Venous thromboembolism in pregnant Chinese women

Pregnancy-related venous thromboembolism in Wuhan, China 2010-2022: A case-control study

OBJECTIVE

To explore the time trends and risk factors for pregnancy-related venous thromboembolism (VTE) in the Chinese population.

METHODS

A case-control study was conducted with 120 652 pregnancies between Jan 2010 and June 2022 in Wuhan, China. Medical records from pregnant patients with VTE and patients without VTE were reviewed and analyzed.

RESULTS

There were 197 cases of VTE diagnosed during pregnancy or postpartum, with an overall incidence of 1.63 per 1000 pregnancies, and the incidence rate trend of VTE was increasing year by year and then declining. The incidence of deep venous thrombosis (DVT) was 1.24 per 1000 pregnancies (76.1%). Consistent with previous studies, most VTE occurred in the puerperium (1.05 per 1000 pregnancies, 64.5%). Significant risk factors included immobility, previous VTE, systemic infection, BMI over 30, and hypertensive disorders of pregnancy.

CONCLUSION

Pregnancy-related VTE is not uncommon in China which is consistent with current foreign reports, and the change in incidence trend may be related to greater physicians' understanding of VTE and effective preventive measures after the publication of Chinese guidelines.

Development of a risk assessment scale for perinatal venous thromboembolism in Chinese women using a Delphi-AHP approach

Background

The treatment and prevention of perinatal venous thromboembolism (VTE) are challenging because of the potential for both fetal and maternal complications.

Methods

This study developed a rapid assessment scale for VTE and evaluate its validity based on Delphi-AHP (Analytic Hierarchy Process) method in China. The research was conducted by literature retrieval and two rounds of Delphi expert consultation. The item pools of the scale were developed and a questionnaire was designed according to literature retrieval published between 2010 and 2020. A survey was conducted among experts from 25 level A hospitals in China, and data of experts’ opinions were collected and analyzed by the Delphi method.

Results

A perinatal VTE risk assessment scale was formed, including 5 first-level items, 20 s-level items and 40 third-level items. The response rates in the two rounds of expert consultation were 97.4% and 98.0%, and the authoritative coefficients were 0.89 and 0.92. The coefficients of variation ranged from 0.04 to 0.28.

Conclusions

The scale is significantly valid and reliable with a high authority and coordination degree, and it can be used to assess the risk of perinatal VTE and initiate appropriate thrombophylactic interventions in China.

Ethnoracial variations in venous thrombosis: Implications for management, and a call to action

Despite decades of improvement in its diagnosis and management, venous thromboembolism (VTE) remains a significant cause of cardiovascular morbidity and mortality. Clinically relevant differences exist in the risk of symptomatic VTE among ethnoracial groups. Underlying these differences in rates of VTE are patterns of known genetic thrombophilias, which may also influence the risks of major bleeding related to vitamin K antagonists or direct oral anticoagulants. In addition, social factors, differential access to care, and disease awareness differ between ethnoracial groups, which contributes to disparities in VTE outcomes that include higher fatal events. The vast majority of participants included in clinical trials for the prevention and treatment of VTE have been White Caucasian, which limits our understanding of the differential impact of these agents in non-White ethnoracial groups. Increasing the participation in clinical trials of diverse ethnoracial groups should be a priority, especially those groups who are disproportionately affected by the burden of VTE, or possible bleeding complications when exposed to anticoagulants. Advocacy by patients, researchers, and regulatory bodies is crucial to ensure adequate enrolment of diverse ethnoracial groups in order to best inform clinical decisions to optimize VTE prevention and treatment for non-White populations.

Epidemiology of pregnancy-associated pulmonary embolism in South Asian multi-ethnic country: Mortality trends over the last four decades

OBJECTIVE

To determine the cumulative incidence, time of occurrence and risk factors of pregnancy-associated pulmonary embolism (PE) in Singapore, and to review the maternal mortality ratio of PE over the last four decades.

STUDY DESIGN AND SETTING

In this retrospective epidemiology review, women with pregnancy-associated PE were identified via International Classification of Diseases codes and included if they had been objectively diagnosed on imaging with PE during pregnancy or within 6 weeks postpartum from 2004 to 2016 at KK Women's and Children's Hospital (KKH) and Singapore General Hospital (SGH) in Singapore. The medical records were reviewed and the time of occurrence of confirmed PE cases and risk factors for PE were noted.

