oral warfarin sodium is effective for preventing recurrent thromboembolism in patients who have pulmonary embolism or proximal vein thrombosis. The effectiveness of intravenous heparin depends on obtaining an adequate anticoagulant response early during therapy. A validated heparin protocol should be used to ensure that an adequate anticoagulant response is obtained as soon as possible. Low molecular weight heparin has the practical advantage that it does not require monitoring and dose finding. If thrombolytic therapy is indicated, it is safer for many patients to base management on the noninvasive diagnosis rather than performing pulmonary angiography. In patients suspected to have pulmonary embolism who have nondiagnostic lung scan and adequate cardiorespiratory reserve, serial noninvasive leg testing is a practical approach that avoids pulmonary angiography, identifies patients who have proximal vein thrombosis requiring treatment, and avoids the risks of anticoagulant treatment in the majority of patients.     

PHLECO: a multicenter study of the fate of 1647 hospital patients treated conservatively without fibrinolysis and surgery

The PHLECO Study (phlebothrombosis conservative therapy) is a multicenter investigation of patients with deep vein thrombosis receiving conservative nonfibrinolytic hospital treatment. A second study (part II: PHLEFI, phlebothrombosis fibrinolytic treatment) to be published later deals with the outcome of fibrinolytic therapy. In both studies the incidence of life-threatening sequelae, such as pulmonary embolism, is of major interest. The 49 medical departments participating in the study mailed the relevant data to the Duisburg Coordination Center for further data analysis and the following information was gained: (a) In descending order of frequency, the clinical conditions of thrombosis were: immobility, postoperative status, malignancy, hormone treatment, posttraumatic conditions, and pregnancy. (b) In descending order of frequency, the sites of thrombosis were: femoral vein, calf vein, iliac vein, popliteal vein, and subclavian vein. Left-sided thrombosis predominated in the iliac and subclavian vein groups. (c) In descending order of frequency, the treatment regimens employed were: intravenous heparin+oral anticoagulants, intravenous heparin+subcutaneous heparin, intravenous heparin alone, subcutaneous heparin alone, intravenous heparin+subcutaneous heparin+oral anticoagulants, subcutaneous heparin+oral anticoagulants, intravenous heparin+platelet aggregation inhibitors. (d) The average hospital stay was 23.7 +/- 15.6 days. No correlation existed between duration of hospital stay and particular types of therapy. (e) The incidence of nonfatal pulmonary embolism was 16.1% while that of fatal pulmonary embolism was 2.33%. (f) Women outnumbered men in the group with fatal pulmonary embolism, and the death rate among older patients was higher than that among younger patients. (g) Patients with fatal pulmonary embolism had a shorter history of thrombosis than patients in the unselected cohort (patients with and without pulmonary embolism).(ABSTRACT TRUNCATED AT 250 WORDS)     

Peptide vaccination with an anchor-replaced CTL epitope protects against human papillomavirus type 16-induced tumors expressing the wild-type epitope

PURPOSE: Upper-extremity thrombosis appears to be more frequent today, comprising about 2% of all deep venous limb thrombosis. Its severity depends on the type of possible complications, i.e., pulmonary embolism and post-thrombotic sequelae. In this retrospective series, we investigated both the predisposing factors and the evolution of upper-extremity deep venous thrombosis. METHODS: Forty-nine consecutive patients (24 men and 25 women, mean age 50.2 years) with upper extremity deep venous thrombosis documented by color Doppler ultrasonography (n = 47) or phlebography (n = 2) were included in the study. RESULTS: Clinical manifestations were mainly pain (81.6%) and edema (93.9%). Mean time between the onset of clinical signs and diagnosis was 7.2 days. Thrombosis involved humeral (26.5%), axillary (46.9%), subclavian (73.5%) and jugular (24.5%) veins. Causative factors were malignancies (32.7%), venous catheters (22.4%), deep venous thrombosis related to effort or thoracic outlet syndrome (22.5%) and thrombophilic states (8.2%). During the 6-month follow-up, six patients developed symptomatic pulmonary embolism (12.2%); one recurrence (2.2%) and 19 post-thrombotic sequelae such as residual edema (36.7%) were also observed. Initial therapy included heparin administration, principally subcutaneous low molecular weight heparins (n = 36/49). CONCLUSION: This series highlights the fact that upper-extremity deep venous thrombosis is mainly secondary to either malignancies or catheterization. Moreover, it confirms that color Doppler ultrasonography may be useful in the diagnosis of the disease and also underlines the high frequency of severe complications, i.e., pulmonary embolism and post-thrombotic sequelae. Finally, this study also demonstrates that low molecular weight heparins should be considered as the initial treatment of choice.     

