Prevention of deep-vein thrombosis in ambulatory arthroscopic knee surgery: A randomized trial of prophylaxis with low--molecular weight heparin

Thromboprophylaxis in routine arthroscopy of knee

BACKGROUND

Thromboprophylaxis in arthroscopy is controversial. Recent literature has shown variable rates of deep vein thrombosis following routine arthroscopic knee surgery; however, it is unknown if current practice reflects the literature. We have conducted a cross sectional survey to provide insight into the practice patterns perceived risks, benefits and barrier in the use of thromboprophylaxis.

MATERIALS AND METHODS

A 19 item survey was created regarding surgeons' use of thromboprophylaxis in their patients undergoing routine knee arthroscopy. E-mail surveys were sent out to members of the Canadian Orthopaedic Association.

RESULTS

Seventy-seven responses were obtained; of which 58.2% (n=45) of surgeons stated that they had a clinical interest in sports medicine, and 37.3% (n=29) had completed a fellowship in sports medicine or arthroscopy. Fifty five surgeons (71.6%) performed more than 40 arthroscopies per year. Prolonged surgical time was the only risk factor that would significantly increase their use of prophylaxis. Practice patterns surrounding the use of thromboprophylaxis were otherwise quite variable.

CONCLUSIONS

Our survey reveals that opinions and practice patterns surrounding the use of thromboprophylaxis following routine knee arthroscopy are diverse. This survey points out the need for larger well designed studies for concise guidelines.

Incidence of symptomatic venous thromboembolism after elective knee arthroscopy

BACKGROUND

Knee arthroscopy is the most commonly performed orthopaedic procedure in the United States and is usually considered to be a low-risk procedure. The purposes of this study were to describe the incidence of symptomatic deep venous thrombosis, symptomatic pulmonary embolism, and mortality after elective knee arthroscopy performed without thromboembolic prophylaxis, as well as to investigate the association of age, sex, procedure type, and oral contraceptive use with the odds of developing a venous thromboembolism.

METHODS

A retrospective cohort study of elective arthroscopic knee procedures during a twenty-seven-month period (January 1, 2006, through March 31, 2008) was performed with use of the administrative database of a large health maintenance organization. Use of ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) procedure codes for arthroscopic surgery identified 21,794 arthroscopic knee procedures. The occurrence of a symptomatic deep venous thrombosis or pulmonary embolism within ninety days after surgery was identified by reviewing administrative and electronic medical record data for inpatient, outpatient, urgent care, and emergency encounters. Mortality and the cause of death were captured with use of electronic medical records, Social Security Administration Death Master Files, and county death certificates. Patient charts were reviewed for confirmation of the deep venous thrombosis, pulmonary embolism, or death. Patients who had a history of a venous thromboembolism or who had received anticoagulation therapy within fourteen days prior to the index surgery were excluded.

RESULTS

The study cohort comprised 20,770 patients who met the inclusion criteria. Fifty-one patients (0.25%; 95% confidence interval, 0.18% to 0.31%) developed a deep venous thrombosis, and thirty-five (0.17%; 95% confidence interval, 0.11% to 0.22%) developed a pulmonary embolism. The incidence of venous thromboembolism was higher in patients who were fifty years of age or older (0.51% compared with 0.34% in younger patients), and the incidence in female patients was higher if they had been prescribed oral contraceptive medication (0.63% compared with 0.30% in female patients with no such prescription). No differences in the incidence of deep venous thrombosis or pulmonary embolism on the basis of sex or arthroscopic procedure code were noted. Nine patients (0.04%) died within ninety days of surgery, although only one death was confirmed to have resulted from a pulmonary embolism.

CONCLUSIONS

The ninety-day incidence of symptomatic venous thromboembolism after elective knee arthroscopy was relatively low, with a 0.25% incidence of deep venous thrombosis and a 0.17% incidence of pulmonary embolism. The overall ninety-day mortality after arthroscopic knee surgery was 0.04%.

Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

VTE is a serious, but decreasing complication following major orthopedic surgery. This guideline focuses on optimal prophylaxis to reduce postoperative pulmonary embolism and DVT.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

In patients undergoing major orthopedic surgery, we recommend the use of one of the following rather than no antithrombotic prophylaxis: low-molecular-weight heparin; fondaparinux; dabigatran, apixaban, rivaroxaban (total hip arthroplasty or total knee arthroplasty but not hip fracture surgery); low-dose unfractionated heparin; adjusted-dose vitamin K antagonist; aspirin (all Grade 1B); or an intermittent pneumatic compression device (IPCD) (Grade 1C) for a minimum of 10 to 14 days. We suggest the use of low-molecular-weight heparin in preference to the other agents we have recommended as alternatives (Grade 2C/2B), and in patients receiving pharmacologic prophylaxis, we suggest adding an IPCD during the hospital stay (Grade 2C). We suggest extending thromboprophylaxis for up to 35 days (Grade 2B). In patients at increased bleeding risk, we suggest an IPCD or no prophylaxis (Grade 2C). In patients who decline injections, we recommend using apixaban or dabigatran (all Grade 1B). We suggest against using inferior vena cava filter placement for primary prevention in patients with contraindications to both pharmacologic and mechanical thromboprophylaxis (Grade 2C). We recommend against Doppler (or duplex) ultrasonography screening before hospital discharge (Grade 1B). For patients with isolated lower-extremity injuries requiring leg immobilization, we suggest no thromboprophylaxis (Grade 2B). For patients undergoing knee arthroscopy without a history of VTE, we suggest no thromboprophylaxis (Grade 2B).

