The prophylactic use of inferior vena cava filters in patients undergoing high-risk spinal surgery

Utility and Clinical Outcomes of Perioperative Inferior Vena Cava Filter Prophylaxis in Spine Surgery Patients

STUDY DESIGN

Single-center retrospective chart review study.

OBJECTIVE

This study aimed to assess the clinical outcomes of prophylactic inferior vena cava (IVC) filter use for pulmonary embolism (PE) prevention in spine surgery patients.

SUMMARY OF BACKGROUND DATA

IVC filters can serve an important prophylactic role in preventing PE, though research involving spine surgery patients is sparse.

MATERIALS AND METHODS

This Institutional Review Board-approved single-center retrospective study assessed the characteristics and outcomes of patients who underwent spine surgery and received perioperative IVC filters for PE prophylaxis from January 2007 until December 2021. Clinical outcomes centered primarily on the occurrence of venous thromboembolism (VTE) as well as complications related to filter placement and retrieval. Thrombi that may have been entrapped by the filters were recorded incidentally on computed tomography or during the filter retrieval procedure.

RESULTS

This cohort included 380 spine surgery patients (female 51%/male 49%; median age, 61) who had received perioperative prophylactic IVC filters. The mean dwell time was 6.7 months (1-39 mo), with an overall 62% retrieval rate. Retrievals were further categorized by retrieval complexity, with 92% classified as routine and 8% as involving advanced removal techniques, while complications involved 1% (four retrievals) and were all minor. Regarding VTE event occurrence, deep vein thrombi (DVT) were experienced by 11% of patients in the postplacement period, with 1% (n=4) experiencing a PE. There were 11 incidences of thrombi that were found within or near the filters (2.9%). A multivariate analysis further assessed patient characteristics that correlated with the occurrence of PE, DVT, entrapped filter thrombi, advanced technique filter removal, and removal complications.

CONCLUSIONS

IVC filters in this high-risk spine surgery cohort achieved a relatively low rate of DVT and PE as well as a low complication rate, whereas several patient characteristics were identified that correlated with VTE events and filter retrieval outcomes.

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

Background

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

Methods

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

Results

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

Conclusions

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

Do Prophylactic Inferior Vena Cava Filters Affect the Rates of Venous Thromboembolism and Pulmonary Embolism in Patients Undergoing Major Spine Surgery?

STUDY DESIGN

Retrospective Analysis.

BACKGROUND

Venous thromboembolism (VTE) represents a significant cause of morbidity and mortality in major spine surgery. Placement of prophylactic inferior vena cava filters (IVCF) in patients undergoing major spine surgery was previously adopted at our institution. This study reports our experience and compares VTE rates between patients with and without preoperative IVCF placement.

METHODS

A Retrospective comparative study was conducted on adult patients who underwent IVCF placement and those who did not prior to their spinal fusion procedure, between 2013 and 2016. Thoracolumbar fusions (anterior and/or posterior) of 7 or more levels, spinal osteotomies, and a minimum of a 3-month follow-up were included. Traumatic, oncologic, and cervical pathology were excluded. Primary outcomes measured included the incidence of overall VTE (DVT/PE), death, IVCF related complications, and IVCF retrieval.

RESULTS

386 patients who underwent major spine surgery, 258 met the eligibility criteria. Of those patients, 105 patients (40.7%) had prophylactic IVCF placement. All patients had postoperative SCDs and chemoprophylaxis. The presence of an IVCF was associated with an increased rate of overall VTE (14.3% vs 6.5%, P ≤ .05) and DVT episodes (8.6% vs 2.6%, P = .04). The rate of PE for the IVCF group and non-IVCF group was 8.6% and 4.6%, respectively, which was not statistically significant (P = .32). The all-cause mortality rate overall of 2.3% was statistically similar between both groups (P = 1.0). The IVCF group had higher rates of hematoma/seroma vs the non-IVCF group (12.4% vs 3.9%, P ≤ .05). 99 IVCFs were retrievable designs, and 85% were successfully retrieved. Overall IVCF-related complication rate was 11%.

CONCLUSIONS

No statistical difference in PE or mortality rates existed between the IVCF and the control group. Patients with IVCF placement experienced approximately twice the rate of VTE and three times the rate of DVT compared to those without IVCF. The IVCF-related complication rate was 11%. Based on the results of this study, the authors recommend against the routine use of prophylactic IVCFs in adults undergoing major spine surgery.

LEVEL OF EVIDENCE

III.

Prevalence of Asymptomatic Deep Vein Thrombosis in Preoperative State of Spine Surgeries

BACKGROUND

Deep venous thrombosis (DVT) is considered the most common cause of preventable death among hospitalized patients. A few studies have investigated the risk of venous thromboembolic events in patients undergoing elective spine surgery and reported varying incidences. We aim to assess the incidence of preoperative lower limb DVT in patients with lumbar degenerative disease undergoing elective surgery.

METHODS

This is a retrospective review of prospectively collected data on adult patients with lumbar degenerative spine diseases (lumbar stenosis [LST], lumbar spondylolisthesis [SPL], or lumbar disc herniation) who were scheduled for operative management. Each patient underwent a preoperative lower limb venous Duplex (LLVD). Incidence of DVT, risk factors, and clinical course of patients were reported.

RESULTS

Forty-nine patients (32 females; 65%) were included. All patients were diagnosed clinically and radiologically with lumbar degenerative diseases; LST (44.9%), SPL (36.7%), and lumbar disc herniation (18.4%), requiring surgical management. Three patients (6.1%) were found to have positive DVT studies, leading to the cancellation or rescheduling of their procedures (P < 0.01). These included 1 patient with LST (P = 0.045) and 2 patients with SPL (P = 0.006). Among patients with LST and SPL, higher disability (modified Rankin scale ≥3) was significantly associated with positive LLVD (P = 0.035).

CONCLUSION

Patients with LST or SPL with higher preoperative disability scores were at higher risk to have preoperative DVT. Further research is needed to evaluate the feasibility and value of preoperative LLVD to detect DVT in patients planned for lumbar degenerative surgery.

