Perioperative Anticoagulation Management in Spine Surgery: Initial Findings From the AO Spine Anticoagulation Global Survey

Revisiting Anticoagulation in Spine Surgery: Balancing Venous Thromboembolic Events and Epidural Hematoma

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Venous thromboembolic events (VTE) and post-operative epidural hematoma (EDH) are significant complications after spine surgery. Guidelines for chemoprophylaxis are controversial and variability amongst surgeons remains. The objective of this study was to establish the incidence of clinical VTE and EDH at our institution and evaluate the association of chemoprophylaxis with clinical VTE and EDH.

METHODS

We conducted a retrospective cohort study of patients undergoing spine surgery at a high-volume tertiary care center in Seattle, WA between January 2016 and December 2019. The Premier Health Care Database and Agency for Healthcare Research and Quality (AHRQ) patient indicators PSI-9 (Perioperative hemorrhage and hematoma) and PSI-12(Perioperative PE or DVT) were used to identify patients experiencing VTE and/or post-operative EDH. The primary outcome was the incidence of clinical VTE and EDH in post-operative spine patients. Secondary outcomes included the association of chemoprophylaxis with clinical VTE and EDH.

RESULTS

From 2016 to 2019, 4587 patients underwent spine surgery, totaling 4764 hospital stays. The incidence of clinical VTE was .21% (10/4764) and the incidence of EDH was .10% (5/4764). Most hemorrhages occurred prior to the initiation of chemoprophylaxis. One patient with EDH received chemoprophylaxis prior to hemorrhage.

CONCLUSIONS

The rate of post-operative clinical VTE and EDH in spine surgery is low. Despite early initiation of chemoprophylaxis after major spine surgery we did not appreciate a high rate of EDH. We attribute our low rate of clinical VTE to multimodal prophylaxis with SCDs, early mobilization and chemoprophylaxis on post-operative day 1.

Lumbar Fusions in Patients with Sickle Cell Disease: A Propensity-Matched Analysis of Postoperative Complications

OBJECTIVE

The present study compares postoperative outcomes between patients with and without sickle cell disease (SCD) undergoing 1-to 3-level lumbar spinal fusion for degenerative pathologies.

METHODS

Patients who underwent 1-to 3-level lumbar spinal fusion for degenerative pathologies from 2010 to 2021 were identified using the PearlDiver database. Patients were separated into 1) SCD and 2) non-SCD groups and were propensity-matched 1:1 for age, sex, Elixhauser Comorbidity Index, surgical approach, and various comorbidities. Complications were separately analyzed by single- and multilevel procedures using chi-squared and Mann-Whitney U testing.

RESULTS

Propensity-score matching identified 1934 SCD and non-SCD patients who underwent single-level fusion and 2094 SCD and non-SCD patients who underwent multilevel fusion. Across single-level fusions, those with SCD had a significantly higher risk of neurovascular compromise (P < 0.001), venous thromboembolism (P = 0.004), pneumonia (P = 0.032), urinary tract infections (P = 0.001), and greater postoperative opioid usage out to 12 months (P = 0.018). Across multilevel fusions, SCD carried higher risk for neurovascular compromise (P < 0.001), pneumonia (P = 0.010), and urinary tract infections (P < 0.001). All SCD patients had significantly higher opioid use at 1 month (P = 0.001) and at 6 months (P = 0.009) postoperatively.

CONCLUSIONS

Patients with SCD undergoing lumbar spinal fusion demonstrate higher risks for coagulopathic, ischemic, and infectious-related complications, as well as long-term postoperative opioid use. Awareness of the unique complication profile in SCD patients may help guide surgeons in refining perioperative management strategies to optimize outcomes in patients with SCD.

Complications of Venous Thromboembolism Chemoprophylaxis in Lumbar Laminectomy With and Without Fusion

BACKGROUND

The benefit of chemoprophylaxis (CPX) agents in preventing venous thromboembolism must be weighed against potential risks. Current literature regarding the efficacy of CPX after laminectomies with or without fusion is limited, with no clear consensus to inform guidelines.

OBJECTIVE

This study evaluated the association between CPX and surgical complications after lumbar laminectomy with and without fusion.

STUDY DESIGN

Retrospective study of patients at a single large academic institution.

