Safety of perioperative subcutaneous heparin for prophylaxis of venous thromboembolism in patients undergoing craniotomy

Early Detection and Management of Venous Thrombosis in Skull Base Surgery: Role of Routine Doppler Ultrasound Monitoring

BACKGROUND

Venous thromboembolism (VTE), encompassing deep venous thrombosis (DVT) and pulmonary embolism (PE), causes postoperative morbidity and mortality in neurosurgical patients. The use of pharmacological prophylaxis for DVT prevention in the immediate postoperative period carries increased risk of intracranial hemorrhage, especially after skull base surgeries.

OBJECTIVE

To investigate the impact of routine Doppler ultrasound monitoring in prevention and tiered management of VTE after skull base surgery.

METHODS

We retrospectively analyzed a large cohort of consecutive adult patients who were prospectively and uniformly managed with routine monitoring by Doppler ultrasound for DVT after resection of a skull base tumor.

RESULTS

A total of 389 patients who underwent 459 surgeries for intracranial tumor resection were analyzed. Skull base meningioma was the most common pathology. Forty-four (9.59%) postoperative VTEs were detected: 9 (1.96%) with PE with or without DVT and 35 (7.63%) with DVT alone. Four cases of subsegmental PE were diagnosed without evidence of lower extremity DVT, possibly in the setting of peripherally inserted central catheters maintenance. One patient had a preoperative proximal DVT and underwent a prophylactic inferior vena cava filter but expired from PE after discharge. Prior history of VTE (risk ratio [RR] 5.13; 95% CI 2.76-7.18; P < .01), anesthesia duration (RR 1.14; 95% CI 1.03-1.27; P = .02), and blood transfusion (RR 1.95; 95% CI 1.01-3.37; P = .04) were associated with VTE development on multivariate analysis.

CONCLUSION

Routine postoperative venous ultrasound monitoring detects asymptomatic DVT guiding management. This is an alternative strategy to prescribing pharmacological VTE prophylaxis immediately after lengthy surgeries for intracranial tumors. Peripherally inserted central catheters were associated with subsegmental PE.

Enhanced Recovery After Surgery (ERAS) for Cranial Tumor Resection: A Review

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncological procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential utility of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the three settings.

Optimal timing of post-operative enoxaparin after neurosurgery: A single institution experience

PURPOSE

Venous thromboembolism (VTE) is a well-known problem in patients with intracranial tumors, especially high-grade gliomas. Optimal management of VTE complications is critical given that the development of deep vein thrombosis (DVT) and/or pulmonary embolism can exacerbate medical comorbidities and increase mortality. However, little is known about the optimum time to initiate post-operative anticoagulant prophylaxis. Therefore, there is a keen interest amongst neurosurgeons to develop evidence-based protocols to prevent VTE in post-operative brain tumor patients.

METHODS

We retrospectively identified adult patients who underwent elective craniotomy for intracranial tumor resection between 2012 and 2017. Patients were categorized according to the time at which they began receiving prophylactic enoxaparin in the immediate post-operative period, within one day (POD 1), two days (POD 2), three days (POD 3), five days (POD 5), or seven days (POD 7).

RESULTS

A total of 1087 patients had a craniotomy for intracranial tumor resection between 2012 and 2017. Multivariate binomial logistic regression analysis demonstrated that initiation of prophylactic enoxaparin within 72 h of surgery was protective against the likelihood of developing a lower extremity DVT (OR: 0.32; CI: 0.10-0.95; p = 0.049) while controlling for possible risk factors for DVTs identified on univariate analysis. Furthermore, complication rates between the anticoagulation and non-anticoagulation groups were not statistically significant.

CONCLUSION

Initiating anticoagulant prophylaxis with subcutaneous enoxaparin sodium 40 mg once per day within 72 h of surgery can be done safely while reducing the risk of developing lower extremity DVT.