RESULTS

There were 18 PE cases out of 174 708 deliveries, of which two were fatal, giving a cumulative incidence of PE at 1.03 per 10 000 deliveries and a mortality rate of 11.1%. The maternal mortality ratio is 1.14 per 100 000 deliveries, the lowest compared to that of the previous three decades (2.5-4.9 per 100 000 deliveries). Majority of PE (66.7%) occurred during the first 2 weeks postpartum. Cumulative incidence of postpartum PE was four times more in caesarean section compared to vaginal delivery at 1.58 per 10 000 deliveries and 0.40 per 10 000 deliveries, respectively.

CONCLUSION

Although the cumulative incidence of pregnancy-associated PE in Singapore is low, it is comparable to the United Kingdom (UK) and United States (US). Risk assessment and thromboprophylaxis have decreased PE mortality significantly during this period.

Risk of venous thromboembolism in Chinese pregnant women: Hong Kong venous thromboembolism study

Background

Previous Caucasian studies have described venous thromboembolism in pregnancy; however, little is known about its incidence during pregnancy and early postpartum period in the Chinese population. We investigated the risk of venous thromboembolism in a "real-world" cohort of pregnant Chinese women with no prior history of venous thromboembolism.

Methods

In this observational study, 15,325 pregnancies were identified in 14,162 Chinese women at Queen Mary Hospital, Hong Kong between January 2004 and September 2016. Demographic data, obstetric information, and laboratory and imaging data were retrieved and reviewed.

Results

The mean age at pregnancy was 32.4±5.3 years, and the median age was 33 years (interquartile range, 29-36 yr). Pre-existing or newly diagnosed diabetes mellitus was present in 627 women (4.1%); 359 (0.7%) women had pre-existing or newly detected hypertension. There was a small number of women with pre-existing heart disease and/or rheumatic conditions. Most deliveries (86.0%) were normal vaginal; the remaining were Cesarean section 2,146 (14.0%). The incidence of venous thromboembolism was 0.4 per 1,000 pregnancies, of which 83.3% were deep vein thrombosis and 16.7% were pulmonary embolism. In contrast to previous studies, 66.7% of venous thrombosis occurred in the first trimester.

Conclusion

Chinese women had a substantially lower risk of venous thromboembolism during pregnancy and the postpartum period compared to that of Caucasians. The occurrence of pregnancy-related venous thromboembolism was largely confined to the early pregnancy period, probably related to the adoption of thromboprophylaxis, a lower rate of Cesarean section, and early mobilization.

Establishment of a risk assessment tool for pregnancy-associated venous thromboembolism and its clinical application: protocol for a prospective observational study in Beijing

BACKGROUND

The risk of venous thromboembolism (VTE) during pregnancy and puerperal periods is significantly higher than during the non-pregnant period and is one of the major causes of maternal mortality. Developed countries have promulgated guidelines for risk assessment and prevention of maternal VTE, and standardized management has led to a significant reduction in maternal mortality. However, there is a paucity of relevant research related to pregnancy and puerperal VTE in China.

METHODS/DESIGN

We will perform a prospective cohort study and recruit 13,000 pregnant women from 2018 to 2020 in Beijing, China. VTE risk assessment will be conducted using the Royal College of Obstetricians and Gynaecologists (RCOG) pregnancy and puerperal VTE risk-assessment-scoring tool during early and late pregnancy, as well as during the puerperal period. Venous ultrasonography of lower extremities, routine blood tests, and coagulation parameters will be examined. These VTE risk assessments will be performed again if patients have VTE-related symptoms during their pregnancies, or if any of the following occur: (1) patients are hospitalized over 7 days due to any pregnancy complications; (2) patients are placed under strict bed rest for ≥ 3 days to prevent miscarriage. For patients with a confirmed diagnosis of VTE, treatment and follow-up plans will be decided jointly by the obstetricians, vascular surgeons, and pulmonologists. All patients in the study will be followed up by dedicated healthcare providers for up to 42 days postpartum. Statistical analyses will be performed to test the feasibility of the RCOG scoring tool for the Chinese population. The RCOG scoring tool will then be revised based upon the characteristics of the Chinese population, and the revised assessment scoring tool will then be tested in the cohort to evaluate its efficacy. Finally, a pregnancy and puerperal VTE risk-assessment tool will be proposed based on our study results.

DISCUSSION

This study will establish a preliminary VTE risk-assessment tool that is applicable to pregnant and puerperal women in China and provide guidelines for further thrombophylactic interventions. Furthermore, we wish to draw increased attention to pregnancy-associated VTE to reduce VTE-related mortality.

