Postoperative Chemoprophylaxis Research Articles

Immediate vs. delayed venous thromboembolism prophylaxis following spine surgery: increased rate of unplanned reoperation for postoperative hematoma with immediate prophylaxis

BACKGROUND CONTEXTThere is significant variability in postoperative chemoprophylaxis protocols amongst spine providers due to perceived risks and benefits, but limited data on the topic. At our institution, both orthopaedic spine and neurosurgery departments utilize unfractionated subcutaneous heparin in identical dosages and frequency, with the only difference being time to initiation postoperatively. PURPOSETo evaluate the rate of symptomatic venous thromboembolism (VTEs) and unplanned reoperation for hematoma based on timing of chemoprophylaxis initiation. STUDY DESIGN/SETTINGSingle institution retrospective cohort study. PATIENT SAMPLEPatients undergoing elective spine surgery, excluding patients undergoing surgery in the setting of trauma, malignancy, or infection OUTCOME MEASURESOutcome measures included the diagnosis of a venous thromboembolism within 90 days of surgery and unplanned reoperation for a hematoma METHODSPatients undergoing elective spine surgery from 2017 to 2021 were grouped based on chemoprophylaxis protocol. In the “immediate” group, patients received subcutaneous heparin 5000 units every 8 hours starting immediately after surgery, and in the “delayed” group, patients received chemoprophylaxis starting postoperative day (POD)-2 for any decompressions and/or fusions involving a spinal cord level (i.e., L2 and above) and POD-1 for those involving only levels below the spinal cord (i.e., L3 to pelvis). A cox proportional hazards model was created to assess independent predictors of venous thromboembolic events, while a logistic regression was utilized for unplanned reoperations for hematoma. RESULTSOf 8,704 patients, a total of 98 (1.13%) VTE events occurred, of which 43 (0.49%) were pulmonary embolism. Fifty-four patients (0.62%) had unplanned reoperations for postoperative hematomas. On cox proportional hazards model analysis, immediate chemoprophylaxis was not protective of a venous thromboembolism (Hazard Ratio: 1.18, p=.436), but, it was a significant independent predictor for unplanned reoperation for hematoma on multivariable logistic regression modeling (Odds Ratio: 3.29, p<.001). CONCLUSIONSBoth chemoprophylaxis protocols in our study resulted in low rates of VTE and postoperative hematoma. However, our findings suggest that the delayed chemoprophylaxis protocol may mitigate postoperative hematoma formation without increasing the risk for a thrombotic event.

Trends in Venous Thromboembolism and Chemoprophylaxis Utilization in Elective Total Knee Arthroplasty From 2011 to 2020

BackgroundVenous thromboembolism (VTE) is a feared complication of joint arthroplasty, leading to recent clinical practice guidelines aimed at VTE prevention and prophylaxis. However, limited studies have examined national changes in practice regarding chemoprophylaxis and the resultant changes in VTE rates. The purpose of this study was to identify: (1) the temporal trends in thrombotic complications; and (2) changes in chemoprophylaxis utilization in patients undergoing elective total knee arthroplasty (TKA). MethodsA retrospective study was conducted using a large all-payer claims dataset. Patients who underwent osteoarthritis-indicated TKA between 2011 and 2020 were identified. Annual rates of VTE, including deep vein thrombosis and pulmonary embolism, within 90 days of TKA were determined. Utilization patterns for postoperative aspirin and anticoagulant medications were observed. Temporal trends were analyzed with linear regression and the calculation of the cumulative annual growth rate. Multivariable logistic regression was conducted to account for the effects of age and comorbidities. ResultsA total of 1,263,351 TKA patients were identified between 2011 and 2020. There were significant reductions in VTE rates (2.9% in 2011 to 1.8% in 2020), deep vein thrombosis rates (2.0% in 2011 to 1.3% in 2020), and pulmonary embolism rates (1.1% in 2011 to 0.6% in 2020). Postoperative utilization of aspirin increased from 5.9% in 2011 to 53.2% in 2020, whereas utilization of anticoagulants decreased from 94.1% in 2011 to 46.8% in 2020. Among anticoagulants, direct factor Xa inhibitors had the greatest increase in utilization (4.6 to 69.7%). The average reimbursement associated with VTE after TKA decreased from $18,061 in 2011 to $7,835 in 2020. ConclusionsThe incidence rate and economic burden of VTE after TKA have significantly declined since 2011. There has been a trend toward increased aspirin and direct oral anticoagulant utilization for postoperative chemoprophylaxis. Level of EvidenceLevel III.

