Risk factors associated with venous thromboembolism in patients undergoing spine surgery

New Perspectives on Risk Assessment and Anticoagulation in Elective Spine Surgery Patients: The Impact of Ultra-Minimally Invasive Endoscopic Surgery Techniques on Patients with Cardiac Disease

The advent of ultra-minimally invasive endoscopic spine surgery, characterized by significantly reduced surgery times, minimal blood loss, and minimal tissue trauma, has precipitated a paradigm shift in the preoperative management of patients with cardiac disease undergoing elective spine procedures. This perspective article explores how these advancements have influenced the requirements for preoperative cardiac workups and the protocols surrounding the cessation of anticoagulation and antiplatelet therapies. Traditionally, extensive cardiac evaluations and the need to stop anticoagulation and antiplatelet agents have posed challenges, increasing the risk of cardiac events and delaying surgical interventions. However, the reduced invasiveness of endoscopic spine surgery presents a safer profile for patients with cardiac comorbidities, potentially minimizing the necessity for rigorous cardiac clearance and allowing for more flexible anticoagulation management. This perspective article synthesizes current research and clinical practices to provide a comprehensive overview of these evolving protocols. It also discusses the implications of these changes for patient safety, surgical outcomes, and overall healthcare efficiency. Finally, the article suggests directions for future research, emphasizing the need for updated guidelines that reflect the reduced perioperative risk associated with these innovative surgical techniques. This discussion is pivotal for primary care physicians, surgeons, cardiologists, and the broader medical community in optimizing care for this high-risk patient population.

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.

Is it safe for the spinal metastasis patients with preoperative deep vein thrombosis to use low-molecular-weight heparin before surgery? A prospective study

Spine surgeons should weigh the risks of anticoagulants against their benefits in preventing deep venous thrombosis (DVT), as they may increase the risk of bleeding. Spinal metastasis patients undergoing decompression with fixation are at a high risk for DVT, which may occur preoperatively. Therefore, anticoagulants should be administered preoperatively. This study aimed to evaluate the safety of the administration of anticoagulants in treating spinal metastasis patients with preoperative DVT. Therefore, we prospectively investigated the prevalence of DVT in these patients. Patients who were diagnosed with preoperative DVT were included in an anticoagulant group. Subcutaneous low-molecular-weight heparin (LMWH) was administered. Patients without DVT were included in a non-anticoagulant group. Data on patient information, clinical parameters, blood test results, and bleeding complications were also collected. Moreover, the safety of anticoagulants was analyzed. The prevalence of preoperative DVT was 8.0%. None of the patients developed pulmonary thromboembolism. Furthermore, no significant differences in blood loss, drainage volume, hemoglobin levels, number of transfusions, or preoperative trans-catheter arterial embolization were observed between the two groups. None of the patients developed major bleeding. However, two patients experienced wound hematoma and one experienced incisional bleeding in the non-anticoagulant group. Therefore, LMWH is safe for spinal metastasis patients. Future randomized controlled trials should be conducted to evaluate the validity of perioperative prophylactic anticoagulation therapy in these patients.

Developing surgical skill level classification model using visual metrics and a gradient boosting algorithm

Objective

Assessment of surgical skills is crucial for improving training standards and ensuring the quality of primary care. This study aimed to develop a gradient boosting classification model (GBM) to classify surgical expertise into inexperienced, competent, and experienced levels in robot-assisted surgery (RAS) using visual metrics.

Methods

Eye gaze data were recorded from 11 participants performing four subtasks; blunt dissection, retraction, cold dissection, and hot dissection using live pigs and the da Vinci robot. Eye gaze data were used to extract the visual metrics. One expert RAS surgeon evaluated each participant's performance and expertise level using the modified Global Evaluative Assessment of Robotic Skills (GEARS) assessment tool. The extracted visual metrics were used to classify surgical skill levels and to evaluate individual GEARS metrics. Analysis of Variance (ANOVA) was used to test the differences for each feature across skill levels.

Results

Classification accuracies for blunt dissection, retraction, cold dissection, and burn dissection were 95%, 96%, 96%, and 96%, respectively. The time to complete only the retraction was significantly different among the 3 skill levels (p-value = 0.04). Performance was significantly different for 3 categories of surgical skill level for all subtasks (p-values<0.01). The extracted visual metrics were strongly associated with GEARS metrics (R2>0.7 for GEARS metrics evaluation models).

Conclusions

Machine learning (ML) algorithms trained by visual metrics of RAS surgeons can classify surgical skill levels and evaluate GEARS measures. The time to complete a surgical subtask may not be considered a stand-alone factor for skill level assessment.

Impact of Prolonged Operative Duration on Postoperative Symptomatic Venous Thromboembolic Events After Thoracolumbar Spine Surgery

OBJECTIVE

To determine the effect of operative duration on the rate of postoperative symptomatic venous thromboembolic (VTE) events in patients undergoing thoracolumbar spine fusion.

METHODS

We identified all thoracolumbar spine fusion patients between 2012 and 2021. Operative duration was defined as time from skin incision to skin closure. A 1:1 propensity match was conducted incorporating patient and surgical characteristics. Logistic regression was performed to assess predictors of postoperative symptomatic VTE events. A receiver operating characteristic curve was created to determine a cutoff time for increased likelihood of VTE.

RESULTS

We identified 101 patients with VTE and 1108 patients without VTE. Seventy-five patients with VTE were matched to 75 patients without VTE. Operative duration (339 vs. 262 minutes, P = 0.010) and length of stay (5.00 vs. 3.54 days, P = 0.008) were significantly longer in patients with a VTE event. Operative duration was an independent predictor of VTE on multivariate regression (odds ratio: 1.003, 95% confidence interval: 1.001-1.01, P = 0.021). For each additional hour of operative duration, the risk of VTE increased by 18%. A cutoff time of 218 minutes was identified (area under the curve [95% confidence interval] = 0.622 [0.533-0.712]) as an optimal predictor of increased risk for a VTE event.

CONCLUSIONS

Operative duration significantly predicted symptomatic VTE, especially after surgical time cutoff of 218 minutes. Each additional hour of operative duration was found to increase VTE risk by 18%. We also identify the impact of VTE on 90-day readmission rates, suggesting significantly higher costs and opportunity for hospital acquired conditions, in line with prior literature.

Risk factors associated with venous thromboembolism in laparoscopic surgery in non-obese patients with benign disease

INTRODUCTION

Few studies have focused on intraoperative positioning as a risk factor for venous thromboembolism (VTE). Positioning that places the legs in a dependent position may be a risk factor. We theorized that the reverse-Trendelenburg position specifically would increase the risk of postoperative VTE.

METHODS AND PROCEDURES

374,017 subjects undergoing laparoscopic surgery in the 2015-2018 NSQIP database were included. Diagnosis of cancer and BMI ≥ 30 were excluded. Subjects were grouped based on positioning: reverse-Trendelenburg (RT), supine (S), and Trendelenburg (T).