TRIAL REGISTRATION

Chi CTR1800015848 (04/24/2018).

The clinical significance of D-dimer concentrations in patients with gestational hypertensive disorders according to the severity

Objective

Pregnancy is a major risk factor of thromboembolism, and the patients with preeclampsia (PE) are known to have higher risk of thromboembolic complications than normal pregnant women. D-dimer is a well-established laboratory marker for the screening of venous thromboembolism (VTE), but the concentrations of d-dimer tend to increase physiologically in pregnant women throughout the gestational age. We performed this study to evaluate the clinical significance of d-dimer concentrations in patients with gestational hypertensive disorders (GHD) according to the severity.

Methods

Retrospective cohort study was performed in one institution. Singleton pregnant women with GHD were enrolled, and their antepartum concentrations of d-dimer were measured as a part of routine evaluation for patients suspected with PE. Patients with multiple gestations, rheumatic diseases, autoimmune diseases, or suspected VTE were excluded. A categorization of severity about PE was based on the general criteria.

Results

In 73.3% of study population, their d-dimer concentrations exceeded the normal range (>0.55 mg/L). A significantly greater proportion of pregnant women had excessive concentrations of d-dimer in the severe GHD than in the non-severe GHD (89.8% vs. 53.7%; P<0.01). Patients with severe GHD had significantly higher median concentrations of d-dimer than those with non-severe GHD (median [range], 2.00 mg/L [0.11 to 7.49] vs. 0.71 mg/L [0.09 to 5.39]; P<0.01) although their earlier gestational ages of sampling.

Conclusion

Maternal concentrations of d-dimer were significantly elevated in patients with severe features than those without severe features among those with GHD. Some pregnant women with GHD can have markedly elevated concentrations of d-dimer without any evidence of current VTE.

Elevated venous thromboembolism risk in preeclampsia: molecular mechanisms and clinical impact

Venous thromboembolism (VTE) remains a leading cause of maternal death and morbidity in the developed world. Strategies for prevention of VTE in pregnancy have been the subject of recent guidelines and consensus statements. These guidelines recommend thrombosis prevention in women who have risk factors associated with an elevated VTE risk. Preeclampsia is characterized by maternal hypertension and proteinuria developing after 20 weeks gestation, complicating up to 7% of pregnancies and is associated with a massive annual morbidity and mortality burden. Women with preeclampsia have been shown to be at increased risk of VTE with studies to date suggesting that this risk may be up to 5-fold greater than the risk of pregnancy-associated VTE in the general population. Despite the fact that preeclampsia is so common and potentially devastating, our understanding of its pathogenesis and potential therapeutic strategies remain poor. In addition, the mechanisms underlying the prothrombotic phenotype in preeclampsia are also poorly characterized although a number of potential mechanisms have been postulated. Derangements of platelet and endothelial activation and impairment of endogenous anti-coagulant pathways have been reported and may contribute to the observed VTE risk. Recently, evidence for the role of neutrophil extracellular traps (NETs) and cell-free DNA in the pathogenesis of VTE has emerged and some evidence exists to suggest that this may be of relevance in preeclampsia. Future studies aimed at understanding the diagnostic and potential therapeutic relevance of this procoagulant state are likely to be of enormous clinical benefit for pregnant women affected with this potentially devastating condition.

Thromboembolism in pregnancy: challenges and controversies in the prevention of pregnancy-associated venous thromboembolism and management of anticoagulation in women with mechanical prosthetic heart valves

Thromboembolism in pregnancy is an important clinical issue. Despite identification of maternal and pregnancy-specific risk factors for development of pregnancy-associated venous thromboembolism, limited data are available to inform on optimal approaches for prevention. The relatively low overall prevalence of pregnancy-associated venous thromboembolism has prompted debate about the validity of recommendations, which are mainly based on expert opinion, and have resulted in an increased use of pharmacological thromboprophylaxis in pregnancy and postpartum. A pragmatic approach is required in the absence of more robust data. Anticoagulation management of pregnant women with mechanical prosthetic heart valves is particularly challenging. Continuation of therapeutic anticoagulation during pregnancy is essential to prevent valve thrombosis. Warfarin, the most effective anticoagulant, is associated with adverse fetal outcomes, including embryopathy and stillbirth. Fetal outcome is improved with therapeutic-dose low-molecular-weight heparin, but there may be more thromboembolic complications. More intensive anticoagulation, targeting higher trough anti-Xa levels, may reduce the risk of valve thrombosis.

