Primary prophylaxis of venous thromboembolism in surgical patients

Venous thromboembolism is a major risk for surgical patients during the perioperative period. Prevention of perioperative venous thromboembolism remains a critical component of surgical patient care. The risk for venous thromboembolism in surgical patients can be stratified by their risk factors and by the type of operation. Pharmacological prophylaxis for venous thromboembolism includes unfractionated heparin, low-molecular weight heparin, fondaparinux, warfarin, antiplatelet therapy, and direct thrombin inhibitors. Mechanical devices such as graduated compression stockings, intermittent pneumatic compressions, and venous foot pumps are also effective modalities for venous thromboembolism prophylaxis. The optimal preventive measure of venous thromboembolism should be based on the degree of risk for venous thromboembolism with the intensity of prophylaxis while balancing potential treatment benefits and risks in each individual patient. The epidemiology of venous thromboembolism, the methods for achieving venous thromboembolism prophylaxis, and the approach to institute venous thromboembolism prophylaxis in surgical patients undergoing various operative interventions are reviewed in this article.     

An overview of venous thromboembolism prophylaxis

This symposium reviewed the risk factors and problems associated with venous thromboembolism in surgical patients, especially those patients having total hip replacement. The importance of venous thromboembolism prophylaxis was emphasized by a theoretical analysis indicating that venous thromboembolism in patients having hip replacement not only saves lives but is also effective. A discussion of the pharmacology of low-molecular-weight heparin (LMWH) included a review of its role, clinically and experimentally, in venous thromboembolism prophylaxis. Three of the discussants presented their favorable experiences with LMWH in reducing the incidence of venous thromboembolism in patients having hip replacement. It can be concluded that LMWH does reduce the incidence of venous thromboembolism in patients having hip replacement without causing an increase in blood loss. If its effectiveness and safety remain substantiated, LMWH may soon become the preferred agent for venous thromboembolism prophylaxis.     

Pharmacological prophylaxis of venous thromboembolism in contemporary radical retropubic prostatectomy: Does concomitant pelvic lymphadenectomy matter?

The prevention of venous thromboembolism is a major concern in cancer patients undergoing pelvic surgery. Radical retropubic prostatectomy is a common treatment for localized prostate cancer and has been identified as a high risk procedure for postoperative venous thromboembolism. However, most patients diagnosed with prostate cancer in the current era have clinically localized, low volume disease and the risk of venous thromboembolism is very low. Multiple guidelines exist for the prevention of venous thromboembolism in patients undergoing radical retropubic prostatectomy and pharmacological venous thromboembolism prophylaxis is recommended. Most urological surgeons in the USA however, do not routinely utilize pharmacological prophylaxis. A major concern arises when radical retropubic prostatectomy is performed with a concomitant pelvic lymphadenectomy. Pharmacological prophylaxis is known to increase the rate of lymph drainage and the rate of lymphocele formation. Evidence suggests that lymphocele may be an independent risk factor for venous thromboembolism in the postoperative period. These factors raise concern over current guidelines calling for routine use of pharmacological venous thromboembolism prophylaxis in radical retropubic prostatectomy especially when lymphadenectomy is performed simultaneously.     

Insufficient duration of venous thromboembolism prophylaxis after total hip or knee replacement when compared with the time course of thromboembolic events: findings from the Global Orthopaedic Registry

Patients who have undergone total hip or knee replacement (THR and TKR, respectively) are at high risk of venous thromboembolism. We aimed to determine the time courses of both the incidence of venous thromboembolism and effective prophylaxis. Patients with elective primary THR and TKR were enrolled in the multi-national Global Orthopaedic Registry. Data on the incidence of venous thromboembolism and prophylaxis were collected from 6639 THR and 8326 TKR patients. The cumulative incidence of venous thromboembolism within three months of surgery was 1.7% in the THR and 2.3% in the TKR patients. The mean times to venous thromboembolism were 21.5 days (sd 22.5) for THR, and 9.7 days (sd 14.1) for TKR. It occurred after the median time to discharge in 75% of the THR and 57% of the TKA patients who developed venous thromboembolism. Of those who received recommended forms of prophylaxis, approximately one-quarter (26% of THR and 27% of TKR patients) were not receiving it seven days after surgery, the minimum duration recommended at the time of the study. The risk of venous thromboembolism extends beyond the usual period of hospitalisation, while the duration of prophylaxis is often shorter than this. Practices should be re-assessed to ensure that patients receive appropriate durations of prophylaxis.     

