Perioperative anticoagulation in free microvascular flaps - a comparison of different prophylactic regimes in oncologic reconstructive surgery.

OBJECTIVE: Free tissue transfer has an established place in oncologic head and neck surgery. However, the necessity and specific regimen of perioperative thromboprophylaxis remain controversial. Here, the risk of postoperative hemorrhage contrasts with vascular pedicle thrombosis and graft loss. This work compares three different heparin protocols (A-C) with regard to postoperative complications. PATIENTS AND METHODS: A retrospective analysis of our free flap transplants between 2004 and 2023 was conducted. Inclusion criteria were thromboprophylaxis with (A) 500 IU/h unfractionated heparin (UFH), (B) low-molecular-weight heparin (LMWH) once daily, and (C) LMWH once daily with additional immediate preoperative administration. Primary endpoints were the incidence of postoperative bleeding and hematoma and the appearance of flap thrombosis. RESULTS: We evaluated 355 cases, 87 in group A, 179 in group B, and in group C 89 patients. Overall, postoperative bleeding occurred in 8.7% of patients, and 83% underwent hemostasis under intubation anesthesia, with no significant difference between groups (p = 0.784). Hematoma formation requiring revision was found in 3.7% of patients (p = 0.660). We identified postoperative hematoma as a significant influencing factor for venous pedicle thrombosis (OR 3.602; p = 0.001). Venous and arterial flap thrombosis in the graft vessel showed no difference between the groups (p = 0.745 and p = 0.128). CONCLUSIONS: The three anticoagulation regimens appear to be equivalent therapy for the prevention of thrombosis without significant differences in postoperative bleeding. The use of LMWH with additional preoperative administration can, therefore, be administered in free flap reconstruction.

A Comparison Between Fondaparinux Sodium and Low-Molecular-Weight Heparin in Preventing Patients Undergoing Hip Replacement from Deep Vein Thrombosis.

OBJECTIVES: Total hip arthroplasty (THA) is a highly successful and effective surgery for improving hip functions and relieving pain. However, the lower extremities are prone to deep vein thrombosis (DVT) and swelling after surgery, thereby delaying recovery. In this study, we investigated the preventive effects of fondaparinux sodium (FS) and low-molecular-weight heparin (LMWH) on DVT of the lower extremity after THA. METHODS: Firstly, 60 patients who underwent THA at the First Affiliated Hospital of Wannan Medical College from March 2020 to December 2020 were included. Next, the patients were randomly divided into an LMWH group (n = 30) and an FS group (n = 30). Then, the indexes related to DVT were compared between both groups. RESULTS: Specifically, the differences in baseline data, such as age, gender and body mass index (BMI), between the two groups were not statistically significant. The postoperative weight bearing time of patients in the FS group was much shorter than that in the LMWH group. CONCLUSION: Subcutaneous injection of FS not only exhibits superior effects to LMWH in preventing DVT after THA but also has a correlation with reducing the risk of thrombosis and improving patient symptoms.

[Is monitoring of anti-factor Xa levels required for low molecular weight heparin prophylaxis of venous thromboembolism in critically ill patients?]

The incidence and mortality of venous thromboembolism (VTE) are high in critically ill patients, and there is still a risk of VTE and bleeding after the use of fixed-dose low molecular weight heparin (LMWH) for prophylaxis. The level of anti-factor Xa is not up to standard after LMWH prophylaxis in patients with surgery or trauma. The condition of critically ill patients is complicated, and the proportion of patients with low antithrombin III is high, which can affect the prophylactic efficacy of LMWH and contribute to VTE occurrence. There is currently no consensus on whether adjusting LMWH dose according to anti-factor Xa levels can reduce VTE occurrence in critically ill patients. High-quality multicenter randomized controlled studies are needed in the future to establish new approaches for precise prevention of VTE in critically ill patients.

Perioperative Administration of Tranexamic Acid and Low Molecular Weight Heparin for Enhanced Blood Management in Intertrochanteric Fractures: A Randomized Controlled Study.