METHODS

The medical records of patients who underwent lumbar laminectomies with or without lumbar fusion from 2018 to 2020 were reviewed for demographics, surgical characteristics, CPX agents, postoperative complications, epidural hematomas, and wound drainage. Patients receiving CPX (n = 316) were compared with patients not receiving CPX (n = 316) via t test following propensity score matching, and patients on CPX were further stratified by fusion status.

RESULTS

The CPX group had higher body mass index and American Society of Anesthesiologists grades. Rates of venous thromboembolism, epidural hematomas, infections, postoperative incision and drainage, transfusions, wound dehiscence, and reoperation were not associated with CPX. Moist dressings were more frequent, and average days of drain duration were longer with CPX. Overall postoperative complication rate and length of stay (LOS) were greater with CPX. The fusion subgroup had a lower Charlson Comorbidity Index, had a lower American Society of Anesthesiologists grade, was younger, had more women, and underwent more minimally invasive laminectomies. While estimated blood loss, operative times, and LOS were significantly greater in the fusion group, there was no difference in rate of intraoperative and postoperative complications.

CONCLUSION

CPX after lumbar laminectomies with or without fusion was not associated with increased rates of epidural hematomas, wound complications, or reoperation. Patients receiving CPX had more postoperative cardiac complications, but it is possible that surgeons were more likely to prescribe CPX for higher-risk patients. They also had higher rates of ileus and moist dressings, greater LOS, and longer length of drain duration. Patients who underwent lumbar laminectomy with fusion on CPX tended to be lower risk yet incurred greater blood loss, operative times, LOS, cardiac complications, and hematomas/seromas than patients not undergoing fusion.

CLINICAL RELEVANCE

This retrospective study compared surgical complications of lumbar laminectomies in patients who received chemoprophylaxis vs patients who did not. Chemoprophylaxis was not associated with increased rates of epidural hematomas, wound complications, or reoperation, but it was associated with higher rates of postoperative cardiac complications and ileus.

LEVEL OF EVIDENCE: 3

Chemical prophylaxis and venous thromboembolism following elective spinal surgery: A systematic review and meta-analysis

Background

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a potentially devastating complication after surgery. Spine surgery is associated with an increased risk of postoperative bleeding, such as spinal epidural hematomas (SEH), which complicates the use of anticoagulation. Despite this dilemma, there is a lack of consensus around perioperative VTE prophylaxis. This systematic review investigates the relationship between chemoprophylaxis and the incidence rates of VTE and SEH in the elective spine surgical population.

Methods

A comprehensive literature search was performed using PubMed, Embase, and Cochrane databases to identify studies published after 2,000 that compared VTE chemoprophylaxis use in elective spine surgery. Studies involving patients aged < 18 years or with known trauma, cancer, or spinal cord injuries were excluded. Pooled incidence rates of VTE and SEH were calculated for all eligible studies, and meta-analyses were performed to assess the relationship between chemoprophylaxis and the incidences of VTE and SEH.

Results

Nineteen studies met our eligibility criteria, comprising a total of 220,932 patients. The overall pooled incidence of VTE was 3.2%, including 3.3% for DVT and 0.4% for PE. A comparison of VTE incidence between patients that did and did not receive chemoprophylaxis was not statistically significant (OR 0.97, p=.95, 95% CI 0.43-2.19). The overall pooled incidence of SEH was 0.4%, and there was also no significant difference between patients that did and did not receive chemoprophylaxis (OR 1.57, p=.06, 95% CI 0.99-2.50).

Conclusions

The use of perioperative chemoprophylaxis may not significantly alter rates of VTE or SEH in the elective spine surgery population. This review highlights the need for additional randomized controlled trials to better define the risks and benefits of specific chemoprophylactic protocols in various subpopulations of elective spine surgery.

Chemoprophylactic Anticoagulation After Spine Surgery Does Not Increase Epidural Hematoma Risk: A Propensity-matched Analysis

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To calculate the magnitude of any increased risk of epidural hematoma (EDH) associated with chemoprophylactic anticoagulation (chemoprophylaxis), if any.

SUMMARY OF BACKGROUND DATA

Chemoprophylaxis for the prevention of venous thromboembolic events may be associated with an increased risk of EDH after spine surgery.

MATERIALS AND METHODS

A total of 6869 consecutive spine surgeries performed at our institution were identified, and clinical and demographic data were collected. We identified cases in which symptomatic EDHs were evacuated within 30 days postoperatively. Patients receiving chemoprophylaxis and controls were matched using K-nearest neighbor propensity score matching to calculate the effect of anticoagulation on the rate of postoperative EDH.