Current status of pulmonary embolism and venous thrombosis prophylaxis

Prophylaxis for venous thromboembolism is an area that has received intense study in certain conditions, but less than adequate coverage in other areas. In considering who needs prophylaxis, patients are categorized into levels of risk. Clinical venous thromboembolism can be correlated to these levels of risk. Methods of prophylaxis include pharmacologic, mechanical, and combinations of these. Each category of surgical and medical patient requires specific types of prophylaxis. In certain orthopedic indications, the length of prophylaxis outlasts the inpatient hospital stay and may be as long as 1 month after discharge. Even with the best prophylaxis today, the incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE) is decreased by only approximately 70% to 80%. Further developments should allow for greater declines in the rates of venous thromboembolism, with its subsequent short-term consequence of pulmonary embolism and lower extremity morbidity and long-term consequence of the disabling syndrome of chronic venous insufficiency (CVI).     

Heparin-induced thrombocytopenia after elective hip joint replacement with postoperative prevention of thromboembolism with low-molecular-weight heparin

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a severe side effect of the prophylaxis of venous thromboembolism with unfractionated heparin. The aim of the present study is to gain more information on the incidence of HIT during prophylaxis of venous thromboembolism with low-molecular-weight heparin in elective hip surgery. METHODS: 586 consecutive patients were included into the prospective study, who were admitted to hospital for elective hip replacement. The incidence of thrombocytopenia, clinically manifest venous thromboembolism and of the heparin-induced IgG antibodies were analysed during prophylaxis with low molecular-weight heparin. Patients received once daily subcutaneously low molecular-weight heparin for a mean of 28 days postoperatively. Platelet counts and clinical examinations for the presence of venous thromboembolism were done at days 0, 2, 7 (+/- 1) and 12 (+/- 2). Heparin-induced IgG antibodies were determined before and after a 12 (+/- 2) days prophylaxis with low molecular-weight heparin in 265 of 586 patients randomly. Patients were reexamined for thromboembolic complications after 3 and 6 months. The clinical suspicion of thromboembolic complication was documented objectively. RESULTS: None of the patients developed a decrease of platelets of < 50% of the initial value. Ten of 265 patients had elevated IgG antibodies against heparin/platelet factor 4 before prophylaxis (3.8%). After the 12 (+/- 2) days prophylaxis 13 of 265 patients had elevated IgG antibodies (4.9%). C14 serotonin assay was positive in 0 of 10 patients before treatment and in 3 of 19 patients at day 12 (+/- 2). Ten patients developed venous thromboembolism postoperatively (8 x deep venous thrombosis, 2 x pulmonary embolism, no fatal embolism). Only 1/19 patients with elevated antiheparin IgG titres developed venous thromboembolism. The C14 serotonin assay was negative in this patient. Two patients died in the postoperative phase due to underlying cardiovascular diseases. CONCLUSIONS: In patients with elective hip replacement prophylaxis of venous thromboembolism with low molecular-weight heparin was associated with a very low incidence of HIT, and hence screening for HIT antibodies is not required.     

Multimodal prophylaxis for venous thromboembolic disease after total hip and knee arthroplasty: current perspectives

Life-threatening in the short term and leading to a high level of morbidity in the long term, venous thromboembolism （VTE） is the most fearful complication following lower limb arthroplasty. With advances in surgical procedure, anesthetic management and postoperative convalescence have altered the risks of venous thromboembolism after total joint arthroplasty in the lower extremity.The pathogenesis of VTE is multifactorial and includes the well-known Virchow＇s triad of hypercoagulability, venous stasis and endothelial damage. Therefore, it is appropriate to use a multimodal approach to thromboprophylaxis. Despite extensive research, the ideal multimodal prophylaxis against venous thrombolism has not been identified. So this article reviews the recent developments in multimodal prophylaxis for thromboembolism after total joint arthroplasty.     

