Low-molecular-weight heparin prophylaxis 24 to 36 hours after degenerative spine surgery: risk of hemorrhage and venous thromboembolism

Global Research Status and Trends in Venous Thromboembolism After Spinal Surgery: A Bibliometric Analysis

BACKGROUND

There has been a growing interest in venous thromboembolism following spinal surgery over the past few years. However, there currently needs to be a bibliometric report on this field. This study aims to construct the knowledge structure of venous thromboembolism after spinal surgery and explores the current status of research productivity, research directions, hotspots, and trends.

METHODS

All articles related to venous thromboembolism after spinal surgery from the Web of Science Core Collection database for 1990 to 2023 were retrieved. For bibliometric analysis, information extraction involves country/region, institutions, journals, authors, references, and keyword-related data.

RESULTS

In this study, a total of 814 articles were identified. Studies related to venous thromboembolism after spinal surgery are showing an increasing trend, with the United States contributing the most. JOHNS HOPKINS UNIVERSITY is a high-productivity institution. The journal "SPINE" is highly productive. Research directions cover venous thromboembolism and bleeding, risk factors and prevention, complications, and perioperative blood protection strategies. Current research hotspots are risk factors, surgical location and approach, and perioperative blood protection strategies. Future research trends include establishing a predictive system for venous thromboembolism after spinal surgery to guide personalized prevention and treatment.

CONCLUSIONS

This study constructed the knowledge structure of venous thromboembolism after spinal surgery, revealing current research hotspots and future trends. Future research trends include personalized prevention and treatment strategies for venous thromboembolism after spinal surgery, especially safe and effective chemical prophylaxis. It is hoped that this study can lay the foundation for subsequent research.

Safety and efficacy of apixaban vs. enoxaparin in thromboprophylaxis after spinal stenosis and degenerative spine surgery

INTRODUCTION

Degenerative spine surgeries often require postoperative immobilization or reduced mobility, predisposing patients to the formation of thrombosis and higher risk of thromboembolic complications. Despite the significance of this issue, there remains a lack of consensus on the optimal anticoagulant agent for postoperative thromboprophylaxis in spinal stenosis and degenerative spine surgeries. Low molecular weight heparins and direct Xa inhibitors represent two anticoagulant groups with high chemoprophylactic potential.

METHODS

This study included a prospective cohort of patients undergoing posterior decompressive surgery with or without instrumentation for degenerative spine disease and/or spinal stenosis. Patients receiving postoperative prophylactic Enoxaparin and Apixaban were selected to evaluate the rate of complications, as assessed by Clavien-Dindo classification, thromboembolic events, and 30-day mortality, readmission, and reoperation rate between the two anticoagulants.

RESULTS

130 patients were included in the analysis. 65 patients received Apixaban and Enoxaparin in each group. Mean age of the participants was 57.6±11.0. 83.1% underwent laminectomy and posterior spinal fusion, while 22 patients underwent decompressive surgery only. The incidence of venous thromboembolism (P-value=0.403), deep vein thrombosis (p-value=0.999), hematoma formation (p-value=0.403), surgical site infection (p-value=0.901), readmission (p-value=0.545), reoperation (p=0.510), mortality (p=0.648), and complications rate (p-value=0.232) were not statistically different between Enoxaparin and Apixaban.

DISCUSSION

Both Apixaban and Enoxaparin may be viable options for postoperative thromboprophylaxis in spine surgeries with comparable efficacy and safety profile. Future research endeavors should investigate the efficacy of these agents in comparison to placebo in a randomized setting.

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.

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.

Severe Symptomatic Epidural Hematoma Following Percutaneous Endoscopic Unilateral Laminectomy for Bilateral Decompression (Endo-ULBD)-Series Report and Management Strategies

OBJECTIVES

Severe symptomatic epidural hematoma (SSEH) is one of the most severe complications following percutaneous endoscopic unilateral laminectomy for bilateral decompression (Endo-ULBD). Considering that this technique has been performed for a short time, no detailed reports have been recently published. Thus, it is critical to gain a better understanding of SSEH occurring in its postoperative period with regard to its incidence, possible causes, outcome, etc., in order to identify relevant management strategies.

METHODS

Patients with spinal stenosis who had undergone Endo-ULBD in our department from May 2019 to May 2022 were retrospectively analyzed. Of which, patients with postoperative epidural hematoma were followed-up. The preoperative and postoperative physical conditions of each patient were recorded, and the information related to hematoma removal surgery was recorded in detail. Clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry disability index (ODI), and the results were classified into "excellent," "good," "fair," or "poor" based on the modified MacNab criteria. The incidence of hematoma with different factors was calculated, and a bar graph was used to compare the difference of the indexes related to hematoma removal between cases, and a line graph was used to reflect the trend of the outcome of each patient within 6 months to evaluate the effect of the treatment.

RESULTS

A total of 461 patients with spinal stenosis who underwent Endo-ULBD were enrolled in the study. SSEH occurred in four cases, with an incidence rate of 0.87% (4/461). All these four patients underwent decompression of multiple segments, and three of them had a history of hypertension comorbid with diabetes. Notably, one patient had a past history of hypertension and coronary artery disease and was on postoperative low molecular heparin due to lower extremity venous thrombosis. According to the conditions of the four patients, three types of treatment were used. And with timely treatment, all patients recovered well.

CONCLUSION

Despite being a minimally invasive technique, postoperative epidural hematoma remains a severe complication of Endo-ULBD. Therefore, during percutaneous endoscopic surgery, it is essential to enhance the comprehensive perioperative management of patients with Endo-ULBD. Signs related to postoperative hematoma must be recognized and promptly managed. If necessary, satisfactory results can be achieved by using percutaneous endoscopy along the original surgical channel to remove the hematoma.

Successful treatment of thoracic myelopathy caused by spontaneous spinal epidural hematoma (SSEH) combined with calcification of the ligamentum flavum (CLF) by posterior percutaneous endoscopic surgery (PPES): A case report

Study Design

A retrospective case report.

Objective

To report a case who developed deteriorated paraplegia by spontaneous spinal epidural hematoma (SSEH) based on calcification of the ligamentum flavum (CLF) at the T10-11 level, achieved full neurological recovery following posterior percutaneous endoscopic surgery (PPES).

Summary of Background Data

CLF rarely occurs at the thoracic spine, and the symptom usually progress slowly. SSEH is another rare spinal lesion that might progress rapidly and cause emergent severe spinal cord compression syndrome. Coexistence of SSEH and CLF at the same thoracic level was rarely reported in English literature.