Posterior Fossa Hemorrhage Following the Use of Low-Molecular-Weight Heparin: Lessons Learned and Recommendations for the Treatment and Prophylaxis of Postoperative Venous Thromboembolism

Introduction Venous thromboembolism (VTE) is the most common preventable cause of morbidity and mortality among neurosurgery patients. Several studies have concluded that the use of chemical prophylaxis among patients undergoing a craniotomy reduces the incidence of VTE, and it is presumed to be safe. However, these studies do not differentiate between a supratentorial and posterior fossa craniotomy. Furthermore, the prophylactic or therapeutic use of low-molecular-weight heparin (LMWH) has been reported to increase the risk of intracranial hemorrhage. In this study, we describe the clinical details and outcomes for all patients who underwent posterior fossa craniotomy and developed posterior fossa hemorrhage secondary to postoperative use of LMWH during the study period. We also propose recommendations pertaining to postoperative heparin use after posterior fossa surgeries. Methods Data were retrospectively collected for patients presenting with posterior fossa hemorrhage following anticoagulant use among those who previously underwent posterior fossa craniotomy by the senior author (R.W.P.) from January 1, 2011, through December 31, 2018. Results We identified five patients who experienced postoperative hemorrhage while receiving LMWH in the initial setting of posterior fossa craniotomy. After hemorrhaging, four patients had low Glasgow Outcome Scale (GOS) scores (≤3) and failed to return to their baseline neurological status. These four patients had a Glasgow Coma Scale (GCS) score of 15/15 in the immediate postoperative period and received heparin within 72 hours of surgery. Conclusions Based on our findings, there is a possible association between the increased risk of hemorrhage and the early postoperative use of LMWH. The debilitating outcomes among the majority of these patients warrant the cautious use and further investigation of postoperative LMWH to appropriately quantify the risk. Further comparative studies with a larger sample size are required to provide insight into the pathophysiology of our findings.

Venous Thromboembolism in Patients With Brain Cancer: Focus on Prophylaxis and Management

Patients with primary and metastatic brain tumors are predisposed to thromboembolism. This review of the literature explores the high prevalence of venous thromboembolism and its negative impact on patients with brain cancer. It outlines the recommended prophylactic strategies to prevent venous thrombosis and analyzes the benefit versus risk of anticoagulation in this population, with a focus on the risk of intracranial bleeding associated with it. Additionally, it explores the exceedingly high prevalence of venous thromboembolism in the setting of brain cancer surgeries and provides guidance on the best methods used for prophylaxis in this setting and discusses the safety of each method perioperatively. Lastly, this review article provides guidance on how to manage venous thromboembolism in patients with brain cancer and discusses the use of vena cava filters in this population.

Venous thromboembolic events in patients undergoing craniotomy for tumor resection: incidence, predictors, and review of literature

OBJECTIVE

The authors sought to investigate the incidence and predictors of venous thromboembolic events (VTEs) after craniotomy for tumor resection, which are not well established, and the efficacy of and risks associated with VTE chemoprophylaxis, which remains controversial.

METHODS

The authors investigated the incidence of VTEs in a consecutive series of patients presenting to the authors' institution for resection of an intracranial lesion between 2012 and 2017. Information on patient and tumor characteristics was collected and independent predictors of VTEs were determined using stepwise multivariate logistic regression analysis. Review of the literature was performed by searching MEDLINE using the keywords "venous thromboembolism," "deep venous thrombosis," "pulmonary embolism," "craniotomy," and "brain neoplasms."

RESULTS

There were 1622 patients included for analysis. A small majority of patients were female (52.6%) and the mean age of the cohort was 52.9 years (SD 15.8 years). A majority of intracranial lesions were intraaxial (59.3%). The incidence of VTEs was 3.0% and the rates of deep venous thromboses and pulmonary emboli were 2.3% and 0.9%, respectively. On multivariate analysis, increasing patient age (unit OR 1.02, 95% CI 1.00-1.05; p = 0.018), history of VTE (OR 7.26, 95% CI 3.24-16.27; p < 0.001), presence of motor deficit (OR 2.64, 95% CI 1.43-4.88; p = 0.002), postoperative intracranial hemorrhage (OR 4.35, 95% CI 1.51-12.55; p < 0.001), and prolonged intubation or reintubation (OR 3.27, 95% CI 1.28-8.32; p < 0.001) were independently associated with increased odds of a VTE. There were 192 patients who received VTE chemoprophylaxis (11.8%); the mean postoperative day of chemoprophylaxis initiation was 4.6 (SD 3.8). The incidence of VTEs was higher in patients receiving chemoprophylaxis than in patients not receiving chemoprophylaxis (8.3% vs 2.2%; p < 0.001). There were 30 instances of clinically significant postoperative hemorrhage (1.9%), with only 1 hemorrhage occurring after initiation of VTE chemoprophylaxis (0.1%).

CONCLUSIONS

The study results show the incidence and predictors of VTEs after craniotomy for tumor resection in this patient population. The incidence of VTE within this cohort appears low and comparable to that observed in other institutional series, despite the lack of routine prophylactic anticoagulation in the postoperative setting.