CONCLUSIONS

Optimal strategies for thromboprophylaxis after major orthopedic surgery include pharmacologic and mechanical approaches.

Is day surgery safe? A Danish multicentre study of morbidity after 57,709 day surgery procedures

BACKGROUND

Day surgery is expanding in several countries, and it is important to collect information about quality. The aim of this study was to assess morbidity and unanticipated hospital visits 0-30 days post-operatively in a large cohort.

METHODS

We prospectively recorded data from 57,709 day surgery procedures performed in eight day surgery centres over a 3-year period. We cross-checked with the National Patient Registry to identify complications 0-30 days post-operatively, and registrations from The Danish Register of Cause of Death were requested. We retrieved the records of 1174 patients to assign a relation between secondary contact and day surgery.

RESULTS

The overall rate of return hospital visits was 1.21% [95% confidence interval (CI): 1.12-1.30%] caused by a wide range of diagnoses. No deaths were definitely related to day surgery. The return hospital visits were due to haemorrhage/haematoma 0.50% (95% CI: 0.44-0.56%), infection 0.44% (95% CI: 0.38-0 49%) and thromboembolic events 0.03%. Major morbidity was rare. The surgical procedures with the highest rate of complication were tonsillectomies 11.4%, surgically induced abortions 3.13% and inguinal hernia repairs 1.23%.

CONCLUSION

This large-scale Danish national study confirmed that day surgery is associated with a very low rate of return hospital visits. Despite the rapid expansion of day surgery, safety has been maintained, major morbidity being very rare, and no deaths being definitely related to day surgery.

Applying trigger tools to detect adverse events associated with outpatient surgery

OBJECTIVE

The objective of this study is to evaluate the performance of 5 triggers to detect adverse events (AEs) associated with outpatient surgery. Triggers use surveillance algorithms derived from clinical logic to flag cases where AEs have most likely occurred. Current efforts to detect AEs have focused primarily on the inpatient setting, despite the increase in outpatient surgery in all health care settings.

METHODS

Using trigger logic, we retrospectively evaluated data from 3 large health care systems' electronic medical records. Patients were eligible for inclusion if they had an outpatient (same-day) surgery in 2007 and at least 1 clinical note in the 6 months after the surgery. Two nurse abstractors reviewed a sample of trigger-flagged cases from each health care system. After reaching interrater reliability targets (κ > 0.60), we calculated the positive predictive value (PPV) of each trigger and the confidence interval of the estimate.

RESULTS

The surgical triggers flagged between 1% and 22% of the outpatient surgery cases, with a wide range in PPVs (6.0%-62.0%). The pulmonary embolism and deep vein thrombosis and emergency department triggers had the lowest proportion of flagged cases along with the highest PPVs, showing the most promise for screening cases with a high probability of AE occurrence.

CONCLUSIONS

Triggers may be useful in identifying a narrow set of surgeries for further review to determine if a surgical AE occurred, complementing existing tools and initiatives used to detect AEs. Improved detection of AEs in outpatient surgery should help target potential areas for quality improvement.

Prevention of Venous Thromboembolism Using Enoxaparin in Day Surgery

We aimed to confirm the results of randomized, controlled trials on enoxaparin prophylaxis in unselected patients undergoing day surgery. The primary end point was the incidence of thromboembolic events during prophylaxis and up to 48 hours thereafter. A total of 11 794 patients, consisting of 52.1% male with mean age of 49.2 ± 15.7 were included. In all, 61.5% had no predisposing risk factors and 67.1% received no concomitant medication with the potential to increase bleeding. Patients were exposed to 20 mg (63.6%) and 40 mg (36.4%) of enoxaparin for a mean of 12.4 ± 9.8 days. Forty-four patients (0.39%) had confirmed symptomatic deep venous thrombosis and 1 patient confirmed pulmonary embolism. Bleeding occurred in 3.47% of patients (3.29% minor bleeding). Differences between 20 and 40 mg enoxaparin were negligible. Adverse drug reactions were experienced by 3.1% of patients. The present study results demonstrate that it is effective and tolerable to use a risk stratified dose of 20 or 40 mg enoxaparin in patients undergoing day surgery.

Pharmacologic prophylaxis for venous thromboembolism and 30-day outcomes among older patients hospitalized with heart failure: an analysis from the ADHERE national registry linked to Medicare claims

BACKGROUND

Hospitalized medically ill patients are at greater risk for venous thromboembolism (VTE). Although pharmacologic prophylaxis regimens have reduced VTE risk in medically ill patients, associations with early postdischarge adverse clinical outcomes among patients with heart failure are unknown.

HYPOTHESIS

We hypothesized that patients receiving pharmacologic VTE prophylaxis during hospitalization for heart failure would have lower rates of postdischarge adverse clinical outcomes than patients not receiving prophylaxis.