The application of inferior vena cava filters in orthopaedics and current research advances

Deep vein thrombosis is a common clinical peripheral vascular disease that occurs frequently in orthopaedic patients and may lead to pulmonary embolism (PE) if the thrombus is dislodged. pulmonary embolism can be prevented by placing an inferior vena cava filter (IVCF) to intercept the dislodged thrombus. Thus, IVCFs play an important role in orthopaedics. However, the occurrence of complications after inferior vena cava filter placement, particularly recurrent thromboembolism, makes it necessary to carefully assess the risk-benefit of filter placement. There is no accepted statement as to whether IVCF should be placed in orthopaedic patients. Based on the problems currently displayed in the use of IVCFs, an ideal IVCF is proposed that does not affect the vessel wall and haemodynamics and intercepts thrombi well. The biodegradable filters that currently exist come close to the description of an ideal filter that can reduce the occurrence of various complications. Currently available biodegradable IVCFs consist of various organic polymeric materials. Biodegradable metals have shown good performance in making biodegradable IVCFs. However, among the available experimental studies on degradable filters, there are no experimental studies on filters made of degradable metals. This article reviews the use of IVCFs in orthopaedics, the current status of filters and the progress of research into biodegradable vena cava filters and suggests possible future developments based on the published literature by an electronic search of PubMed and Medline databases for articles related to IVCFs searchable by October 2022 and a manual search for citations to relevant studies.

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.

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.

Risk factors of postoperative deep vein thrombosis (DVT) under low molecular weight heparin (LMWH) prophylaxis in patients with thoracolumbar fractures caused by high-energy injuries

To determine the incidence of DVT and to evaluate the risk factors of DVT under LMWH prophylaxis in patients with thoracolumbar fractures caused by high‑energy injuries postoperatively. A total of 534 patients from January 2016 to November 2019 were included in this retrospective study. Medical record data, including demographic data, perioperative variables, and laboratory results, were collected. LMWH prophylaxis was used for DVT in all the patients. The incidence and risk factors of DVT after surgery were identified by logistic regression analysis and receiver operating characteristic (ROC) curve analysis. The overall incidence of postoperative DVT was 18.91% (101/534). Three patients (0.56%) had proximal DVT and ninety-eight (18.35%) patients had distal DVT. The incidence of postoperative DVT in patients with thoracic fractures was 26.80% and 15.50% with lumbar fractures. The multivariate analysis showed that six risk factors increased the incidence of postoperative DVT, including advanced age, decreased lower extremity motor, blood transfusion, duration of bed rests, fibrinogen (FIB), and D-dimer. The ROC analysis indicated that the diagnostic value of D-dimer was highest whose area under the ROC curves (AUC) value was 0.754. Despite LMWH prophylaxis, the risk of postoperative DVT is still very high, especially in thoracic fracture. Advanced age, decreased lower extremity motor, blood transfusion, duration of bed rests, FIB, and D-dimer are risk factors for DVT. Moreover, the diagnostic value of D-dimer is the highest among these factors.

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.

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.

Perioperative outcomes associated with thoracolumbar 3-column osteotomies for adult spinal deformity patients with rheumatoid arthritis

OBJECTIVE

Spinal deformity causing spinal imbalance is directly correlated to pain and disability. Prior studies suggest adult spinal deformity (ASD) patients with rheumatoid arthritis (RA) have more complex deformities and are at higher risk for complications. In this study the authors compared outcomes of ASD patients with RA following thoracolumbar 3-column osteotomies to outcomes of a matched control cohort.

METHODS

All patients with RA who underwent 3-column osteotomy for thoracolumbar deformity correction performed by the senior author from 2006 to 2016 were identified retrospectively. A cohort of patients without RA who underwent 3-column osteotomies for deformity correction was matched based on multiple clinical factors. Data regarding demographics and surgical approach, along with endpoints including perioperative outcomes, reoperations, and incidence of proximal junctional kyphosis (PJK) were reviewed. Univariate analyses were used to compare patients with RA to matched controls.

RESULTS

Eighteen ASD patients with RA were identified, and a matched cohort of 217 patients was generated. With regard to patients with RA, 11.1% were male and the mean age was 68.1 years. Vertebral column resection (VCR) was performed in 22.2% and pedicle subtraction osteotomy (PSO) in 77.8% of patients. Mean case length was 324.4 minutes and estimated blood loss (EBL) was 2053.6 ml. Complications were observed in 38.9% of patients with RA and 29.0% of patients without RA (p = 0.380), with a trend toward increased medical complications (38.9% vs 21.2%, p = 0.084). Patients with RA had a significantly higher incidence of deep vein thrombosis (DVT)/pulmonary embolism (PE) (11.1% vs 1.8%, p = 0.017) and wound infections (16.7% vs 5.1%, p = 0.046). PJK occurred in 16.7% of patients with RA, and 33.3% of RA patients underwent reoperation. Incidence rates of PJK and reoperation in matched controls were 12.9% and 25.3%, respectively (p = 0.373, p = 0.458). At follow-up, mean sagittal vertical axis (SVA) was 6.1 cm in patients with RA and 4.5 cm in matched controls (p = 0.206).

CONCLUSIONS

Findings from this study suggest that RA patients experience a higher incidence of medical complications, specifically DVT/PE. Preoperative lower-extremity ultrasounds, inferior vena cava (IVC) filter placement, and/or early initiation of DVT prophylaxis in RA patients may be indicated. Perioperative complications, morbidity, and long-term outcomes are otherwise similar to non-RA patients.

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.

Adverse Outcomes and Prediction of Cardiopulmonary Complications in Elective Spine Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of this study was to report incidence of cardiopulmonary complications in elective spine surgery, demographic and surgical predictors, and outcomes. Understanding the risks and predictors of these sentinel events is important for risk evaluation, allocation of hospital resources, and counseling patients.

