Incidence of symptomatic venous thromboembolism after different elective or urgent surgical procedures

Risk and incidence of perioperative deep vein thrombosis in patients undergoing gastric cancer surgery

BACKGROUND AND PURPOSE

Venous thromboembolism (VTE) is a potentially fatal perioperative complication. Understanding the risk factors for deep vein thrombosis (DVT) and initiating appropriate prophylaxis is pivotal for reducing the risk of VTE. The purpose of this study was to clarify the perioperative risk factors for DVT in patients undergoing surgery for gastric cancer.

METHODS

We reviewed the findings of lower limb ultrasonography performed in 160 patients who underwent gastrectomy for gastric cancer.

RESULTS

The preoperative and postoperative incidence of DVT was 4.4% (7/160) and 7.2% (11/153), respectively. All postoperative DVTs were of the distal type, whereas preoperative DVTs were of the proximal (n = 3) and distal type (n = 4). None of the patients suffered symptomatic VTE. Multivariate analysis indicated that depth of invasion and D-dimer concentration were independent risk factors for preoperative DVT and that gender and performance status were risk factors for postoperative DVT. Receiver operating characteristic analysis revealed that the optimal cut-off D-dimer concentration was 1.4 μg/mL.

CONCLUSIONS

The incidence of perioperative DVT was low for patients undergoing gastric cancer surgery. Therefore, the risk-stratified application of perioperative pharmacologic thromboprophylaxis is thought to be more appropriate than routine pharmacologic thromboprophylaxis for Japanese patients undergoing surgery for gastric cancer.

Risk factors associated with mortality from vascular thromboembolic events in patients diagnosed with non-small cell lung cancer: a population-based analysis

BACKGROUND

Lung cancer patients are at increased risk for vascular events possibly due to cancer induced hypercoagulation.

AIM

The purpose of this study was to evaluate risk factors associated with the mortality from vascular thromboembolic events in patients diagnosed with non-small cell lung cancer (NSCLC).

DESIGN

Retrospective population-based analysis.

METHODS

We used Surveillance, Epidemiology and End Results Program for 2004-13 and evaluated 199 337 patients with NSCLC. Univariate and multivariate subdistribution hazard regression models were used to identify potential risk factors for mortality from vascular thromboembolic events. Stratification analysis against clinical stage was performed to determine if the severity of the disease influenced the identified associations.

RESULTS

Multivariate Cox regression analysis demonstrated that increased risk of mortality due to vascular thromboembolic events was associated with age, black race, non-adenocarcinoma histology, surgical treatment alone (all, P < 0.001) and north central region of SEER registry (P = 0.003). Female gender (P < 0.001), Asian or Pacific Islander race (P = 0.001), multiple co-existing primary cancers and late cancer stages (both, P < 0.001) were associated with significantly lower risk of mortality due to vascular thromboembolic events. The significant predictors of mortality from the vascular thromboembolic event were dependent on the stages of the disease.

CONCLUSIONS

Risk factors associated with mortality from the vascular thromboembolic events in NSCLC patients identified in this study can promote awareness and may help to identify groups of patients that can benefit from anti-thrombotic prophylaxis measures.

Comparative efficacy and safety of anticoagulants for prevention of venous thromboembolism after hip and knee arthroplasty

Background and purpose - New oral anticoagulants have been developed to prevent venous thromboembolism (VTE) after knee or hip arthroplasty. Although there have been several network meta-analyses (NMA) to compare different regimens, an NMA including 2 different enoxaparin doses and edoxaban has not been performed. Methods - Standard NMA for fondaparinux, dabigatran, rivaroxaban, apixaban, edoxaban, and enoxaparin was performed. Outcome variables included a composite of total VTE and major/clinically relevant bleeding. The rank probabilities of each treatment outcome were summarized by the surface under the cumulative ranking curve. Results - Fondaparinux, rivaroxaban, and apixaban were associated with a reduced risk of VTE compared with enoxaparin, while dabigatran was not. None of these 3 drugs increased bleeding compared with enoxaparin 30 mg twice daily. However, fondaparinux and rivaroxaban increased bleeding compared with enoxaparin 40 mg once daily, while apixaban did not. Apixaban was even associated with decreased major/clinically relevant bleeding compared with enoxaparin 30 mg twice daily or 40 mg once daily. When edoxaban was included in the NMA, edoxaban decreased VTE and did not increase bleeding compared with enoxaparin. Interpretation - A higher efficacy of fondaparinux and rivaroxaban compared with enoxaparin was associated with increased bleeding tendency, while apixaban was superior to enoxaparin regarding both efficacy and safety. A clustered ranking plot showed that apixaban might be the most preferred regarding efficacy and safety. However, our results were driven by indirect statistical inference and were limited by the heterogeneity of the bleeding outcome definitions, drug initiation and continuation, and different surgery types.

Efficacy of intermittent pneumatic compression for venous thromboembolism prophylaxis in patients undergoing gynecologic surgery: A systematic review and meta-analysis

We sought to comprehensively assess the efficacy of Intermittent Pneumatic Compression (IPC) in patients undergoing gynecologic surgery. A computerized literature search was conducted in Pubmed, Embase and Cochrane Library databases. Seven randomized controlled trials involving 1001 participants were included. Compared with control, IPC significantly lowered the deep vein thrombosis (DVT) risk [risk ratio (RR) = 0.33, 95% confidence interval (CI): 0.16 – 0.66]. The incidence of DVT in IPC and drugs group was similar (4.5% versus. 3.99%, RR = 1.19, 95% CI: 0.42 – 3.44). With regards to pulmonary embolism risk, no significant difference was observed in IPC versus control or IPC versus drugs. IPC had a lower postoperative transfusion rate than heparin (RR = 0.53, 95% CI: 0.32 – 0.89), but had a similar transfusion rate in operating room to low molecular weight heparin (RR = 1.06, 95% CI: 0.69 – 1.63). Combined use of IPC and graduated compression stockings (GCS) had a marginally lower risk of DVT than GCS alone (RR = 0.38, 95% CI: 0.14 – 1.03). In summary, IPC is effective in reducing DVT complications in gynecologic surgery. IPC is neither superior nor inferior to pharmacological thromboprophylaxis. However, whether combination of IPC and chemoprophylaxis is more effective than IPC or chemoprophylaxis alone remains unknown in this patient population.

Epidemiology of venous thromboembolism in Africa: a systematic review

Essentials Venous thromboembolism (VTE) is among the three main causes of cardiovascular disease worldwide. This review is the first to summarize the epidemiology of VTE in African populations. The prevalence of VTE in Africa is high following surgery, in pregnancy and post-partum. At least one quarter of patients at risk of VTE in Africa are not receiving prophylaxis.