Chemical venous thromboembolism prophylaxis in neurosurgical patients: an updated systematic review and meta-analysis

OBJECTIVE

Venous thromboembolism (VTE) is a common and potentially life-threatening complication. The risk of serious hemorrhagic complications when starting chemical prophylaxis for VTE prevention is a substantial concern for neurosurgeons. The objective of this study was to perform an updated systematic review and meta-analysis to determine if the rates of VTE and bleeding complications are different in patients undergoing chemoprophylaxis compared with placebo or mechanical prophylaxis alone following cranial or spinal procedures.

METHODS

In February 2016 a systematic literature review was performed identifying 3944 articles from 4 different databases. A random-effects meta-analysis was performed after identifying the articles that met inclusion criteria.

RESULTS

Nine articles that met the inclusion criteria were included. The quality of the studies was good, with all of them being classified as Level 2 evidence, with moderate Jadad scores. A meta-analysis comparing chemoprophylaxis with placebo in the prevention of deep venous thrombosis showed a significant benefit to chemical prophylaxis (OR 0.51, 95% CI 0.37–0.71; p < 0.0001). No significant increase in major intracranial hemorrhage (p = 0.60), major extracranial hemorrhage (p = 0.98), or minor bleeding complications (p = 0.60) was found.

CONCLUSIONS

Based on moderate-to-good quality of evidence, chemoprophylaxis is beneficial in preventing VTE, with no significant increase in either major or minor bleeding complications in patients undergoing cranial and spinal procedures. Further research is needed to determine whether this conclusion holds true for more specific subpopulations.

Risk of Deep vein thrombosis in neurosurgery: State of the art on prophylaxis protocols and best clinical practices

OBJECTIVE

To analytically discuss some protocols in Deep vein thrombosis (DVT)/pulmonary Embolism (PE) prophylaxis currently use in Neurosurgical Departments around the world.

DATA SOURCES

Analysis of the prophylaxis protocols in the English literature: An analytical and narrative review of literature concerning DVT prophylaxis protocols in Neurosurgery have been conducted by a PubMed search (back to 1978).

DATA EXTRACTION

80 abstracts were reviewed, and 74 articles were extracted.

DATA ANALYSIS

The majority of DVT seems to develop within the first week after a neurosurgical procedure, and a linear correlation between the duration of surgery and DVT occurrence has been highlighted. The incidence of DVT seems greater for cranial (7.7%) than spinal procedures (1.5%). Although intermittent pneumatic compression (IPC) devices provided adequate reduction of DVT/PE in some cranial and combined cranial/spinal series, low-dose subcutaneous unfractionated heparin (UFH) or low molecular-weight heparin (LMWH) further reduced the incidence, not always of DVT, but of PE. Nevertheless, low-dose heparin-based prophylaxis in cranial and spinal series risks minor and major postoperative haemorrhages: 2-4% in cranial series, 3.4% minor and 3.4% major haemorrhages in combined cranial/spinal series, and a 0.7% incidence of major/minor haemorrhages in spinal series.

CONCLUSION

This analysis showed that currently most of the articles are represented by case series and case reports. As long as clear guidelines will not be defined and universally applied to this diverse group of patients, any prophylaxis for DVT and PE should be tailored to the individual patient with cautious assessment of benefits versus risks.

Systematic Review of Safety and Cost-Effectiveness of Venous Thromboembolism Prophylaxis Strategies in Patients Undergoing Craniotomy for Brain Tumor

BACKGROUND

Studies have evaluated various strategies to prevent venous thromboembolism (VTE) in neuro-oncology patients, without consensus.

OBJECTIVE

To perform a systematic review with cost-effectiveness analysis (CEA) of various prophylaxis strategies in tumor patients undergoing craniotomy to determine the safest and most cost-effective prophylaxis regimen.

METHODS

A literature search was conducted for VTE prophylaxis in brain tumor patients. Articles reporting the type of surgery, choice of VTE prophylaxis, and outcomes were included. Safety of prophylaxis strategies was determined by measuring rates of VTE and intracranial hemorrhage. Cost estimates were collected based on institutional data and existing literature. CEA was performed at 30 d after craniotomy, comparing the following strategies: mechanical prophylaxis (MP), low molecular weight heparin with MP (MP+LMWH), and unfractionated heparin with MP (MP+UFH) to prevent symptomatic VTE. All costs were reported in 2016 US dollars.

