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

The incidence and risk factors of proximal lower extremity deep vein thrombosis without pharmacologic prophylaxis in critically ill surgical Taiwanese patients: A prospective study

Background

Venous thromboembolism (VTE) in critically ill patients has been well-studied in Western countries. Many studies have developed risk assessments and established pharmacological protocols to prevent deep venous thrombosis (DVT). However, the DVT rate and need for pharmacologic VTE prophylaxis in critically ill Taiwanese patients are limited. This study aimed to prospectively determine the DVT incidence, risk factors, and outcomes in critically ill Taiwanese patients who do not receive pharmacologic VTE prophylaxis.

Methods

We conducted a prospective study in a surgical intensive care unit (SICU) of a tertiary academic medical center in Taiwan. Adult patients admitted to SICU from March 2021 to June 2022 received proximal lower extremities DVT surveillance with venous duplex ultrasound. No patient received pharmacologic VTE prophylaxis. The outcomes were the incidence and risk factors of DVT.

Results

Among 501 enrolled SICU patients, 21 patients (4.2%) were diagnosed with proximal lower extremities DVT. In a multivariate regression analysis, hypoalbuminemia (odd ratio (OR) = 6.061, 95% confidence interval (CI): 1.067-34.421), femoral central venous catheter (OR = 4.515, 95% CI: 1.547-13.174), ICU stays more than 10 days (OR = 4.017, 95% CI: 1.270-12.707), and swollen leg (OR = 3.427, 95% CI: 1.075-10.930) were independent risk factors for DVT. In addition, patients with proximal lower extremities DVT have more extended ventilator days (p = 0.045) and ICU stays (p = 0.044).

Conclusion

Our findings indicate critically ill Taiwanese patients have a higher incidence of DVT than results from prior retrospective studies in the Asian population. Physicians who care for this population should consider the specific risk factors for DVT and prescribe pharmacologic prophylaxis in high-risk groups.

Prevalence and risk factor of post-operative lower extremities deep vein thrombosis in patients undergoing gynecologic surgery: a single-institute cross-sectional study

Background and aim

The study of prevalence and risk factors of postoperative lower limb deep vein thrombosis (DVT) in Thai gynecologic patients was limited. The present study was conducted to evaluate this issue.

Methods

The patients were age > 15 years old without a history of DVT or pulmonary emboli (PE) scheduled for laparotomy or vaginal gynecologic surgery between May and November 2020 were invited to participate. All of these patients were scheduled for a complete duplex ultrasound to detect lower limb DVT 72 h before and within 14 days after the operation. The patients without DVT were scheduled for an interview by telephone about DVT symptoms 30 days after the operation. The clinical variables were compared using univariate and multivariate analysis to identify the independent factors related to the development of DVT.

Results

One hundred and twelve patients met the inclusion criteria. Of these patients, 44 cases (39.3%) were diagnosed as malignancy and 102 patients underwent a hysterectomy. Post-operative DVTs were detected in six patients (5.4%) and all except one had a malignancy. Thus, the prevalence of DVT in malignancy cases was five in 44 patients (11.4%). The independent risk factors for postoperative DVT were age > 60-year-old and receiving a perioperative blood transfusion. Five of six DVT patients received low molecular-weight heparin for treatment of DVT and none developed PE. The rest of the participants reported no symptom-related DVTs from the interview 30 days after the operation.

Conclusion

The prevalence of postoperative DVT in gynecologic patients was 5%, and the independent risk factors were elderly patients and receiving a perioperative blood transfusion.

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.

Incidence, clinical characteristics and long-term prognosis of postoperative symptomatic venous thromboembolism: a retrospective cohort study

OBJECTIVES

The purpose of this study was to evaluate the incidence, clinical characteristics and prognosis of postoperative symptomatic venous thromboembolism (VTE) in Japan.

DESIGN

Retrospective observational study. Two data sets, Contemporary ManageMent AND outcomes in patients with Venous ThromboEmbolism (COMMAND VTE) Registry and Japanese Society of Anesthesiologists (JSA) annual report, were used for current analyses.

SETTING

Eighteen of 29 centres participated in the COMMAND VTE Registry.

PARTICIPANTS

Acute symptomatic patients with VTE who had undergone surgery 2 months prior to the diagnosis at 18 centres from January 2010 to December 2013 were identified in the COMMAND VTE Registry. From each centre's JSA annual report, the overall population that had received anaesthetic management during this period was retrieved.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the incidences and clinical characteristics of postoperative symptomatic VTE. The secondary outcomes were recurrent VTE, major bleeding and all-cause death.