RESULTS

After propensity score matching, 1071 patients who received chemoprophylaxis were matched to 1585 controls. Propensity scores were well balanced between populations (Rubin B=20.6, Rubin R=1.05), and an 89.6% reduction in bias was achieved, with a remaining mean bias of 3.2%. The effect of chemoprophylaxis on EDH was insignificant ( P =0.294). Symptomatic EDH was independently associated with having a transfusion [odds ratio (OR)=7.30 (1.15, 46.20), P =0.035], having thoracic-level surgery [OR=41.19 (3.75, 452.4), P =0.002], and increasing body mass index [OR=1.44 (1.04, 1.98), P =0.028] but was not associated with chemoprophylaxis. Five out of 13 patients who developed EDH (38.5%) were receiving some form of anticoagulation, including 1 patient on therapeutic anticoagulation, 1 concurrently on aspirin and chemoprophylaxis, and 2 who were also found to have developed thrombocytopenia postoperatively. The median time on anticoagulation before EDH was 8.1 days. A higher proportion of patients who developed EDH also developed venous thromboembolic events than the general population [38.5% vs. 2.4%, OR=25.34 (9.226, 79.68), P <0.0001], and 1 EDH patient died from pulmonary embolism while off chemoprophylaxis.

CONCLUSIONS

Chemoprophylactic anticoagulation did not cause an increase in the rate of spinal EDH in our patient population.

Risk factors for in-hospital mortality in geriatric patients aged 80 and older with axis fractures: a nationwide, cross-sectional analysis of concomitant injuries, comorbidities, and treatment strategies in 10,077 cases

PURPOSE

To investigate the association between treatment, comorbidities, concomitant injuries, and procedures with in-hospital mortality in patients aged 80 years or older with axis fractures.

METHODS

Data were extracted from the German InEK (Institut für das Entgeltsystem im Krankenhaus) GmbH database (2019-2021) for patients aged 80 years or older with axis fractures and the in-hospital mortality rate was calculated. Differences in comorbidities and concomitant diseases and injuries were analyzed using the Chi-square test. In surgically treated patients, odds ratios (OR) with 95% confidence intervals (95% CI) were used to analyze potential risk factors for in-hospital mortality.

RESULTS

Among 10,077 patients, the in-hospital mortality rate was 8.4%, with no significant difference between surgically (9.4%) and non-surgically treated patients (7.9%; p = 0.103). The most common comorbidities were essential hypertension (67.3%), atrial fibrillation (28.2%), and chronic kidney disease (23.3%), while the most common concomitant injuries were head and face wounds (25.9%), concussions (12.8%), and atlas fractures (11.6%). In surgically treated patients, spinal cord injury (OR = 4.62, 95% CI: 2.23-9.58), acute renal failure (OR = 3.20, 95% CI: 2.26-4.53), and acute bleeding anemia (OR = 2.06, 95% CI: 1.64-2.59) were associated with increased in-hospital mortality (all p < 0.01). Screw-rod-system fixation of one segment (OR = 0.74, 95% CI: 0.56-0.97) and intraoperative navigation (OR = 0.45, 95% CI: 0.16-0.71) were identified as potential protective factors (both p < 0.05).

CONCLUSION

Comprehensive geriatric assessment and optimization of comorbidities during treatment are crucial. The indication for surgical treatment must be carefully individualized. Future studies should focus on the choice of surgical technique, perioperative blood management, and intraoperative navigation as potential protective factors.

Risk factors for spinal subdural hematoma after minimally invasive transforaminal lumbar Interbody Fusion (MI-TLIF): a multivariate analysis

BACKGROUND

Spinal subdural hematoma (SSH) is a rare cause of compression of the neutral elements of the spinal cord. However, little is known about the presentation of acute SSH after lumbar spine surgery. The reason for this may be that symptomatic SSH occurs rarely and is not given enough attention by spine surgeons. Currently, the decision to perform MRI postoperatively is more dependent on surgeon preference; therefore, no high-quality studies have been published. Our team reports our experience in the diagnosis and management of SSH after lumbar decompression and fusion surgery.