Methods

A 65-year-old man presented to our hospital with the complaint of sensorimotor loss on the lower limbs and dysfunction of bladder for 1 day after a progressive weakness and numbness of the lower limbs for 3 months. MR examination found a dorsal protruding mass at the T10-11 level, while computed tomography (CT) found the protruding mass contained scattered calcified deposits. The patient was diagnosed with thoracic CLF. Decompression via PPES was carried out to realize bilateral decompression through a unilateral approach.

Results

During the operation, the protruding mass was found to be composed of SSEH and CLF together. After the operation, the patient's neurological function recovered quickly. One week later, the patient could walk by himself. After 3 months, complete neurological function had recovered.

Conclusion

SSEH could develop based on CLF at thoracic level and cause serious neurological dysfunction. PPES might be an advisable method to remove CLF and evacuate SSEH with good clinical results.

Delayed postoperative spinal epidural hematoma after anterior cervical discectomy and fusion: A case report

Background

Postoperative spinal epidural hematoma (POSEH) causes rapid neurological deficits within 24 h following the operation and can be fatal. However, some POSEH symptoms manifest three days after the operation, also known as delayed POSEH (DPOSEH). Little attention has been provided upon DPOSEH owing to its rare incidence, resulting in serious consequences upon occurrence. To date, no cases of delayed POSEH after anterior cervical surgery have been reported.

Case presentation

We describe a case of DPOSEH that presented with delayed neurological deficits on the fifth day after anterior cervical discectomy and fusion (ACDF) surgery. Methylprednisolone was administered but showed no efficacy. MR revealed low T1 and strip long T2 signals located behind discs. After emergency surgical decompression, the patient's muscle strength returned to the preoperative state. However, his muscle strength decreased again on the seventh postoperative day, and the patient's family refused further surgery. Nine months after ACDF, the patient died of septic shock and respiratory failure.

Conclusions

DPOSEH can occur after three days or more following anterior cervical surgery; hence, monitoring of neurological function is suggested to be extended. Complete evaluation of risk factors, timely recognition, and differentiation of neurological symptoms are required for spine surgery. In the case of DPOSEH, methylprednisolone can be administered reasonably during the transition period. However, if there is no resolution of symptoms, emergency surgery should be performed as soon as possible.

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.

Venous thromboembolism chemical prophylaxis after endoscopic trans-sphenoidal pituitary surgery

PURPOSE

There 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.

METHODS

Single-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.

RESULTS

651 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).

CONCLUSIONS

Chemoprophylaxis 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.

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.

Exosomal myeloperoxidase as a biomarker of deep venous thrombosis

BACKGROUND

Deep vein thrombosis (DVT) often occurs following major orthopedic surgery. In this study, we investigated specific exosomal proteins as potential diagnostic biomarkers of DVT.

METHODS

Proteomic analysis of exosomes from four DVT patients and healthy controls (n=4) was performed by mass spectrometry. The model animals were evaluated at 1 inferior vena cava ligation [(IVCL)-1D], 3 (IVCL-3D), and 7 (IVCL-7D) days after IVCL. Endothelial cells in the thrombus segment were examined using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays and hematoxylin and eosin (HE) staining. Myeloperoxidase (MPO) expression in the damaged vessel was detected by immunofluorescence staining. Exosomes were co-cultured with human umbilical vein endothelial cells (HUVECs) and cell proliferation was estimated using Cell Counting Kit-8 (CCK-8) assays.

RESULTS

A total of 78 differentially expressed proteins (DEPs; 38 downregulated and 40 upregulated) were identified in the DVT group. In the rat DVT model, endothelial cells were damaged continuously after thrombosis, with the most serious injury in the IVCL-3D group, after which signs of endothelial repair were apparent. The IVCL-1D group showed the highest levels of vascular endothelial cell apoptosis and MPO increased sharply in the IVCL-1D and IVCL-3D groups, but had almost disappeared in the IVCL-7D group. In co-culture, plasma exosomes isolated from DVT model rats were efficiently absorbed by HUVECs, with markedly lower HUVECs growth and higher levels of apoptosis in the IVCL-1D and IVCL-3D groups compared with the control group.

CONCLUSIONS

Our findings suggest that exosomes may be involved in endothelial cell injury during DVT. The exosomal protein MPO is a potential biomarker of early stage DVT.

THE USE OF CHEMOPROPHYLAXIS OR NOT FOR DVT IN SPINE SURGERY: A SYSTEMATIC REVIEW

ABSTRACT Objective: To compare pharmacological and non-pharmacological prophylaxis in elective spine surgery to determine the risks of DVT, PTE, and epidural hematoma (EH) in both groups, as well as their respective treatment effectiveness. Methods: Systematic review and meta-analysis based on systematically searched articles, using combinations of MeSH terms related to chemoprophylaxis and non-chemoprophylaxis for prevention of deep vein thrombosis and pulmonary embolism in elective spine surgery. Adult patients were eligible for inclusion in the study, except for those with trauma, spinal cord injury, neoplasms, or those using vena cava filters. Results: Five studies were selected for this systematic review and meta-analysis: 3 retrospective studies, 1 prospective study, and 1 case series. Data analysis showed that 4.64% of patients treated with chemoprophylaxis had an unfavorable outcome regarding DVT, while this outcome occurred in 1.14% of patients not treated with chemoprophylaxis (p=0.001). Among patients using chemoprophylaxis, only 0.1% developed epidural hematoma and 0.38% developed PTE. Among those on non-pharmaceutical prophylaxis, 0.04% had EH (p=0.11) and 0.42% had PTE (p=0.45). Conclusions: No benefits were found for chemoprophylaxis as compared to non-chemoprophylaxis in preventing DVT in elective spine surgery, nor was there an increased risk of epidural hematoma or fatal thromboembolic events. Level of evidence III; Therapeutic studies; Investigation of treatment results.

Analysis of Related Influencing Factors of Deep Vein Thrombosis after Lumbar Internal Fixation and Treatment Strategy

Lumbar internal fixation is a traditional surgical method for the treatment of degenerative diseases of the lumbar spine. However, due to its large surgical trauma, it easily causes complications such as deep venous thrombosis (DVT) after the operation. DVT refers to the abnormal coagulation of blood in deep veins, blocking the lumen, causing venous blood return disorder, causing venous blood return disorder to cause swelling and pain, which affects the recovery of the patient's lumbar spine function. In severe cases, even complicated pulmonary embolism endangers the life and health of the patient. Therefore, it is extremely important to explore the related influencing factors and effective treatment of DVT. The purpose of this study was to investigate the influencing factors and effective treatment of DVT after lumbar internal fixation. Univariate analysis and multivariate a logistic regression model were used to analyze the related factors affecting DVT after lumbar internal fixation. Conventional treatments such as anticoagulation, promotion of venous blood return, and improvement of limb circulation were given to patients with DVT, and functional exercise was guided to compare the hypercoagulability and hyperviscosity of blood in patients with DVT before and after treatment. The results showed that the incidence of DVT after lumbar internal fixation was related to age, BMI, and bed time. Getting out of bed for functional exercise in time after surgery can effectively prevent the formation of DVT. Preoperative grading examination, intraoperative intervention, postoperative physical exercise, and other preventive guidance can be carried out according to different individuals during the perioperative period to prevent the formation of postoperative DVT.

