Epidemiology of venous thromboembolism in Asian patients undergoing major orthopedic surgery without thromboprophylaxis. The SMART study

Incidence and preventive treatment for deep vein thrombosis with our own preventive protocol in total hip and knee arthroplasty

The aim of the present study was to investigate the perioperative and postoperative incidence of deep vein thrombosis (DVT) and validate the effectiveness of our own preventive treatment protocol for venous thromboembolism (VTE) occurrence in lower extremity arthroplasty patients. The subjects were 1,054 patients (mean age: 74.3 years) who underwent total hip arthroplasty (THA) or total knee arthroplasty (TKA) at our institutions between April 2014 and March 2017. We examined the frequencies of pre- and post-operative DVT by lower extremity Doppler images, and the incidence rate at proximal or distal regions as well as that according to preoperative DVT status were evaluated. Preoperative DVT was detected in 6.5% (69 cases) of our cohort and those were located 1.4% (15 cases) at proximal and 5.1% (54 cases) at distal regions. A significantly higher rate of postoperative DVT development was observed in preoperative DVT+ THA patients (P = 0.0075), but not in TKA patients only with a higher tendency (P = 0.56). The overall incidence of DVT up to 2 weeks after surgeries was 27.3% (288 cases); however, the rate in proximal femur regions was suppressed to 2.8% (30 cases), and there was no symptomatic pulmonary thromboembolism (PTE) case. The results demonstrated the importance of regular Doppler examination for early detection of postoperative DVT occurrence and the following immediate treatment initiation. Our own VTE preventive treatment protocol could reduce the development of proximal DVT, and the periodic monitoring as well as prompt treatment might prevent the fatal PTE. osteoarthritis (OA), rheumatoid arthritis (RA).

Varicose veins as a risk factor for venous thromboembolism in arthroplasty patients: Meta-analysis

OBJECTIVE

A meta-analysis to determine if patients with varicose veins are at an increased risk of venous thromboembolism (VTE) when undergoing major lower limb arthroplasty.

METHODS

Medline, Embase, and Cochrane Library databases were searched using appropriate terms for studies that reported post-operative VTE in patients who had lower limb arthroplasty with any history of varicose veins. Methodological quality of included studies was quantified using the Risk of Bias (ROB) assessment tools. Findings were reported using the meta-analysis of observational studies in epidemiology (MOOSE) checklist.

RESULTS

A total of 129 studies were identified with 11 observational studies being eligible for inclusion. This consisted of 265,194 patients who underwent lower limb arthroplasty, 2188 of which had pre-existing varicose veins. Overall, VTE occurred in 1845 patients, and 122 cases had varicose veins present at time of arthroplasty. Meta-analysis indicates that patients undergoing lower limb arthroplasty with varicose veins are at increased risk of having a VTE, OR 2.37, 95% CI 1.54-3.63, (p < 0.001). One study evaluated if previous varicose veins surgery influenced the risk of VTE in arthroplasty patients, OR 0.96 (95% CI 0.7-1.28), p = 0.429.

CONCLUSIONS

Varicose veins and lower limb arthroplasty are known independent risk factors for VTE. There is a paucity of data regarding the risk of VTE in patients undergoing lower limb arthroplasty who have co-existing varicose veins. This meta-analysis shows that patients with varicose veins are at an increased risk of VTE when undergoing major lower limb arthroplasty. Further studies are required in order to determine if such patients should undergo varicose vein surgery before undertaking major lower limb joint replacement.

Ethnicity-based differences in thrombosis in lower extremity vascular bypass: a review of current literature

INTRODUCTION

Understanding prothrombotic factors is important in vascular surgery for surgical planning, preoperative evaluation, and post-operative management. The purpose of this study was to investigate ethnicity-based differences in coagulation between East Asian and Western cohorts by comparing patency rates after infrainguinal bypass surgery.

EVIDENCE ACQUISITION

A review of infrainguinal bypass patients was conducted for East Asian (including Chinese, Japanese, and Korean) and Western (North American and European) studies between 1990 and 2015 within the Journal of Vascular Surgery. The number of patent grafts at 1-year and 5-years were calculated from reported patency rates for PTFE grafts, Dacron grafts, all prosthetic grafts, autogenous grafts, and all grafts. Statistical analysis was performed using Chi-square test for each graft type at each time point.

EVIDENCE SYNTHESIS

A total of 9972 grafts from 50 studies were included in our review. There were 3592 grafts from East Asian patients and 6380 grafts from Western patients. There was a statistically significant (P<0.05) difference between East Asian and Western cohorts in both 1-year and 5-year patency rates for PTFE, all prosthetic, and all grafts.

CONCLUSIONS

East Asians had significantly higher patency rates after infrainguinal bypass surgery for PTFE, all prosthetic, and all graft types compared with Westerners, showing an ethnicity-based difference in thrombosis. Further research is needed to identify the specific genetic or dietary influences causing this significant difference.

What is the best prophylaxis against venous thromboembolism in Asians following total knee arthroplasty? A systematic review and network meta-analysis

Purpose

Asians have a low venous thromboembolism (VTE) incidence following total knee arthroplasty (TKA). This systematic review and network meta-analysis was conducted to evaluate the best prophylaxis against VTE in Asians following total knee arthroplasty in current literature.

Materials and Methods

A systematic search of PubMed, Embase and CINAHL was conducted in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Prophylaxis types were separated into low-molecular-weight heparin (LMWH), novel oral anti-coagulants (NOAC), mechanical-only prophylaxis (MOP) and no prophylaxis (NP). The primary outcome was VTE incidence, grouped according to diagnosis modality (ultrasound, venography, clinical). The secondary outcome was bleeding incidence, grouped into minor and major bleeding.

Results

Fourteen eligible articles, totalling 4259 patients, were pooled with the following significant results: NOACs had lower venography-diagnosed VTE incidence than LMWH (12.77%, p = 0.02) and NP (20.64, p < 0.001). MOP had lower venography-diagnosed VTE incidence than LMWH (23.72%, p < 0.001), NOACs (10.95%, p < 0.001) and NP (31.59%, p < 0.001) but, interestingly, a statistically higher ultrasound-diagnosed VTE incidence than LMWH (6.56%, p = 0.024) and NP (4.88%, p = 0.026). No significant differences were observed between prophylaxis types for symptomatic VTE, pulmonary embolism (PE) or death. LMWH and NOACs had a higher minor bleeding incidence than NP (11.71%, p < 0.001 and 6.33%, p < 0.02, respectively). No significant differences were observed between prophylaxis types for major bleeding incidence.

Conclusion

NOACs are a superior form of chemoprophylaxis, compared with LMWH, in reducing venography-diagnosed VTE incidence with no added bleeding incidence. However, routine chemoprophylaxis may not be required as LMWH and NOACs do not appear to reduce symptomatic VTE incidence compared with MOP and NP with an increased minor bleeding incidence. Mechanical prophylaxis in the form of graduated compression stockings or intermittent pneumatic compression should be routinely considered with significantly lower rates of venography-diagnosed VTE compared with NP. On the basis of current evidence, we recommend an individualised approach to select the most appropriate prophylaxis type.

Thrombin antithrombin complex concentration as an early predictor of deep vein thrombosis after total hip arthroplasty and total knee arthroplasty

Aim

Early predictive markers of venous thromboembolism (VTE) after total hip arthroplasty (THA)/total knee arthroplasty (TKA) remain unclear. Our study identified early predictive markers for VTE after THA/TKA.