Venous thromboembolism chemical prophylaxis after skull base surgery

PurposeThere is no guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using pharmacological agents (chemoprophylaxis) in patients undergoing skull base surgery. The aim of this study was to compare VTE and intracranial haematoma rates after skull base surgery in patients treated with/without chemoprophylaxis.MethodsReview of prospective quaternary centre database including adults undergoing first-time skull base surgery (2009–2020). VTE was defined as deep vein thrombosis (DVT) and pulmonary embolism (PE) within 6 months of surgery. Multivariate logistic regression was used to determine factors predictive of postoperative intracranial haematoma/VTE. Propensity score matching (PSM) was used in group comparisons.ResultsOne thousand five hundred fifty-one patients were included with a median age of 52 years (range 16–89 years) and female predominance (62%). Postoperative chemoprophylaxis was used in 81% of patients at a median of 1 day postoperatively. There were 12 VTE events (1.2%), and the use of chemoprophylaxis did not negate the risk of VTE entirely (p > 0.99) and was highest on/after postoperative day 6 (9/12 VTE events). There were 18 intracranial haematomas (0.8%), and after PSM, chemoprophylaxis did not significantly increase the risk of an intracranial haematoma (p > 0.99). Patients administered chemoprophylaxis from postoperative days 1 and 2 had similar rates of intracranial haematomas (p = 0.60) and VTE (p = 0.60), affirmed in PSM.ConclusionPostoperative chemoprophylaxis represents a relatively safe strategy in patients undergoing skull base surgery. We advocate a personalised approach to chemoprophylaxis and recommend it on postoperative days 1 or 2 when indicated.

D122. The Impact of Tamoxifen Therapy on Thrombotic Flap Complications: A Nationwide Analysis

PURPOSE: Perioperative tamoxifen practices in microvascular breast reconstruction vary widely. However, no prior literature has investigated this issue from a national standpoint. Thus, this study investigated: (1) the impact of tamoxifen therapy on microvascular flap outcomes using nationwide data, and (2) amongst those on tamoxifen therapy, the impact of perioperative tamoxifen use on flap outcomes. METHODS: This was a retrospective cohort investigation using Truven MarketScan Databases (2014-2017). All women who underwent microvascular breast reconstruction were included; prescriptions claims data was used to identify those on tamoxifen. Outcomes were compared between tamoxifen/non-tamoxifen cohorts. Subgroup analyses in the tamoxifen cohort were undertaken to investigate whether perioperative tamoxifen use impacted outcomes. RESULTS: Overall, 5,832 women were included, of whom 1,983 (34%) were on tamoxifen. There were no differences in flap-related adverse events between tamoxifen and non-tamoxifen cohorts (OR: 1.00; 95%CI: 0.79-1.31; p=0.38). However, amongst patients determined to be at high risk for thrombotic complications, those on tamoxifen therapy had a significantly higher risk of 90-day postoperative venous thromboembolism (OR: 1.15; 95%CI: 1.01-1.28; p=0.04). There were no significant differences in flap failure between those who held tamoxifen versus those who continued tamoxifen into the perioperative period. CONCLUSION: Upon review of national data, preoperative tamoxifen therapy did not significantly increase flap complications/failure after microvascular breast reconstruction. However, patients on tamoxifen therapy with thrombotic risk factors as determined by the Caprini risk score were found to have greater risk for postoperative venous thromboembolism- such patients may need special consideration for postoperative chemoprophylaxis.

Safety and Efficacy of Extended Postdischarge Venous Thromboembolism Prophylaxis in Microsurgical Breast Reconstruction.

The PearlDiver database was queried for MBR patients who did not receive postdischarge VTE prophylaxis (cohort 1) and MBR patients discharged with enoxaparin for at least 14 days (cohort 2), then queried for hematoma, deep venous thrombosis (DVT), and/or pulmonary embolism. Concurrently, a systematic review was undertaken to identify studies investigating VTE with postoperative chemoprophylaxis. In total, 13,541 patients in cohort 1 and 786 patients in cohort 2 were identified. The incidence of hematoma, DVT, and pulmonary embolism were 3.51%, 1.01%, 0.55% in cohort 1, and 3.31%, 2.93%, and 1.78% in cohort 2, respectively. There was no significant difference in hematoma between these two cohorts (P = 0.767); however, a significantly lower rate of DVT (P < 0.001) and pulmonary embolism (P < 0.001) occurred in cohort 1. Ten studies met systematic review inclusion. Only three studies reported significantly lower VTE rates with postoperative chemoprophylaxis. Seven studies found no difference in bleeding risk. This is the first study utilizing a national database and a systematic review to investigate extended postoperative enoxaparin in MBR. Overall, rates of DVT/PE seem to be declining compared with previous literature. The results of this study suggest that there remains a lack of evidence supporting extended postoperative chemoprophylaxis, although the therapy appears safe in that it does not increase bleeding risk.

Using machine learning and big data for the prediction of venous thromboembolic events after spine surgery: A single-center retrospective analysis of multiple models on a cohort of 6869 patients.