SUMMARY

Background Venous thromboembolism (VTE) is among the three leading causes of cardiovascular disease worldwide. Despite its high burden, there has been no previous study summarizing the epidemiology of VTE in African populations. Hence, we conducted this systematic review to determine the prevalence, incidence and mortality associated with VTE, and to evaluate the use of VTE prophylaxis in Africa. Methods We searched PubMed, Scopus and African Journals Online to identify articles published on VTE in Africa from inception to November 19, 2016, without language restriction. The reference list of eligible articles were further scrutinized to identify potential additional studies. Results Overall, we included 21 studies. The great majority of the studies yielded a moderate risk of bias. The prevalence of deep vein thrombosis (DVT) varied between 2.4% and 9.6% in postoperative patients, and between 380 and 448 per 100 000 births per year in pregnant and postpartum women. The prevalence of pulmonary embolism (PE) in medical patients varied between 0.14% and 61.5%, with a mortality rate of PE between 40% and 69.5%. The case-fatality rate after surgery was 60%. Overall, 31.7-75% of the patients were at risk of VTE, and between 34.2% and 96.5% of these received VTE prophylaxis. Conclusion The prevalence of VTE and associated mortality are high following surgery, and in pregnant and postpartum women in Africa. At least one-quarter of patients who are at risk for VTE in Africa are not receiving prophylaxis. These results are generated from studies with small sample size, highlighting an urgent need for well-designed studies with larger sample size to evaluate the true burden of VTE in Africa.

Trends in Perioperative Venous Thromboembolism Associated with Major Noncardiac Surgery

Background  Venous thromboembolism (VTE) is a common vascular complication of noncardiac surgery.

Methods  We evaluated national trends in perioperative in-hospital VTE incidence, management, and outcomes using a large database of hospital admissions from the United States. Patients aged ≥ 45 years undergoing major noncardiac surgery from 2005 to 2013 were identified from the National Inpatient Sample. In-hospital perioperative VTE was defined as lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE), and the incidence was evaluated over time. Multivariable regression models with demographics and comorbidities as covariates were generated to estimate adjusted odds ratios (aOR).

Results  Major noncardiac surgery was performed in 9,431,442 hospitalizations that met inclusion criteria, and perioperative VTE occurred in 99,776 patients (1,057 per 100,000), corresponding to an annual incidence of ≈53,000 after applying sample weights. Over time, perioperative VTE per 100,000 surgeries increased by 135 (95% confidence interval [CI]: 107–163), from 925 in 2005 to 1,060 in 2013 ( p for trend <0.001; aOR [for 2013 vs. 2005]: 1.22, 95% CI: 1.19–1.26), due to increases in nonfatal VTE rates (from 840 [per 100,000 surgeries] in 2005 to 987 in 2013; p for trend <0.001). Perioperative VTE occurred most frequently in patients undergoing thoracic (2.0%) and vascular surgery (1.8%). Mortality was higher in patients with VTE than those without VTE (aOR: 3.12, 95% CI: 3.05–3.20).

Conclusion  Perioperative VTE occurs in approximately 1% of patients ≥45 years undergoing major noncardiac surgery, with increasing incidence of nonfatal VTE over time.

Role of routine pre-operative screening venous duplex ultrasound in morbidly obese patients undergoing bariatric surgery

BACKGROUND/AIMS

It is well established that obesity is a strongly associated risk factor for post-operative deep vein thrombosis (DVT). Physical effects and pro-thrombotic, pro-inflammatory and hypofibrinolytic effects of severe obesity may predispose to idiopathic DVT (pre-operatively) because of which bariatric patients are routinely screened before surgery. The aim of this study was to audit the use of routine screening venous duplex ultrasound in morbidly obese patients before undergoing bariatric surgery.

METHODS

We retrospectively reviewed 180 patients who underwent bariatric surgery from August 2013 to August 2014 who had undergone pre-operative screening bilateral lower-extremity venous duplex ultrasound for DVT. Data were collected on patient's demographics, history of venous thromboembolism, prior surgeries and duplex ultrasound details of the status of the deep veins and superficial veins of the lower limbs.

RESULTS

No patients had symptoms or signs of DVT pre-operatively. No patient gave history of DVT. No patient was found to have iliac, femoral or popliteal vein thrombosis. Superficial venous disease was found in 17 (8%). One patient had a right lower limb venous ulcer.

CONCLUSION

Thromboembolic problems in the morbidly obese before bariatric surgery are infrequent, and screening venous duplex ultrasound can be done in high-risk patients only.

Cancer and Venous Thromboembolic Disease: A Review

Venous thromboembolism (VTE), including deep-vein thrombosis and pulmonary embolism, represents a major cause of morbidity and mortality in cancer patients. Patients with cancer are six times more likely to develop VTE than their noncancer counterparts, and VTE is the second leading cause of death in cancer patients. Despite the publication of major consensus guidelines setting out recommendations for thromboprophylaxis in cancer patients, there remains a gulf between these guidelines and clinical practice. In general, thromboprophylaxis is recommended for most patients hospitalized with active cancer. Furthermore, outpatient thromboprophylaxis may be used in carefully selected high-risk ambulatory patients. Certain areas of controversy still remain. Although low-molecular-weight heparin has been shown to be superior to vitamin K antagonists in cancer patients, the role of direct oral anticoagulants is still uncertain. Moreover, recurrent thromboembolism, bleeding, and thrombocytopenia are frequently seen in cancer patients. Optimal anticoagulation in such instances presents a major challenge to clinicians. Modern computed tomography techniques have resulted in an increase in the detection of "incidental" VTE. Despite a growing body of evidence promulgating standard anticoagulant treatment in such cases, these cases present further challenges for members of the multidisciplinary team. The Oncologist 2017;22:199-207Implications for Practice: This article discusses venous thromboembolism (VTE) in patients with malignancy. Practical guidance is offered on how to prevent, diagnose, and treat VTE in cancer patients. The management of "challenging" cases of VTE is also discussed.

Incidences and variations of hospital acquired venous thromboembolism in Australian hospitals: a population-based study

BACKGROUND

Data on hospital-acquired venous thromboembolism (HA-VTE) incidence, case fatality rate and variation amongst patient groups and health providers is lacking. We aim to explore HA-VTE incidences, associated mortality, trends and variations across all acute hospitals in New South Wales (NSW)-Australia.

METHODS

A population-based study using all admitted patients (aged 18-90 with a length of stay of at least two days and not transferred to another acute care facility) in 104 NSW acute public and private hospitals during 2002-2009. Poisson mixed models were used to derive adjusted rate ratios (IRR) in presence of patient and hospital characteristics.

RESULTS

Amongst, 3,331,677 patients, the incidence of HA-VTE was 11.45 per 1000 patients and one in ten who developed HA-VTE died in hospital. HA-VTE incidence, initially rose, but subsequently declined, whereas case fatality rate consistently declined by 22 % over the study period. Surgical patients were 128 % (IRR = 2.28, 95 % CI: 2.19-2.38) more likely to develop HA-VTE, but had similar case fatality rates compared to medical patients. Private hospitals, in comparison to public hospitals had a higher incidence of HA-VTE (IRR = 1.76; 95 % CI: 1.42-2.18) for medical patients. However, they had a similar incidence (IRR = 0.91; 95 % CI: 0.75-1.11), but a lower mortality (IRR = 0.59; 95 % CI: 0.47-0.75) amongst surgical patients. Smaller public hospitals had a lower HA-VTE incidence rate compared to larger hospitals (IRR < 0.68) but a higher case fatality rate (IRR > 1.71). Hospitals with a lower reported HA-VTE incidence tended to have a higher HA-VTE case fatality rate.

