Meta-analysis of low molecular weight heparin in the prevention of venous thromboembolism in general surgery

Is Preoperative Chemoprophylaxis Safe for Venous Thromboembolism Prevention in Patients With Head and Neck Cancer?

OBJECTIVE

To assess the safety of preoperative chemoprophylaxis (PEC) in head and neck cancer (HNC) patients undergoing oncologic procedures.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary academic center.

METHODS

HNC patients with Caprini risk score (CRS) ≥5 who underwent inpatient surgery ≥3 hours between 2015 and 2020 were included. Patients were divided into 2 cohorts, PEC and control, based on whether or not they received a single dose of low molecular weight heparin or unfractionated heparin prior to surgery. The primary endpoint was the 30-day rate of major bleeding events.

RESULTS

A total of 539 patients were included; 427 patients received PEC prior to surgery. The rate of major bleeding was 6.7%. The PEC cohort was more likely to have received concurrent aspirin or ketorolac (225 of 427 patients vs 36 of 112 patients; P = .0002), greater duration of chemoprophylaxis (7.8 vs 5.0 days; P < .0001), have higher CRS (7.2 vs 6.6; P < .0001), longer operative times (596 vs 512 minutes; P < .0001), higher blood loss (265 vs 214 ml; P = .02), and higher bleeding rates when compared to the control (34 of 427 patients; P = .03). On multivariate analysis, only PEC was associated with bleeding (odds ratio, 8.74; 95% confidence interval, 1.15-66.5). The rate of VTE was 1.3% and was not significantly different between cohorts.

CONCLUSION

PEC was associated with an increase in bleeding and did not result in lower rates of VTE in patients with HNC. This study highlights the need to determine the optimal regimen of chemoprophylaxis in this patient cohort.

LEVEL OF EVIDENCE: 3

Preferences of pregnant women for postpartum thromboprophylaxis: the bicentric PREFER-PostPartum study

BACKGROUND

Clinical guidelines for postpartum thromboprophylaxis differ due to its uncertain effect and varying preferences of experts. Women's preferences for postpartum thromboprophylaxis are unknown, although they may inform practices and future research.

OBJECTIVES

Our aim was to elicit the pregnant women's preferences for postpartum thromboprophylaxis according to different risks of venous thromboembolism (VTE) and bleeding.

METHODS

In 2 Swiss and French maternity hospitals, we conducted structured interviews of pregnant or postpartum women. Participants were instructed on pulmonary embolism, deep vein thrombosis, postpartum hemorrhage, and subcutaneous injections of low-molecular-weight heparin (LMWH). First, we randomized women to either standard gamble or time trade-off (2 different validated methods) to estimate the utilities (quality of life, from 0 to 1) of these health states. Second, we elicited the preference for the use of short-term postpartum thromboprophylaxis with LMWH vs none across different risks of postpartum VTE and bleeding through direct-choice exercises.

RESULTS

Among 122 participants, median (IQR) health state utilities were 0.725 (0.30-0.925) for pulmonary embolism, 0.75 (0.40-0.97) for postpartum hemorrhage, 0.85 (0.60-0.97) for deep vein thrombosis, and 0.96 (0.96-0.999) for LMWH injections. The median risk of postpartum VTE for preference of the use of postpartum thromboprophylaxis over no treatment was 0.1% (IQR, 0.01%-0.50%) without LMWH-associated bleeding risk and 0.2% (IQR, 0.1%-5%) with a 1% bleeding risk.

CONCLUSION

European pregnant women appear to have a high willingness for 10-day postpartum thromboprophylaxis, preferred over no treatment even for low risks of postpartum VTE. This perspective from patients supports the urgent need for a randomized trial evaluating the efficacy and safety of postpartum thromboprophylaxis.

Sustained success of a Caprini postoperative venous thromboembolism prevention protocol over one decade

BACKGROUND

The objective of this study was to review the long-term efficacy of a post-operative venous thromboembolism (VTE) prevention program at our institution.

METHODS

We performed a review of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) data at our hospital from January 2008-December 2022. The primary outcome was risk-adjusted VTE events.

RESULTS

In 2009, a postoperative general surgery patient was three times more likely to have a postoperative VTE event than predicted (O/E ratio 3.02, 95% CI 1.99-4.40). After implementing a mandatory VTE risk assessment model and a risk-commensurate prophylaxis protocol in the electronic medical record in 2011, the odds ratio of a patient developing a postoperative VTE declined to 0.70 by 2014 (95% CI 0.40-1.23). This success persisted through 2022.

CONCLUSIONS

Since the implementation of a standardized postoperative VTE prevention program in 2011, our institution has sustained a desirably low likelihood of VTE events in general surgery patients.

Venous thromboembolism among Asian populations with localized colorectal cancer undergoing curative resection: is pharmacological thromboprophylaxis required? A systematic review and meta-analysis

PURPOSE

We compared the incidence of venous thromboembolism (VTE) among Asian populations with localized colorectal cancer undergoing curative resection with and without the use of pharmacological thromboprophylaxis (PTP).

METHODS

A comprehensive literature search was undertaken to identify relevant studies published from January 1, 1980 to February 28, 2022. The inclusion criteria were patients who underwent primary tumor resection for localized nonmetastatic colorectal cancer; an Asian population or studies conducted in an Asian country; randomized controlled trials, case-control studies, or cohort studies; and the incidence of symptomatic VTE, deep vein thrombosis, and/or pulmonary embolism as the primary study outcomes. Data were pooled using a random-effects model. This study was registered in PROSPERO on October 11, 2020 (No. CRD42020206793).

RESULTS

Seven studies (2 randomized controlled trials and 5 observational cohort studies) were included, encompassing 5,302 patients. The overall incidence of VTE was 1.4%. The use of PTP did not significantly reduce overall VTE incidence: 1.1% (95% confidence interval [CI], 0%-3.1%) versus 1.9% (95% CI, 0.3%-4.4%; P = 0.55). Similarly, PTP was not associated with significantly lower rates of symptomatic VTE, proximal deep vein thrombosis, or pulmonary embolism.

CONCLUSION

The benefit of PTP in reducing VTE incidence among Asian patients undergoing curative resection for localized colorectal cancer has not been clearly established. The decision to administer PTP should be evaluated on a case-bycase basis and with consideration of associated bleeding risks.

Primary prevention of venous thromboembolism with low molecular weight heparins in surgical patients – 2024: Council of Experts resolution

On March 15, 2024, in Moscow, the Russian Phlebological Association and the National Association of Specialists in Thrombosis, Clinical Hemostasiology and Hemorheology organized a meeting of the Council of Experts during the Russian Forum on Thrombosis and Hemostasis on the acute issues of venous thromboembolism (VTE) primary prevention using low molecular weight heparins (LMWH) in surgical patients with different body weight. The participants reviewed the relevance and prevalence of this problem in surgical practice, discussed risk factors and the frequency of VTE development, including bleeding in the postoperative period, and the Caprini risk score for complications. The discussion also focused on standard and personalized LMWH doses for primary prophylaxis of VTE in the perioperative period in surgical patients, depending on body weight, and the role of laboratory tests, including assessment of LMWH anti-Xa activity for monitoring the efficacy and safety of VTE primary prevention in clinical practice.

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis

Background

Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs.

Objectives

We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research.

Design

We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines.

Setting

NHS hospitals, with primary data collection at four sites.

Participants

Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions.

Interventions

Prophylaxis for all patients, none and according to selected risk assessment models.

Main outcome measures

Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models.

Results

We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%.

Limitations

Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias.

Conclusions

Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research.

Future work

Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation.