Sulfinpyrazone and postoperative deep vein thrombosis

Small doses of subcutaneous heparin and infusions of dextran both reduce the incidence of fatal pulmonary embolism after elective general surgery. But both methods have disadvantages. Therefore, the protection against deep vein thrombosis afforded by sulfinpyrazone, a drug which can be taken by mouth as well as by injection, was assessed in a prospective study of 119 patients undergoing elective general or urological surgery. The prophylactic administration of sulfinpyrazone was compared with the effects of small doses of sodium heparin and infusions of dextran-70. The 125I-fibrinogen test was carried out in all patients during their hospitalization. Deep vein thrombosis was diagnosed in 13 of 30 patients (43%) who received sulfinpyrazone, in 9 of 29 (31%) receiving dextran-70 and in 2 of 22 (9%) having subcutaneous heparin. The difference between the sulfinpyrazone and heparin groups was statistically significant (p less than 0.01). Sulfinpyrazone in the dose used in this trial was not effective in reducing the incidence of deep vein thrombosis during elective general surgery.     

Cost effectiveness of low-molecular weight heparin versus warfarin following hip replacement surgery

Little information is available on the efficacy of low-molecular-weight heparin (enoxaparin) versus warfarin for treatment of deep vein thrombosis and pulmonary embolism following hip replacement surgery. Still less is known of the comparative cost effectiveness of these two therapies. A retrospective study was done on 56 patients who underwent elective hip surgery at an urban medical center between 1991 and 1996. All patients received enoxaparin or warfarin for purposes of thromboprophylaxis. An analysis of medication cost, therapy, laboratory monitoring, and bleeding events of the two antithrombolytic agents was undertaken. Total savings with enoxaparin averaged $1253 per patient, or $137,886 over the study period. The incidence of deep vein thrombosis or pulmonary embolism was 0% with enoxaparin and 3% with warfarin. These data indicate that enoxaparin is a more cost-effective and efficacious regimen for thromboprophylaxis following hip replacement surgery than warfarin.     

The prevention of postoperative deep vein thrombosis and pulmonary embolism with low dose subcutaneous heparin and dextran

The standard low dose of heparin for the prevention of deep venous thrombosis in patients who are operated upon is 5,000 units administered subcutaneously two hours before operation and at eight or 12 hourly intervals for the next seven days. Heparin in low doses can at present be recommended as an effective agent in the prevention of deep venous thrombosis in patients over the age of 40 years who are undergoing a major abdominothoracic or gynecologic operation. There is reasonable evidence that heparin in low doses also offers a satisfactory protection against fatal pulmonary embolism for patients at high risk after general abdominothoracic operations. The evidence of the effectiveness of low doses of heparin in the prevention of deep venous thrombosis is less well established in other patients and particularly those at high risk, as after urologic and hip operations. This important distinction is to be made in terms of the population at risk and the efficacy of heparin in low doses. Considering the evidence so far available, it appears that the postoperative state in which dextran has been shown to reduce the incidence of phlebographically confirmed deep venous thrombosis most convincingly is after orthopedic operations. Major orthopedic operations are precisely the type in which the superiority of heparin in low doses is controversial. Unless proved otherwise, dextran 70 in an infusion of 500 to 1,000 milliliters of a 6 per cent solution started before operation and 500 milliliters the following and next three alternate days may be the agent of choice in preventing deep venous thrombosis in major orthopedic operations. Using this scheme, the prophylaxis of postoperative deep venous thrombosis appears equally effective with dextran 70 as with oral anticoagulants. Whether the protection offered by dextran 70 will also prevent fatal and nonfatal pulmonary embolism is still an open question. Low doses of heparin and dextran do not expose patients to serious risks of bleeding after operation, and with the recommended doses of the latter drug, other untoward effects are rare. At the doses recommended, neither of these two drugs requires laboratory monitoring.     