RESULTS

We identified 137 patients with postoperative symptomatic VTE, including 57 patients with pulmonary embolism. The incidences of postoperative symptomatic VTE and pulmonary embolism were 0.067% and 0.028%, respectively, based on data from 2 03 943 patients who underwent surgery, managed by anaesthesiologists, during the study period. The incidences of postoperative symptomatic VTE varied widely, depending on surgical and anaesthetic characteristics. Postoperative symptomatic VTE occurred at a median of 8 days after surgery, with 58 patients (42%) diagnosed within 7 days. The cumulative incidence, 30 days after VTE, of recurrent VTE, major bleeding, and all-cause death was 3.0%, 5.2%, and 3.7%, respectively.

CONCLUSION

This study, combining the large real-world VTE and anaesthesiology databases in Japan revealed the incidence, clinical features and prognosis of postoperative symptomatic VTE, providing useful insights for all healthcare providers involved in various surgeries.

TRIAL REGISTRATION

Not applicable.

Prevalence and risk factors of venous thromboembolism in postoperative patients: A retrospective study

OBJECTIVE

To investigate the prevalence of and risk factors for Venous Thromboembolism (VTE) in postoperative patients.

METHODS

This descriptive, cross-sectional, retrospective study was conducted from August 2016 to October 2016 at two university hospitals and one public hospital. Total 217,354 patients records who underwent surgery in between 2010 and 2015 were examined. The study sample consisted of 123 patients who had postoperative venous thrombosis and pulmonary embolism, and whose discharge details, consultation data, diagnostic reports, and tests were examined in detail.

RESULTS

The prevalence of VTE in postoperative patients was 5.6/10,000. The mean age of the patients was 60.22±18.56 years. Of 123 patients, 51.20% were male, 30.90% were smokers, 46.30% had a comorbid disease, and 27.60% were diagnosed with cancer. Of the patients who had postoperative VTE, 65.0% had major surgery. Pharmacologic thromboprophylaxis was used in only 24.4% of patients (n=30).

CONCLUSION

The prevalence of VTE in the present study is lower than that in other studies. Because surgery is a risk factor for VTE, patients who will be operated should be assessed. Considering the present results, we can assume that patients' conditions are not being assessed appropriately. In addition, findings indicate that a standard for preventing VTE has not yet been established.

Compliance with an Enhanced Recovery After a Surgery Program for Patients Undergoing Gastrectomy for Gastric Carcinoma: A Phase 2 Study

BACKGROUND

Enhanced recovery after surgery (ERAS) programs have gained widespread acceptance in different fields of major surgery. However, most elements of perioperative care in ERAS are based on practices that originated from colorectal surgery. This study investigated compliance with the main elements of ERAS for patients undergoing gastrectomy for gastric carcinoma.

METHODS

This phase 2 study enrolled 168 patients undergoing elective gastrectomy for gastric carcinoma. An ERAS program consisting of 18 main elements was implemented, and compliance with each element was evaluated (ClinicalTrials.gov, NCT01653496).

RESULTS

Distal gastrectomy was performed for 142 patients (84.5%) and total gastrectomy for 26 patients (10.1%). Laparoscopic surgery was performed for 141 patients (86%). The postoperative morbidity rate was 9.5%, and the mortality rate was 0%. The rates of compliance with the 18 main elements of ERAS ranged from 88.1 to 100%. The lowest compliance rate was observed in the restriction of intravenous fluid element (88.1%). Overall, all ERAS elements were successfully applied for 122 patients (72.6%). In the multivariate analysis, the significant factors that adversely affected compliance with ERAS were surgery during the early study period [odds ratio (OR) 0.39; p = 0.038], open surgery (OR 0.15; p <0.001), and postoperative morbidity (OR 0.16; p = 0.003).

CONCLUSIONS

Most elements of ERAS can be successfully applied for patients undergoing gastrectomy for gastric carcinoma. Multimodal collaboration between providers is essential to achieve proper application of ERAS.

Nurses' objective knowledge regarding venous thromboembolism prophylaxis: A national survey study