METHODS

We retrospectively studied 215 patients who underwent routine MRI following minimal invasive transforaminal lumbar interbody fusion (MI-TLIF) between 2020-01-01 and 2022-06-30. The patients were divided into SSH group (17 cases) and non-SSH group (198 cases) according to the occurrence of SSH. Univariate analysis and multivariate logistic regression analysis were performed to identify relevant risk factors that increase the risk of SSH postoperatively.

RESULTS

None of the patients presented with serious neurologic symptoms, such as lower extremity paralysis or cauda equina syndrome that required emergency hematoma debridement. SSH was found in 17 (7.9%) patients and non-SSH in 198 (92.1%). Factors affecting SSH were presence of hypertension, presence of diabetes and postoperative anticoagulant therapy. The significantly independent risk factor of postoperative SSH were diabetes (P = 0.008, OR: 6.988) and postoperative anticoagulant therapy (P = 0.003, OR: 8.808).

CONCLUSIONS

SSH after MI-TLIF is not a rare condition, with generally no requirement of emergency evacuation. Comprehensive anti-symptomatic treatment could achieve satisfactory results. Diabetes mellitus and postoperative anticoagulant therapy are independent risk factors for SSH. Spine surgeons should hold applicability of the use of anticoagulants after lumbar surgery.

Using Machine Learning (ML) Models to Predict Risk of Venous Thromboembolism (VTE) Following Spine Surgery

STUDY DESIGN

A retrospective cohort study.

OBJECTIVES

Venous thromboembolism (VTE) is a potentially high-risk complication for patients undergoing spine surgery. Although guidelines for assessing VTE risk in this population have been established, development of new techniques that target different aspects of the medical history may prove to be of further utility. The goal of this study was to develop a predictive machine learning (ML) model to identify nontraditional risk factors for predicting VTE in spine surgery patients.

SUMMARY OF BACKGROUND DATA

A cohort of 63 patients was identified who had undergone spine surgery at a single center from 2015 to 2021. Thirty-one patients had a confirmed VTE, while 32 had no VTE. A total of 113 attributes were defined and collected via chart review. Attribute categories included demographics, medications, labs, past medical history, operative history, and VTE diagnosis.

METHODS

The Waikato Environment for Knowledge Analysis (WEKA) software was used in creating and evaluating the ML models. Six classifier models were tested with 10-fold cross-validation and statistically evaluated using t tests.

RESULTS

Comparing the predictive ML models to the control model (ZeroR), all predictive models were significantly better than the control model at predicting VTE risk, based on the 113 attributes ( P <0.001). The Random Forest model had the highest accuracy of 88.89% with a positive predictive value of 93.75%. The Simple Logistic algorithm had an accuracy of 84.13% and defined risk attributes to include calcium and phosphate laboratory values, history of cardiac comorbidity, history of previous VTE, anesthesia time, selective serotonin reuptake inhibitor use, antibiotic use, and antihistamine use. The J48 model had an accuracy of 80.95% and it defined hemoglobin laboratory values, anesthesia time, beta-blocker use, dopamine agonist use, history of cancer, and Medicare use as potential VTE risk factors.

CONCLUSION

Further development of these tools may provide high diagnostic value and may guide chemoprophylaxis treatment in this setting of high-risk patients.

Does the choice of chemoprophylaxis affect the prevention of deep vein thrombosis in lumbar fusion surgery? A systematic review of the literature

INTRODUCTION

To date, the available guidance on venous thromboembolism (VTE) prevention in elective lumbar fusion surgery is largely open to surgeon interpretation and preference without any specific suggested chemoprophylactic regimen.

RESEARCH QUESTION

This study aimed to comparatively analyze the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) with the use of commonly employed chemoprophylactic agents such as unfractionated heparin (UH) and low molecular weight heparin (LMWH) in lumbar fusion surgery.

MATERIAL AND METHODS

An independent systematic review of four scientific databases (PubMed, Scopus, clinicaltrials.gov, Web of Science) was performed to identify relevant articles as per the preferred reporting in systematic reviews and meta-analysis (PRISMA) guidelines. Studies reporting on DVT/PE outcomes of lumbar fusion surgery in adult patients with UH or LMWH chemoprophylaxis were included for analysis. Analysis was performed using the Stata software.