BACKGROUND This prospective study from a single center aimed to compare the perioperative blood loss (PBL) in 79 patients with intertrochanteric fractures (IF) treated with intramedullary nailing (IMN) using 3 regimens of combined tranexamic acid (TXA) and low molecular weight heparin (LMWH), proposing a novel therapy of 4-dose TXA. MATERIAL AND METHODS We recruited 79 patients and randomly divided them into 3 groups. The 4-dose TXA group (22 patients) received 1.0 g intravenous TXA 30 min before surgery and 1.0 g at intervals of 3, 6, and 9 h before surgery. The 1-dose TXA group (25 patients) received 1.0 g intravenous TXA 30 min before surgery, while the control group (32 patients) did not receive TXA. LMWH was applied 12 h after surgery in each group. The primary metrics evaluated included hidden blood loss (HBL), total blood loss (TBL), and the number and incidence rate of deep vein thrombosis (DVT). RESULTS Analysis of the HBL revealed that the 4-dose TXA group had the lowest average (583.13±318.08 ml), followed by the 1-dose TXA group (902.94±509.99 ml), and the control group showed the highest (1154.39±452.06 ml) (P<0.05). A similar result was observed for TBL (4-dose group: 640.86±337.22 ml, 1-dose group: 971.74±511.14 ml, control group: 1226.27±458.22 ml, P<0.05). Regarding DVT, the 4-dose TXA group had 5 cases (incidence rate 22.73%), the 1-dose TXA group had 6 cases (incidence rate 24.00%), and the control group had 8 cases (incidence rate 25.00%), with no significant difference among groups (P>0.05). CONCLUSIONS Treatment using 4-dose TXA and LMWH can effectively reduce PBL without increasing the DVT risk in IF patients with IMN.

[Translation into French and republication of: "Management of cancer-associated thromboembolism in vulnerable population"]. / Traduction et republication de : « Prise en charge de la maladie thromboembolique veineuse associée au cancer chez les populations vulnérables ¼.

Although all patients with cancer-associated thrombosis (CAT) have a high morbidity and mortality risk, certain groups of patients are particularly vulnerable. This may expose the patient to an increased risk of thrombotic recurrence or bleeding (or both), as the benefit-risk ratio of anticoagulant treatment may be modified. Treatment thus needs to be chosen with care. Such vulnerable groups include older patients, patients with renal impairment or thrombocytopenia, and underweight and obese patients. However, these patient groups are poorly represented in clinical trials, limiting the available data on which treatment decisions can be based. Meta-analysis of data from randomised clinical trials suggests that the relative treatment effect of direct oral factor Xa inhibitors (DXIs) and low molecular weight heparin (LMWH) with respect to major bleeding could be affected by advanced age. No evidence was obtained for a change in the relative risk-benefit profile of DXIs compared to LMWH in patients with renal impairment or of low body weight. The available, albeit limited, data do not support restricting the use of DXIs in patients with TAC on the basis of renal impairment or low body weight. In older patients, age is not itself a critical factor for choice of treatment, but frailty is such a factor. Patients over 70 years of age with CAT should undergo a systematic frailty evaluation before choosing treatment and modifiable bleeding risk factors should be addressed. In patients with renal impairment, creatine clearance should be assessed and monitored regularly thereafter. In patients with an eGFR less than 30mL/min/1.72m2, the anticoagulant treatment may need to be adapted. Similarly, platelet count should be assessed prior to treatment and monitored regularly. In patients with grade 3-4, thrombocytopenia (less than 50,000platelets/µL) treatment with a LMWH at a reduced dose should be considered. For patients with CAT and low body weight, standard anticoagulant treatment recommendations are appropriate, whereas in obese patients, apixaban may be preferred.

Monitoring anti-Xa levels in elderly medical patients undergoing thromboprophylaxis: A prospective cohort study.