Venous thromboembolism (VTE) is a common vascular disorder with high mortality and morbidity. Clinical nurses are a pivotal group that can serve as first-line health care providers. Lack of knowledge about VTE is an important barrier to effective nursing performance. This study aimed to determine nurses' knowledge of VTE prophylaxis through a nationwide survey across China, to understand gaps between current knowledge, and guidelines, and to help improve clinical nursing.The survey included 5 topics with 68 items on VTE, including basic knowledge, risk assessment, basic prophylaxis, physical prophylaxis, and pharmacological prophylaxis.The survey was distributed to 106 AAA-grade hospitals throughout China; 5218 valid questionnaires were submitted for analysis. There were 5097 women and 121 men respondents, with average age 30.29 ± 8.60 years. The average rate of correct responses regarding VTE knowledge was 59.90 ± 15.63%; 77.81% of subjects answered more than half of the survey items correctly. Better knowledge about thromboprophylaxis was observed among nurses who were more highly educated, more experienced, had received continuing education, intensive care unit (ICU), and lead nurses. Correct response rates were 68.39 ± 17.03%, 60.35 ± 21.01%, 75.51 ± 22.85%, 41.72 ± 17.47%, and 46.01 ± 21.22% for basic knowledge, risk assessment, basic prophylaxis, physical prophylaxis, and pharmacological prophylaxis, respectively.Respondents showed satisfactory results regarding basic prophylaxis, basic knowledge, and risk assessment for VTE; respondents had poorer knowledge regarding physical and pharmacological prophylaxis. Better mastery of knowledge about thromboprophylaxis was observed among nurses who were more highly educated, more experienced, had received continuous education, ICU, and lead nurses.This study suggested that nurse trainers should develop comprehensive educational programs that focus on low correct rate aspects. Higher-level continuous education could improve nurses' knowledge of thromboprophylaxis.

Effect of low molecular weight heparin on venous thromboembolism disease in thoracotomy patients with cancer

Background

Much attention has been given to venous thromboembolism (VTE) disease, and many guidelines for prophylaxis have been published. However, there are few published data on patients who underwent thoracotomy. This study is to compare the effect of low molecular weight heparin (LMWH) combined mechanical approaches with mechanical approaches alone in prevention of VTE in the post thoracotomy cancer patients.

Methods

This study used a prospective, randomized-controlled design. Patients with cancer who were scheduled for thoracotomy were divided into two groups: group A and group B. In group A, patients were given intermittent pneumatic compression (IPC) and elastic stockings (ES) postoperatively. Additionally, at 24 hours post-operation, patients were subcutaneously injected with LMWH calcium (nadroparin calcium; GlaxoSmithKline, China) for 7 days. In group B, patients were only given postoperative IPC and ES. The primary end points were incidence of pulmonary embolism (PE), deep vein thrombosis (DVT), and the PE severity index (PESI) of PE patients. The secondary end points were hemoglobin (HGB), platelet (PLT), D-dimer, the PO2/FiO2 ratio (P/F) at postoperative day (POD) 7, the chest drainage time (CDT) and the length of stay (LOS) in hospital after operation.

Results

A total of 90 patients were included in the final data analysis (40 patients in group A and 50 patients in group B). At POD7, the incidence of PE, DVT and PESI was 17.50%, 5.00% and 102.14±9.87, respectively, in group A. And 8.00%, 8.00% and 97.00±4.24, respectively, in group B. There were no significant differences between two groups (all P values were >0.05). There were no significant differences of HGB, PLT, D-dimer and P/F between two groups at the 7th day post operation (all P value >0.05).

Conclusions

LMWH combined mechanical prophylaxis did not significant reduced the rate of VTE in thoracotomy cancer patients.

The diagnosis and treatment of venous thromboembolism in asian patients

Although the incidence of venous thromboembolism (VTE) in Asian populations is lower than in Western countries, the overall burden of VTE in Asia has been considerably underestimated. Factors that may explain the lower prevalence of VTE in Asian populations relative to Western populations include the limited availability of epidemiological data in Asia, ethnic differences in the genetic predisposition to VTE, underdiagnoses, low awareness toward thrombotic disease, and possibly less symptomatic VTE in Asian patients. The clinical assessment, diagnostic testing, and therapeutic considerations for VTE are, in general, the same in Asian populations as they are in Western populations. The management of VTE is based upon balancing the treatment benefits against the risk of bleeding. This is an especially important consideration for Asian populations because of increased risk of intracranial hemorrhage with vitamin K antagonists. Non-vitamin K antagonist oral anticoagulants have shown advantages over current treatment modalities with respect to bleeding outcomes in major phase 3 clinical trials, including in Asian populations. Although anticoagulant therapy has been shown to reduce the risk of postoperative VTE in Western populations, VTE prophylaxis is not administered routinely in Asian countries. Despite advances in the management of VTE, data in Asian populations on the incidence, prevalence, recurrence, risk factors, and management of bleeding complications are limited and there is need for increased awareness. To that end, this review summarizes the available data on the epidemiology, risk stratification, diagnosis, and treatment considerations in the management of VTE in Asia.

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.