RESULTS

Twelve studies with 8495 patients were included in the analysis. A single-arm meta-analysis of the included studies found a DVT incidence of 14% (95%CI [8%-20%]) and 1% (95%CI [-6% - 8%]) with LMWH and UH respectively. Both the chemoprophylaxis agents prevented PE with a noted incidence of 0% (95%CI [0%-0.1%]) and 0% (95%CI [0%-1%]) with LMWH and UH respectively. The risk of bleeding-related complications with the usage of LMWH and UH was 0% (95% CI [0.0%-0.30%]) and 3% (95% CI [0.3%-5%]) respectively.

DISCUSSION AND CONCLUSION

Both LMWH and UH reduces the overall incidence of DVT/PE, but there is a paucity of evidence analyzing the comparative effectiveness of the chemoprophylaxis regimens in lumbar fusion procedures. The heterogeneity in data prevents any conclusions, as there remains an evidence gap. We recommend future high-quality randomized controlled trials to investigate in this regard to help develop recommendations on thromboprophylaxis usage.

Thromboembolic prophylaxis in spine surgery: an analysis of ChatGPT recommendations

BACKGROUND CONTEXT

Venous thromboembolism is a negative outcome of elective spine surgery. However, the use of thromboembolic chemoprophylaxis in this patient population is controversial due to the possible increased risk of epidural hematoma. ChatGPT is an artificial intelligence model which may be able to generate recommendations for thromboembolic prophylaxis in spine surgery.

PURPOSE

To evaluate the accuracy of ChatGPT recommendations for thromboembolic prophylaxis in spine surgery.

STUDY DESIGN/SETTING

Comparative analysis.

PATIENT SAMPLE

None.

OUTCOME MEASURES

Accuracy, over-conclusiveness, supplemental, and incompleteness of ChatGPT responses compared to the North American Spine Society (NASS) clinical guidelines.

METHODS

ChatGPT was prompted with questions from the 2009 NASS clinical guidelines for antithrombotic therapies and evaluated for concordance with the clinical guidelines. ChatGPT-3.5 responses were obtained on March 5, 2023, and ChatGPT-4.0 responses were obtained on April 7, 2023. A ChatGPT response was classified as accurate if it did not contradict the clinical guideline. Three additional categories were created to further evaluate the ChatGPT responses in comparison to the NASS guidelines: over-conclusiveness, supplementary, and incompleteness. ChatGPT was classified as over-conclusive if it made a recommendation where the NASS guideline did not provide one. ChatGPT was classified as supplementary if it included additional relevant information not specified by the NASS guideline. ChatGPT was classified as incomplete if it failed to provide relevant information included in the NASS guideline.

RESULTS

Twelve clinical guidelines were evaluated in total. Compared to the NASS clinical guidelines, ChatGPT-3.5 was accurate in 4 (33%) of its responses while ChatGPT-4.0 was accurate in 11 (92%) responses. ChatGPT-3.5 was over-conclusive in 6 (50%) of its responses while ChatGPT-4.0 was over-conclusive in 1 (8%) response. ChatGPT-3.5 provided supplemental information in 8 (67%) of its responses, and ChatGPT-4.0 provided supplemental information in 11 (92%) responses. Four (33%) responses from ChatGPT-3.5 were incomplete, and 4 (33%) responses from ChatGPT-4.0 were incomplete.

CONCLUSIONS

ChatGPT was able to provide recommendations for thromboembolic prophylaxis with reasonable accuracy. ChatGPT-3.5 tended to cite nonexistent sources and was more likely to give specific recommendations while ChatGPT-4.0 was more conservative in its answers. As ChatGPT is continuously updated, further validation is needed before it can be used as a guideline for clinical practice.

Research Practices and Needs Among Spine Surgeons Worldwide

OBJECTIVE

Resource allocation to research activities is challenging and there is limited evidence to justify decisions. Members of AO Spine were surveyed to understand the research practices and needs of spine surgeons worldwide.

METHODS

An 84-item survey was distributed to the AO Spine community in September of 2020. Respondent demographics and insights regarding research registries, training and education, mentorship, grants and financial support, and future directions were collected. Responses were anonymous and compared among regions.

RESULTS

A total of 333 spine surgeons representing all geographic regions responded; 52.3% were affiliated with an academic/university hospital, 91.0% conducted clinical research, and 60.9% had 5+ years of research experience. There was heterogeneity among research practices and needs across regions. North American respondents had more research experience (P = .023), began conducting research early on (P < .001), had an undergraduate science degree (P < .001), and were more likely to have access to a research coordinator or support staff (P = .042) compared to other regions. While all regions expressed having the same challenges in conducting research, Latin America, and Middle East/Northern Africa respondents were less encouraged to do research (P < .001). Despite regional differences, there was global support for research registries and research training and education.