Study registration

This study is registered as PROSPERO CRD42020165778 and Researchregistry5216.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

Deep Vein Thrombosis Prophylaxis in Orthopedic Surgery

Deep vein thrombosis (DVT) is a complex and multifactorial process arising from a variety of factors, including recent surgical procedures, traumatic events, and periods of prolonged immobility. The extended period of stasis post-orthopedic surgery places patients at a notably high risk of developing DVT, and DVT-related pulmonary embolism (PE) ranks as the third most common cause of death in orthopedic surgery patients. This review examines the multifaceted risk factors contributing to the development of DVT in orthopedic patients. Additionally, it addresses the importance of DVT prophylaxis in orthopedic settings, the efficacy and safety of various prophylactic methods encompassing both mechanical and pharmacological approaches, and the economic dimensions of DVT prophylaxis, including scrutiny of cost-effectiveness and the exploration of strategies for optimization.

Efficacy and Safety of Anti-Xa-Guided Versus Fixed Dosing of Low Molecular Weight Heparin for Prevention of Venous Thromboembolism in Trauma Patients: A Systematic Review and Meta-Analysis

PURPOSE

Trauma patients are at high risk of venous thromboembolism (VTE). We summarize the comparative efficacy and safety of anti-Xa-guided versus fixed dosing for low molecular weight heparin (LMWH) for the prevention of VTE in adult trauma patients.

METHODS

We searched Medline and Embase from inception through June 1, 2022. We included randomized controlled trials or observational studies comparing anti-Xa-guided versus fixed dosing of LMWH for thromboprophylaxis in adult trauma patients. We incorporated primary data from 2 large observational cohorts. We pooled effect estimates using a random-effects model. We assessed risk of bias using the ROBINS-I tool for observational studies and assessed certainty of findings using GRADE methodology.

RESULTS

We included 15 observational studies involving 10,348 patients. No randomized controlled trials were identified. determined that, compared to fixed LMWH dosing, anti-Xa-guided dosing may reduce deep vein thrombosis [adjusted odds ratio (aOR); 0.52, 95% CI: 0.40-0.69], pulmonary embolism (aOR: 0.48, 95% CI: 0.30-0.78) or any VTE (aOR: 0.54, 95% CI: 0.42-0.69), though all estimates are based on low certainty evidence. There was an uncertain effect on mortality (aOR: 1.06, 95% CI: 0.85-1.32) and bleeding events (aOR: 0.84, 95% CI: 0.50-1.39), limited by serious imprecision. We used several sensitivity and subgroup analyses to confirm the validity of our assumptions.

CONCLUSION

Anti-Xa-guided dosing may be more effective than fixed dosing for prevention of deep vein thrombosis, pulmonary embolism, and VTE for adult trauma patients. These promising findings justify the need for a high-quality randomized study with the potential to deliver practice changing results.

Predictive factors on postoperative venous thromboembolism after minimally invasive colorectal cancer surgery: a retrospective observational study

BACKGROUND

Venous thromboembolism (VTE) is a serious and preventable postoperative complication. However, the predictive significance of perioperative biochemical parameters for VTE after minimally invasive colorectal cancer surgery remains unclear.

METHODS

A total of 149 patients undergoing minimally invasive colorectal cancer surgery were collected between October 2021 and October 2022. Biochemical parameters related to preoperative and postoperative day 1, day 3, and day 5 were collected, including D-Dimer, mean platelet volume (MPV), and maximum amplitude (MA) of thromboelastography (TEG). Receiver operating characteristic (ROC) curves were used to explore the predictive powers of meaningful biochemical parameters for postoperative VTE, and calibration curves were used to assess predictive accuracy.

RESULTS

The overall cumulative incidence of VTE was 8.1% (12/149). The preoperative and postoperative day 3 D-Dimer, postoperative day 3, and day 5 MPV, and postoperative day 1, day 3, and day 5 TEG-MA was significantly higher in the VTE group than in the non-VTE group (P < 0.05). The results of both the ROC curve and the calibration curve indicated that these meaningful D-Dimer, MPV, and TEG-MA had moderate discrimination and consistency for postoperative VTE.

CONCLUSIONS

D-Dimer, MPV, and TEG-MA may predict postoperative VTE in patients undergoing minimally invasive surgery for colorectal cancer at specific times in the perioperative period.

Optimal Timing of Perioperative Chemoprophylaxis in Patients With High Thromboembolic Risk Undergoing Major Abdominal Surgery: A Multicenter Cohort Study

OBJECTIVE

To determine whether early (before skin closure) versus postoperative chemoprophylaxis affects the incidence of venous thromboembolism (VTE) and bleeding following major abdominal surgery, in a high thromboembolic risk population.

BACKGROUND

Major abdominal surgery incurs both VTE and bleeding risks. Patients with high preoperative VTE risk derive the most benefit from chemoprophylaxis, but carry an increased risk of bleeding. The optimal window for chemoprophylaxis in the perioperative period, whereby both VTE and bleeding risks are minimized, is unknown.

METHODS

Analysis of pooled data from 5 multicenter studies including only high thromboembolic risk (Caprini score >4) patients. Clinical VTE was defined as radiographically proven symptomatic disease <30 days postsurgery. Major bleeding was defined as the need for blood transfusion, reintervention, or >20 g/L fall in hemoglobin.

RESULTS

From 5501 cases, chemoprophylaxis was initiated early in 1752 (31.8%) patients and postoperatively in 3749 (68.2%) patients. Baseline characteristics were similar between study groups. The incidence of clinical VTE was not associated with chemoprophylaxis timing [early 0.7% vs. postop 0.7%, odds ratio (OR): 1.11, 95% confidence interval (CI): 0.60-2.15, P =0.730]. Contrastingly, compared with postoperative chemoprophylaxis, early usage increased the risk of all bleeding (5.1% vs. 2.6%, OR: 2.04, 95% CI: 1.52-2.73, P <0.001) major bleeding (3.6% vs. 1.8%, OR: 1.99, 95% CI: 1.40-2.81, P <0.001), and reintervention (2.0% vs. 1.0%, OR: 2.10, 95% CI: 1.32-3.35, P =0.003). Early chemoprophylaxis independently predicted postoperative bleeding (OR: 1.71, 95% CI: 1.25-2.34, P <0.001), but not VTE.

CONCLUSIONS

In high VTE risk patients undergoing major abdominal surgery, chemoprophylaxis commenced postoperatively reduces bleeding risk without affecting clinical VTE risk.

Post-hepatectomy venous thromboembolism: a systematic review with meta-analysis exploring the role of pharmacological thromboprophylaxis

PURPOSE

Patients undergoing hepatectomy are at moderate-to-high risk of venous thromboembolism (VTE). This study critically examines the efficacy of combining pharmacological (PTP) and mechanical thromboprophylaxis (MTP) versus only MTP in reducing VTE events against the risk of hemorrhagic complications.

METHODS

A systematic review of major reference databases was undertaken, and a meta-analysis was performed using common-effects model. Risk of bias assessment was performed using Newcastle-Ottawa scale. Trial sequential analysis (TSA) was used to assess the precision and conclusiveness of the results.

RESULTS

8 studies (n = 4238 patients) meeting inclusion criteria were included in the analysis. Use of PTP + MTP was found to be associated with significantly lower VTE rates compared to only MTP (2.5% vs 5.3%; pooled RR 0.50, p = 0.03, I² = 46%) with minimal type I error. PTP + MTP was not associated with an increased risk of hemorrhagic complications (3.04% vs 1.9%; pooled RR 1.54, p = 0.11, I² = 0%) and had no significant impact on post-operative length of stay (12.1 vs 10.8 days; pooled MD - 0.66, p = 0.98, I² = 0%) and mortality (2.9% vs 3.7%; pooled RR 0.73, p = 0.33, I² = 0%).