RESULTS

A total of 34 studies were reviewed (8 studies evaluated LMWH, 12 for MP, and 7 for UFH individually or in combination; 4 studies used LMWH and UFH preoperatively). Overall probability of VTE was 1.49% (95% confidence interval (CI) 0.42-3.72) for MP+UFH, 2.72% [95% CI 1.23-5.15] for MP+LMWH, and 2.59% (95% CI 1.31-4.58) for MP, which were not statistically significant. Compared to a control of MP alone, the number needed to treat for MP+UFH is 91 and 769 for MP+LMWH. The risk of intracranial hemorrhage was 0.26% (95% CI 0.01-1.34) for MP, 0.74% (95% CI 0.09-2.61) for MP+UFH, and 2.72% (95% CI 1.23-5.15) for MP+LMWH, which were also not statistically significant. Compared to MP, the number needed to harm for MP+UFH was 208 and for MP+LMWH was 41. Fifteen studies were included in the final CEA. The estimated cost of treatment was $127.47 for MP, $142.20 for MP+UFH, and $169.40 for MP+LMWH. The average cost per quality-adjusted life-year for different strategies was $284.14 for MP+UFH, $338.39 for MP, and $722.87 for MP+LMWH.

CONCLUSION

Although MP+LMWH is frequently considered the optimal prophylaxis for VTE risk reduction, our model suggests that MP+UFH is the safest and most cost-effective measure to balance VTE and hemorrhage risks in brain tumor patients at lower risk of hemorrhage. MP+LMWH may be more effective for patients at higher risk of VTE.

Prophylaxis of Venous Thrombosis in Neurocritical Care Patients: An Evidence-Based Guideline: A Statement for Healthcare Professionals from the Neurocritical Care Society

The risk of death from venous thromboembolism (VTE) is high in intensive care unit patients with neurological diagnoses. This is due to an increased risk of venous stasis secondary to paralysis as well as an increased prevalence of underlying pathologies that cause endothelial activation and create an increased risk of embolus formation. In many of these diseases, there is an associated risk from bleeding because of standard VTE prophylaxis. There is a paucity of prospective studies examining different VTE prophylaxis strategies in the neurologically ill. The lack of a solid evidentiary base has posed challenges for the establishment of consistent and evidence-based clinical practice standards. In response to this need for guidance, the Neurocritical Care Society set out to develop and evidence-based guideline using GRADE to safely reduce VTE and its associated complications.

Clinical features and risk factor analysis for lower extremity deep venous thrombosis in Chinese neurosurgical patients

Background:

Deep venous thrombosis (DVT) contributes significantly to the morbidity and mortality of neurosurgical patients; however, no data regarding lower extremity DVT in postoperative Chinese neurosurgical patients have been reported.

Materials and Methods:

From January 2012 to December 2013, 196 patients without preoperative DVT who underwent neurosurgical operations were evaluated by color Doppler ultrasonography and D-dimer level measurements on the 3^rd, 7^th, and 14^th days after surgery. Follow-up clinical data were recorded to determine the incidence of lower extremity DVT in postoperative neurosurgical patients and to analyze related clinical features. First, a single factor analysis, Chi-square test, was used to select statistically significant factors. Then, a multivariate analysis, binary logistic regression analysis, was used to determine risk factors for lower extremity DVT in postoperative neurosurgical patients.

Results:

Lower extremity DVT occurred in 61 patients, and the incidence of DVT was 31.1% in the enrolled Chinese neurosurgical patients. The common symptoms of DVT were limb swelling and lower extremity pain as well as increased soft tissue tension. The common sites of venous involvement were the calf muscle and peroneal and posterior tibial veins. The single factor analysis showed statistically significant differences in DVT risk factors, including age, hypertension, smoking status, operation time, a bedridden or paralyzed state, the presence of a tumor, postoperative dehydration, and glucocorticoid treatment, between the two groups (P < 0.05). The binary logistic regression analysis showed that an age greater than 50 years, hypertension, a bedridden or paralyzed state, the presence of a tumor, and postoperative dehydration were risk factors for lower extremity DVT in postoperative neurosurgical patients.

Conclusions:

Lower extremity DVT was a common complication following craniotomy in the enrolled Chinese neurosurgical patients. Multiple factors were identified as predictive of DVT in neurosurgical patients, including the presence of a tumor, an age greater than 50 years, hypertension, and immobility.