Venous Thromboembolism Prophylaxis in Elective Spine Surgery

STUDY DESIGN

Review.

OBJECTIVE

Venothromboembolic (VTE) complications, composed of deep vein thrombosis and pulmonary embolism are commonly observed in the perioperative setting. There are approximately 500 000 postoperative VTE cases annually in the United States and orthopedic procedures contribute significantly to this incidence. Data on the use of VTE prophylaxis in elective spinal surgery is sparse. This review aims to provide an updated consensus within the literature defining the risk factors, diagnosis, and the safety profile of routine use of pharmacological prophylaxis for VTE in elective spine surgery patients.

METHODS

A comprehensive review of the literature and compilation of findings relating to current identified risk factors for VTE, diagnostic methods, and prophylactic intervention and safety in elective spine surgery.

RESULTS

VTE prophylaxis use is still widely contested in elective spine surgery patients. The outlined benefits of mechanical prophylaxis compared with chemical prophylaxis varies among practitioners.

CONCLUSION

The benefits of any form of VTE prophylaxis continues to remain a controversial topic in the elective spine surgery setting. A specific set of guidelines for implementing prophylaxis is yet to be determined. As more risk factors for thromboembolic events are identified, the complexity surrounding intervention selection increases. The benefits of prophylaxis must also continue to be balanced against the increased risk of bleeding events and neurologic injury.

Pharmacoprophylaxis for Venous Thromboembolism in Spinal Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

Venous thromboembolism (VTE) is a significant contributor to postoperative morbidity and mortality. Prophylactic regimens for VTE involve mechanical prophylaxis and pharmacoprophylaxis. This systematic review and meta-analysis aimed to determine the efficacy and safety of pharmacoprophylaxis in comparison with any nonpharmacoprophylaxis regimen for the prevention of postoperative VTE in patients undergoing spinal surgery.

METHODS

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and ICRCTN were searched for comparative studies including both pharmacoprophylaxis and nonpharmacoprophylaxis post spinal surgery. The primary outcome was the incidence of VTE within the postoperative hospitalized period. Secondary outcomes included the incidence of spinal epidural hematoma, significant bleeding events, and other adverse events associated with VTE. The data was pooled using random-effects models of meta-analysis and relative risk (RR) was calculated.

RESULTS

Four retrospective and 3 randomized controlled trials representing a total of 8373 patients were included. Overall, there was a significant decrease in postoperative deep venous thrombosis with pharmacoprophylaxis versus nonpharmacoprophylaxis (RR 0.42, 95% confidence interval 0.21-0.86, P = 0.02, I2 = 0%); however, there were no significant differences between the groups in the incidences of VTE (RR 0.31, 95% confidence interval 0.12-0.81, P = 0.02, I2 = 0%). The incidences of spinal epidural hematoma and significant bleeding events were rare and comparable in both groups.

CONCLUSIONS

This systematic review and meta-analysis found a potential benefit with pharmacoprophylaxis post spinal surgery in the prevention of deep venous thrombosis. However, there is a need for future randomized controlled trials to investigate the efficacy and safety of pharmacoprophylaxis in spinal surgery across various spinal procedures.

Impact of acetylsalicylic acid (ASA) on postoperative hemorrhage in spinal lumbar surgery: Should preoperative ASA be discontinued for elective surgery?

OBJECTIVE

The application of acetylsalicylic acid (ASA) represents high evidence in the aging society due to primary and secondary prevention in cardiovascular disease and stroke. However, this presents a challenge for neurosurgeons in terms of preoperative and postoperative management of care. This study aimed to analyze the risk of bleeding by applying ASA before lumbar spinal surgery.

METHODS

Retrospective analysis of medical records of 3051 patients was performed from 2008 to 2018 who underwent lumbar surgery at our institution. The risk of postoperative hemorrhage was compared in patients treated with ASA versus patients without ASA treatment. Additionally, the relationship between discontinuation of ASA preoperatively (≥7 days) or no previous history of ASA versus continuation with ASA (<7 days) on postoperative hemorrhage was analyzed.

RESULTS

Postoperative hemorrhagic were observed in 2.1% (n = 63) of all lumbar operations. In 421 patients, the effect of ASA (<7 days) was still persistent at the time of surgery (ASA impact group). Of these, 12 (2.85%) patients had a hemorrhage. No significant differences were found in comparison to the No ASA impact group (p = 0.272). Sex (p = 0.003), hypertension (p = 0.015), recurrent surgery (p = 0.001) and use of hemostatic agents (p = 0.023) had a significant impact on postoperative hemorrhage.

CONCLUSION

The continuation of ASA medication is not associated with increased risk of postoperative hemorrhage after spinal surgery. However, sex, hypertension, recurrent surgery and the use of hemostatic agents under continued ASA treatment were found to be associated with an increased risk of hemorrhage.

Which Criterion for Wound Drain Removal is Better Following Posterior 1-Level or 2-Level Lumbar Fusion With Instrumentation: Time Driven or Output Driven?

STUDY DESIGN

Case-control study.

OBJECTIVES

To compare the outcomes of 2 different criteria (time driven and output driven) for wound drain removal and identify which one is better.

METHODS

743 patients who underwent posterior lumbar fusion with instrumentation involving 1 or 2 motion segments were enrolled in this study. Based on the different criteria for drain removal, the patients were divided into 2 groups. The drains were discontinued by time driven (postoperative day 2) in group I and output driven (<50 ml per day) in group II. Demographic characteristics, perioperative parameters and clinical outcomes were compared between the 2 groups.

RESULTS

The demographic characteristics in both groups were comparable. The postoperative drain output, total blood loss, postoperative timing of ambulation, and postoperative duration of hospital stay in group I were lower than those in group II (P < 0.001). There was a higher proportion of patients requiring postoperative blood transfusion in group II, but not to a level of statistical significance (P = 0.054). There was no statistical significant difference in the incidence of surgical site infection (SSI) or symptomatic spinal epidural hematoma (SEH) between the 2 groups (P > 0.05).