RESULTS

The RT, S, and T groups consisted of 117,887, 66,511, and 189,619 subjects, respectively. Overall median BMI was 25.7, and 82.8% of subjects were non-smokers. VTE within 30 days postoperative was seen in 0.25% RT, 0.23% S, and 0.4% T (p < 0.0001); 30-day mortality was 0.34% RT, 0.25% S, and 0.19% T (p < 0.0001). After adjusting for potential confounders and other risk factors, RT position was associated with a lower risk of VTE compared to S (OR 1.49 with 95% CI 1.16, 1.93) and T (OR 1.34 with 95% CI 1.15, 1.56) positions. VTE risk was significantly different across the three groups (p = 0.0001). Inpatient procedures had a higher VTE risk vs outpatient (OR 2.49 with 95% CI 2.10, 2.95). Increasing operative time was associated with higher VTE risk [4th (> 106 min) vs 1st (≤ 40 min) quartiles (OR 3.54 with 95% CI 2.79, 4.48)].

CONCLUSIONS

Among other risk factors, inpatient procedures and longer operative times are associated with higher VTE risk in laparoscopic surgery performed for benign disease in non-obese patients. The risk was significantly different across the three positioning groups with lowest risk in the RT group and highest risk in the S group.

Construction and verification of a nomogram predicting the risk of preoperative deep vein thrombosis progression after elective spine surgery

OBJECTIVE

This study aimed to construct and verify a useful nomogram that predicts the risk of preoperative deep vein thrombosis (DVT) progression after elective spine surgery.

METHODS

Data of patients were collected from 366 patients with preoperative DVT who underwent elective spine surgery at our hospital between July 2017 and May 2022. The least absolute shrinkage and selection operator method combined with multivariable logistic regression analysis were applied to select features for the preoperative DVT progression risk model. The model's capability was evaluated using the concordance index (C-index), calibration curve, and receiver operating characteristic (ROC) curve. The decision curve and bootstrapping were used to analyze the clinical value of the nomogram.

RESULT

A total of 366 DVT patients were enrolled in this study. Preoperative DVT progression after elective spine surgery was 24.04% (88 cases). Among these patients, 86 patients had thrombosis extending into a proximal vein or appearing in a different branch of the vein, either ipsilateral or contralateral, and two had a symptomatic pulmonary embolism. D-dimer, lower extremity varicosities, hyperlipidemia, lower limb paralysis, and operation time were among the predictors in the nomogram. Furthermore, the C-index of the prediction nomogram was 0.805 (95％ CI: 0.754-0.856), with an interval bootstrapping validation of 0.786 and an area under the ROC curve value of 0.800. According to the calibration curves and decision curve analysis, the nomogram could accurately predict the probability of preoperative DVT progression after elective spine surgery.

CONCLUSION

The advantages of the nomogram included the unique discrimination capability, clinical utility, and predictive accuracy, which was beneficial for clinicians to distinguish high-risk groups of DVT progression after elective spine surgery and formulate relevant prevention measures.

Predictive risk factors for venous thromboembolism in neurosurgical patients: A retrospective analysis single center cohort study

Background

Venous thromboembolism (VTE) has a major effect on morbidity and mortality in neurosurgical patients. However, identifying risk factors that may be useful in practice is a challenge. The purpose of this study was to investigate the incidence and determine the predictors of VTE in patients undergoing neurosurgery.

Materials and methods

This retrospective, single-center cohort study was conducted on adult patients admitted to a private hospital for a primary elective neurosurgical procedure between January 2015 and December 2020. Univariate analysis was used to examine clinical factors, and multivariable regression analysis was used to identify predictors of VTE. The area under the receiver-operating characteristic (AUROC) curve demonstrated the fitting model and discrimination power.

Results

A total of 350 patients who underwent neurological surgery were identified. There were 26 patients (7.4%) with VTE. The final predictors were found to be statistically significant in the multivariate binary logistic regression analysis, including non-Asian populations (p value < 0.001, odds ratio [OR]: 6.11, 95% confidence interval [CI] = 2.20–16.89), lack of postoperative ambulation (p value = 0.009, OR: 9.25, 95% CI = 1.17–48.83), and septic shock complication (p value = 0.001, OR: 5.36, 95% CI = 1.46–19.62). The AUROC was 0.708 (95% CI 0.61–0.80).

Conclusion

Although the incidence of VTE in patients receiving neurosurgery is minimal, it is also higher in non-Asian patients, those who lack of postoperative ambulation, and patients with septic shock complications. This approach may be useful to predict thromboembolism in neurosurgical patients. External validation of the prognostic model requires more investigation.

•

Venous thromboembolism (VTE) complications can be a major cause of morbidity and even death in neurosurgical patients.

•

The standard therapy for the appropriate prophylaxis remains unclear.

•

Whether or not to use pharmacological prophylaxis is determined by a higher-risk category of individuals.

•

Based on information from risk factors, it may be a benefit guide for proper VTE prophylaxis.

Complications in spinal tumor surgery (review of literature)

Combined anterior and posterior approaches are required in spinal tumor surgery and considered highly invasive. Anatomical and physiological features of the surgical intervention area should be taken into consideration as well. Thus, these criteria reflect the severity of intraoperative complications during the surgical treatment of spinal tumors. The authors reviewed the scientific literature on the frequency and nature of complications in surgical interventions for spinal tumors.The most significant risk factors for intraoperative complications have been considered, the main of which are: the proximity of the location of the main vessels and viscera, the development of postoperative liquorrhea, as well as surgical site infection. Based on the studied information, we presented the methods of prevention and surgical tactics options in complications.

Risk Factors for Venous Thrombosis after Spinal Surgery: A Systematic Review and Meta-analysis

Background. Venous thrombosis, comprising DVT and PE, is an orthopedic condition that may be fatal after surgery. This study’s purpose was to analyze risk factors for venous thrombosis following spine surgery to help guide treatment prophylaxis. Methods. A computer searched English databases such as PubMed, Web of Science, Embase, Cochrane Library, and Google Academic for relevant publications after spinal surgery. Preoperative walking difficulties, hypertension, diabetes, heart disease, preoperative bleeding volume, etc., were all examined using the NOS scale. Data were analyzed using Review Manager 5.3 software. An analysis was done. Due to the study’s differences, the data was compiled using fixed effects or random effects models. Results. A total of 25 studies were considered, with a total of 1,927,781 individuals after spine surgery, including 7843 patients with venous thrombosis. The included literatures had NOS scores ranging from 5 to 8. According to the findings of the meta-analysis, the age of patients with venous thrombosis after spinal surgery ( $\text{OR}=7.53$ , 95% CI (6.73, 8.33)), blood loss ( $\text{OR}=-141.79$ , 95% CI (-154.68, -128.9), $P=0.00001$ ), and operation time ( $\text{OR}=76.93$ , 95% CI (73.17, 80.86), $P=0.00001$ ) were higher than those without; diabetes mellitus (OR =1.23, 95% CI (1.12, 1.34), $P=0.00001$ ) and walking disability history ( $\text{OR}=2.97$ , 95% CL (1.77, 4.98), $P=0.0001$ ) increased the incidence of postoperative venous thrombosis. Conclusion. High age, female, spinal fusion, big volume blood loss patients, operation time, and hypertension, diabetes, and walking issue are all risk factors for venous thrombosis following surgery.