METHODS

Using data from the Acute Decompensated Heart Failure (ADHERE) registry linked to Medicare claims, we estimated 30-day postdischarge outcome rates for patients who received in-hospital subcutaneous heparin compared with patients who did not receive in-hospital VTE prophylaxis. We excluded patients who received warfarin or intravenous heparin. Outcomes included mortality, thromboembolic events, major adverse cardiovascular events, and all-cause readmission. We used propensity-score methods to estimate associations between VTE prophylaxis and each outcome. In a secondary analysis, we compared outcomes of patients receiving pharmacologic prophylaxis with unfractionated heparin (UFH) vs low-molecular-weight heparin (LMWH).

RESULTS

Of 36 799 eligible patients in 265 hospitals, 12 169 (33%) received pharmacologic VTE prophylaxis during the hospitalization. In unadjusted analysis and after weighting by the inverse probability of treatment, VTE prophylaxis was not associated with 30-day postdischarge mortality, thromboembolic events, major adverse cardiovascular events, or all-cause readmission. There were no differences in outcomes between patients receiving UFH and those receiving LMWH.

CONCLUSIONS

Pharmacologic VTE prophylaxis is provided to one-third of older patients hospitalized with heart failure. Treatment with LMWH or UFH did not have a statistically significant association with 30-day postdischarge outcomes.

[Prophylaxis of thromboembolic events in surgery. DVT prophylaxis: a comparison of out-patient and hospitalized patients]

BACKGROUND

The aim of this study was to compare the efficacy and tolerability of enoxaparin for preventing thromboembolism after surgery in the out-patient and in-hospital settings.

MATERIALS AND METHODS

A total of 2,005 out-patient and 1,360 hospitalized patients were included in the study. Prophylaxis was carried out with 20 or 40 mg enoxaparin and follow-up examination after 4-6 weeks.

RESULTS

Out-patients were younger (mean 48.4 vs. 58.5 years, p<0.01), had less cardiovascular comorbid diseases (7.1 vs. 20.8%, p<0.01) and underwent less complex interventions (arthroscopy 33.6 vs. 7.5%, p<0.01). Out-patients also received 20 instead of 40 mg enoxaparin more frequently (60.7 vs. 38.3%, p<0.01). The mean duration of thromboprophylaxis was reduced (12.6 vs. 15.3 days). For patients treated with 20 and 40 mg minor bleeding was observed in 1.8 and 3.4%, respectively (4.7 with 20 mg and 4.5% with 40 mg in hospital), major bleeding was 0.1% for both doses in out-patients and 0.0% with 20 mg and 0.3% with 40 mg in-hospital. Deep vein thrombosis (DVT) occurred in 0.4% of out-patients receiving 20 mg enoxaparin and 0.6% with 40 mg (0.0% with 20 mg and 0.9% with 40 mg in-hospital). There were no cases of pulmonary embolism (PE) in out-patients but PE was observed in 0.2% and 0.5% with 20 mg and 40 mg in-hospital patients, respectively.

CONCLUSIONS

Thromboprophylaxis with enoxaparin is well tolerated under clinical conditions as well as under out-patient treatment and severe bleeding complications are rare.

Strengths and limitations of standards of care to guide the orthopedic surgeon in VTE prevention

With respect to VTE prevention, several steps can be taken by orthopedic surgeons to ensure the best standard of patient care. All patients should be assessed for VTE risk and appropriate prophylaxis should be provided. Venous thromboembolism prophylaxis guidelines, hospital protocols, and risk assessment models can guide orthopedic surgeons in making individualized decisions. In cases where guidelines offer no direct recommendations, or disagree, standardized care may need to be tempered by clinical judgment and individual patient considerations. Improved health care and better outcomes can be achieved for orthopedic surgery patients by considering VTE prophylaxis from the viewpoint of the clinical guidelines and patient-specific factors.

Deep vein thrombosis and thromboprophylaxis in arthroscopic anterior cruciate ligament reconstruction

BACKGROUND

There is no clear evidence in the literature regarding the incidence of deep vein thrombosis (DVT) in patients undergoing arthroscopic anterior cruciate ligament (ACL) reconstruction. Literature also lacks on the recommendations on thromboprophylaxis in patients undergoing elective arthroscopic ACL reconstruction. We conducted a prospective analysis to assess incidence of DVT in patients undergoing arthroscopic ACL reconstruction.

MATERIALS AND METHODS

120 consecutive patients with MRI proven ACL injury who were operated for arthroscopic ACL reconstruction were enrolled in this prospective study. None of the patients had risk factors (on history) for DVT, and all were below the age of 45 years. All cases were operated upon by a single surgeon and a standard rehabilitation regime was followed. The patients underwent clinical examination and screening (Doppler ultrasonography/venous scan) for any DVT, on the day prior to surgery, day of discharge (Day 3) and at 4 weeks postsurgery. None of the patients received any form of thromboprophylaxis against DVT.