Prophylaxis of thromboembolism in general surgery: problems and perspectives

In 52169 patients, suffering surgical diseases of abdominal cavity and operated in the clinic along 17 years, the prophylactic measures for venous thrombosis and pulmonary thromboembolism were analyzed. Pulmonary thromboembolism have had occurred postoperatively in 0.3% of patients and venous thrombosis--in 7/5%. Specific prophylaxis was done in 54.7%. In 1990-2006 yrs the occurrence rate of pulmonary thromboembolism reduced among other lethality causes from 12.2 to 5.7%. The main problem issues concerning the venous thrombosis and pulmonary thromboembolism prophylaxis in general surgery are enlightened, the perspectives of their solving are determined.     

Venous thromboembolism prophylaxis

Venous thromboembolism is a common and frequent complication of hospitalized patients. Some venous thromboembolisms may be subclinical, while others present as symptomatic deep vein thrombosis and/or pulmonary embolism. Venous thromboembolism and pulmonary embolism contribute significantly to inhospital morbidity and mortality. The risk of venous thromboembolism is aggravated by dispositional and/or expositional risk factors. In patients at intermediate or high risk of venous thromboembolism, additional pharmacological thromboembolism prophylaxis becomes mandatory.     

Venöse Thromboembolieprophylaxe

Venous thromboembolism is a common and frequent complication of hospitalized patients. Some venous thromboembolisms may be subclinical, while others present as symptomatic deep vein thrombosis and/or pulmonary embolism. Venous thromboembolism and pulmonary embolism contribute significantly to inhospital morbidity and mortality. The risk of venous thromboembolism is aggravated by dispositional and/or expositional risk factors. In patients at intermediate or high risk of venous thromboembolism, additional pharmacological thromboembolism prophylaxis becomes mandatory.     

Prevention of venous thromboembolism in North America: Results of a survey among general surgeons

Purpose: The purpose of this study was to analyze current attitudes toward the prevention of postoperative venous thromboembolism among North American general surgeons.Methods: A survey regarding awareness of the problem of venous thromboembolism and preferred modalities of prophylaxis was sent to 3500 randomly selected Fellows of the American College of Surgeons.Results: A total of 1018 (29.1%) surveys was returned. Most of the responding surgeons consider venous thromboembolism a serious health problem. Ninety percent of the surgeons use prophylaxis against venous thromboembolism routinely. The most frequently used modalities are intermittent pneumatic compression, low-dose heparin, and elastic stockings. A combination of physical and pharmacologic methods is used by one fourth of respondents, and only 50% start pharmacologic prophylaxis before the surgical procedure. The thrombosis risk factors that are most frequently considered by surgeons when deciding about using prophylaxis are history of venous thromboembolism, immobility, and length of operation.Conclusions: North American surgeons who responded to this survey are well aware of the problem of venous thromboembolism and their approach to prevention has been significantly modified in the last 10 years. Compared with similar European surveys this survey reveals a higher implementation of physical methods such as intermittent pneumatic compression and elastic stockings. Because of the limited response rate and possibility of sampling bias, these findings should be interpreted with caution. (J VASC SURG 1994;20:751-8.)     

Venous thromboembolism prophylaxis in urology: A review

Venous thromboembolism is potentially a lethal problem, and is associated with chronic morbidity. Venous thromboembolism is frequently diagnosed after urological surgery, yet the role of perioperative venous thromboembolism prophylaxis is not clearly defined. Any current recommendations are largely based on evidence derived from other surgical specialties. Even within different guidelines, there remains significant variation, suggesting a consensus is required. The present review aims to define the problem of venous thromboembolism within the urological population, and identifies patients at risk. It evaluates the role of various types of mechanical and pharmacological prophylaxis, along with its timing and duration of administration in common urological operations. The current guidelines are summarized and compared in order to give the reader a better perspective of this vital condition.     

Venous thromboembolism prevention in surgery and obstetrics: clinical practice guidelines

