A validated risk model to predict 90-day VTE events in postsurgical patients

Racial disparities in extended venous thromboembolism prophylaxis after hysterectomy

BACKGROUND

Venous thromboembolism (VTE) is a significant preventable cause of postoperative morbidity and mortality after major abdominopelvic surgery that calls for extended VTE prophylaxis (eVTEp). Literature suggests that significant racial disparities may exist in post-operative care.

OBJECTIVE

The study sought to examine if racial disparities exist in the administration of eVTEp after hysterectomy in a statewide collaborative.

METHODS

We conducted a retrospective cohort study of post-hysterectomy patients across 69 hospitals in the Michigan Surgical Quality Collaborative from January 2016 to February 2020. The variable of interest was race (Black/African or White American). The primary outcome was administration or absence of eVTEp. Descriptive statistics and mixed effects logistic regression were performed for risk adjustment with covariates such as age, cancer occurrence, inflammatory bowel disease, American Society of Anesthesiologists physical status classification, perioperative VTE prophylaxis, postoperative VTE prophylaxis, surgical approach, and surgical duration, among other variables.

RESULTS

In total, 24,513 patients underwent hysterectomy. Of these patients, 1,107 (4.45%) received eVTEp, 153 (13.24%) of which were Black and 954 (82.53%) of which were White. Mixed effects logistic regression analysis suggested that Black patients were significantly less likely to receive eVTEp than White patients (odds ratio = 0.776; 95% CI: 0.615-0.979; P = 0.039). Additionally, tobacco use, coronary artery disease, bleeding disorder, cancer occurrence, functional status, perioperative VTE prophylaxis, surgical duration, length of stay, and surgical approach were associated with a higher likelihood of receiving eVTEp.

CONCLUSION

eVTEp is recommended for the prevention of post-discharge VTE in select patients after hysterectomy. Regression analysis showed that, compared to their White counterparts, Black females were significantly less likely to receive eVTEp. The underlying reasons for this disparity require further investigation into possible socioeconomic influences and inherent biases.

The Role of Local Flaps in Foot and Ankle Reconstruction: An Assessment of Outcomes across 206 Patients with Chronic Wounds

BACKGROUND

Reconstructive surgery has experienced a paradigm shift in favor of free flaps. Yet local flaps may be of particular use in foot and ankle reconstruction among comorbid patient populations. Thus, the authors sought to better characterize long-term outcomes in this setting.

METHODS

A single-center, retrospective cohort study of patients undergoing local muscle and fasciocutaneous flaps of the foot and ankle from January of 2010 through November of 2022 was performed. Flaps were performed on wounds measuring 3 × 6 cm or smaller; flap selection depended on preoperative vascular assessment, Doppler findings, comorbidity profile, and wound location, depth, and geometry.

RESULTS

A total of 206 patients met inclusion criteria. Their median age was 61.0 years (interquartile range, 16.8), and comorbidities included diabetes mellitus ( n = 149 [72.3%]) and peripheral arterial disease ( n = 105 [51.0%]). Presentations included chronic, nonhealing wounds ( n = 77 [39.1%]) or osteomyelitis ( n = 45 [22.8%]) and most frequently extended to the bone ( n = 128 [62.1%]). Eighty-seven patients (42.2%) received muscle flaps; 119 (57.8%) received fasciocutaneous flaps. Six patients (2.9%) needed return to the operating room, with thrombosis occurring in 2 cases (1.0%). The flap success rate was 98.1%. By a median follow-up duration of 21.7 months (interquartile range, 39.0), 21.8% of patients ( n = 45) required ipsilateral amputation, 73% ( n = 145 of 199) were ambulatory, and 2 deaths related to the surgical wound occurred (2 of 49 [4.1%]). Multivariate analysis revealed that positive predictors of complications included diabetes mellitus, end-stage renal disease, and history of venous thromboembolism or smoking.

CONCLUSION

Local flaps remain a reliable option to reconstruct smaller defects of the foot and ankle in a highly comorbid population.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

A composite risk assessment model for venous thromboembolism

OBJECTIVE

Venous thromboembolism (VTE) is a preventable cause of hospitalization-related morbidity and mortality. VTE prevention requires accurate risk stratification. Federal agencies mandated VTE risk assessment for all hospital admissions. We have shown that the widely used Caprini (30 risk factors) and Padua (11 risk factors) VTE risk-assessment models (RAMs) have limited predictive ability for VTE when used for all general hospital admissions. Here, we test whether combining the risk factors from all 23 available VTE RAMs improves VTE risk prediction.

METHODS

We analyzed data from the first hospitalizations of 1,282,014 surgical and non-surgical patients admitted to 1298 Veterans Affairs facilities nationwide between January 2016 and December 2021. We used logistic regression to predict VTE within 90 days of admission using risk factors from all 23 available VTE RAMs. Area under the receiver operating characteristic curves (AUC), sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) were used to quantify the predictive power of our models. The metrics were computed at two diagnostic thresholds that maximized (1) the value of sensitivity + specificity-1; and (2) PPV and were compared using McNemar's test. The Delong-Delong test was used to compare AUCs.

RESULTS

After excluding those with missing data, 1,185,633 patients (mean age, 66 years; 93% male; and 72% White) were analyzed, of whom 33,253 (2.8%) had a VTE (deep venous thrombosis [DVT], n = 19,218, 1.6%; pulmonary embolism [PE], n = 10,190, 0.9%; PE + DVT, n = 3845, 0.3%). Our composite RAM included 102 risk factors and improved prediction of VTE compared with the Caprini RAM risk factors (AUC composite model: 0.74; AUC Caprini risk-factor model: 0.63; P < .0001). When the sum of sensitivity and specificity-1 was maximized, the composite model demonstrated small improvements in sensitivity, specificity and PPV; NPV was high in both models. When PPV was maximized, the PPV of the composite model was improved but remained low. The nature of the relationship between NPV and PPV precluded any further gain in PPV by sacrificing NPV and sensitivity.

CONCLUSIONS

Using a composite of 102 risk factors from all available VTE RAMs, we improved VTE prediction in a large, national cohort of >1 million general hospital admissions. However, neither model has a sensitivity or PPV that permits it to be a reliable predictor of VTE. We demonstrate the limits of currently available VTE risk prediction tools; no available RAM is ready for widespread use in the general hospital population.

Defect width and operative time are the most significant predictors of venous thromboembolism in ventral hernia repair

BACKGROUND

Venous thromboembolism is a significant cause of morbidity and mortality among patients undergoing ventral hernia repair. Several risk-assessment models have been developed to predict venous thromboembolism risk for various surgical procedures. However, these models do not include hernia-specific risk factors. Therefore, we sought to evaluate the predictors of venous thromboembolism in patients with a ventral hernia repair in a national hernia-specific database.

METHODS

The Abdominal Core Health Quality Collaborative database was retrospectively queried for ventral hernia repair data. The ventral hernia repair procedures were divided into 2 groups on the basis of whether the patients developed perioperative venous thromboembolism. Baseline and operative characteristics and perioperative outcomes were compared between the 2 groups. The logistic regression was used to assess the association between different risk factors and venous thromboembolism.

RESULTS

A total of 43,558 patients were included in the study. The 30-day venous thromboembolism rate among these patients was 0.62% (n = 269). Venous thromboembolism was associated with greater 30-day readmission (odds ratio, 4.29; 95% confidence interval, 3.20-5.76), reoperation (odds ratio, 3.97, 95% confidence interval, 2.63-6.00), and mortality rates (odds ratio, 5.95, 95% confidence interval, 2.62-13.48), all P < .001. Bivariate analysis identified a statistically significant association between several patient characteristics, operation, and hernia- related details; however, multivariate analysis revealed that that only hernia width (each increasing centimeter: odds ratio, 1.07, 95% CI, 1.05-1.09) and operative time compared with 0-59 minutes (60-119 minutes: odds ratio, 4.23; 95% confidence interval, 1.86-9.62; 120-179 minutes: odds ratio, 5.78; 95% confidence interval, 2.57-13.0; 180-239 minutes: odds ratio, 8.01; 95% confidence interval, 3.54-18.10; and 240+ minutes: odds ratio, 17.4; 95% confidence interval, 7.88-38.37) were significantly associated with venous thromboembolism risk.

CONCLUSIONS

Venous thromboembolism is an uncommon complication of ventral hernia repair. It is associated with increased readmission, reoperation, and mortality rates. Larger defect width and operative time are most predictive of perioperative venous thromboembolism risk for patients undergoing ventral hernia repair.

Venous thromboembolism prophylaxis usage among surgical patients in both private and public hospitals in Ethiopia

Background

Venous thromboembolism (VTE) remains the commonest preventable cause of death in postoperative patients. VTE prophylaxis significantly reduces mortality risk, yet its utilization remains alarmingly low and variable (6-61 %) worldwide. This study aimed to compare VTE prophylaxis use among adult surgical patients in major hospitals in Addis Ababa, Ethiopia.

Materials and methods

A multicenter cross-sectional study was conducted in one private (Myungsung Christian Medical Center Comprehensive Specialized Hospital (MCM CSH)), and two public hospitals (Yekatit 12 Hospital Medical College and Menelik II Referral Hospital). Data was collected by chart review using standardized checklist. Caprini score was used for risk stratification, and associations was assessed using chi-square test with significance set at p < 0.05.