CONCLUSION

Despite differences in the baseline patient characteristics, extent of hepatectomy, PTP regimens, and heterogeneity in the pooled analysis, the current study supports the use of PTP in post-hepatectomy patients (grade of recommendation: strong) as the combination of PTP + MTP is associated with a significantly lower incidence of VTE (level of evidence, moderate), without an increased risk of post-hepatectomy hemorrhage (level of evidence, low).

Clinical use of low-dose parenteral anticoagulation, incidence of major bleeding and mortality: a multi-centre cohort study using the French national health data system

PURPOSE

Low-dose parenteral anticoagulation has demonstrated its efficacy for venous thromboembolism prophylaxis in randomized trials. However, current practice is not widely documented. In ambulatory settings, we aimed to provide an overview of the clinical use of low-dose parenteral anticoagulation in France and to assess the incidence of major bleeding and death rates.

METHODS

A population-based prospective cohort study using the French national health data system (SNIIRAM) identified 142,815 adults living in five well-defined geographical areas who had a course of low-dose parenteral anticoagulants (a total of 150,389 courses) in the period 2013-2015. The main outcome measures were the types of low-dose parenteral anticoagulant, the duration and the clinical context. Adjusted incidence rate ratios (IRR) were derived from Poisson models.

RESULTS

Enoxaparin was the most frequently prescribed anticoagulant (58.9%) followed by tinzaparin (27.3%) and fondaparinux (10.9%). Patients receiving unfractionated heparin (N = 766, 0.53%) were older, more frequently had renal disease (48.75%) and had a higher modified HAS-B(L)ED score (≥ 3 in 61.6%) than patients receiving low-molecular weight heparin (LMWH). Surgical thrombo-prophylaxis was the most frequent indication (47.6%), followed by medical prophylaxis (29.9%). Course durations were in line with regulatory agency specifications. Only 43 (0.028%) major bleeding events and 478 (0.32%) deaths were observed. Adjusted IRRs for major bleeding or death were not significantly different for dalteparin/nadroparin, tinzaparin or fondaparinux compared to enoxaparin.

CONCLUSION

Very low incidence rates of major bleeding and all-cause mortality were observed. Our study confirms the safety of LMWHs and fondaparinux in thrombo-prophylaxis in ambulatory settings.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02886533.

Electronic Health Record Risk-Stratification Tool Reduces Venous Thromboembolism Events in Surgical Patients

Background

Venous thromboembolism is a preventable cause of morbidity and mortality after surgery. To ensure that patients receive appropriate venous thromboembolism chemoprophylaxis, a nonmandatory risk-stratification tool based on patient clinical condition was implemented through the electronic health record to stratify patient risk and recommend chemoprophylaxis. We hypothesized that implementing this tool would reduce postoperative venous thromboembolism events in general surgery as well as across all surgical services.

Methods

All adult patients undergoing inpatient surgical operations (January 2012–December 2019) at a single quaternary care center and Level 1 trauma center were abstracted from institutional electronic health record database and stratified into patients admitted before and after venous thromboembolism risk-stratification tool implementation. Bivariable analyses compared venous thromboembolism chemoprophylaxis prescription and venous thromboembolism events with implementation and screening among all surgical patients as well as in general surgery patient subset.

Results

A total of 64,377 adults underwent operations: 27,819 preimplementation and 36,558 postimplementation. A significant reduction in venous thromboembolism events occurred from pre- to post-tool implementation for all cases (0.77% vs 0.47%, P < .001). General surgery patients (n = 15,723) had a significant increase in chemoprophylaxis prescription (81.9% vs 86.0%, P < .001) and a significant reduction in venous thromboembolism events (1.41% vs 0.59%, P < .001). After tool implementation, use of extended postdischarge chemoprophylaxis was greater among general surgery patient subset than the entire patient cohort (46.7% vs 29.6%, P < .001).

Conclusion

The integration of a nonmandatory electronic health record risk-stratification tool was associated with a significant reduction in venous thromboembolism events. Extended chemoprophylaxis was prescribed in nearly half of general surgery patients at very high risk for postdischarge events.

•

Implementing an electronic VTE risk-stratification tool reduced surgical VTE events.

•

Even as a nonmandatory tool, risk stratification led to overall fewer VTE events.

•

Postoperative VTE events were reduced by 39% after the tool was integrated in EHR.

•

With the tool, general surgery had 58% less VTE events and improved prophylaxis use.

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.

A Real-World Comparative Effectiveness Analysis of Thromboprophylactic Use of Enoxaparin Versus Unfractionated Heparin in Abdominal Surgery Patients in a Large U.S. Hospital Database

Introduction: Little is known about outcomes associated with enoxaparin versus unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in abdominal surgery patients in U.S. clinical practice. The purpose of this study was to compare VTE, all-cause mortality, PE-related in-hospital mortality, and hospital costs during abdominal surgery hospitalization and the 90 days post-discharge between patients who received enoxaparin versus UFH prophylaxis. Materials and Methods: Using the Premier Healthcare Database, abdominal surgery patients who received at least 1 day of VTE prophylaxis with enoxaparin or UFH were identified between January 1, 2010 and September 30, 2016. Clinical outcomes were assessed using multivariable logistic regression models and cost outcomes were assessed using generalized linear models. Results: Of 363,669 patients identified, 59% received enoxaparin and 41% UFH. In adjusted analyses, there were statistically significant lower odds of VTE (OR 0.80; 95% CI 0.65-0.97), all-cause mortality (OR 0.67; 95% CI 0.60-0.75), and major bleeding (OR 0.88; 95% CI 0.82-0.94) during the hospitalization for enoxaparin versus UFH, but no differences during the 90-days post-discharge or for PE-related mortality. There was a statistically significant lower total hospital cost with enoxaparin versus UFH during index hospitalization ($8,913 vs $9,017, P < .0001), but not post-discharge ($3,342 vs $3,368, P = .42). Unadjusted rates of heparin-induced thrombocytopenia (index:0.1% vs 0.3%; post-discharge: 0.02% vs 0.06%) were reported for enoxaparin and UFH, respectively. Conclusion: In contemporary U.S. hospital practice, statistically significant lower odds of VTE, all-cause mortality and major bleeding with enoxaparin versus UFH prophylaxis were found during abdominal surgery hospitalizations.

Efficacy and Safety of Low Molecular Weight Heparin Versus Unfractionated Heparin for Prevention of Venous Thromboembolism in Trauma Patients: A Systematic Review and Meta-analysis

PURPOSE

Trauma patients are at high risk of VTE. We summarize the efficacy and safety of LMWH versus UFH for the prevention of VTE in trauma patients.

METHODS

We searched 6 databases from inception through March 12, 2021. We included randomized controlled trials (RCTs) or observational studies comparing LMWH versus UFH for thromboprophylaxis in adult trauma patients. We pooled effect estimates across RCTs and observational studies separately, using random-effects model and inverse variance weighting. We assessed risk of bias using the Cochrane tool for RCTs and the Risk of Bias in Non-Randomized Studies (ROBINS)-I tool for observational studies and assessed certainty of findings using Grading of Recommendations, Assessment, Development and Evaluations methodology.

RESULTS

We included 4 RCTs (879 patients) and 8 observational studies (306,747 patients). Based on pooled RCT data, compared to UFH, LMWH reduces deep vein thrombosis (RR 0.67, 95% CI 0.50 to 0.88, moderate certainty) and VTE (RR 0.68, 95% CI 0.51 to 0.90, moderate certainty). As compared to UFH, LMWH may reduce pulmonary embolism [adjusted odds ratio from pooled observational studies 0.56 (95% CI 0.50 to 0.62)] and mortality (adjusted odds ratio from pooled observational studies 0.54, 95% CI 0.45 to 0.65), though based on low certainty evidence. There was an uncertain effect on adverse events (RR from pooled RCTs 0.80, 95% CI 0.48 to 1.33, very low certainty) and heparin induced thrombocytopenia [RR from pooled RCTs 0.26 (95% CI 0.03 to 2.38, very low certainty)].

