Low molecular weight heparin in prophylaxis of deep vein thrombosis in Asian general surgical patients: A Kashmir experience

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis.

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis. (J Thorac Cardiovasc Surg 2022;▪:1-31).

Benefits and harms of direct oral anticoagulation and low molecular weight heparin for thromboprophylaxis in patients undergoing non-cardiac surgery: systematic review and network meta-analysis of randomised trials

OBJECTIVE

To systematically compare the effect of direct oral anticoagulants and low molecular weight heparin for thromboprophylaxis on the benefits and harms to patients undergoing non-cardiac surgery.

DESIGN

Systematic review and network meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL), up to August 2021.

REVIEW METHODS

Randomised controlled trials in adults undergoing non-cardiac surgery were selected, comparing low molecular weight heparin (prophylactic (low) or higher dose) with direct oral anticoagulants or with no active treatment. Main outcomes were symptomatic venous thromboembolism, symptomatic pulmonary embolism, and major bleeding. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for network meta-analyses. Abstracts and full texts were screened independently in duplicate. Data were abstracted on study participants, interventions, and outcomes, and risk of bias was assessed independently in duplicate. Frequentist network meta-analysis with multivariate random effects models provided odds ratios with 95% confidence intervals, and GRADE (grading of recommendations, assessment, development, and evaluation) assessments indicated the certainty of the evidence.

RESULTS

68 randomised controlled trials were included (51 orthopaedic, 10 general, four gynaecological, two thoracic, and one urological surgery), involving 45 445 patients. Low dose (odds ratio 0.33, 95% confidence interval 0.16 to 0.67) and high dose (0.19, 0.07 to 0.54) low molecular weight heparin, and direct oral anticoagulants (0.17, 0.07 to 0.41) reduced symptomatic venous thromboembolism compared with no active treatment, with absolute risk differences of 1-100 per 1000 patients, depending on baseline risks (certainty of evidence, moderate to high). None of the active agents reduced symptomatic pulmonary embolism (certainty of evidence, low to moderate). Direct oral anticoagulants and low molecular weight heparin were associated with a 2-3-fold increase in the odds of major bleeding compared with no active treatment (certainty of evidence, moderate to high), with absolute risk differences as high as 50 per 1000 in patients at high risk. Compared with low dose low molecular weight heparin, high dose low molecular weight heparin did not reduce symptomatic venous thromboembolism (0.57, 0.26 to 1.27) but increased major bleeding (1.87, 1.06 to 3.31); direct oral anticoagulants reduced symptomatic venous thromboembolism (0.53, 0.32 to 0.89) and did not increase major bleeding (1.23, 0.89 to 1.69).

CONCLUSIONS

Direct oral anticoagulants and low molecular weight heparin reduced venous thromboembolism compared with no active treatment but probably increased major bleeding to a similar extent. Direct oral anticoagulants probably prevent symptomatic venous thromboembolism to a greater extent than prophylactic low molecular weight heparin.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018106181.

Different doses of enoxaparin in the prevention of postoperative abdominal adhesions. Experimental study

Background

Postoperative abdominal adhesions (PAAs) are present in more than 90% of patients undergoing abdominal surgery. They are a cause of chronic pain, hospitalizations, multiple surgeries, and infertility in women of reproductive age. The participation of three processes have been recognized: coagulation, fibrinolysis, and inflammation. The usefulness of subcutaneous enoxaparin in their prevention has been established. The objective is to establish the safest and most efficient dose for PAA prevention by testing five different doses of subcutaneous enoxaparin (0.25, 0.5, 1, 1.5, and 2 mg/kg/day) given in one dose/day for seven days.

Material and methods

Fifty Sprague-Dawley rats were studied, 10 in each group. Adhesions were induced through controlled rubbing of the cecum and suturing of an incision in the terminal ileum. Two independent observers recorded the degree of adhesion formation at 14 days and histologically studied the adhesions.

Statistical analysis

ANOVA compared group averages. The nonparametric Kruskal-Wallis test was used to identify group differences.

Results

The 0.5 mg/kg/day group had greater formation of adhesions (p < 0.001). There was no significant difference between the 1.5 and 2 mg/kg/day groups, though the latter group had an incidence of 27.2% of bleeding in the abdominal cavity. The degree of adhesions in the histological sections coincided with the macroscopic findings. The interobserver agreement was kappa = 0.88 (very good).

Conclusion

The safe and effective dose of subcutaneous enoxaparin to prevent PAA formation was 0.5–1.5 mg/kg/day for seven days.