Methods

A single-institution retrospective review study was conducted between May 2020 and April 2022 (n = 256). All patients underwent Doppler ultrasounds exam in preoperation and seventh day after surgery. Deep vein thrombosis (DVT) was defined by Doppler ultrasound of the lower extremities, which revealed thrombosis. Thrombin-antithrombin complex (TAT), thrombomodulin (TM), and plasmin-antiplasmin complex (PIC) concentration were tested from each patient’s preoperative and postoperative days 1, 4, 7, 14. These values were then accessed via receiver operating characteristic (ROC) curve analysis and further quantified the level of this risk by concentration.

Results

On postoperative day 1 (pod-1), all patients’ TAT and PIC concentrations were significantly higher than those preoperatively (p < 0.05). The levels of TAT and PIC in patients in the DVT group on pod-1 were significantly higher than those in the non-DVT group (p < 0.05). At pod-1, the TAT concentration for DVT patients was 49.47 ng/mL compared to 20.70 ng/mL for non-DVT patients, PIC was 3.72μg/mL compared to 1.65μg/mL. ROC curve analysis demonstrated that a TAT concentration of 24.3 ng/mL had a sensitivity of 87.9% and a specificity of 69.1%.

Conclusion

TAT levels on pod-1 may predict DVT early after THA/TKA, which makes it possible for early intervention to decrease the incidence of DVT.

Postoperative Thromboembolism According to the Type of Surgery: A Nationwide Study in the Republic of Korea

Postoperative thromboembolism (TE) is a serious, but preventable, complication in surgical patients. Orthopedic surgery, neurosurgery, and vascular surgery are considered high risk for TE, and current guidelines recommend TE prophylaxis. However, insufficient data exist regarding TE risk in other general surgeries. This study identified the actual incidence and relative risk of postoperative TE in the real world, according to surgery type. Twenty-six surgeries between 1 December 2017 and 31 August 2019 were selected from the Health Insurance Review and Assessment Service database and analyzed for postoperative TE events. Among all patients, 2.17% had a TE event within 6 months of surgery and 0.75% had a TE event owing to anticoagulant treatment. The incidence of total TE events was the highest in total knee replacement (12.77%), hip replacement (11.46%), and spine surgery (5.98%). The incidence of TE with anticoagulant treatment was the highest in total knee replacement (7.40%), hip replacement (7.20%), and coronary artery bypass graft (CABG) surgery (3.81%). Hip replacement, total knee replacement, CABG surgery, spine surgery, and cardiac surgery except CABG surgery, showed relatively higher risks for total claimed venous TE. The relative risk of venous TE with anticoagulant treatment was the highest for hysterectomy, partial hepatectomy, hip replacement, cardiac surgery except CABG surgery, and total knee replacement. The relative risk of arterial TE was the highest for cardiac surgery, total knee replacement, and hip replacement. In the real world, the incidence of postoperative TE events from total knee replacement and those from hip replacement remain high, and some surgeries could have a relatively higher risk of TE than other surgeries. For patients undergoing these surgeries, studies to reduce the incidence of postoperative TE in clinical practice should be conducted.

Deep vein thrombosis after major orthopedic surgery in Taiwan: A prospective cross-sectional study and literature review

BACKGROUND/PURPOSE

Postoperative venous thromboembolism is an important complication in Taiwan. We prospectively investigated the occurrence of deep vein thrombosis (DVT) after major orthopedic surgery without pharmacologic thromboprophylaxis in a cohort of 120 patients (46 males, 74 females, median age 71 years) at our institute.

METHODS

Color duplex compression ultrasonography (CUS) was used to detect DVT before and after the operation, while contrast venography was performed postoperatively for comparison and validation.

RESULTS

Total knee arthroplasty (TKA, 57 cases) and total hip arthroplasty (23 cases) were the most commonly performed operations. The rate of postoperative DVT was 7.5% (9/120), including five with proximal DVT and four with distal DVT. All were detected in the limbs on the operated side. Four of them were symptomatic DVT cases. Venography was performed in 19 patients and confirmed most findings of CUS, indicating the effectiveness of CUS for detecting DVT. The type of surgery (TKA) was significantly correlated with postoperative DVT. No clinically symptomatic pulmonary embolism or sudden death events were noted.

CONCLUSION

Nine out of 120 (7.5%) orthopedic patients without pharmacologic thromboprophylaxis developed postoperative sonographic DVT in our study. The DVT rate is consistent with other reports from various Asian countries and evidence from meta-analyses.

Should all patients receive the same prophylaxis? Racial variation in the risk of venous thromboembolism after major abdominal operations

BACKGROUND

Whether prevention strategy for postoperative venous thromboembolism (VTE) should be tailored across racial groups remains unknown.

METHODS

Patients who underwent major abdominal operation in the Nationwide Inpatient Sample (NIS) were examined. Our primary outcome was postoperative VTE, and the secondary outcome was postoperative bleeding. Multivariable logistic regression analyses were performed and validated with the National Surgical Quality Improvement Program (NSQIP) database.

RESULTS

781,888 patients from NIS were analyzed. Overall VTE rate was 2.0%. Compared to White patients, Hispanic (OR 0.85, 95% CI 0.78-0.93, p < 0.01) and Asian patients (OR 0.49, 95% CI 0.40-0.61, p < 0.01) had significantly lower risks for VTE. In contrast, Asian patients had a significantly higher risk of bleeding (OR 1.39, 95% CI 1.24-1.56, p < 0.01). Similar trends were observed in NSQIP.

CONCLUSIONS

The risk-benefit ratio of postoperative VTE prophylaxis for Asian patients is roughly three times higher than that for White patients, suggesting a tailored approach is necessary.

Clinical Practice Guideline for Postoperative Rehabilitation in Older Patients With Hip Fractures

OBJECTIVE

The incidence of hip fractures is increasing worldwide with the aging population, causing a challenge to healthcare systems due to the associated morbidities and high risk of mortality. After hip fractures in frail geriatric patients, existing comorbidities worsen and new complications are prone to occur. Comprehensive rehabilitation is essential for promoting physical function recovery and minimizing complications, which can be achieved through a multidisciplinary approach. Recommendations are required to assist healthcare providers in making decisions on rehabilitation post-surgery. Clinical practice guidelines regarding rehabilitation (physical and occupational therapies) and management of comorbidities/complications in the postoperative phase of hip fractures have not been developed. This guideline aimed to provide evidence-based recommendations for various treatment items required for proper recovery after hip fracture surgeries.

METHODS

Reflecting the complex perspectives associated with rehabilitation post-hip surgeries, 15 key questions (KQs) reflecting the complex perspectives associated with post-hip surgery rehabilitation were categorized into four areas: multidisciplinary, rehabilitation, community-care, and comorbidities/complications. Relevant literature from four databases (PubMed, EMBASE, Cochrane Library, and KoreaMed) was searched for articles published up to February 2020. The evidence level and recommended grade were determined according to the grade of recommendation assessment, development, and evaluation method.

RESULTS

A multidisciplinary approach, progressive resistance exercises, and balance training are strongly recommended. Early ambulation, weigh-bearing exercises, activities of daily living training, community-level rehabilitation, management of comorbidities/complication prevention, and nutritional support were also suggested. This multidisciplinary approach reduced the total healthcare cost.

CONCLUSION

This guideline presents comprehensive recommendations for the rehabilitation of adult patients after hip fracture surgery.

Safety and Effectiveness of Apixaban in Japanese Patients With Venous Thromboembolism in Clinical Practice - A Post-Marketing Surveillance

BACKGROUND

A post-marketing surveillance study (STANDARD-VTE) evaluated the real-world safety and effectiveness of apixaban in Japanese patients prescribed for either the treatment of venous thromboembolism (VTE) or prevention of recurrent VTE.Methods and Results:Patients newly initiated on apixaban were followed up for 52 weeks or 28 days post-discontinuation. Subgroup analysis was performed on patients with and without active cancer, and on patients with provoked VTE and with unprovoked VTE. A total of 1,119 patients were enrolled. Of these, 43.1% were aged ≥75 years, 46.4% had body weight ≤60 kg, and 21.3% had active cancer; mean serum creatinine was 0.76 mg/dL. The incidence of adverse drug reactions (ADRs) was 8.85%, and that of severe ADRs was 3.22%. Incidence of any bleeding, major bleeding, and recurrent VTE was 6.70%, 3.40%, and 0.80%, respectively. In patients starting apixaban 10 mg twice daily, THE incidence of any bleeding and major bleeding was 7.72% and 3.86%, respectively. In patients with active cancer, THE incidence of any bleeding and major bleeding was 16.81% and 9.24%, respectively.