CONCLUSIONS

Among adult trauma patients, LMWH is superior to UFH for deep vein thrombosis and VTE prevention and may additionally reduce pulmonary embolism and mortality. The impact on adverse events and heparin induced thrombocytopenia is uncertain.

Acute Respiratory Failure

Acute respiratory failure occurs when the lungs fail to oxygenate arterial blood adequately and it is one of the commonest postoperative complications. The preoperative identification of risk factors for postoperative acute respiratory failure allows identification of those patients who may benefit from preoperative optimization and increased postoperative vigilance. Multiple postoperative pulmonary complications are associated with acute hypoxemic respiratory failure and this chapter discusses atelectasis, pulmonary embolism, aspiration, and acute respiratory distress syndrome in detail, as well as providing a unified clinical approach to the acutely hypoxemic perioperative patient.

Guideline No. 417: Prevention of Venous Thromboembolic Disease in Gynaecological Surgery

OBJECTIVE

The primary objective of this clinical practice guideline is to provide gynaecologists with an algorithm and evidence to guide the use of thromboprophylaxis in gynaecological surgery.

TARGET POPULATION

All patients undergoing gynaecological surgery for benign or malignant indications.

BENEFITS, HARMS, AND COSTS

The implementation of this guideline will benefit patients undergoing gynaecological surgery and provide physicians with a standard algorithm for the use of perioperative thromboprophylaxis.

EVIDENCE

The following search terms were entered into MEDLINE, Google Scholar, and Cochrane in 2017 and 2018: VTE, PE, DVT, thromboprophylaxis, gynaecological surgery, heparin, graduated compression stocking, intermittent pneumatic stocking, obesity, pediatrics, minimally invasive surgery, heparin induced thrombocytopenia, regional anesthesia). Articles included were randomized controlled trials, meta-analyses, systematic reviews, and observational studies. Additional publications were identified from the reference lists of these articles. There were no date limits, but search results were limited to English language articles only. Searches were updated and incorporated into the guideline up to September 2018.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED USERS

Gynaecologists and other members of the surgical team. RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Audit and Feedback to Surgery Interns and Residents on Prescribing Risk-Appropriate Venous Thromboembolism Prophylaxis

OBJECTIVE

To evaluate the effectiveness of feedback using an emailed scorecard and a web-based dashboard on risk-appropriate VTE prophylaxis prescribing practices among general surgery interns and residents.

DESIGN

Prospective cohort study.

SETTING

The Johns Hopkins Hospital, an urban academic medical center.

PARTICIPANTS

All 45 trainees (19 post-graduate year [PGY] 1 interns and 26 PGY-2 to PGY-5 residents) in our general surgery program.

INTERVENTION

Feedback implementation encompassed three sequential periods: (1) scorecard (July 1, 2014 through June 30, 2015); (2) no feedback/wash-in (July 1 through October 31, 2015); and (3) web-based dashboard (November 1, 2015 through June 30, 2016). No feedback served as the baseline period for the intern cohort. The scorecard was a static document showing an individual's compliance with risk-appropriate VTE prophylaxis prescription compared to compliance of their de-identified peers. The web-based dashboard included other information (e.g., patient details for suboptimal prophylaxis orders) besides individual compliance compared to their de-identified peers. Trainees could access the dashboard anytime to view current and historic performance. We sent monthly emails to all trainees for both feedback mechanisms. Main outcome was proportion of patients prescribed risk-appropriate VTE prophylaxis, and mean percentages reported.

RESULTS

During this study, 4088 VTE prophylaxis orders were placed. Among residents, mean prescription of risk-appropriate prophylaxis was higher in the wash-in (98.4% vs 95.6%, p < 0.001) and dashboard (98.4 vs 95.6%, p < 0.001) periods compared to the scorecard period. There was no difference in mean compliance between the wash-in and dashboard periods (98.4% vs 98.4%, p = 0.99). Among interns, mean prescription of risk-appropriate VTE prophylaxis improved between the wash-in and dashboard periods (91.5% vs 96.4%, p < 0.001).

CONCLUSIONS AND RELEVANCE

Using audit and individualized performance feedback to general surgery trainees through a web-based dashboard improved prescribing of appropriate VTE prophylaxis to a near-perfect performance.

A Review of Current and Future Antithrombotic Strategies in Surgical Patients-Leaving the Graduated Compression Stockings Behind?

Venous thromboembolism (VTE) remains an important consideration within surgery, with recent evidence looking to refine clinical guidance. This review provides a contemporary update of existing clinical evidence for antithrombotic regimens for surgical patients, providing future directions for prophylaxis regimens and research. For moderate to high VTE risk patients, existing evidence supports the use of heparins for prophylaxis. Direct oral anticoagulants (DOACs) have been validated within orthopaedic surgery, although there remain few completed randomised controlled trials in other surgical specialties. Recent trials have also cast doubt on the efficacy of mechanical prophylaxis, especially when adjuvant to pharmacological prophylaxis. Despite the ongoing uncertainty in higher VTE risk patients, there remains a lack of evidence for mechanical prophylaxis in low VTE risk patients, with a recent systematic search failing to identify high-quality evidence. Future research on rigorously developed and validated risk assessment models will allow the better stratification of patients for clinical and academic use. Mechanical prophylaxis' role in modern practice remains uncertain, requiring high-quality trials to investigate select populations in which it may hold benefit and to explore whether intermittent pneumatic compression is more effective. The validation of DOACs and aspirin in wider specialties may permit pharmacological thromboprophylactic regimens that are easier to administer.

Guidelines for the acute care of severe limb trauma patients

GOAL

To provide healthcare professionals with comprehensive multidisciplinary expert recommendations for the acute care of severe limb trauma patients, both during the prehospital phase and after admission to a Trauma Centre.

DESIGN

A consensus committee of 21 experts was formed. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e., pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Few recommendations remained non-graded.

METHODS

The committee addressed eleven questions relevant to the patient suffering severe limb trauma: 1) What are the key findings derived from medical history and clinical examination which lead to the patient's prompt referral to a Level 1 or Level 2 Trauma Centre? 2) What are the medical devices that must be implemented in the prehospital setting to reduce blood loss? 3) Which are the clinical findings prompting the performance of injected X-ray examinations? 4) What are the ideal timing and modalities for performing fracture fixation? 5) What are the clinical and operative findings which steer the surgical approach in case of vascular compromise and/or major musculoskeletal attrition? 6) How to best prevent infection? 7) How to best prevent thromboembolic complications? 8) What is the best strategy to precociously detect and treat limb compartment syndrome? 9) How to best and precociously detect post-traumatic rhabdomyolysis and prevent rhabdomyolysis-induced acute kidney injury? 10) What is the best strategy to reduce the incidence of fat emboli syndrome and post-traumatic systemic inflammatory response? 11) What is the best therapeutic strategy to treat acute trauma-induced pain? Every question was formulated in a PICO (Patient Intervention Comparison Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 19 recommendations. Among the formalised recommendations, 4 had a high level of evidence (GRADE 1+/-) and 12 had a low level of evidence (GRADE 2+/-). For 3 recommendations, the GRADE method could not be applied, resulting in an expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations.

CONCLUSIONS

There was significant agreement among experts on strong recommendations to improve practices for severe limb trauma patients.