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.

[The new algorithm for stratification of the risk of venous thromboembolic events in elective neurosurgery and its prognostic significance]

Early identification of risk groups is essential for effective and target prevention of venous thromboembolic events (VTE) in all areas of surgery. For this purpose, the authors has developed and put into practice an algorithm distinguishing the groups of low, moderate and high risk of VTE among neurosurgical patients.

OBJECTIVE

To assess predictive value of the developed algorithm for elective neurosurgical interventions.

MATERIAL AND METHODS

The study included 7914 patients who underwent surgery between January 2018 and December 2019. According to the algorithm, we identified the groups of low (1536 (19%) patients), moderate (4554 (58%) patients) and high risk (1824 (23%) patients). Moreover, patients were divided into subgroups depending on surgical procedure. We analyzed the incidence of VTE and mortality in all groups.

RESULTS. INCIDENCE

Of VTE with a 95% confidence interval in the low-risk group was 0.65% [0.26; 1.04], in the moderate risk group - 1.82% [1.47; 2.24], in the high-risk group - 12.61% [11.02; 14.09]. When comparing various surgical interventions, we revealed more common VTE after vascular microsurgery (15.62%), in patients with brain tumors (12.63%) and spinal cord tumors (6.52%).

CONCLUSION

The risk stratification algorithm has demonstrated its convenience and significant predictive value for determining the risk of VTE among elective neurosurgical patients. In addition, different incidence of VTE was demonstrated in patients with various neurosurgical diseases.

Incidence and Risk Factors for Postoperative Venous Thromboembolic Events in Patients Undergoing Cervical Spine Surgery

STUDY DESIGN

This was a retrospective database study.

OBJECTIVE

The objective of this study was to investigate preoperative risk factors and incidence of venous thromboembolic events (VTEs) after cervical spine surgery.

SUMMARY OF BACKGROUND DATA

VTEs are preventable complications that may occur after spinal procedures. Globally, VTEs account for a major cause of morbidity and mortality. Preoperative risks factors associated with increased VTE incidence after cervical spine surgery have not been well-characterized.

MATERIALS AND METHODS

Patients undergoing anterior cervical discectomy and fusion (ACDF); posterior cervical fusion (PCF); discectomy; and decompression from 2007 to 2017 were identified using the PearlDiver Database. International Classification of Diseases (ICD) Ninth and 10th Revision codes were used to identify VTEs at 1 week, 1 month, and 3 months postoperative as well as preoperative risk factors.

RESULTS

Risk factors with the highest incidence of VTE at 3 months were primary coagulation disorder [ACDF=7.82%, odds ratio (OR)=3.96; decompression=11.24%, OR=3.03], central venous line (ACDF=5.68%, OR=2.11; PCF=12.58%, OR=2.27; decompression=10.17%, OR=2.80) and extremity paralysis (ACDF=6.59%, OR=2.73; PCF=18.80%, OR=2.99; decompression=11.86, OR=3.74). VTE incidence at 3 months for populations with these risks was significant for all surgery types (P<0.001) with the exception of patients with primary coagulation disorder who underwent PCF. Tobacco use had the lowest VTE incidence for all surgery types.

CONCLUSIONS

The total cumulative incidence of VTEs at 3-month follow-up was 3.10%, with the highest incidence of VTEs occurring within the first postoperative week (0.65% at 1 wk, 0.61% at 1 mo, 0.53% at 3 mo for ACDF; 2.56% at 1 wk, 1.93% at 1 mo, 1.45% at 3 mo for PCF; 1.37% at 1 wk, 0.93% at 1 mo, 0.91% at 3 mo for decompression). Several preoperative risk factors were found to be significant predictors for postoperative VTEs and can be used to suggest those at increased risk as well as decrease the incidence of preventable VTEs after cervical spine surgery.

LEVEL OF EVIDENCE

Level III.

Perioperative Care of Patients Undergoing Major Complex Spinal Instrumentation Surgery: Clinical Practice Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care

Evidence-based standardization of the perioperative management of patients undergoing complex spine surgery can improve outcomes such as enhanced patient satisfaction, reduced intensive care and hospital length of stay, and reduced costs. The Society for Neuroscience in Anesthesiology and Critical Care (SNACC) tasked an expert group to review existing evidence and generate recommendations for the perioperative management of patients undergoing complex spine surgery, defined as surgery on 2 or more thoracic and/or lumbar spine levels. Institutional clinical management protocols can be constructed based on the elements included in these clinical practice guidelines, and the evidence presented.

Incidence, risk factors and clinical course of pyogenic spondylodiscitis patients with pulmonary embolism

Purpose

In patients with pyogenic spondylodiscitis, surgery is considered the treatment of choice to conduct proper debridement, stabilise the spine and avoid extended bed rest, which in turn is a risk factor for complications such as deep vein thrombosis and pulmonary embolism.

Methods

We conducted a retrospective clinical study with analysis of a group of 99 patients who had undergone treatment for pyogenic discitis at our institution between June 2012 and August 2017. Included parameters were age, sex, disease pattern, the presence of deep vein thrombosis, resuscitation, in-hospital mortality, present anticoagulation, preexisting comorbidities, tobacco abuse, body mass index, microbiological germ detection and laboratory results.

Results

Among the analysed cohort, 12% of the treated patients for pyogenic spondylodiscitis suffered from a radiologically confirmed pulmonary embolism. Coronary heart disease (p < 0.01), female sex (p < 0.01), anticoagulation at admission (p < 0.01) and non-O blood type (p < 0.001) were associated with development of pulmonary embolism. Pulmonary embolism was significantly associated with resuscitation (p < 0.005) and deep vein thrombosis (p < 0.001). Neurosurgery was not associated with increased risk for pulmonary embolism compared to conservative-treated patients (p > 0.05).

Conclusion

Surgery for pyogenic spondylodiscitis was not associated with an elevated risk of pulmonary embolism in our analysis. However, we describe several risk factors for pulmonary embolism in this vulnerable cohort. Prospective studies are necessary to improve prevention and postoperative management in patients with pyogenic spondylodiscitis.

Racial differences in symptomatic postoperative venous thromboembolism rates after major oncologic resection

BACKGROUND

Recent evidence suggests an increased incidence of venous thromboembolism among cancer patients of Black race. This study aimed to determine whether Black patients undergoing major oncologic resection experience increased rates of postoperative venous thromboembolism.