INTRODUCTION: Given the rising incidence of venous thromboembolism (VTE) and insufficient thromboprophylaxis dosing evidence in certain patients, the precise monitoring of anti-Xa (aFXa) levels is crucial. The aim of this study is to investigate the achievement of prophylactic aFXa levels in medical inpatients who were receiving parenteral anticoagulant and to evaluate the impact of various factors on aFXa levels. METHODS: This is a single-center observational cohort study conducted on patients admitted to the Department of Internal Medicine at the University Hospital of Heraklion, Greece, from March to August 2023. These individuals received low-molecular-weight heparins thromboprophylaxis owing to an increased risk of VTE. Data regarding demographics, past medical history, and somatometric and laboratory findings were recorded. The established range for peak prophylactic aFXa levels was defined as 0.2-0.5 IU/mL. RESULTS: In this study, we enrolled 150 individuals [91 (60.7%) women] with a mean age of 80.0 ± 14.1 years. Sixty-two (41.4%) patients exhibited non-prophylactic peak aFXa levels. Supratherapeutic levels were observed in all underweight patients and subtherapeutic levels in 12 of 13 obese patients in class II and III. A multivariate linear regression analysis revealed that body weight, cancer, and the Charlson Comorbidity Index (CCI) were independent factors influencing aFXa levels. CONCLUSIONS: Our study reveals a substantial portion of medical elderly inpatients on thromboprophylaxis with non-prophylactic aFXa levels, with a notable prevalence among underweight and severely obese patients. Body weight, cancer, and CCI were identified as independent factors influencing aFXa levels, advocating for tailored thromboprophylaxis strategies. Further research is warranted to validate personalized dosing approaches and to enhance clinical decision-making. Geriatr Gerontol Int 2024; 24: 587-594.

Combination anticoagulation strategy in pregnancy with mechanical valves: The KYBELE study.

BACKGROUND: Optimal first-trimester anticoagulation is still challenging in pregnant women with mechanical heart valves (MHVs) requiring high-dose warfarin. This multicenter prospective study aims to determine the optimal anticoagulation regimens for pregnant patients with MHVs. METHODS: All women were allocated to one of three treatment options during first trimester including lone low-molecular-weight heparin (LMWH), combination of LMWH + 2.5 mg warfarin, and LMWH+4 mg warfarin. Primary maternal outcome included a combination of death, thromboembolism, severe bleeding, and need for treatment of mechanical valve thrombosis (MVT). Any fetal loss was determined as primary fetal outcome. RESULTS: The study included 78 pregnancies in 65 women with MHVs. Primary maternal outcome rate was 44%, 12.5%, 3.5%, respectively. The rates of primary maternal outcome (44 vs 3.5%, P < .001), obstructive MVT (16 vs 0%, P = .04), MVT requiring treatment (28 vs 0%, P = .003), and cerebral embolism (24 vs 3.4%, P = .041) were found to be significantly higher in lone LMWH group compared to LMWH + 4 mg warfarin group. Moreover, the rates of primary maternal outcome (12.5 vs 44%, P = .015) and treatment for MHV thrombus (4.2 vs 28%, P = .049) were significantly lower in LMWH + 2.5 mg warfarin group compared to lone LMWH group. The incidences of fetal loss were 8 (32%) in the lone LMWH group, 8 (33.3%) in LMWH + 2.5 mg warfarin group, and 11 (37.9%) in LMWH + 4 mg warfarin group (P = .890 for 3-group).Warfarin related-embryopathy was not observed in any case. CONCLUSIONS: The combined anticoagulation strategy of LMWH plus low-dose warfarin during the first trimester of pregnancy may result in less maternal complications with comparable fetal outcomes in patients with MHVs. CONDENSED ABSTRACT: Low-molecular-weight heparin (LMWH) is thought to be safer for the fetus, however it is suspected to be less protective for the mother. To solve this dilemma, the authors suggested a novel anticoagulation strategy in pregnant women with prosthetic valves. Seventy-eight pregnancies of 65 women (median age 32 [27-35] years) were included in the study. A combination of LMWH and a reduced dose warfarin were associated with low rates of thrombus-related complications in pregnant patients with mechanical heart valves.

A systematic review and meta-analysis of the effectiveness of primary thromboprophylaxis in acute lymphoblastic leukemia during early-phase therapy including asparaginase or its prolonged form.