CONCLUSIONS

No new safety signals of apixaban were identified in Japanese patients with VTE. In this study, the safety and effectiveness of apixaban in real-world practice was consistent with the results of the apixaban phase III trial.

Are venous thromboembolism risk assessment tools reliable in the stratification of microvascular risk following lower extremity reconstruction?

Introduction

The incidence of flap failure is significantly higher in the lower extremity compared to free tissue transfer in the head, neck and breast. The most common cause of flap failure is venous thrombosis. The aim of this study was to assess the reliability of venous thromboembolism (VTE) risk assessment tools in this high-risk cohort and to assess the ability of such tools to identify patients at risk of developing microvascular venous thrombosis and venous thromboembolism following lower extremity free flap reconstruction.

Methods

A single centre retrospective cohort study was conducted between August 2012-August 2019. Adult patients who had undergone free tissue transfer following open lower extremity fractures were eligible for inclusion. All patients were retrospectively risk assessed using the Department of Health (DoH), Modified Caprini and Padua VTE risk assessment tools.

Results

Fifty-eight patients were included; all were at high risk of DVT according to the DoH (mean score ± SD, 3.7 ± 0.93), Caprini (10.2 ± 1.64) and Padua (5.4 ± 0.86) risk assessment tools. All patients received appropriate thromboprophylaxis; the incidence of symptomatic hospital acquired VTE was 3.5%. Micro-anastomotic venous thrombosis occurred in 4 patients resulting in one amputation. Partial flap necrosis occurred in 7 patients. There were no significant differences in scaled Caprini (median score, 10 vs 9, z = 1.289, p = 0.09), DoH (3 vs 3, z = 0.344, p = 0.36), and Padua (5 vs 5.5, z= -0.944, p = 0.17) scores between those with and without microvascular venous thrombosis.

Conclusion

This data suggests that current VTE risk assessment tools do not predict risk of microvascular venous thrombosis following lower extremity reconstruction. Further prospective studies are required to optimise risk prediction models and thromboprophylaxis use in this cohort.

Associations between Hip Fracture Operation Waiting Time and Complications in Asian Geriatric Patients: A Taiwan Medical Center Study

Early surgical intervention in hip fractures is associated with lower complications. This study aimed to determine the appropriate operation time among Asian geriatric patients. The data of 1118 elderly patients with hip fracture at Mackay Memorial Hospital from 1 January 2011, to 31 July 2019, were retrospectively examined. Association between operation waiting time and the occurrence of complications was calculated using a cubic spline model. Significantly increased incidence of pneumonia, myocardial infarction, and heart failure was observed in 30 and 90 days when the patient’s surgical waiting time exceeded 36 h. The incidence rates of pneumonia across the early and delayed groups within 30 and 90 days were 4.4% vs. 7.9%, and 6.2% vs. 10.7%, those of myocardial infarction were 3.0% vs. 7.2%, and 5.7% vs. 9.3%, and those of heart failure were 15.2% vs. 26.8%, and 16.2% vs. 28.5%. Deep vein thrombosis and pulmonary embolism were not associated with surgical delay. The overall 30-day mortality rate was 5.4%, and no significant difference was observed when the surgical waiting time exceeded 36 h. In summary, operation waiting time exceeding 36-h was associated with increased rates of pneumonia, myocardial infarction, and heart failure in Asian geriatric patients undergoing hip fracture surgery.

Clinical profile and management of patients with acute pulmonary thromboembolism - a single centre, large observational study from India

Acute pulmonary thromboembolism is associated with high mortality, similar to that of myocardial infarction and stroke. We studied the clinical presentation and management of pulmonary thromboembolism in the Indian population. An analysis of 140 patients who presented with acute pulmonary thromboembolism at a large volume center in India from June 2015 through December 2018 was performed. The mean age of our study population was 50 years with 59% being male. Comorbidities including deep vein thrombosis, diabetes mellitus, hypertension, and chronic obstructive pulmonary disease were present in 52.9%, 40%, 35.7% and 7.14% of patients, respectively. Out of 140 patients, 40 (28.6%) patients had massive pulmonary thromboembolism, 36 (25.7%) sub-massive pulmonary thromboembolism, and 64 (45.7%) had low-risk pulmonary thromboembolism. Overall, in-hospital mortality was 25.7%. Multivariate regression analysis found chronic kidney disease and pulmonary thromboembolism severity to be the only independent risk factors. Thrombolysis was performed in 62.5% of patients with a massive pulmonary thromboembolism and 63.9% of patients with a sub-massive pulmonary thromboembolism. In the massive pulmonary thromboembolism group, patients receiving thrombolytic therapy had lower mortality compared with patients who did not receive therapy (p=0.022), whereas this difference was not observed in patients in the sub-massive pulmonary thromboembolism group. We conclude that patients with acute pulmonary thromboembolism in India presented more than a decade earlier than our western counterparts, and it was associated with poor clinical outcomes. Thrombolysis was associated with significantly reduced in-hospital mortality in patients with massive pulmonary thromboembolism.

Symptomatic Venous Thromboembolism in Patients with Malignant Bone and Soft Tissue Tumors: A Prospective Multicenter Cohort Study

BACKGROUND

A prospective cohort study was conducted to determine the incidence and risk factors of symptomatic venous thromboembolism (sVTE) during the perioperative period in patients with malignant bone and soft tissue tumors.

METHODS

Patients with newly diagnosed primary malignant bone and soft tissue tumors for whom definitive surgery was planned were consecutively registered among 27 tertiary hospitals specializing in musculoskeletal oncology. Clinicopathological information on each patient was collected prospectively, and careful follow-up was conducted for 6 months after surgery. The study endpoint was the occurrence of sVTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

Eleven of 929 patients developed sVTE, including 8 patients with DVT, 2 with PE, and 1 with both, making the incidence of sVTE 1.18%. The median time until the development of sVTE after tumor resection was 11 days, ranging from - 7 to 95 days. Multiple logistic regression analyses revealed that ischemic heart disease as a comorbidity, maximum tumor diameter exceeding 8 cm, and elevated preoperative platelet count were independent risk factors for sVTE.

CONCLUSIONS

The incidence of sVTE in this series of patients with bone and soft tissue sarcomas was 1.18%, which was relatively lower than in previous retrospective studies. We identified the risk factors for sVTE specific to patients with malignant bone and soft tissue tumors, and these included ischemic heart disease, tumor size, and elevation of the preoperative platelet count.

The Effect of Type of Femoral Component Fixation on Mortality and Morbidity after Hip Hemiarthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Hip hemiarthroplasty is a well-established treatment of displaced femoral neck fracture, although debate exists over whether cemented or uncemented fixation is superior. Uncemented prostheses have typically been used in younger, healthier patients and cemented prostheses in older patients with less-stable bone. Also, earlier research has suggested that bone cement has cytotoxic effects and may trigger cardiovascular and respiratory adverse events.