METHODS

A cohort study of patients who underwent major oncologic resection was performed using American College of Surgeons National Surgical Quality Improvement Program (2016-2018). Primary outcome was venous thromboembolism within 30 days of surgery. Multivariable logistic regression was performed to evaluate the independent association of race and venous thromboembolism.

RESULTS

Of 91,707 patients, 67.7% were White, 9.5% Black, and 22.9% other race. Venous thromboembolism rates differed slightly by race: 2.2% among Whites, 2.4% Blacks, and 1.8% other (P = .002). Black patients were older, with higher rates of obesity, diabetes, and smoking. By multivariable logistic regression, risk of venous thromboembolism was lower among patients of other compared with White race (odds ratio 0.83; 95% confidence interval, 0.74-0.94). There was no difference in odds of venous thromboembolism among Black relative to White patients (odds ratio 1.08; 95% confidence interval, 0.93-1.26). When stratified by age, rates of venous thromboembolism were >50% higher among Black patients older than 75 years compared with White patients (odds ratio 1.54; 95% confidence interval, 1.17-2.03).

CONCLUSION

Despite evidence that Black patients with cancer experience higher rates of venous thromboembolism, they do not appear to have an increased risk in the postoperative period.

The risks and benefits of early venous thromboembolism prophylaxis after elective spinal surgery: A single-centre experience

BACKGROUND

There is a wide ranging incidence of venous thromboembolism after surgery and it continues to be a major cause of morbidity after spinal procedures.This study's aim was to investigate the relationship between timing and administration of venous thromboembolism (VTE) pharmacologic chemoprophylaxis after spinal surgery and the resulting VTE and bleeding complications by reviewing current practices and outcomes at a high-volume single institution to better define opportunities for perioperative intervention to prevent VTE without increasing bleeding complications.

METHODS

All patients who underwent elective one or two-stage lumbar spinal fusion procedures were identified. A logistic regression was used to evaluate (1) risk of symptomatic VTE within 30 days of surgery and (2) bleeding-related complications. The odds of developing a VTE as well as bleeding-related complications were compared among the three treatment groups: no chemoprophylaxis, chemoprophylaxis < 24h of surgery and chemoprophylaxis given > 24h post-surgery.

RESULTS

When adjusted for doses administered, the odds of developing a postoperative VTE within 30 days were 0.189 (95% confidence interval (0.044, 0.808)) in patients who received anticoagulation < 24h postoperatively, compared to those who received no anticoagulation (p = 0.025). There was no difference in bleeding rates.

CONCLUSION

Patients undergoing elective spinal surgery who received anticoagulation within 24h of the conclusion of their procedure had an 81% reduction in the odds of developing a deep vein thrombosis within 30 days with no significant difference in bleeding complications.

[Incidence and risk factors of venous thromboembolic events after resection of various brain tumors]

Venous thromboembolic events (VTE) can significantly complicate postoperative period in neurosurgical patients. It is known that patients with brain tumors are especially susceptible to VTE.

OBJECTIVE

To determine the incidence and risk factors of VTE in patients with various brain tumors.

MATERIAL AND METHODS

All patients with brain tumors underwent surgery in 2019 (n=610). They were divided into the groups depending on tumor type: sellar region, intracerebral, extracerebral neoplasms and metastases. All patients underwent screening and prevention of VTE in accordance with the protocol accepted in the hospital. We analyzed the incidence of VTE in each group and significance of various risk factors.

RESULTS

Overall incidence of VTE was 14.9% (91 cases). Deep vein thrombosis (DVT) was the most common - 85 cases (93.4%). Less common events were DVT combined with pulmonary embolism (PE) (n=5, 5.5%) and PE alone (n=1; 1.1%). PE caused death in 2 cases (0.3%). In patients with sellar tumors, incidence was 21.7% [13.4%; 29.35%], among intracerebral tumors - 13.8% [9.04%; 18.62%], extracerebral neoplasms - 15.4% [11.02%; 19.69%], metastases - 7.9% [1.32%; 11.84%]. Univariate and multivariate analysis revealed some risk factors of VTEs such as gender, age, surgery time, length of ICU-stay over 12 hours, body mass index >30 kg/m². Moreover, risk factors have different significance in patients with different types of tumors.

CONCLUSION

In this study, we found a high incidence of VTE among patients with brain tumors. Incidence and risk factors of VTE depend on the type of tumor.

Nomogram for Predicting the Postoperative Venous Thromboembolism in Spinal Metastasis Tumor: A Multicenter Retrospective Study

Introduction

Venous thromboembolism can be divided into deep vein thrombosis and pulmonary embolism. These diseases are a major factor affecting the clinical prognosis of patients and can lead to the death of these patients. Unfortunately, the literature on the risk factors of venous thromboembolism after surgery for spine metastatic bone lesions are rare, and no predictive model has been established.

Methods

We retrospectively analyzed 411 cancer patients who underwent metastatic spinal tumor surgery at our institution between 2009 and 2019. The outcome variable of the current study is venous thromboembolism that occurred within 90 days of surgery. In order to identify the risk factors for venous thromboembolism, a univariate logistic regression analysis was performed first, and then variables significant at the P value less than 0.2 were included in a multivariate logistic regression analysis. Finally, a nomogram model was established using the independent risk factors.

Results

In the multivariate logistic regression model, four independent risk factors for venous thromboembolism were further screened out, including preoperative Frankel score (OR=2.68, 95% CI 1.78-4.04, P=0.001), blood transfusion (OR=3.11, 95% CI 1.61-6.02, P=0.041), Charlson comorbidity index (OR=2.01, 95% CI 1.27-3.17, P=0.013; OR=2.29, 95% CI 1.25-4.20, P=0.017), and operative time (OR=1.36, 95% CI 1.14-1.63, P=0.001). On the basis of the four independent influencing factors screened out by multivariate logistic regression model, a nomogram prediction model was established. Both training sample and validation sample showed that the predicted probability of the nomogram had a strong correlation with the actual situation.

Conclusion

The prediction model for postoperative VTE developed by our team provides clinicians with a simple method that can be used to calculate the VTE risk of patients at the bedside, and can help clinicians make evidence-based judgments on when to use intervention measures. In clinical practice, the simplicity of this predictive model has great practical value.