Asparaginase is essential in the initial management of acute lymphoblastic leukemia (ALL) but frequently leads to venous thromboembolism (VTE). Using anticoagulants for primary VTE prevention has been studied with no consensus. We conducted a systematic literature search in PubMed, Scopus, and Web of science and performed random-effect meta-analysis using Mantel-Haenszel method in RevMan 5.4 to analyze primary pharmacological thromboprophylaxis during asparaginase treatment in early-phase (induction, consolidation, or intensification phase) therapy in patients with ALL with all ages and followed with subgroup analysis by age. Meta-analysis of 13 articles describing the effect of antithrombin supplementation in 1375 patients showed that antithrombin prophylaxis decreases the risk of VTE by 43% (RR, 0.57; 95% CI, 0.38 - 0.83; p=0.004), with mild heterogeneity (I2=35%, p=0.10) and moderate certainty by GRADE. 8 articles included for meta-analysis of low-molecular weight heparin (LMWH) treatment in 612 patients showed that it decreased the risk of VTE by nearly 40% (RR, 0.61; 95% CI, 0.45 - 0.81; p=0.00081), with minimal heterogeneity (I2=14%, p=0.31) but low certainty. Subgroup analysis showed that only prophylaxis with antithrombin supplementation significantly decreased the VTE rate in adult patients with moderate certainty. In pediatric patients, one nonrandomized prospective study showed that LMWH combined with antithrombin has a better thromboprophylaxis effect than antithrombin alone. In the PREVAPIX-ALL trial, prophylaxis with direct factor Xa inhibitor Apixaban did not benefit children younger than 18 years except for cases of obesity. We concluded that thromboprophylaxis with antithrombin is effective in ALL patients older than 18 years during the early phase of therapy, and LMWH combined with antithrombin supplementation might be effective for pediatric patients with ALL. Apixaban is effective in pediatric ALL patients with obesity and needs further study in other high-risk patients.

Impact of perioperative low-molecular-weight heparin therapy on clinical events of elderly patients with prior coronary stents implanted > 12 months undergoing non-cardiac surgery: a randomized, placebo-controlled trial.

BACKGROUND: Little is known about the safety and efficacy of discontinuing antiplatelet therapy via LMWH bridging therapy in elderly patients with coronary stents implanted for > 12 months undergoing non-cardiac surgery. This randomized trial was designed to compare the clinical benefits and risks of antiplatelet drug discontinuation via LMWH bridging therapy. METHODS: Patients were randomized 1:1 to receive subcutaneous injections of either dalteparin sodium or placebo. The primary efficacy endpoint was cardiac or cerebrovascular events. The primary safety endpoint was major bleeding. RESULTS: Among 2476 randomized patients, the variables (sex, age, body mass index, comorbidities, medications, and procedural characteristics) and percutaneous coronary intervention information were not significantly different between the bridging and non-bridging groups. During the follow-up period, the rate of the combined endpoint in the bridging group was significantly lower than in the non-bridging group (5.79% vs. 8.42%, p = 0.012). The incidence of myocardial injury in the bridging group was significantly lower than in the non-bridging group (3.14% vs. 5.19%, p = 0.011). Deep vein thrombosis occurred more frequently in the non-bridging group (1.21% vs. 0.4%, p = 0.024), and there was a trend toward a higher rate of pulmonary embolism (0.32% vs. 0.08%, p = 0.177). There was no significant difference between the groups in the rates of acute myocardial infarction (0.81% vs. 1.38%), cardiac death (0.24% vs. 0.41%), stroke (0.16% vs. 0.24%), or major bleeding (1.22% vs. 1.45%). Multivariable analysis showed that LMWH bridging, creatinine clearance < 30 mL/min, preoperative hemoglobin < 10 g/dL, and diabetes mellitus were independent predictors of ischemic events. LMWH bridging and a preoperative platelet count of < 70 × 109/L were independent predictors of minor bleeding events. CONCLUSIONS: This study showed the safety and efficacy of perioperative LMWH bridging therapy in elderly patients with coronary stents implanted > 12 months undergoing non-cardiac surgery. An alternative approach might be the use of bridging therapy with half-dose LMWH. TRIAL REGISTRATION: ISRCTN65203415.