Results

From a total of 423 patients, 222 (52.3 %) patients were male. The mean age of the patients is 43.3(±14.7 SD) years. 414 (98 %) patients were at risk for VTE with 257(61 %) having moderate to high risk, but only 31(7.5 %) were on prophylaxis. Prophylaxis use was 12.5 % in MCM CSH, but it was 5.5 % and 5.1 % in Yekatit 12 and Menelik II Referral Hospitals respectively. VTE prophylaxis use was significantly less in public hospitals (p < 0.05).

Conclusions

Despite the majority of surgical patients being at risk of developing VTE, VTE prophylaxis remains significantly underutilized across major private and public hospitals in Ethiopia, particularly in public settings. The current study suggests standard risk assessment model implementation to address this significant and understudied risk to patients' lives.

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.

Risk of thrombosis and bleeding in gynecologic noncancer surgery: systematic review and meta-analysis

OBJECTIVE

This study aimed to provide procedure-specific estimates of the risk for symptomatic venous thromboembolism and major bleeding in noncancer gynecologic surgeries.

DATA SOURCES

We conducted comprehensive searches on Embase, MEDLINE, Web of Science, and Google Scholar. Furthermore, we performed separate searches for randomized trials that addressed the effects of thromboprophylaxis.

STUDY ELIGIBILITY CRITERIA

Eligible studies were observational studies that enrolled ≥50 adult patients who underwent noncancer gynecologic surgery procedures and that reported the absolute incidence of at least 1 of the following: symptomatic pulmonary embolism, symptomatic deep vein thrombosis, symptomatic venous thromboembolism, bleeding that required reintervention (including re-exploration and angioembolization), bleeding that led to transfusion, or postoperative hemoglobin level <70 g/L.

METHODS

A teams of 2 reviewers independently assessed eligibility, performed data extraction, and evaluated the risk of bias of the eligible articles. We adjusted the reported estimates for thromboprophylaxis and length of follow-up and used the median value from studies to determine the cumulative incidence at 4 weeks postsurgery stratified by patient venous thromboembolism risk factors and used the Grading of Recommendations Assessment, Development and Evaluation approach to rate the evidence certainty.

RESULTS

We included 131 studies (1,741,519 patients) that reported venous thromboembolism risk estimates for 50 gynecologic noncancer procedures and bleeding requiring reintervention estimates for 35 procedures. The evidence certainty was generally moderate or low for venous thromboembolism and low or very low for bleeding requiring reintervention. The risk for symptomatic venous thromboembolism varied from a median of <0.1% for several procedures (eg, transvaginal oocyte retrieval) to 1.5% for others (eg, minimally invasive sacrocolpopexy with hysterectomy, 1.2%-4.6% across patient venous thromboembolism risk groups). Venous thromboembolism risk was <0.5% for 30 (60%) of the procedures; 0.5% to 1.0% for 10 (20%) procedures; and >1.0% for 10 (20%) procedures. The risk for bleeding the require reintervention varied from <0.1% (transvaginal oocyte retrieval) to 4.0% (open myomectomy). The bleeding requiring reintervention risk was <0.5% in 17 (49%) procedures, 0.5% to 1.0% for 12 (34%) procedures, and >1.0% in 6 (17%) procedures.

CONCLUSION

The risk for venous thromboembolism in gynecologic noncancer surgery varied between procedures and patients. Venous thromboembolism risks exceeded the bleeding risks only among selected patients and procedures. Although most of the evidence is of low certainty, the results nevertheless provide a compelling rationale for restricting pharmacologic thromboprophylaxis to a minority of patients who undergo gynecologic noncancer procedures.

Systematic Reviews and Meta-analyses of the Procedure-specific Risks of Thrombosis and Bleeding in General Abdominal, Colorectal, Upper Gastrointestinal, and Hepatopancreatobiliary Surgery

OBJECTIVE

To provide procedure-specific estimates of symptomatic venous thromboembolism (VTE) and major bleeding after abdominal surgery.

BACKGROUND

The use of pharmacological thromboprophylaxis represents a trade-off that depends on VTE and bleeding risks that vary between procedures; their magnitude remains uncertain.

METHODS

We identified observational studies reporting procedure-specific risks of symptomatic VTE or major bleeding after abdominal surgery, adjusted the reported estimates for thromboprophylaxis and length of follow-up, and estimated cumulative incidence at 4 weeks postsurgery, stratified by VTE risk groups, and rated evidence certainty.

RESULTS

After eligibility screening, 285 studies (8,048,635 patients) reporting on 40 general abdominal, 36 colorectal, 15 upper gastrointestinal, and 24 hepatopancreatobiliary surgery procedures proved eligible. Evidence certainty proved generally moderate or low for VTE and low or very low for bleeding requiring reintervention. The risk of VTE varied substantially among procedures: in general abdominal surgery from a median of <0.1% in laparoscopic cholecystectomy to a median of 3.7% in open small bowel resection, in colorectal from 0.3% in minimally invasive sigmoid colectomy to 10.0% in emergency open total proctocolectomy, and in upper gastrointestinal/hepatopancreatobiliary from 0.2% in laparoscopic sleeve gastrectomy to 6.8% in open distal pancreatectomy for cancer.

CONCLUSIONS

VTE thromboprophylaxis provides net benefit through VTE reduction with a small increase in bleeding in some procedures (eg, open colectomy and open pancreaticoduodenectomy), whereas the opposite is true in others (eg, laparoscopic cholecystectomy and elective groin hernia repairs). In many procedures, thromboembolism and bleeding risks are similar, and decisions depend on individual risk prediction and values and preferences regarding VTE and bleeding.

The Benefits and Imperative of Venous Thromboembolism Risk Screening for Hospitalized Patients: A Systematic Review

Venous thromboembolism (VTE) is a major preventable condition in hospitalized patients globally. This systematic review evaluates the effectiveness and clinical significance of venous thromboembolism (VTE) risk-screening protocols in preventing VTE events among hospitalized patients. Databases, including PubMed, Embase and Cochrane, were searched without date limits for studies comparing outcomes between hospitalized patients who did and did not receive VTE risk screening using standard tools. Twelve studies, enrolling over 139,420 patients, were included. Study quality was assessed using the ROBVIS tool. The results were summarized narratively. The findings show significant benefits of using VTE risk screening versus usual care across various outcomes. Using recommended tools, like Caprini, Padua and IMPROVE, allowed for the accurate identification of high-risk patients who benefited most from prevention. Formal screening was linked to much lower VTE rates, shorter hospital stays, fewer deaths and better use of preventive strategies matched to estimated clot risk. This review calls for the widespread adoption of VTE risk screening as an important safety step for at-risk hospital patients. More high-quality comparative research is needed to validate screening tools in different settings and populations. In summary, VTE risk screening is essential for healthcare systems to reduce life-threatening VTE events and improve patient outcomes through properly targeted preventive methods.

Can Risk-Based Thromboprophylaxis Practice Guidelines be Safely Used in Esophagectomy Cases? Experience of an Academic Health System

BACKGROUND

Venous thromboembolism (VTE) occurs in 3-11% of esophagectomy patients and is associated with increased mortality and morbidity. The use of validated VTE risk assessment tools and compliance with recommended practice guidelines remains unclear. In this study, we seek to determine the use of Caprini guideline indicated VTE prophylaxis and its effect on VTE and bleeding complications following esophagectomy.

METHODS

Esophagectomy cases were identified from the Mayo Clinic electronic health records. Caprini score and VTE prophylaxis regimen received were determined retrospectively. VTE prophylaxis was identified as appropriate or inappropriate based on the Caprini score and prophylaxis received preoperative, during hospitalization, and after hospital discharge. Study cohorts were compared by Pearson Chi-square test, Fisher's Exact test, Kruskal-Wallis test, and logistic regression models. Stata/MP 16.1 was used for analysis. Odds ratios and 95% confidence intervals were reported for logistic regression models. A p-value < 0.05 was considered significant.

RESULTS

Four hundred and fifty-six esophagectomy cases were analyzed. The median Caprini score was thirteen. Appropriate prophylaxis resulted in a 6.9-fold reduction in inpatient VTE. All 30- and 90-day post-discharge VTEs occurred in those not receiving Caprini guideline-indicated VTE prophylaxis. Inpatient, 30- and 90-day post-discharge bleeding rates were 7.68%, 0.91%, and 2.11%, respectively; however, bleeding was not increased with receipt of appropriate prophylaxis.

CONCLUSION

In this esophagectomy cohort, Caprini guideline indicated VTE prophylaxis resulted in reduced inpatient VTE events without increasing bleeding complications. Risk-based VTE prevention measures should be considered in this patient cohort known to be at heightened risk for postoperative VTE.

Venous thromboembolism (VTE) prophylaxis after bariatric surgery: a national survey of MBSAQIP director practices

BACKGROUND

Venous thromboembolism (VTE) is the most common cause of death following metabolic/bariatric surgery (MBS), with most events occurring after discharge. The available evidence on ideal prophylaxis type, dosage, and duration after discharge is limited.

OBJECTIVES

Assess metabolic/bariatric surgeon VTE prophylaxis practices and define existing variability.