METHODS

A retrospective review of the National Surgical Quality Improvement Program (NSQIP) was performed on 60 964 patients undergoing elective spine surgery (any region; laminectomy, arthrodesis, discectomy, or laminoplasty) between 2011 and 2013. Incidence of myocardial infarction, cardiac arrest, unplanned reintubation, on ventilator >48 hours, perioperative pneumonia, and pulmonary embolism was measured. Demographic and surgical predictors of cardiopulmonary complications and associated outcomes (length of stay, discharge disposition, and mortality) were measured using binary logistic regression controlling for confounders.

RESULTS

Incidence rates per 1000 elective spine patients were 2.1 myocardial infarctions, 1.3 cardiac arrests, 4.3 unplanned intubations, 3.5 on ventilator >48 hours, 6.1 perioperative pneumonia, and 3.7 pulmonary embolisms. In analysis of procedure, diagnosis, and approach risk factors, thoracic cavity (odds ratio = 2.47; confidence interval = 1.95-3.12), scoliosis diagnosis, and combined approach (odds ratio = 1.51; confidence interval = 1.15-1.96) independently added the most risk for cardiopulmonary complication. Cardiac arrest had the highest mortality rate (34.57%). Being on ventilator greater than 48 hours resulted in the greatest increase to length of stay (17.58 days).

CONCLUSIONS

Expected risk factors seen in the Revised Cardiac Risk Index were applicable in the context of spine surgery. Surgical planning should take into account patients who are at higher risk for cardiopulmonary complications and the implications they have on patient outcome.

Are too many inferior vena cava filters used? Controversial evidences in different clinical settings: a narrative review

The use of inferior vena cava filters to prevent pulmonary embolism is increasing mainly because of indications that appear to be unclearly codified and recommended. The evidence supporting this approach is often heterogeneous, and mainly based on observational studies and consensus opinions, while the insertion of an IVC filter exposes patients to the risk of complications and increases health care costs. Thus, several proposed indications for an IVC filter placement remain controversial. We attempt to review the proof on the efficacy and safety of IVC filters in several "special" clinical settings, and assess the robustness of the available evidence for any specific indication to place an IVC filter.

Predictors of Readmissions and Reoperations Related to Venous Thromboembolic Events After Spine Surgery: A Single-Institution Experience with 6869 Patients

BACKGROUND

Readmission and reoperation are used as hospital and surgeon quality metrics. Venous thromboembolic (VTE) events, including deep vein thrombosis and pulmonary embolism (PE), are a major cause of readmission, morbidity, and mortality after spine surgery. Specific procedural, perioperative, and patient characteristics may be associated with these outcomes.

METHODS

We retrospectively examined records from 6869 consecutive spine surgeries at our institution. We collected data on patient demographics, surgery, hospital course, and 30-day rates of VTE, readmission, reoperation, and epidural hematoma. Stepwise multivariable logistic regression was used to identify independent predictors of each outcome.

RESULTS

Factors associated with VTE within 30 days of surgery include a history of VTE (odds ratio [OR] 3.92 [confidence interval 1.83-8.36], P < 0.001), estimated blood loss (EBL; OR 1.017 [1.005-1.029], P = 0.004), fracture (OR 5.42 [2.09-14.05], P = 0.001), history of PE (OR 4.04 [1.22-13.42], P = 0.023), and transfusion (OR 2.26 [1.07-4.77], P = 0.033). Factors associated with readmission were a history of PE (OR 3.27 [1.07-9.97], P = 0.038), PE (OR 8.07 [2.26-28.8], P = 0.001), transfusion (OR 2.54 [1.55-4.17], P < 0.001), comorbid disease burden (OR 1.35 [1.01-1.80], P = 0.041), and tumor surgery (OR 2.84 [1.32-6.10], P = 0.007). Factors associated with reoperation were EBL (OR 1.024 [1.006-1.042], P = 0.008), transfusion (OR 3.86 [1.38-10.79], P = 0.01), and PE (OR 6.05 [1.03-35.62], P = 0.046). Transfusion was associated with epidural hematoma within 30 days (OR 7.38 [1.37-39.83], P = 0.02).

CONCLUSIONS

Transfusion and EBL are associated with numerous negative outcomes. Transfusion is an independent predictor of VTE, readmission, reoperation, and epidural hematoma requiring evacuation. Specific pathologies were associated with specific negative outcomes.

Incidence and risk factors for preoperative deep venous thrombosis in 314 consecutive patients undergoing surgery for spinal metastasis

OBJECTIVE The authors of this study aimed to identify the incidence of and risk factors for preoperative deep venous thrombosis (DVT) in patients undergoing surgical treatment for spinal metastases. METHODS Univariate analysis of patient age, sex, ethnicity, laboratory values, comorbidities, preoperative ambulatory status, histopathological classification, spinal level, and surgical details was performed. Factors significantly associated with DVT univariately were entered into a multivariate logistic regression model. RESULTS The authors identified 314 patients, of whom 232 (73.9%) were screened preoperatively for a DVT. Of those screened, 22 (9.48%) were diagnosed with a DVT. The screened patients were older (median 62 vs 55 years, p = 0.0008), but otherwise similar in baseline characteristics. Nonambulatory status, previous history of DVT, lower partial thromboplastin time, and lower hemoglobin level were statistically significant and independent factors associated with positive results of screening for a DVT. Results of screening were positive in only 6.4% of ambulatory patients in contrast to 24.4% of nonambulatory patients, yielding an odds ratio of 4.73 (95% CI 1.88-11.90). All of the patients who had positive screening results underwent preoperative placement of an inferior vena cava filter. CONCLUSIONS Patients requiring surgery for spinal metastases represent a population with unique risks for venous thromboembolism. This study showed a 9.48% incidence of DVT in patients screened preoperatively. The highest rates of preoperative DVT were identified in nonambulatory patients, who were found to have a 4-fold increase in the likelihood of harboring a DVT. Understanding the preoperative thrombotic status may provide an opportunity for early intervention and risk stratification in this critically ill population.