Incidence and risk factors predicting deep venous thrombosis of lower extremity following spinal fractures

The aim of this study was to investigate the presence of preoperative DVT following spinal fracture and the association between the presence of DVT and risk factors. Ultrasonography and blood analyses were performed preoperatively in patients diagnosed with spinal fracture between October 2014 and December 2018. Univariate analyses were performed on the data of demographics, comorbidities, location of injury, spinal cord injury (SCI) grading and laboratory biomarkers. The receiver operating characteristic (ROC) curve analysis was employed to obtain the optimal D-dimer cut-off value for diagnosis. In total, 2432 patients with spinal fractures were included, among whom 108 (4.4%) patients had preoperative DVTs. The average interval between fracture and initial diagnosis of DVT was 4.7 days (median, 2 days), ranging from 0 to 20 days; 78 (72.2%) were diagnosed within 7 days after injury and 67 (62.0%) within 3 days; 19 (17.5%) patients had proximal vein involved and 89 (82.4%) presented in distal veins. Multivariate logistic regression suggested six risk factors independently correlated to DVT, including delay to DUS (in each day) (odds ratio [OR] = 1.11), ASA class III-IV (OR = 2.36), ASIA grade (A/B) (OR = 2.36), ALB < 3.5 g/dL (OR = 2.08), HDL-C < 1.1 mmol/L (OR = 1.68) and D-Dimer > 1.08 µg/ml (OR = 2.49).

A predictive model of preoperative risk factors for venous thromboembolism after fusion for degenerative conditions of the thoracolumbar spine

BACKGROUND

The purpose of this study was to identify preoperative risk factors for VTE and develop a predictive model that can be integrated into electronic health records (EHRs).

METHODS

Retrospective review of patients undergoing thoracolumbar fusion from 2016 to 2018 in the National Surgical Quality Improvement Program database was performed.

RESULTS

Increasing age, BMI, and several other factors were significant predictors of increased risk for postoperative VTE. The predictive model had an area under the curve of 0.683, indicating acceptable discrimination.

DISCUSSION

Our findings build upon previous studies by presenting a model equation that can be rapidly integrated into EHRs for validation.

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.

A Comparison of the Elixhauser and Charlson Comorbidity Indices: Predicting In-Hospital Complications Following Anterior Lumbar Interbody Fusions

OBJECTIVE

The Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI) are commonly used measures that use administrative data to characterize a patient's comorbidity burden. The purpose of this study was to compare the ability of these measures to predict outcomes following anterior lumbar interbody fusion.

METHODS

The National Inpatient Sample was queried for all ALIF procedures between 2013 and 2014. The area under the receiver operating curve (AUC) was used to compare the ECI and CCI in their ability to predict postoperative complications when incorporated into a base model containing age, sex, race, and primary payer. Percent superiority was computed using AUC values for ECI, CCI, and base models.

RESULTS

A total of 43,930 hospitalizations were included in this study. The ECI was superior to the CCI and baseline models in predicting minor (AUC 71 vs. 0.66, P < 0.0001) and major (AUC 0.74 vs. 0.67, P < 0.0001) complications. When evaluating individual complications, the ECI was superior to the CCI in predicting airway complications (65% superior, AUC 0.85 vs. 0.72, P = 0.0001); hemorrhagic anemia (83% superior, AUC 0.71 vs. 0.66, P < 0.0001); myocardial infarction (76% superior, AUC 0.86 vs. 0.67, P < 0.0001); cardiac arrest (75% superior, AUC 0.85 vs. 0.67, P < 0.0001); pulmonary embolism (105% superior, AUC 0.91 vs. 0.71, P < 0.0001); and urinary tract infection (43% superior, AUC 0.76 vs. 0.73, P = 0.046).

CONCLUSIONS

The ECI was superior to the CCI in predicting 6 of the 15 complications analyzed in this study. Combined with previous results, the ECI may be a better predictive model in spine surgery.

Venous Duplex Ultrasound Surveillance in the Neurosurgical Population: A Single-Center Quality Improvement Initiative

BACKGROUND

Venous thromboembolism (VTE) represents a significant source of morbidity and mortality in the inpatient population and is considered a leading preventable cause of death among inpatients. Neurosurgical inpatients are of particular interest because of the greater rates of immobility, steroid use, and potential consequences of postoperative hemorrhage. A consensus protocol for VTE screening in this population has not yet been developed, and institutional protocols vary widely.

METHODS

We performed a retrospective review of lower extremity venous duplex ultrasonography (VDUS) usage at our institution and applied this information to the development of a neurosurgery department protocol, with consideration of high-risk patient risk factors and indications for VDUS ordering. We then implemented this protocol, which consisted of preoperative screening of patients at high risk of VTE and limited postoperative surveillance, for a 6-month period and compared VDUS usage and VTE occurrence.

RESULTS

Preoperative VDUS screening before nonemergent neurosurgical procedures in high-risk patients with active cancer, an inability to ambulate, or a history of deep vein thrombosis (DVT) identified proximal DVTs that were then treated. Postoperative routine surveillance VDUS scans only diagnosed incidental isolated calf DVT for which no clinically relevant sequelae occurred. Overall, postoperative surveillance VDUS usage decreased significantly (66.9% vs. 13.5%; P = 0.001).

CONCLUSIONS

Our findings lend support to preoperative screening of high-risk patients and suggest that routine postoperative VDUS surveillance of asymptomatic patients is unnecessary.

Does minimally invasive spine surgery reduce the rate of perioperative medical complications? A retrospective single-center experience of 1435 degenerative lumbar spine surgeries

PURPOSE

It is unclear if minimally invasive techniques reduce the rate of perioperative complications when compared to traditional open approaches to the lumbar spine. Our aim was to evaluate perioperative complications in patients that underwent MIS and conventional open techniques for degenerative lumbar pathology.

METHODS

A retrospective review of a prospectively collected database identified 1435 patients that underwent surgery for degenerative lumbar pathology from January 2013-2016. We evaluated the rates of deep vein thrombosis, pulmonary embolism, urinary tract infection, and pneumonia. Groups were analyzed based on decompression alone as compared with decompression and fusion for both MIS and traditional open techniques.

RESULTS

Patients that underwent traditional open lumbar decompression surgery were more likely to develop a DVT (P = .01) than those undergoing MIS decompression. There was no significant difference in rates of PE (P = .99), UTI (P = .24), or pneumonia (P = .56). Patients that underwent traditional open lumbar fusion surgery compared to MIS fusion were also more likely to have a PE (P = .03). There was no significant difference in rates of DVT (P = .22), UTI (P = .43), or pneumonia (P = .24).

CONCLUSION

Minimally invasive spinal surgery was found to reduce the rate of DVT for decompression surgeries and reduce the rate of PE for fusion surgeries.

Comparison of inpatient versus post-discharge venous thromboembolic events after spinal surgery: A single institution series of 6869 consecutive patients

STUDY DESIGN

retrospective chart review.

OBJECTIVE

We aimed to determine the perioperative risk factors that lead to inpatient or post-discharge venous thromboembolism (VTE) events after spinal surgery.

SUMMARY OF BACKGROUND DATA

While many studies relate the risk factors in a post-surgical setting to the incidence of VTE, this study aims to separate these VTE into inpatient and post-discharge categories to examine timing and risk factors.

METHODS

We analyzed 6869 patients from 2009 to 2015 using Current Procedural Technology codes from a single tertiary academic institution. Patients were stratified based on occurrence and setting of VTE then controlled for perioperative characteristics with exclusion criteria being patients undergoing minor spine surgeries or secondary procedures.