Treating pulmonary embolism in Pacific Asia with direct oral anticoagulants

Pulmonary embolism (PE) is the principal preventable cause of in-hospital deaths. Prevalence of PE in Asians is uncertain but undoubtedly underestimated. Asians and Caucasians have similar non-genetic risk factors for PE, and there is mounting evidence that PE affects Asians much more commonly than previously supposed; incidence, especially among high-risk patients, may approach that in Caucasians. Furthermore, PE incidence in Asia is increasing, due to both increased ascertainment, and also population ageing and growing numbers of patients with predisposing risk factors. Despite being warranted, thromboprophylaxis for high-risk patients is not routine in Pacific Asian countries/regions. There also appears to be scope to implement venous thromboembolism (VTE) management guidelines more assiduously. Anticoagulants, primarily heparins and warfarin, have been the mainstays of VTE management for years; however, these agents have limitations that complicate routine use. The complexity of current guidelines has been another barrier to applying evidence-based recommendations in everyday practice. Updated management approaches have considerable potential to improve outcomes. New oral anticoagulants that are easier to administer, require no, or much less, monitoring or dose-adjustment and have a favourable risk/benefit profile compared with conventional modalities, may offer an alternative with the potential to simplify VTE management. However, more information is required on practical management and the occurrence and treatment of bleeding complications. Increasing recognition of the burden of PE and new therapeutic modalities are altering the VTE management landscape in Pacific Asia. Consequently, there is a need to further raise awareness and bridge gaps between the latest evidence and clinical practice.

Incidence of venous thromboembolism in different ethnic groups: a regional direct comparison study

BACKGROUND

There are few studies that directly compare the variation in incidence of venous thromboembolism (VTE) according to ethnicity.

OBJECTIVE

The aim of this study was to compare the rates of VTE, deep venous thrombosis (DVT) and pulmonary embolism (PE) among different ethnic groups.

METHOD

The cases diagnosed with VTE, DVT and PE for a period between March 2004 and June 2009 were identified through the hospital-based database system. The 2006 New Zealand Census data were used to calculate the rate of diagnosis.

RESULTS

The observed annual incidence of VTE during this period was 81.6 per 100000 population. The relative risks of VTE when comparing European subjects with Maori, Pacific Island and Asian subjects after age standardization were 1.98 (95% confidence interval [CI], 1.63-2.41), 3.22 (95% CI, 2.60-3.99) and 4.02 (95% CI, 3.34-4.84), respectively. Relative risks of DVT after age standardization when comparing European subjects with Maori, Pacific Island and Asian subjects, were 2.14 (95% CI, 1.72-2.66), 3.20 (95% CI, 2.46-4.17) and 4.75 (95% CI, 3.80-5.94), respectively. Indirect age standardization was used for comparison of the diagnosis of PE. The ratio between the calculated expected number of cases and the actual number of cases was 1.32 (95% CI, 0.89-1.75) for Maori subjects, 2.96 (95% CI, 1.89-4.03) for Pacific Islanders and 3.89 (95% CI, 3.00-4.78) for Asians.

CONCLUSION

Europeans have a significantly higher incidence of VTE compared with Maori, Pacific Island and Asian populations.

Low molecular-weight heparin for thromboprophylaxis in patients undergoing gastric cancer surgery: an experience from one Korean institute

Purpose

This study evaluated the efficacy for preventing venous thromboembolism (VTE) and adverse effects of low-molecular-weight heparin (LMWH) in order to launch a prospective clinical trial in Korea.

Methods

We reviewed the medical records of 108 consecutive patients who underwent gastric cancer surgery. These patients were divided into 2 groups according to the type of thromboprophylaxis: group A, LMWH combined with intermittent pneumatic compression (IPC); group B, IPC alone. The postoperative outcomes of the two groups were compared.

Results

Symptomatic VTE was observed in only 1 patient (0.9%) from group B. Postoperative bleeding was more common in group A than in group B (10.9% vs. 7.5%), although the difference was not significant (P = 0.055). Most bleeding episodes were minor and managed conservatively without intervention. Only a high body mass index was associated with a significantly increased risk of postoperative bleeding (odds ratio, 1.45; 95% confidence interval, 1.12-2.43; P = 0.051).

Conclusion

A 40 mg of enoxaparin sodium is a safe and feasible dose for prevention of VTE. With the results of this study, we are planning a prospective randomized clinical trial to investigate the clinical efficacy of LMWH thromboprophylaxis in gastric cancer patients in Korea.

Idraparinux or idrabiotaparinux for long-term venous thromboembolism treatment: a systematic review and meta-analysis of randomized controlled trials

Background

Venous thromboembolism (VTE) is a prevalent disease with potential serious consequences. Idraparinux and idrabiotaparinux are two kinds of long-acting pentasaccharides. Evidence has shown that idraparinux and idrabiotaparinux are effective anticoagulants. However, up to now, there is no consensus on whether they are better than other anticoagulation methods for long-term VTE treatment.

Objective

To evaluate the effect of idraparinux or idrabiotaparinux versus other anticoagulation methods for long-term VTE treatment.