Venous thromboembolic event (VTE) after spine surgery is a rare but potentially devastating complication. With the advent of machine learning, an opportunity exists for more accurate prediction of such events to aid in prevention and treatment. Seven models were screened using 108 database variables and 62 preoperative variables. These models included deep neural network (DNN), DNN with synthetic minority oversampling technique (SMOTE), logistic regression, ridge regression, lasso regression, simple linear regression, and gradient boosting classifier. Relevant metrics were compared between each model. The top four models were selected based on area under the receiver operator curve; these models included DNN with SMOTE, linear regression, lasso regression, and ridge regression. Separate random sampling of each model was performed 1000 additional independent times using a randomly generated training/testing distribution. Variable weights and magnitudes were analyzed after sampling. Using all patient-related variables, DNN using SMOTE was the top-performing model in predicting postoperative VTE after spinal surgery (area under the curve [AUC] =0.904), followed by lasso regression (AUC = 0.894), ridge regression (AUC = 0.873), and linear regression (AUC = 0.864). When analyzing a subset of only preoperative variables, the top-performing models were lasso regression (AUC = 0.865) and DNN with SMOTE (AUC = 0.864), both of which outperform any currently published models. Main model contributions relied heavily on variables associated with history of thromboembolic events, length of surgical/anesthetic time, and use of postoperative chemoprophylaxis. The current study provides promise toward machine learning methods geared toward predicting postoperative complications after spine surgery. Further study is needed in order to best quantify and model real-world risk for such events.

Optimal Timing of Perioperative Chemical Thromboprophylaxis in Elective Major Abdominal Surgery: A Systematic Review and Meta-analysis.

To investigate the effect of the timing of chemoprophylaxis on venous thromboembolisms (VTEs) and bleeding rates in patients undergoing major abdominal surgery. Postoperative bleeding and VTE incur significant morbidity, mortality, and health care costs. Chemoprophylaxis is used routinely to prevent VTEs but increases bleeding risk. The perioperative timing of chemoprophylaxis initiation may influence both VTE and bleeding risks. The optimal window for commencing chemoprophylaxis in the perioperative period is unclear. MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were searched using PRISMA guidelines. Randomized trials and cohort studies published between January 1, 2000 to May 10, 2022, which reported on chemoprophylaxis timing as well as the incidence of VTE and bleeding after elective abdominal surgery were meta-analyzed. From 6175 studies, 14 (24,922 patients) were meta-analyzed. Bariatric (4 studies), antireflux (1 study), hepato-pancreatic-biliary (5 studies), colorectal (1 study), ventral hernia (1 study), and major intra-abdominal surgeries (2 studies) were included. Chemoprophylaxis was initiated before skin closure in 10,403 patients, and postoperatively in 14,519 patients. Both symptomatic [risk ratios (RR), 0.81; 95% CI, 0.45-1.43; P =0.460] and overall (RR, 0.74; 95% CI, 0.45-1.24; P =0.250) VTE rates were comparable between study groups. Compared with postoperative chemoprophylaxis, early usage increased the risk of all bleeding (RR, 1.56; 95% CI, 1.13-2.15; P =0.007), major bleeding (RR, 1.63; 95% CI, 1.16-2.28; P =0.005), blood transfusion (RR, 1.48; 95% CI, 1.24-1.76; P <0.001), and reintervention (RR, 1.94; 95% CI, 1.19-3.18; P =0.008). Our findings advocate for initiating chemoprophylaxis postoperatively in elective abdominal surgery to minimize bleeding risk without compromising VTE protection.

Assessment of BMI and Venous Thromboembolism Rates in Patients on Standard Chemoprophylaxis Regimens After Undergoing Free Tissue Transfer to the Head and Neck

Venous thromboembolism (VTE) is a severe complication after free tissue transfer to the head and neck (H&N). Enoxaparin 30 mg twice daily (BID) is a common regimen for chemoprophylaxis. However, differences in enoxaparin metabolism based on body weight may influence its efficacy and safety profile. To assess the association between BMI and postoperative VTE and hematoma rates in patients treated with prophylactic enoxaparin 30 mg BID. This was a retrospective review of a prospectively collected cohort from 2012 to 2022. Postoperative VTE, hematoma, and free flap pedicle thrombosis were recorded within 30 days of index surgery. The setting was a tertiary academic referral center. Participants included patients undergoing H&N reconstruction with free flaps that received fixed-dose subcutaneous enoxaparin 30 mg BID postoperatively. Statistical analysis was conducted from April to May 2022. Outcomes include incidence of VTE, hematoma, and flap pedicle thrombosis events within 30 days of the surgery. Univariate and multivariable regression models were used to evaluate associations between BMI and other patient factors with these outcomes. Among the 765 patients included, 262 (34.24%) were female; mean (SD) age was 60.85 (12.64) years; and mean (SD) BMI was 26.36 (6.29). The rates of VTE and hematoma in the cohort were 3.92% (30 patients) and 5.09% (39 patients), respectively. After adjusting for patient factors, BMI was the only factor associated with VTE (OR, 1.07; 95% CI, 1.015-1.129). Obesity (BMI >30) was associated with increased odds of VTE (OR, 2.782; 95% CI, 1.197-6.564). Hematoma was not associated with BMI (OR, 0.988; 95% CI, 0.937-1.041). Caprini score of at least 9 was not associated with VTE (OR, 1.259; 95% CI, 0.428-3.701). This cohort study found that obesity was associated with an increased risk of VTE in patients after microvascular H&N reconstruction and while on standard postoperative chemoprophylaxis regimens. This association may suggest insufficient VTE prophylaxis in this group and a potential indication for weight-based dosing.