Robotic-Assisted Inferior Vena Cava Filter Retrieval

Although anticoagulation remains the mainstay of therapy for patients with venous thromboembolism, guidelines recommend the use of inferior vena cava (IVC) filters in those who fail anticoagulation or have contraindications to its use. Short-term use of filters has proven effective in reducing the rate of pulmonary embolism. However, their extended use is associated with a variety of complications such as thrombosis, filter migration, or caval perforation, thus making a case for timely filter retrieval. This is the case of a 68-year-old female with a history of chronic oral anticoagulation use for multiple deep venous thrombi (DVT) and pulmonary emboli (PE) who required cervical and thoracic spinal intervention for spondylosis and foramina stenosis. Given her increased risk of recurrent DVT and PE perioperatively, we elected to place a Cook Celect^™ IVC filter (Cook Medical, Bloomington, IN) after oral anticoagulation was stopped for the procedure. Her treatment course was prolonged due to wound-healing complications. We elected to use the Magellan Robotic Catheter System (Hansen Medical, Mountain View, CA) for filter retrieval when she presented 6 months later with caval perforation from the filter struts. With its ease of use, superior mechanical stability, and maneuverability, robot-assisted IVC filter retrieval may be a safer and more reliable substitute for traditional navigation techniques when presented with challenging filter retrievals.

Risk factors associated with venous thromboembolism in patients undergoing spine surgery

OBJECTIVE

Patients undergoing spinal surgery are at risk for developing venous thromboembolism (VTE). The authors sought to identify risk factors for VTE in these patients.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project database for the years 2006–2010 was reviewed for patients who had undergone spinal surgery according to their primary Current Procedural Terminology code(s). Clinical factors were analyzed to identify associations with VTE.

RESULTS

Patients who underwent spinal surgery (n = 22,434) were identified. The rate of VTE in the cohort was 1.1% (pulmonary embolism 0.4%; deep vein thrombosis 0.8%). Multivariate binary logistic regression analysis revealed 13 factors associated with VTE. Preoperative factors included dependent functional status, paraplegia, quadriplegia, disseminated cancer, inpatient status, hypertension, history of transient ischemic attack, sepsis, and African American race. Operative factors included surgery duration > 4 hours, emergency presentation, and American Society of Anesthesiologists Class III–V, whereas postoperative sepsis was the only significant postoperative factor. A risk score was developed based on the number of factors present in each patient. Patients with a score of ≥ 7 had a 100-fold increased risk of developing VTE over patients with a score of 0. The receiver-operating-characteristic curve of the risk score generated an area under the curve of 0.756 (95% CI 0.726–0.787).

CONCLUSIONS

A risk score based on race, preoperative comorbidities, and operative characteristics of patients undergoing spinal surgery predicts the postoperative VTE rate. Many of these risks can be identified before surgery. Future protocols should focus on VTE prevention in patients who are predisposed to it.

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.

Risk Factors for Venous Thromboembolism following Thoracolumbar Surgery: Analysis of 43,777 Patients from the American College of Surgeons National Surgical Quality Improvement Program 2005 to 2012

Study Design Retrospective clinical study of a prospectively collected, national database. Objective Determine the 30-day incidence, timing, and risk factors for venous thromboembolism (VTE) following thoracolumbar spine surgery. Methods The American College of Surgeons National Surgical Quality Improvement Program Participant Use File identified 43,777 patients who underwent thoracolumbar surgery from 2005 to 2012. Multiple patient characteristics were identified. The incidence and timing (in days) of deep vein thrombosis (DVT) and pulmonary embolus (PE) were determined. Multivariable regression analysis was performed to identify significant risk factors. Results Of the 43,777 patients identified as having had thoracolumbar surgery, 202 cases of PE (0.5%) and 311 cases of DVT (0.7%) were identified. VTE rates were highest in patients undergoing corpectomy, with a 1.7% PE rate and a 3.8% DVT rate. Independent risk factors for VTE included length of stay (LOS) ≥ 6 days (odds ratio [OR] 4.07), disseminated cancer (OR 1.77), white blood cell count > 12 (OR 1.76), paraplegia (OR 1.75), albumin < 3 (OR 1.73), American Society of Anesthesiologists class 4 or greater (OR 1.54), body mass index > 40 (OR 1.49), and operative time > 193 minutes (OR 1.43). LOS < 3 days was protective (OR 0.427). Conclusions We report an overall 30-day PE rate of 0.5% and DVT rate of 0.7% following thoracolumbar spine surgery. Patients undergoing corpectomy were at highest risk for VTE. Multiple VTE risk factors were identified. Further studies are needed to develop algorithms to stratify VTE risk and direct prophylaxis accordingly.

Preoperative deep vein thrombosis in patients with cervical spondylotic myelopathy scheduled for spinal surgery

INTRODUCTION

The prevalence of deep vein thrombosis (DVT) and its risk factors in patients with cervical spondylotic myelopathy (CSM) before spinal surgery are poorly understood. We investigated this association with a retrospective cross-sectional study.

PATIENTS CONCERNS

The study cohort consisted of all consecutive patients with CSM who were scheduled for spinal surgery at our institution from 2013 to 2015. DVT was defined as an intraluminal filling defect in a lower extremity vein identified by Doppler ultrasonography.

OUTCOMES

Of the 396 patients with CSM, 16 (4%) had DVT. Compared with patients without preoperative DVT, patients with preoperative DVT were older (62.75 ± 8.79 vs 53.03 ± 10.95 years, P = 0.001), had higher D-dimer concentrations (2.23 ± 4.15 vs 0.43 ± 0.90 mg/L, P = 0.04), had experienced longer duration of CSM (7.56 ± 7.08 vs 4.01 ± 6.37 months, P = 0.03), had lower Japanese Orthopaedic Association lower limb motor dysfunction scores (1.68 ± 1.25 vs 2.54 ± 0.91, P = 0.01), and had a history of ischemic cardiovascular events (33.3% vs 2.1%, P = 0.02). The area under the curve for the ability of D-dimer levels to predict DVT was 0.858 (95% confidence interval: 0.764-0.951; P < 0.0001). A D-dimer level of 0.54 mg/L detected DVT with a sensitivity and specificity of 87.5% and 83.2%, respectively. Abnormal D-dimer levels and ischemic cardiovascular events history were independent predictors of DVT.