CONCLUSIONS

This study reveals that there are more benefits of wound drain removal by time driven than that by output driven for patients undergoing posterior 1-level or 2-level lumbar fusion with instrumentation, including less postoperative drain output, less total blood loss, earlier postoperative timing of ambulation and less postoperative duration of hospital stay without increasing the incidence of postoperative SSI or symptomatic SEH.

Venous Thromboembolism in Trauma: The Role of Anticoagulation and Inferior Vena Cava Filters

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality among patients with severe trauma. Historically, prophylactic inferior vena cava filters (IVCFs) were used in high-risk trauma patients with suspected risk factors for VTE, including prolonged immobilization, and concurrent contraindication to anticoagulation. Mounting data regarding the efficacy of IVCF in this cohort, as well as concerns regarding morbidity of an in situ IVCF, have challenged this practice paradigm. In this review, we discuss the comanagement of VTE and trauma, including anticoagulation and the use of IVCF.

Use of Fondaparinux Following Elective Lumbar Spine Surgery Is Associated With a Reduction in Symptomatic Venous Thromboembolism

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess the impact of fondaparinux on venous thromboembolism (VTE) following elective lumbar spine surgery in high-risk patients.

METHODS

Matched patient cohorts who did or did not receive inpatient fondaparinux starting postoperative day 2 following elective lumbar spine surgery were compared. All patients received 1 month of acetyl salicylic acid 325 mg following discharge. The primary outcome was a symptomatic DVT (deep vein thrombosis) or PE (pulmonary embolus) within 30 days of surgery. Secondary outcomes included prolonged wound drainage, epidural hematoma, and transfusion.

RESULTS

A significantly higher number of DVTs were diagnosed in the group that did not receive inpatient VTE prophylaxis (3/102, 2.9%) compared with the fondaparinux group (0/275, 0%, P = .02). Increased wound drainage was seen in 18.5% of patients administered fondaparinux, compared with 25.5% of untreated patients (P = .15). Deep infections were equivalent (2.2% with fondaparinux vs 4.9% control, P = .18). No epidural hematomas were noted, and the number of transfusions after postoperative day 2 and 90-day return to operating room rates were equivalent.

CONCLUSIONS

Patients receiving fondaparinux had lower rates of symptomatic DVT and PE and a favorable complication profile when compared with matched controls. The retrospective nature of this work limits the safety and efficacy claims that can be made about the use of fondaparinux to prevent VTE in elective lumbar spine surgery patients. Importantly, this work highlights the potential safety of this regimen, permitting future high-quality trials.

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

STUDY DESIGN

Cross-sectional, international survey.

OBJECTIVES

This study addressed the global perspectives concerning perioperative use of pharmacologic thromboprophylaxis during spine surgery along with its risks and benefits.

METHODS

A questionnaire was designed and implemented by expert members in the AO Spine community. The survey was distributed to AO Spine's spine surgeon members (N = 3805). Data included surgeon demographic information, type and region of practice, anticoagulation principles, different patient scenarios, and comorbidities.

RESULTS

A total of 316 (8.3% response rate) spine surgeons completed the survey, representing 64 different countries. Completed surveys were primarily from Europe (31.7%), South/Latin America (19.9%), and Asia (18.4%). Surgeons tended to be 35 to 44 years old (42.1%), fellowship-trained (74.7%), and orthopedic surgeons (65.5%) from academic institutions (39.6%). Most surgeons (70.3%) used routine anticoagulation risk stratification, irrespective of geographic location. However, significant differences were seen between continents with anticoagulation initiation and cessation methodology. Specifically, the length of a procedure (P = .036) and patient body mass index (P = .008) were perceived differently when deciding to begin anticoagulation, while the importance of medical clearance (P < .001) and reference to literature (P = .035) differed during cessation. For specific techniques, most providers noted use of mobilization, low-molecular-weight heparin, and mechanical prophylaxis beginning on postoperative 0 to 1 days. Conversely, bridging regimens were bimodal in distribution, with providers electing anticoagulant initiation on postoperative 0 to 1 days or days 5-6.

CONCLUSION

This survey highlights the heterogeneity of spine care and accentuates geographical variations. Furthermore, it identifies the difficulty in providing consistent perioperative anticoagulation recommendations to patients, as there remains no widely accepted, definitive literature of evidence or guidelines.

Thromboprophylaxis in elective spinal surgery: A protocol for systematic review

BACKGROUND

Venous thromboembolism (VTE) is a serious, sometimes life-threatening complication that can occur following spine surgery. The incidence of VTE, and the optimal type and timing of thromboprophylaxis for this complication in elective spine surgery is a matter of debate.

OBJECTIVE

To perform a systematic review with the aim of clarifying the efficacy and adverse effects of mechanical and chemical prophylaxis for preventing thromboembolic complications in elective spine surgery for conditions other than trauma and malignant disease.

METHODS/DESIGN

A search strategy of related articles up to March 2018 was designed and executed in Medline and Embase.

PATIENTS

adolescents (>10 years) and adults undergoing elective surgery for spinal deformity or degenerative disease (from C1 to S1).

INTERVENTION

Perioperative mechanical and chemical thromboprophylaxis. Studies could be randomized controlled trials or observational studies that reported data on any relevant clinical outcomes.

RESULTS

In total, 2451 uniquecitations were identified and 35 studies were ultimately included in the systematic review. The overall mean incidence of complications was 3.7% for deep venous thrombosis, 0.0% for pulmonary embolism, and 3.7% for bleeding in chemoprophylaxis group; 2.9% for deep venous thrombosis, 0.4% for pulmonary embolism and 0.0% for bleeding in mechanoprophylaxis; and 0.7% for deep venous thrombosis, 0.1% for pulmonary embolism and 0.2% for bleeding in mixed prophylaxis group with no specific data on these rates for the type of patient and type and location of surgery. None of the articles retrieved provided information on the adolescent population.

DISCUSSION AND CONCLUSIONS

The poor design and high variability among the studies regarding characteristics of study population, details of interventions, and definitions of outcomes, determines a low quality of the available evidence and limits the interpretation of the results. We were unable to identify a clear advantage of one type of thromboprophylaxis over the other, although there was an increased risk of bleeding with chemoprophylaxis, which could favor the use of mechanoprophylaxis in this scenario.