SETTING

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP)-accredited centers.

METHODS

The members of the ASMBS Research Committee developed and administered a web-based survey to MBSAQIP medical directors and ASMBS members to examine the differences in clinical practice regarding the administration of VTE prophylaxis after MBS.

RESULTS

Overall, 264 metabolic/bariatric surgeons (136 medical directors and 128 ASMBS members) participated in the survey. Both mechanical and chemical VTE prophylaxis was used by 97.1% of the participants, knee-high compression devices by 84.7%, enoxaparin (32.4% 40 mg every 24 hours, 22.7% 40 mg every 12 hours, 24.4% adjusted the dose based on body mass index) by 56.5%, and heparin (46.1% 5000 units every 8 hours, 22.6% 5000 units every 12 hours, 20.9% 5000 units once preoperatively) by 38.1%. Most surgeons (81.6%) administered the first dose preoperatively, while the first postoperative dose was given on the evening of surgery by 44% or the next morning by 42.2%. Extended VTE prophylaxis was prescribed for 2 weeks by 38.7% and 4 weeks by 28.9%.

CONCLUSIONS

VTE prophylaxis practices vary widely among metabolic/bariatric surgeons. Variability may be related to limited available comparative evidence. Large prospective clinical trials are needed to define optimal practices for VTE risk stratification and prophylaxis in bariatric surgery patients.

Association of Prophylaxis and Length of Stay With Venous Thromboembolism in Abdominopelvic Surgery

INTRODUCTION

Extended venous thromboembolism prophylaxis (eVTEp) is recommended for select patients who have undergone major abdominopelvic surgery to prevent postdischarge venous thromboembolism (pdVTE). Criteria for selection of these patients are untested for this purpose and may be ineffective. To address this gap, we investigated the effectiveness of eVTEp on pdVTE rates.

METHODS

A retrospective cohort study of patients undergoing abdominopelvic surgery from January 2016 to February 2020 was performed using data from the Michigan Surgical Quality Collaborative. pdVTE was the main outcome. Our exposure variable, eVTEp, was compared dichotomously. Length of stay (LOS) was compared categorically using clinically relevant groups. Age, race, cancer occurrence, inflammatory bowel disease, surgical approach, and surgical time were covariates among other variables. Descriptive statistics, propensity score matching, and multivariable logistic regression were performed to compare pdVTE rates.

RESULTS

A total of 45,637 patients underwent abdominopelvic surgery. Of which, 3063 (6.71%) were prescribed eVTEp. Two hundred eighty-five (0.62%) had pdVTE. Of the 285, 59 (21%) patients received eVTEp, while 226 (79%) patients did not. After propensity score matching, multivariable logistic regression analysis showed pdVTE was associated with eVTEp and LOS of 5 d or more (P < 0.001). eVTEp was not associated with LOS. Further analysis showed increased risk of pdVTE with increasing LOS independent of prescription of eVTEp based on known risk factors.

CONCLUSIONS

pdVTE was associated with increasing LOS but not with other VTE risk factors after propensity score matching. Current guidelines for eVTEp do not include LOS. Our findings suggest that LOS >5 d should be added to the criteria for eVTEp.

A retrospective analysis based on multiple machine learning models to predict lymph node metastasis in early gastric cancer

Background

Endoscopic submucosal dissection has become the primary option of treatment for early gastric cancer. However, lymph node metastasis may lead to poor prognosis. We analyzed factors related to lymph node metastasis in EGC patients, and we developed a construction prediction model with machine learning using data from a retrospective series.

Methods

Two independent cohorts’ series were evaluated including 305 patients with EGC from China as cohort I and 35 patients from Spain as cohort II. Five classifiers obtained from machine learning were selected to establish a robust prediction model for lymph node metastasis in EGC.

Results

The clinical variables such as invasion depth, histologic type, ulceration, tumor location, tumor size, Lauren classification, and age were selected to establish the five prediction models: linear support vector classifier (Linear SVC), logistic regression model, extreme gradient boosting model (XGBoost), light gradient boosting machine model (LightGBM), and Gaussian process classification model. Interestingly, all prediction models of cohort I showed accuracy between 70 and 81%. Furthermore, the prediction models of the cohort II exhibited accuracy between 48 and 82%. The areas under curve (AUC) of the five models between cohort I and cohort II were between 0.736 and 0.830.

Conclusions

Our results support that the machine learning method could be used to predict lymph node metastasis in early gastric cancer and perhaps provide another evaluation method to choose the suited treatment for patients.

Deep Venous Thrombosis

Venous thromboembolism (VTE) is the third most common cardiovascular disorder, affecting up to 5% of the population. VTE commonly manifests as lower-extremity deep venous thrombosis (DVT) or pulmonary embolism. Half of these events are associated with a transient risk factor and may be preventable with prophylaxis. Direct oral anticoagulants are effective and safe and carry a lower risk for bleeding than vitamin K antagonists. Many patients with VTE will have a chronic disease requiring long-term anticoagulation. Postthrombotic syndrome affects 25% to 40% of patients with DVT and significantly impacts function and quality of life.

Simultaneous versus staged bilateral total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Total hip arthroplasty is a common orthopedic surgery for treating primary or secondary hip osteoarthritis. Bilateral total hip replacement could be performed in a single stage or two separate stages. Each surgical procedure's reliability, safety, and complications have been reported controversially. This study aimed to review the current evidence regarding the outcomes of simultaneous and staged bilateral total hip arthroplasty.

METHODS

We conducted a meta-analysis using MEDLINE, EMBASE, Web of Science, and Scopus databases. Eligible studies compared complications and related outcomes between simultaneous and staged bilateral THA. Two reviewers independently screened initial search results, assessed methodological quality, and extracted data. We used the Mantel-Haenszel method to perform the meta-analysis.

RESULTS

In our study, we included 29,551 patients undergoing simBTHA and 74,600 patients undergoing stgBTHA. In favor of the simBTHA, a significant reduction in deep vein thrombosis (DVT) and systemic, local, and pulmonary complications was documented. However, we evidenced an increased pulmonary embolism (PE) and periprosthetic fracture risk in simBTHA. In the simBTHA, total blood loss, length of hospital stay, and total cost were lower.

CONCLUSION

This meta-analysis shows that simultaneous bilateral THA accompanies fewer complications and lower total cost. Well-designed randomized controlled trials are needed to provide robust evidence.

Extended-duration thromboprophylaxis after ventral hernia repair: a risk model to predict venous thrombotic events after hospital discharge

BACKGROUND

Venous thromboembolism (VTE) is a major source of morbidity and mortality after ventral hernia surgery, but the risk of VTE after discharge has not been reported.

STUDY DESIGN

Data from the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) were used to investigate the risk of post-discharge VTE. Current procedural terminology (CPT) codes identified all reported patients who underwent ventral hernia repair from 2011 to 2017. We created a multivariable regression model for post-discharge VTE, using the 2011-2016 dataset to develop the model and 2017 as a validation set. The prediction model was used to create a risk calculator as a mobile application.

RESULTS

The rate of VTE after surgery was 0.62% (878 of 141,065) with 48% occurring after discharge from the hospital. The final predictor model consisted of eight variables: age > 60 years, male sex, body mass index (BMI) ≥ 35 kg/m2), operative time > 2 h, concurrent panniculectomy, post-operative hospitalization > 1 day, presence of bleeding disorder, and emergency operation. The model had good calibration and discrimination (Hosmer-Lemeshow goodness-of-fit test, p = 0.71; c-statistic = 0.71). Threshold analysis showed a strategy of extended-duration thromboprophylaxis was optimized when the risk of post-discharge VTE was > 0.3%.

CONCLUSION

Forty-eight percent of VTEs after ventral hernia repair occur after discharge, particularly in older, male, obese patients undergoing longer and complex operations that require hospitalization > 1 day. Post-discharge thromboprophylaxis should be considered in these patients, particularly when risk of VTE exceeds 0.3%.

Factors Affecting the Decision to Initiate Anticoagulation After Spine Surgery: Findings From the AOSpine Anticoagulation Global Initiative

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

To identify factors influencing pharmacologic anticoagulation initiation after spine surgery based on the AOSpine Anticoagulation Global Survey.

METHODS

This survey was distributed to the international membership of AOSpine (n = 3805). A Likert-type scale described grade practice-specific factors on a scale from low (1) to high (5) importance, and patient-specific factors a scale from low (0) to high (3) importance. Analysis was performed to determine which factors were significant in the decision making surrounding the initiation of pharmacologic anticoagulation.

RESULTS

A total of 316 spine surgeons from 64 countries completed the survey. In terms of practice-specific factors considered to initiate treatment, expert opinion was graded the highest (mean grade ± SD = 3.2 ± 1.3), followed by fellowship training (3.2 ± 1.3). Conversely, previous studies (2.7 ± 1.2) and unspecified guidelines were considered least important (2.6 ± 1.6). Patient body mass index (2.0 ± 1.0) and postoperative mobilization (2.3 ± 1.0) were deemed most important and graded highly overall. Those who rated estimated blood loss with greater importance in anticoagulation initiation decision making were more likely to administer thromboprophylaxis at later times (hazard ratio [HR] = 0.68-0.71), while those who rated drain output with greater importance were likely to administer thromboprophylaxis at earlier times (HR = 1.32-1.43).