Incidence of Venous Thromboembolism Following TAA: Does Chemoprophylaxis Work?

Category: Ankle Arthritis; Ankle; Other Introduction/Purpose: Venous thromboembolism is a devastating and costly complication following TAA. The true incidence of VTE is unknown and the decision to prescribe chemoprophylaxis in foot and ankle surgery continues to be debated. At our institution, all patients receive a four-week course of chemoprophylaxis following TAA. The purpose of this study was to evaluate the incidence of VTE at our institution in patients receiving routine chemoprophylaxis. Methods: Following institutional board approval, a retrospective chart review was conducted for all patients that underwent TAA from 2018-2021 by a single surgeon. Patients were followed from the time of surgery to their six-week follow-up. Demographics and the type of chemoprophylaxis was recorded. For comparison, a large online database was queried using ICD and CTP codes in order to determine the incidence of VTE at 2 week and 6 weeks postoperatively for patients that underwent TAA and did not receive any form of chemoprophylaxis. Results: At our institution, from 2018-2021, 56 patients underwent TAA. The mean age of our cohort was 60.9 (Range, 56-83). In our cohort, 31 patients were male, 25 were female, and the mean patient BMI was 33.8 (Range, 21-56.2). Of the 56 patients, 12 received aspirin (81 mg), 25 received aspirin (325 mg), 16 received enoxaparin (40 mg), 2 received apixaban (5 mg), and 1 received rivaroxaban (20 mg). The total incidence of VTE at 6 weeks was 0%. For comparison, using a large online database (from 2011- 2021), 1,463 patients underwent TAA and did not receive postoperative chemoprophylaxis. Of these patients, 13 (0.89%) developed a postoperative VTE at 6-weeks following surgery. Conclusion: At our institution, the rate of VTE at 6-weeks postoperatively was 0%. This was lower than a large online database rate (0.89%) in patients that did not receive chemoprophylaxis. Further investigation is needed.

Prediction of Venous Thromboembolism after Ankle Fractures using Machine Learning: To Give Prophylaxis or Not to Give, That is the Question

Category: Ankle; Other Introduction/Purpose: The risk of venous thromboembolism (VTE) after foot and ankle surgery is significantly lower than rates after hip/knee arthroplasty, but it isn't zero. Specific subgroups of patients may be at higher risk, forcing patients and clinicians to navigate the risks and benefits of chemoprophylaxis with insufficient data. Efforts have been made to add clarity to such decision making using conventional data-analysis and risk-scoring methods, but none of these methods were patient-specific or built on robust models of a given patient's individual characteristics. In this study we used machine-learning to determine the potential risk factors for VTE after ankle fracture. We aimed to develop a patient-specific predictive model to assist clinicians and patients in deciding upon the use of postoperative chemoprophylaxis after foot and ankle surgery. Methods: In this preliminary machine-learning-based case-control study, 16,421 patients with ankle fractures were recruited retrospectively. We used an automated-string search method to find patients who were clinically suspected to have developed VTE. Among 1176 such patients, 239 had confirmed VTE within 180 days of sustaining an ankle fracture (cases) and 937 did not (controls). Groups were further sub-divided in patients who had been receiving chemoprophylaxis and those who hadn't. Over 110 factors and variables including patient demographics, past-medical and surgical history, fracture characteristics, treatment, medications, and laboratory values were included in our machine-learning dataset. Three analytical algorithms were used in our machine-learning methods including backward-logistic-regression, decision-tree-classifier (depth=5), and neural networks (two dense layers (n=16 and 4), two drop-out layers, and a sigmoid classifier). Conventional statistics were also used to compare the case and control groups (chi-squared, t-test, p&lt;0.05 considered significant), and the odds-ratio (OR) was calculated for significant parameters. Results: Based on overall performance scores including specificity, sensitivity, area under the ROC curve, accuracy, PPV, NPV, F- 1 score, among the 3 machine-learning methods, the Backward-Logistic-Regression model was superior in predicting VTE post ankle fracture and in determining whether administering prophylaxis can be beneficial for the patient or not (Tables 1 and 2). Other than the previously suggested risk factors, our algorithms showed a positive correlation between the incidence of VTE and smoking (OR=2.09, p&lt;0.001), age &lt;55 y/o (p=0.001), open fracture (OR=2.49, p&lt;0.001), male sex (OR=1.98, p&lt;0.001), surgical versus nonoperative treatment (OR=1.88, p=0.001), and multiple fractures at the time of trauma (OR=1.9, p=0.001). Factors that showed negative correlation with VTE include statins use (OR=0.36, p&lt;0.001), hypertension (OR=0.53, p=0.001), vitamin D (OR=0.43, 0.002), calcium supplementation (OR= 0.43, p= 0.01), hyperlipidemia (OR=0.55, p=0.006), cataract (OR=0.19, p=0.01), osteoporosis (OR=0.36, p=0.02), cardiovascular diseases (OR=0.54, p=0.02), hypokalemia (OR=0.26, p=0.03), and proton pump inhibitor use (OR=0.5, p=0.03). Conclusion: Our machine learning algorithms showed that factors such as tobacco use, younger age, open fracture, multi-trauma, operative treatment, as well as male sex heightened the risk of VTE. In contrast, certain factors such as vitamin D supplementation had negative correlation with VTE. Machine learning algorithms acted in a more complex manner and incorporated more factors in decision-making compared to conventional methods. External validation using larger and more granular datasets as well as using the algorithms in trial modes (shadow modes) are needed to build trust in this algorithm to assist clinicians in predicting/preventing VTE after foot and ankle surgeries.