CONCLUSION

Patients with CSM who were scheduled for surgery often presented with preoperative DVT. Preoperative vascular screening should be considered for patients with CSM, especially for those who are older, have had longer duration of CSM, have poor lower limb mobility, and have a heart disease history. Inferior vena cava filter insertion and anticoagulation treatments should be considered for CSM patients with preoperative DVT.

Thromboembolic Disease after Cervical Spine Surgery: A Review of 5,405 Surgical Procedures and Matched Cohort Analysis

STUDY DESIGN

Retrospective matched cohort analysis.

OBJECTIVE

The majority of the literature on venous thromboembolism (VTE) after spine surgery is limited to studies of thoracolumbar surgery. Less is known regarding the incidence of VTE and associated risk factors following cervical spine surgery.

METHODS

A total of 5,405 patients at our institution underwent cervical diskectomy, laminectomy, corpectomy, laminoplasty, or fusion between 1995 and 2012; 85 of the 5,405 patients (1.57%) suffered either a DVT (55) or pulmonary embolus (51) within 30 days postoperatively. The cases were matched 1:2 to controls based on age, sex, and date of surgery. Data regarding multiple perioperative factors, demographics, and comorbidities was collected.

RESULTS

Several risk factors were identified for VTE. Significant medical comorbidities included chronic venous insufficiency (odds ratio [OR] = 3.40), atrial fibrillation (OR = 2.69), obesity (OR = 2.67), and ischemic heart disease (OR = 2.18). Staged surgery (OR = 28.0), paralysis (OR = 19.0), combined approach (OR = 7.46), surgery for infection (OR = 18.5), surgery for trauma (OR = 11.1), comorbid traumatic injuries (OR > 10), oncologic procedures (OR = 5.2), use of iliac crest autograft (OR = 4.16), two or more surgical levels (OR = 3.48), blood loss > 300 mL (OR = 1.66), and length of stay 5 days or greater (OR = 3.47) were all found to be risk factors for VTE (p < 0.05) in univariate analysis. Multivariate analysis found staged surgery (OR = 35.7), paralysis (OR = 7.86), and nonelective surgery (OR = 6.29) to be independent risk factors for VTE.

CONCLUSIONS

Although the incidence of VTE following cervical spine surgery is low, we identified several risk factors that may be predictive. More aggressive approaches to prophylaxis and surveillance in certain patient populations may be warranted.

Perioperative complications associated with spine surgery in patients with established spinal cord injury

BACKGROUND CONTEXT

Only a small percentage of patients with spinal cord injury (SCI) require consideration for reconstructive surgery after their initial injury. For those who do, perioperative complications can be frequent and significant. There has been very little published literature examining treatment of these patients and essentially nothing to guide the surgeon in perioperative decision making and management.

PURPOSE

To identify some of the common challenges associated with surgery in this patient population and review the literature to highlight the perioperative concerns in patients with chronic SCI.

STUDY DESIGN

Review article.

METHODS

A primary PubMed literature search was performed and reviewed for patients with chronic SCI with emphasis on the complications and difficulties encountered during surgical treatment of patients with chronic SCI.

RESULTS

For those who do proceed with surgery in this patient population, preoperative nutrition, bone density, and skin should be evaluated and optimized. Preoperative inferior vena cava filters should be considered. The integrity of the reconstruction will be extensively challenged. In addition, augmented fixation and bracing should be contemplated.

CONCLUSIONS

Patients with chronic SCI who require spinal reconstruction provide many unique challenges. Indications for surgery must be strong as perioperative complications can be frequent and long-term outcomes unpredictable. Close monitoring for postoperative complications is essential.

Quality and Safety in Orthopaedics: Learning and Teaching at the Same Time: AOA Critical Issues

Increasing attention has been placed on providing higher quality and safer patient care. This requires the development of a new set of competencies to better understand and navigate the system and lead the orthopaedic team. While still trying to learn and develop these competencies, the academic orthopaedist is also expected to model and teach them.The orthopaedic surgeon must understand what is being measured and why, both for purposes of providing better care and to eliminate unnecessary expense in the system. Metrics currently include hospital-acquired conditions, "never events," and thirty-day readmission rates. More will undoubtedly follow.Although commitment and excellence at the individual level are essential, the orthopaedist must think at the systems level to provide the highest value of care. A work culture characterized by respect and trust is essential to improved communication, teamwork, and confidential peer review. An increasing number of resources, both in print and electronic format, are available for us to understand what we can do now to improve quality and safety.Resident education in quality and safety is a fundamental component of the systems-based practice competency, the Next Accreditation System, and the Clinical Learning Environment Review. This needs to be longitudinally integrated into the curriculum and applied parallel to the development of resident knowledge and skill, and will be best learned if resident learning is experiential and taught within a genuine culture of quality and safety.

Prophylactic inferior vena cava filter placement prior to lumbar surgery in morbidly obese patients: Two-case study and literature review

Background:

Preoperative “prophylactic” placement of inferior vena cava (IVC) filters in morbidly obese patients (e.g., body mass index [BMI] >40 or BMI over 35 with hypertension/diabetes) undergoing multilevel decompressive lumbar laminectomies may reduce the risk of postoperative pulmonary embolism (PE), and death.

Methods:

Two patients, ages 69 and 68, with morbid obesity (BMI's of 40.4 and 37.5 both with hypertension and diabetes), received prophylactic IVC filters prior to L1–S1 laminectomies. Intraoperatively and postoperatively, both received alternating compression stocking prophylaxis, and received subcutaneous heparin 5000 U q12 h 48 h after surgery until discharge; none developed deep venous thrombosis (DVT) or PE, and both filters were uneventfully removed within 3 postoperative months.