QUESTIONS/PURPOSES

The aim of this systematic review and meta-analysis was to compare morbidity and mortality rates after cemented and uncemented hemiarthroplasty for the treatment of displaced femoral neck fractures in elderly patients.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched seven medical databases for randomized clinical trials and observational studies. We compared cemented and uncemented hemiarthroplasty using the Harris Hip Score (HHS), as well as measures of postoperative pain, mortality, and complications. Data were extracted and pooled as risk ratios or standardized mean difference with their corresponding 95% confidence intervals in a meta-analysis model.

RESULTS

The meta-analysis included 34 studies (12 randomized trials and 22 observational studies), with a total of 42,411 patients. In the pooled estimate, cemented hemiarthroplasty was associated with less risk of postoperative pain than uncemented hemiarthroplasty. There were no significant differences between groups regarding HHS or rates of postoperative mortality, pulmonary embolism, cardiac arrest, myocardial infarction, acute cardiac arrhythmia, or deep venous thrombosis.

CONCLUSIONS

While we found that cemented hemiarthroplasty results in less postoperative pain than uncemented hemiarthroplasty in older patients with femoral neck fracture, the lack of significant differences in functional hip scores, mortality, and complications was surprising. Further high-level research is needed.

Incidence of deep vein thrombosis and pulmonary embolism in Asian patients after direct anterior total hip arthroplasty

Objective

Venous thromboembolism (VTE), comprising either deep vein thrombosis (DVT) and pulmonary embolism (PE), is one of the most significant complications after Total Hip Arthroplasty (THA). The incidence of VTE after Direct Anterior Approach (DAA) hip arthroplasty is not known. Preceding studies have shown that internal femoral rotation used in the posterior approach leads to "scissoring" of the femoral vein and complete occlusion of flow. In contrast, external femoral rotation, utilized in an anterior approach, does not lead to any limitation in venous flow. We hypothesize that the rate of VTE post-operatively after DAA THA is comparable, if not lower, to other conventional approaches.

Methods

Retrospective analysis of medical records was examined to identify the incidence of symptomatic DVT within 6 months post-surgery, yielding 196 cases of elective primary DAA after THAs between 2015 and 2019. Aspirin was administered post-operatively. Corresponding imaging was performed for cases with high clinical suspicion of either DVT or PE based on Well's criteria.

Results

There were no cases of symptomatic DVT or fatal PE within 1 year of THA. There was 1 case of non-fatal subsegmental pulmonary embolism, treated with warfarin, which made an uneventful recovery. The overall incidence of symptomatic DVT and PE after DAA THA was 0% and 0.5% respectively in our study population.

Conclusion

Cumulative rate of symptomatic DVT and PE was less than 1%, demonstrating that incidence of VTE after DAA THA is low. DAA is a viable approach in Asian patients undergoing THA, in view of lower incidence of post-operative VTE compared values cited in other conventional surgical approaches. Further large scale studies involving use of routine post-operative venography for assessment will further validate our results.

Is the Oral Chemical Prophylaxis Necessary for the Prevention of Venous Thromboembolism after Joint Arthroplasty in a Korean Population?

Purpose

Venous thromboembolism (VTE) is a serious complication that may occur after a major orthopedic surgery. The aim of the present study was to determine the necessity of a chemical thromboprophylactic agent (rivaroxaban [RXB]) by analyzing the prevalence of VTE in Korean arthroplasty patients who received RXB for prophylaxis compared with those who did not receive RXB.

Materials and Methods

A total of 2,603 patients who underwent knee or hip arthroplasty between 1996 and 2017 were prospectively evaluated. Of these, 1,608 patients underwent surgery before January 2010 and were not administered any type of prophylaxis after surgery; the remaining 995 underwent surgery after 2010 and received oral RXB once daily for 5–13 days from the day after hemovac drain removal to postoperative day 14.

Results

The primary study outcome was the prevalence of VTE, pulmonary embolism or death during follow up. The overall incidence of VTE was 1.69% (n=44); of these, 12 occurred in the RXB group and 32 in the non-prophylactic group. The odds ratio of VTE in the RXB group was 0.61. However, the statistical power of the study was 0.313 due to the low incidence of VTE.

Conclusion

Treatment with oral chemical prophylaxis decreased the incidence of VTE after knee or hip arthroplasty in a Korean population. Furthermore, no serious complications occurred after administering oral RXB, which, coupled with its convenience, suggests oral RXB offers an attractive alternative to other agents. However, we recommend that further studies, including a multicenter study, be conducted to achieve adequate statistical power.

Determination of Risk Factors for Venous Thromboembolism by an Adapted Caprini Scoring System in Surgical Patients

Venous thromboembolism (VTE) is a frequent preventable complication among surgical patients. Precise risk assessment is a necessary step for providing appropriate thromboprophylaxis and reducing mortality as well as morbidity caused by VTE. We carried out this work to define the rate of VTE postoperatively, following a Caprini score, and to determine VTE risk factors through a modified Caprini risk scoring system. This multicenter, observational, cohort study involved 2,790,027 patients who underwent surgery in four Vietnamese hospitals from 01/2017 to 12/2018. All patients who were evaluated before surgery by using a Caprini risk assessment model (RAM) and monitored within 90 days after surgery. The endpoint of the study was ultrasound-confirmed VTE. Our data showed that the 90-day postoperative VTE was found in 3068 patients. Most of VTE (46.97%) cases were found in the highest risk group (Caprini score > 5). A total of 37.19% were observed in the high risk group, while the rest (15.84%) were from low to moderate risk groups. The likelihood of occurring VTE was heightened 2.83 times for patients with a Caprini score of 3–4, 4.83 times for a Caprini score of 5–6, 8.84 times for a score of 7–8, and 11.42 times for a score of >8, comparing to ones with a score of 0 to 2 (all p values < 0.05). Thus, the frequency of postoperative VTE rises substantially, according to the advanced Caprini score. Further categorizing patients among the highest risk group need delivering more appropriate thromboprophylaxis.

The incidence of symptomatic in-hospital VTEs in Asian patients undergoing joint arthroplasty was low: a prospective, multicenter, 17,660-patient-enrolled cohort study

PURPOSE

The aim of this study was to determine the real incidence of symptomatic in-hospital venous thromboembolism (VTE) and identify risk factors for VTEs in Asian patients undergoing total hip (THA) and total knee arthroplasty (TKA).

METHODS

A total of 17,660 patients (20,078 hips and knees) undergoing THA and TKA at 78 hospitals were enrolled. The composite incidence of symptomatic in-hospital DVT and PE was identified as the primary effectiveness outcomes. The primary safety outcomes were the incidences of postoperative complications, especially for major or minor bleeding. Secondary analyses were assessed to identify the risk factors for postoperative VTE.

RESULTS

The overall rates of symptomatic in-hospital DVT in patients undergoing THA and TKA were 0.21% (19/9022) and 0.36% (31/8638), respectively. Symptomatic PE was confirmed in one TKA patient. Safety analysis showed that the incidence of bleeding during hospital stays in patients undergoing THA and TKA was 0.10% (18/17,660). Increased VTE risks were associated with old age, high BMI index, hypertension, cerebrovascular disease, history of venous thromboembolism and no medical prophylaxis usage.

CONCLUSIONS

The incidence of symptomatic VTEs in Asian regions was low compared with that reported in studies targeting Western populations. Approximately 1 in 500 patients undergoing THA and approximately 1 in 300 patients undergoing TKA developed symptomatic VTEs prior to hospital discharge. Old age, high BMI, history of venous thromboembolism, hypertension, cerebrovascular disease, and no medication prophylaxis were risk factors identified in this study.

LEVEL OF EVIDENCE

Prospective cohort study; Level 2.

Mechanical thromboprophylaxis would suffice after total knee arthroplasties in Asian patients?

PURPOSE

Our prospective study evaluated the incidence and location of deep vein thrombosis (DVT), the risk factors for PE and the natural history of DVT after TKA in patients who have received only mechanical compression device without having any chemical thromboprophylaxis or therapeutic treatment.