RESULTS

In 170 VTE events, these factors were associated with increased risk for: Inpatient DVT only: IVC filter (OR 6.380 [3.414-11.924]), longer length of hospital stay (OR 1.083 [1.047-1.120]), a prior history of DVT (OR 3.640 [1.931-6.856]). Post-discharge DVT only: history of PE (OR 45.142 [6.785-300.351]), having a corpectomy (OR 26.670 [3.477-204.548]), and having an osteotomy (OR 18.877 [1.129-315.534]). Inpatient PE only: surgery >4 h (OR 30.820, p < 0.001), fracture (OR 6.913, p = 0.004), IVC filter (OR 3.135, p = 0.029). Post-discharge PE only: corpectomy (OR 541.271, p = 0.009), foraminotomy (OR 40.137, p = 0.013), EBL > 500cc (OR 2467.798, p = 0.002). Time to onset of VTE events was significantly longer for patients undergoing osteotomy (7.43 days) than for patients with fracture (4.28 days), which is consistent with our findings that fracture was an independent predictor of inpatient VTE, and osteotomy was an independent predictor of post-discharge VTE (p = 0.018).

CONCLUSIONS

Time-to-VTE varies between types of surgeries. Some risk factors are independently associated with VTE at all times during the 30-day postoperative period, while other factors are only associated with either inpatient or post-discharge VTE. Those patients with high-risk features for post-discharge VTE merit increased study for thromboprophylaxis management.

Postoperative Venous Thromboembolism in Extramedullary Spinal Tumors

Context:

Venous thromboembolism (VTE), including deep-vein thrombosis (DVT) and pulmonary embolism (PE), is the fatal complication following spine surgery and the appropriate perioperative prophylaxis is still debated.

Aims:

The aim of this study is to evaluate the incidence of along with risk factors for postoperative VTE in surgically treated extramedullary spinal tumor patients.

Setting and Designs:

The study design involves single institute and retrospective cohort study.

Subjects and Methods:

The cohort database was reviewed between the periods of January 2014 and June 2019. Patients undergoing surgery for spine tumor, extradural tumor, and intradural extramedullary were consecutively collected.

Statistical Analysis Used:

The incidence of VTE and clinical factors reported to be associated with VTE were identified, and then analyzed with an appropriate Cox regression model.

Results:

The study identified 103 extramedullary spinal tumor patients. Three patients (2.9%) were diagnosed with a proximal leg DVT, while symptomatic PE did not identify. Risk factors associated with DVT occurrence were as follows: operative time ≥8 h (Hazard ratio [HR] 13.98, P = 0.03) and plasma transfusion (HR 16.38, P = 0.02), whereas plasma transfusion was the only significant factor, after multivariate analysis (HR 11.77, P = 0.05).

Conclusions:

Patients who underwent surgery for extramedullary spinal tumors showed a 2.9% incidence of DVT. The highest rate of DVT was found in patients who received plasma transfusion. More attention should be paid on perioperative associated factors for intensive prevention coupled with early screening in this group.

Anesthetic Considerations in Cobb Syndrome: A Case Report

Cutaneomeningospinal angiomatosis, popularly known as Cobb syndrome, is a rare clinical disorder predominantly presenting with a vascular skin lesion and a spinal angioma at the same dermatomal level. Several case reports and case series have reported on the surgical management of this syndrome, but we failed to find any information about its anesthetic considerations in the Medline database. Our case report describes the perioperative anesthetic management of a 46-year-old man with Cobb syndrome.

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.

Predictors of Hospital-Acquired Conditions Are Predominately Similar for Spine Surgery and Other Common Elective Surgical Procedures, With Some Key Exceptions

STUDY DESIGN

Retrospective review of a prospectively collected database.

OBJECTIVE

To predict the occurrence of hospital-acquired conditions (HACs) 30-days postoperatively and to compare predictors of HACs for spine surgery with other common elective surgeries.

METHODS

Patients ≥18 years undergoing elective spine surgery were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2013. Outcome measures included any HACs: superficial or deep surgical site infection (SSI), venous thromboembolism (VTE), urinary tract infection (UTI). Spine surgery patients were compared with those undergoing other common procedures. Random forest followed by multivariable regression analysis was used to determine risk factors for the occurrence of HACs.

RESULTS

A total of 90 551 elective spine surgery patients, of whom 3021 (3.3%) developed at least 1 HAC, 1.4% SSI, 1.3% UTI, and 0.8% VTE. The occurrence of HACs for spine patients was predicted with high accuracy (area under the curve [AUC] 77.7%) with the following variables: female sex, baseline functional status, hypertension, history of transient ischemic attack (TIA), quadriplegia, steroid use, preoperative bleeding disorders, American Society of Anesthesiologists (ASA) class, operating room duration, operative time, and level of residency supervision. Functional status and hypertension were HAC predictors for total knee arthroplasty (TKA), bariatric, and cardiothoracic patients. ASA class and operative time were predictors for most surgery cohorts. History of TIA, preoperative bleeding disorders, and steroid use were less predictive for most other common surgical cohorts.

CONCLUSIONS

Occurrence of HACs after spine surgery can be predicted with demographic, clinical, and surgical factors. Predictors for HACs in surgical spine patients, also common across other surgical groups, include functional status, hypertension, and operative time. Understanding the baseline patient risks for HACs will allow surgeons to become more effective in their patient selection for surgery.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Incidence and Risk Factors for Venous Thromboembolism After Spine Surgery in Korean Patients

BACKGROUND

Data regarding the incidence of venous thromboembolism (VTE) after spine surgery are scarce. Identifying ideal candidates for pharmacologic thromboprophylaxis and balancing the risk of thromboembolic complications against the risk of permanent neurologic deficits from a spinal epidural hematoma (SEH) are difficult. Even guidelines cannot suggest the standard of thromboprophylaxis.

OBJECTIVES

This study aimed to identify the incidence of and risk factors for VTE after spine surgery in the Korean population. In addition, the rate of pharmacoprophylaxis and the incidence of SEH after spine surgery were analyzed.

METHODS

The study cohort was generated by extracting patients with disease codes of spine surgery and VTE from the Health Insurance Review & Assessment Service National Inpatient Sample in 2014. After analyzing the incidence of VTE after spine surgery, a univariate comparison was performed to examine the possible relationship between the incidence of VTE and the independent variable. Variables found to be significant were included in a multivariable analysis model for further analysis.

RESULTS

The incidence of VTE was 2.09% among all 21,261 patients who had spine surgery, and prophylaxis was applied to 7.89% of all patients who had spine surgery. Comorbidities and surgery-related risk factors were venous disease, cancer, respiratory disease, prolonged surgery hours, and increased total blood loss. Hospital-related risk factors were the location and hospital size.