Construction and Validation of a Nomogram for Predicting the Risk of Deep Vein Thrombosis in Hepatocellular Carcinoma Patients After Laparoscopic Hepatectomy: A Retrospective Study

Background

The incidence of deep vein thrombosis (DVT) in hepatocellular carcinoma (HCC) patients after laparoscopic hepatectomy (LH) is unclear, and there is no effective method for DVT risk assessment in these patients.

Methods

The data from the total of 355 consecutive HCC patients who underwent LH were included. A DVT risk algorithm was developed using a training set (TS) of 243 patients, and its predictive performance was evaluated in both the TS and a validation set (VS) of 112 patients. The model was then used to develop a DVT risk nomogram (TRN).

Results

The incidence of DVT in the present study was 18.6%. Age, sex, body mass index (BMI), comorbidities and operative position were independent risk factors for DVT in the TS. The model based on these factors had a good predictive ability. In the TS, it had an area under the receiver operating characteristic (AUC) curve of 0.861, Hosmer-Lemeshow (H-L) goodness of fit p value of 0.626, sensitivity of 44.4%, specificity of 96.5%, positive predictive value (PPV) of 74.1%, negative predictive value (NPV) of 88.4%, and accuracy of 86.8%. In the VS, it had an AUC of 0.818, H-L p value of 0.259, sensitivity of 38.1%, specificity of 98.9%, PPV of 88.9%, NPV of 87.4%, and accuracy of 87.5%. The TRN performed well in both the internal and the external validation, indicating a good clinical application value. The TRN had a better predictive value of DVT than the Caprini score (p < 0.001).

Conclusion

The incidence of DVT after LH was high, and should not be neglected in HCC patients. The TRN provides an efficacious method for DVT risk evaluation and individualized pharmacological thromboprophylaxis.

Incidence and Nature of Lower-Limb Deep Vein Thrombosis in Patients with Polytrauma on Thromboprophylaxis: A Prospective Cohort Study

Purpose

Deep vein thrombosis (DVT) is common among the severely injured and may lead to pulmonary embolism (PE), which can be life threatening. Thromboprophylaxis may reduce the incidence of venous thromboembolism (VTE); it does not guarantee complete protection. This study’s primary aim was to determine the incidence and nature of lower-limb DVT in polytrauma patients taking prophylaxis. The secondary objective was to assess the incidence of DVT-related complications, including the development of PE and death.

Patients and Methods

This prospective observational study included patients age 18 years or older who presented with polytrauma directly from the scene and were admitted into the trauma unit between March 1, 2020 and August 31, 2020. All patients underwent lower-limb ultrasound during their hospital course to diagnose DVT.

Results

A total of 169 patients underwent extremity Doppler ultrasound to detect DVT. Of these, 69 patients (40.8%) were considered at the highest-risk for VTE development. For VTE prophylaxis, 115 patients (68%) received pharmacologic agents, and 54 patients (32%) had intermittent pneumatic compression on admission. Three patients (1.8%) developed DVT despite prophylaxis. Four patients (2.4%) developed PE during the index presentation and were diagnosed between days 3 and 13 after injury. Early DVT was not detected in any patients with diagnosed PE. Overall, nine patients (5.33%) died, but no in-hospital deaths were related to DVT and/or PE.

Conclusion

The incidence of DVT in polytrauma patients remains low in our small series, perhaps because of the mandatory VTE risk assessment for all hospitalized patients and the early initiation of prophylaxis. Using a trauma center registry to measure DVT and PE incidence regularly is recommended to improve trauma care quality.

Can Intermittent Pneumatic Compression Reduce the Incidence of Venous Thrombosis in Critically Ill Patients: A Systematic Review and Meta-Analysis

Venous thromboembolism (VTE) is a common complication for critically ill patients. Intermittent pneumatic compression (IPC) is recommended for patients with high risk of bleeding. We aim to evaluate the effectiveness of IPC for thromboprophylaxis in critically ill patients. We searched PubMed, Embase, and ClinicalTrials for randomized controlled trials (RCTs) and observational studies that evaluated IPC in critically ill patients. RevMan 5.3 software was used for the meta-analysis. A total of 10 studies were included. The IPC group significantly reduced the VTE incidence compared with no thromboprophylaxis group (risk ratio [RR]: 0.35, confidence interval [CI]: 0.18-0.68, P = .002) and the IPC group also showed lower VTE incidence than the graduated compression stockings (GCS) group (RR: 0.47, CI: 0.24-0.91, P = .03). There were no significant differences between using IPC and low-molecular-weight heparin (LMWH) for VTE incidence (RR: 1.26, CI: 0.72-2.22, P = .41), but LMWH showed significantly more bleeding events. Intermittent pneumatic compression as an adjunctive treatment did not further reduce VTE incidence (RR: 0.55, CI: 0.24-1.27, P = .16). Intermittent pneumatic compression can reduce the incidence of VTE for critically ill patients, which is better than GCS and similar to LMWH, but it has no significant advantage as an adjunct therapy for thromboprophylaxis.

Prevention of Venous Thromboembolism in Gynecologic Surgery: ACOG Practice Bulletin, Number 232

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as "venous thromboembolic events" (VTE). Despite advances in prophylaxis, diagnosis, and treatment, VTE remains a leading cause of cost, disability, and death in postoperative and hospitalized patients (1, 2). Beyond the acute sequelae of leg pain, edema, and respiratory distress, VTE may result in chronic conditions, including postthrombotic syndrome (3), venous insufficiency, and pulmonary hypertension. This Practice Bulletin has been revised to reflect updated literature on the prevention of VTE in patients undergoing gynecologic surgery and the current surgical thromboprophylaxis guidelines from the American College of Chest Physicians (4). Discussion of gynecologic surgery and chronic antithrombotic therapy is beyond the scope of this document.

Should all patients receive the same prophylaxis? Racial variation in the risk of venous thromboembolism after major abdominal operations

BACKGROUND

Whether prevention strategy for postoperative venous thromboembolism (VTE) should be tailored across racial groups remains unknown.

METHODS

Patients who underwent major abdominal operation in the Nationwide Inpatient Sample (NIS) were examined. Our primary outcome was postoperative VTE, and the secondary outcome was postoperative bleeding. Multivariable logistic regression analyses were performed and validated with the National Surgical Quality Improvement Program (NSQIP) database.

RESULTS

781,888 patients from NIS were analyzed. Overall VTE rate was 2.0%. Compared to White patients, Hispanic (OR 0.85, 95% CI 0.78-0.93, p < 0.01) and Asian patients (OR 0.49, 95% CI 0.40-0.61, p < 0.01) had significantly lower risks for VTE. In contrast, Asian patients had a significantly higher risk of bleeding (OR 1.39, 95% CI 1.24-1.56, p < 0.01). Similar trends were observed in NSQIP.

CONCLUSIONS

The risk-benefit ratio of postoperative VTE prophylaxis for Asian patients is roughly three times higher than that for White patients, suggesting a tailored approach is necessary.

Unfractionated heparin as a safe alternative in a case of low molecular weight heparin-induced thrombocytosis: A case report

Introduction and importance

Low molecular weight heparins are rarely associated with thrombocytosis. However, the safety of transitioning to unfractionated heparin is unknown.

Case presentation

We report a case of a 47-year-old South Asian male who presented to the hospital after ingestion of a caustic liquid. He received subcutaneous enoxaparin 40 mg once daily for prophylaxis against venous thromboembolism. His platelet count increased from the baseline of 748 × 10⁹/L to a peak of 1213 × 10⁹/L, after which enoxaparin was changed to unfractionated heparin. His platelet count returned to normal within seven days. The modified Naranjo scale with thrombocytosis-specific criteria was 6, indicating a probable association with enoxaparin.