Methods

We searched Cochrane Central Register of Controlled Trials, PubMed, Embase, Web of science, clinical trial registry web sites (clinical trials,WHO clinical trial registry), Googlescholar, PubMed related articles and companies' web sites electronically up to Dec 30^th, 2012 and manually searched the reference lists and conference proceedings. Only randomized controlled trial (RCT) involving adult patients comparing idraparinux and/or idrabiotaparinux versus other anticoagulation methods for long-term VTE treatment was included. Two reviewers evaluated the studies and extracted data independently. Pooled risk ratios (RRs) were calculated as outcome measures and Revman 5.2 software was used to analyze data. Our primary efficacy and safety outcomes were the recurrent VTE and major bleeding rates.

Results

We included four RCTs and involved 8584 participants on idraparinux or idrabiotaparinux versus standard warfarin for VTE treatment from 9364 references. We did not perform meta-analysis on the VTE rate because of the significant heterogeneity. We used the fixed effect model to analyze the safety outcomes and demonstrated that idraparinux or idrabiotaparinux decreased major bleeding rate significantly (RR 0.73, 95% CI 0.54 to 0.98, P = 0.04) but had a trend to increase the all cause mortality (RR 1.26, 95% CI 1.00 to 1.57, P = 0.05) compared with warfarin.

Conclusions

Until now there is not sufficient evidence to clarify whether idraparinux or idrabiotaparinux is as effective and safe as the standard warfarin treatment for VTE treatment.

Symptomatic venous thromboembolism in Asian major trauma patients: incidence, presentation and risk factors

BACKGROUND

Trauma patients are known to be at increased risk of venous thromboembolism (VTE), and pulmonary embolism (PE) is one of the preventable causes of mortality in trauma patients. The incidence of VTE in Asian populations was believed to be lower than in Caucasians, but the recent literature suggests that this is not the case. The purpose of this study was to assess the incidence of VTE in Asian major trauma patients and to examine the manner of presentation, use of prophylaxis and risk factors for VTE. While other studies of VTE have addressed general and high-risk populations within Asia, our study is one of the few to examine Asian major trauma patients.

METHODS

Data for all patients with VTE were extracted from the Singapore General Hospital trauma database over a 10-year period from 1998 to 2007. Patient profiles and clinical factors were compared to patients without a diagnosis of VTE admitted with injuries in the same time period.

RESULTS

There were 8,615 patients entered into our database in this 10-year period. Thirty-four patients had VTE, with an overall incidence of 0.39 %. Thirteen patients had pulmonary embolism, an incidence of 0.15 %. Of note, 30 % of patients with deep vein thrombosis (DVT) presented with fever alone without limb symptoms. Almost all 34 patients who developed VTE had either head injury, a spinal cord injury or a pelvic/extremity injury. Eighteen patients had head injury, 22 patients sustained pelvic or extremity injury, and three patients had spinal cord injury with paraplegia. Head injury and spinal cord injury with neurologic sequelae were statistically significant risk factors for VTE (p < 0.05).

CONCLUSION

The incidence of symptomatic VTE in the Asian trauma population is no lower than in the West. The incidence found in this study is similar to the incidence of VTE according to a study using data from the American national trauma data bank using similar study methods and with a similar study population. It is also higher than the incidence in the literature for general post-surgical Asian patients. Fever was the presenting factor in some patients and screening for VTE should not be forgotten when assessing fever in the trauma patient. The strong association between head injury, spinal cord injury and VTE confirms that we should pay special attention to VTE prophylaxis for our patients with these injuries.

A prospective study on the incidence of postoperative venous thromboembolism in Korean gastric cancer patients: an inquiry into the application of Western guidelines to Asian cancer patients

Several Western guidelines recommend the routine use of pharmacologic thromboprophylaxis for cancer surgery patients to prevent venous thromboembolism (VTE). However, the necessity of routine pharmacologic perioperative thromboprophylaxis in Asian gastric cancer (GC) patients has not been clearly determined. To determine the necessity of routine perioperative pharmacologic thromboprophylaxis in Korean gastric cancer patients, the incidence of postoperative VTE was prospectively evaluated in gastric cancer patients receiving surgery. Among 610 GC patients who had received surgery, 375 patents underwent routine duplex Doppler ultrasonography (DUS) on days 5–12 following surgery to detect VTE and then VTE-related symptoms and signs were checked at 4 weeks after surgery (cohort A). The 235 patients that declined DUS were registered to cohort B and the occurrence of postoperative VTE was retrospectively analyzed. In cohort A, symptomatic or asymptomatic VTE until 4 weeks after surgery was detected in 9 patients [2.4%; 95% confidence interval (CI); 0.9–3.9]. Tumor stage was a significant factor related to VTE development [stage I, 1.4%; stage II/III, 2.4%; stage IV, 9.7% (P = 0.008)]. In multivariate analysis, patients with stage IV had a higher postoperative VTE development [odds ratio, 8.18 (95% CI, 1.54–43.42)] than those with stage I. In cohort B, a low incidence of postoperative VTE was reaffirmed; only one postoperative VTE case (0.4%) was observed. In conclusion, the incidence of postoperative VTE in Korean GC patients was only 2.4%. Risk-stratified applications of perioperative pharmacologic thromboprophylaxis are thought to be more appropriate than the routine pharmacologic thromboprophylaxis in Korean GC patients receiving surgery.