CONCLUSION

Among our global cohort of spine surgeons, certain patient factors (ie, patient mobilization and body mass index) and practice-specific factors (ie, expert opinion and fellowship training) were considered to be most important when considering anticoagulation start times.

Do Cost Limitations of Extended Prophylaxis After Surgery Apply to Ulcerative Colitis Patients?

BACKGROUND

Colorectal surgery patients with ulcerative colitis are at increased risk of postoperative venous thromboembolism. Extended prophylaxis for thromboembolism prevention has been used in colorectal surgery patients, but it has been criticized for its lack of cost-effectiveness. However, the cost-effectiveness of extended prophylaxis for postoperative ulcerative colitis patients may be unique.

OBJECTIVE

This study aimed to assess the cost-effectiveness of extended prophylaxis in postoperative ulcerative colitis patients.

DESIGN

A decision analysis compared costs and benefits in postoperative ulcerative colitis patients with and without extended prophylaxis over a lifetime horizon.

SETTING

Assumptions for decision analysis were identified from available literature for a typical ulcerative colitis patient's risk of thrombosis, age at surgery, type of thrombosis, prophylaxis risk reduction, bleeding complications, and mortality.

MAIN OUTCOME MEASURES

Costs ($) and benefits (quality-adjusted life year) reflected a societal perspective and were time-discounted at 3%. Costs and benefits were combined to produce the main outcome measure, the incremental cost-effectiveness ratio ($ per quality-adjusted life year). Multivariable probabilistic sensitivity analysis modeled uncertainty in probabilities, costs, and disutilities.

RESULTS

Using reference parameters, the individual expected societal total cost of care was $957 without and $1775 with prophylaxis (not cost-effective; $257,280 per quality-adjusted life year). Preventing a single mortality with prophylaxis would cost $5 million (number needed to treat: 6134 individuals). Adjusting across a range of scenarios upheld these conclusions 77% of the time. With further sensitivity testing, venous thromboembolism cumulative risk (>1.5%) and ePpx regimen pricing (<$299) were the 2 parameters most sensitive to uncertainty.

LIMITATIONS

Recommendations of decision analysis methodology are limited to group decision-making, not an individual risk profile.

CONCLUSION

Routine ePpx in postoperative ulcerative colitis patients is not cost-effective. This finding is sensitive to higher-than-average rates of venous thromboembolism and low-cost prophylaxis opportunities. See Video Abstract at http://links.lww.com/DCR/B818.

SE APLICAN LAS LIMITACIONES DE COSTOS DE LA PROFILAXIS PROLONGADA DESPUS DE LA CIRUGA A LOS PACIENTES CON COLITIS ULCEROSA

ANTECEDENTES:Los pacientes de cirugía colorrectal con colitis ulcerosa tienen un mayor riesgo de tromboembolismo venoso posoperatorio. La profilaxis extendida para la prevención de la tromboembolia se ha utilizado en pacientes con cirugía colorrectal, aunque ha sido criticada por su falta de rentabilidad. Sin embargo, la rentabilidad de la profilaxis prolongada para los pacientes posoperados con colitis ulcerosa puede ser aceptable.OBJETIVO:Evaluar la rentabilidad de la profilaxis prolongada en pacientes posoperados con colitis ulcerosa.DISEÑO:Un análisis de decisiones comparó los costos y beneficios en pacientes posoperados con colitis ulcerosa con y sin profilaxis prolongada de por vida.AJUSTE:Los supuestos para el análisis de decisiones se identificaron a partir de la literatura disponible para el riesgo de trombosis de un paciente con colitis ulcerosa típica, la edad al momento de la cirugía, el tipo de trombosis, la reducción del riesgo con profilaxis, las complicaciones hemorrágicas y la mortalidad.PRINCIPALES MEDIDAS DE RESULTADO:Los costos ($) y los beneficios (año de vida ajustado por calidad) reflejaron una perspectiva social y se descontaron en el tiempo al 3%. Los costos y los beneficios se combinaron para producir la principal medida de resultado, la relación costo-efectividad incremental ($ por año de vida ajustado por calidad). El análisis de sensibilidad probabilística multivariable modeló la incertidumbre en probabilidades, costos y desutilidades.RESULTADOS:Utilizando parámetros de referencia, el costo total de atención social esperado individual fue de $957 sin profilaxis y $1775 con profilaxis (no rentable; $257,280 por año de vida ajustado por calidad). La prevención de una sola mortalidad con profilaxis costaría $5.0 millones (número necesario a tratar: 6.134 personas). El ajuste en una variedad de escenarios mantuvo estas conclusiones el 77% de las veces. Con más pruebas de sensibilidad, el riesgo acumulado de TEV (>1,5%) y el precio del régimen de ePpx (<$299) fueron los dos parámetros más sensibles a la incertidumbre.LIMITACIONES:Las recomendaciones de la metodología de análisis de decisiones se limitan a la toma de decisiones en grupo, no a un perfil de riesgo individual.CONCLUSIÓN:La profilaxis extendida de rutina en pacientes posoperados con colitis ulcerosa no es rentable. Este hallazgo es sensible a tasas de TEV superiores al promedio y oportunidades de profilaxis de bajo costo. Consulted Video Resumen en http://links.lww.com/DCR/B818. (Traducción-Dr. Felipe Bellolio).

The Safety and Efficacy of Apixaban (Eliquis) in 5017 Post-bariatric Patients with 95.3% Follow-up: a Multicenter Study

BACKGROUND

Thromboprophylaxis in bariatric surgery is widely debated; however, few large articles evaluate treatment plans and their efficacy. Herein, we make the first large-scale report of the safety and efficacy of apixaban (Eliquis) for thrombus prevention following bariatric surgery.

PURPOSE

To evaluate the safety and efficacy of apixaban following bariatric surgery.

SETTING

Three private institutes, USA.

MATERIALS AND METHODS

Data from 5017 consecutive bariatric patients that were placed on postoperative apixaban for thromboprophylaxis were used for retrospective analysis. The dose prescribed to patients was 2.5 mg PO BID for a total of 30 days starting on day 3 postoperatively.

RESULTS

In total, of the 5017 patients, 59.7%, 31.2%, 4.4%, 2.5%, 1.8%, and 0.1% of the patients had undergone sleeve gastrectomy (SG), single-anastomosis duodeno-ileal bypass with SG (SADI-S), Roux-en-Y gastric bypass (RYGB), conversion from SG to SADI, small bowel reconstruction, and RYGB reversal, respectively. The 30-day follow-up rate was 95.3%. In total, 1.7% of patients experienced apixaban-related side effects. The most common side effects were menorrhagia and rash. Two (0.03%) side effects developed into Clavien-Dindo grade II complications. Overall, 10 (0.1%) patients experienced thromboembolic complications (five (0.09%) PVTs and five (0.09%) PEs). In each case, the protocol was not followed for extenuating circumstances. There were no deaths or thromboembolic events in cases where the protocol was able to be fully followed.

CONCLUSIONS

In conclusion, 30 days of postoperative apixaban appears to be safe and effective with minimal side effects while preventing thromboembolic events.

Systematic reviews of observational studies of Risk of Thrombosis and Bleeding in General and Gynecologic Surgery (ROTBIGGS): introduction and methodology

BACKGROUND

Venous thromboembolism (VTE) and bleeding are serious and potentially fatal complications of surgical procedures. Pharmacological thromboprophylaxis decreases the risk of VTE but increases the risk of major post-operative bleeding. The decision to use pharmacologic prophylaxis therefore represents a trade-off that critically depends on the incidence of VTE and bleeding in the absence of prophylaxis. These baseline risks vary widely between procedures, but their magnitude is uncertain. Systematic reviews addressing baseline risks are scarce, needed, and require innovations in methodology. Indeed, systematic summaries of these baseline risk estimates exist neither in general nor gynecologic surgery. We will fill this knowledge gap by performing a series of systematic reviews and meta-analyses of the procedure-specific and patient risk factor stratified risk estimates in general and gynecologic surgeries.

METHODS

We will perform comprehensive literature searches for observational studies in general and gynecologic surgery reporting symptomatic VTE or bleeding estimates. Pairs of methodologically trained reviewers will independently assess the studies for eligibility, evaluate the risk of bias by using an instrument developed for this review, and extract data. We will perform meta-analyses and modeling studies to adjust the reported risk estimates for the use of thromboprophylaxis and length of follow up. We will derive the estimates of risk from the median estimates of studies rated at the lowest risk of bias. The primary outcomes are the risk estimates of symptomatic VTE and major bleeding at 4 weeks post-operatively for each procedure stratified by patient risk factors. We will apply the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate evidence certainty.

DISCUSSION

This series of systematic reviews, modeling studies, and meta-analyses will inform clinicians and patients regarding the trade-off between VTE prevention and bleeding in general and gynecologic surgeries. Our work advances the standards in systematic reviews of surgical complications, including assessment of risk of bias, criteria for arriving at the best estimates of risk (including modeling of the timing of events and dealing with suboptimal data reporting), dealing with subgroups at higher and lower risk of bias, and use of the GRADE approach.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021234119.