RESULTS

One hundred and twelve patients (61 males and 51 females) completed the study. The average age was 31.6 years (range 24-42 years). All patients underwent arthroscopic assisted ACL reconstruction surgery within 3 weeks of the injury. Two patients (males) in the series had Doppler venous scan proven DVT. One patient was asymptomatic but the screening Doppler picked up the DVT on the third postoperative day. The other patient was symptomatic at 12 weeks with pain and swelling in the leg and had ultrasound -proven DVT.

CONCLUSION

In our study the incidence of deep vein thrombosis in patients undergoing arthroscopic ACL reconstruction is 1.78%. We do not recommend routine thromboprophylaxis in patients, who are not high risk candidates for thrombosis and are of less than 45 years, in patients undergoing arthroscopic ACL reconstruction, with early postoperative rehabilitation.

Evidence-based patient safety advisory: liposuction

Liposuction is considered to be one of the most frequently performed plastic surgery procedures in the United States, yet despite the popularity of liposuction, there is relatively little scientific evidence available on patient safety issues. This practice advisory provides an overview of various techniques, practices, and management strategies that pertain to individuals undergoing liposuction, and recommendations are offered for each issue to ensure and enhance patient safety.

Incidence of venous thromboembolic disease following hip arthroscopy

Venous thromboembolic disease is a known complication of orthopedic surgery. Hip arthroscopy is a technically demanding procedure with a significant learning curve and low reported complication rate. Few reports document the incidence of venous thromboembolic disease following hip arthroscopy. Our hypothesis was that the incidence of venous thromboembolic disease following hip arthroscopy was comparable to that reported for knee arthroscopy. Eighty-one consecutive patients undergoing hip arthroscopy were retrospectively reviewed. All patients underwent standard diagnostic hip arthroscopy under traction of the operative leg against a well-padded perineal post. All procedures were performed on an outpatient basis. Three of 81 patients (3.7%) developed a clinically symptomatic venous thromboembolic disease in the postoperative period. The diagnosis was suspected clinically and confirmed with the use of a Doppler ultrasound. No patient developed symptomatic pulmonary emboli. One patient used oral contraceptives and 2 had no known risk factors for venous thromboembolic disease. All patients were successfully treated with anticoagulation. This is the first study to document multiple occurrences of venous thromboembolic disease following hip arthroscopy. This study demonstrated the incidence of symptomatic venous thromboembolic disease after hip arthroscopy to be 3.7%. Further study investigation is warranted regarding the incidence of symptomatic and asymptomatic venous thromboembolic disease following hip arthroscopy.

[Thromboembolism and its prevention in one-day surgery]

Perioperative antithrombotic prophylaxis as well as surgical and invasive procedures done in anticoagulated patients ("bridging") have primary importance as regards prevention of venous thromboembolism (VTE) and reducing haemorrhagic complications. It is understandable that overwhelming majority of publications are dealing with major surgery (when usually several days hospitalization is required) while much less papers focus on one-day surgery cases. In this paper a brief survey on VTE epidemiology and prevention is carried out based on the new international and the 4th Hungarian Antithrombotic Guideline. The new protocols suggest that beside general measures a perioperative pharmaceutical antithrombotic prophylaxis is necessary if concomittant inherited and/or acquired thrombophilia is present.

Thromboembolic complications after bilateral knee arthroscopic surgery patients

Deep venous thrombosis and pulmonary embolism are rare complications after arthroscopic knee procedures. Most of the cases of thromboembolic complications reported to have involved unilateral knee arthroscopic patients; here, we report the cases of patients with bilateral knee arthroscopy. The patients were treated with anticoagulants and thrombolytics and subjected to necessary laboratory monitoring. All the patients recovered well after the treatment and were symptom-free during a 6-month follow-up. The purpose of this article was to increase the awareness of knee arthroscopists of this complication.

[Perioperative thromboprophylaxis in adults]

According to the concept of Virchow, alterations of the blood flow, vascular injury and hypercoagulability of the blood (due to inherited or acquired thrombophilia or as a consequence of perioperative coagulation activation) are causally related to the risk of venous thrombosis. The overall risk of venous thromboembolic events in the perioperative setting ranges between <10% and >50%. The risk is highest in patients undergoing major orthopaedic surgery or cancer surgery. The aim of perioperative thrombosis prophylaxis is to reduce perioperative morbidity and mortality. The article discusses patient- and intervention-dependent thromboprophylactic measures. Recent recommendations for non-pharmacological and pharmacological prophylaxis are presented including the information on the beginning and duration of anticoagulation. Management strategies for patients undergoing abdominal and orthopaedic surgery as well as special aspects of the neurosurgical population and of cancer surgery are highlighted.