Efficacy and safety of low molecular weight heparin prophylaxis for venous thromboembolism following lumbar decompression surgery

OBJECTIVE

To evaluate the efficacy and safety of low molecular weight heparin (LMWH) prophylaxis for venous thromboembolism (VTE) after lumbar decompression surgery.

METHODS

Patients at high or the highest risk of VTE who underwent lumbar spine surgery in Peking Union Medical College Hospital from January 2004 to April 2011 were included in the present study. All the patients received a half dose of LMWH 6 hours after surgery followed by a full dose LMWH once per day until discharge. We recorded incidences of deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding complications, and medication side effects.

RESULTS

Seventy-eight consecutive patients were eligible and enrolled in this study. The mean hospital stat was 8.5±4.5 days. No symptomatic DVT, PE, or major bleeding events were observed. One patient developed wound ecchymosis, another developed wound bleeding, four had mild hepatic aminotransferase level elevation, and one developed a suspicious allergic reaction.

CONCLUSION

LMWH may be applied as an effective and safe prophylaxis for VTE in high-risk patients undergoing lumbar decompression surgery.

Systematic review and meta-analysis on the rate of postoperative venous thromboembolism in orthopaedic surgery in Asian patients without thromboprophylaxis

BACKGROUND

Postoperative venous thromboembolism (VTE) is a common life-threatening complication after surgery. This review analysed the rate and mortality of VTE after orthopaedic surgery in Asia.

METHODS

Inclusion criteria were: prospective study; deep vein thrombosis (DVT) diagnosed by venography or ultrasonography; hip fracture surgery (HFS), total hip arthroplasty (THA) or total knee arthroplasty (TKA); and no thromboprophylaxis. The pooled proportion was back-calculated by Freeman-Tukey variant transformation, using a random-effects model.

RESULTS

Twenty-two studies (total population 2454) published from 1979 to 2009 were included. Using venography, the pooled rates of all-site, proximal, distal and isolated distal DVT were 31·7, 8·9, 22·5 and 18·8 per cent respectively. With duplex ultrasonography, the respective rates were 9·4, 5·9, 5·9 and 5·8 per cent. After THA or HFS, using venography, the pooled rates of all-site and proximal DVT were 25·8 and 9·6 per cent; with ultrasonography, the respective rates were 10·8 and 7·2 per cent. In TKA groups, using venography, the pooled rates of all-site and proximal DVT were 42·5 and 8·7 per cent; with ultrasonography, the respective rates were 9·5 and 5·2 per cent. The overall pooled rates of symptomatic DVT and symptomatic pulmonary embolism (PE) were 4·5 and 0·6 per cent. No patient died from PE (pooled rate 0·2 per cent).

CONCLUSION

None of these Asian patients undergoing orthopaedic surgery died from VTE. Pooled rates of proximal and symptomatic DVT were lower than in Western reports.

The effect of low molecular weight heparin thromboprophylaxis on bleeding complications after gastric cancer surgery

BACKGROUND

Low molecular weight heparin (LMWH) has been widely used to prevent venous thromboembolism in cancer surgical patients. However, relatively few studies have examined the safety aspects related to the use of LMWH after abdominal cancer surgery. This study was designed to investigate the relationship between bleeding complications and LMWH thromboprophylaxis after gastric cancer surgery.

METHODS

From March to July in 2009, 179 consecutive patients who underwent gastric cancer surgery at our institution were administered LMWH (3200 U once daily from 2 to 6 h before surgery until discharge) perioperatively. A total of 182 patients consecutively treated before the introduction of LMWH prophylaxis were selected as controls.

RESULTS

There were 234 men and 127 women (mean age, 60 +/- 12 years). No significant intergroup differences were observed with respect to clinicopathological features and operative procedures. No patient in the LMWH or control group developed symptomatic venous thromboembolism postoperatively. However, the LMWH group had a significantly higher surgical complication rate (27.4 versus 15.4%, P = 0.005). Among the surgical complications, postoperative bleeding and wound complications were significantly higher in the LMWH group, whereas other complications were similar in the two study groups. Multivariate analysis showed that LMWH administration was an independent risk factor (odds ratio, 2.83; 95% confidence interval, 1.28-6.23, P = 0.009) of postoperative bleeding.