CONCLUSIONS

On the basis of the incidence of VTE and the risk factors, more active prophylaxis is suggested for patients in the Korean population who undergo spine surgery.

Venous Thromboembolism After Degenerative Spine Surgery: A Nationwide Readmissions Database Analysis

BACKGROUND

Venous thromboembolism (VTE) is an appreciable burden on health care. The protracted recumbency experienced by many spinal patients juxtaposed with concerns for postoperative hemorrhage from early anticoagulation results in conflicting stances regarding chemoprophylaxis. Identifying risk factors associated with VTE is therefore instrumental in guiding management.

OBJECTIVE

To identify VTE risk factors in patients undergoing degenerative spine surgery.

METHODS

The Nationwide Readmissions Database was searched for adults undergoing spine surgery for degenerative diseases between 2010 and 2014. The 30-day and 90-day VTE incidence was estimated from readmissions with new VTE diagnoses. A multivariate survey-adjusted logistic regression model was used to identify variables associated with VTE diagnoses on readmission.

RESULTS

Of 838,507 degenerative spine cases queried, 3499 patients (0.42%) were readmitted with a VTE diagnosis within 30 days and 4321 patients (0.62%) were readmitted within 90 days. In multivariate analysis, steroids were independently associated with a higher likelihood of readmission with VTE at both 30 days (odds ratio, 1.58; P < 0.001) and 90 days (odds ratio, 1.97; P < 0.001). Significant associations were also identified with thoracolumbar surgery, length of stay, and discharge to institutional care.

CONCLUSIONS

The incidence of readmission with VTE diagnoses in spine surgery is low. However, their devastating consequences underscore the need to identify those patients deemed high risk. These patients include those having thoracolumbar surgery, of advanced age, with prolonged length of stay, using corticosteroids, and with a disposition to institutional care (e.g., skilled nursing facility or long-term acute care). Given the association between steroids and VTE, clinicians should be judicious about perioperative administration despite their obvious antiinflammatory benefits.

Deep Vein Thrombosis After Complex Posterior Spine Surgery: Does Staged Surgery Make a Difference?

STUDY DESIGN

Retrospective review of a prospectively collected database.

OBJECTIVE

To assess the incidence of deep vein thrombosis (DVT) associated with single- versus multistage posterior-only complex spinal surgeries.

SUMMARY OF BACKGROUND DATA

Dividing the physiologic burden of spinal deformity surgery into multiple stages has been suggested as a potential means of reducing perioperative complications. DVT is a worrisome complication owing to its potential to lead to pulmonary embolism. Whether or not staging affects DVT incidence in this population is unknown.

METHODS

Consecutive patients undergoing either single- or multistage posterior complex spinal surgeries over a 12-year period at a single institution were eligible. All patients received lower extremity venous duplex ultrasonographic (US) examinations 2 to 4 days postoperatively in the single-stage group and 2 to 4 days postoperatively after each stage in the multistage group. Multivariate logistic regression was used to assess the independent contribution of staging to developing a DVT.

RESULTS

A total of 107 consecutive patients were enrolled-26 underwent multistage surgery and 81 underwent single-stage surgery. The single-stage group was older (63 years vs. 45 years; p < .01) and had a higher Charlson comorbidity index (2.25 ± 1.27 vs. 1.23 ± 1.58; p < .01). More multistage patients had positive US tests than single-stage patients (5 of 26 vs. 6 of 81; 19% vs. 7%; p = .13). Adjusting for all the above-mentioned covariates, a multistage surgery was 8.17 (95% CI 0.35-250.6) times more likely to yield a DVT than a single-stage surgery.

CONCLUSIONS

Patients who undergo multistage posterior complex spine surgery are at a high risk for developing a DVT compared to those who undergo single-stage procedures. The difference in DVT incidence may be understated as the multistage group had a lower pre- and intraoperative risk profile with a younger age, lower medical comorbidities, and less per-stage blood loss.

Risk Factors and Associated Complications of Symptomatic Venous Thromboembolism in Patients with Craniotomy for Meningioma

OBJECTIVE

Patients undergoing surgical resection of meningioma are at increased risk for developing venous thromboembolism (VTE). The aim of this study was to assess occurrence of VTE in patients who underwent surgical resection of meningioma to determine risk factors and associated complications of VTE.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project database from 2012 to 2015 was reviewed for patients who had undergone meningioma resection according to primary Current Procedural Terminology codes and International Classification of Diseases, Ninth Revision.

RESULTS

The study included 5036 patients with meningioma. Rate of VTE was 3.38%, with pulmonary embolism rate of 1.47% and deep venous thrombosis rate of 2.42%. During the first 30 days after surgery, patients with VTE had a mortality rate of 5.88% compared with 1.15% for patients without VTE. Multivariate binary logistic regression analysis determined 5 risk factors for VTE,: age ≥60 years, American Society of Anesthesiologists classification III, operative time ≥310 minutes, ventilator dependence, and preoperative transfusions. Univariate analysis revealed a number of complications significantly associated with VTE occurrence, including unplanned intubation, ventilator use for >48 hours, stroke, sepsis, septic shock, pneumonia, urinary tract infection, and transfusions.

CONCLUSIONS

Risk factors of VTE and associated complications were identified. Understanding these risk factors provides physicians with further insight in managing this subgroup of patients in a personalized fashion in the perioperative period to minimize the incidence and morbidity of VTE.

The Rate of Venous Thromboembolism Before and After Spine Surgery as Determined with Indirect Multidetector CT

BACKGROUND

This prospective cohort study investigated the rate of venous thromboembolism (VTE) before and after spine surgery as determined with use of indirect multidetector computed tomography (MDCT).

METHODS

We performed a prospective study of 105 patients (36 women and 69 men ranging in age from 38 to 88 years) undergoing spine surgery at 2 institutions. Indirect MDCT was performed before and 3 days after surgery. Patients with a history of dialysis or drug allergy to contrast medium were excluded.

RESULTS

No patient had symptomatic VTE preoperatively or postoperatively. The preoperative and postoperative rates of asymptomatic VTE were 4.8% and 13.0%, respectively; the rates of asymptomatic pulmonary embolism were 2.9% and 8.0%, respectively; and the rates of asymptomatic deep venous thrombosis were 3.8% and 6.0%, respectively. Age, sex, height, weight, body mass index, operative time, volume of intraoperative blood loss, and specific comorbidities (diabetes, hypertension, cardiac disease, previous VTE, and previous anticoagulation treatment) were not found to be risk factors.

CONCLUSIONS

Our findings demonstrated a low rate of preoperative VTE but a high rate of postoperative VTE in association with spine surgery. Surgeons need to be aware of the risk of VTE in patients undergoing spine surgery. MDCT is an effective and convenient technology for the early detection of VTE in such patients.