BACKGROUND AND OBJECTIVE: To produce up-to-date clinical practice guidelines on the prevention of venous thromboembolism in surgery and obstetrics. METHODS: A Steering Committee defined the scope of the topic, the questions to be answered, and the assessment criteria. Eight multidisciplinary working groups (total of 70 experts) performed a critical appraisal of the literature in the following disciplines: pharmacology of antithrombotic agents, orthopaedics; general surgery (gastrointestinal (GI) and varicose vein surgery); urology; gynaecology and obstetrics; thoracic, cardiac and vascular surgery; surgery of the head, neck and spine; and surgery of burns patients. The resultant reports and guidelines were submitted for comment and completion of the Appraisal of Guidelines Research & Evaluation questionnaire to a total of 150 peer reviewers, before producing definite guidelines. RESULTS: The report answers the following questions for each type of surgery: (i) What is the venous thromboembolism incidence according to clinical and/or paraclinical criteria in the absence of prophylaxis? (with stratification of venous thromboembolism risk into low, moderate and high categories); (ii) What is the efficacy and safety of the prophylactic measures used? (iii) When should prophylaxis be introduced and how long should it last? (iv) Does ambulatory surgery affect efficacy and safety of prophylaxis? CONCLUSIONS: Apart from answering the above questions, the guidelines provide a summary table for each discipline. This table stratifies types of surgery into the three risk categories, specifies the recommended prophylaxis for venous thromboembolism (pharmacological and/or mechanical) and grades each recommendation. In addition, whenever appropriate, the recommended prophylaxis is adjusted to low- and high-risk patients.     

Editorial Commentary: Don't Worry About It—Hip Arthroscopy Is Safe From Venous Thromboembolism…Mostly Yes!

Data from a large national database report venous thromboembolism rates of 0.77% and 1.14% after hip arthroscopy at 30 and 90 days, respectively. Although this is very encouraging, risk stratification based on individual factors must be applied to determine in which patients it is best to administer venous thromboembolism prophylaxis after hip arthroscopy.     

Thrombosis prophylaxis in orthopedic surgery: current clinical considerations

Thrombosis prophylaxis in orthopedic surgery is an important consideration in order to avoid the morbidity and mortality of venous thromboembolism (VTE). Patients who do not receive prophylaxis, or receive inadequate prophylaxis, may be at risk for clinical or fatal pulmonary emboli, and a fatality, although rare, may be the first sign of a VTE. Although the surgeon may have corrected the patient's orthopedic problem, a symptomatic or asymptomatic venous thrombosis may become a new threat to the patient's quality of life. This problem places such patients at risk for recurrent VTE, as well as post-thrombotic syndrome, a progressive, lifelong disability. Methods of prophylaxis that prevent the most clots result in the fewest venous thromboembolic events, but no one method of prophylaxis is suitable for all patients. In order to select the appropriate modality, a careful risk assessment of each patient is necessary. Those at low or moderate risk levels do not require the same modalities that may be used in a patient with a previous history of thrombosis or with many risk factors. The purpose of this brief review is to examine the complications associated with venous thromboembolism and to discuss, in detail, the risk of thrombosis in orthopedic patients. In addition, thrombosis prophylaxis modalities are discussed and suggestions made based on current Chest Consensus Guidelines and FDA-approved products.     

Use of venous thromboembolism prophylaxis for surgical patients: a multicentre analysis of practice in Spain.

OBJECTIVE: To assess the use of venous thromboembolism prophylaxis in surgical patients. DESIGN: Retrospective multicentre study. SETTING: Eight acute-care teaching hospitals with more than 400 beds, Spain. PATIENTS: Medical records of all consecutive patients undergoing operations in the general surgical and trauma and orthopaedic services during the month of April, 1997, were randomly selected. INTERVENTION: The sample size for each type of operation (general, trauma-orthopaedic) was calculated from the number of operations done at each hospital (with an absolute precision of 5%, and an alpha error of 5%) and the prevalence of the use of venous thromboembolism prophylaxis obtained from a random sample of 50 records (25 from patients in general surgery and 25 from patients in orthopaedic surgery) from each centre. MAIN OUTCOME MEASURES: Appropriate and inappropriate pharmacological prophylaxis defined according to a combination of risk categories for venous thromboembolism, doses of antithrombotic agents given, time of starting prophylaxis, and its duration. RESULTS: A total of 1848 medical records (general surgery, n = 1025; trauma-orthopaedic surgery, n = 823) were included. Physical methods (elastic stockings, intermittent pneumatic compression) were used in only 0.3% of patients. Pharmacological prophylaxis consisted of low molecular weight heparin in 99% of cases. The percentage given heparin-based prophylaxis was 54%. Overall, appropriate prophylaxis was given in 1175 patients (64%). Use of thromboprophylaxis ranged from 27% to 70% among the participating hospitals. Prophylaxis was more likely to be appropriate in orthopaedic patients (577, 70%) than in general surgical patients (598, 58%) in both the high and moderate risk categories. CONCLUSIONS: Given the large variability between the participating hospitals, more specific protocols and recommendations about prophylaxis of thromboembolism in surgical patients are needed.     