Cesarean section in the People's Republic of China: current perspectives

OBJECTIVE

To review the current knowledge on the prevalence, reasons, and consequences of cesarean sections in the People's Republic of China.

METHODS

Peer-reviewed articles were systematically searched on PubMed. The following Chinese databases were comprehensively searched: the China National Knowledge Infrastructure, Wanfang, and the VIP information. The databases were searched from inception to September 1, 2013. Two reviewers independently screened the titles and abstracts for eligibility. Full texts of eligible papers were reviewed, where relevant references were hand-searched and reviewed.

FINDINGS

Sixty articles were included from PubMed, 17 articles were intentionally picked out from Chinese journals, and five additional articles were added, for a total of 82 articles for the analysis. With a current national rate near 40%, the literature consistently reported a rapid rise of cesarean sections in the People's Republic of China in the past decades, irrespective of where people lived or their socioeconomic standing. Nonclinical factors were considered as the main drivers fueling the rise of cesareans in the People's Republic of China. There was a lively debate on whether women's preferences or providers' distorted financial incentives affected the rise in cesarean sections. However, recent evidence suggests that it might be the People's Republic of China's health development approach - focusing on specialized care and marginalizing primary care - that is playing a role. Although 30 articles were identified studying the consequences of cesareans, the methodologies are in general weak and the themes are out of focus.

CONCLUSION

The overuse of cesareans is rising alarmingly in the People's Republic of China and has become a real public health problem. No consensus has been made on the leverage factors that drive the cesarean epidemic, particularly for those nonclinical factors. The more macro level structural factors may have played a part, though further research is warranted to understand the mechanisms. Knowledge of the consequences of cesareans, particularly for women, is limited in the People's Republic of China, leaving a substantial literature gap.

The incidence of first venous thromboembolism in and around pregnancy using linked primary and secondary care data: a population based cohort study from England and comparative meta-analysis

Background

Recent linkage between primary and secondary care data has provided valuable information for studying heath outcomes that may initially present in different health care settings. The aim of this study was therefore, twofold: to use linked primary and secondary care data to determine an optimum definition for estimating the incidence of first VTE in and around pregnancy; and secondly to conduct a systematic literature review of studies on perinatal VTE incidence with the purpose of comparing our estimates.

Methods

We used primary care data from the Clinical Practice Research Datalink (CPRD), which incorporates linkages to secondary care contained within Hospital Episode Statistics (HES) between 1997 and 2010 to estimate the incidence rate of VTE in the antepartum and postpartum period. We systematically searched the literature on the incidence of VTE during antepartum and postpartum periods and performed a meta-analysis to provide comparison.

Findings

Using combined CPRD and HES data and a restrictive VTE definition, the absolute rate during the antepartum period and first six weeks postpartum (early postpartum) were 99 (95%CI 85–116) and 468 (95%CI 391–561) per 100,000 person-years respectively. These were comparable to the pooled estimates from our meta-analysis (using studies after 2005) during the antepartum period (118/100,000 person-years) and early postpartum (424/100,000 person-years). When we used only secondary care data to identify VTE events, incidence was lower during the early postpartum period (308/100,000 person-years), whereas relying only on primary care data lead to lower incidence during the time around delivery, but higher rates during the postpartum period (558/100,000 person-years).

Conclusion

Using combined CPRD and HES data gives estimates of the risk of VTE in and around pregnancy that are comparable to the existing literature. It also provides more accurate estimation of the date of VTE diagnosis which will allow risk stratification during specific pregnancy and postpartum periods.

Maternal obesity and venous thromboembolism

The incidence of obesity in pregnancy has increased rapidly in the last decade. Obesity is a risk factor for venous thromboembolism outside of pregnancy and previous studies of maternal death in the UK have identified obesity as a risk factor in pregnancy. As a result the Royal College of Obstetricians and Gynaecologists have targeted obesity as a risk factor in evaluation of the need for thromboprophylaxis in pregnancy. This article highlights the evidence that obesity increases the risk of venous thromboembolism in pregnancy and the puerperium, discusses thromboprophylaxis and appropriate dosing in obese parturients and details the anaesthetic implications of the 2009 Royal College of Obstetricians and Gynaecologists' guidelines. More clinical studies are required to clarify the appropriate dose of low-molecular-weight heparin in an obese parturient.

Thrombophilia among Chinese women with venous thromboembolism during pregnancy

AIMS

To assess the prevalence of thrombophilia among Chinese women with venous thromboembolism (VTE) developed during pregnancy.