ANTITUBERCULOSIS CHEMOPROPHYLAXIS IN TOTAL HIP PROSTHESIS ON COXALGIA SEQUELAE (ABOUT THREE CASES)

Osteoarticular tuberculosis (OAT) is defined as the set of pathological manifestations secondary to damage to the bone and joint structures of the musculoskeletal system by the Kochs bacillus (BK). These lesions can lead in the long term to very important functional sequelae due to damage to the hip. The total hip replacement (THR), by restoring mobility and indolence, will transform the life of these patients. The objectif of this study is to evaluate the usefulness of antitubercular chemoprophylaxis after a total hip replacement for coxalgia sequelae. This work consists in to carry out a retrospective study of three cases of THP realise on sequelae of coxalgia in the department of orthopedic of the Mohammed VI University Hospital of Oujda between September 2015 and December 2021.Our series includes four patients, two women and two men. The average age at the time of surgery was 54 years. The Postel Merle dAubigné scoring system was used to evaluate the condition of the hip before and after surgery. All patients had a history of coxalgia treated with antibacillaries. All patients had Martini stage 4. The Moore posterolateral approach was performed in all patients. The THP was cemented in two cases and uncemented in one case and dual mobility in all patients. No patient was put on postoperative anti-tubercular therapy. The clinical and radiological results for the four patients, after a mean follow-up of 27 months, were satisfactory in the majority of cases. In the case of advanced bone destruction with very poorly tolerated functional repercussions in a mature subject, total arthroplasty remains the treatment of choice for the sequelae of coxalgia without recourse to postoperative chemoprophylaxis.

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

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. 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. 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 >20g/L fall in hemoglobin. 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. In high VTE risk patients undergoing major abdominal surgery, chemoprophylaxis commenced postoperatively reduces bleeding risk without affecting clinical VTE risk.

P144. The effect of operative duration on postoperative VTE rates in spinal surgery

<h3>BACKGROUND CONTEXT</h3> The relationship between operative duration and its effect on postoperative venous thromboembolism (VTE) remains unclear in spine surgery. Previous studies have been limited in cohort size or have lacked adequate variability of surgical duration to determine the extent of effect surgery length has on VTE rates. Information regarding patient demographics and the effect of surgical durations on VTE are critical to establish appropriate guidelines for determining which patients could benefit from postoperative chemoprophylaxis. <h3>PURPOSE</h3> To determine the effect of operative duration on postoperative VTE rates in patients undergoing elective thoracolumbar spinal procedures. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Patients >18 years of age who underwent thoracolumbar spinal fusion between 2007-2021 were retrospectively identified. A 10:1 propensity match incorporating patient demographics and surgical characteristics was conducted to match and compare patients for postoperative VTE events. <h3>OUTCOME MEASURES</h3> Postoperative VTE events, cut-to-close duration, prior history of clots, Oswestry Disability Index (ODI), Mental (MCS-12) and Physical (PCS-12) Component Summary of the Short-Form 12, visual analog scale (VAS) Back, VAS Leg. <h3>METHODS</h3> A structured query language (SQL) search was used to identify patients who underwent a thoracolumbar surgery and had a postoperative VTE. Only patients with deep VTEs were included. Demographics, surgical characteristics and patient reported outcome measures (PROMs) were collected from the electronic medical record. Patients were categorized into a VTE and non-VTE group. Categorical comparisons were analyzed using Pearson chi-square analysis or Fisher's Exact test. Continuous variables were analyzed using independent samples t-test or Mann-Whitney U test. A binary logistic regression was then performed to determine if cut-to-close duration was a predictor of increased postoperative VTE events—controlling for demographics and a history of clots. A receiver operating characteristic (ROC) curve using Youden's index was created to determine a "cutoff" time for predicting increased likelihood of a VTE based on surgical duration. <h3>RESULTS</h3> A total of 1,456 patients (122 VTE, 1,334 non-VTE) were included. The VTE group was younger (61.5 vs 65.5, p<0.001), predominantly male (60.8% vs 44.5%, p=0.001), experienced a previous VTE (15.6% vs 2.92%, p<0.001) and had higher cut-to-close time (304 mins vs 209 mins, p<0.001). However, there was no difference in CCI between groups (1.08 vs 0.66, p=0.119). When evaluating PROMs, the VTE group had worse 1-year postoperative minus preoperative (∆) ODI (-11.79 vs -21.99, p=0.039), ∆PCS-12 (4.30 vs 8.52, p=0.045), and ∆VAS Leg (-1.41 vs -4.08, p=0.001). Operative duration was an independent predictor of increased postoperative VTE rates on bivariate regression analysis (β=0.01, p<0.001). When evaluating the ROC, a cutoff time of 245 mins was identified (AUC [95% CI] = 0.672 [0.615 – 0.728]) as an optimal predictor of increased risk for a VTE. <h3>CONCLUSIONS</h3> A history of a prior VTE was associated with greater VTE rates during elective thoracolumbar surgery. Patients with a VTE had worse 1-year ∆ODI, ∆PCS-12, and ∆VAS Leg indicating that patients have worse overall improvement after VTE development, even after the VTE has been treated. Additionally, a higher operative duration is an independent risk factor for postoperative VTE. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Cost-Effective Modeling of Thromboembolic Chemoprophylaxis for Total Ankle Arthroplasty.