Clinical use of parnaparin in major and minor orthopedic surgery: a review

Patients undergoing arthroplasty or other orthopedic surgery show a high risk of venous thromboembolism (VTE), involving mortality, morbidity, and social costs; however, the risk for VTE in minor orthopedic surgery should not be underestimated and antithrombotic prophylaxis may be required. According to the literature, low-molecular-weight heparins (LMWHs) are more effective in preventing VTE than unfractionated heparins (UFHs) or vitamin K antagonists, and have a lower hemorrhagic risk. By comparing different prophylactic regimens, it has been shown that starting the prophylaxis near the time of the operation is the most critical point for efficacy, whether or not the first dose is administered pre- or post-operatively. Moreover, most thromboembolic complications are observed after discharge and, therefore, many clinicians advocate continuing prophylaxis for longer times (6–8 weeks) in order to further reduce the rate for VTE. The literature on parnaparin, a new LMWH, in VTE prophylaxis was reviewed. Parnaparin is equally effective as UFH, but it offers the advantages of a once-daily administration and improved tolerability, thus allowing the home management of patients with no need for laboratory coagulation tests.

Fatal pulmonary embolism in a polytraumatized patient following hip arthroscopy

Prophylaxis of venous thromboembolic disease for patients undergoing orthopedic procedures remains a controversial topic. Deep venous thrombosis and pulmonary embolism are well studied in the total joint arthroplasty population, as are the various options for prevention and treatment. In the past few years, hip arthroscopy has enjoyed increasingly broader indications and applications, especially in patients who have suffered trauma to the hip. Current studies of hip arthroscopy, however, have not reported venous thromboembolic disease as a complication. No guidelines exist for venous thromboembolic disease prophylaxis associated with hip arthroscopy, perhaps because the need for such guidelines has not materialized. This article describes a case of fatal pulmonary embolism associated with hip arthroscopy after traumatic injury. A literature review reveals that this is the first report of this complication and that no guidelines exist regarding prophylaxis of venous thromboembolic disease in hip arthroscopy. Surgeons performing this technique should make treatment decisions on an individualized basis, considering patient- and injury-specific factors.

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

BACKGROUND

Knee arthroscopy is a frequent surgical procedure. Arthroscopy procedures are considered minimally invasive. However, some patients will need extended surgical time, suffer injury and immobilization thus increasing the risk for thromboembolic events. Incidence of deep venous thrombosis (DVT) in patients undergoing knee arthroscopy is reported to be from 0.6% to 17.9% depending on the diagnostic method used. Different approaches are available for thromboprophylaxis (mechanical or pharmacological).

OBJECTIVES

To assess the effectiveness and safety of thromboprophylaxis to reduce the incidence of DVT in patients undergoing knee arthroscopy.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group Specialized Register (last searched October 2006) the CENTRAL (last searched Issue 4, 2006), MEDLINE (1966 to 2006), EMBASE (1980 to 2006), and Lilacs (1988 to 2006). We contacted specialists known to be involved in phlebology and interested in post thrombotic syndrome for details of unpublished and ongoing trials.

SELECTION CRITERIA

Randomized clinical trials (RCTs) and controlled clinical trials (CCTs), whether blinded or not (i.e. double blinded, single blinded or unblinded) of all type of interventions, whether mechanical or pharmacological, single or in combination, used to prevent DVT in males and females over 18 years old undergoing knee arthroscopy. There was no restriction on language.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Four trials involving 527 predominantly male participants were included. The main weakness of the studies was the lack of correct stratification of the arthroscopic intervention.The relative risk (RR) of thrombotic events was 0.16 (95% confidence interval (CI); 0.05 to 0.52) comparing any type of low molecular weight heparin (LMWH) versus placebo. All thrombotic events but one (pulmonary embolism in the LMWH group) were distal venous thrombosis. Adverse events were most common in the intervention group than in the control group, RR 2.04 (95% CI 1.21 to 3.44). There were 66 episodes of adverse events. The number needed to harm was 20 for any adverse events.

AUTHORS' CONCLUSIONS

This meta-analysis suggests that LMWH reduces the incidence of distal DVT diagnosed by sonogram. The clinical benefit of this is uncertain. No strong evidence was found to conclude thromboprophylaxis is effective to prevent thromboembolic events and safe, in people with unknown risk factors for thrombosis, undergoing knee arthroscopy.

Venous thromboembolism in lower extremity arthroscopy

Venous thromboembolism (VTE) is a relatively rare complication of arthroscopic surgery of the lower extremity, but it does have the potential to result in significant morbidity and possible mortality. VTE has been reported to occur with knee arthroscopy, and guidelines for VTE prophylaxis before and after knee arthroscopy have been proposed. There are much fewer data regarding the incidence of VTE occurring after arthroscopy of the ankle and the hip. This article reviews the literature on the incidence, treatment, and prevention of VTE in association with arthroscopy of the lower extremity.

Outpatient-Based Primary and Secondary Thromboprophylaxis With Low-Molecular-Weight Heparin

Although oral vitamin K antagonists such as warfarin have been the mainstay of thromboprophylaxis in the outpatient setting, warfarin has potential disadvantages, including food and drug interactions, the need for drug monitoring, intolerance, failure, and hypersensitivity syndromes. The use of low-molecular-weight heparin as a primary or secondary thromboprophylactic drug in the outpatient setting for extended prophylaxis or as outpatient bridging therapy has been addressed less extensively. Available evidence shows that low-molecular-weight heparin can be used as extended outpatient-based primary thromboprophylaxis for major orthopedic and cancer surgery and is a safe and effective alternative to warfarin in long-term secondary thromboprophylaxis, especially in cancer patients and in pregnant women. Low-molecular-weight heparin can also be used as an alternative to unfractionated heparin as outpatient-based bridging therapy. In addition to good clinical outcomes and financial benefits, mainly resulting from a reduction in the length of hospital stay, the use of extended-duration low-molecular-weight heparin in the outpatient setting appears to be feasible, with high patient compliance.