CONCLUSION

Despite the decline in HA-VTE incidence and case fatality, there were large variations in incidents between medical and surgical patients, public and private hospitals, and different hospital groups. The causes of such differences warrant further investigation and may provide potential for targeted interventions and quality improvement initiatives.

The identification of risk factors for venous thromboembolism in gastrointestinal oncologic surgery

BACKGROUND

The aim of this study was to examine the incidence and factors associated with occurrence of venous thromboembolism (VTE) in patients undergoing major gastrointestinal (GI) surgery for malignancy.

METHODS

The American College of Surgeon's National Surgical Quality Improvement Program, Participant User File database was queried from 2005 to 2012 to study major GI operations performed for cancer. Predictors of VTE and their relation to survival were studied.

RESULTS

In 79,300 patients, the incidence of deep venous thrombosis was 1.7%, and pulmonary embolism was 0.9% during the 30-d postoperative period. The highest rate of VTE occurred after esophagectomy (5.9%) followed by pancreatectomy (3.2%), hepatectomy (3.2%), gastrectomy (2.5%), enterectomy (2.3%), colectomy, and proctectomy (2.0%). On multivariate analysis, disseminated cancer, age ≥ 80 y, body mass index > 35 kg/m(2), functional status, post operative sepsis, pulmonary dysfunction, and longer operative time were associated with occurrence of VTE. Occurrence of VTE was associated with mortality on multivariate analysis (odds ratio 2.4, 95% confidence interval 2.0-3.0, P < 0.001).

CONCLUSIONS

Absolute incidence of VTE after major GI surgery is low but is associated with significant mortality and postoperative complications. Disseminated cancer, post operative sepsis, longer operative time, and increased body mass index >35 kg/m(2) further increased the risk of VTE in patients undergoing surgery for malignancy. Surveillance strategies should be implemented for those cancer patients who have multiple risk factors for VTE.

Is DVT prophylaxis necessary after oncology lower limb surgery? A pilot study

BACKGROUND

Deep vein thrombosis (DVT) has been independently associated with both malignant diseases and orthopaedic surgery. Therefore, orthopaedic oncology patients may be at a high risk for thromboembolic events. However, less emphasis is given to this group of patients compared to the patients undergoing total hip and knee replacement. The objective of this study is to determine the incidence of DVT and their risk factors in patients undergoing orthopaedic oncology lower limb surgery without prophylaxis.

QUESTIONS/PURPOSES

(1) What is the incidence of DVT in patients who underwent orthopaedic oncology surgery for the lower limb? (2) What are the risk factors related to DVT in patients who underwent oncology surgery of the lower limb surgery? (3) This is a pilot study to determine if further trial is warranted.

METHODS

This is a prospective study. All sequential patients undergoing orthopaedic oncology operations from the period of 1st October 2013 till 30th September 2014 were recruited for the study with their consent. Their demographic data, diagnosis and surgery were documented. Thirty-eight patients who underwent lower limb surgeries for orthopaedic oncology indications were included in the study. No tourniquet was used in these lower limb surgeries. There were 24 men and 14 women with a mean age of 36 years (11-75). All potential risk factors were also identified and documented. All patients were not given any form of DVT prophylaxis (mechanical and chemical) before and after operation as this is a standard protocol in our center and a Medical Ethics Committee approval was taken for this study. DVT surveillance was performed 1 day before operation and 2 weeks after operation with ultrasound Doppler. Patients diagnosed with DVT via ultrasound Doppler were subsequently scheduled for CTPA to look for pulmonary embolism (PE).

RESULTS

DVT was detected in two patients (5 %). Both patients were asymptomatic and they both had proximal thrombosis. One patient (2.6 %) was diagnosed with non-fatal PE and was asymptomatic. PE was detected incidentally by staging computed tomography scan and the patient had negative ultrasound Doppler of the operated and non-operated limb for DVT. We did not carry out a statistical analysis as the study population with DVT and pulmonary embolism is small.

CONCLUSIONS

The incidence of DVT in patients after undergoing orthopaedic oncology lower limb surgery was low even without prophylaxis at our center. Further investigation with larger sample size is needed to validate our results and identify the risk factors.

LEVEL OF EVIDENCE

Level III descriptive study.

Comparison of Venous Thromboembolism after Total Artificial Joint Replacement between Musculoskeletal Tumors and Osteoarthritis of the Knee by a Single Surgeon

The purpose of this study was to compare and evaluate the event of VTE (Venous Thromboembolism Event) after total artificial joint replacement between two groups diagnosed with either musculoskeletal tumors or osteoarthritis (OA) of the knee. From 2004 to 2014, a total of 1,402 patients (308 in tumor group, 1,094 in OA group) were involved in this study. The rate of asymptomatic DVT (Deep vein thrombosis) was significantly higher in tumor group when compared with OA group. Though both the incidence of symptomatic DVT and PE (Pulmonary embolism) were slightly higher in tumor group, no significant difference was detected. Tumor patients suffered an almost equal risk of VTE compared with OA patients except a higher rate of asymptomatic DVT after total artificial joint replacement. For patients with tumor, no significant association was observed between any potential risk factor and DVT.

Evaluating patient safety indicators in orthopedic surgery between Italy and the USA

OBJECTIVE

To compare patient safety in major orthopedic procedures between an orthopedic hospital in Italy, and 26 US hospitals of similar size.

DESIGN

Retrospective analysis of administrative data from hospital discharge records in Italy and Florida, USA, 2011-13. Patient Safety Indicators (PSIs) developed by the Agency for Healthcare Quality and Research were used to identify inpatient adverse events (AEs). We examined the factors associated with the development of each different PSI, taking into account known confounders, using logistic regression.

SETTING

One Italian orthopedic hospital and 26 hospitals in Florida with ≥ 1000 major orthopedic procedures per year.

PARTICIPANTS

Patients ≥ 18 years who underwent 1 of the 17 major orthopedic procedures, and with a length of stay (LOS) > 1 day.

INTERVENTION

Patient Safety management between Italy and the USA.

MAIN OUTCOME MEASURE

Patient Safety Indicators.

RESULTS

A total of 14 393 patients in Italy (mean age = 59.8 years) and 131 371 in the USA (mean age = 65.4 years) were included. US patients had lower adjusted odds of developing a PSI compared to Italy for pressure ulcers (odds ratio [OR]: 0.21; 95% confidence interval [CI]: 0.10-0.45), hemorrhage or hematoma (OR: 0.42; CI 0.23-0.78), physiologic and metabolic derangement (OR: 0.08; CI 0.02-0.37). Italian patients had lower odds of pulmonary embolism/deep vein thrombosis (OR: 3.17; CI 2.16-4.67) compared to US patients.

CONCLUSIONS

Important differences in patient safety events were identified across countries using US developed PSIs. Though caution about potential coding differences is wise when comparing PSIs internationally, other differences may explain AEs, and offer opportunities for cross-country learning about safe practices.

Assessing the risk for development of Venous Thromboembolism (VTE) in surgical patients using Adapted Caprini scoring system

AIM

To determine the incidence, morbidity and mortality due to Venous Thromboembolism (VTE) in surgical patients, and to assess the validity and reliability of Adapted Caprini scoring in risk stratification for VTE prophylaxis.