Perioperative prevalence of deep vein thrombosis in patients with percutaneous kyphoplasty: A retrospective study with routine ultrasonography

In recent years, deep venous thrombosis (DVT) after spine surgery has received extensive attention, but perioperative prevalence of DVT in patients undergoing percutaneous kyphoplasty (PKP) is lacking.To assess the perioperative prevalence of deep vein thrombosis (DVT) in patients undergoing PKP with routinely applied ultrasonography.We reviewed 1113 consecutive patients undergoing PKP from January 2014 to August 2017. The surgical procedure was bilateral PKP. All patients were routinely examined with ultrasonography when admitted to the hospital and on the first post-operative day. Clinical signs of DVT were checked and recorded before examination.Forty (3.6%) out of 1113 patients were diagnosed with DVT by ultrasonography. Of the 40 detected cases of DVT, only six (0.54%) patients presented with clinical signs of DVT, demonstrating that there were 34 (3.05%) asymptomatic cases. No patient presenting with clinically suspected pulmonary embolism (PE) was observed. Gender, body mass index (BMI), operative time, hypertension, diabetes, heart disease, and lower limb fracture were not significant risk factors for DVT (P > .05). In contrast, patient age, oncologic conditions, DVT history, and paraplegia appeared to be significant risk factors for DVT (P < .01). There was no significant difference in the incidence of DVT found between the three PKP surgical levels (P > .05).The total incidence of perioperative DVT diagnosed with ultrasonography in patients undergoing PKP was 3.6%, of which only 0.54% was symptomatic cases. It is necessary to assess DVT using ultrasonography during the perioperative procedure of PKP, especially for high-risk patients.Level of evidence: Level IV.

Venous Thromboprophylaxis in Spine Surgery

STUDY DESIGN

Review article.

OBJECTIVE

A review of the literature on postoperative initiation of thrombophylactic agents following spine surgery.

METHODS

A review of the literature and synthesis of the data to provide an update on venous thromboprophylaxis following spine surgery.

RESULTS

Postoperative regimens of venous thromboprophylaxis measures following spine surgery remain a controversial issue. Recommendations regarding mechanical versus chemical prophylaxis vary greatly among institutions.

CONCLUSION

Postoperative spine surgery initiation of thromboprophylaxis remains controversial regarding optimal timing and agent selection. The benefits of deep vein thrombosis/pulmonary embolism prophylaxis must be weighed against the possible postoperative complications associated with spine surgery.

Time-to-event analyses of lower-limb venous thromboembolism in aged patients undergoing lumbar spine surgery: a retrospective study of 1620 patients

After spine surgery, venous thromboembolism (VTE) is not uncommon in aged patients. This study investigates time-to-event risk factors of postoperative VTE based on medical records of aged patients (age≥60 yr) between January 2013 and December 2018. All participants had undergone lower extremity ultrasonography pre- and postoperatively at the first, second, fourth, eighth, and twelfth weeks. Mann-Whitney U tests and chi-square tests were used for univariate analyses, and Cox regression was utilized for multivariate analyses. A total of 1620 cases were recruited, VTE group (N=382, 23.6%) and non-VTE group (N=1238, 76.4%), aged 67 (IQR 11) years and 65 (IQR 6) years, respectively. The univariate analyses indicated significant differences between the VTE and non-VTE groups regarding advanced age, VTE history, hypertension, fusion, hospital stay, FIB, HDL, D-dimer, and TC (all P<0.05). The Cox regression showed that advanced age (OR=1.108; 95% CI, 1.091–1.126), VTE history (OR=4.962; 95% CI, 3.849–6.397), and hypertension (OR=1.344; 95% CI, 1.084–1.667) were the risk factors for postoperative VTE (P<0.05). The time-to-event analyses indicated that the hazard of VTE formation was highest in the first postoperative week. In conclusion, advanced age, VTE history, and hypertension are main risks for VTE formation, particularly in the first postoperative week.

Spontaneous Cervical Epidural Hematoma with Stroke Manifestations

Spontaneous cervical epidural hematoma (SCEH), which is a rare disease, is manifested as by a sudden quadriplegia or paraplegia and other neurological deficits. SCEH can compress the spinal cord resulting in its clinical manifestations. The reported etiological risk factors are anticoagulants, coagulopathies, vascular malformations, infections, and herniated discs. Here, we report a 77-year-old woman with a presenting chief complaint of left hemiparesis and a history of hypertension. The medical drugs in use were aspirin and antihypertensives. The initiating presentations were hemiparesis, in favor of ischemic stroke, so the patient admitted to neurology ward and received anticoagulant therapy with the initial diagnosis of stroke. Although clinical manifestations and examinations are important in these patients due to mimicking stroke picture, imaging evaluation is paramount for a definite diagnosis, which in our case showed a SCEH, who was suspected to have an ischemic stroke during the initial assessment because its initial demonstration mimicked ischemic stroke. This patient underwent laminectomy after 3 days and showed a clinical recovery the day after. Her muscle strength improved gradually, and neurological symptoms were diminished after physiotherapy.

Risk Factors for Lower Limb Deep Vein Thrombosis in Patients With Single-Level Lumbar Fusion: A Prospective Study of 710 Cases

Lower limb deep vein thrombosis (DVT) is not an uncommon postoperative complication of spinal fusion surgery. However, the related risk factors identified in previous studies remain controversial. This study aimed to investigate risk factors for lower limb DVT in patients with single-level lumbar fusion surgery. Between January 2010 and December 2016, a total of 710 patients undergoing lumbar fusion were recruited for this study, including 172 males and 538 females (aged 18-75 years). Deep vein thrombosis was detected by ultrasonography. Accordingly, patients were divided into the DVT group and the non-DVT group and compared in terms of operative data, underlying diseases, and biochemical data. Additionally, logistic regression analysis was performed to identify risk factors for lower limb DVT. The incidence of lower limb DVT was 11.8% (84 of 710 cases). Five patients were symptomatic, with lower limb pain and swelling. Two patients developed pulmonary embolism and 1 died. Binary logistic regression indicated that advanced age (P = .001, odds ratio [OR] = 2.86, 95% CI: 1.85-5.12), hypertension (P = .006, OR = 4.10, 95% CI: 1.09-2.30), and increased d-dimer (P < .001, OR = 3.49, 95% CI: 2.05-6.36) were risk factors for postoperative DVT. In conclusion, for patients with single-level lumbar fusion, advanced age, increased d-dimer, and hypertension may contribute to DVT development after spinal fusion surgery. Therefore, patients with these risk factors should be protected during the perioperative period.

Venous thromboembolism events following spinal fractures: A single center experience

OBJECTIVE

Venous thromboembolic events (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), are a major cause of readmission, morbidity, and mortality after spine surgery. Patients with spinal fractures are particularly at an increased risk for VTE. The objective of this study is to understand VTE risk factors in this patient population and to examine current institutional practices.