LEVEL OF EVIDENCE

Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Severe Leg Pain Following Spinal Cord Stimulator Implantation - A Case Report

Following spinal cord stimulator (SCS) implantation, postoperative pain is commonly incisional or neuropathic from neurological damage. Occasionally, this new pain may mimic symptoms caused by preexisting pathology. This article presents a case of immediate, severe, postoperative leg pain secondary to a lower extremity deep vein thrombosis (DVT) and subsequent pulmonary embolism after percutaneous SCS implantation for failed back syndrome. The risk factors of DVT after spine surgery and perioperative prophylaxis are further discussed with a brief literature review. LEVEL OF EVIDENCE: V.

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.

Short-term outcomes following posterior cervical fusion among octogenarians with cervical spondylotic myelopathy: a NSQIP database analysis

BACKGROUND CONTEXT

Degenerative changes in the cervical spine occur in an age-dependent manner. As the US population continues to age, the incidence of age-dependent, multilevel, degenerative cervical pathologies is expected to increase. Similarly, the average age of patients with cervical spondylotic myelopathy (CSM) will likely trend upward. Posterior cervical fusion (PCF) is often the treatment modality of choice in the management of multilevel cervical spine disease. Although outcomes following anterior cervical fusion for degenerative disease have been studied among older patients (aged 80 years and older), it is unknown if these results extend to octogenarian patients undergoing PCF for the surgical management of CSM.

PURPOSE

The present study aimed to quantify surgical outcomes following PCF for the treatment of CSM among the octogenarian patient population compared with patients younger than 80 years old.

STUDY DESIGN/SETTING

This was a retrospective study that used the National Surgical Quality Improvement Program (NSQIP).

PATIENT SAMPLE

The sample included patients aged 60-89 who had CSM and who underwent PCF from 2012 to 2014.

OUTCOME MEASURES

The outcome measures were multimorbidity, prolonged length of stay (LOS), discharge disposition (to home or skilled nursing/rehabilitation facility), 30-day all-cause readmission, and 30-day reoperation.

METHODS

The NSQIP database was queried for patients with CSM (International Classification of Disease, Ninth Revision, Clinical Modification code 721.1) aged 60-89 who underwent PCF (Current Procedural Terminology code 22600) from 2012 to 2014. Cohorts were defined by age group (60-69, 70-79, 80-89). Data were collected on gender, race, elective or emergent status, inpatientor outpatient status, where patients were admitted from (home vs. skilled nursing facility), American Society of Anesthesiologists class, comorbidities, and single- or multilevel fusion. After controllingfor these variables, logistic regression analysis was used to compare outcome measures in the different age groups.

RESULTS

A total of 819 patients with CSM who underwent PCF (416 aged 60-69, 320 aged 70-79, and 83 aged 80-89) were identified from 2012 to 2014. Of the PCF procedures, 79.7% were multilevel. There were no significant differences in the odds of multimorbidity, prolonged LOS, readmission, or reoperation when comparing octogenarian patients with CSM with patients aged 60-69 or 70-79. Patients aged 60-69 and 70-79 were significantly more likely to be discharged to home than patients over 80 (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.8-10.4, p<.0001, and OR 2.7, 95% CI 1.1-6.4, p=.0005, respectively).

CONCLUSIONS

Compared with patients aged 60-69 and 70-79, octogenarian patients with CSM were significantly more likely to be discharged to a location other than home following PCF. After controlling for patient comorbidities and demographics, 80- to 89-year-old patients with CSM who underwent PCF did not differ in other outcomes when compared with the other age cohorts. These results can improve preoperative risk counseling and surgical decision-making.

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.

Prolonged operative duration is associated with complications: a systematic review and meta-analysis

BACKGROUND

The aim of this study was to systematically synthesize the large volume of literature reporting on the association between operative duration and complications across various surgical specialties and procedure types.

METHODS

An electronic search of PubMed, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews from January 2005 to January 2015 was conducted. Sixty-six observational studies met the inclusion criteria.

RESULTS

Pooled analyses showed that the likelihood of complications increased significantly with prolonged operative duration, approximately doubling with operative time thresholds exceeding 2 or more hours. Meta-analyses also demonstrated a 14% increase in the likelihood of complications for every 30 min of additional operating time.

CONCLUSIONS

Prolonged operative time is associated with an increase in the risk of complications. Given the adverse consequences of complications, decreased operative times should be a universal goal for surgeons, hospitals, and policy-makers. Future study is recommended on the evaluation of interventions targeted to reducing operating time.

Comparison of apixaban and rivaroxaban for anticoagulant effect after lumbar spine surgery: a single-center report

Aim

To compare efficacy and safety of anticoagulants apixaban and rivaroxaban after lumbar spine surgery retrospectively.

Methods

In this study comprising 480 patients, lower-limb swelling, deep venous thrombosis, pulmonary embolism, blood loss, ecchymosis and D-dimer changes were observed.

Results

The changes in perimeter of the legs were tested, and significant differences were noted 10 cm above the patella, but no significant differences 10 cm below the patella. Twelve thrombotic events occurred in the apixaban group and nine in rivaroxaban group. No significant difference in the incidences of thromboembolic events (p = 1.00). Compared with rivaroxaban, there was significantly less bleeding in the apixaban group (p = 0.03).

Conclusion

Apixaban and rivaroxaban were equally effective anticoagulation therapies that exhibited similar preventive effects against postoperative venous thromboembolism after lumbar spine surgery.

Performance Indicators in Spine Surgery

STUDY DESIGN

Systematic review.

OBJECTIVE

To elucidate how performance indicators are currently used in spine surgery.

SUMMARY OF BACKGROUND DATA

The Patient Protection and Affordable Care Act has given significant traction to the idea that healthcare must provide value to the patient through the introduction of hospital value-based purchasing. The key to implementing this new paradigm is to measure this value notably through performance indicators.

METHODS

MEDLINE, CINAHL Plus, EMBASE, and Google Scholar were searched for studies reporting the use of performance indicators specific to spine surgery. We followed the Prisma-P methodology for a systematic review for entries from January 1980 to July 2016. All full text articles were then reviewed to identify any measure of performance published within the article. This measure was then examined as per the three criteria of established standard, exclusion/risk adjustment, and benchmarking to determine if it constituted a performance indicator.

RESULTS

The initial search yielded 85 results among which two relevant studies were identified. The extended search gave a total of 865 citations across databases among which 15 new articles were identified. The grey literature search provided five additional reports which in turn led to six additional articles. A total of 27 full text articles and reports were retrieved and reviewed. We were unable to identify performance indicators. The articles presenting a measure of performance were organized based on how many criteria they lacked. We further examined the next steps to be taken to craft the first performance indicator in spine surgery.

CONCLUSION

The science of performance measurement applied to spine surgery is still in its infancy. Current outcome metrics used in clinical settings require refinement to become performance indicators. Current registry work is providing the necessary foundation, but requires benchmarking to truly measure performance.

LEVEL OF EVIDENCE

1.