Complications of glioma surgery

Even with current advances in adjunctive therapies, including radiation, chemotherapy, and various clinical trials of gene therapy and immunotherapy, surgical resection remains one of the most effective treatment for intra-axial gliomas. Survival in these patients has been shown to be related to the extent of resection. In some cases, it can provide cures of long-term remission; in others, it can provide disease control when combined with the above adjunctive treatments. However, surgical resection carries its own risks and complications. These complications can be broadly divided into neurologic, regional, and systemic, including direct cortical and vascular injury, surgical wound complications, and postsurgical medical complications. Certain patient characteristics, including Karnofsky performance status score (KPS) and pathology of the tumor, have been shown to have an impact on the risk of postsurgical complications. Advancement in preoperative and intraoperative adjunct technology such as cortical mapping and navigation has improved the surgeon's ability to safely and maximally resect the tumors. It is therefore important to understand the perioperative complications after craniotomy and tumor resection and factors affecting morbidity and mortality in order for surgeons to optimally select and counsel patients who will benefit the most from surgical resection. This chapter will focus on the complications associated with craniotomy for intrinsic glioma and ways of avoiding these events.

Heparin and related drugs for venous thromboembolism prophylaxis: subcutaneous or intravenous continuous infusion?

In this article, the most evidenced approaches of unfractionated heparin administration for prevention of venous thromboembolism in medical and surgical hospitalized patients will be reviewed. Present data were collected by searching Scopus, PubMed, MEDLINE, Science direct, Clinical trials and Cochrane database systematic reviews. Subcutaneous low doses of unfractionated heparin (10000–15000 IU) in two or three divided doses per day are commonly administrated for venous thromboembolism prevention in different medical and surgical populations. In some populations such as obese surgical and critically ill patients, due to altered pharmacokinetics behavior of unfractionated heparin, continuous intravenous infusion of the low doses of unfractionated heparin has been proposed.

Reduction of thromboembolic events in meningioma surgery: a cohort study of 724 consecutive patients

Background

Meningiomas are associated with the highest postoperative rate of venous thromboembolic events (VTE) among all intracranial tumors. The aim of this study is to compare two entirely different VTE prophylaxis regimens in 724 consecutive patients undergoing meningioma surgery.

Methods

Two cohorts at a single institution treated with different regimens to prevent VTE were reviewed retrospectively. Cohort A (n = 482; 314 females, mean age 57 years, range: 11–87 years) received our institutional regimen during the years 1999–2006, consisting of low-molecular-weight heparin (LMWH) and compression stockings. For cohort B (n = 242; 163 females, mean age 56.8 years, range: 16–90 years), during the years 2008–2010, the management included intraoperative 10°–20° leg elevation with intermittent pneumatic compression (IPC), heparin and LMWH administration. We compared the incidence of the endpoints pulmonary embolism (PE), deep venous thrombosis (DVT), hemorrhage and death, taking into account several known associated risk factors.

Results

For all endpoints, we observed a more favorable outcome with the new regimen. The difference in incidence of PEs (cohort A: 38/482, 8%; cohort B: 6/242, 2.5%) reached statistical significance (p = 0.002). In general, patients with skull base meningiomas had a higher risk for PE (OR 2.77). Regarding VTE prophylaxis, an adjusted subgroup analysis suggests that the new regimen is particularly beneficial for patients with skull base meningiomas.

Conclusions

We recommend perioperative prophylaxis using a management composed of intraoperative leg-elevation, IPC, early heparin administration and LMWH to reduce the risk for PE.

Subcutaneous heparin for prophylaxis of venous thromboembolism in deep brain stimulation surgery: evidence from a decision analysis

OBJECTIVE

The addition of subcutaneous heparin (SQH) to mechanical prophylaxis for venous thromboembolism (VTE) involves a balance between the benefit of greater protection from VTE and the added risk of intracranial hemorrhage. There is evidence that the hemorrhage risk outweighs the benefits for patients undergoing craniotomy. We investigated the safety of SQH in patients undergoing deep brain stimulation (DBS) surgery.

METHODS

A retrospective analysis was performed of all patients with movement disorders (n = 254) undergoing DBS surgery at our institution from 2003 to 2007. Before September 2005, none of the patients undergoing DBS received SQH (non-SQH group) (n = 121). Thereafter, all patients were administered SQH perioperatively (SQH group) (n = 133). All patients wore graduated compression stockings and pneumatic compression boots postoperatively in bed. A postoperative brain magnetic resonance imaging scan was obtained on the day of surgery.

RESULTS

Five (3.8%) of 133 SQH patients and 1 (0.8%) of 121 non-SQH patients developed asymptomatic intracranial hemorrhage. None of the SQH patients developed clinically significant VTE, whereas 3 (2.5%) non-SQH patients developed VTE (1 deep venous thrombosis, 2 pulmonary embolisms). Using a decision-analysis model, we have shown that the use of SQH plus mechanical prophylaxis together yielded outcomes at least as good as mechanical prophylaxis alone.