Risk assessment models for venous thromboembolism in hospitalised adult patients: a systematic review

INTRODUCTION

Hospital-acquired thrombosis accounts for a large proportion of all venous thromboembolism (VTE), with significant morbidity and mortality. This subset of VTE can be reduced through accurate risk assessment and tailored pharmacological thromboprophylaxis. This systematic review aimed to determine the comparative accuracy of risk assessment models (RAMs) for predicting VTE in patients admitted to hospital.

METHODS

A systematic search was performed across five electronic databases (including MEDLINE, EMBASE and the Cochrane Library) from inception to February 2021. All primary validation studies were eligible if they examined the accuracy of a multivariable RAM (or scoring system) for predicting the risk of developing VTE in hospitalised inpatients. Two or more reviewers independently undertook study selection, data extraction and risk of bias assessments using the PROBAST (Prediction model Risk Of Bias ASsessment Tool) tool. We used narrative synthesis to summarise the findings.

RESULTS

Among 6355 records, we included 51 studies, comprising 24 unique validated RAMs. The majority of studies included hospital inpatients who required medical care (21 studies), were undergoing surgery (15 studies) or receiving care for trauma (4 studies). The most widely evaluated RAMs were the Caprini RAM (22 studies), Padua prediction score (16 studies), IMPROVE models (8 studies), the Geneva risk score (4 studies) and the Kucher score (4 studies). C-statistics varied markedly between studies and between models, with no one RAM performing obviously better than other models. Across all models, C-statistics were often weak (<0.7), sometimes good (0.7-0.8) and a few were excellent (>0.8). Similarly, estimates for sensitivity and specificity were highly variable. Sensitivity estimates ranged from 12.0% to 100% and specificity estimates ranged from 7.2% to 100%.

CONCLUSION

Available data suggest that RAMs have generally weak predictive accuracy for VTE. There is insufficient evidence and too much heterogeneity to recommend the use of any particular RAM.

PROSPERO REGISTRATION NUMBER

Steve Goodacre, Abdullah Pandor, Katie Sworn, Daniel Horner, Mark Clowes. A systematic review of venous thromboembolism RAMs for hospital inpatients. PROSPERO 2020 CRD42020165778. Available from https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=165778https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=165778.

Hemostatic factors, inflammatory markers, and risk of incident venous thromboembolism: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Several hemostatic factors and inflammatory markers are associated with the risk of incident venous thromboembolism (VTE), however, most existing data are from case-control studies in Caucasian populations.

OBJECTIVES

We aimed to prospectively confirm previous findings and explore less studied biomarkers in relation to VTE risk in a multi-racial/multi-ethnic cohort.

METHODS

Circulating levels of factor VIII, fibrinogen, D-dimer, plasmin-antiplasmin complex (PAP), C-reactive protein (CRP), and interleukin-6 (IL-6) were measured at baseline (2000-2002) in 6706 participants of the Multi-Ethnic Study of Atherosclerosis. Incident VTE was identified using hospitalization discharge codes from baseline to December 31, 2015. Hazard ratios (HRs) of VTE were estimated in Cox regression models.

RESULTS

There were 227 events during a median of 14 years of follow-up. Compared with participants in the lowest quartile, the HRs for those above the 95th percentile and p for trend across categories were 3.50 (95% confidence interval [CI] 1.98-6.19; p < .001) for D-dimer, 1.49 (95% CI 0.84-2.63; p = .02) for factor VIII, 1.32 (95% CI 0.76-2.28; p = .99) for fibrinogen, 1.92 (95% CI 1.08-3.42; p = .15) for PAP, 1.68 (95% CI 0.81-3.48; p = .08) for CRP, and 2.55 (95% CI 1.15-5.66; p = .07) for IL-6, after adjustment for demographics and body mass index. For CRP and IL-6, follow-up was restricted to 10 years because of violations of the proportional hazards assumption. No significant interactions by age/ethnicity were observed.

CONCLUSIONS

We demonstrated a fairly novel association between PAP and risk of incident VTE, and contributed further prospective confirmation regarding the associations of D-dimer, factor VIII, and IL-6 with VTE.

Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association

Venous thromboembolism (VTE) is a major preventable disease that affects hospitalized inpatients. Risk stratification and prophylactic measures have good evidence supporting their use, but multiple reasons exist that prevent full adoption, compliance, and efficacy that may underlie the persistence of VTE over the past several decades. This policy statement provides a focused review of VTE, risk scoring systems, prophylaxis, and tracking methods. From this summary, 5 major areas of policy guidance are presented that the American Heart Association believes will lead to better implementation, tracking, and prevention of VTE events. They include performing VTE risk assessment and reporting the level of VTE risk in all hospitalized patients, integrating preventable VTE as a benchmark for hospital comparison and pay-for-performance programs, supporting appropriations to improve public awareness of VTE, tracking VTE nationwide with the use of standardized definitions, and developing a centralized data steward for data tracking on VTE risk assessment, prophylaxis, and rates.

Low molecular weight heparin versus unfractioned heparin for anticoagulation during perioperative extracorporeal membrane oxygenation: A single center experience in 102 lung transplant patients

Extracorporeal membrane oxygenation (ECMO) is gaining importance in the perioperative management of lung transplant patients. To date, the ideal substance for anticoagulation of ECMO patients is still a matter of debate. In this study, we describe our experience with the use of low molecular weight heparin (LMWH) in comparison with unfractioned heparin (UFH) in lung transplant patients undergoing perioperative ECMO support. We retrospectively analyzed data from all lung transplant patients who underwent perioperative ECMO support at our institution between 2013 and 2017. Bleeding events served as primary outcome parameter. Secondary outcome parameters consisted of thromboembolic events. 102 patients were included in this study, of which 22 (21.6%) received UFH for anticoagulation, and 80 (78.4%) received LMWH. There was no difference between the two groups in regard to serious bleeding events (22.7% in the UFH group vs 12.5% in the LMWH group, P = .31). However, the proportion of patients experiencing thromboembolic events was significantly higher in the UFH group than in the LMWH group (50% vs 20%, P = .01). After adjusting for baseline differences between the two groups, we still observed a difference with respect to thromboembolic events. These data remain to be validated in future prospective, randomized trials.

A risk-scoring system to predict clinical failure for patients with achalasia after peroral endoscopic myotomy

BACKGROUND AND AIMS

We aimed to establish a predictive model and develop a simple risk-scoring system (Zhongshan POEM Score) to help clinicians to characterize high-risk patients for clinical failure after peroral endoscopic myotomy (POEM).

METHODS

A total of 1538 patients with achalasia treated with POEM with available follow-up data were included in this study and were randomly classified to the training cohort (n = 769) or internal validation cohort (n = 769). A risk-scoring system was developed using multivariate Cox regression analysis in the training cohort. The system was then internally validated by survival analysis in the validation cohort.

RESULTS

During a median follow-up time of 42 months, 109 patients had clinical failure. In the training stage, 3 risk factors for clinical failure were weighted with point values: previous treatment (2 points), intraprocedural mucosal injury (2 points for type I and 6 points for type II), and clinical reflux (3 points). The patients were categorized into low-risk and high-risk groups. In the validation stage, Kaplan-Meier curves differed significantly between the 2 groups. Patients in the high-risk group had a significantly higher risk of clinical failure than those in the low-risk group (hazard ratio, 3.99; 95% confidence interval, 2.31-6.91; P < .001). Satisfactory discrimination and calibration were shown.

CONCLUSIONS

This risk-scoring system demonstrated good performance in predicting clinical failure in patients who underwent POEM.

Incidence of Venous Thromboembolism Following Major Emergency Abdominal Surgery

BACKGROUND

In a retrospective cohort study, we looked at the incidence and risk factors of developing in-hospital venous thromboembolism (VTE) after major emergency abdominal surgery and the risk factors for developing a venous thrombosis.

METHODS

Data were extracted through medical records from all patients undergoing major emergency abdominal surgery at a Danish University Hospital from 2010 until 2016. The primary outcome was the incidence of venous thrombosis developed in the time from surgery until discharge from hospital. The secondary outcomes were 30-day mortality and postoperative complications. Multivariate logistic analyses were used for confounder control.

RESULTS

In total, 1179 patients who underwent major emergency abdominal surgery during 2010-2016 were included. Thirteen patients developed a postoperative venous thromboembolism (1.1%) while hospitalized. Eight patients developed a pulmonary embolism all verified by CT scan and five patients developed a deep venous thrombosis verified by ultrasound scan. Patients diagnosed with a VTE were significantly longer in hospital with a length of stay of 34 versus 14 days, P < 0.001, and they suffered significantly more surgical complications (69.2% vs. 30.4%, P = 0.007). Thirty-day mortality was equal in patients with and without a venous thrombosis. In a multivariate analysis adjusting for gender, ASA group, BMI, type of surgery, dalteparin dose and treatment with anticoagulants, we found that a dalteparin dose ≥5000 IU was associated with the risk of postoperative surgical complications (odds ratio 1.55, 95% CI 1.11-2.16, P = 0.009).

CONCLUSION

In this study, we found a low incidence of venous thrombosis among patients undergoing major emergency abdominal surgery, comparable to the incidence after elective surgery.