PATIENTS AND METHODS

We retrospectively examined records from 195 consecutive patients with spinal fractures who underwent spinal stabilization surgeries- amongst a cohort of 6869 patients who underwent spinal surgery. We collected data on patient demographics, surgery, hospital course, and 30-day rates of VTE, readmission, reoperation. Multivariable logistic regression was used to identify independent predictors of each outcome.

RESULTS

Among 195 patients undergoing surgery for spinal fractures, 9.2% experienced a VTE, compared to 2.3% among all other spine patients (OR 4.466, p < 0.0001). 48.7% spine fracture patients received chemoprophylactic anticoagulation, compared to 35.7% of all other spine patients (OR 2.657, p < 0.0001). Within 30 days of surgery, estimated blood loss (EBL) was associated with VTE (OR 1.001, p = 0.0415) and DVT (OR 1.001, p = 0.049), and comorbid cardiac disease burden showed a trend toward significance in predicting both VTE (OR 1.890, p = 0.0956) and DVT (OR 4.228, p = 0.0549). Number of levels in surgery predicted PE within 30 days of surgery (OR 1.573, p = 0.0107).

CONCLUSIONS

Compared to all other patients undergoing spine surgery, patients with spinal fractures are more likely to receive chemoprophylactic anticoagulation, but nevertheless have a higher rate of VTE events. EBL and comorbid disease burden predict VTE events in patients with spine fractures.

Venous Thromboembolism Prophylaxis in Spine Surgery

Venous thromboembolism (VTE) is a source of morbidity and mortality in patients undergoing orthopaedic surgery. A substantial body of literature supports the use of VTE prophylactic agents in patients undergoing lower extremity surgery. Treatment options include early mobilization, mechanical prophylaxis via pneumatic compression devices, pharmacologic agents, and venous filters. No consensus has been established regarding utilization or timing of VTE prophylaxis measures after spine surgery. The risk of VTE in patients undergoing spine surgery is not well characterized and varies substantially by the procedure and degree of neurologic compromise. In addition, the risk of clinically notable VTE must be weighed against the risk of postoperative bleeding and epidural hematoma after spine surgery. A standardized approach to VTE prophylaxis in patients undergoing spine surgery must take into account the available studies of risk factors, choice of prophylactic agents, and timing of prophylaxis.

Risk factors and pharmacologic prophylaxis for venous thromboembolism in elective spine surgery

BACKGROUND CONTEXT

Venous thromboembolism (VTE) is a known complication after spine surgery, but prophylaxis guidelines are ambiguous for patients undergoing elective spine surgery.

PURPOSE

The objective of this study was to characterize the incidence and risk factors for VTE and the association of pharmacologic prophylaxis with VTE and bleeding complications after elective spine surgery.

STUDY DESIGN/SETTING

This is a retrospective cohort study of patients undergoing elective spine surgery in the National Surgical Quality Improvement Program (NSQIP) database and a retrospective cohort analysis at an academic medical center.

PATIENT SAMPLE

This study included 109,609 patients in the NSQIP database from 2005 to 2014 and 2,855 patients at the authors' institution from January 2013 to March 2016 who underwent elective spine surgery.

OUTCOME MEASURES

The incidence and risk factors for VTE were assessed in both cohorts based on the NSQIP criteria. The incidence of bleeding complications requiring reoperation was assessed based on operative reports in the institutional cohort.

MATERIALS AND METHODS

Associations of patient and procedure factors with VTE were characterized in the NSQIP population. In the single-institution cohort, in addition to NSQIP variables, a chart review was completed to determine the use of VTE prophylaxis, the history of prior VTE, and the incidence of hematoma requiring reoperation. The association of patient and procedure variables, including pharmacologic prophylaxis and history of prior VTE, with VTE and hematoma requiring reoperation were determined with multivariate regression.

RESULTS

Among 109,609 elective spine surgery patients in NSQIP, independent risk factors for VTE were greater age, male gender, increasing body mass index, dependent functional status, lumbar spine surgery, longer operative time, perioperative blood transfusion, longer length of stay, and other postoperative complications. There were 2,855 patients included in the institutional cohort. Pharmacologic prophylaxis was performed in 56.3% of the institutional patients, of whom 97.1% received unfractionated heparin. When controlling for patient and procedural variables, pharmacologic prophylaxis did not significantly influence the rate of VTE, but was associated with a significant increase in hematoma requiring a return to the operating room (relative risk=7.37, p=.048).

CONCLUSIONS

Pharmacologic prophylaxis, primarily with unfractionated heparin, after elective spine surgery was not associated with a significant reduction in VTE. However, there was a significant increase in postoperative hematoma requiring reoperation among patients undergoing prophylaxis. This raises questions about the routine use of unfractionated heparin for VTE prophylaxis and supports the need for further consideration of risks and benefits of chemoprophylaxis after elective spine surgery.

Venous thromboembolism in adult elective spinal surgery

Aims

To evaluate the incidence of primary venous thromboembolism (VTE), epidural haematoma, surgical site infection (SSI), and 90-day mortality after elective spinal surgery, and the effect of two protocols for prophylaxis.

Patients and Methods

A total of 2181 adults underwent 2366 elective spinal procedures between January 2007 and January 2012. All patients wore anti-embolic stockings, mobilised early and were kept adequately hydrated. In addition, 29% (689) of these were given low molecular weight heparin (LMWH) while in hospital. SSI surveillance was undertaken using the Centers for Disease Control and Prevention criteria.

Results

In patients who only received mechanical prophylaxis, the incidence of VTE was 0.59% and that of SSI 2.1%. In patients who were additionally given LMWH, the incidence of VTE was 0% and that of SSI 0.7%. The unadjusted p-value was 0.04 for VTE and 0.01 for SSI. There were no cases of epidural haematoma or 90-day mortality in either group. When adjusted for case-mix, LMWH remained a significant factor (p = 0.006) for VTE, but not for SSI.

Conclusion

A peri-operative protocol involving mechanical anti-embolism stockings, adequate hydration, and early post-operative mobilisation is effective in significantly reducing the incidence of VTE. The addition of LMWH is safe in patients at higher risk of developing VTE. Cite this article: Bone Joint J 2017;99-B:1204–9.

Surgical Factors Associated with Prolonged Hospitalization after Reconstruction for Oncological Spine Surgery

Background:

Posterior trunk reconstruction is increasingly possible as a result of advances in spinal instrumentation, reconstructive approaches, and perioperative critical care. Extensive cases often require a muscle flap or complex closure to obliterate dead space. Postsurgical wound complications and subsequent reoperations can lead to neural injury, higher hospital costs, and longer hospitalizations. We aim to identify risk factors that are associated with increased length of stay (LOS) for patients receiving flaps to close a spinal defect.