METHODOLOGY

This was a prospective observational study in a tertiary care hospital of South India on patients who underwent both elective and emergency surgeries over a period of 9 months. An Adapted Caprini score was devised which included only the clinical criteria. The patients were scored by two persons independently at admission and followed up till the 30th post-operative day and primary and secondary end points were statistically analyzed.

RESULTS

Three hundred and one patients were included and the overall incidence of VTE at 30 days was 7.3%. The risk of developing VTE was found to be significantly higher among the >8 score group as compared to 3-4 group (OR = 153.5, p < 0.001), or the 5-6 group (OR = 52.9, p < 0.001) or the 7-8 group (OR = 2.3, p = 0.002). Patients with a score of 7-8 were more likely to develop VTE as compared to 3-4 group (OR = 67.5, p < 0.001) or the 5-6 group (OR = 23.2, p < 0.001).

CONCLUSION

The risk of developing VTE is less significant in the 5-6 score group compared to 7-8 or more score group. Further stratification of the highest risk groups is recommended to provide appropriate prophylaxis only to the patients with high scores, thereby reducing complications due to VTE prophylaxis.

Risk factors for venous thromboembolism after acute trauma: A population-based case-cohort study

BACKGROUND

Predictors of venous thromboembolism (VTE) after trauma are uncertain.

OBJECTIVE

To identify independent predictors of VTE after acute trauma.

METHODS

Using Rochester Epidemiology Project (REP) resources, we identified all Olmsted County, MN residents with objectively-diagnosed incident VTE within 92days after hospitalization for acute trauma over the 18-year period, 1988-2005. We also identified all Olmsted County residents hospitalized for acute trauma over this time period and chose one to two residents frequency-matched to VTE cases on sex, event year group and ICD-9-CM trauma code predictive of surgery. In a case-cohort study, demographic, baseline and time-dependent characteristics were tested as predictors of VTE after trauma using Cox proportional hazards modeling.

RESULTS

Among 200 incident VTE cases, the median (interquartile range) time from trauma to VTE was 18 (6, 41) days. Of these, 62% cases developed VTE after hospital discharge. In a multiple variable model including 370 cohort members, patient age at injury, male sex, increasing injury severity as reflected by the Trauma Mortality Prediction Model (TMPM) Mortality Score, immobility prior to trauma, soft tissue leg injury, and prior superficial vein thrombosis were independent predictors of VTE (C-statistic=0.78).

CONCLUSIONS

We have identified clinical characteristics which can identify patients at increased risk for VTE after acute trauma, independent of surgery. Almost two thirds of all incident VTE events occurred after initial hospital discharge (18day median time from trauma to VTE) which questions current practice of not extending VTE prophylaxis beyond hospital discharge.

Association between postoperative thromboembolism prophylaxis and complications following urological surgery

Thromboembolism represents the most significant complication and cause of non-surgical mortality in major urological surgery. The aim of the present study was to assess the association between the type of pharmacological thromboembolism prophylaxis and the postoperative complication rate in a cohort of patients undergoing major urological surgery. All consecutive patients treated with major urological surgery between December 2011 and March 2013 were evaluated. For each patient, clinical and demographic data, as well as information on the post-surgical complications and the type of pharmacological thromboembolism prophylaxis, were collected. In total, 453 patients (mean age, 63.36±12.05 years) were recruited (43.5% for prostate surgery, 33.1% for renal surgery, 12.1% for bladder surgery and 11.3% for other surgery). Postoperative blood transfusions were required in 50 cases (11.0%). A total of 32 patients (7.1%) underwent re-intervention due to the occurrence of grade ≥3 complications, with a readmission rate of 2.0%. According to the Clavien-Dindo Classification, the complications were grade 1 in 36.0% of the cases, grade 2 in 19.4%, grade 3 in 6.0%, grade 4 in 2.0% and grade 5 (mortality) in 0.7%. Only 1 case of deep venous thrombosis not associated with pulmonary thromboembolism was observed. Univariate analyses showed a significant negative association (higher risk of complications) between the use of >4,000 IU enoxaparin as the thromboembolism prophylaxis and postoperative blood transfusion rate (P=0.045), re-intervention rate (P=0.001) and the occurrence of grade ≥3 complications (P<0.001). Multivariate analysis confirmed the significant association between the use of >4,000 IU enoxaparin and both re-intervention rate (P=0.013) and occurrence of grade ≥3 complications (P=0.002). High doses of enoxaparin (>4,000 IU) may lead to an increased risk of re-intervention and severe postoperative complications following major urological surgery. Randomised, controlled trials comparing the effect of different types of pharmacological thromboembolism prophylaxis on postoperative complications following major urological surgery are required.

Risk of symptomatic venous thromboembolism following emergency appendicectomy in adults

Background

Appendicectomy is the commonest intra-abdominal emergency surgical procedure, and little is known regarding the magnitude and timing of the risk of venous thromboembolism (VTE) after surgery. This study aimed to determine absolute and relative rates of symptomatic VTE following emergency appendicectomy.

Methods

A cohort study was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data of patients who had undergone emergency appendicectomy from 2001 to 2011. Crude rates and adjusted incidence rate ratios (IRRs) for VTE were calculated using Poisson regression, compared with baseline risk in the year before appendicectomy.

Results

A total of 13 441 patients were identified, of whom 56 (0·4 per cent) had a VTE in the first year after surgery. The absolute rate of VTE was highest during the in-hospital period, with a rate of 91·29 per 1000 person-years, which was greatest in those with a length of stay of 7 days or more (267·12 per 1000 person-years). This risk remained high after discharge, with a 19·1- and 6·6-fold increased risk of VTE in the first and second months respectively after discharge, compared with the year before appendicectomy (adjusted IRR: month 1, 19·09 (95 per cent c.i. 9·56 to 38·12); month 2, 6·56 (2·62 to 16·44)).

Conclusion

The risk of symptomatic VTE following appendicectomy is relatively high during the in-hospital admission and remains increased after discharge. Trials of extended thromboprophylaxis are warranted in patients at particularly high risk.

Microsurgery and the Hypercoagulable State: A Hematologist's Perspective

Hypercoagulability can pose a significant problem in microsurgical reconstruction. Here, the authors provide a comprehensive review of macrovascular and microvascular clotting phenomena from the unique viewpoint of two microsurgeons and a hematologist. The authors review the literature surrounding prevention of microvascular clots and provide an extensive discussion of hereditary thrombophilia. The authors also make explicit recommendations regarding the utility of thrombophilia testing and preoperative and perioperative management strategies for patients with hypercoagulability.