Results:

The spinal surgical literature largely supports the placement of IVC filters for major risk factors; obesity (BMI >40), a history of DVT/PE, cancer, fusions, hypercoagulation syndromes, pulmonary/circulatory disorders, preoperative/postoperative immobility, staged procedures (five spinal levels), combined anterior-posterior surgery, iliocaval manipulation, age >80, and prolonged surgery (e.g., >261 min vs. >8 h). Although the safety and efficacy of prophylactic IVC filters for spine surgery in patients with morbidly obesity are well substantiated, those for bariatric patients are less clear.

Conclusions:

Prophylactic IVC filters were successfully placed/retrieved in 2 morbidly obese patients, ages 68 and 69, undergoing L1–S1 lumbar decompressions. Although the spine surgery literature documents the safety/efficacy of prophylactic IVC filters in patients with morbid obesity, the bariatric literature still has major concerns.

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.

Decreased incidence of venous thromboembolism after spine surgery with early multimodal prophylaxis

Object

Venous thromboembolism (VTE) represents a significant complication after spine surgery, with reported rates as high as 2%–4%. Published institutional practices for VTE prophylaxis are highly variable. In 2008, the authors implemented a departmental protocol for early VTE prophylaxis consisting of combined compressive devices and subcutaneous heparin initiated either preoperatively or on the same day of surgery. In this study, the authors compared the incidence of VTE in spine surgery patients before and after implementing this protocol.

Methods

An institutional review board–approved retrospective review of outcomes in patients undergoing spine surgery 2 years before protocol implementation (representing the preprotocol group) and of outcomes in patients treated 2 years thereafter (the postprotocol group) was conducted. Inclusion criteria were that patients were 18 years or older and had been admitted for 1 or more days. Before 2008 (preprotocol), VTE prophylaxis was variable and provider dependent without any uniform protocol. Since 2008 (postprotocol), a new VTE-prophylaxis protocol was administered, starting either preoperatively or on the same day of surgery and continuing throughout hospitalization. The new protocol consisted of 5000 U heparin administered subcutaneously 3 times daily, except in patients older than 75 years or weighing less than 50 kg, who received this dose twice daily. All patients also received sequential compression devices (SCDs). The incidence of VTE in the 2 protocol phases was identified by codes of the International Classification of Diseases, Ninth Revision (ICD-9) codes for deep vein thrombosis (DVT) and pulmonary embolus (PE). Bleeding complications arising from anticoagulation treatments were evaluated by the Current Procedural Terminology (CPT) code for postoperative epidural hematoma (EDH) requiring evacuation.

Results

In total, 941 patients in the preprotocol group met the inclusion criteria: 25 had DVT (2.7%), 6 had PE (0.6%), and 6 had postoperative EDH (0.6%). In the postprotocol group, 992 patients met the criteria: 10 had DVT (1.0%), 5 had PE (0.5%), and 4 had postoperative EDH (0.4%). This reduction in DVT after the protocol's implementation was statistically significant (p = 0.009). Despite early aggressive prophylaxis, the incidence of postoperative EDH did not increase and compared favorably to the published literature.

Conclusions

At a high-volume tertiary center, an aggressive protocol for early VTE prophylaxis after spine surgery decreases VTE incidence without increasing morbidity.

Outcomes in neurosurgical patients who develop venous thromboembolism: a review of the RIETE registry

OBJECTIVES

Registro Informatizado de Enfermedad TromboEmbólica (RIETE) database was used to investigate whether neurosurgical patients with venous thromboembolism (VTE) were more likely to die of bleeding or VTE and the influence of anticoagulation on these outcomes.

METHODS

Clinical characteristics, treatment details, and 3-month outcomes were assessed in those who developed VTE after neurosurgery.

RESULTS

Of 40 663 patients enrolled, 392 (0.96%) had VTE in less than 60 days after neurosurgery. Most patients in the cohort (89%) received initial therapy with low-molecular-weight heparin, (33% received subtherapeutic doses). In the first week, 10 (2.6%) patients died (8 with pulmonary embolism [PE], no bleeding deaths; P = .005). After the first week, 20 (5.1%) patients died (2 with fatal bleeding, none from PE). Overall, this cohort was more likely to develop a fatal PE than a fatal bleed (8 vs 2 deaths, P = .058).

CONCLUSIONS

Neurosurgical patients developing VTE were more likely to die from PE than from bleeding in the first week, despite anticoagulation.

Prevalence and countermeasures for venous thromboembolic diseases associated with spinal surgery: a follow-up study of an institutional protocol in 209 patients

STUDY DESIGN

A prospective study of 209 patients undergoing spinal surgery.

OBJECTIVE

To determine the incidence of venous thromboembolic diseases, including deep venous thrombosis (DVT) and pulmonary embolism (PE), and to evaluate the effectiveness of an institutional protocol for venous thromboembolic diseases during the spinal surgery perioperative period.

SUMMARY OF BACKGROUND DATA

Although patients undergoing spinal surgery are at risk of venous thromboembolism (VTE), there are no universally accepted guidelines for VTE prophylaxis.

METHODS

Between December 2006 and January 2011, 209 patients undergoing spinal surgery (121 males, 88 females; average age: 64 yr), who also had ultrasonographic assessments of both legs before and after surgery, were prospectively assessed. A pneumatic sequential compression device and standard compression stockings were used for primary VTE prophylaxis. In Mie University Hospital protocol, pharmacological agents were not used for VTE prophylaxis after surgery. However, when a distal type DVT was found preoperatively, an anticoagulant medication was administered until 6 hours prior to surgery. After detection of DVTs, weekly ultrasonography assessed the DVT.