Structured benefit-risk assessment for enoxaparin, in the context of its label extension, for the extended treatment of deep vein thrombosis and pulmonary embolism, and prevention of its recurrence in patients with active cancer.

PURPOSE: Guidelines recommend low-molecular-weight heparins (LMWHs) for patients with cancer-associated thrombosis. However, until recently, only dalteparin and tinzaparin were approved in the European Economic Area (EEA) for these patients. This study compares the benefit-risk profile of enoxaparin with dalteparin and tinzaparin for the extended treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), and prevention of recurrence in adult patients with active cancer. METHODS: A semi-quantitative structured benefit-risk assessment was conducted for the label-extension application of enoxaparin based on the benefit-risk action team descriptive framework: define decision context; determine key benefit and risk outcomes; identify data sources; extract data; interpret results. RESULTS: The key benefits were defined as reduced all-cause mortality and venous thromboembolism (VTE) recurrence (including symptomatic DVT, fatal PE or non-fatal PE); the key risks were major and non-major bleeding of clinical significance, and heparin-induced thrombocytopenia (HIT). Enoxaparin demonstrated comparable effects for the reduction of VTE recurrence and all-cause mortality versus other EEA-approved LMWHs (dalteparin, tinzaparin). There was no evidence of a significant difference between enoxaparin and the comparator groups with regard to incidence of major and non-major bleeding. The data on HIT were too limited to assess the difference between the two groups. CONCLUSIONS: The assessment demonstrated a favourable benefit-risk profile for enoxaparin similar to that of other EEA-approved LMWHs for the treatment of DVT and PE and the prevention of recurrence in patients with active cancer and thus supported the label-extension approval.

Weight-Based Dosing for Low-Molecular-Weight Heparin (Enoxaparin) Administration to Achieve Optimal VTE Prophylaxis in Trauma Patients.

INTRODUCTION: Patients admitted after traumatic injuries are at high risk for developing venous thromboembolism (VTE). Low-molecular-weight heparin (LMWH) is commonly used to prevent VTE in this patient population; however, the optimal dosing strategy has yet to be determined. To address this question, a fixed-dosing strategy of LMWH was compared to a weight-based dosing strategy of LMWH for VTE prophylaxis. METHODS: A retrospective, pre-post implementation cohort study compared a fixed vs a weight-based dosing strategy of LMWH for VTE prophylaxis. Patients admitted to our level 1 trauma center were included if they had an estimated glomerular filtration rate >30 mL/min/1.73 m2, received at least 3 doses of LMWH, and had an appropriately drawn anti-Xa level on their initial dosing regimen. Patients in the pre-cohort received 30 mg LMWH subcutaneously twice daily as the initial dosing regimen. Patients in the post-cohort received .5 mg/kg (max 60 mg) LMWH subcutaneously every 12 h as the initial dosing regimen. A goal anti-Xa of .2-.4 IU/mL was targeted for prophylaxis. RESULTS: There were 817 patients in the fixed-dosing group (FDG) and 874 patients in the weight-based dosing group (WBDG). In the FDG, 42.8% of the patients achieved the goal initial anti-Xa level, with 54.1% and 3.1% reaching sub- and supratherapeutic doses, respectively. In the WBDG, 66.5% of patients reached goal initial anti-Xa levels, with 23.5% and 10.1% at sub- and supratherapeutic levels. The distribution of dose ranges was significantly different between the dosing strategies (P-value <.001). There was no difference in the number of patients who received blood products (39.1% vs 41.7%. P-value = .299). CONCLUSIONS: In our study, weight-based dosing of LMWH yielded a significantly higher proportion of patients who achieved goal prophylactic anti-Xa levels than fixed-dosing of LMWH. Larger-scale studies are needed to assess the risk of VTE events and bleeding with these dosing strategies.