Panleukopenia

The influence of several diseases and conditions upon the prevalence of pulmonary embolism in autopsies performed during a ten year period at the University of Michigan has been analyzed. The major factors contributing to an increase in risk of development of pulmonary embolism include heart disease, certain types of cancer, obesity, acute paraplegia and accidental and operative trauma. These and several other risk factors defined in other studies should be used in a selective program designed to increase the rate of detection of deep venous thrombosis before pulmonary embolism occurs, or alternatively, patients at increased risk should receive prophylactic low dosage heparin therapy during hospitalization.     

Deep venous thrombosis and neoplastic pathology: our experience in emergencies

Deep vein thrombosis incidence is 1/1000 per year; it is associated with many risk factors which is considered as "thrombophilic states". Its pathogenesis is complex, caused by alterations of hemostasis system. Many studies have established the relation between cancer and subsequent venous thromboembolism, confirming the relationship of neoplastic cell interaction with coagulation system. Forty-seven patients admitted to the hospital from 1987 to 1996 with symptomatic clinically proved deep vein thrombosis were included in a retrospective study. Routine examination at the time of diagnosis of deep vein thrombosis revealed an occult cancer in 8 out of 47 patients; 9 out of 47 patients were admitted in hospital with vein thrombosis and known cancer. The aim of this study is to suggest the best, first treatment of vein thromboembolism in emergency to avoid the dangerous pulmonary embolism complication. The patients affected with deep vein thrombosis and cancer were elderly (over 70 years old, in mean); the neoplasia was of digestive system (8/17) in advanced metastatic stage there was cancer familiarity in 7 out of 47 patients. The high risk of pulmonary embolism associated to deep vein thrombosis suggests the importance of early starting the anticoagulant therapy and placing caval filter.     

Clinical diagnosis of deep venous thrombosis after hip replacement surgery

Hip replacement surgery is associated with a high frequency of postoperative deep vein thrombosis. This prospective study was performed in order to investigate if routine bedside questioning and examination by the visiting doctor could reveal deep vein thrombosis in the legs of patients who had received a hip replacement. 258 patients were evaluated. Thromboprophylaxis (dextran-70, low molecular weight heparin and graded elastic stockings) was given during the first week after operation. Bilateral venography was performed in all patients on day seven after operation, and showed an overall deep vein thrombosis incidence of 16%. The visiting doctors had not suspected deep vein thrombosis in any of the patients. This may have been because postoperative painful and swollen legs effectively masked any signs and symptoms of deep vein thrombosis. Our results show that deep vein thrombosis during the first week after hip replacement surgery cannot be discovered by clinical diagnostics. The high subclinical frequency of deep vein thrombosis indicates the importance of improving thromboprophylaxis in order to further minimise the occurrence of deep vein thrombosis and the risk of thromboembolic complications.     

Influence of compensated radioiodine therapy on thyroid volume and incidence of hypothyroidism in Graves'' disease

Postoperative thromboembolic complications were evaluated in 2578 patients undergoing elective abdominal surgery, all receiving prophylaxis with low molecular weight heparin. A positive fibrinogen uptake test (FUT) developed in 217 patients (8.4%), while 37 patients (1.4%) had major thromboembolism (TE, defined as proximal deep vein thrombosis and/or pulmonary embolism, verified with phlebography, pulmonary scintigraphy or autopsy). In only 14% a positive FUT was associated with a major TE event. In 19% of the patients with major TE the FUT was negative. In multiple logistic regression the independent predictors for major TE were partially different from those for positive FUT. Thirty day mortality was 3.0%. There were significant associations between both positive FUT and major TE on one hand and mortality on the other (relative risks 2.4 and 5.8, respectively). FUT is not a good predictor of major TE. Both positive FUT and major TE indicate a significant risk of postoperative death.     

The role of venous ultrasonography in the diagnosis of suspected deep venous thrombosis and pulmonary embolism