Venous Thromboembolism Prophylaxis Strategies for People Undergoing Elective Total Hip Replacement: A Systematic Review and Network Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of venous thromboembolism prophylaxis in people undergoing elective total hip replacement.

METHODS

Systematic review and Bayesian network meta-analyses of randomized controlled trials were conducted for 3 outcomes: deep vein thrombosis (DVT), pulmonary embolism (PE), and major bleeding (MB). MEDLINE, EMBASE, and Cochrane Library (CENTRAL) databases were searched. Study quality was assessed using the Cochrane risk-of-bias checklist. Fixed- and random-effects models were fitted and compared. The median relative risk (RR) and odds ratio (OR) compared with no prophylaxis, with their 95% credible intervals (CrIs), rank, and probability of being the best, were calculated.

RESULTS

Forty-two (n = 24 374, 26 interventions), 30 (n = 28 842, 23 interventions), and 24 (n = 31 792, 15 interventions) randomized controlled trials were included in the DVT, PE, and MB networks, respectively. Rivaroxaban had the highest probability of being the most effective intervention for DVT (RR 0.06 [95% CrI 0.01-0.29]). Strategy of low-molecular-weight heparin followed by aspirin had the highest probability of reducing the risk of PE and MB (RR 0.0011 [95% CrI 0.00-0.096] and OR 0.37 [95% CrI 0.00-26.96], respectively). The ranking of efficacy estimates across the 3 networks, particularly PE and MB, had very wide CrIs, indicating high degree of uncertainty.

CONCLUSIONS

A strategy of low-molecular-weight heparin given for 10 days followed by aspirin for 28 days had the best benefit-risk balance, with the highest probability of being the best on the basis of the results of the PE and MB network meta-analyses. Nevertheless, there is considerable uncertainty around the median ranks of the interventions.

Untapped potential of multicenter studies: a review of cardiovascular risk prediction models revealed inappropriate analyses and wide variation in reporting

BACKGROUND

Clinical prediction models are often constructed using multicenter databases. Such a data structure poses additional challenges for statistical analysis (clustered data) but offers opportunities for model generalizability to a broad range of centers. The purpose of this study was to describe properties, analysis, and reporting of multicenter studies in the Tufts PACE Clinical Prediction Model Registry and to illustrate consequences of common design and analyses choices.

METHODS

Fifty randomly selected studies that are included in the Tufts registry as multicenter and published after 2000 underwent full-text screening. Simulated examples illustrate some key concepts relevant to multicenter prediction research.

RESULTS

Multicenter studies differed widely in the number of participating centers (range 2 to 5473). Thirty-nine of 50 studies ignored the multicenter nature of data in the statistical analysis. In the others, clustering was resolved by developing the model on only one center, using mixed effects or stratified regression, or by using center-level characteristics as predictors. Twenty-three of 50 studies did not describe the clinical settings or type of centers from which data was obtained. Four of 50 studies discussed neither generalizability nor external validity of the developed model.

CONCLUSIONS

Regression methods and validation strategies tailored to multicenter studies are underutilized. Reporting on generalizability and potential external validity of the model lacks transparency. Hence, multicenter prediction research has untapped potential.

REGISTRATION

This review was not registered.

Incidence Rates of Postoperative Pulmonary Embolisms in Symptomatic and Asymptomatic Patients, Detected by Diagnostic Images - A Single-Center Retrospective Study

BACKGROUND

Pulmonary embolism (PE) is a serious complication during the perioperative period. However, because most previous studies on the incidence of postoperative PE are based on symptoms, asymptomatic occurrences of PE have been overlooked, and the absolute incidence of postoperative PE remains unknown. The aim of this study was to investigate the incidence of perioperative PE, regardless of its symptoms, by reviewing the clinical interpretations of the diagnostic images obtained during the postoperative period.

METHODS AND RESULTS

This study included all patients aged at least 18 years who underwent operations under general and/or neuraxial anesthesia in our institution from 2013 to 2016. We reviewed all interpretations of the diagnostic imaging performed in the postoperative period. We analyzed the 90-day cumulative incidence of postoperative PE and the characteristics, risk factors, and symptoms of patients with and without postoperative PE. Among 21,763 operations, postoperative diagnostic imaging was performed in 1,168 patients, which found PE in 217 patients. Symptoms appeared in 11.1% (24/217) of the PE patients, and 66.7% of these symptoms were decreased levels of SpO2alone. Mortality from PE was 0.5% (1/217).

CONCLUSIONS

Diagnostic imaging found a number of postoperative PE cases, regardless of the presence of symptoms. Although symptomatic PE was not a frequent occurrence, these findings suggest that clinicians should be aware of postoperative PE even under current prophylaxis.

Clinical Outcomes of a Preoperative Inferior Vena Cava Filter in Acute Venous Thromboembolism Patients Undergoing Abdominal-Pelvic Cancer or Orthopedic Surgery

Purpose

Surgery is the most common risk factor for pulmonary embolism (PE) in patients with a recent venous thromboembolism (VTE). This study reviewed clinical outcomes of preoperative inferior vena cava filter (IVCF) use in patients with acute VTE during abdominal-pelvic cancer or lower extremity orthopedic surgeries.

Materials and Methods

We retrospectively analyzed 122 patients with a recent VTE who underwent IVCF replacement prior to abdominal-pelvic cancer or lower extremity orthopedic surgery conducted between January 2010 and December 2016. Demographics, clinical characteristics, postoperative IVCF status, risk factors for a captured thrombus, and clinical outcomes were collected for these subjects.

Results

Among the 122 study patients who were diagnosed with acute VTE in the prior 3 months and underwent preoperative IVCF replacement, 70 patients (57.4%) received abdominal-pelvic cancer surgery and 52 (42.6%) underwent lower extremity orthopedic surgery. There were no perioperative complications associated with IVCF in the study population and no cases of symptomatic PE postoperatively. A captured thrombus in the filter was identified postoperatively in 16 patients (13.1%). Logistic regression analysis indicated that postoperative anticoagulation within 48 hours significantly reduced the risk of a captured thrombus (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.08–0.94; P=0.032).

Conclusion

A captured thrombus in preoperative IVCF was identified postoperatively in 16 patients (13.1%). Postoperative anticoagulation within 48 hours reduces the risk of captured thrombus in these cases.

Mandatory Risk Assessment Reduces Venous Thromboembolism in Bariatric Surgery Patients

INTRODUCTION

Bariatric surgery patients are at high risk for venous thromboembolism (VTE), and chemoprophylaxis is recommended.

METHODS

Sheikh Khalifa Medical City (SKMC) is an American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) member since 2009. We report the rates of VTE in bariatric surgery patients from 2010 to 2016 compared to ACS NSQIP bariatric surgery programs before and after switching from heparin to low molecular weight heparin (LMWH), initiating mandatory risk assessment using Caprini scoring for VTE and adopting an aggressive strategy for high-risk patients regarding dosage of LMWH and chemoprophylaxis after discharge.

RESULTS

During the study period, there were 1152 cases (laparoscopic Roux-en-Y gastric bypass (LRYGB) 625 and laparoscopic sleeve gastrectomy (LSG) 527) at Bariatric & Metabolic Institute (BMI) Abu Dhabi compared to 65,693 cases (LRYGB 32,130 and LSG 33,563) at ACS NSQIP bariatric surgery programs. VTE rates remained stable at ACS NSQIP bariatric surgery programs from 2010 to 2016 (0.45, 0.45, 0.45, 0.25, 0.35, 0.3, and 0.3%). In contrast, VTE rates at BMI Abu Dhabi decreased from 2.2% in 2011 to 0.35% after we adopted an aggressive strategy to VTE without an increase in bleeding complications. LRYGB patients with VTE had higher OR time, leak, collection, and mortality at ACS NSQIP hospitals compared to those at BMI Abu Dhabi. In contrast, rates were similar in LSG patients with VTE.

CONCLUSION

Changing our approach to VTE management led our VTE rates to decrease and become like those of ACS NSQIP bariatric surgery patients in LSG and LRYGB.

[Venous thromboembolism and urological cancer: Epidemiology and therapeutically management]

INTRODUCTION

Active cancer is a risk factor in the occurrence of venous thromboembolism (VTE). This is the second cause of death for these patients. In onco-urology, some cancers are associated with an increased risk of VTE. The aim of this study was to propose a focus of epidemiology and VTE therapy management.

MATERIAL AND METHODS

A systematic analysis of the PubMed^® database was performed through the PRISMA methodology using the followings keywords : "neoplasm", "venous thromboembolism", "prophylaxis", "pulmonary embolism", "urology". The original papers were included with a priority on: meta-analyzes, literature reviews, randomized controlled trials and good-level proof cohort studies. Only publications in English or French have been selected.

RESULTS

The incidence of VTE was more important in case of renal carcinomas (3.5%/year). When surgery was proposed cystectomy was the riskiest procedure (2.6 to 11.6% VTE). Chemotherapy alone was an important risk factor increasing by a factor of six the occurrence of VTE. Hormonotherapy also increased this risk by induced hypogonadism. The curative treatment for VTE associated with cancers has to be performed through the injection of low molecular weight heparin. The implantation of a prophylactic treatment was not systematic among patients diagnosed with urological cancer.