Background:Symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) can cause substantial morbidity and mortality. To prevent this complication, surgeons often prescribe postoperative chemoprophylaxis. However, much controversy exists regarding the efficacy of chemoprophylaxis because of the limited studies exploring its use. Furthermore, even less is known about its cost-effectiveness. Therefore, this study sought to determine the cost-effectiveness of commonly prescribed chemoprophylactic agents using a break-even analysis economic model.Methods:The literature was searched, and an online database was used to identify patients who developed a symptomatic VTE after undergoing TAA. Our institutional records were used to estimate the cost of treating a symptomatic VTE, and an online drug database was used to obtain the cost of commonly prescribed chemoprophylactic agents. A break-even analysis was then performed to determine the final break-even rate necessary to make a drug cost-effective.Results:The low and high rates of symptomatic VTE were determined to be 0.46% and 9.8%. From 2011 to 2021, a total of 3455 patients underwent total ankle arthroplasty. Of these patients, 16 developed a postoperative symptomatic VTE (1.01%). Aspirin 81 mg was cost-effective if the initial symptomatic VTE rates decreased by an absolute risk reduction (ARR) of 0.0003% (NNT = 31 357). Aspirin 325 mg was also cost-effective if the initial rates decreased by an ARR 0.02% (NNT = 5807). Likewise, warfarin (5 mg) was cost-effective at all initial rates with an ARR of 0.02% (NNT = 4480). In contrast, enoxaparin (40 mg) and rivaroxaban (20 mg) were only cost-effective at higher initial symptomatic VTE rates with ARRs of 1.48% (NNT = 68) and 5.36% (NNT = 19). Additional analyses demonstrated that enoxaparin (40 mg) and rivaroxaban (20 mg) become cost-effective when costs of treating a symptomatic VTE are higher than our estimates.Conclusion:Chemoprophylaxis following TAA can be cost-effective. A tailored approach to VTE prophylaxis with cost-effectiveness in mind may be beneficial to the patient and health system.

Venous Thromboembolic Events are Exceedingly Rare in Spinal Fusion for Adolescent Idiopathic Scoliosis.

Review of health care record database and determination of population statistics. The purpose of this study was to quantify the incidence of clinically significant venous thromboembolic (VTE) events in patients undergoing spinal fusion surgery for adolescent idiopathic scoliosis (AIS) and to identify risk factors for VTE. VTE is a serious complication that can cause disability and even death following surgery. Incidence of VTE following AIS surgery has not been well studied; the use of a national database allows the assessment of rare, yet important complications. The PearlDiver Database was used to identify AIS patients who underwent primary instrumented spinal fusion between 2010 and 2020. Patient records were cross-referenced for documented VTEs within 30 and 90 postoperative days. Patients with nonidiopathic scoliosis were excluded. Logistic regression was used to evaluate risk factors for correlation with VTE events. Thirty-eight of 11,775 (0.323%) patients undergoing surgery for AIS developed a VTE complication within 90 postoperative days. Hypercoagulability [odds ratio (OR)=13.50, P <0.0001], spinal fusion involving 13+ vertebral levels (OR=2.61, P <0.0001), obesity (OR=1.30, P <0.005), and older (15-18 y) compared with younger adolescence (10-14 y) (OR=2.12, P <0.0001) were associated with VTE. Seven of 38 (18.4%) patients with a diagnosed thrombophilia experienced VTE. The incidence of clinically significant VTEs in pediatric patients following spinal fusion surgery for AIS is low with an incidence of 0.323%. Postoperative chemoprophylaxis in the general pediatric population is not indicated. Patients with obesity, those undergoing spinal fusion of 13 or more vertebrae, and adolescents 15-18 years old were found to have higher but still small risk of VTE following surgery. Further prospective studies are needed to validate the risk profile of patients with hypercoagulability and establish clinical guidelines for use of postoperative chemoprophylaxis in this cohort. Level III.