Prophylaxis of venous thromboembolism in minor orthopedic surgery with parnaparin

This study analyzed the efficacy of venous thromboembolism prophylaxis in knee arthroscopy in 509 patients who received Parnaparin (Alfa Wassermann, Bologna, Italy), 3200 IU to 4250 IU daily, after minor arthroscopic knee surgery. No proximal deep venous thrombosis or other thromboembolic events occurred. Adverse events related to the treatment with Parnaparin were observed in 2 of 172 patients treated with 3200 IU/d and in 6 of 337 patients treated with 4250 IU/d, without any evidence of dose-proportionality in the incidence. Prophylaxis with a low-molecular-weight heparin such as Parnaparin should be considered in all patients who will be undergoing a procedure in which a tourniquet is used. If Parnaparin is used, it should be started immediately after knee arthroscopy at doses of 3200 to 4250 IU/d, according to the characteristics of the patients. Depending on the patient's risk factors, postoperative prophylaxis for 10 days may be appropriate.

Extended-duration thromboprophylaxis with enoxaparin after arthroscopic surgery of the anterior cruciate ligament: a prospective, randomized, placebo-controlled study

PURPOSE

To compare the efficacy of extended-duration thromboprophylaxis with enoxaparin for 20 days in the outpatient setting with in-hospital thromboprophylaxis with enoxaparin (3 to 8 days) only in patients who had undergone arthroscopic surgery of the anterior cruciate ligament (ACL).

METHODS

This was a single-center, randomized, double-blind, prospective trial investigating 175 ACL surgery patients. All patients received subcutaneous enoxaparin 40 mg once daily 12 to 18 hours presurgery and 3 to 8 days postsurgery during hospitalization. After discharge, patients were randomized to 40 mg enoxaparin (n = 87) or placebo (n = 88) self-administered once daily subcutaneously for 20 days. The primary efficacy end-points were the incidences of symptomatic and asymptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE). Primary safety endpoints were the incidences of major and minor bleeding.

RESULTS

Thirty-five patients were excluded because of noncompliance with the predefined protocol. No patient had DVT confirmed by magnetic resonance venography (MRV) at discharge. Of 140 patients in the intention-to-treat population, 2 (2.8%) who received postdischarge enoxaparin (n = 72) and 28 (41.2%) who received placebo (n = 68) had DVT confirmed by MRV (P < .001). No patients were diagnosed with PE. No major bleeds occurred. Minor bleeding occurred in 13 (2.5%) out of 513 postdischarge enoxaparin injections and 10 (2.0%) out of 492 placebo injections (P = .595). Risk factors for DVT during the 20 days postdischarge were age >30 years (odds ratio [OR]: 3.241; 95% confidence interval [CI], 1.015 to 10.349) and immobilization before surgery (OR 18.195; 95% CI, 2.046 to 161.837).

CONCLUSIONS

Extended-duration postdischarge thromboprophylaxis for 20 days with enoxaparin in the outpatient setting significantly reduced the incidence of DVT in ACL surgery patients compared with enoxaparin limited to in-hospital thromboprophylaxis without increasing major or minor bleeding.

LEVEL OF EVIDENCE

Level I, high-quality randomized controlled trial.

Interventions for preventing venous thromboembolism in adults undergoing knee arthroscopy

BACKGROUND

Knee arthroscopy is a frequent surgical procedure. Arthroscopy procedures are considered minimally invasive. However, some patients will need extended surgical time, suffer injury and immobilization thus increasing the risk for thromboembolic events. Incidence of deep venous thrombosis (DVT) in patients undergoing knee arthroscopy is reported to be from 0.6% to 17.9% depending on the diagnostic method used. Different approaches are available for thromboprophylaxis (mechanical or pharmacological).

OBJECTIVES

To assess the effectiveness and safety of thromboprophylaxis to reduce the incidence of DVT in patients undergoing knee arthroscopy.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group Specialized Register (last searched October 2006) the CENTRAL (last searched Issue 4, 2006), MEDLINE (1966 to 2006), EMBASE (1980 to 2006), and Lilacs (1988 to 2006). We contacted specialists known to be involved in phlebology and interested in post thrombotic syndrome for details of unpublished and ongoing trials.

SELECTION CRITERIA

Randomized clinical trials (RCTs) and controlled clinical trials (CCTs), whether blinded or not (i.e. double blinded, single blinded or unblinded) of all type of interventions, whether mechanical or pharmacological, single or in combination, used to prevent DVT in males and females over 18 years old undergoing knee arthroscopy. There was no restriction on language.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Four trials involving 527 predominantly male participants were included. The main weakness of the studies was the lack of correct stratification of the arthroscopic intervention. The relative risk (RR) of thrombotic events was 0.20 (95% confidence interval (CI); 0.07 to 0.57) comparing any type of low molecular weight heparin (LMWH) versus placebo. All thrombotic events but one (pulmonary embolism in the LMWH group) were distal venous thrombosis. Adverse events were most common in the intervention group than in the control group, RR 2.11 (95% CI 1.26 to 3.55). There were 66 episodes of adverse events. The number needed to harm was 20 for any adverse events.