CONCLUSION

The understanding of mechanisms associated with the occurrence of VTE among these patients has enabled to improve patient management, especially those suffering from urological cancer. Undeniably, frequency of VTE is probably underestimated by urologists during clinical practice.

Venous thromboembolism prophylaxis may cause more harm than benefit: an evidence-based analysis of Canadian and international guidelines

A majority of deep vein thromboses identified in screening studies of hospitalized patients remain clinically insignificant. Guidelines based on these studies markedly overestimate the risk of clinical venous thromboembolism (VTE) and the benefit of heparin prophylaxis. Accordingly, in 2012, the American College of Chest Physicians (ACCP) removed screening studies from the 9th edition of its Antithrombotic and Thrombolytic Therapy guideline (AT9), and downgraded recommendations. Involvement of authors of the 8th edition (AT8) was restricted due to financial and intellectual conflicts of interest. However, the first author of AT8 subsequently wrote a "Getting Started Kit," widely distributed to help Canadian hospitals develop VTE protocols. Based on screening studies reporting asymptomatic VTE, it lacks estimates of the magnitudes of benefit or harm from low molecular weight heparin (LMWH), yet advises prophylaxis in almost all hospitalized patients. Most Canadian hospitals have implemented guidelines based on this kit. Guidelines from the U. K National Institute for Health and Care Excellence and the U.S. Agency for Healthcare Research and Quality recommend a similar approach. However, a critical review of evidence reveals that most hospitalized patients have a risk of clinical VTE equal to or lower than the bleeding risk from LMWH. Most hospitalized patients should not receive LMWH until and unless randomized trials show more benefit than harm. Guidelines recommending liberal LMWH prophylaxis in hospitalized patients are not evidence based and should be critically re-examined.

Routine Use of Low-Molecular-Weight Heparin For Deep Venous Thrombosis Prophylaxis After Foot and Ankle Surgery: A Cost-Effectiveness Analysis

The purpose of the present study was to determine whether certain foot/ankle surgeries would benefit from the routine use of low-molecular-weight heparin (LMWH) as postoperative deep venous thrombosis prophylaxis. We conducted a formal cost-effectiveness analysis using a decision analytic tree to explore the healthcare costs and health outcomes associated with a scenario of no prophylaxis and a scenario of routine LMWH prophylaxis for 4 weeks. The 2 scenarios were compared for 5 procedures: (1) Achilles tendon repair (ATR), (2) total ankle arthroplasty (TAA), (3) hallux valgus surgery (HVS), (4) hindfoot arthrodesis (HA), and (5) ankle fracture surgery (AFS). The outcomes assessed included short- and long-term costs, quality-adjusted life-years (QALYs), and incremental cost per QALY gained. The costs were evaluated from the healthcare system perspective and are expressed in U.S. dollars at a 2015 price base. In the short term, routine prophylaxis was always associated with greater costs compared with no prophylaxis. For ATR, TAA, HA, and AFS, prophylaxis was associated with slightly better health outcomes; however, the gain in QALYs was minimal compared with the cost of prophylaxis (incremental cost-effectiveness ratio well above $50,000/QALY threshold). For HVS, prophylaxis was associated with both worse health outcomes and greater costs. In the long term, routine prophylaxis was always associated with worse health outcomes and either cost more (HA, AFS, HVS) or saved very little (ATR, TAA). We concluded that policies encouraging the routine use of LMWH after foot/ankle surgery are unlikely to be cost-effective. Decisions to perform prophylaxis should be on a case-by-case basis and should emphasize individual patient risk factors.

Surgical Complications of Urinary Diversion

Urinary diversion (UD) with an intestinal segment has significant risks of short- and long-term complications. With modern reporting criteria, understanding of the true prevalence and spectrum of these complications has improved. Methods to minimize early postoperative complications include enhanced recovery pathways, restricted intraoperative fluid protocols, and referral to high-volume centers. With long-term follow-up after UD, the risk of complications steadily rises. Late surgical complications include ureterointestinal anastomotic strictures, urolithiasis, and stomal issues. Patients with UDs require close surveillance to monitor for anatomic, infectious, and metabolic complications and surgeons who perform UD should be aware of the risk and timing of postoperative complications.

Family history of venous thromboembolism as a risk factor and genetic research tool

Familial clustering of venous thromboembolism (VTE) was described as far back as 1905 by Briggs. Although Egeberg discovered inherited deficiency of antithrombin in 1965, it was not until Dahlback discovered resistance to activated protein C in 1993 that it became clear that genetic factors are common risk factors of VTE. Several genes have been linked to familial aggregation of VTE and genome-wide association studies have found several novel gene loci. Still, it has been estimated that much of the heritability for VTE remains to be discovered. Family history (FH) of VTE is therefore still important to determine whether a patient has an increased genetic risk of VTE. FH has the potential to represent the sum of effects and interactions between environmental and genetic factors. In this article the design, methodology, results, clinical and genetic implications of FH studies of VTE are reviewed. FH in first-degree relatives (siblings and/or parents) is associated with a 2–3 times increased familial relative risk (FRR). However, the FRR is dependent on age, number of affected relatives, and presentation of VTE (provoked/unprovoked). Especially high familial risks are observed in individuals with two or more affected siblings (FFR> 50). However, the familial risk for recurrent VTE is much lower or non-significant. Moreover, FH of VTE appears mainly to be important for venous diseases (i. e. VTE and varicose veins). The familial associations with other diseases are weaker. In conclusion, FH of VTE is an important research tool and a clinically potential useful risk factor for VTE.

Incidence and Risk Factors of Venous Thromboembolism After Orthopaedic Foot and Ankle Surgery

BACKGROUND

This study examines the incidence and risk of postoperative symptomatic venous thromboembolism (VTE) after orthopaedic foot/ankle surgery.

MATERIALS

Patients that received foot/ankle surgery between 2006 and 2016 were reviewed. Inclusion criteria were surgical patients that were without coagulopathy, previous VTE, and/or using anticoagulation medications including aspirin. Age, sex, body mass index, medical comorbidities, and surgical diagnosis and procedure(s) were noted. Records were reviewed to see who developed a symptomatic VTE within 90 days from surgery.

RESULTS

This study involved 2774 patients that received foot/ankle surgery between 2006 and 2016. Of them, 22 (0.79%) developed a VTE within 90 days from surgery. The mean age of these patients was 49.5 years. Twelve patients were male and 10 were female. Sixteen patients were obese and 6 were nonobese. Postoperative VTEs were 14 infrapopliteal deep vein thrombosis (DVT), 1 suprapopliteal DVT, and 7 pulmonary emboli. The most common surgeries involved were ankle fracture repair in 8 (0.29%), Achilles tendon repair in 2 (0.07%), ankle ligament reconstruction in 2, and hammer-toe correction in 2 patients. Obesity was predictive of a postoperative VTE to a statistically significant degree (P = .04). Age, sex, medical comorbidities, diagnosis, and type of surgery were not significantly prognostic for a postsurgical VTE (P ≥ .05).

DISCUSSION

The incidence of VTE after foot/ankle surgery is low. However, obese patients are at significantly higher risk for VTE after such procedures.

CLINICAL RELEVANCE

These findings are important when educating patients as to their risks of developing a VTE after orthopaedic foot/ankle surgery.

LEVELS OF EVIDENCE

Level III: Retrospective cohort study.

Trends in Perioperative Venous Thromboembolism Associated with Major Noncardiac Surgery

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

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

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

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

Who Should Get Extended Thromboprophylaxis After Bariatric Surgery?: A Risk Assessment Tool to Guide Indications for Post-discharge Pharmacoprophylaxis

OBJECTIVE

To determine the risk factors for 30-day postdischarge venous thromboembolism (VTE) after bariatric surgery and to identify potential indications for extended pharmacoprophylaxis.

BACKGROUND

VTE is among most common causes of death after bariatric surgery. Most VTEs occur after hospital stay; still a few patients receive extended pharmacoprophylaxis postdischarge.

METHODS

From American College of Surgeons-National Surgical Quality Improvement Program, we identified 91,963 patients, who underwent elective primary and revisional bariatric surgery between 2007 and 2012. Regression-based techniques were used to create a risk assessment tool to predict risk of postdischarge VTE. The model was validated using the 2013 American College of Surgeons-National Surgical Quality Improvement Program dataset (N = 20,575). Significant risk factors were used to create a user-friendly online risk calculator.

RESULTS

The overall 30-day incidence of postdischarge VTE was 0.29% (N = 269). In those experiencing a postdischarge VTE, mortality increased about 28-fold (2.60% vs 0.09%; P < 0.001). Among 45 examined variables, the final risk-assessment model contained 10 categorical variables including congestive heart failure, paraplegia, reoperation, dyspnea at rest, nongastric band surgery, age ≥60 years, male sex, BMI ≥50 kg/m, postoperative hospital stay ≥3 days, and operative time ≥3 hours. The model demonstrated good calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.71) and discrimination (c-statistic = 0.74). Nearly 2.5% of patients had a predicted postdischarge VTE risk >1%.

CONCLUSIONS

More than 80% of post-bariatric surgery VTE events occurred post-discharge. Congestive heart failure, paraplegia, dyspnea at rest, and reoperation are associated with the highest risk of post-discharge VTE. Routine post-discharge pharmacoprophylaxis can be considered for high-risk patients (ie, VTE risk >0.4%).