Clinical discussion

In this case, the patient developed thrombocytosis after initiation of low-molecular weight heparin and platelet count normalized after shifting to unfractionated heparin.

Conclusion

Clinicians should suspect LMWH-induced thrombocytosis when platelet count elevation cannot be explained by other causes. Unfractionated heparin might be a safe alternative in case of low molecular weight heparin-induced thrombocytosis.

•

Low molecular weight heparin-induced thrombocytosis is a rare adverse drug reaction.

•

Clinicians should anticipate low molecular weight induced thrombocytosis when other causes of thrombocytosis are excluded.

•

Unfractionated heparin may be a safe therapeutic alternative in case of low molecular weight induced thrombocytosis.

Efficacy and safety of short-term (3 days) enoxaparin in preventing venous thromboembolism after gastric cancer surgery: A single-center, prospective cohort study

BACKGROUND

Pharmacologic prophylaxis such as enoxaparin for venous thromboembolism (VTE) is rarely used in Japan, even following abdominal cancer surgery, for which it is recommended in relevant guidelines (at least 7 days of use) along with mechanical prophylaxis with intermittent pneumatic compression. Reasons for enoxaparin's unpopularity include concerns over postoperative bleeding and its inconvenience in clinical practice. Here, we conducted a prospective clinical study of short-term (3 days) use of enoxaparin, which is considered to minimally impact postoperative management without increasing bleeding risk.

METHODS

Gastric cancer patients who underwent gastrectomy received enoxaparin for 3 days from postoperative day (POD) 1-4. The primary endpoint was the incidence of deep vein thrombosis (DVT), which was examined primarily via Doppler ultrasonography of the lower limbs between POD 8 and 14. The planned sample size was 70, which was calculated based on an estimated incidence rate of 9% and an upper limit of incidence rate of 20%, with alpha of 0.05 and beta of 0.2.

RESULTS

A total of 70 gastric cancer patients were enrolled, and ultimately, 68 patients received the protocol intervention and DVT evaluation. Sixty-seven patients completed 6 enoxaparin injections, but 1 patient did not complete the course due to abdominal bleeding after initiation. The incidence of DVT was 4.4% (3/68), and the 95% upper confidence interval was 12.2%, lower than the 20% threshold we set as the upper limit of DVT incidence. DVT was detected only in the peripheral veins of the lower extremities in all 3 affected patients. The incidence of bleeding-related complications, which were not severe, was 1.5% (1/68).

CONCLUSIONS

Short-term (3 days) use of enoxaparin was shown to be effective and safe for VTE prophylaxis, comparable to regular use (at least 7 days), in postoperative management of gastric cancer surgery.

Pharmacological and clinical application of heparin progress: An essential drug for modern medicine

Heparin is the earliest and most widely used anticoagulant and antithrombotic drug that is still used in a variety of clinical indications. Since it was discovered in 1916, after more than a century of repeated exploration, heparin has not been replaced by other drugs, but a great progress has been made in its basic research and clinical application. Besides anticoagulant and antithrombotic effects, heparin also has antitumor, anti-inflammatory, antiviral, and other pharmacological activities. It is widely used clinically in cardiovascular and cerebrovascular diseases, lung diseases, kidney diseases, cancer, etc., as the first anticoagulant medicine in COVID-19 exerts anticoagulant, anti-inflammatory and antiviral effects. At the same time, however, it also leads to a lot of adverse reactions, such as bleeding, thrombocytopenia, elevated transaminase, allergic reactions, and others. This article comprehensively reviews the modern research progress of heparin compounds; discusses the structure, preparation, and adverse reactions of heparin; emphasizes the pharmacological activity and clinical application of heparin; reveals the possible mechanism of the therapeutic effect of heparin in related clinical applications; provides evidence support for the clinical application of heparin; and hints on the significance of exploring the wider application fields of heparin.

Complications and functional outcomes after ileo-anal pouch excision-a systematic review of 14 retrospective observational studies

PURPOSE

The ileo-anal pouch (IAP) has been the gold standard procedure for maintenance of bowel continuity after panproctocolectomy for ulcerative colitis, familial adenomatous polyposis or hereditary non-polyposis colorectal cancer. However, the IAP has an estimated failure rate of 13% at 10 years post-procedure (Tulchinsky et al., Ann Surg 238(2):229-34, 2003), which can result in pouch excision (P.E.). This systematic review aims to synthesise all the available studies reporting post-operative outcomes of P.E. and its impact on patient quality of life (QoL), when available, which have not previously been summarised.

METHODS

PubMed, Embase, Medline and the Cochrane library databases were searched with terms 'Pouch AND excision' OR 'Pouch AND removal' OR 'Pouch AND remove' OR 'IAP AND excision'. All studies reporting post-operative morbidity, mortality or functional outcomes in patients who had P.E. were included. Studies with < 5 patients, non-English studies and conference abstracts were excluded.

RESULTS

14 studies comprising 1601 patients were included. Overall complications varied from 18 to 63% with the most common being persistent perineal sinus (9-40%) or surgical site infection (wound-2 to 30%; intra-abdominal collection-3 to 24%). The mortality rate was between 0.58 and 1.4%. QoL is generally lower in P.E. patients compared to the normal population across various QoL measures and P.E. patients often had urinary and sexual dysfunction post-operatively.

CONCLUSIONS

There is a substantial incidence of complications after P.E.; however, there is no evidence describing QoL pre- and post-P.E. Further longitudinal research comparing QoL in patients undergoing P.E. and other treatment options such as indefinite diversion is required to definitively assess QoL post-procedure.

Rationalizing post-operative prophylactic anticoagulation in reconstructive head and neck cancer patients: a review

Microsurgical reconstructive head and neck cancer patients are at high risk of venous thromboembolism. The use of anticoagulation can reduce their risk; however, this also increases their bleeding risk. It is not clear whether the benefits of treatment outweigh the risks, and whether a specific post-operative anticoagulation regime is superior. The aim of this review is to evaluate the evidence pertaining to the risks and benefits of post-operative anticoagulation and to provide a rationale for its use in head and neck cancer patients receiving free flaps. The secondary aim was to determine the optimal post-operative anticoagulation regimen. A search was conducted in the PubMed and EMBASE databases identifying studies reporting venous thromboembolism rates in reconstructive head and neck cancer patients undergoing free flaps. These studies were reviewed for their eligibility. Outcomes measured were rates of venous thromboembolism, bleeding-related and microsurgical complications. A total of 306 studies were found from the search with another seven studies identified from citations of key articles. After assessment, nine studies were included. Venous thromboembolism rates ranged from 0.5% to 7% and the rates of bleeding-related complications ranged from 2.4% up to 29%. Anticoagulation appears to lower the risk of venous thromboembolism in this patient group, but also increases the bleeding risk. Risk stratification using the Caprini risk assessment model can help surgeons make decisions. For patients with cancer, low molecular weight heparin appears to be superior to heparin given twice daily but equal to heparin given three times daily and the bleeding risk of each medication appears similar.

A Prospective Multicenter Observational Study of Venous Thromboembolism after Gastric Cancer Surgery (SHISA-1601)

INTRODUCTION

This study aimed to clarify the frequency and risk factors of intercurrent venous thromboembolism (VTE) in patients undergoing major curative gastric cancer surgery.

METHODS

This prospective, multicenter, observational study included patients with gastric cancer who underwent radical gastrectomy at 5 hospitals between June 2016 and May 2018. Patients who were preoperatively administered anticoagulants were excluded.