•

Postoperative abdominal adhesions are the cause of clinical alterations that require significant economic expenses.

•

Activation of the coagulation cascade is a component in the formation of adhesions.

•

Enoxaparin reduces the appearance of postoperative abdominal adhesions.

•

The prophylactic dose of enoxaparin is sufficient to prevent adhesions.

Risk Factors and Clinical Significance of D-Dimer in the Development of Postoperative Venous Thrombosis in Patients with Lung Tumor

BACKGROUND

The incidence of venous thromboembolism (VTE) is higher in patients with lung cancer. The aim of this study was to investigate the risk factors associated with postoperative VTE and explore the VTE predication capacity of D-dimer kinetics.

PATIENTS AND METHODS

Six hundred patients who had lung tumor surgery were analyzed retrospectively between January 2018 and August 2019, and venous ultrasound imaging and D-dimer examination before and after surgery were recommended to all operative patients. Of these 600 patients, 523 patients had venous thromboembolism after surgery, and 77 patients had not found. The general clinical data, postoperative prophylactic anticoagulant therapy, early systemic thromboprophylaxis, 50% increment of D-dimer, 100% increment of D-dimer, and perioperative (preoperative and days 1, 3, and 5 after surgery) D-dimer levels were collected. Logistic regression analysis was used to analyze the independent risk factors of postoperative VTE.

RESULTS

VTE developed in 77 (12.8%) patients. In a univariate analysis, age, surgical approach, tumor size, histology, postoperative preventive anticoagulation, postoperative limb compression therapy, postoperative hemostasis, duration of operation, early systemic thromboprophylaxis, 100% increment of D-dimer, preoperative and postoperative D-dimer level, intraoperative blood loss, and time spent in the hospital were significantly different between the thrombus group and nonthrombus group (P < 0.05). Multivariate analysis showed that age >60 years (P = 0.006) and D-dimer level on 5 days after surgery (P = 0.000) were significant independent risk factors for VTE. Postoperative D-dimer was significantly higher than the preoperative level (P < 0.001). Postoperative D-dimer level was significantly different between benign and malignant tumor groups (P < 0.05) and between the thrombus group and nonthrombus group (P < 0.001). Preventive anticoagulation and limb compression therapy starting from the first day after surgery was statistically significant between the thrombus group and the nonthrombus group (P < 0.05).

CONCLUSION

Continuous detection of D-dimer level after pulmonary tumor surgery combined with thrombotic-related risk factors can better evaluate the occurrence of VTE. Preventive anticoagulant therapy and limb compression therapy starting from the first day after surgery can effectively reduce the incidence of VTE.

Incidence of venous thromboembolism and its pharmacological prophylaxis in Asian general surgery patients: a systematic review

BACKGROUND

Venous thromboembolism (VTE) is a condition that has always been perceived to be rare in Asia. The aim of this systematic review was to gather the current available evidence on the incidence of VTE in this population. A secondary aim was to assess the efficacy of pharmacological prophylaxis, and hence determine its role, in the Asian population.

METHODS

A comprehensive literature search was performed using MEDLINE, Embase, and the Cochrane Database of Systematic Reviews in June 2014. Articles found using search terms related to venous thromboembolism (VTE), Asian countries and general surgery procedures and pathologies were screened using the following inclusion criteria: (1) either the population studied was primarily Asian or the study was conducted in an Asian country, (2) the subjects studied underwent a major gastrointestinal or other general surgery procedure, (3) the primary outcome was the incidence of deep vein thrombosis (DVT) or pulmonary embolus (PE), and (4) secondary outcomes assessed included mortality and complications due to the VTE or prophylaxis against VTE.

RESULTS

Fourteen publications with a total of 11,218 patients were analyzed. Nine of the fourteen were observational studies, with half being prospective in nature. There were five interventional studies of which two were randomized controlled trials. Among the observational studies, the median (range) incidence of above-knee DVT was 0.08 % (0-2.9 %), while the median (range) incidence of PE was 0.18 % (0-0.58 %). The rates of DVT in the control groups were reported to be between 0 and 7.4 %, while the incidence of PE in the control groups ranged from 0 to 1.9 %. Analysis of the comparative studies revealed that the incidence of bleeding-related complications varied from 0 to 18.1 % in the low-molecular-weight heparin (LMWH) group compared to 0-7.5 % in the control group. The difference in minor bleeding complications between the LMWH group and the control group was found to be statistically significant.

CONCLUSION

Data from this systematic review suggest that the risk of VTE in Asian general surgery patients is low, even in the context of risk factors typically regarded as high risk.