A Scoring System to Stratify Curability after Endoscopic Submucosal Dissection for Early Gastric Cancer: "eCura system"

OBJECTIVES

Although radical surgery is recommended for patients not meeting the curative criteria for endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) because of the potential risk of lymph node metastasis (LNM), this recommendation may be overestimated and excessive. We aimed to establish a simple scoring system for decision making after ESD.

METHODS

This multicenter retrospective study consisted of two stages. First, the risk-scoring system for LNM was developed using multivariate logistic regression analysis in 1,101 patients who underwent radical surgery after having failed to meet the curative criteria for ESD of EGC. Next, the system was internally validated by survival analysis in another 905 patients who also did not meet the criteria and did not receive additional treatment after ESD.

RESULTS

In the development stage, based on accordant regression coefficients, five risk factors for LNM were weighted with point values: three points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. Then, the patients were categorized into three LNM risk groups: low (0-1 point: 2.5% risk), intermediate (2-4 points: 6.7%), and high (5-7 points: 22.7%). In the validation stage, cancer-specific survival differed significantly among these groups (99.6, 96.0, and 90.1%, respectively, at 5 years; P<0.001). The C statistic of the system for cancer-specific mortality was 0.78.

CONCLUSIONS

This scoring system predicted cancer-specific survival in patients who did not meet the curative criteria after ESD for EGC. ESD without additional treatment may be an acceptable option for patients at low risk.

Endotoxaemia-augmented murine venous thrombosis is dependent on TLR-4 and ICAM-1, and potentiated by neutropenia

Venous thromboembolism is a major cause of death during and immediately post-sepsis. Venous thrombosis (VT) is mediated by cell adhesion molecules and leukocytes, including neutrophil extracellular traps (NETs). Sepsis, or experimentally, endotoxaemia, shares similar characteristics and is modulated via toll like receptor 4 (TLR4). This study was undertaken to determine if endotoxaemia potentiates early stasis thrombogenesis, and secondarily to determine the role of VT TLR4, ICAM-1 and neutrophils (PMNs). Wild-type (WT), ICAM-1^-/- and TLR4^-/- mice underwent treatment with saline or LPS (10 mg/kg i. p.) alone, or followed by inferior vena cava (IVC) ligation to generate stasis VT. In vivo microscopy of leukocyte trafficking was performed in non-thrombosed mice, and tissue and plasma were harvested during early VT formation. Pre-thrombosis, circulating ICAM-1 was elevated and increased leukocyte adhesion and rolling occurred on the IVC of LPS-treated mice. Post-thrombosis, endotoxaemic mice formed larger, platelet-poor thrombi. Endotoxaemic TLR4^-/- mice did not have an augmented thrombotic response and exhibited significantly decreased circulating ICAM-1 compared to endotoxaemic WT controls. Endotoxaemic ICAM-1^-/- mice had significantly smaller thrombi compared to controls. Hypothesising that PMNs localised to the inflamed endothelium were promoting thrombosis, PMN depletion using anti-Ly6G antibody was performed. Paradoxically, VT formed without PMNs was amplified, potentially related to endotoxaemia induced elevation of PAI-1 and circulating FXIII, and decreased uPA. Endotoxaemia enhanced early VT occurs in a TLR-4 and ICAM-1 dependent fashion, and is potentiated by neutropenia. ICAM-1 and/or TLR-4 inhibition may be a unique strategy to prevent sepsis-associated VT.

The Efficacy and Safety of Edoxaban for VTE Prophylaxis Post-Orthopedic Surgery: A Systematic Review

BACKGROUND

Venous thromboembolism (VTE) is a common complication that manifests during and/or after hospitalization, as well as postsurgeries including orthopedic surgeries. Edoxaban is a new oral direct factor Xa inhibitor that has been recently approved for treating VTE in patients who have already been treated with a parenteral anticoagulant and for the prevention of stroke and non-central nervous system systemic embolism in patients with nonvalvular atrial fibrillation.

OBJECTIVES

The purpose of this systematic review was to evaluate the safety and efficacy of edoxaban for VTE prophylaxis after lower limb orthopedic surgery.

MATERIALS AND METHODS

A comprehensive search was conducted in Google Scholar, PubMed, MEDLINE, and ScienceDirect to identify potential records, then titles, abstracts, and full texts were screened using the inclusion criteria to filter out irrelevant studies. Moreover, the data extraction and quality assessment were undertaken using standardized tools, and the results were narratively synthesized and presented in tables.

RESULTS

Six studies were included in this systematic review after screening 2989 records. The majority of studies demonstrated a statistically significant reduction in VTE events in the edoxaban group(s) compared to the dalteparin, placebo, or enoxaparin groups (P < .05). The differences in VTE cases in some studies reached to approximately 50% favoring edoxaban 30 mg over the comparator (P < .05). However, other studies uncovered a statistically insignificant difference between edoxaban and the comparator "enoxaparin" when used for VTE prophylaxis (P > .05). On the other hand, although edoxaban found to cause more bleeding, the differences between edoxaban and the comparator are statistically insignificant (P > .05).

CONCLUSION

This study helped to amalgamate evidence with regard to the use of edoxaban for VTE prophylaxis post-lower limb orthopedic surgery. In line with the results of the reviewed studies, edoxaban seems to be highly effective in reducing VTE post-lower limb orthopedic surgery.

Venous thromboembolism in head and neck cancer surgery

Background

Venous thromboembolism (VTE) is a major cause of perioperative morbidity and mortality. Historically, otolaryngology surgery has been seen as very low risk of VTE, given the relatively short procedures and healthy patient population. However, head and neck surgery patients have multiple additional risk factors for VTE compared to general otolaryngology patients, and only recently has research been directed at examining this population of patients regarding VTE risk.

Review

VTE has long been recognized as a major issue in other surgical specialties, with VTE rates of 15–60 % in some specialties in the absence of prophylaxis with either mechanical compression or anticoagulation. Multiple large-scale retrospective studies have shown that the incidence of VTE in otolaryngology patients is quite low, ranging between 0.1 and 1.6 %. However, these studies indicated that head and neck cancer patients may have an increased risk of VTE. Further retrospective studies focusing on head and neck cancer patients found a VTE rate of approximately 2 %, but one study also found a suspected VTE rate of 5.6 % based on clinical symptoms, indicating that retrospective studies may underreport the true incidence. A single prospective study found a 13 % risk of VTE after major head and neck surgery. Furthermore, risk stratification using the Caprini risk assessment model demonstrates that the highest risk patients may have a VTE risk of 18.3 %, although this may be lowered (but not eliminated) through the use of appropriate prophylactic anticoagulation.

Conclusion

VTE is likely a more significant concern in head and neck surgery patients than previously realized. Appropriate prophylaxis with mechanical compression and anticoagulation is essential; risk stratification may serve as a useful tool to identify head and neck cancer patients at highest risk for VTE.

Impact of recent guideline changes on aspirin prescribing after knee arthroplasty

BACKGROUND

Prior to 2012, the American Academy of Orthopaedic Surgeons (AAOS) and American College of Chest Physicians (ACCP) differed in their recommendations for postoperative pharmacologic venous thromboembolism prophylaxis (VTEP) after total joint arthroplasty. More specifically, aspirin (ASA) monotherapy was not endorsed by the ACCP as an acceptable prophylaxis. In 2012, the ACCP supported ASA monotherapy compared with no prophylaxis. Our aim was to investigate the impact of the convergence of ACCP and AAOS recommendations on surgeon prescribing patterns after knee arthroplasty (KA).

METHODS

This is a retrospective chart review. We collected data to assess preoperative VTE risk and examined VTEP prescriptions on postoperative day 1 (POD1) and at discharge (D/C) from 7/2008 to 12/2011 (pre-period) and 1/2012 to 7/2014 (post-period). Adult patients undergoing primary and revision KA were identified by ICD-9 procedure codes. Patients on preoperative full-dose anticoagulation and with hypercoagulability disorders were excluded.

RESULTS

Of 368 records reviewed, 329 were included in the analysis. There were no differences between the two period groups for age, sex, BMI, estrogen therapy, malignancy, smoking status, prior VTE, bilateral procedures, or surgery within 3 months. On POD1, in the pre-period, 4.6 % were prescribed ASA monotherapy versus 44.4 % in the post-period (p < 0.001). On D/C, in the pre-period, 13.9 % were prescribed ASA versus 55.6 % in the post-period (p < 0.001).

CONCLUSIONS

Our results indicate a statistically significant change in orthopedist prescribing patterns after guideline convergence. Furthermore, there was no apparent change in VTE risk between the two study groups when excluding patients necessitating full anticoagulation. Prior literature has shown that the divergence in guidelines influenced physicians away from ASA and toward more potent anticoagulants in order to avoid potential litigation. Once its role in VTEP was supported by the ACCP, it appears that ASA monotherapy was readily and rapidly incorporated into clinical practice. ASA may be favored over other VTEP agents for its lower bleeding risk profile and cost. This study highlights the profound impact clinical practice guidelines have on clinician prescribing patterns. Although prospective randomized trials are needed to compare the efficacy of ASA with other VTEP agents, ASA is now a predominant part of the VTEP armamentarium after KA.