METHODS

We studied 408 consecutive patients (691 knees) who underwent primary TKA; 283 patients had one-stage bilateral TKAs and 125 had unilateral TKAs. Coagulation assays, the full blood count and blood typing tests, and serum chemical profiles were undertaken in all patients on three separate occasions. Molecular genetic testing was performed preoperatively to detect the genetic traits involving DVT. Bilateral simultaneous or unilateral venograms were carried out at 6 or 7 days after operation. Perfusion lung scanning was undertaken before and at 7 or 8 days after operation.

RESULTS

In the 691 venograms in 408 patients, only 4 knees (0.6%) were positive for fresh thrombi. In the 4 knees with DVT, thrombi were located in the calf veins. We observed factor V Leiden mutation, antithrombin-III level, and prothrombin promoter G20210A mutation were absent in all patients. We saw no relationship between DVT and coagulation or thrombophilic data. No pulmonary embolism (PE) occurred as shown by negative perfusion lung scan and absence of symptoms.

CONCLUSION

We concluded that the combinations of absent thrombophilic polymorphisms with low clinical prothrombotic risk factors led to low prevalence of DVT and virtually absent PE after TKA in the current series of patients, who had received mechanical compression device only without chemical thromboprophylaxis.

Association study of miR-146a, miR-149, miR-196a2, and miR-499 polymorphisms with venous thromboembolism in a Korean population

Despite much progress in microRNA (miRNA) research, information regarding the association between miRNAs and venous thromboembolism (VTE), especially in Asian patients, remains limited. This case-control study sought to determine the correlation between the presence of polymorphisms in the genes encoding the miRNAs miR-146a, miR-149, miR-196a2, miR-499, and VTE in Korean patients. We observed no statistically significant differences in the genotype frequency of miRNA polymorphisms between 300 control individuals and 203 VTE patients. However, we observed a significant association between three allelic combinations of miRNA polymorphisms and VTE risk. Overall, our findings suggest that specific miRNA polymorphisms are associated with the risk of VTE in a Korean population.

Symptomatic pulmonary embolism following hip fracture: A nationwide study

INTRODUCTION

This study evaluated the incidence of symptomatic pulmonary embolism (PE), subsequent mortality, risk factors, and the effects of pharmacological thromboprophylactic intervention following hip fracture surgery in Taiwan.

MATERIALS AND METHODS

A nationwide study was conducted from February 2004 to September 2013. Hip fracture patients were placed into two groups: without symptomatic PE (control group) and with symptomatic PE (PE group). We analyzed the incidence of and risk factors for symptomatic PE, post-operative mortality rate, and effects of pharmacological thromboprophylactic intervention.

RESULTS

We identified 165,748 hip fracture patients. The 3-month cumulative incidence of post-operative symptomatic PE was 0.24% (n = 392). The cumulative 1-, 3-, and 6-month mortality rates were significantly higher in the PE group (16.1%, 23.0%, and 28.6%, respectively) than in the controls (3.3%, 6.7%, and 10.2%, respectively). Increased risk of post-operative symptomatic PE was associated with prior history of PE (adjusted odds ratio [OR], 40.00; 95% CI, 24.75-64.67; P < 0.001), female sex (adjusted OR, 1.33; 95% CI, 1.07-1.65; P = 0.009), older age (>75 years) (adjusted OR, 1.51; 95% CI, 1.20-1.91; P < 0.001), and hemiarthroplasty (adjusted OR, 1.23; 95% CI, 1.01-1.51; P < 0.043). Pharmacological thromboprophylaxis significantly reduced the incidence of post-operative PE (adjusted hazard ratio, 4.54; 95% CI, 2.08-9.88; P < 0.001).

CONCLUSIONS

The incidence of symptomatic PE after hip fracture surgery was not low in Asian patients, and PE significantly decreased patient survival rates. Some groups were at higher risk for PE; in these instances, thromboprophylaxis, prompt diagnosis, and subsequent intervention are advised.

Venous thromboembolism after total knee and hip arthroplasty. A retrospective study

OBJECTIVES

To evaluate the incidence and risk factors of Venous thromboembolism (VTE) among total knee arthroplasty (TKA)  and total hip arthroplasty (THA) patients following surgery. Methods: We conducted a retrospective review of electronic medical records of consecutive patients between January 2010 and January 2015 who underwent TKA or THA at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia.  Results: The incidence of symptomatic VTE was 1.9% (17 events, 95% CI: 1.1-2.8) in 756 patients who underwent 889 surgeries. All VTE cases developed before hospital discharge. Twelve (1.4%) patients developed pulmonary embolism, and 5 (0.6%) patients developed deep vein thrombosis. The majority of patients (n=557, 62.7%) underwent surgery for single TKA, and 138 (15.5%) patients underwent bilateral arthroplasty. Based on univariate risk analysis, bilateral arthroplasty was the only potential predictor for VTE after surgery.  Conclusion: The rate of symptomatic VTE in a Saudi population following arthroplasty is low and comparable to the international data. However, efforts and more trials are needed to further improve in-hospital thromboprophylaxis measures.

The Prophylaxis of Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular condition, after myocardial infarction and stroke. Prophylactic measures in accordance with current guidelines can significantly reduce the risk of VTE and the associated morbidity and mortality. Until now, the German interdisciplinary, evidence- and consensus-based (S3) clinical practice guideline on VTE prophylaxis was based on a complete review of all pertinent literature available in MEDLINE up to January 2008. More recent publications and drug approvals have made a thorough revision necessary.

METHODS

A systematic search was carried out in the MEDLINE and Embase databases for publications that appeared from 1 January 2008 to 7 August 2013. Updates of 5 national and international reference guidelines and 2 new Health Technology Assessment (HTA) reports were considered as well. A structured consensus-finding process was carried out with delegates from 27 scientific medical societies and from the Union of Medical Specialist Associations.

RESULTS

46 randomized controlled trials (RCTs) were included for critical appraisal. New findings led to re-evaluation of the value of compression stockings in combination with pharmacological prophylaxis (open recommendation), and suggest equal value of non-vitamin K antagonist oral anticoagulants (NOACs) and low molecular weight heparins (LMWH) or fondaparinux in elective hip and knee replacement (strong recommendation). For patients undergoing hip fracture surgery, we recommend LMWH or fondaparinux.

CONCLUSION

Further research is needed to assess the value of NOACs for pharmacological prophylaxis in orthopedic/trauma patients undergoing surgical procedures other than the ones mentioned above, and into the benefit and harm of new devices available for mechanical prophylaxis. The stringent implementation of basic measures such as early mobilization, movement exercises, and patient instruction is a key point to prevent venous thrombo - embolism.

Incidence of venous thromboembolism in Korea from 2009 to 2013

The incidence of venous thromboembolism (VTE) is lower in Asian populations than in Western populations. The objective of the present study was to evaluate the annual age- and sex-adjusted incidence (ASR) of VTE from 2009 to 2013 in South Korea. In addition, annual change in the pattern of VTE treatment during the study period was estimated because a new direct oral anticoagulant (DOAC) had become available and was covered by health insurance in Korea beginning in January 2013. VTE cases from 2009 to 2013 were retrospectively identified based on both diagnostic and medication codes of anticoagulants used for initial treatment using the Korean Health Insurance Review and Assessment Service (HIRA) databases. The incidence of VTE increased yearly. It was significantly higher in the older population than in the younger population, and it was higher in females than in males. In 2009, ASRs of VTE, deep vein thrombosis, and pulmonary embolism were 21.3, 8.1, and 13.2 cases per 100,000 individuals, respectively in 2009. These increased to 29.2, 12.7, and 16.6 cases per 100,000, respectively, in 2013. Prescription rates of warfarin and low-molecular–weight heparin decreased with the introduction of a new anticoagulant in 2013. The proportion of subjects who underwent mechanical procedures decreased annually. The ASR of VTE in Korea continuously increased from 2009 to 2013, reflecting an increased awareness and detection of VTE as well as improved survival of patients with cancer and other morbidities. Following its introduction, DOAC rapidly replaced other anticoagulants for the treatment of VTE.