The epidemiology of venous thromboembolism

Venous thromboembolism (VTE) is categorized by the U.S. Surgeon General as a major public health problem. VTE is relatively common and associated with reduced survival and substantial health-care costs, and recurs frequently. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and VTE risk factors, including increasing patient age and obesity, hospitalization for surgery or acute illness, nursing-home confinement, active cancer, trauma or fracture, immobility or leg paresis, superficial vein thrombosis, and, in women, pregnancy and puerperium, oral contraception, and hormone therapy. Although independent VTE risk factors and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be relatively constant, or even increasing.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Risk of Post-Discharge Venous Thromboembolism and Associated Mortality in General Surgery: A Population-Based Cohort Study Using Linked Hospital and Primary Care Data in England

BACKGROUND

Trends towards day case surgery and enhanced recovery mean that postoperative venous thromboembolism (VTE) may increasingly arise after hospital discharge. However, hospital data alone are unable to capture adverse events that occur outside of the hospital setting. The National Institute for Health and Care Excellence has suggested the use of primary care data to quantify hospital care-related VTE. Data in surgical patients using these resources is lacking. The aim of this study was to measure VTE risk and associated mortality in general surgery using linked primary care and hospital databases, to improve our understanding of harm from VTE that arises beyond hospital stay.

METHODS

This was a longitudinal cohort study using nationally linked primary care (Clinical Practice Research Datalink, CPRD), hospital administrative (Hospital Episodes Statistics, HES), population statistics (Office of National Statistics, ONS) and National Cancer Intelligence Network databases. Routinely collected information was used to quantify 90-day in-hospital VTE, 90-day post-discharge VTE and 90-day mortality in adults undergoing one of twelve general surgical procedures between 1st April 1997 and 31st March 2012. The earliest postoperative recording of deep vein thrombosis or pulmonary embolism in CPRD, HES and ONS was counted in each patient. Covariates from multiple datasets were combined to derive detailed prediction models for VTE and mortality. Limitation included the capture of VTE presenting to healthcare only and the lack of information on adherence to pharmacological thromboprophylaxis as there was no data linkage to hospital pharmacy records.

RESULTS

There were 981 VTE events captured within 90 days of surgery in 168005 procedures (23.7/1000 patient-years). Overall, primary care data increased the detection of postoperative VTE by a factor of 1.38 (981/710) when compared with using HES and ONS only. Total VTE rates ranged between 3.2/1000 patient-years in haemorrhoidectomy to 118.3/1000 patient-years in esophagogastric resection. Predictors of VTE included emergency surgery (OR = 1.91 95%CI 1.60-2.28, p<0.001), age (OR = 1.02 95%CI 1.02-1.03, p<0.001), body mass index (OR = 1.03 95%CI 1.01-1.04, p<0.001), previous VTE (OR = 8.07 95%CI 6.61-9.83, p<0.001), length of stay (OR = 1.00 95%CI 1.00-1.00, p = 0.007) and cancer stages II (OR = 1.38 95%CI 1.03-1.87, p = 0.033), III (OR = 1.50 95%CI 1.11-2.01, p = 0.008) and IV (OR = 1.63 95%CI 1.03-2.59, p = 0.038). Major organ resections had the greatest odds of VTE when adjusted for other risk factors including length of hospital stay. Post-discharge VTE accounted for 64.8% (636/981) of all recorded VTE. In-hospital VTE (165.4/1000 patient-years) was recorded more frequently than post-discharge VTE (16.2/1000 patient-years). Both in-hospital (OR = 2.07 95%CI 1.51-2.85, p<0.001) and post-discharge (OR = 4.03 95%CI 2.95-5.51, p<0.001) VTE independently predicted 90-day mortality. In patients who died and VTE was recorded on HES or CPRD (n = 56), VTE was one of the causes of death in 37.5% (21/56) of cases.

CONCLUSIONS

A large proportion of postoperative VTE was detected in primary care. Evaluation of linked databases was a useful way of measuring postoperative VTE at population level. These resources identified a significant association between post-discharge VTE and mortality in general surgery.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

Optimal thromboprophylaxis after cardiac surgery is uncertain. This systematic review aimed to define the incidence and risk factors for deep vein thrombosis (DVT), fatal and nonfatal pulmonary embolism (PE), and assess whether venous thromboembolism (VTE) prophylaxis was effective in reducing VTE without complications after cardiac surgery.

Methods and Results

Two reviewers independently searched and assessed the quality and outcomes of randomized, controlled trials (RCTs) and observational studies on VTE after cardiac surgery in the MEDLINE, EMBASE, and Cochrane controlled trial register (1966 to December 2014). Sixty‐eight studies provided data on VTE outcomes or complications related to thromboprophylaxis after cardiac surgery. The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses. VTE prophylaxis was associated with a reduced risk of PE (relative risk [RR], 0.45; 95% confidence interval [CI], 0.28–0.72; P=0.0008) or symptomatic VTE (RR, 0.44; 95% CI, 0.28–0.71; P=0.0006) compared to the control without significant heterogeneity. Median incidence (interquartile range) of symptomatic DVT, PE, and fatal PE were 3.2% (0.6–8.1), 0.6% (0.3–2.9), and 0.3% (0.08–1.7), respectively. Previous history of VTE, obesity, left or right ventricular failure, and prolonged bed rest, mechanical ventilation, or use of a central venous catheter were common risk factors for VTE. Bleeding or cardiac tamponade requiring reoperation owing to pharmacological VTE prophylaxis alone, without systemic anticoagulation, was not observed.

Conclusions

Unless proven otherwise by adequately powered RCTs, initiating pharmacological VTE prophylaxis as soon as possible after cardiac surgery for patients who have no active bleeding is highly recommended.

Venous thromboembolism and lung cancer: a review

Venous thromboembolism (VTE) is a common complication of malignancies and epidemiological studies suggest that lung cancer belonged to the group of malignancies with the highest incidence rates of VTE. Risk factors for VTE in lung cancer patients are adenocarcinoma, NSCLC in comparison with SCLC, advanced disease, pneumonectomy, chemotherapy including antiangiogenic therapy. Other risk factors are pretreatment platelet counts and increased release of TF-positive microparticles. Elevated D-dimer levels do not necessarily indicate an increased risk of VTE but have been shown to be predictive for a worse clinical outcome in lung cancer patients. Mechanisms responsible for the increase in venous thrombosis in patients with lung cancer are not understood.

Currently no biomarker is recognized as a predictor for VTE in lung cancer patients.

Although several clinical trials have reported the efficacy of antithrombotic prophylaxis in patients with lung cancer who are receiving chemotherapy, further trials are needed to assess the clinical benefit since these patients are at an increased risk of developing a thromboembolism.

Characteristics and Risk Factors of Cancer Associated Venous Thromboembolism

INTRODUCTION

The objective of this study was to examine the differences in commonly associated characteristics and risk factors of venous thromboembolism (VTE) between patients with and without cancer in a VTE population.

MATERIALS AND METHODS

Uniform data were collected for patients with a diagnosis of VTE obtaining care at CDC funded Thrombosis Network Centers. Patient characteristics and risk factors were compared in VTE patients with and without cancer. Logistic regression was used to calculate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) to assess patient characteristics and thrombotic risk factors more frequently identified among VTE patients with cancer compared to those without cancer.