This paper describes the role of venous ultrasonography in the diagnosis of suspected deep venous thrombosis and pulmonary embolism. Inability to compress the common femoral or popliteal vein is usually diagnostic of a first episode of deep venous thrombosis in symptomatic patients (positive predictive value of about 97%). Full compressibility of both of these sites excludes proximal deep venous thrombosis in symptomatic patients (negative predictive value of about 98%). In patients with suspected deep venous thrombosis or in those who present with suspected pulmonary embolism but have a nondiagnostic lung scan, the subsequent risk for symptomatic venous thromboembolism is very low (<2% during 6 months of follow-up) provided that ultrasonography of the proximal veins remains normal in the course of 1 week (suspected deep venous thrombosis) or 2 weeks (suspected pulmonary embolism). Anticoagulation and further diagnostic testing can usually be safely withheld in these situations. Venous ultrasonography is much less reliable for the diagnosis of asymptomatic, isolated distal, and recurrent deep venous thrombosis than for the diagnosis of a first episode of proximal deep venous thrombosis in symptomatic patients. Clinical evaluation of the probability of deep venous thrombosis or pulmonary embolism, preferably by using a validated clinical model, complements venous ultrasonographic findings and helps to identify patients who would benefit from additional (often invasive) diagnostic testing. Thus, venous ultrasonography is thought to be a very valuable test for the diagnosis and management of patients with suspected deep venous thrombosis or pulmonary embolism.     

The phenylalanyl-tRNA synthetase specifically binds DNA

BACKGROUND: Clinical trials have been performed to compare with standard heparin a once or a twice daily regimen of low-molecular-weight heparin but no direct comparison has been done between these two low-molecular-weight heparin regimens in terms of efficacy and safety with a long-term clinical evaluation. METHODS: Patients with proximal deep vein thrombosis, confirmed by venography were randomly assigned to either nadroparin (10,250 AXa IU/ml) twice daily or nadroparin (20,500 AXa IU/ml) once daily for at least 5 days. Regimens were adjusted to bodyweight. Oral anticoagulants were started on day 1 or 2 and continued for 3 months. Patients were followed up for 3 months. The composite outcome of venous thromboembolism and death possibly related to pulmonary embolism was the primary measure of efficacy. Major bleeding was the principal measure of safety. The study was designed to show equivalence between the two regimens. RESULTS: Recurrent thromboembolic events or death possibly related to pulmonary embolism were reported in 13 patients in the once daily group (4.1%) and in 24 patients of the twice daily group (7.2%): (absolute difference 3.1% in favor of the once daily regimen; 95% confidence interval -6.6%, +0.5%). Major bleeding episodes during nadroparin treatment occurred in 4 (1.3%) and 4 patients (1.2%) in the once and twice daily groups, respectively. CONCLUSIONS: A nadroparin regimen of one injection per day is at least as effective and safe as the same total daily dose divided over two injections for the treatment of acute deep vein thrombosis.     

Expanding eligibility for outpatient treatment of deep venous thrombosis and pulmonary embolism with low-molecular-weight heparin: a comparison of patient self-injection with homecare injection

BACKGROUND: The outpatient treatment of patients with deep vein thrombosis and pulmonary embolism using low-molecular-weight heparin has the potential to reduce health care costs, but it is unclear if most patients with deep vein thrombosis and pulmonary embolism can be treated as outpatients. In the published studies, more than 50% of patients were excluded from outpatient treatment for reasons such as comorbid conditions, short life expectancy, concomitant pulmonary embolism, and previous deep vein thrombosis, and many patients were not treated entirely at home. We sought to determine if expanding patient eligibility for the outpatient treatment of deep vein thrombosis and pulmonary embolism affects the safety and effectiveness of the treatment, and to determine if patient self-injection compared with injections administered by a homecare nurse affected these outcomes. PATIENTS AND METHODS: We treated as outpatients all patients with deep vein thrombosis and pulmonary embolism, except for those with massive pulmonary embolism, high risk for major bleeding or an active bleed, phlegmasia, and patients hospitalized for reasons that prevented discharge. We compared 2 models of outpatient care to determine feasibility, safety, and efficacy. Both models involved nurse managers who provided daily patient contact and ongoing treatment; however, in one model the patients were taught to inject themselves and in the other model homecare nurses administered the injections. We expanded the population of patients eligible for outpatient treatment by including many patients not treated at home in previous studies. Most patients in our study were treated with dalteparin sodium, 200 U/kg every 24 hours, for a minimum of 5 days. Therapy with warfarin sodium was started on the day of diagnosis or the following day. Patients were followed up for 3 months to determine rates of recurrent venous thromboembolism, bleeding, and death. RESULTS: In this study, 194 (83%) of 233 consecutive patients were deemed eligible and treated as outpatients. Of the 39 patients who did not receive home therapy, 20 had concomitant medical problems responsible for their admission or were already inpatients, 6 had massive pulmonary embolism, 6 refused to pay for the dalteparin therapy, 4 had active bleeding, and 3 had phlegmasia cerulea dolens, which required treatment with intravenous narcotics for pain control. More than 184 (95%) of the 194 patients were treated entirely at home. There was no significant difference (P>.99) in the rate of recurrent venous thromboembolic events between the patients who were injected by homecare nurses (3/95 [3.2%]) and those who injected themselves (4/99 [4.0%]). Combining the 2 models, the overall recurrent event rate was 3.6% (95% confidence interval, 1.5%-7.4%). Similarly, there were no significant differences in rates of major hemorrhage (2/95 vs 2/99; P>.99), minor hemorrhage (8/95 vs 2/99; P = .06), and death (6/95 vs 8/99; P = .63). The overall rate of major hemorrhage was 2.0% (95% confidence interval, 0.6%-5.2%). CONCLUSIONS: We demonstrate that more than 80% of patients at our tertiary care hospital could be treated at home using 1 of the 2 models of care we describe. Our results demonstrate that patients can safely and effectively perform home self-injection under the supervision of a hospital-based nurse. Injections at home by a homecare nurse are similarly effective. Our overall rates of recurrent venous thromboembolism, bleeding, and death are at least as favorable as those previously reported despite using 1 dose per day of dalteparin for most patients.     