CONCLUSIONS

LMWH thromboprophylaxis was found to increase significantly the risk of bleeding complications after gastric cancer surgery. Optimal LMWH prophylaxis regimens, including the dosage and timing of treatment commencement, for gastric cancer surgery should be determined in further clinical trials.

Venous Thromboembolism at the National Healthcare Group, Singapore

Introduction: Venous thromboembolism (VTE), including its most serious clinical subtype, pulmonary embolism (PE), is a potentially preventable disease. While current assessment tools do not include ethnicity as a risk factor, studies suggest that Asians have lower risk of VTE compared to Caucasians. This study aims to describe 2006 in-hospital and projected population- based incidence rates of VTE and PE in Singapore. Materials and Methods: Data on 2006 admissions at 3 major NHG hospitals, cases of VTE and their demographics were obtained from the ODS, a large administrative database of the National Healthcare Group (NHG). Demo- graphic characteristics of the 2006 Singapore resident population were obtained from the 2006 Singapore Statistics website. Results: In 2006, there were 860 cases of VTE out of 98,121 admissions in these 3 hospitals. Overall and secondary VTE age adjusted in-hospital burden was 73 and 54 per 10,000 patients, respectively. Caucasians and Eurasians had VTE rates in excess of 100 per 10,000 while Chinese, Malays and Indians each had rates below 100 per 10,000. Assuming that 42.5% of the 2006 Singapore population was served by NHG, the estimated population-based incidence of VTE and PE is 57 and 15 per 100,000, respectively. Conclusions: As patterns across ethnic groups point to lower VTE rates among Asians compared to Caucasians and Eurasians, analytic studies should be considered to test this hypothesis. There may be a need to develop locally applicable risk assessment tools which can be used to support local guidelines for VTE prophylaxis, thus leading to more acceptable and cost-effective care. Key words: Epidemiology, Prevention, Pulmonary embolism

Metabolic syndrome is associated with venous thromboembolism in the Korean population

BACKGROUND

The metabolic syndrome (MS) is a known risk factor for arterial thromboembolism. Preliminary reports have also suggested the association between MS and venous thromboembolism (VTE).

METHODS AND RESULTS

In this case-control study, we investigated the association between MS and VTE in Korean patients. Patients with objectively diagnosed VTE and healthy control subjects underwent clinical assessment for the presence of MS according to the National Cholesterol Education Adult Treatment Panel III criteria modified with body mass index (WHO Asian Pacific Perspective, 2000). The presence of known risk factors for VTE was ascertained. Patients with VTE secondary to cancer were excluded. The prevalence of MS was compared between VTE group and controls. Two hundred eight VTE patients and 300 controls were assessed. VTE was idiopathic in 91 patients and secondary to a known risk factor in 117. The prevalence of MS was significantly higher in VTE patients (47.6%) than in controls (37.7%) (OR: 1.50; 95% CI: 1.05 to 2.15, P=0.026). After adjusting for age, sex, and smoking status, metabolic MS remained independently associated with VTE (OR: 1.56; 95% CI: 1.07 to 2.27, P=0.020). In the subgroup analysis, MS was also independently associated with idiopathic VTE (OR: 1.71; 95% CI: 1.04 to 2.81, P=0.033), but not with secondary VTE (OR: 1.43; 95% CI: 0.91 to 2.99, P=0.121). Multivariate analysis demonstrated that high BMI (OR: 1.70, 95% CI: 1.01 to 2.87), decreased HDL cholesterol (OR: 1.99, 95% CI: 1.17 to 3.39), and elevated fasting glucose levels (OR: 2.31; 95% CI: 1.35 to 3.94) were associated with idiopathic VTE.

CONCLUSION

MS is associated with VTE and in particular with idiopathic VTE in the Korean population.

Venous thromboembolism in acute spinal cord injury patients

BACKGROUND

The western literature on deep vein thrombosis (DVT) and pulmonary embolism (PE) following spinal cord injury (SCI) report an alarmingly high incidence, necessitating thromboprophylaxis. The literature on incidence from the Asian subcontinent is scanty and from India is almost nonexistent.

MATERIALS AND METHODS

Seventy hospitalized acute SCI patients presenting within five days of the injury were included in the present analysis. Forty-two cases were subjected to color Doppler studies and 28 cases had to be subjected to venography due to lack of facility at some point of time. The clinical course of the patients was closely observed during the period of hospitalization. All except 14 were managed nonoperatively. Thromboprophylaxis was not given to any patient at any stage; however, treatment was instituted in those showing the features of DVT on investigations.