RESULTS

Between August 2003 and April 2011, 3,115 adult patients with a diagnosis of VTE including 189 (6.1%) patients with active cancer participated in the multi-site thrombosis registry. VTE patients with cancer had a higher prevalence of PE and DVT in unusual sites compared to those without cancer. Thrombophilia was more common among VTE patients without cancer than those with cancer (25.1% vs 10.6%, p<0.001). In adjusted analysis, age group≥45years (OR =5.20, 95% CI, 3.30, 8.18), surgery (OR =1.86, 95% CI, 1.19, 2.91), and hypertension (OR =1.66, 95% CI, 1.15, 2.40) were the VTE risk factors more commonly found among VTE patients with cancer.

CONCLUSION

The study identified several thrombotic risk factors more likely to be found with cancer associated VTE, which may help to characterize at risk cancer patients and to develop prevention and management strategies in this population.

Ethnic diversity in the genetics of venous thromboembolism

Genetic susceptibility is considered as a crucial factor for the development of venous thromboembolism (VTE). Epidemiologic and genetic studies have revealed clear disparities in the incidence of VTE and the distribution of genetic factors for VTE in populations stratified by ethnicity worldwide. While gain-of-function polymorphisms in the procoagulant genes are common inherited factors in European-origin populations, the most prevalent molecular basis for venous thrombosis in Asians is confirmed to be dysfunctional variants in the anticoagulant genes. With the breakthrough of genomic technologies, a set of novel common alleles and rare mutations associated with VTE have also been identified, in different ethnic groups. Several putative pathways contributing to the pathogenesis of thrombophilia in populations of African-ancestry are largely unknown, as current knowledge of hereditary and acquired risk factors do not fully explain the highest risk of VTE in Black groups. In-depth studies across diverse ethnic populations are needed to unravel the whole genetics of VTE, which will help developing individual risk prediction models and strategies to minimise VTE in all populations.

Prostate cancer, comorbidity, and the risk of venous thromboembolism: A cohort study of 44,035 Danish prostate cancer patients, 1995-2011

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of cancer. It is unknown whether comorbidity interacts clinically with prostate cancer (PC) to increase the VTE rate beyond that explained by PC and comorbidity alone, for example, by delaying diagnosis or precluding treatment.

METHODS

A nationwide, registry-based cohort study of all 44,035 Danish patients diagnosed with PC from 1995 to 2011 and 213,810 men from the general population matched 5:1 on age, calendar time, and comorbidities. The authors calculated VTE rate ratios and the interaction contrast as a measure on the additive scale of the excess VTE rate explained by synergy between PC and comorbidity.

RESULTS

In total, 849 patients in the PC cohort and 2360 men from the general population had VTE during 5 years of follow-up, and their risk of VTE was 2.2% and 1.3%, respectively. The 1-year VTE standardized rate among PC patients who had high comorbidity levels was 15 per 1000 person-years (PYs) (95% confidence interval, 6.8-24 per 1000 PYs), and 29% of that rate was explained by an interaction between PC and comorbidity. The VTE risk was increased among older patients, those with metastases, those with high Gleason scores, those in the D'Amico high-risk group, and those who underwent surgery.

CONCLUSIONS

PC interacted clinically with high comorbidity levels and increased the VTE rate. Because of the large PC burden, reducing VTEs associated with comorbidities may have an impact on VTE risk and the potential to improve prognosis. Clinical interactions between high levels of comorbidity and PC on the risk of VTE were observed. Almost 30% of all episodes of VTE occurred among patients who had high levels of comorbidity.

Epidemiology of venous thromboembolism

Thrombosis can affect any venous circulation. Venous thromboembolism (VTE) includes deep-vein thrombosis of the leg or pelvis, and its complication, pulmonary embolism. VTE is a fairly common disease, particularly in older age, and is associated with reduced survival, substantial health-care costs, and a high rate of recurrence. VTE is a complex (multifactorial) disease, involving interactions between acquired or inherited predispositions to thrombosis and various risk factors. Major risk factors for incident VTE include hospitalization for surgery or acute illness, active cancer, neurological disease with leg paresis, nursing-home confinement, trauma or fracture, superficial vein thrombosis, and-in women-pregnancy and puerperium, oral contraception, and hormone therapy. Although independent risk factors for incident VTE and predictors of VTE recurrence have been identified, and effective primary and secondary prophylaxis is available, the occurrence of VTE seems to be fairly constant, or even increasing.

Postoperative early thromboembolism as a prognostic indicator in patients with curatively resected pancreatic cancer

BACKGROUND

Information regarding postoperative thromboembolism in curatively resected pancreatic cancer is limited. This study aimed to assess the incidence and significance of postoperative thromboembolism.

METHODS

We retrospectively reviewed the medical records of 121 curatively resected pancreatic cancer patients. Early and late thromboembolisms were defined as events that occurred within 1 year and after 1 year, respectively.

RESULTS

Twenty-two patients (18%) experienced thromboembolism. Seven thromboembolic events occurred within 1 month (7, 6%), and the incidence rate decreased over time. Ten (63%) of the 16 patients with early thromboembolism experienced thromboembolism before or at the same time as recurrence; however, 5 (83%) of the 6 patients with late thromboembolism experienced recurrence before thromboembolism (P = .005). A significant difference in recurrence-free survival (P = .016) and borderline difference in overall survival (P = .050) were observed between patients with early thromboembolism and others.

CONCLUSIONS

Thromboembolic events after curative surgery are prevalent in pancreatic cancer, especially within 1 month. Thromboembolic events within 1 year of surgery should be cautiously monitored.

Total joint arthroplasty in cancer patients

Increasing numbers of total joint arthroplasty (TJA) patients have a history, or an active diagnosis, of cancer. We aimed to evaluate the risk of early postoperative complications in these patients. In our series, a history of malignancy was associated with an elevated risk of ischemic cardiac events and postoperative deep vein thrombosis (DVT), while active malignancy was associated with increased respiratory and renal complications, hematoma/seroma formation and early postoperative mortality. Both groups presented increased rates of overall in-hospital complications. Patients with bone metastasis to the hip demonstrated increased DVT and 90-day mortality rates. Cancer patients have increased morbidity and mortality after TJA and should undergo comprehensive medical optimization and adapted thromboprophylaxis.

Venous thromboembolism prophylaxis in mental healthcare: do the benefits outweigh the risks?

Venous thromboembolism is an important cause of morbidity and mortality. In recent years, growing awareness has led to the development of strategies to prevent venous thromboembolism in individuals admitted to hospital who are deemed to be at high risk. However, there remains a considerable degree of uncertainty over whether these strategies are of overall benefit and there are few published studies on people who are admitted to psychiatric hospitals. In this editorial I review current clinical practice and areas of uncertainty with respect to venous thromboembolism prophylaxis and its implementation in mental healthcare settings.

Incidence and risk factors for symptomatic venous thromboembolism following cholecystectomy

BACKGROUND

The benefit of thromboembolism prophylaxis in cholecystectomy is controversial. This population-based study report on the incidence of and risk factors for symptomatic venous thromboembolism (VTE) after cholecystectomy.

METHOD

All cholecystectomies registered in the Swedish Register of Gallstone Surgery and Endoscopic Retrograde Cholangiopancreatography (GallRiks) between 2006 and 2011 were reviewed. By linking patient data to the Swedish National Patient Register (NPR), the 30-day postoperative incidence of VTE (deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) was identified. Age- and gender-standardized incidence ratio (SIR) for deep venous thrombosis (DVT) and pulmonary embolism (PE) were calculated. Multivariable analysis determined risk factors for VTE by calculating odds ratio (OR).