Strategies to reduce rates of severe endothermal heat-induced thrombosis following radiofrequency ablation.

OBJECTIVE: Endothermal heat-induced thrombosis (EHIT) is a potential complication of radiofrequency ablation (RFA). Data on effective prophylaxis of EHIT are limited. In 2018, a high-volume, single institution implemented strategies to decrease the incidence of EHIT, including a single periprocedural prophylactic dose of low-molecular-weight heparin to patients with a great saphenous vein (GSV) diameter of ≥8 mm or saphenofemoral junction (SFJ) diameter of ≥10 mm and limiting treatment to one vein per procedure. The size threshold was derived from existing literature. The study objective was to evaluate the effects of these institutional changes on thrombotic complication rates after RFA. METHODS: A retrospective cohort control study was conducted using the Vascular Quality Initiative database. Data were collected for patients who underwent RFA with a GSV diameter of ≥8 mm or SFJ diameter of ≥10 mm from January 2015 to July 2022. The clinical end points were thrombotic complications (ie, thrombophlebitis, EHIT, deep vein thrombosis) and bleeding complications. Patient demographic and procedural variables were included in the analysis, and significant variables after univariable logistic regression were included in a multivariable logistic regression. RESULTS: After the policy change, the overall vein center EHIT rate decreased from 2.6% to 1.5%, with a trend toward significance (P = .096). The inclusion criterion of a GSV diameter of ≥8 mm or an SFJ diameter of ≥10 mm yielded 845 patients, of whom 298 were treated before the policy change and 547 after. There was a significant reduction in the rate of EHIT classified as class ≥III (2.34 vs 0.366; P = .020) after the institutional changes. Treatment of two or more veins and an increased vein diameter were associated with an increased risk of EHIT (P = .049 and P < .001, respectively). No significant association was found between periprocedural anticoagulation and all-cause thrombotic complications or EHIT (P = .563 and P = .885, respectively). CONCLUSIONS: The institutional policy changes have led to lower rates of EHIT, with a reduction in severe EHIT rates in patients with an ≥8-mm diameter GSV or a ≥10-mm diameter SFJ treated with RFA. Of the changes implemented, restricting treatment to one vein was associated with a reduction in severe EHIT. No association was found with periprocedural low-molecular-weight heparin, although a type 2 error might have occurred. Alternative strategies to prevent thrombotic complications should be explored, such as increasing the dosage and duration of periprocedural anticoagulation, antiplatelet use, and nonpharmacologic strategies.

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.

How can Secondary Thromboprophylaxis in High-Risk Pregnant Patients be Improved?

Low-molecular-weight heparin (LMWH) is suggested for thromboprophylaxis in pregnant women with previous venous thromboembolism (VTE). Anyway, there is only limited amount of studies evaluating the effect of LMWH on hemostatic parameters during pregnancy of patients with previous VTE and the need of secondary thromboprophylaxis. We therefore provide results of prospective and longitudinal assessment of changes in hemostasis in high-risk pregnant women at four times during pregnancy (T1-T4) and one time after the postpartum period (T5) used for individualized modification of thromboprophylaxis. In this study, the results of coagulation factor VIII (FVIII) and protein S (PS) activity, ProC Global ratio and anti-Xa activity were evaluated. Despite the thromboprophylaxis, an increased predisposition to thromboembolic complications was detected (significant increase in FVIII activity and decrease in PS function, ProC Global ratio not normalized even after the postpartum period - p < .0001 between controls and T5 for PS and ProC Global). These results indicate that hemostasis may not be restored even 6 to 8 weeks after delivery and pose the question when is it safe to withdraw the anticoagulant thromboprophylaxis in high-risk patients with prior VTE.

Use of direct oral anticoagulants for postoperative venous thromboembolism prophylaxis after surgery for gynecologic malignancies.