RESULTS

A total of 126 patients were eligible to participate. VTE occurred within 9 days postoperatively in 5 cases (4.0%; 2 symptomatic and 3 asymptomatic). Postoperative day (POD) 1 plasma D-dimer and soluble fibrin (SF) levels were significantly higher in the VTE group than in the non-VTE group. Receiver-operating characteristic curve (ROC) analysis indicated a statistically significant ability of POD 1 D-dimer and SF levels to predict postoperative VTE development after gastrectomy; this finding was reflected by an area under the curve (AUC) of 0.97 (95% CI 0.92-1.0) and 0.87 (95% CI 0.74-1.0), respectively. Cutoff values of D-dimer (24.6 µg/mL) and SF (64.1 µg/mL) were determined. Intraoperative blood transfusion (odds ratio [OR] 7.86), POD 1 D-dimer ≥24.6 µg/mL (OR 17.35), and POD 1 SF ≥64.1 µg/mL (OR 19.5) were independent predictive factors for postoperative VTE (p < 0.05).

CONCLUSION

VTE occurred in 4.0% patients (1.6% symptomatic and 2.4% asymptomatic) after gastric cancer surgery; however, with an early diagnosis and anticoagulant therapy, no patients experienced progression. Careful observation of patients with a high risk for VTE, including intraoperative blood transfusion and high POD 1 D-dimer or SF levels, would contribute to the early detection of VTE.

A Machine Learning Approach to Predict Deep Venous Thrombosis Among Hospitalized Patients

Deep venous thrombosis (DVT) is associated with significant morbidity, mortality, and increased healthcare costs. Standard scoring systems for DVT risk stratification often provide insufficient stratification of hospitalized patients and are unable to accurately predict which inpatients are most likely to present with DVT. There is a continued need for tools which can predict DVT in hospitalized patients. We performed a retrospective study on a database collected from a large academic hospital, comprised of 99,237 total general ward or ICU patients, 2,378 of whom experienced a DVT during their hospital stay. Gradient boosted machine learning algorithms were developed to predict a patient's risk of developing DVT at 12- and 24-hour windows prior to onset. The primary outcome of interest was diagnosis of in-hospital DVT. The machine learning predictors obtained AUROCs of 0.83 and 0.85 for DVT risk prediction on hospitalized patients at 12- and 24-hour windows, respectively. At both 12 and 24 hours before DVT onset, the most important features for prediction of DVT were cancer history, VTE history, and internal normalized ratio (INR). Improved risk stratification may prevent unnecessary invasive testing in patients for whom DVT cannot be ruled out using existing methods. Improved risk stratification may also allow for more targeted use of prophylactic anticoagulants, as well as earlier diagnosis and treatment, preventing the development of pulmonary emboli and other sequelae of DVT.

Anti-Factor Xa Levels in Low-weight Surgical Patients Receiving Enoxaparin for Venous Thromboembolism Prophylaxis: A Prospective Cohort Study

Enoxaparin is indicated for thromboprophylaxis in non-orthopedic surgical patients at a fixed dose of 40 mg daily. According to the US Food and Drug Administration’s enoxaparin prescribing information, this dose exposes low-weight patients (males < 57 kg, females < 45 kg) to a higher risk of bleeding. This study aimed to determine the rate of achieving a prophylactic peak anti-factor Xa (AFXa) level in low-weight surgical patients using enoxaparin 30 mg daily. Low-weight patients admitted for abdominopelvic or noncardiac thoracic surgery from May 2018 to May 2019 were prospectively studied. After receiving daily enoxaparin 30 mg, peak AFXa levels were assessed for achieving a prophylactic level (0.2-0.5 IU/mL). In 121 patients, the proportion of achieving a prophylactic peak AFXa level was 66.1%. More females (84.8%) achieved a prophylactic level compared to males (54.7%, P = .001). All out-of-range peak AFXa levels (33.9%) were sub-prophylactic. The median peak AFXa level was lower in males (0.24 [0.1-0.47] IU/mL) than females (0.31 [0.1-0.5] IU/mL; P < .001). On univariate analysis, female sex and weight were associated with achieving a prophylactic peak AFXa level. On multivariate analysis, only female sex was independently associated with an adequate prophylactic AFXa level (odds ratio 3.17, 95% CI: 1.32-11.94; P = .014). Four venous thromboembolism events (3.3%) were observed in patients with sub-prophylactic peak AFXa levels (9.7%). Two-thirds of low-weight surgical patients achieved a prophylactic peak AFXa level using daily enoxaparin 30 mg. This dose is likely to provide adequate thromboprophylaxis in low-weight females.

Prevention, diagnosis, and management of venous thromboembolism in the critically ill surgical and trauma patient

PURPOSE OF REVIEW

Venous thromboembolism (VTE), which encompasses deep vein thrombosis and pulmonary embolism, is common among trauma patients and critically ill surgical patients admitted to the ICU. Critical care surgical patients are at an extremely high risk for VTE and the related morbidity and mortality associated with it. The present review aims to provide an overview of the importance of identifying risk factors, prescribing effective prohylaxis, accurate diagnosis, and timely appropriate treatment for trauma and critically ill surgical patients with VTE in the ICU.

RECENT FINDINGS

VTE is a healthcare burden among critically ill surgical patients that is mostly preventable through adherence to prophylactic protocols that aim to recognize VTE risk factors while simultaneously providing guidance to appropriate timing and administration prophylaxis regimens. Newer pharmacologic therapies for prophylaxis and treatment, diagnostic modalities, and indications for therapy of VTE have continued to evolve.

SUMMARY

Critical care surgical and trauma patients represent a population that are at a heightened risk for VTE and associated complications. Appropriate screening, prevention strategies, accurate diagnosis, and timely administration of appropriate treatment must be utilized to reduce morbidity and mortality.

Venous Thromboembolism Prophylaxis and Thrombotic Risk Stratification in the Varicose Veins Surgery-Prospective Observational Study

Background: An invasive phlebological treatment is still not free from complications such as thrombosis. As in other surgical populations, not only the treatment modality, but also patient condition-related venous thromboembolism (VTE) risk factors matter. The current protocols used in varicose vein surgery centers are based mostly on individual risk assessment as well as on an implementation and extrapolation of general surgery VTE prophylaxis guidelines. In the presented study, the efficacy of routine VTE pharmacological thromboprophylaxis in patients undergoing saphenous varicose vein surgery was prospectively evaluated. In the result assessment, VTE risk factor evaluation and Caprini score results were included; however, due to the limited size of the projected study group, as well as expected limited deep vein thrombosis (DVT) prevalence in this clinical scenario, it was not possible to perform the validation of the Caprini model efficacy in the projected study model. Methods: In the study, 141 patients undergoing saphenous vein stripping and miniphlebectomy in spinal anesthesia were included. In all of the patients, VTE risk factors (including Caprini score evaluation) were assessed, and the routine thromboprophylaxis with enoxaparin 40 mg for 10 days was used. The venous ultrasounds were undertaken before the surgery and on the 10th and 30th day after surgery. The study endpoint was the presence of symptomatic or asymptomatic DVT confirmed in the imaging study. The study safety endpoint was major bleeding occurrence intraoperatively or within 30 days after surgery. Results: The presence of a postoperative DVT was diagnosed in five cases (3.5%) In all of these cases, only distal DVT was confirmed. Despite extensive saphenous varicose vein surgery with stripping and miniphlebectomy performed in nontumescent but spinal anesthesia, no proximal lower leg episode was diagnosed. Three out of five DVT cases were diagnosed on day 10 postoperative control, while a further two were confirmed in the ultrasound examination performed 30 days after procedure. No clinically documented pulmonaly embolism (PE) as well as no bleeding episodes were noticed. Among the factors related to the statistically significant higher DVT occurrence, the results of the Caprini score were identified with odds ratio (OR) = 2.04 (95% CI = (0.998; 4.18)). Another factor that became statistically significant in terms of the higher postoperative DVT prevalence was the reported Venous Clinical Severity Score (VCSS) results (OR = 1.98; 95% CI (1.19; 3.26)). In the multiple logistic regression analysis, the patient age (OR = 0.86; 95% CI (0.75–0.99)), Caprini score evaluation results (OR = 4.04; 95% CI (1.26–12.9)) and VCSS results (OR = 2.4; 95% CI (1.23–4.7)) were of statistical significance as predictors for postoperative DVT occurrence, with a p value of 0.029 for age, and p = 0.017 and p = 0.009 for Caprini score results and VCSS results, respectively. Due to the confirmed limited number of the DVT events in our study cohort, as well as the descriptive and explorative nature of the achieved results, the final clinical potential and significance of the identified parameters, including Caprini score rate and VCSS rate, should be interpreted with caution and studied in the further trials in these clinical settings. Conclusion: All the patients undergoing varicose vein surgery should undergo VTE risk evaluation based on the individual assessment. In VTE risk evaluation, patient and surgical procedure characteristics based on the factors included into the Caprini score but also on specific chronic venous disease-related factors should be taken into consideration. Further studies are needed to propose an objective and validated VTE risk assessment model, as well as a validated antithrombotic prophylaxis protocol in this particular patient group.