RESULTS

Altogether 62,488 procedures were registered and postoperative VTE was seen in 154 (0.25%) patients. DVT was seen in 36 (0.06%) patients and PE in 25 (0.04%) patients within 30 days after surgery. The SIR for DVT was 22.2 (95% confidence interval (CI) 13.1-31.3) and for PE 5.6 (95% CI 2.3-8.9). Risk factors for VTE within 30 days after cholecystectomy were age >70 years (odds ratio [OR] = 2.69; 95% confidence interval [CI] 1.68-4.30), open cholecystectomy (OR = 1.95; CI 1.31-2.92), operation time >120 min (OR = 1.66; CI 1.18-2.35), acute cholecystitis (OR = 1.69; CI 1.18-2.42), and previous history of VTE (OR = 50.5; CI 27.3-92.8). Thromboembolism prophylaxis (TP) increased the risk for postoperative bleeding (OR = 1.72; 1.44-2.05).

CONCLUSION

The incidence of VTE after cholecystectomy is low and thromboembolism prophylaxis (TP) increases the risk for postoperative bleeding. Patients with previous VTE events should be given TP when undergoing cholecystectomy.

Impact of thrombophilic genes mutations on thrombosis risk in Egyptian nonmetastatic cancer patients

Venous thromboembolism (VTE) is a common complication in cancer patients. Several genetic risk factors related to thrombophilia are known; however, their contributions to thrombotic tendency in cancer patients have conflicting results. We aimed to determine the prevalence of factor V Leiden (FVL), prothrombin (PTH) G20210A and methylene tetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in Egyptian nonmetastatic cancer patients and their influence on thrombosis risk in those patients. Factor V Leiden, PTH G20210A and MTHFR C677T polymorphisms were detected in 40 cancer patients with VTE (group 1) and 40 cancer patients with no evidence of VTE (group 2) by PCR-based DNA analysis. Factor V and MTHFR mutations were higher in group 1 than in group 2 (factor V heterozygous mutation: 20 vs. 7.5%, homozygous mutation: 10 vs. 2.5%; MTHFR heterozygous mutation: 40 vs. 25%, homozygous mutation 5 vs. 0%, respectively) (P = 0.03). Mortality rate was higher in group 1 (75%) than in group 2 (25%; P < 0.001). No difference was found between those groups regarding PTH mutation (P = 1). Mortality rate was higher in the presence of homozygous and heterozygous factor V mutation (100 and 82%, respectively) compared to the wild type (41%) (P = 0.0006). Having any of the three studied gene mutations worsened the overall survival (P = 0.0003). Cox regression proved that both thrombosis and presence of factor V mutation are independent factors affecting survival in cancer patients (P < 0.001 and P = 0.01, respectively). In conclusion, there is an association between factor V and MTHFR mutations and risk of VTE in Egyptian cancer patients. Thrombosis and presence of factor V mutation are independent factors that influence survival in those patients.

Risk of venous thromboembolism after shoulder arthroplasty in the Medicare population

BACKGROUND

Chemoprophylaxis for venous thromboembolism (VTE) is considered standard of care after lower but not after upper extremity arthroplasty. Medicare claims data were analyzed to determine the national incidence of symptomatic VTE after shoulder arthroplasty during the index surgical admission and after discharge.

METHODS

Incidence of VTE was compared between shoulder arthroplasty and lower extremity arthroplasty, and patient-specific risk factors for pulmonary embolism were determined for shoulder arthroplasty. Finally, the incidence of surgical site bleeding was determined for each type of procedure.

RESULTS

VTE complications occurred in 1.2% of lower extremity and 0.53% of shoulder arthroplasties. Patient factors that were associated with an increased risk of VTE included a principal diagnosis of fracture, history of VTE, cardiac arrhythmia, presence of a metastatic tumor, coagulopathy, congestive heart failure, alcohol abuse, and obesity. Adjusted rates of VTE were generally higher for lower extremity compared with shoulder arthroplasties. Prevalence of readmission for VTE was higher for shoulder hemiarthroplasty than for total shoulder arthroplasty. Wound hematoma rates were similar between shoulder and lower extremity procedures.

CONCLUSIONS

VTE rates after shoulder arthroplasty were generally lower than those after lower extremity arthroplasty. We believe that the risk of bleeding combined with the lower rates of VTE with existing lower rates of chemoprophylaxis does not warrant the routine use of anticoagulation. Use of mechanical prophylaxis combined with aspirin may be sufficient for shoulder arthroplasty patients who are not at increased risk of VTE. Chemoprophylaxis with agents other than aspirin may be warranted in patients with a demonstrated risk of VTE.

Increased anaesthesia duration increases venous thromboembolism risk in plastic surgery: A 6-year analysis of over 19,000 cases using the NSQIP dataset

BACKGROUND

Venous thromboembolism (VTE) is a significant cause of morbidity and mortality, particularly in the postoperative setting. Various risk stratification schema exist in the plastic surgery literature, but do not take into account variations in procedure length. The putative risk of VTE conferred by increased length of time under anaesthesia has never been rigorously explored.

AIM

The goal of this study is to assess this relationship and to benchmark VTE rates in plastic surgery.

METHODS

A large, multi-institutional quality-improvement database was queried for plastic and reconstructive surgery procedures performed under general anaesthesia between 2005-2011. In total, 19,276 cases were abstracted from the database. Z-scores were calculated based on procedure-specific mean surgical durations, to assess each case's length in comparison to the mean for that procedure. A total of 70 patients (0.36%) experienced a post-operative VTE. Patients with and without post-operative VTE were compared with respect to a variety of demographics, comorbidities, and intraoperative characteristics. Potential confounders for VTE were included in a regression model, along with the Z-scores.

RESULTS

VTE occurred in both cosmetic and reconstructive procedures. Longer surgery time, relative to procedural means, was associated with increased VTE rates. Further, regression analysis showed increase in Z-score to be an independent risk factor for post-operative VTE (Odds Ratio of 1.772 per unit, p-value < 0.001). Subgroup analyses corroborated these findings.

CONCLUSIONS

This study validates the long-held view that increased surgical duration confers risk of VTE, as well as benchmarks VTE rates in plastic surgery procedures. While this in itself does not suggest an intervention, surgical time under general anaesthesia would be a useful addition to existing risk models in plastic surgery.