Venous thromboembolism is a preventable cause of postoperative mortality in patients undergoing surgery for malignancy. Current standard of care based on international guideline recommends 28 days of extended thromboprophylaxis after major abdominal and pelvic surgery for malignancies with unfractionated heparin or low molecular weight heparin. Direct oral anticoagulants have been approved for the treatment of venous thromboembolism in the general population. This regimen has a significant advantage over other types of anticoagulation regimens, particularly being administered by non-parenteral routes and without the need for laboratory monitoring. In this review, we evaluate the role of direct anticoagulation and provide an update on completed and ongoing clinical trials.

Dual mechanical and pharmacological thromboprophylaxis decreases risk of pulmonary embolus after laparotomy for gynecologic malignancies.

OBJECTIVES: Patients with gynecologic malignancies have high rates of post-operative venous thromboembolism. Currently, there is no consensus for peri-operative thromboprophylaxis specific to gynecologic oncology. We aimed to compare rates of symptomatic pulmonary embolus within 30 days post-operatively, and to identify risk factors for pulmonary embolus. METHODS: The Division of Gynecologic Oncology at Sunnybrook Health Sciences Centre implemented dual thromboprophylaxis for laparotomies in December 2017. We conducted a prospective study of laparotomies for gynecologic malignancies from December 2017 to October 2018, with comparison to historical cohort from January 2016 to November 2017 using the institutional National Surgical Quality Improvement Program database (NSQIP). Pre-intervention, patients received low molecular weight heparin during admission and extended 28-day prophylaxis was continued at the surgeon's discretion. Post-intervention, all patients received both mechanical thromboprophylaxis with sequential compression devices during admission and 28-day prophylaxis with low molecular weight heparin. RESULTS: There were 371 and 163 laparotomies pre- and post-intervention, respectively. Patient characteristics (age, body mass index, diabetes, smoking, tumor stage), rate of malignant cases, operative blood loss and duration, and length of stay were similar between groups. After implementation, pulmonary emboli rates decreased from 5.1% to 0% (p=0.001). There were more cytoreductive procedures pre-intervention (p≤0.0001) but surgical complexity scores were similar (p=0.82). Univariate analysis revealed that surgery pre-intervention (OR 4.25, 95% CI 1.04 to 17.43, p=0.04), length of stay ≥5 days (OR 11.94, 95% CI 2.65 to 53.92, p=0.002), and operative blood loss ≥500 mL (OR 2.85, 95% CI 1.05 to 7.8, p=0.04) increased risk of pulmonary embolus. On multivariable analysis, surgery pre-intervention remained associated with more pulmonary emboli (OR 4.16, 95% CI 1.03 to 16.79, p=0.045), when adjusting for operative blood loss. CONCLUSION: Dual thromboprophylaxis after laparotomy significantly reduced rates of pulmonary embolus in this high-risk patient population.

Early Chemoprophylaxis Against Venous Thromboembolism in Patients With Traumatic Brain Injury.

INTRODUCTION: Timing to start of chemoprophylaxis for venous thromboembolism (VTE) in patients with traumatic brain injury (TBI) remains controversial. We hypothesize that early administration is not associated with increased intracranial hemorrhage. METHODS: A retrospective study of adult patients with TBI following blunt injury was performed. Patients with penetrating brain injury, any moderate/severe organ injury other than the brain, need for craniotomy/craniectomy, death within 24 hours of admission, or progression of bleed on 6 hour follow-up head computed tomography scan were excluded. Patients were divided into early (≤24 hours) and late (>24 hours) cohorts based on time to initiation of chemoprophylaxis. Progression of bleed was the primary outcome. RESULTS: 264 patients were enrolled, 40% of whom were in the early cohort. The average time to VTE prophylaxis initiation was 17 hours and 47 hours in the early and late groups, respectively (P < .0001). There was no difference in progression of bleed (5.6% vs. 7%, P = .67), craniectomy/-craniotomy rate (1.9% vs. 2.5%, P = .81), or VTE rate (0% vs. 2.5%, P = .1). CONCLUSION: Early chemoprophylaxis is not associated with progression of hemorrhage or need for neurosurgical intervention in patients with TBI and a stable head CT 7 hours following injury.