Chemothromboprophylaxis in varicose vein surgery: a systematic review.

Venous thromboembolism (VTE) is a possible complication after varicose vein surgery, reported after both open and endovascular interventions. Nonetheless, there are no internationally accepted recommendations regarding postoperative VTE prevention strategies, with some authors advocating for its use, while others recommend against it. This study aims to systematically review current evidence on the efficacy and safety of chemothromboprophylactic strategies after varicose vein surgery. A literature search was performed on the MEDLINE, Scopus, SciELO and Web of Science databases, which returned 532 studies. Ten studies were included. Data were extracted using piloted forms. A total of 6929 patients were included for analysis, out of which 70.4% were treated by open surgery (N.=4878) and 29.6% by endovenous procedures (N.=2051; 79.1% EVLA; 20.9% RFA). VTE chemothromboprophylaxis was performed in 76.3% of the patients (N.=5284), from which 62.5% were treated by open surgery (N.=3301) and 37.5% by endovenous interventions (N.=1983). Among those treated by open surgery, reported deep venous thrombosis (DVT) rates ranged between 0-6.25%, while pulmonary embolism (PE) was reported in 0-0.07% of the cases. Regarding endovenous interventions, EHIT and DVT rates ranged between 0-2.5% and 0-0.9%, respectively, with no cases of PE described. The remaining 23.7% of the patients did not underwent VTE chemothromboprophylaxis (N.=1645), with DVT and PE rates after open surgery ranging between 0-5.17% and 0-1.48%, respectively. Only one study reported thrombotic complications after endovenous interventions in this subgroup of patients, with postoperative EHIT rates of 7.3%, and no information regarding PE or DVT. Bleeding complications were higher in patients undergoing chemothromboprophylaxis (0-10.2%) when compared to those who did not (0-0.18%), and were more frequent after endovenous interventions (0-10.2% versus 0-0.75% after open surgery). VTE is a possible complication after both open and endovascular varicose vein procedures, although overall VTE complications occur less frequently after endovascular interventions. There's a clear heterogeneity regarding peri and postoperative chemoprophylaxis regimens used. Further studies are required to stratify risk factors and indications for chemothromboprophylaxis after varicose vein surgery.

Earlier functional recovery and discharge from hospital for THA patients operated on via direct superior compared to standard posterior approach: a retrospective frequency-matched case-control study.

The direct superior hip approach (DSA) has been less researched than other approaches in the literature. We retrospectively compared the early postoperative and functional outcomes of patients with hip osteoarthritis undergoing total hip arthroplasty (THA) via DSA with a matched control group using a standard posterior approach (SPA). The DSA group comprised 100 THAs performed via DSA by a senior surgeon between January 2018 and May 2019. Patients with primary osteoarthritis and ASA score ⩽3 who were eligible for surgery were included. The DSA group was compared to a matched cohort of 100 patients operated on with a SPA in the same period by another chief surgeon. Patients were matched for age, sex, and ASA score. All patients received the same postoperative chemoprophylaxis, pain management and physiotherapy. 2 independent attending arthroplasty surgeons assessed the incision length, operative time, blood loss, hospital stay, and complications. VAS, HHS, and HOOS scores were also evaluated for a year postoperatively. Mean incision length and hospital stay were significantly lower in the DSA group. DSA patients had non-significantly lower intraoperative blood loss, transfusion needs, and postoperative pain than SPA patients. Mean operation time and complication rate did not differ between groups. The DSA group demonstrated significantly greater functional scores than the SPA group at the first postoperative month. No differences in scores were recorded following the third month. The DSA approach may provide earlier functional recovery and hospital discharge for THA patients compared with SPA. DSA was equivalent to SPA concerning pain and blood loss, showing minimal complication rates.

Early Versus Postoperative Chemical Thromboprophylaxis Is Associated with Increased Bleeding Risk Following Abdominal Visceral Resections: a Multicenter Cohort Study