RESULTS

Twenty-three patients (11.0%) showed VTE in the spinal surgery perioperative period. Nine patients (4.3%) had VTE (PE with proximal DVT, 1 [0.5%]; distal DVT, 8 [3.8%]) before surgery. In the one case of asymptomatic PE with proximal DVT, an inferior vena cava filter was placed before surgery. Fourteen patients (6.7%) developed new-onset VTE (PE with proximal DVT, 2 [1.0%]; distal DVT, 12 [5.9%]) after spinal surgery. New-onset PE with proximal DVT occurred in 2 patients after surgery. Follow-up ultrasonographic assessment showed that the DVT disappeared completely in 85% (17/20) of patients with a distal type DVT during the perioperative period.

CONCLUSION

DVT assessment using ultrasonography is important for proper management of VTE during the perioperative period of spinal surgery, especially for high-risk patients, such as those with advanced age or neurological deficit. The institutional protocol for VTE using pneumatic sequential compression device and compression stockings is effective, although the administration of chemoprophylaxis should be considered for high-risk patients, such as those with spinal tumors and spinal trauma.

Fatal pulmonary embolism following spinal surgery in a patient with permanent inferior vena cava filter placement

It has been proven that the use of an inferior vena cava filter (IVCF) is effective in decreasing the incidence of pulmonary embolism (PE) in high-risk spinal surgery patients. A case of fatal PE after spinal surgery in a 78-year-old woman who had a history of pulmonary hypertension due to peripheral PE treated with a permanent IVCF and anticoagulant therapy for 3 years is reported. The patient had experienced an episode of recurrent PE during the withdrawal of anticoagulants, but she had uneventfully undergone two orthopedic surgeries with a preoperative unfractionated heparin infusion instead of oral warfarin. Three months after the second operation, she underwent posterior lumbar spinal fusion. The following morning, she suddenly complained of chest discomfort and dyspnea with SpO(2) 78 %. An electrocardiogram showed a right bundle branch block. Then, 30 min later, she suddenly lost consciousness, and her carotid pulse was not palpable. The patient died 2 h and 30 min after onset. Acute PE probably occurred because of a massive thrombus above the IVCF. This case suggests that the efficacy of long- term use of a permanent IVCF is limited in cases when anticoagulants must be withdrawn, such as for orthopedic surgery.

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

STUDY DESIGN

Retrospective review.

OBJECTIVE

To assess the safety and efficacy of prophylactic low-molecular-weight heparin (LMWH) started 24 to 36 hours after degenerative spine surgery.

SUMMARY OF BACKGROUND DATA

Venous thromboembolism (VTE) is a significant postoperative complication best averted with dual mechanical/pharmacological prophylaxis. Pharmacological prophylaxis is widely used in patients with spinal cord injury, but there is no consensus on its role in degenerative spine surgery, particularly after laminectomy with the concurrent risk of epidural hematoma. The literature suggests a small but potentially devastating hemorrhage risk when LMWH is started within 24 hours of spine surgery. An intermediate strategy is delayed LMWH initiation to minimize hemorrhage risk and retain benefits of dual prophylaxis.

METHODS

Operative reports of the senior author were retrospectively reviewed for all cases of cervical and lumbar laminectomy from 2007 to 2011. Single-level decompressions without fusion and all nondegenerative cases were excluded. Baseline and operative details were recorded. Mechanical prophylaxis was used throughout admission, and prophylactic LMWH was started postoperative day 1 at 10 PM. All cases of postoperative hemorrhage (epidural hematoma, superficial hematoma, persistent wound drainage), deep venous thrombosis, and pulmonary embolism were noted.

RESULTS

A total of 367 patients underwent multilevel laminectomy or laminectomy and fusion for degenerative disease. VTE risk factors (age >60 yr, smoking, obesity) were common. No patients receiving LMWH 24 to 36 hours after surgery developed postoperative hemorrhage (95% confidence interval: 0-0.8%). Nearly half of the study population underwent lower extremity ultrasonography or chest computed tomography, and acute VTE was diagnosed in 14 patients (3.8%; 95% confidence interval: 2.1-6.3).

CONCLUSION

LMWH prophylaxis seems to carry a very low hemorrhage risk when started 24 to 36 hours after spine surgery. Larger, prospective studies are needed to assess the safety of early delayed LMWH administration more definitively. Even with aggressive prophylaxis, patients undergoing fusion or multilevel laminectomy for degenerative disease are at significant risk for VTE.

Inferior vena cava filters for primary prophylaxis: when are they indicated?

Over the past several years there has been a rapid increase in the number of inferior vena cava (IVC) filters placed for primary thromboprophylaxis. Increased use has occurred in settings where other methods of thromboprophylaxis are viewed to be inadequate, technically challenging, or that place patients at an unacceptably high bleeding risk. These clinical services include trauma, bariatric surgery, neurosurgery, cancer, intensive care unit populations, and patients with a relative contraindication to anticoagulation. We review the studies to date addressing filter placement for these indications. Although preliminary data are promising, the patient populations most likely to benefit from prophylactic IVC filter placement have not been well defined, and randomized studies demonstrating efficacy have not been conducted. Moving forward, it will be critical to accomplish these two tasks if IVC filters are to continue to have a role in primary thromboprophylaxis.

Comprehensive assessment of prophylactic preoperative inferior vena cava filters for major spinal reconstruction in adults

STUDY DESIGN

A retrospective data analysis.

OBJECTIVE

To report a comprehensive assessment of preoperative prophylactic inferior vena cava (IVC) filter placement in spine surgery.

SUMMARY OF BACKGROUND DATA

Venous thromboembolism (VTE) is a serious complication after major spinal reconstructive surgery in adults. Specifically, pulmonary embolism (PE) can result in significant morbidity and mortality, and it has been reported in up to 13% of patients. Prophylactic IVC filter placement was initiated for all "high-risk" spinal surgery patients after a pilot study demonstrated decreased VTE-related morbidity and mortality.