Evaluating compliance of extended venous thromboembolism prophylaxis following abdominopelvic surgery for cancer: A multidisciplinary quality improvement project.

BACKGROUND AND OBJECTIVES: Despite quality evidence supporting postoperative extended venous thromboembolism prophylaxis (eVTEp) following abdominopelvic cancer surgery, baseline use of eVTEp at our institution was 3%. Our project aim was to improve the proportion of patients prescribed eVTEp following surgery for gynecologic, hepatobiliary, and colorectal cancers by a 30% absolute increase. METHODS: We performed an interrupted time series study using quality improvement methodology. Postoperative order sets, pre-printed prescriptions, process checklists, and multimodal education were introduced. Process and outcome data were collected and analyzed on statistical process control charts. RESULTS: We included 324 patients with gynecologic and hepatobiliary cancers. Despite efforts to include them, the colorectal team did not participate. The monthly mean order set-use was 58% (SD = 14%), by specialty: gynecology 79%, hepatobiliary 47%. The proportion of patients prescribed eVTEp increased from 3% to 70% (SD = 14%). The target goal was surpassed and sustained by both cohorts. Patient compliance was 73% (n = 117/160, SD = 16%). Of those who stopped eVTEp early, 45% (n = 14/31) objected because of the injectable nature. Bleeding events were infrequent (0.6%, n = 2/324). CONCLUSIONS: Three process changes and multimodal education resulted in a significant increase in eVTEp use. Failure to identify improvement champions limited project expansion to colorectal patients. Patient compliance was largely limited by the injectable nature of the medication.

Mechanisms of COVID-19-induced kidney injury and current pharmacotherapies.

The COVID-19 pandemic created a worldwide debilitating health crisis with the entire humanity suffering from the deleterious effects associated with the high infectivity and mortality rates. While significant evidence is currently available online and targets various aspects of the disease, both inflammatory and noninflammatory kidney manifestations secondary to COVID-19 infection are still largely underrepresented. In this review, we summarized current knowledge about COVID-19-related kidney manifestations, their pathologic mechanisms as well as various pharmacotherapies used to treat patients with COVID-19. We also shed light on the effect of these medications on kidney functions that can further enhance renal damage secondary to the illness.

The therapeutic efficacy and safety of traditional Chinese medicine injection combined with low-molecular-weight heparin on the acute lower extremity deep venous thrombosis: A protocol for systematic review and network meta-analysis.

BACKGROUND: Lower extremity deep venous thrombosis (LEDVT) of lower extremities is one of the common clinical diseases. Lack of a timely treatment in the acute stage easily causes pulmonary embolism, thus seriously threatening patients' life. Low-molecular-weight heparin (LMWH), as a new generation of heparin-based anticoagulant and antithrombotic drug, is now commonly used in the clinical treatment of acute lower extremity deep venous thrombosis (ALEDVT). Relevant randomized controlled trials (RCTs) have reported the therapeutic efficacy and safety of Traditional Chinese medicine injection (TCMJ) combined with LMWH on ALDVT, although their conclusions remain controversial. In addition, the efficacy of various TCMJs has rarely been analyzed and compared. This study aims to evaluate the therapeutic efficacy and safety of TCMJ combined with LMWH on ALEDVT through a network meta-analysis. METHODS: RCTs reporting TCMJ combined with LMWH and LMWH along for the treatment of ALEDVT published before November 2021 will be searched in online databases, including the Cochrane Library, Embase, PubMed, Web of Science, Wanfang, Chongqing VIP Chinese Science and Technology Periodical Database, Chinese Biomedical Literature Database, and Chinese National Knowledge Infrastructure. Two investigators will be independently responsible for literature screening, data extraction, and quality evaluation according to Cochrane's risk of bias assessment tool. R software will be used to perform a network Meta-analysis. RESULTS: The results of this meta-analysis will be submitted to a peer-reviewed journal for publication. CONCLUSION: This study will provide high-quality, evidence-based medical evidence for comparing the therapeutic efficacy and safety of TCMJ combined with LMWH and LMWH alone on ALEDVT.