CONCLUSION

Our findings suggest that SQH for VTE prophylaxis in patients with movement disorders undergoing DBS surgery is safe. SQH protects against VTE in this patient population and merits further investigation.

Hemostatic and hemorrhagic problems in neurosurgical patients

BACKGROUND

Abnormalities of the hemostasis can lead to hemorrhage, and on the other hand to thrombosis. Intracranial neoplasms, complex surgical procedures, and head injury have a specific impact on coagulation and fibrinolysis. Moreover, the number of neurosurgical patients on medication (which interferes with platelet function and/or the coagulation systems) has increased over the past years.

METHOD

The objective of this review is to recall common hemostatic disorders in neurosurgical patients on the basis of the "new concept of hemostasis". Therefore the pertinent literature was searched to provide a structured and up to date manuscript about hemostasis in Neurosurgery.

FINDINGS

According to recent scientific publications abnormalities of the coagulation system are discussed. Pathophysiological background and the rational for specific (cost)-effective perioperative hemostatic therapy is provided.

CONCLUSIONS

Perturbations of hemostasis can be multifactorial and maybe encountered in the daily practice of neurosurgery. Early diagnosis and specific treatment is the prerequisite for successful treatment and good patients outcome.

Incidence of deep venous thrombosis after subarachnoid hemorrhage

Object

The aim of this study was to determine the efficacy of venous ultrasonography in screening for deep venous thrombosis (DVT) after subarachnoid hemorrhage (SAH). A large cohort of patients who had suffered SAH was evaluated with the primary end points of ascertaining the incidence of asymptomatic DVT with venous Doppler ultrasonography screening and of identifying risk factors for the development of DVT and subsequent pulmonary embolism.

Methods

Data from patients with aneurysmal SAH who had been admitted to the neurosurgical intensive care unit (ICU) between December 2002 and October 2006 were retrospectively evaluated. Patients who had undergone surgical or endovascular treatment of an aneurysm following SAH and survived ≥ 15 days were included in the study.

Results

The overall incidence of DVT among the entire study cohort was 18%. A subgroup analysis identified all patients, with or without symptoms for DVT, who had undergone venous Doppler ultrasonography screening. The incidence of asymptomatic DVT was 24%. Univariate analysis of all patients revealed a significant correlation between the risk of DVT and Hunt and Hess grade (r = 0.38, p < 0.0001), Fisher grade (r = 0.31, p < 0.0001), total hospital stay (r = 0.49, p < 0.0001), and number of days in the ICU (r = 0.48, p < 0.0001). Multivariate analysis demonstrated that the total hospital stay and number of days in the ICU were significant predictors of DVT in all patients (p < 0.0001 and p < 0.0002, respectively). In the subgroup of screened patients, Hunt and Hess grade, total hospital stay, and number of days in the ICU were significant predictors of DVT. Although screened patients were more likely to have DVT (χ2 = 6.0976, p < 0.02), there was no significant difference in the incidence of DVT or pulmonary embolism between patients who did and those who did not undergo routine lower-extremity Doppler ultrasonography screening.

Conclusions

Routine compressive venous Doppler ultrasonography is an efficient, noninvasive means of identifying DVT as a screening modality in both symptomatic and asymptomatic patients following aneurysmal SAH. The ability to confirm or deny the presence of DVT in this patient population allows one to better identify the indications for chemoprophylaxis. Prophylaxis for venous thromboembolism in neurosurgical patients is common. Emerging literature and anecdotal experience have exposed risks of complications with prophylactic anticoagulation protocols. The identification of patients at high risk—for example, those with asymptomatic DVT—will allow physicians to better assess the role of prophylactic anticoagulation.

Symptomatic venous thromboembolism: incidence and risk factors in patients with spontaneous or traumatic intracranial hemorrhage

OBJECTIVES

The objectives of this study are to determine the incidence of symptomatic venous thromboembolism (VTE) in neurosurgery intensive care unit (NSICU) patients with spontaneous or traumatic intracranial hemorrhage and to identify the common VTE risk factors by injury type.

METHODS

This retrospective, single-center cohort study included adult patients admitted to the NSICU between January 2001 and July 2004 with a primary diagnosis of subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), or traumatic brain injury (TBI). Patients and VTE events were identified using ICD-9 codes. All patients received low-dose unfractionated heparin or enoxaparin and intermittent pneumatic compression device. Descriptive statistics were used to describe patient characteristics.