METHODS

After institutional review board approval, the medical records of all patients receiving an IVC filter at a single institution from 2000 to 2007 were reviewed. Age, sex, surgical approach, postoperative deep vein thrombosis (DVT), postoperative superficial thrombus, presence of pulmonary or paradoxical embolus, mortality, and IVC filter complications were all evaluated. Indications for IVC filter placement included history of DVT or PE, malignancy, hypercoagulability, prolonged immobilization, staged procedures of longer than 5 segment levels, combined anterior-posterior approaches, iliocaval manipulation during exposure, and anesthetic time of more than 8 hours. Descriptive statistics were used for the analysis of patient characteristics. Nonparametric frequency statistics (odds ratios [OR], χ) were used for analysis of main outcomes.

RESULTS

A total of 219 patients (150 women, 69 men) with a mean age of 58.8 (range, 17-86) years, were analyzed. There were 2 complications from IVC filter placement (66 Greenfield filters; 157 retrievable filters). The incidence of lower extremity DVT was 18.7% (41/219) in 36 patients. PE incidence was 3.7% (8/219 patients), and the paradoxical embolus rate was 0.5% (1 patient). Prophylactic IVC filter use reduced the odds of developing a pulmonary embolus (OR = 3.7, P < 0.05) compared with population controls. Patients receiving Greenfield filters had significantly higher VTE incidence than those receiving retrievable filters (OR = 2.8, P = 0.008). Anesthesia duration of more than 8 hours significantly increases VTE incidence (P = 0.029). No statistical significance (P < 0.05) was noted with combined anterior-posterior approach (118 patients) versus posterior-only approach (101 patients) and the incidence of DVT (24/118, 20.3% for former; 17/101, 16.8% for latter). There were a total of 14 deaths; none related to PE or paradoxical embolism during an 8-year period. Mean and median follow-up was 2.8 and 2.4 years, respectively, with 126 achieving 2 or more years of follow-up.

CONCLUSION

VTE-related morbidity and mortality have heightened the awareness within the spine community to the perioperative management of patients undergoing major spinal reconstruction. Prophylactic IVC filter placement significantly lowers VTE-related events, including PE development, than population controls.

Incidence of venous thromboembolism after spine surgery

BACKGROUND

The incidence of venous thromboembolism (VTE) has varied among studies of patients undergoing elective spine surgery. This may be because of differences in prophylaxis for VTE and differences in methods of observation. Furthermore, some studies have reported symptomatic deep vein thrombosis (DVT) or pulmonary thromboembolism (PE), whereas others have included asymptomatic DVT or PE, making comparisons difficult. Therefore, the objective of this study was to determine the incidence of symptomatic and asymptomatic PE in patients undergoing elective spine surgery and to evaluate therapeutic methods for these conditions.

METHODS

The subjects were 1975 patients who underwent spine surgery in our hospital from 1990 to 2011. Patients treated from January 1990 to November 1996 (n = 541, Group A) did not receive prophylaxis whereas those treated from January 2000 to February 2011 (n = 1,434, Group B) used a foot pump during and after surgery and subsequently wore elastic stockings. All subjects in Group A began ambulation ≥2 weeks after surgery whereas those in Group B began to walk earlier-within 3 days for patients who underwent decompression and within 1 week for those treated with fusion. From June 2010 to February 2011, contrast-enhanced computed tomography (CT) was performed 1 week after surgery for 100 patients to evaluate the presence of DVT and PE. Since March 2004, D-dimer was measured 1 week after surgery and patients with a level ≥10 μg/mL were followed up.

RESULTS

The incidence of symptomatic PE was significantly higher in Group A than in Group B (8/541, 1.5% vs. 3/1,434, 0.2%). In 3 patients in Group B, PE developed within 1 week postoperatively and D-dimer values at onset were ≤10 μg/mL. In the 100 cases examined by contrast-enhanced computed tomography (CT), asymptomatic PE and VTE were detected in 18 and 19%, respectively. The D-dimer level 1 week after surgery was ≥10 μg/mL in 105 of 841 patients; however, none of these patients had clinically symptomatic VTE for at least 3 months postoperatively.

CONCLUSIONS

Mechanical prophylaxis and early ambulation may be effective in reducing the incidence of symptomatic PE after spine surgery. Asymptomatic PE developed in 18% of patients who received mechanical prophylaxis, but the incidence of symptomatic PE was only 0.2%. Prompt diagnosis and treatment are required for patients who develop symptomatic PE.

Venous thromboembolism after thoracic/thoracolumbar spinal fusion

OBJECTIVE

Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a serious and potentially fatal surgical complication. The goal of our study was to examine preoperative characteristics, incidence, and outcomes of patients with VTE after elective thoracic/thoracolumbar level spine fusion.

METHODS

We identified 430,081 patients from the Nationwide Inpatient Sample database who underwent spinal fusion between 2002 and 2008. Patients undergoing thoracic/thoracolumbar level fusion (n = 8617) were found to have the greatest concurrent rate of VTE. We then performed multivariate analyses on this cohort to identify predictors of and outcomes after VTE in patients undergoing thoracic/thoracolumbar level fusion.

RESULTS

The overall VTE rate in spinal fusion surgery was 0.40% (cervical = 0.22%, thoracic/thoracolumbar = 1.90%, lumbar/lumbosacral = 0.49%, re-fusions = 0.64%, and fusions not otherwise specified = 0.84%). On multivariate logistic regression analysis of patients undergoing spinal fusion at the thoracic/thoracolumbar level, increasing age, Medicare insurance coverage (vs. private insurance), urban teaching hospital (vs. urban nonteaching hospital), combined anterior/posterior surgical approach (vs. posterior-only approach), and the presence of congestive heart failure or weight loss (Elixhauser comorbidity groups) were each independently associated with an increased odds ratio of VTE complication. VTE after thoracic/thoracolumbar surgery was significantly associated with longer hospital stays (16.6 vs. 6.74 days), increased total hospital costs ($260,208 vs. $115,474), and increased mortality (4.33% vs. 0.33%).

CONCLUSIONS

Multivariate logistic regression analysis reveals age, insurance status, hospital type, combined anterior/posterior surgical approach, and the presence of congestive heart failure or weight loss to be independently associated with an increased odds ratio of VTE complication. This complication is associated with increased hospital costs, length of stay, and overall mortality.