Optimal duration of prophylaxis for venous thromboembolism following total hip arthroplasty and total knee arthroplasty

Elective total hip arthroplasty and total knee arthroplasty are associated with a high risk of postoperative venous thromboembolism. Traditionally, antithrombotic prophylaxis has been administered during the hospital stay. However, with patients spending less time in the hospital after surgery, there is a need to continue thromboprophylaxis beyond hospital discharge. The current recommendation for prophylaxis in total joint arthroplasty patients is a minimum of 10 days, with extended prophylaxis up to 28 to 35 days following total hip arthroplasty. Prophylaxis with low-molecular-weight heparins for approximately 4 weeks following hip arthroplasty has resulted in clinically significant reductions in the incidence of venographically confirmed deep vein thrombosis. Currently, no data support extended thromboprophylaxis beyond 10 days following total knee arthroplasty. Using weighted risk factors to assess individual risk for venous thromboembolism can help the physician determine the optimal duration of prophylaxis.     

Prophylaxis against venous thromboembolism in surgical patients

Venous thromboembolic disease is a common, potentially life-threatening, but preventable complication of surgery. Venographic studies have shown a high incidence of deep vein thrombosis in patients who do not receive prophylaxis. The long-term sequelae of deep vein thrombosis in these patients can be disabling, but the exact prevalence of post-thrombotic complications has not been well documented. Fatal pulmonary embolism has been reported in 0.5% to 1% of patients after major abdominal surgery and in 2% to 6% after total hip replacement. Several methods of prophylaxis against venous thromboembolism have demonstrated efficacy, but a surprising number of patients still do not receive prophylaxis. A medical record review in 16 hospitals recently disclosed that only 32% of high-risk patients received prophylaxis, with a range from 9% in a community hospital to 56% in a major teaching hospital. The possible reasons for this comparatively low rate of utilization are discussed. Current issues and future trends in the prophylaxis of venous thromboembolism are briefly summarized.     

Evidence-based practice in laparoscopic surgery: perioperative care

Best practices for reducing risks of postoperative infection, venous thromboembolism, and nausea and vomiting in patients undergoing laparoscopic surgery are uncertain. As a result, perioperative care varies widely. We reviewed evidence from randomized clinical trials on the effectiveness of interventions for postoperative infection, venous thromboembolism, and nausea and vomiting Data sources were the Cochrane Central Register of Clinical Trials, reference lists of published trials, and randomized clinical trials published in English since 1990. Trials were also limited to those focused on patients undergoing laparoscopic surgery. Data from 98 randomized clinical trials were included in the final analysis. Routine antibiotic use in laparoscopic cholecystectomy, and possibly other clean procedures not involving placement of prostheses, is likely unnecessary. Similarly, venous thromboembolism prophylaxis is probably unnecessary for low-risk patients undergoing brief procedures. Of a wide variety of methods for reducing postoperative nausea and vomiting, serotonin receptor antagonists appear the most effective and should be considered for routine prophylaxis.     

Deep vein thrombosis after elective knee surgery. An incidence study in 312 patients

The incidence of venous thromboembolism after elective knee surgery has previously been studied almost exclusively in patients receiving total knee replacements, in whom the risk of a deep vein thrombosis is approximately 60%. We report the results of ipsilateral ascending venography in 312 patients undergoing a wide variety of elective knee operations under tourniquet ischaemia, none of whom received any specific prophylaxis against thromboembolism. Total knee replacement was confirmed to carry a high risk with ipsilateral deep vein thrombosis in 56.4% and symptomatic pulmonary embolism in 1.9%. By contrast, arthroscopy was associated with a low incidence of venous thrombosis (4.2%). Meniscectomy, arthrotomy, patellectomy, synovectomy and arthrodesis were all high-risk procedures, particularly in patients over 40 years of age, and were associated with deep vein thrombosis rates of 25% to 67%. On the basis of these findings, we advise prophylaxis against venous thromboembolism in all patients over 40 years of age undergoing elective knee surgery other than arthroscopy.