RESULTS

The overall incidence of symptomatic VTE was 3.8% (n = 1195). The incidence of VTE was 6.7% in SAH patients (n = 179), 2.9% in ICH patients (n = 516), and 3.8% in TBI patients (n = 500). The most commonly identified risk factors in the three groups were: greater than 40 years of age, immobility due to paresis or restrictions for mechanical ventilation, presumed infection, and presence of indwelling central venous catheter. There was no objective evidence of intracranial bleeding associated with pharmacologic VTE prophylaxis in VTE patients.

CONCLUSION

This is the first study to determine symptomatic VTE incidence and to identify common risk factors by injury type in nontumor patients who are not routinely screened with venous duplex ultrasonography but receiving early IPC and LDUH. Further studies are needed to determine the overall incident of symptomatic and nonsymptomatic VTE and independent risk factors for VTE events in NSICU patients.

Venous thromboembolism occurs infrequently in meningioma patients receiving combined modality prophylaxis

BACKGROUND

Individuals with brain tumors have an increased risk of venous thromboembolism (VTE). Within this population, patients with meningiomas have been reported to have the highest incidence, exceeding rates associated with gliomas and brain metastases. However, earlier studies did not employ VTE prophylaxis, and VTE were detected with radionuclide scans, the reliability of which has since been questioned. Therefore, we conducted a retrospective review of postoperative meningioma patients receiving contemporary VTE prophylaxis and diagnostic methods to define the current incidence of and risk factors for symptomatic VTE in this population.

METHODS

Medical records were reviewed from all patients undergoing craniotomy for meningioma at Johns Hopkins Hospital in 2004 and 2005. The association between clinical characteristics and VTE was assessed using parametric and nonparametric statistical tests and survival analysis.

RESULTS

A total of 224 individuals met criteria for the review. The mean age was 52 years (standard deviation [SD] 14 years), and 167 patients (75%) were women. Median follow-up time was 230 days (interquartile range [IQR], 89-428 days). VTE was diagnosed in 11 patients (4.9%; 95% confidence interval, 2.5%-8.6%) at a median of 16 days (IQR, 7-33 days) postoperatively. The development of VTE was associated with older age (mean, 68 years vs 52 years; P = .0001), male gender (P = .007), and nonambulatory status postoperatively (P < .0001).

CONCLUSIONS

VTE occurs infrequently in postoperative meningioma patients who receive combined modality VTE prophylaxis. VTE risk factors in these patients include advanced age, male gender, and nonambulatory status postoperatively.

Postoperative dural sinus thrombosis in a patient in a hypercoagulable state

✓ Spontaneous cerebral venous sinus thrombosis is a rare problem that may be encountered in patients with underlying thrombophilic disorders. It has also been reported as a postoperative complication following suboccipital, transpetrosal, and transcallosal approaches. The authors report on a 67-year-old man with two prior episodes of lower-extremity deep venous thrombosis who underwent transcallosal resection of a colloid cyst and in whom sagittal sinus thrombosis developed 2 weeks thereafter. Results of a subsequent hematological workup revealed both a factor V Leiden mutation and the presence of antiphospholipid antibodies, two thrombophilic risk factors that likely contributed to the development of delayed postoperative sinus thrombosis. Although the safety of low-molecular-weight heparin (LMWH) after craniotomy has not been established in a randomized, controlled study, there is sufficient evidence to justify its use for prophylactic anticoagulation therapy in patients at high risk for postoperative cerebral venous thrombosis. The authors propose using LMWH prophylaxis in patients with thrombophilic disorders who undergo neurosurgical procedures in proximity to dural sinuses in an effort to prevent catastrophic venous infarction.

Management of venous thromboembolism in patients with primary and metastatic brain tumors

Venous thromboembolism occurs commonly throughout the clinical course of patients with brain tumors. A number of hemostatic and clinical factors contribute to this hypercoagulable state. Concern over the possibility of intracranial bleeding has limited the use of anticoagulation in this population. However, mechanical approaches such as vena cava filters have high complication and treatment failure rates in patients with intracranial malignancies. In addition, the available data suggest that anticoagulation can be used safely and effectively in most of these patients. Patients with thrombocytopenia, recent neurosurgery, and tumor types prone to bleeding require special consideration. When intracranial hemorrhage does occur, it is often due to overanticoagulation, requiring prompt anticoagulation reversal and neurosurgical consultation.