RESULTS

Twelve patients died during the period of hospitalization. Deep vein thrombosis could be detected in seven patients only, three in the proximal and four in the distal segment of the lower limb and of these three died. Based on the clinical course and positive investigation report in favor of DVT, we presumed that the cause of death in these three patients was pulmonary embolism. In the other nine, in the absence of an autopsy report, the cause of deaths was considered as pulmonary infection, asphyxia, diaphragmatic paralysis, hematemesis, cervicomedullary paralysis etc. Clinical features to diagnose DVT were of little help.

CONCLUSIONS

There is a much lower incidence (10%) of DVT and PE following spinal cord injury (SCI) in India than what is reported from the western countries. Higher age group and quadriplegia were the only factors which could be correlated. Deep vein thrombosis extending proximal to the knee was significant. In the absence of autopsy and other screening tests like D-dimer test or 125I fibrogen uptake study, the true incidence of venous thromboembolism remains uncertain. Noninvasive screening of all patients for the detection of deep vein thrombosis in SCI patients is strongly recommended.

Assessment of total thrombus load in symptomatic patients with venous thromboembolism

Pulmonary embolism (PE) and Deep vein thrombosis (DVT) are separate but related aspects of the same dynamic process termed as venous thrombembolism (VTE). The existing Asian literature has shown a wide variation in the prevalence of VTE, with very limited data from the Indian subcontinent. Between January 2001 and July 2004, 1,552 patients with clinically suspected lower limb DVT underwent a combined ascending radionuclide venogram and lung perfusion scan for assessment of the total thrombus burden. Of 744 patients with radionuclide venography proven DVT, 294 (40%) had a high probability lung scan. Nearly half of these patients were asymptomatic for pulmonary embolism. The high prevalence of PE in patients with DVT suggests the need for evaluation of thrombus load in the venous as well as pulmonary circulation. A combination radionuclide ascending venography with lung perfusion scan is a useful and reliable single test for this purpose.

Pulmonary Embolism: A Frequent Occurrence in Indian Patients with Symptomatic Lower Limb Venous Thrombosis

OBJECTIVE

Pulmonary embolism (PE) is the most severe complication of deep venous thrombosis (DVT). There have been very few studies to assess the prevalence of PE in Asian patients. The objective of this study was to define the prevalence of PE in patients presenting with suspected lower limb DVT.

METHODS

This was a prospective cohort study at Sir Ganga Ram Hospital, a large multispecialty hospital in New Delhi, India. From January 2001 to July 2004, 1,552 consecutive inpatients and outpatients who presented with clinically suspected lower limb DVT were enrolled in the study. Combined ascending radionuclide venography and lung perfusion scan was performed in all patients. Patients with evidence of pulmonary perfusion defects underwent ventilation lung scan.

RESULTS

Radionuclide venography-detectable DVT was noted in 744 patients, of whom 521 (70%) had suprapopliteal DVT. Of patients with DVT, 294 (39.5%) showed a high-probability lung scan and 135 (18.1%) had an intermediate-probability lung scan. Overall, 47% of patients with a high-probability scan had no clinical manifestations suggestive of PE.

CONCLUSION

PE occurs frequently in Indian patients with symptomatic DVT. Increasing awareness will provide us with clearer ideas about the prevalence of venous thromboembolism in Asian countries.

Incidence of venous thromboembolism following major abdominal surgery: a multi-center, prospective epidemiological study in Japan

BACKGROUND

Venous thromboembolism (VTE) has been considered to be a rare surgical complication in Japan.

AIM

To investigate the incidence and risk factors of VTE in Japanese patients undergoing major abdominal surgery.

METHODS

A prospective, multi-center epidemiological study was conducted from December, 2001 to August 2002 in 39 medical institutes throughout Japan. A total of 173 patients with general (n = 128), gynecologic (n = 23), and urologic (n = 22) surgery were analyzed. For the diagnosis of deep vein thrombosis (DVT), bilateral venography was performed in all patients. Lung ventilation/perfusion scintigraphy was carried out in patients suspected of pulmonary thromboembolism (PTE).

RESULTS

There were 36 patients with distal DVT (20.8%) and five patients with proximal DVT (2.9%). One patient was diagnosed as PTE. Overall, VTE was diagnosed in 42 patients (24.3%). By univariate analysis, only age (60 years or older) was identified as a significant risk factor in the whole study population. When analyzed by the stepwise multiple logistic regression model, female gender, operation site, age, and operation time were four risk factors found to be significant. The incidence of VTE was closely related to the number of risk factors that patients had. As many as 44% of patients with three or four risk factors developed VTE while those with one or two risk factors showed about a 17% incidence of VTE. Four patients lacking any risk factors did not develop VTE.

CONCLUSIONS

Venous thromboembolism is common in Japanese patients undergoing major abdominal surgery. Pharmacologic thromboprophylaxis is considered essential, particularly in those patients with multiple, potential risk factors.