AUTHORS' CONCLUSIONS

This meta-analysis suggests that LMWH reduces the incidence of distal DVT diagnosed by sonogram. The clinical benefit of this is uncertain. No strong evidence was found to conclude thromboprophylaxis is effective to prevent thromboembolic events and safe, in people with unknown risk factors for thrombosis, undergoing knee arthroscopy.

An unusual case of pulmonary embolism after arthroscopic meniscectomy

Although the incidence of pulmonary embolism (PE) following arthroscopic knee surgery has not been well established, such occurrences place the patient at high risk. In this report we present a case of PE following arthroscopic meniscectomy. The patient was a 63-year-old woman, with no definite risk factors for PE, who underwent successful arthroscopic meniscectomy. However, on the postoperative 9th day she developed dyspnea and tachycardia. Investigations carried out in the emergency department, including EKG, echocardiography, and CT angiography, supported the diagnosis of a PE. Heparin therapy was initiated, and the patient's condition then improved sufficiently to allow follow-up at our outpatient department.

Complications in knee arthroscopy

All simple arthroscopic procedures during 1999 through 2001 performed at Baerum community hospital were retrospectively examined. Procedures were excluded when being part of more complex procedures. A total of 876 procedures performed on 785 patients were left for examination. Complications were registered from the patient record and all received a written questionnaire or phone call. The answer was obtained from 97.6%. The overall complications rate was low, giving total of 5.00%. A total of 0.68% of the complications had therapeutic consequences. There were two superficial infections, one thromboembolic event/pulmonary embolus and one reoperation due to scar tissue. Other complications were considered minor, and had none or little consequence for the patient comprising preoperative bradycardial episodes, asthmatic events, subcutaneous infusion of total intravenous anaesthetics (TIVA), instrument breakage and conversion to arthrotomi. Postoperatively registered complications included swelling, haemarthros, portal bleeding and fistulation, temporary sensory loss and longstanding pain. Duration of surgery was the only predicting factor for postoperative complications. Simple arthroscopic surgery is safe and has few serious complications. The use of TIVA or tourniquet does not increase the morbidity or complication rate, and prophylaxis against thromboembolism was not necessary.

Prévention de la maladie thromboembolique en orthopédie et traumatologie

Orthopaedic and trauma surgery are classified according 3 groups of venous thromboembolic risk. Elective total hip replacement (THR) or total knee replacement (TKR), hip fracture surgery or trauma patients are at high risk. Isolated lower extremity injury with fracture is at moderate risk whereas this risk is low without fracture as well as with knee arthroscopy. In THR and TKR, low molecular weight heparin (LMWH), fondaparinux or melagatran-ximelagatran are strongly recommended. The routine use of other anticoagulants, in particular vitamin K antagonist are not recommended. In patients at high risk of venous thromboembolism as for example trauma patients, optimal use of intermittent pneumatic compression is an alternative option in case of contra-indication to anticoagulant prophylaxis. Graduated compression stockings enhance the efficacy of pharmacological methods. In schedule surgery, initiation of prophylaxis with LMWH may be started postoperatively. To reduce the haemorrhagic risk of anticoagulants, timing of first postoperative dose is essential and is proper to each drug. Duration of prophylaxis depends on the surgical and the individual patients' risk. Extended prophylaxis in THR for up to 42 days with LMWH and up to 35 days with fondaparinux in hip fracture surgery is recommended. However extended prophylaxis after 14 days in TKR has not demonstrated a higher efficacy and should only be considered for patients with additional risk factors. In patients with isolated lower extremity injury or undergoing knee arthroscopy, LMWH should not be routinely used according to a low or a moderate risk and/or the duration of prophylaxis required. But LMWH has to be considered for patients with additional risk factors. Prophylaxis in other orthopedic procedures has not been assessed and will be extrapolated from the above recommendations.

Deep venous thrombosis after knee arthroscopy: a meta-analysis

PURPOSE

To better establish the incidence of deep venous thrombosis (DVT) after knee arthroscopy without prophylaxis.

TYPE OF STUDY

Meta-analysis.

METHODS

A MEDLINE search was performed to find published English-language studies of DVT following knee arthroscopy. Strict inclusion criteria required any investigation included for analysis to (1) be prospective, (2) include a population not given any antithrombotic prophylaxis, (3) perform universal screening of the lower extremity venous system using either ultrasound or venography, and (4) include a discrete population limited to unilateral arthroscopic knee surgery, exclusive of ligament surgery or open procedures. The results of the venographic studies were given additional weight mathematically to account for the increased sensitivity of this imaging modality compared with ultrasound in detecting DVT in asymptomatic lower extremities.