METHODS

Based on information from a tertiary teaching unit, all recorded cases of deep vein thrombosis (DVT) and pulmonary embolism (PE) during pregnancy diagnosed between 1997 and 2005, were assessed for prevalence of thrombophilia. Fifty-five healthy women, who had at least one normal pregnancy but without any previous history of VTE, were recruited as controls.

RESULTS

A total of 44 subjects completed thrombophilia screening, of whom 5 (11%) were confirmed to have thrombophilia [protein C (PC) deficiency (2), protein S (PS) deficiency (1), combined PC & PS deficiency (1) and antithrombin III deficiency (1)]. Homozygous 5,10-methylenetetrahydrofolate reductase (C677T) gene mutation was found in 6 (14%) subjects but not in the controls. There was no antiphospholipid syndrome, activated PC resistance, factor V Leiden or prothrombin gene mutations.

CONCLUSION

In the Chinese population, PS and PC deficiencies are common thrombophilia for VTE during pregnancy and thrombophilia screening should be recommended in all pregnant women who suffer from VTE.

Venous thromboembolism and ethnicity

Venous thromboembolism (VTE) has long been considered a disease that affects predominantly white populations, a misconception resulting from a paucity of epidemiological data from non-Western countries, and the low incidence of hereditary thrombophilia in those of non-Caucasian background. Over the last decade, interest has grown in this area with the emergence of evidence that VTE is as prevalent, if not more so, in the black population and is also common in Asian groups. Much is still to be learned, as our current knowledge of hereditary thrombophilia and acquired risk factors do not fully explain the risk of VTE in non-Caucasian groups. This review summarises the current understanding of ethnic variation in VTE and highlights the need for further research in this area.

Homozygosity for the C46T polymorphism of the F12 gene is a risk factor for venous thrombosis during the first pregnancy

BACKGROUND

A first thromboembolic event during pregnancy and puerperium is predisposed to by polymorphisms G1691A in the factor V gene (F5) (F5G1691A) and G20210A in the prothrombin gene (F2) (F2G20210A).

OBJECTIVES

To study another potentially frequent thrombogenic polymorphism, C46T in the factor XII gene (F12) (F12C46T).

PATIENTS AND METHODS

The 32 463 previously asymptomatic women included in the NOHA First cohort in their first pregnancy were investigated for these three polymorphisms. No other constitutional or acquired thrombophilic risk factor was studied.

RESULTS

The overall incidence--absolute risk--of venous thromboembolic events (VTE) was 127 per 100,000 woman-years and was reduced to 22 per 100,000 women-years in women negative for the three polymorphisms (P < 0.0001). Homozygosity for F12C46T was associated with a significant relative risk (RR) of VTE [RR: 5.99, 95% confidence interval (95% CI): 2.1-17.3, P = 0.001], as was heterozygosity for F5G1691A (RR: 18.7, 95% CI: 8.3-42, P < 0.0001), heterozygosity for F2G20210A (RR: 14.3, 95% CI: 6.2-33.2, P < 0.0001), maternal age (RR: 1.18, 95% CI: 1.07-1.29, P = 0.0006), maternal body mass index (RR: 1.31, 95% CI: 1.11-1.55, P = 0.002), conceptus weight (percentiles adjusted for term of delivery; RR: 0.90, 95% CI: 0.88-0.93, P < 0.0001) and pre-eclampsia (RR: 3.03, 95% CI: 1.06-8.69, P = 0.039).

CONCLUSIONS

Homozygosity for the C46T polymorphism of the F12 gene is associated with venous thrombosis during the first pregnancy/puerperium in previously asymptomatic women.

Diagnosis of deep vein thrombosis and pulmonary embolism in pregnancy: a systematic review

INTRODUCTION

Diagnosing deep vein thrombosis (DVT) and pulmonary embolism (PE) in pregnancy is challenging. Many of the common diagnostic tests, including compression ultrasonography (CUS), ventilation-perfusion scintigraphy (VQ scan) and helical computed tomography (hCT) that have been extensively investigated in non-pregnant patients, have not been appropriately validated in pregnancy. Extrapolating results of diagnostic studies of DVT and PE in non-pregnant patients to those who are pregnant may not be correct because during pregnancy, physiologic and anatomic changes may affect diagnostic test results, presentation and natural history of VTE.

METHODS

We performed a systematic analysis of published studies addressing accurate diagnostic testing for DVT and PE in pregnancy to determine the accuracy of these tests in pregnancy.