CONCLUSION

To advance spine care worldwide, spine societies should establish guidelines, conduct studies on pain management, and support predictive analytic modeling. Tailoring local/regional programs according to regional needs is advised. These results can assist spine societies in developing long-term research strategies and provide justified rationale to governments and funding agencies.

International Variability in Spinal Metastasis Treatment: A Survey of the AO Spine Community

STUDY DESIGN

International survey.

OBJECTIVES

To assess variability in the treatment practices for spinal metastases as a function of practice setting, surgical specialty, and fellowship training among an international group of spine surgeons.

METHODS

An anonymous internet-based survey was disseminated to the AO Spine membership. The questionnaire contained items on practice settings, fellowship training, indications used for spinal metastasis surgery, surgical strategies, multidisciplinary team use, and postoperative follow-up priorities and practice.

RESULTS

341 gave complete responses to the survey with 76.3% identifying spinal oncology as a practice focus and 95.6% treating spinal metastases. 80% use the Spinal Instability Neoplastic Score (SINS) to guide instrumentation decision-making and 60.7% recruit multidisciplinary teams for some or all cases. Priorities for postoperative follow-up are adjuvant radiotherapy (80.9%) and systemic therapy (74.8%). Most schedule first follow-up within 6 weeks of surgery (62.2%). Significant response heterogeneity was seen when stratifying by practice in an academic or university-affiliated center, practice in a cancer center, completion of a spine oncology fellowship, and self-identification as a tumor specialist. Respondents belonging to any of these categories were more likely to utilize SINS (P < .01-.02), recruit assistance from plastic surgeons (all P < .01), and incorporate radiation oncologists in postoperative care (P < .01-.03).

CONCLUSIONS

The largest variability in practice strategies is based upon practice setting, spine tumor specialization, and completion of a spine oncology fellowship. These respondents were more likely to use evidenced-based practices. However, the response variability indicates the need for consensus building, particularly for postoperative spine metastasis care pathways and multidisciplinary team use.

Chemoprophylactic Anticoagulation Following Lumbar Surgery Significantly Reduces Thromboembolic Events After Instrumented Fusions, Not Decompressions

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To quantify any reduction in venous thromboembolic events (VTEs) caused by chemoprophylaxis among lumbar surgery patients.

SUMMARY OF BACKGROUND DATA

Chemoprophylactic anticoagulation (chemoprophylaxis) is used to prevent VTE after lumbar surgery. However, the treatment effect of chemoprophylaxis has not been reported among spine surgery patients, as conventional statistical methods preclude such inferences.

MATERIALS AND METHODS

A total of 1243 consecutive lumbar fusions and 1433 noninstrumented lumbar decompressions performed at our institution over a six-year period were identified, and clinical and demographic data were collected, including on VTE events within 30 days postoperatively. Instrumented lumbar fusions and noninstrumented lumbar surgeries were analyzed separately. Patients who were given chemoprophylaxis (treatment) and controls were matched according to known VTE risk factors, including age, body mass index, sex, diabetes, chronic kidney disease, history of VTE, estimated blood loss, length of surgery, transfusion, whether surgery was staged, and whether surgery used an anterior approach. K-nearest neighbor propensity score matching was performed, and the treatment effect of chemoprophylaxis was calculated.

RESULTS

Unadjusted, there was no difference in the rate of VTE between treatment and controls in either population. Baseline clinical and demographic characteristics differed significantly between treatment and control groups. In all, 575 lumbar fusion patients and 435 noninstrumented lumbar decompression patients were successfully propensity score matched, yielding balanced models (Rubin B <25, 0.5<Rubin R <2.0) and >60% reduction in known bias for both populations. The treatment effect of chemoprophylaxis after lumbar fusion in our patient population was a reduction in VTE incidence from 9.4% to 4.2% ( P <0.05), and propensity score adjusted regression confirmed a reduced odds of VTE with chemoprophylaxis (odds ratio=0.37, P =0.035). The treatment effect was not significant for noninstrumented lumbar decompression patients.

CONCLUSION

Among patients undergoing instrumented lumbar fusions, chemoprophylactic anticoagulation causes a significant reduction in VTE, but causes no significant reduction among patients undergoing noninstrumented lumbar decompression.