Use of novel oral anticoagulants for the treatment of venous thromboembolism and its considerations in Asian patients

Parenteral anticoagulation followed by warfarin has been conventionally used for the treatment of venous thromboembolism (VTE). However, there are numerous troublesome characteristics of warfarin that prompted the development of novel oral anticoagulants (NOACs) for the treatment of VTE. Asians are reported to be at an increased risk of bleeding with warfarin, and while the reported incidence of VTE in Asians is lower than in Caucasians, the annual rate of VTE in Asia is rising along with the need for better oral anticoagulant options. Recently, several Phase III clinical trials with NOACs for the treatment and prevention of VTE recurrence have been published. For the treatment of VTE, the four NOACs - dabigatran, rivaroxaban, apixaban, and edoxaban - each showed comparable efficacy outcomes while resulting in better safety outcomes when compared with conventional treatment. In these trials, Asian patients had comparable efficacy and safety outcomes as other races, except in the edoxaban trial, in which the Asian subgroup had better safety profiles than other races, although further confirmation is necessary. For secondary prevention, dabigatran was compared with conventional treatment and showed similar efficacy and safety outcomes. When NOACs were compared with placebo for secondary prevention of VTE, they showed superior efficacy and increased bleeding except for apixaban, which showed comparable major bleeding and composite of major and clinically relevant nonmajor bleeding rates as placebo. No significant differences in the outcomes based on race were observed in the Asian subgroups for secondary prevention. Therefore, NOACs can be used with similar efficacy and at least similar or superior safety compared with conventional treatment in the treatment of VTE, and at no increased risk in Asian patients.

Rate of venous thromboembolism among surgical patients in Australian hospitals: a multicentre retrospective cohort study

OBJECTIVES

Despite the burden of venous thromboembolism (VTE) among surgical patients on health systems in Australia, data on VTE incidence and its variation within Australia are lacking. We aim to explore VTE and subsequent mortality rates, trends and variations across Australian acute public hospitals.

SETTING

A large retrospective cohort study using all elective surgical patients in 82 acute public hospitals during 2002-2009 in New South Wales, Australia.

PARTICIPANTS

Patients underwent elective surgery within 2 days of admission, aged between 18 and 90 years, and who were not transferred to another acute care facility; 4 362 624 patients were included.

OUTCOME MEASURES

VTE incidents were identified by secondary diagnostic codes. Poisson mixed models were used to derive adjusted incidence rates and rate ratios (IRR).

RESULTS

2/1000 patients developed postoperative VTE. VTE increased by 30% (IRR=1.30, CI 1.19 to 1.42) over the study period. Differences in the VTE rates, trends between hospital peer groups and between hospitals with the highest and those with the lowest rates were significant (between-hospital variation). Smaller hospitals, accommodated in two peer groups, had the lowest overall VTE rates (IRR=0.56:0.33 to 0.95; IRR=0.37:0.23 to 0.61) and exhibited a greater increase (64% and 237% vs 19%) overtime and greater between-hospital variations compared to larger hospitals (IRR=8.64:6.23 to 11.98; IRR=8.92:5.49 to 14.49 vs IRR=3.70:3.32 to 4.12). Mortality among patients with postoperative VTE was 8% and remained stable overtime. No differences in post-VTE death rates and trends were seen between hospital groups; however, larger hospitals exhibited less between-hospital variations (IRR=1.78:1.30 to 2.44) compared to small hospitals (IRR>23). Hospitals performed differently in prevention versus treatment of postoperative VTE.

CONCLUSIONS

VTE incidence is increasing and there is large variation between-hospital and within-hospital peer groups suggesting a varied compliance with VTE preventative strategies and the potential for targeted interventions and quality improvement opportunities.

Preoperative dosing of low-molecular-weight heparin in hepatopancreatobiliary surgery

BACKGROUND

Venous thromboembolism is a common cause of morbidity. Guidelines recommend perioperative thromboprophylaxis, but clinicians remain cautious of bleeding after major oncologic resections.

METHODS

Retrospective analysis of a single institution's prospective hepatopancreatobiliary database was performed for patients undergoing surgery between January 2010 and February 2013. A total of 223 patients received postoperative thromboprophylaxis and 93 patients were dosed with low-molecular-weight heparin (LMWH) preoperatively.

RESULTS

Two hundred twenty-three patients were analyzed; 50.6% underwent pancreatic and 49.3% underwent liver resection. There were no differences in previous venous thromboembolism (3.8% vs 3.3%; P = .56) or preoperative venous thromboembolism scores (5.74 vs 5.67; P = .82). Estimated blood loss (537 mL vs 592 mL; P = .54), transfusions (25.4% vs 30.4%; P = .25), and complications (52.3% vs 43.5%; P = .12) were equivalent. Incidence of thromboembolic events was lower (6.1% vs 1.1%; P = .05); however, bleeding requiring intervention was increased in the preoperative LMWH group (10.9% vs 3.1%; P = .026).

CONCLUSIONS

Caution must be exercised when using LMWH, as bleeding remains a concern for oncologic hepatopancreatobiliary surgery.

Adherence with postdischarge venous thromboembolism chemoprophylaxis recommendations after colorectal cancer surgery among elderly Medicare beneficiaries

OBJECTIVES

To assess national adherence with extended venous thromboembolism (VTE) chemoprophylaxis guideline recommendations after colorectal cancer surgery.

BACKGROUND

Postoperative VTE remains a major cause of morbidity and mortality after abdominal cancer surgery. On the basis of the results from randomized controlled trials, since 2007, national guidelines have suggested that these patients be discharged on VTE chemoprophylaxis.

METHODS

Medicare beneficiaries undergoing open colorectal cancer resections in 2008-2009 were identified using the Medicare Provider Analysis and Review data and limited to those who were enrolled and used Part D for their postoperative prescriptions. Postdischarge use of low-molecular-weight-heparin and other anticoagulants was assessed.

RESULTS

A total of 5078 patients underwent open colorectal cancer surgery and met the inclusion criteria. Of these, 77% underwent colectomy and 23% underwent proctectomy. A prescription for an anticoagulant was filled immediately after discharge for 77 (1.5%) patients, and a low-molecular-weight-heparin for 60 (1.2%) patients. On multivariable analysis, patients were more likely to receive postdischarge VTE chemoprophylaxis if undergoing rectal cancer surgery [incidence rate ratio (IRR), 1.83; 95% confidence interval, 1.07-3.12; vs colon], if higher educational status (IRR, 2.20; 95% confidence interval, 1.23-3.95; vs low education), or if they had a higher Elixhauser comorbidity index (IRR, 1.13; 95% confidence interval, 1.01-1.25; vs lower index).

CONCLUSIONS

Although VTE remains a major issue after abdominal cancer surgery, only 1.5% of Medicare beneficiaries undergoing colorectal cancer surgery received care consistent with established guidelines for postdischarge VTE chemoprophylaxis. Barriers to adherence must be elucidated to improve the quality of care for abdominal and pelvic cancer surgery patients.

Venous and arterial thrombotic risks with thalidomide: evidence and practical guidance

Oral immunomodulatory drugs (IMiDs), namely thalidomide, lenalidomide and pomalidomide, interfere with several pathways important for disease progression. Today they play a crucial role in the treatment of multiple myeloma patients, and have considerably improved myeloma outcomes. These agents, and thalidomide in particular, are associated with higher rates of thromboembolic events, both venous and arterial. Individual risk factors for thromboembolic events include advanced age, previous history of thromboembolism, an indwelling central venous catheter, comorbid conditions (e.g. infections, diabetes, cardiac disease, obesity), current or recent immobilization, recent surgery and inherited thrombophilic abnormalities. Cancer therapy and cancer itself also increase the risk of thromboembolic events. The aim of this review is to help clinicians to define the risk of thrombotic events in patients treated with thalidomide and thus to provide practical recommendations to manage thromboprophylaxis in these patients.