RESULTS

Our initial search yielded 530 articles of which four remained for inclusion, three studies investigating diagnostic testing in patients with a clinical suspicion of DVT or PE and one study in patients with a clinical suspicion of PE.

CONCLUSIONS

From our systematic analysis of published studies investigating diagnostic testing for a clinical suspicion of DVT in pregnancy we conclude that; (i) two studies support withholding anticoagulant therapy in pregnant women with a clinical suspicion of DVT and normal results on serial IPG (impedance plethysmography), however, IPG is no longer used; (ii) one study demonstrated that a normal CUS at presentation combined with a normal D-dimer test or an abnormal D-dimer test combined with normal serial CUS appears promising for safely excluding DVT in pregnant patients, but too few patients were included in this pilot-study to draw firm conclusions; and (iii) one study investigated pregnant patients with a clinical suspicion of PE and this study concluded that in patients with normal or non-diagnostic VQ scans, withholding anticoagulant therapy might be safe, but this needs confirmation in larger studies. Recommendations on diagnostic testing of pregnant patients with a clinically suspected DVT or PE are provided.

Pulmonary thromboembolism in Asians/Pacific Islanders in the United States: analysis of data from the National Hospital Discharge Survey and the United States Bureau of the Census

PURPOSE

To assess the rate of diagnosis of deep venous thrombosis, pulmonary embolism, and venous thromboembolism; the incidence in hospitalized patients; and mortality from pulmonary embolism among Asians/Pacific Islanders in the United States.

METHODS

The number of patients discharged from hospitals with a diagnostic code for pulmonary embolism or deep venous thrombosis from 1990 through 1999 was obtained from the National Hospital Discharge Survey. Population estimates and deaths from pulmonary embolism from 1990 through 1998 were obtained from the United States Bureau of the Census.

RESULTS

Rate ratios of 10-year age-adjusted rates of diagnosis of deep venous thrombosis, pulmonary embolism, and venous thromboembolism comparing Asians/Pacific Islanders with whites and African Americans ranged from 0.16 to 0.21. Rate ratios comparing incidences in hospitalized patients ranged from 0.32 to 0.42. The age-adjusted rate ratio of mortality in "others" (which included Asians/Pacific Islanders) was 0.29 (95% confidence interval [CI]: 0.01 to 0.87) compared with whites and 0.14 (95% CI: 0.0 to 0.58) compared with African Americans.

CONCLUSION

Rates of deep venous thrombosis, pulmonary embolism, and venous thromboembolism; incidences in hospitalized patients; and the mortality rate from pulmonary embolism were markedly lower in Asians/Pacific Islanders than in whites and African Americans. Clinical assessment of the prior probability of venous thromboembolic disease at the bedside should probably be adjusted based on these ethnic differences.

Postoperative venous thromboembolism in Asia: a critical appraisal of its incidence

OBJECTIVES

Venous thromboembolism (VTE) has historically been perceived to be a rare disorder in Asia. However, new evidence has emerged recently that contradicts this perception. The question of routine VTE prophylaxis has been hotly debated in Asia due to disagreement on its incidence. We reviewed and analysed studies on postoperative VTE in Asian patients to determine if the condition was indeed rare and if the routine prophylactic measures as recommended by internationally accepted guidelines should be adopted in Asia.

METHODS

A review of published reports, from 1966 to December 2002, on deep vein thrombosis (DVT) and pulmonary embolism (PE) in the Asian population was made. A literature search of studies published in English was conducted via a detailed MEDLINE search. Studies had to attain a minimum inclusion and quality criteria to be accepted for the review, including the diagnostic modality used for the diagnosis of VTE. The appraisal was carried out independently and accepted by at least two of the three authors. The study population was classified into orthopaedic and general surgical/colorectal groups.

RESULTS

Twelve orthopaedic publications reviewed revealed an incidence of postoperative DVT of 10% to 63%. Six general and colorectal surgical publications reported an incidence of DVT ranging from 3% to 28%. The incidence was slightly lower than the reported incidence of 40% to 80% following orthopaedic surgery and 28% to 44% following general surgical operations in studies reporting on Caucasian populations.

CONCLUSION

While there is a wide variation in the incidence of DVT and VTE as reported in the Asian population, these diseases are by no means rare. The wide variation could be due to the study designs, heterogeneity of the procedures performed and the application of different diagnostic criteria. Results based on prospective studies with objective diagnostic criteria confirm the incidence of VTE as common. Routine chemoprophylaxis must be seriously considered in high-risk patients.