Analysis of immunoglobulin genes in splenic marginal zone lymphoma suggests ongoing mutation

BACKGROUND: The incidence of venous thromboembolism has not been well described, and there are no studies of long-term trends in the incidence of venous thromboembolism. OBJECTIVES: To estimate the incidence of deep vein thrombosis and pulmonary embolism and to describe trends in incidence. METHODS: We performed a retrospective review of the complete medical records from a population-based inception cohort of 2218 patients who resided within Olmsted County, Minnesota, and had an incident deep vein thrombosis or pulmonary embolism during the 25-year period from 1966 through 1990. RESULTS: The overall average age- and sex-adjusted annual incidence of venous thromboembolism was 117 per 100000 (deep vein thrombosis, 48 per 100000; pulmonary embolism, 69 per 100000), with higher age-adjusted rates among males than females (130 vs 110 per 100000, respectively). The incidence of venous thromboembolism rose markedly with increasing age for both sexes, with pulmonary embolism accounting for most of the increase. The incidence of pulmonary embolism was approximately 45% lower during the last 15 years of the study for both sexes and all age strata, while the incidence of deep vein thrombosis remained constant for males across all age strata, decreased for females younger than 55 years, and increased for women older than 60 years. CONCLUSIONS: Venous thromboembolism is a major national health problem, especially among the elderly. While the incidence of pulmonary embolism has decreased over time, the incidence of deep vein thrombosis remains unchanged for men and is increasing for older women. These findings emphasize the need for more accurate identification of patients at risk for venous thromboembolism, as well as a safe and effective prophylaxis.     

Outpatient management of deep vein thrombosis

OBJECTIVE: To assess whether patients with deep vein thrombosis (DVT) could be satisfactorily treated on an outpatient basis with low molecular weight (LMW) heparin and warfarin. DESIGN: A 22 month prospective study of adults attending St Peter's Hospital accident and emergency department with DVT. RESULTS: 1093 patients were referred and assessed; 160 were venogram positive, of which 159 patients between the ages of 22 and 89 years of age have now been treated with LMW heparin as outpatients. Direct liaison with community nurses has minimised the impact on general practitioner workload. CONCLUSIONS: 1272 bed days were saved during this period (an estimated 320,000 pounds). The outpatient treatment of thromboembolism has been shown to be effective and safe.     

Efficacy and safety of low molecular weight heparin in renal transplantation

BACKGROUND: Deep venous thrombosis (DVT) is a common problem with potentially devastating results in patients undergoing major surgical procedures. Certain renal transplant recipients are particularly at risk for allograft loss as a consequence of renal vein and artery thrombosis. Over the past few years, low molecular weight heparin has been well established as an accepted modality of treatment and prophylaxis of DVT. The efficacy and safety of low molecular weight heparin in the prophylaxis of DVT following renal transplantation in adults has not previously been reported. METHODS: Dalteparin was administered to 120 adult renal transplant recipients postoperatively at the Oregon Health Sciences University. RESULTS: No patient developed allograft arterial or venous thrombosis. One patient developed subclavian vein thrombosis. No bleeding complications were encountered, and side effects were very minimal. CONCLUSION: Prophylaxis with dalteparin is an effective and safe modality for the prevention of thrombosis in adult patients undergoing renal transplantation.     