BackgroundAbdominal visceral resections incur relatively higher rates of postoperative bleeding and venous thromboembolism (VTE). While guidelines recommend the use of perioperative chemical thromboprophylaxis, the most appropriate time for its initiation is unknown. Here, we investigated whether early (before skin closure) versus postoperative commencement of chemoprophylaxis affected VTE and bleeding rates following abdominal visceral resection. MethodsRetrospective review of all elective abdominal visceral resections undertaken between January 1, 2018, and June 30, 2019, across four tertiary-referral hospitals. Major bleeding was defined as the need for blood transfusion, reintervention, or > 20 g/L fall in hemoglobin from baseline. Clinical VTE was defined as imaging-proven symptomatic disease < 30 days post-surgery. ResultsA total of 945 cases were analyzed. Chemoprophylaxis was given early in 265 (28.0%) patients and postoperatively in 680 (72.0%) patients. Mean chemoprophylaxis exposure doses were similar between the two groups. Clinical VTE developed in 14 (1.5%) patients and was unrelated to chemoprophylaxis timing. Postoperative bleeding occurred in 71 (7.5%) patients, with 57 (80.3%) major bleeds, requiring blood transfusion in 48 (67.6%) cases and reintervention in 31 (43.7%) cases. Bleeding extended length-of-stay (median (IQR), 12 (7–27) versus 7 (5–11) days, p < 0.001). Importantly, compared to postoperative chemoprophylaxis, early administration significantly increased the risk of bleeding (10.6% versus 6.3%, RR 1.45, 95% CI 1.05–1.93, p = 0.038) and independently predicted its occurrence. ConclusionsThe risk of bleeding following elective abdominal visceral resections is substantial and is higher than the risk of clinical VTE. Compared with early chemoprophylaxis, postoperative initiation reduces bleeding risk without an increased risk of clinical VTE.

Venous thromboembolism chemical prophylaxis after endoscopic trans-sphenoidal pituitary surgery

PurposeThere is no compelling outcome data or clear guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using low molecular weight heparin (chemoprophylaxis) in patients undergoing pituitary surgery. Here we describe our experience of early chemoprophylaxis (post-operative day 1) following trans-sphenoidal pituitary surgery.MethodsSingle-centre review of a prospective surgical database and VTE records. Adults undergoing first time trans-sphenoidal pituitary surgery were included (2009–2018). VTE was defined as either deep vein thrombosis and/or pulmonary embolism within 3 months of surgery. Postoperative haematomas were those associated with a clinical deterioration together with radiological evidence.Results651 Patients included with a median age of 55 years (range 16–86 years). Most (99%) patients underwent trans-sphenoidal surgery using a standard endoscopic single nostril or bi-nostril trans-sphenoidal technique. More than three quarters had pituitary adenomas (n = 520, 80%). Postoperative chemoprophylaxis to prevent VTE was administered in 478 patients (73%). Chemoprophylaxis was initiated at a median of 1 day post-procedure (range 1–5 days postoperatively; 92% on postoperative day 1). Tinzaparin was used in 465/478 patients (97%) and enoxaparin was used in 14/478 (3%). There were no cases of VTE, even in 78 ACTH-dependent Cushing’s disease patients. Six patients (1%) developed postoperative haematomas. Chemoprophylaxis was not associated with a significantly higher rate of postoperative haematoma formation (Fisher’s Exact, p = 0.99) or epistaxis (Fisher’s Exact, p > 0.99).ConclusionsChemoprophylaxis after trans-sphenoidal pituitary surgery on post-operative day 1 is a safe strategy to reduce the risk of VTE without significantly increasing the risk of postoperative bleeding events.

Multimodal Thromboprophylaxis in Patients With a History of Venous Thromboembolism Undergoing Primary and Revision Knee Arthroplasty.

Background: Patients with a history of venous thromboembolism (VTE) undergoing total knee arthroplasty (TKA) are at a high risk of postoperative VTE. Purpose: In this high-risk population, we sought to evaluate the safety and efficacy of multimodal thromboprophylaxis. The regimen consisted of discontinuation of procoagulant medications, VTE risk stratification, regional anesthesia, rapid mobilization, perioperative use of pneumatic compression devices, vigorous ankle dorsiflexion during the recovery period, and chemoprophylaxis tailored to the patient's risk of VTE. Methods: We conducted a retrospective chart review of 141 consecutive patients with a history of VTE who underwent 177 elective TKA procedures between 2005 and 2019 by 2 arthroplasty surgeons at a single institution. The patients had a history of deep venous thrombosis (DVT) (n = 127; 72%), pulmonary embolism (PE) (n = 20; 11%), or both (n = 30; 17%). Postoperative chemoprophylaxis included aspirin (n = 20; 11%), anticoagulation (n = 135; 77%), or a combination of aspirin and anticoagulation (n = 21; 12%). Complications within 120 days, including VTE events, wound complications, bleeding, and unplanned readmissions, were recorded, as was 1-year mortality. Results: Five patients (2.8%) developed symptomatic DVT (3 distal, 2 proximal), and 4 patients (2.3%) developed symptomatic PE. The most common postdischarge complications were wound infection (n = 6; 3.4%) and stiffness requiring manipulation under anesthesia (n = 5; 2.8%). There was 1 emergency room visit and 13 unplanned readmissions; 3 patients developed intra-articular hematomas or prolonged wound drainage and recovered uneventfully. All patients were alive 1 year after surgery. Conclusion: The findings of this retrospective study suggest that multimodal prophylaxis may be safe and effective in patients with a history of VTE undergoing primary and revision TKA. More rigorous study is warranted.