Methods:

A single institution, retrospective cohort study was performed on all patients from 2002 to 2014 who received a muscle flap to close a spine defect. Medical and perioperative variables that were significantly associated with LOS (P < 0.05) in univariate analysis were included in a stepwise regression model.

Results:

A total of 288 cases were identified. Presence of instrumentation, preoperative chemotherapy, wound dehiscence, cerebrospinal fluid leak, partial/total flap loss, and medical morbidity occurrence were all independently associated with increased LOS in a combined multivariate model (P < 0.02 for each of the 6 variables). Importantly, Kaplan–Meier analysis demonstrated that postoperative wound dehiscence increased LOS by 12 days.

Conclusions:

Spinal tumor resections often create large cavitary defects that necessitate the use of muscle flaps for closure. Patients who have received adjuvant chemotherapy require instrumentation, or those who develop specific wound-related or medical complications are at increased risk for prolonged hospitalization after spinal reconstruction. Thus, implementing measures to mitigate the occurrence of these adverse events will reduce costs and decrease the length of hospitalization.

Factors predicting venous thromboembolism after spine surgery

BACKGROUND

A meta-analysis was performed to explore predicted factors of venous thromboembolism (VTE) after surgery in the treatment for spine degeneration diseases.

SUMMARY OF BACKGROUND DATA

Many scholars have focused on VTE after spine surgery, but as for the risk factors of VTE have not reached a consensus.

METHODS

An extensive search of literature, "spine or spinal," "degeneration," "after surgery or postoperation," and "venous thromboembolism" as key words, was performed in PubMed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases. The following variables were extracted: wearing elastic stocking, hypertension (HT), heart disease, diabetes, drinking, anticoagulant therapy, walking disability preoperation, smoking, sex, age, surgical duration, fusion versus nonfusion (lumbar fusion vs lumbar discectomy), surgical site (cervical vs lumbar), blood loss, and body mass index. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

A total of 12 studies were identified, including 34,597 patients of whom 624 patients had VTE, and the incidence of VTE was 2% in all patients who underwent spine surgery. The incidence of VTE for Asian patients was 7.5%, compared with 1% VTE for Occidental patients; the difference was significant (P < 0.0001). The pooled analysis showed that there were significant differences regarding wearing elastic stocking (odds ratio [OR] = 11.71, 95% confidence interval [CI] [1.46, 94.00], P = 0.02), walking disability preoperation (OR = 4.80, 95% CI [2.53, 9.12], P < 0.00001), surgical site (lumbar surgery) (OR = 0.23, 95% CI [0.20, 0.27], P < 0.00001), HT (OR = 1.59, 95% CI [1.21, 2.10], P = 0.001), and diabetes (OR = 2.12, 95% CI [1.09, 4.10], P = 0.03). However, there were no significant differences in blood loss, heart disease, smoking, sex, surgical duration, body mass index, surgical duration, anticoagulant therapy, wearing elastic stocking, fusion versus nonfusion, drinking, and age (all P > 0.05).

CONCLUSIONS

Based on our meta-analysis, Asian patients, patients with walking disability preoperation, patients wearing elastic stocking, patients having undergone lumbar surgery, patients with a history of HT, and patients experiencing diabetes have a higher incidence of VTE after spine surgery.

Clinical analysis of preoperative risk factors for the incidence of deep venous thromboembolism in patients undergoing posterior lumbar interbody fusion

Background

The purpose of this study aimed to assess preoperative risk factors for the incidence of deep venous thromboembolism in patients undergoing posterior lumbar interbody fusion (PLIF).

Methods

The diagnosis of preoperative deep vein thrombosis (DVT) was confirmed by Doppler ultrasonography. To examine the preoperative risk factors for DVT admitted for PLIF, comparative analysis of the DVT-positive and DVT-negative groups was done.

Results

DVT was detected in 9.4 % (269/2861) patients, including 17 proximal DVT patients (6.3 %) and 252 the distal DVT patients (93.7 %). According to multivariate logistic regression analysis, the age, preoperative D-dimer, and history of rheumatoid arthritis were significant risk factors relative to the onset of DVT after posterior lumbar surgery.

Conclusions

According to the result of our study, age, positive preoperative plasma D-dimer level, and rheumatoid arthritis had the influential impact on the incidence of DVT admitted for PLIF.

Causes of 30-day readmission after neurosurgery of the spine

OBJECT

Thirty-day readmission has been cited as an important indicator of the quality of care in several fields of medicine. The aim of this systematic review was to examine rate of readmission and factors relevant to readmission after neurosurgery of the spine.

METHODS

The authors carried out a systematic review using several databases, searches of cited reference lists, and a manual search of the JNS Publishing Group journals (Journal of Neurosurgery; Journal of Neurosurgery: Spine; Journal of Neurosurgery: Pediatrics; and Neurosurgical Focus), Neurosurgery, Acta Neurochirurgica, and Canadian Journal of Neurological Sciences. A quality review was performed using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) criteria and reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

A systematic review of 1136 records published between 1947 and 2014 revealed 31 potentially eligible studies, and 5 studies met inclusion criteria for content and quality. Readmission rates varied from 2.54% to 14.7%. Sequelae that could be traced back to complications that arose during neurosurgery of the spine were a prime reason for readmission after discharge. Increasing age, poor physical status, and comorbid illnesses were also important risk factors for 30-day readmission.

CONCLUSIONS

Readmission rates have predictable factors that can be addressed. Strategies to reduce readmission that relate to patient-centered factors, complication avoidance during neurosurgery, standardization with system-wide protocols, and moving toward a culture of nonpunitive system-wide error and “near miss” investigations and quality improvement are discussed.

Prevalence and Risk Factors of Deep Vein Thrombosis in Patients Undergoing Lumbar Interbody Fusion Surgery: A Single-Center Cross-Sectional Study

This cross-sectional study was designed to obtain the current prevalence of deep vein thrombosis (DVT) and analyze related risk factors in patients undergoing lumbar interbody fusion. Medical record data were collected from Department of Spinal Surgery, The Third Hospital of Hebei Medical University, between July 2014 and March 2015. Both univariate analysis and binary logistic regression analysis were performed to determine risk factors for DVT. A total of 995 patients were admitted into this study, including 484 men and 511 women, aged from 14 to 89 years old (median 50, IQR 19). The detection rate of lower limb DVT by ultrasonography was 22.4% (223/995) in patients undergoing lumbar interbody fusion. Notably, average VAS (visual analog scale) score in the first 3 days after surgery in the DVT group was more than that in the non-DVT group (Z = -21.69, P < 0.001). The logistic regression model was established as logit P = -13.257 + 0.056*X1 - 0.243*X8 + 2.085*X10 + 0.001*X12, (X1 = age; X8 = HDL; X10 = VAS; X12 = blood transfusion; x = 677.763, P < 0.001). In conclusion, advanced age, high postoperative VAS scores, and blood transfusion were risk factors for postoperative lower limb DVT. As well, the logistic regression model may contribute to an early evaluation postoperatively to ascertain the risk of lower limb DVT in patients undergoing lumbar interbody fusion surgery.