RESULTS

The unprophylaxed patient populations in the 6 studies that met inclusion criteria ranged from 64 to 184 patients, and totaled 684. The total incidence rate of DVT in each study ranged from 3.1% to 17.9%, whereas the incidence rate of proximal DVT ranged from none detected to 4.9%. The total DVT rate was not related to the method of DVT detection, whereas proximal DVT was only noted in the 2 studies using contrast venography. Combining the 6 studies yields a total DVT incidence of 9.9% (95% confidence interval, 8.1%-11.7%), and a proximal DVT incidence of 2.1% (95% confidence interval, 1.2%-3.0%).

CONCLUSIONS

DVT following knee arthroscopy is a consistent finding in studies of unprophylaxed patients when routine screening using ultrasound or contrast venography is used. Current data suggest an overall DVT rate of 9.9% and a proximal DVT rate of 2.1% after knee arthroscopy without antithrombosis prophylaxis.

LEVEL OF EVIDENCE

Level II, Systematic Review of Levels I and II Diagnostic Studies.

Deep venous thrombosis and pulmonary embolism after knee arthroscopy in athletes carrying the thrombophilic factor lupus anticoagulant

In patients undergoing arthroscopic knee surgery, deep venous thrombosis and pulmonary embolism are rare and there is not clear indication as to the necessity of thromboprophylactic treatment in these patients. However, the role of coagulation disorders in thrombotic events following arthroscopy is unknown. We report 2 cases of massive deep venous thrombosis and pulmonary embolism after knee arthroscopy in athletes carrying the thrombophilic factor lupus anticoagulant, but with no personal or familial history of thrombotic diseases. A few days after the arthroscopic intervention, both patients presented with deep venous thrombosis and 1 developed a severe pulmonary embolism. Blood examination showed that both athletes were lupus anticoagulant-positive. This is the first description of an association between venous thromboembolism, knee arthroscopy, and a prothrombotic condition. This report suggests that screening for hypercoagulability might be useful in athletes undergoing even minimally invasive orthopaedic surgery and that in cases of venous thromboembolism after knee arthroscopy, a prothrombotic disorder should be suspected.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

[Stationary thromboprophylaxis in casualty surgery. Relevance of postoperative mobility and preexisting risk factors]

The presented thromboprophylactic concept includes weight bearing and ankle motion as well as breathing therapy and drug prophylaxis (antiphlogistics, analgesic drugs, heparin). Routinely performed ultrasound screening of the deep veins (legs and pelvis) before release showed a low DVT incidence of 2.5% in a prospective clinical observation of 841 inpatients. Obesity, venous insufficiency, and a history of previous thromboembolic events were associated with a significantly increased risk of thrombosis (relative risk 4.1, 4,9, and 5.8, respectively) The duration of immobilization also had a relevant influence indicating that early postoperative physiotherapy in traumatology and orthopedic surgery has a widely underestimated thromboprophylactic effect.

Thromboembolic events after arthroscopic knee surgery

We present a case of fatal pulmonary embolus after knee arthroscopy to raise awareness of the frequency of this complication and the need for consideration of thromboembolic prophylaxis before knee arthroscopy.

Evidence-based orthopaedics: a primer

Evidence-based medicine has evolved from the need of solving clinical problems. In contrast to the traditional paradigm of clinical practice, evidence-based medicine acknowledges that intuition, clinical experience, and pathophysiologic rationale are not sufficient for making the best clinical decisions. Although evidence-based medicine recognizes the importance of clinical experience, it includes the evaluation of evidence from clinical research and the integration of patients' values, preferences, and actions for best clinical decision-making. To optimize this process, evidence-based medicine advocates that a formal set of rules must accompany training and clinicians' common sense to interpret and apply evidence from clinical research results effectively. We describe the critical appraisal of studies related to prognosis and therapy or prevention building on an example relevant for the clinical orthopaedist. Based on the example, the authors describe how clinicians can apply measures of association and of intervention effects to their practice and patient care. The authors conclude with describing the appraisal of systematic reviews, their application to the development of practice guidelines, and the process of guideline development and recommendations.

Venous thrombosis after hallux valgus surgery

BACKGROUND

Although surgery for the treatment of hallux valgus is frequently performed, the exact rate of deep vein thrombosis following this procedure is unknown. We performed a single-center, prospective, phlebographically controlled study to quantify the rate of venous thrombosis following operative correction of hallux valgus.

METHODS

Consecutive patients undergoing chevron bunionectomy for correction of hallux valgus deformity were enrolled in the study. Patients with clinical or hematological risk factors for venous thrombosis were excluded. One hundred patients with a mean age of 48.9 years were operated on and did not receive medical prophylaxis against thrombosis. All patients were assessed with phlebography at a mean of twenty-nine days postoperatively.

RESULTS

Venous thrombosis was found in four patients (4%). The mean age of these patients (and standard deviation) was 61.7 +/- 6.1 years compared with a mean age of 48.4 +/- 13.9 years for the patients in whom thrombosis did not develop (p = 0.034).

CONCLUSIONS

Patients are at a low risk for venous thrombosis following surgical treatment of hallux valgus. The need for prophylaxis against thrombosis should be calculated individually for each patient according to his or her known level of risk. Routine medical prophylaxis against thrombosis might be justified for patients over the age of sixty years.