Heparin-induced thrombocytopenia and thrombosis: presentation after cardiopulmonary bypass

Heparin-induced thrombocytopenia and thrombosis syndrome was diagnosed in a 63-year-old woman 11 days after coronary artery bypass grafting. Her only presenting complaints were incisional leg pain and vague chest discomfort. The syndrome was suspected when her platelet count was found to be 37,000/microL. A subsequent ventilation-perfusion lung scan showed findings highly probable for pulmonary embolism. An inferior venacavogram obtained before a pulmonary angiogram revealed a large retrohepatic thrombus at the right atrial junction. The patient was successfully treated with the defibrinogenating agent ancrod (Arvin). A diagnosis of heparin-induced thrombocytopenia and thrombosis syndrome should be considered and heparin therapy should be avoided in patients with low platelet counts who have been previously treated with heparin.     

The problem of the asbestos induced laryngeal carcinoma

A course of small doses of heparin given subcutaneously before and after elective operations has been reported to reduce the incidence of deep venous thrombosis and pulmonary embolism in general surgical patients. To test the safety of mini-dose heparin for neurosurgical patients, mini-dose heparin was used for 150 adult patients undergoing elective neurosurgical procedures. No operative complications were thought to be related to heparin administration. Postoperatively, there were four wound seromas, two hematomas, and one non-fatal pulmonary embolus. Seven patients died postoperatively, of whom five had no evidence of pulmonary embolus. Although no conclusions were drawn as to the effectiveness of mini-dose heparin in preventing deep venous thrombosis or pulmonary emboli, it was believed that the method could be used safely and without fear of increased intracranial or intraspinal bleeding for neurosurgical patients.     

Deep venous thrombosis in pregnant women

The main risk factors for deep vein thrombosis in pregnancy and after delivery are preeclampsia, operative delivery, adiposity, prolonged bed rest, and haemostatic defects (antithrombin, protein C and protein S deficiencies), activated protein C resistance, lupus anticoagulant/antiphospholipid antibodies. Hyperhomocystinaemia is a general risk factor for deep vein thrombosis. The clinical diagnosis of deep vein thrombosis is difficult and must be confirmed by imaging techniques. Positive D-dimer has high sensitivity, but low specificity to detect acute thrombosis. Standard treatment is unfractionated heparin intravenously for 7-10 days, followed by subcutaneous injections. Anticoagulant treatment is prolonged for 6-12 weeks after delivery, usually with warfarin. During pregnancies associated with high risk of thrombosis, low molecular heparin prophylaxis is given during pregnancy and 6-12 weeks after delivery. Thrombosis in pregnancy must be followed by adequate investigation for an underlying thrombotic predisposition.     

Risk factors for major thromboembolism and bleeding tendency after elective general surgical operations. The Fragmin Multicentre Study Group

OBJECTIVE: To elucidate those factors that contribute to the risk of major postoperative thromboembolism and perioperative bleeding tendency. DESIGN: Retrospective multiple logistic regression analysis. SETTING: 7 Scandinavian hospitals (6 Swedish and 1 Norwegian). SUBJECTS: 2070 patients undergoing elective major abdominal surgery. INTERVENTIONS: Patients were randomised to receive 2500 or 5000 XaI units of low molecular weight heparin daily. MAIN OUTCOME MEASURES: Major thromboembolism (proximal deep vein thrombosis confirmed by phlebography or necropsy, or pulmonary embolism confirmed by scintigraphy or necropsy, or both). Bleeding tendency (bleeding complications which were not explained by local haemorrhagic lesions or by coexisting disease). RESULTS: Previous thromboembolism, leg fracture or arthroplasty, present leg ulcer or malignant disease, operating time longer than 150 minutes, preoperative transfusion of 2 or more units, and preoperative hospital stay of 6 days or more (but not age, body weight, or varicose veins) were independent predictors for major postoperative thromboembolism. The risk was significantly increased with an increasing number of such risk factors. The risk of developing a diffuse bleeding complication was dependent on the dose of low molecular weight heparin, particularly in patients without risk factors. CONCLUSIONS: The use of a narrow definition of thromboembolism lead to a pattern of risk factors which was partly different from that found in previous studies, which were usually based on diagnosis with the 125I-fibrinogen uptake test.