Venous thromboembolism in Asia – an unrecognised and under-treated problem?

Venous thromboembolism (VTE) has been perceived for a long time to be less common in Asian populations, particularly in the Far East, than in Western populations. Generally, thromboprophylaxis is not implemented as frequently as it should be in high-risk patients. However, recent prospective studies undertaken in Asian countries have demonstrated higher rates of VTE after major surgery and in medical wards, approaching those observed in Western populations. Risk factors for VTE are not different in Asian patients from those of Western patients with the exception of thrombophilic mutations. Deficiencies of the natural anticoagulants (protein S, protein C, and antithrombin) are the predominant thrombophilias in Asia whereas factor V Leiden and prothrombin G20210A gene mutation are not found or rarely reported. Further large well-designed clinical studies are needed to evaluate the magnitude of the risk of VTE and the appropriate use of thromboprophylaxis in different clinical situations.

Incidence of acute pulmonary embolism, related comorbidities and survival; analysis of a Swedish national cohort

Background

The aim of the study was to determine the incidence of acute pulmonary embolism (PE) in Sweden and any regional differences. To assess short- and long-term survival analysis after an episode of PE, before and after excluding patients with known malignancies, and to determine the most common comorbidities prior to the PE event.

Methods

All in-hospital patients, including children, diagnosed with acute PE in 2005 were retrieved from the Swedish National Patient Registry (NPR) and incidence rates were calculated. All registered comorbidities from 1998 until the index events were collected and survival up to 4 years after the event were calculated and compared to matched controls.

Results

There were 5793 patients of all ages diagnosed with acute PE in 2005 resulting in a national incidence of 0.6/1000/year. The mean age was 70 years and 52% were women. The most frequent comorbidities were cardiac-, vascular-, infectious- and gastrointestinal diseases, injuries and malignancies. The mortality rates were more than doubled in patients with recent PE compared to that in a matched control group (49.1% vs 21.9%), and the excess mortality remained after exclusion of deaths occurring within one year and after exclusion of patients with any malignancy prior to the event.

Conclusions

PE is associated with high age as well as with multiple comorbidities, and with an increased short- and long-term mortality. This study highlights the importance of a proper follow-up after an acute PE.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0587-1) contains supplementary material, which is available to authorized users.

Pharmacological thromboprophylaxis and its impact on venous thromboembolism following total knee and hip arthroplasty in Korea: A nationwide population-based study

BACKGROUND

Limited data is available regarding the pharmacological prophylaxis for venous thromboembolism (VTE) in Asian patients undergoing total knee arthroplasty or total hip arthroplasty (TKA/THA).

METHODS

We performed a population-based epidemiological study using the Health Insurance Review and Assessment Service database to estimate the rate of pharmacological thromboprophylaxis and its impact on VTE in Korean patients who underwent TKA/THA between 2009 and 2013.

RESULTS

We identified 306,912 cases (TKA, 261,260; THA, 45,652). The pharmacological thromboprophylaxis rate was 57.16% (TKA, 58.32%; THA, 50.51%), which increased from 42.81% in 2009 to 65.92% in 2013 (P = 0.0165). Both low-molecular-weight-heparin (22.42%) and rivaroxaban (22.71%) were the most common drugs for prophylaxis. The number of patients aged ≥ 60 years (87.31% vs. 81.01%, P < 0.0001), cases requiring general anesthesia (20.70% vs. 18.37%, P < 0.0001), and cases requiring long hospital stay (median, 13 days vs. 12 days, P < 0.0001) were significantly greater in the pharmacological prophylaxis group. The incidence of VTE within 3 months of surgery was 1.52% (TKA, 1.46%; THA, 1.87%). Patients with pharmacological prophylaxis had higher VTE rates (TKA, 1.69% vs. 1.14%; THA, 2.30% vs. 1.43%) than those without prophylaxis, with advanced age, use of general anesthesia, and a longer hospital stay increasing the risk of VTE. However, rivaroxaban significantly reduced the incidence of VTE following TKA (0.82% vs. 1.14%; odd ratio [OR], 0.72; 95% CI, 0.65-0.79). Moreover, ≥ 10 days of pharmacological thromboprophylaxis was significantly associated with lower incidence of VTE after TKA (1.33% vs. 1.52%; OR, 0.87; 95% CI, 0.81-0.94).

CONCLUSION

This represents the largest epidemiological study showing a gradual increase in the use of pharmacological prophylaxis in Korean patients undergoing TKA/THA. Although the incidence of VTE is still low without pharmacological prophylaxis, this study demonstrates that the incidence of VTE can be reduced further using appropriate pharmacological thromboprophylaxis strategies.

Reduced cardiac function and risk of venous thromboembolism in Asian countries

Patients with reduced cardiac function are thought to have a higher risk of venous thromboembolism (VTE). Additionally, they are vulnerable to complications of pulmonary embolism (PE) as well as right heart failure (HF), which in return is supposed to increase the rate of mortality. Studies focusing on VTE in heart failure patients were rare in Asian countries before the 21st century. Nowadays, more and more data are becoming available in this field in Asia. It is already known that heart failure can increase the risk of VTE, but so far a consensus on this issue has not been reached for many years, not only in Asian countries but all over the world. This condition may be due to the detailed pathological advancement in Virchow’s triad and some other theories. In clinical practice, VTE, especially PE is difficult to diagnose in patients with heart failure because of overlapping symptoms (e.g. cough and chest pain) and the elevation of laboratory markers (e.g. probrain natriuretic peptide (NT-proBNP) and D-dimer in both heart failure and VTE patients). Management of VTE in heart failure patients is also controversial because heart failure patients always have complications, such as renal failure and hepatic failure, which increase the risk of bleeding. In this study, we analyzed data from China, Japan, Korea, Singapore and India mainly to get a better understanding of the research progress in VTE in patients with heart failure. The aim of this review is to discuss the risk, incidence, advancement of diagnosis, management and prevention of VTE in patients with heart failure in Asian countries.

Intermittent Pneumatic Compression for the Prevention of Venous Thromboembolism after Total Hip Arthroplasty

BACKGROUND

Venous thromboembolism (VTE) is a relatively common and potentially life threatening complication after major hip surgery. There are two main types of prophylaxis: chemical and mechanical. Chemical prophylaxis is very effective but causes bleeding complications in surgical wounds and remote organs. On the other hand, mechanical methods are free of hemorrhagic complications but are less effective. We hypothesized that mechanical prophylaxis is effective enough for Asians in whom VTE occurs less frequently. This study evaluated the effect of intermittent pneumatic compression (IPC) in the prevention of VTE after major hip surgery.

METHODS

Incidences of symptomatic VTE after primary total hip arthroplasty with and without application of IPC were compared. A total of 379 patients were included in the final analysis. The IPC group included 233 patients (106 men and 127 women) with a mean age of 54 years. The control group included 146 patients (80 men and 66 women) with a mean age of 53 years. All patients took low-dose aspirin for 6 weeks after surgery. IPC was applied to both legs just after surgery and maintained all day until discharge. When a symptom or a sign suspicious of VTE, such as swelling or redness of the foot and ankle, Homans' sign, and dyspnea was detected, computed tomography (CT) angiogram or duplex ultrasonogram was performed.