Thromboprophylaxis practice patterns and beliefs among physicians treating patients with abdominopelvic cancers at a Canadian centre

Background

There is inadequate high-quality evidence on thromboprophylaxis for patients undergoing surgery for abdominopelvic cancer. We surveyed physicians who treat patients with abdominopelvic cancer to determine current thromboprophylaxis practice patterns and to determine where research is needed.

Methods

We created an online survey with questions on thromboprophylaxis topics, including type of thromboprophylaxis used, timing of initial thromboprophylaxis dose, use of thromboprophylaxis during chemotherapy, use of extended-duration thromboprophylaxis and areas for future research. The survey questions were reviewed by external content experts to ensure they were appropriate and relevant. Surgeons, thrombosis experts and medical oncologists who manage patients with abdominopelvic cancers at 1 large Canadian academic centre were invited to complete the survey between January and April 2019.

Results

Of the 57 physicians invited, 42 (74%) completed the survey, including 27 surgeons (response rate 79%), 9 thrombosis experts (response rate 75%) and 6 medical oncologists (response rate 55%). Most surgeons (22 [82%]) reported using mechanical thromboprophylaxis, whereas only 1 thrombosis expert (11%) recommended mechanical thromboprophylaxis. There was substantial variability in the timing of the initial dose of thromboprophylaxis, with 9/10 urologists (90%) and all 7 general surgeons giving the first dose intraoperatively, and three-quarters of thoracic surgeons (3/4 [75%]), gynecologists (3/4 [75%]) and thrombosis experts (7/9 [78%]) starting thromboprophylaxis after surgery. All medical oncologists believed chemotherapy increases the risk of venous thromboembolism, but 4 (67%) reported that they do not routinely prescribe thromboprophylaxis owing to bleeding concerns. Most respondents (35/38 [92%]) felt there was a need for more research on thromboprophylaxis and indicated willingness to participate in future clinical trials.

Conclusion

Variability exists in contemporary thromboprophylaxis practice patterns among physicians treating patients with abdominopelvic cancer. Future research is needed to standardize care and improve outcomes for patients.

Direct oral anticoagulant use in gynecologic oncology: A Society of Gynecologic Oncology Clinical Practice Statement

Venous thromboembolism (VTE) is a common cause of morbidity and mortality in women with gynecologic malignancies. This practice statement provides clinical data and overall quality of evidence regarding the use of direct oral anticoagulants (DOACs) in this patient population. Specifically, it reviews patient selection, safety measures, and nuances of perioperative use of these medications. The scope of this document is limited to DOAC use in gynecologic oncology rather than a broad discussion of VTE prophylaxis and management in general. The following recommendations and examination of extant data are based on DOAC trials conducted primarily in mixed populations with different cancer subtypes. Many of these trials include few, or no, women with gynecologic cancer. However, because there is very limited data in gynecologic cancer-specific populations, the results of these studies represent the best available evidence to support treatment recommendations in our patients. The members of the Society of Gynecologic Oncology (SGO) Clinical Practice Committee believe that the results of these studies may be extrapolated, with caution, to VTE treatment and prophylaxis for patients with gynecologic cancer.

Timing and characteristics of venous thromboembolism after noncancer surgery

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity and mortality postoperatively. The use of pharmacologic prophylaxis is effective in reducing the incidence of VTE. However, the prophylaxis is often discontinued at hospital discharge, especially for those with benign disease. The implications of this practice are not known. We assessed the data from a large, ongoing registry regarding the time course of VTE and outcomes after noncancer surgery.

METHODS

We analyzed the RIETE (Computerized Registry on Venous Thromboembolism) registry, which includes data from consecutive patients with symptomatic confirmed VTE. In the present study, we focused on general surgical patients who had developed symptomatic postoperative VTE in the first 8 weeks after noncancer surgery. The main objective was to assess the interval between surgery and the occurrence of VTE. Additional variables included the clinical presentation associated with the event, the use of thrombosis prophylaxis, and unfavorable outcomes.

RESULTS

The data from 3296 patients were analyzed. The median time from surgery to the detection of VTE was 16 days (interquartile range, 8-30 days). Of the VTE events, 77% were detected after the first postoperative week and 27% after 4 weeks. Overall, 43.9% of the patients with VTE had received pharmacologic prophylaxis after surgery for a median of 8 days (interquartile range, 5-14 days), and three quarters of the VTE events were detected after pharmacologic prophylaxis had been discontinued. Overall, 54% of the patients with VTE had presented with pulmonary embolism. For 15% of the patients, the clinical outcome was unfavorable, including 4% who had died within 90 days.

CONCLUSIONS

The risk of VTE after noncancer general surgery remains high for ≤2 months. More than one half of the patients had presented with symptomatic PE as the VTE event, and 15% had had unfavorable outcomes. Only 44% of these patients had received pharmacologic prophylaxis for around 1 week.

Variations in practice of thromboprophylaxis across general surgical subspecialties: a multicentre (PROTECTinG) study of elective major surgeries

BACKGROUND

Despite guidelines recommending perioperative thromboprophylaxis for patients undergoing general surgery, we have observed significant variations in its practice. This may compromise patient safety. Here, we quantify the heterogeneity of perioperative thromboprophylaxis across all major general surgical operations, and place them in relation to their risk of bleeding and venous thromboembolism.

METHODS

Retrospective review of all elective major general surgeries performed between 1 January 2018 and 30 June 2019 across seven Victorian hospitals was conducted.

RESULTS

A total of 5912 patients who underwent 6628 procedures were reviewed. Significant heterogeneity was found in the use of chemoprophylaxis, timing of its initiation, type of anticoagulant administered and application of extended chemoprophylaxis. These variations were observed within the same procedure, and between different surgeries and subspecialties. Contrastingly, there was minimal heterogeneity with the use of mechanical thromboprophylaxis. Oesophago-gastric, liver and colorectal cancer resections had the highest thromboembolic risk. Breast, oesophago-gastric, liver, pancreas and colon cancer resections had the highest bleeding risk.

CONCLUSION

Perioperative chemoprophylaxis across general surgery is highly variable. This study has highlighted key areas of variance. Our findings also enable surgeons to compare their practices, and provide baseline data to inform future efforts towards optimizing thromboprophylaxis for general surgical patients.