Prevalence and risk factors of deep vein thrombosis in patients after spine surgery: a retrospective case-cohort study

Deep vein thrombosis (DVT) is common seen in patients undergoing spine surgery. However, its prevalence and associated risk factors have not been well understood yet. This retrospective case-cohort study was designed to investigate risk factors for postoperative DVT using retrospectively collected data from department of spine surgery between 07/2013 and 07/2014. Univariate analysis and binary logistic regression analysis were used to determine risk factors for DVT. A total of 861 patients were admitted into DVT-associated analyses, including 410 males and 451 females, aged from 15 to 87 years old (median 54, IQR 18). Of them, 147 cases (17%) sustained postoperative DVT. DVT incidence was 15.9% in patients undergoing lumbar interbody fusion, 13.5% in patients treated by low-molecular-weight heparin (LMWH), while only 8.1% in patients without LMWH. However, it revealed no significant difference between LMWH group and non-LMWH group (χ² = 1.933, p = 0.164). Logistic regression equation was logit P = −4.09 + 0.05*X₁ − 0.55*X₂ + 0.41*X₃ + 1.41*X₇, (X₁ = age; X₂ = regions; X₃ = hypertension; X₇ = D-dimer). In this study, LMWH prophylaxis after spine surgery proved ineffective. Advanced age, D-dimer and hypertension have proved to be the risk factors for postoperative DVT in patients undergoing spine surgery.

Cutoff values of plasma d-dimer level in patients with diagnosis of the venous thromboembolism after elective spinal surgery

Study Design

A prospective clinical study.

Purpose

Our objective in the present study was twofold. First, we sought to evaluate the relationship between postoperative venous thromboembolism (VTE) development and concentration of D-dimer to determine the cutoff value in patients who underwent elective spinal surgery. Second, we identified the predictive risk factors for postoperative VTE.

Overview of Literature

VTE affects the general health of patients and may even cause death. Since the complications of VTE are difficult to predict, the safest and most cost effective diagnostic method should be used in order to confirm a suspected VTE event after spinal surgery.

Methods

This study was performed on 97 patients who underwent elective spinal surgery. The D-dimer assay was carried out on the day before surgery, and on days 1, 3, and 10 following surgery. VTE occurrence and D-dimer levels were compared between the VTE and the control groups.

Results

Four patients (4.1%) were diagnosed with deep vein thrombosis and one patient (1%) was diagnosed with a pulmonary embolism. The optimum D-dimer cutoff value on day 3 following surgery in the VTE group was determined to be more than 2.1 µg/mL with a sensitivity of 100% and a specificity of 80.7%. Moreover, the duration of postoperative recumbency was a significant risk factor for the development of VTE in this study.

Conclusions

We have demonstrated that postoperative D-dimer measurements in patients who underwent elective spinal surgery can provide a complementary diagnostic screening for VTE during the first week after surgery.

Prevalence and risk factors for development of venous thromboembolism after degenerative spinal surgery

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To identify the incidence and risk factors for venous thromboembolism (VTE) associated with degenerative spinal surgery procedures at the different spinal levels for various pathologies.

SUMMARY OF BACKGROUND DATA

Spinal surgery includes procedures for treatment of various pathologies at different spinal levels. There have been no studies on VTE after degenerative spinal surgery with respect to screening patients for both deep venous thrombosis and pulmonary thromboembolism (PE).

METHODS

We prospectively investigated the occurrence of VTE after degenerative spinal surgery in 459 patients who were divided into 5 groups: group 1, patients with cervical degenerative disease treated with posterior decompression; group 2, patients with cervical degenerative disease treated with instrumentation for spinal fusion; group 3, patients with thoracolumbar degenerative disease treated with instrumentation for spinal fusion; group 4, patients with lumbar spinal stenosis treated with posterior decompression; and group 5, patients with lumbar spondylolisthesis treated with 1-level posterior lumbar interbody fusion. A deep venous thrombosis and PE screening was performed for all patients. Binomial logistic regression analysis was used to assess the association of risk factors.

RESULTS

The incidence of VTE was 2.8%, 3.4%, 10.8%, 12.5%, and 10.1% in groups 1, 2, 3, 4, and 5, respectively. Female sex, advanced age, spinal level, and neurological deficits, were all risk factors. Cervical spinal surgery in particular had an associated low risk. In patients with PE, 3 of the 4 had no deep venous thrombosis, indicating that screening for PE is also needed in high-risk patients.

CONCLUSION

The prevalence of VTE after elective spinal surgery was different in each group.

LEVEL OF EVIDENCE

3.

Incidence of venous thromboembolic complications in instrumental spinal surgeries with preoperative chemoprophylaxis

OBJECTIVE

Venous thromboembolism (VTE) after spinal surgery affects a patients' postoperative recovery and also carries a mortality risk. Some studies recommended chemical prophylaxis for high-risk patients and for those after complex spinal surgeries. However, chemoprophylaxis for VTE in spinal surgery is underemployed and there is no agreement on the use of VTE prophylaxis in spinal surgery. The aim of this study was to document the incidence of VTE after an elective instrumental spinal surgery, among those receiving preoperative chemoprophylaxis as compared with patients who did not receive it.

METHODS

This study was carried out on eighty-nine patients allocated randomly to receive either low molecular weight heparin (LMWH) or no prophylaxis before elective instrumental spinal surgery. All patients received postoperative compression stockings. A compression Doppler ultrasonography was performed for all patients to detect postoperative deep vein thrombosis. In addition, further imaging studies were performed for patients suspected of VTE.

RESULTS

Three (3.3%) patients were diagnosed with VTE. One of them had received preoperative chemoprophylaxis. There were no significant difference in incidence of VTE between the two groups (p>0.95; 95% confidence interval, 0.06-8.7). Laterality of gender and postsurgical recumbence duration were all independent predictors of VTE (p=0.01 and p<0.001, respectively).

CONCLUSION

The difference in the incidence of thromboembolic complications between the two groups was not significant. Moreover, we found that preoperative prophylactic LMWH injection has no major bleeding complications altering postoperative course; still, the issue concerning the initiation time of chemoprophylaxis in spinal surgery remains unclear.