RESULTS

Until 3 months after surgery, symptomatic VTE occurred in three patients in the IPC group and in 6 patients in the control group. The incidence of VTE was much lower in the IPC group (1.3%) than in the control group (4.1%), but the difference was not statistically significant. Complications associated with the application of IPC were not detected in any patient. Patients affected by VTE were older and hospitalized longer than the unaffected patients.

CONCLUSIONS

The results of this study suggest that IPC might be an effective and safe method for the prevention of postoperative VTE.

Pulmonary embolism in non-brain tumor patients after surgery-a retrospective study in China

BACKGROUND

The incidence rate of pulmonary emboli (PE) is high in tumor patients; however, the morbidity and mortality associated with the development of PE after tumor surgery are unknown. We studied the clinical profiles and outcomes of patients with PE after non-brain tumor surgery.

METHODS

We retrospectively screened 55,967 patients who underwent non-brain tumor surgery at the Peking University Cancer Hospital from January 2008 to June 2015. Among them, 76 patients who were diagnosed with PE were enrolled in our study. Factors impacting the overall survival at 90 days were analyzed. A Kaplan-Meier curve was plotted for time to death or until day 90. Cox proportional hazard modeling was performed for univariate- and multivariate-adjusted factor analyses.

RESULTS

The morbidity rate was approximately 135.8 per 100,000 non-brain tumor surgery patients (possibly underestimated). When treated, seven patients had major bleeding, and 14 patients had clinically relevant non-major bleeding, which represented 9.2 and 18.4% of all the patients, respectively. The 3-month overall mortality rate was 11.8% in our study. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score and platelet distribution width (PDW) were independent risk factors for the prognosis of PE after non-brain surgery (P values of 0.001 and 0.016, respectively).

CONCLUSIONS

Treatment of PE in non-brain tumor surgical patients remained a challenge due to the high bleeding rate. The APACHE II score and PDW were independent prognostic factors of survival in patients with PE after non-brain tumor surgery; however, the study power was limited.

Incidences of Deep Vein Thrombosis and Pulmonary Embolism after Total Knee Arthroplasty Using a Mechanical Compression Device with and without Low-Molecular-Weight Heparin

Purpose

To investigate the incidence of thromboembolic events and complications related to bleeding after total knee arthroplasty (TKA) with a mechanical compression device alone or in combination with low-molecular-weight heparin (LMWH).

Materials and Methods

A total of 489 TKA patients (776 knees) were retrospectively reviewed for the incidence of thromboembolic events and complications related to bleeding. While 233 patients (354 knees) were treated with a mechanical compressive device without LMWH, 256 patients (422 knees) were treated with the mechanical compressive device along with LMWH.

Results

The incidences of deep vein thrombosis (DVT) and pulmonary embolism (PE) were 15 of 375 knees (4.0%) and 5 of 375 knees (1.3%), respectively, in the group that used only a mechanical compressive device, and 14 of 401 knees (3.4%) and 5 of 401 knees (1.2%), respectively, in the group that used the mechanical compressive device with LMWH. There was no significant difference between the two groups (p=0.125 and p=0.146, respectively). The postoperative hemovac drainage amount was 635±57 mL in the group with a mechanical compressive device only and 813±84 mL in the group with the device and LMWH; therefore, the amount of drainage was significantly greater in the latter group (p=0.013).

Conclusions

Mechanical compression alone for prophylaxis against DVT and PE after TKA can be an attractive option in Korean patients.

Preventing Venous Thromboembolism with Use of Intermittent Pneumatic Compression after Total Hip Arthroplasty in Korean Patients

Intermittent Pneumatic Compression (IPC) device has been used to prevent venous thromboembolism (VTE). This study investigated the effectiveness of IPC device. We evaluated incidences of deep vein thrombosis (DVT) and pulmonary embolism (PE) in total hip arthroplasty (THA) patients after use of IPC device, and compared with historical incidences from our institution. We applied IPC device in 741 patients who underwent 870 elective primary THAs from January 2010 to December 2013, DVT was detected in 3 patients (0.3%) by sonography, and one (0.1%) of them was symptomatic. Symptomatic PE occurred in 1 patient (0.1%) and there were no cases of fatal PE. The incidence of symptomatic DVT was significantly lower than the historical control (P = 0.042). The IPC is a safe and effective prophylaxis of VTE after primary THA in Korea.

Management of Venous Thromboembolisms: Part I. The Consensus for Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the existing literature, knowledge about the epidemiology of DVT is primarily based on investigations among Caucasian populations. There has been little information available about the epidemiology of DVT in Taiwan, and it is generally believed that DVT is less common in Asian patients than in Caucasian patients. However, DVT is a multifactorial disease that represents the interaction between genetic and environmental factors, and the majority of patients with incident DVT have either inherited thrombophilia or acquired risk factors. Furthermore, DVT is often overlooked. Although symptomatic DVT commonly presents with lower extremity pain, swelling and tenderness, diagnosing DVT is a clinical challenge for physicians. Such a diagnosis of DVT requires a timely systematic assessment, including the use of the Wells score and a D-dimer test to exclude low-risk patients, and imaging modalities to confirm DVT. Compression ultrasound with high sensitivity and specificity is the front-line imaging modality in the diagnostic process for patients with suspected DVT in addition to conventional invasive contrast venography. Most patients require anticoagulation therapy, which typically consists of parenteral heparin bridged to a vitamin K antagonist, with variable duration. The development of non-vitamin K oral anticoagulants has revolutionized the landscape of venous thromboembolism treatment, with 4 agents available,including rivaroxaban, dabigatran, apixaban, and edoxaban. Presently, all 4 drugs have finished their large phase III clinical trial programs and come to the clinical uses in North America and Europe. It is encouraging to note that the published data to date regarding Asian patients indicates that such new therapies are safe and efficacious. Ultimately, our efforts to improve outcomes in patients with DVT rely on the awareness in the scientific and medical community regarding the importance of DVT.

KEY WORDS

Combination therapy; Hypertension; α1-blocker.

Incidence and risk factors for venous thromboembolism following surgical treatment of fractures below the hip: a meta-analysis

Venous thromboembolism (VTE) is a common complication after surgical treatment of fractures, which is associated with significant morbidity and mortality. Identifying the risk factors for VTE is important for preventive strategies to reduce the incidence of VTE. Therefore, we conducted a meta-analysis to evaluate the incidence of VTE and the risk factors influencing the development of VTE in patients who underwent surgery for fractures below the hip. PubMed, Embase, Web of Science, SinoMed (Chinese BioMedical Literature Service System, China) and CNKI (National Knowledge Infrastructure, China) databases were systematically searched to identify cohort or case-control studies that investigated the incidence and risk factors for VTE following surgical treatment of fractures below the hip. VTE risk ratios (RRs) were pooled by use of a fixed-effect model or a random-effect model, depending on the heterogeneity among the included studies. Heterogeneity between the studies was assessed by I² statistics. Twenty-three studies with a total of 191 294 patients who met the inclusion criteria were included in this meta-analysis. Our results demonstrated that age (≥60 years) (RR = 1·85, 95% confidence interval (CI): 1·34, 2·55; P = 0·000), previous VTE(RR = 5·25, 95% CI: 2·77, 9·96; P = 0·000), heart failure (RR = 1·74, 95% CI: 1·34, 2·27; P = 0·000), current smoking status (RR = 1·23, 95% CI: 1·07, 1·41; P = 0·004), hypertension (RR = 1·62, 95% CI: 1·27, 2·06; P = 0·000), hyperlipidaemia (RR = 2·16, 95% CI: 1·79, 2·62; P = 0·000), diabetes mellitus (RR = 1·46, 95% CI: 1·27, 1·68; P = 0·000), obesity (RR = 1·58, 95% CI: 1·35,·1·85; P = 0·000), multiple fractures (RR = 2·14, 95% CI: 1·00, 4·60; P = 0·050), varicose veins (RR = 3·07, 95% CI: 1·12, 8·47; P = 0·030), prolonged operation time (weighted mean differences (WMD) = 1·22, 95% CI: 0·63, 1·81; P = 0·000) and prolonged bed rest time (WMD = 3·12, 95% CI: 2·96, 3·29; P = 0·000) were associated with an increased risk of developing VTE. The other variables, including age (<60 years), previous smoking, immobility, pregnancy, cancer, open fractures and combination with trauma were not identified as significant risk factors for VTE. Almost all the risk factors mentioned above are in line with the known risk factors for VTE following surgery for fractures below the hip. Thus, surgeons should pay close attention to patients with these medical conditions in order to reduce the incidence of VTE following surgical treatment of fractures below the hip.