Comparison between rivaroxaban versus enoxaparin for venous thromboembolism prophylaxis following spine surgeries, a randomized clinical trial

BACKGROUND

Enoxaparin is currently used for VTE prophylaxis. Rivaroxaban is more cost-effective and is as potent as enoxaparin in VTE prophylaxis.

METHODS

The study was held at Al-Zahra and Kashani university hospitals in Isfahan, Iran, from January 2019 to October 2020. Two hundred ninety-six patients requiring instrumented spine surgery were enrolled; 23 were excluded (lack of consent/interfering medical situations). They were randomized into the groups of rivaroxaban (case, n = 137) and enoxaparin receiving (control, n = 136). Medical data were recorded and 244 patients (case = 123, control = 121) were analyzed value < 0.05 was meaningful.

RESULTS

150 patients were males, and 94 were females. The mean age was 52.09 ± 12.6 years. Postoperative drain volume was higher in rivaroxaban received patients than in enoxaparin (p = 0.02). Post-operation epidural hematoma was detected in 3 patients in the case and 1 in the control group, which was not meaningful(p = 0.622). All of them were evacuated surgically. POH was associated with cervical canal stenosis surgery, existing comorbidities, and new medical events. New medical events were associated with postoperative wound dehiscence (p = 0.001). Short and long-term postoperative outcomes were similar in both groups. The mean follow-up duration was 25.8 ± 7.5 months.

CONCLUSION

Rivaroxaban is as effective as enoxaparin in venous thromboembolic event prophylaxis. Regarding postoperative epidural hematoma, statistical analysis showed equal safety of both drugs. Still, the authors would like to recommend more discretion in rivaroxaban administration in cervical spine laminectomy until future studies are conducted.

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.

Current Guidelines and Practice Recommendations to Prevent Hospital-Acquired Conditions After Major Orthopaedic Surgeries

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In 2016, a total of 48,771 hospital-acquired conditions (HACs) were reported in U.S. hospitals. These incidents resulted in an excess cost of >$2 billion, which translates to roughly $40,000 per patient with an HAC.

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Current guidelines for the prevention of venous thromboembolism and surgical site infection consist primarily of antithrombotic prophylaxis and antiseptic technique, respectively.

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The prevention of catheter-associated urinary tract infection (CA-UTI) and in-hospital falls and trauma is done best via education. In the case of CA-UTI, this consists of training staff about the indications for catheters and their timely removal when they are no longer necessary, and in the case of in-hospital falls and trauma, advising the patient and family about the patient's fall risk and communicating the fall risk to the health-care team.

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Blood incompatibility is best prevented by implementation of a pretransfusion testing protocol. Pressure ulcers can be prevented via patient positioning, especially during surgery, and via postoperative skin checks.

Narrative Review of Antiplatelet and Anticoagulant Medications for Venous Thromboembolism Prevention in Spine Surgery

STUDY DESIGN

This was a narrative review.

OBJECTIVE

The objective of this study was to identify commonly utilized venous thromboembolism (VTE) prophylactic measures, spine surgeon perspective, and provide pharmacologic recommendations from the literature.

SUMMARY OF BACKGROUND DATA

Considered a preventable cause of morbidity and mortality, VTE remains an important iatrogenic diagnosis of concern. Reported rates of VTE following spine surgery vary widely (0.3%-31.0%).

MATERIALS AND METHODS

A MEDLINE query identified literature reporting on VTE prevention and outcomes in the setting of spine surgery. Findings extracted from the included articles were summarized in a narrative review format to identify salient aspects of the current literature.

RESULTS

Sixty articles were summarized. Many anticoagulation medications that are described in the literature target factors involved in the coagulation cascade common pathway including aspirin and other antiplatelet medications, heparins, and warfarin. Newer direct inhibitors of thrombin and factor Xa are now being utilized for VTE prevention, although with limited use specifically in spine surgery.

CONCLUSIONS

Perioperative management of antiplatelet and anticoagulation medications in spine surgery requires evidence-based protocols that can account for patient comorbidities and surgery-specific features. Future studies should prospectively focus on establishing stronger recommendations based on pathology, surgical indications, patient comorbidities, region of the spine, and broad surgical intervention to enable effective prophylaxis for VTE.

LEVEL OF EVIDENCE

Level II.