Venous Thromboembolism Following Hip and Knee Replacement Arthroplasty in Korea: A Nationwide Study Based on Claims Registry

The aim of this study was to examine the incidence and trends of clinically relevant venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) after hip and knee replacement arthroplasty (HKRA) in Korea. Between January 1 and December 31, 2010, 22,127 hip replacement arthroplasty (HRA) patients and 52,882 knee replacement arthroplasty (KRA) patients were enrolled in the analysis using the administrative claims database of the Health Insurance Review and Assessment Service (HIRA). All available parameters including procedure history and clinically relevant VTE during the 90 days after HKRA were identified based on diagnostic and electronic data interchange (EDI) codes. The overall incidence of VTE, DVT, and PE during the 90 days was 3.9% (n=853), 2.7% (n=597), and 1.5% (n=327) after HRA, while the incidence was 3.8% (n=1,990), 3.2% (n=1,699), and 0.7% (n=355) after KRA. The incidence of VTE after HKRA was significantly higher in patients who had previous VTE history (odds ratio [OR], 10.8 after HRA, OR, 8.5 after KRA), chronic heart failure (2.1, 1.3), arrhythmia (1.8, 1.7), and atrial fibrillation (3.4, 2.1) than in patients who did not. The VTE incidence in patients with chemoprophylaxis was higher than that in patients without chemoprophylaxis. The incidence of VTEs revealed in this retrospective review was not low compared with the results of the studies targeting other Asian or Caucasian populations. It may warrant routine prevention including employment of chemoprophylaxis. However, the limitation of the reviewed data mandates large scale prospective investigation to affirm this observation.

Heart failure and risk of venous thromboembolism: a systematic review and meta-analysis

BACKGROUND

Venous thromboembolism is a major global health problem that is often secondary to other clinical situations. Many studies have investigated the association between venous thromboembolism and heart failure, but have yielded inconsistent findings. We aimed to quantify the absolute and relative risks (RR) for venous thromboembolism in patients with heart failure after hospital admission. We also assessed rates of venous thromboembolism in patients in different settings.

METHODS

In this systematic review and meta-analysis, we searched for studies investigating the risk of venous thromboembolism in patients in hospital with heart failure. We searched for studies published between Jan 1, 1955, and March 31, 2015, in PubMed, Embase, Evidence-Based Medicine Reviews, Allied and Complementary Medicine Database, Ovid HealthSTAR, Global Health, Ovid Nursing Database, Web of Science, CINAHL Plus, ProQuest Central, Conference Papers Index, BIOSIS Previews, and ClinicalTrials.gov. All cohort studies and subgroup analyses of randomised controlled trials (RCTs) were eligible for inclusion if they reported venous thromboembolism rates (number of events per follow-up period) or RR estimates. We extracted data from published reports and contacted the corresponding authors of records with insufficient quantitative data. RRs and 95% CIs were pooled using a random-effects model. This study is registered with PROSPERO, number CRD42014015504.

FINDINGS

Of 8673 records identified, we included 71 studies with data from 88 cohorts in our analysis, with 59 cohorts included in the assessment of venous thromboembolism rates and 46 cohorts included in the meta-analysis of heart failure and risk of venous thromboembolism. Venous thromboembolism rates varied widely in patients in hospital with heart failure from different settings. The overall median symptomatic venous thromboembolism rate was 2·48% (IQR 0·84-5·61); rates was were 3·73% (1·05-7·31) for patients who did not receive thromboprophylaxis and 1·47% (0·64-3·54) for those who did. Overall, patients with heart failure in hospital had an RR of 1·51 (1·36-1·68) for venous thromboembolism. The overall I(2) statistic was 96·1% and there was no evidence of publication bias (Egger's test, p=0·46).

INTERPRETATION

Heart failure is a common independent risk factor for venous thromboembolism. Thromoboprophylaxis should be considered in clinical practice for high-risk patients.

FUNDING

National Natural Science Foundation.

Clinical Performance of the 1st American Academy of Orthopaedic Surgeons Clinical Guideline on Prevention of Symptomatic Pulmonary Embolism after Total Knee Arthroplasty in Korean Patients

We sought to document the clinical performance of the 1st American Academy of Orthopaedic Surgeons (AAOS) guideline on the prevention of symptomatic pulmonary embolism (PE) after total knee arthroplasty (TKA) in Korean patients, in terms of the proportions of the each risk-stratified group, efficacy and safety. Consecutive 328 patients underwent TKA were preoperatively assessed for the risks of PE and bleeding and categorized into 4 groups: 1) standard risk, 2) high risk for PE, 3) high risk for bleeding, and 4) high risks both for PE and bleeding. One of three options was administered according to the groups (aspirin in group 1 or 4; enoxaparin and following aspirin in group 2; antithrombotic stocking in group 3). Incidences of symptomatic deep vein thrombosis (DVT) and PE, and major or minor bleeding complications were evaluated. Majority of the patients (86%) were assessed to be with standard risks both for PE and bleeding. No patient experienced symptomatic DVT or PE and major bleeding. Eleven percent of the patients discontinued chemoprophylaxis because of bleeding-related wound complication. In conclusion, the 1st AAOS guideline functions successfully in Korean patients undergoing TKA in terms of prevention of symptomatic DVT and PE while avoiding major bleeding complications.

Incidence and Factors Predicting Venous Thromboembolism After Surgical Treatment of Fractures Below the Hip

OBJECTIVES

This study was designed to investigate the incidence and risk factors of postoperative venous thromboembolism (VTE) in a series of patients with fractures below the hip. In addition, we sought to examine the rates of VTE before and after introduction of thromboprophylaxis.

DESIGN

Retrospective review.

SETTING

University-based academic medical center.

PATIENTS

Nine hundred one consecutive patients met the inclusion criteria. Of the 901 patients, 337 (37.4%) were treated before the initiation of institutional guidelines for thromboprophylaxis and 564 (62.6%) received thromboprophylaxis in accordance with our hospitalization protocol.

INTERVENTION

Surgical intervention for fractures occurring in the lower extremity below the hip.

MAIN OUTCOME MEASUREMENTS

Symptomatic thromboembolic events within 90 days of surgery and risk factors of postoperative VTE.

RESULTS

Of the 901 patients, 25 (2.7%) had confirmed symptomatic deep vein thrombosis and 13 (1.4%) had symptomatic pulmonary embolism. The overall incidence of symptomatic VTE was significantly different between the patients not receiving thromboprophylaxis (6.8%; 23 of 337) and those receiving thromboprophylaxis (2.3%; 13 of 564). Of the 31 variables tested for an association with VTE, an advanced age of more than 60 years, cardiovascular disease, and chronic lung disease were independent risk factors.

CONCLUSIONS

Clinically detectable VTE in fractures of the lower extremity below the hip are not uncommon, and thromboprophylaxis seemed to decrease the incidence of postoperative VTE.

LEVEL OF EVIDENCE

Prognostic Level II. See the guidelines for authors for a complete description of levels of evidence.