A review of the risks and benefits of differing prophylaxis regimens for the treatment of deep venous thrombosis and pulmonary embolism in neurosurgery

BACKGROUND

Annually, 2 million people in the United States develop deep venous thrombosis (DVT), and nearly 100,000 sustain fatal pulmonary emboli. Prophylaxis against DVT/pulmonary embolism (PE) is a critical issue, and options include elastic stockings, intermittent pneumatic compression stockings, low-dose unfractionated heparin (5000 U every 8-12 hours), and low molecular-weight heparin (ie, enoxaparin and dalteparin). The risks and benefits associated with different prophylaxis regimens used in the prevention of DVT and PE in neurosurgical procedures were analyzed.

METHODS

Neurosurgical studies focusing on different methods of prophylaxis used for the prevention of DVT and PE were reviewed. The efficacy, risks, and benefits of varied treatment options were evaluated, with particular emphasis on minor and major hemorrhages occurring where heparin-based protocols were used.

RESULTS

In Flinn et al series (Arch Surg. 1996;131(5):472-80), the incidence of DVT was greater for cranial (7.7%) than spinal procedures (1.5%). Although intermittent pneumatic compression devices provided adequate reduction of DVT/PE in some cranial and combined cranial/spinal series, low-dose subcutaneous unfractionated heparin or low molecular-weight heparins further reduced the incidence, not always of DVT, but of PE (Br J Neurosurg 1995;9(2):159-63; J Intensive Care Med 2003;18(2):59-79). Nevertheless, low-dose heparin-based prophylaxis in cranial and spinal series risks minor and major postoperative hemorrhages: 2% to 4% in a cranial series, 3.4% minor and 3.4% major hemorrhages in a combined cranial/spinal series, and a 0.7% incidence of major/minor hemorrhages in a spinal series (J Neurosurg 2003;99(4):680-4; Neurosurgery 1986;18(4):440-5; Eur Spine J 2004;13(1):1-8; J Intensive Care Med 2003;18(2):59-79).

CONCLUSIONS

Although mechanical prophylaxis provided effective prophylaxis against DVT/PE in many series, the added efficacy of low-dose heparin regimens has to be weighed against risks of major postoperative hemorrhages and their neurological sequelae.

Intermittent pneumatic compression stocking prophylaxis against deep venous thrombosis in anterior cervical spinal surgery: a prospective efficacy study in 200 patients and literature review

STUDY DESIGN

Intermittent pneumatic compression stockings (IPC) alone were prospectively used to avoid deep venous thrombosis (DVT) and pulmonary embolism (PE) in 100 consecutive patients undergoing single-level anterior corpectomy/fusion (ACF) and in 100 patients having multilevel ACF/posterior fusion.

OBJECTIVES

To determine the optimal prophylaxis against DVT and PE for patients undergoing anterior cervical spinal surgery.

BACKGROUND DATA

Mini-heparin and low-dose heparin prophylaxis in neurosurgery poses a 2% to 4% risk of major postoperative hemorrhage with resultant neurologic sequelae.

METHODS

Prophylaxis consisted of IPC alone. Doppler studies of the lower extremities were routinely obtained 2 days after surgery. Single-level ACF (100 patients) addressed two-level disc disease, spondylostenosis, and ossification of the posterior longitudinal ligament (OPLL). One hundred patients undergoing multilevel ACF (3+ levels) with posterior fusion (C2-T1) exhibited OPLL/spondylostenosis.

RESULTS

One patient undergoing single-level ACF developed DVT/PE 6 days after surgery; she exhibited Factor V Leiden mutation (hypercoagulability syndrome). Although 7 patients undergoing circumferential surgery developed DVT 2 to 14 days following surgery (mean, 7.15 days), only two clots localized in the iliac veins resulted in PEs (days 10 and 14 after surgery).

CONCLUSIONS

IPCs were as effective for prophylaxis against DVT/PE for 100 patients undergoing single-level ACF and for 100 having circumferential procedures as existing therapies (mini-heparin and low-dose heparin), without the risk of hemorrhage. However, the 1% and 2% respective rates of PE were comparable to frequencies of PE encountered in other cranial/spinal series using mini-heparin and/or low-dose heparin regimens but avoided the 2% to 4% risk of major postoperative hemorrhage.

Thromboprophylaxie en neurochirurgie et en neurotraumatologie intracrânienne

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.

Treatment of medical complications in patients with brain tumors

Patients with primary brain tumors and those with cerebral metastases are at risk throughout their illness for several major medical problems, including vasogenic edema, seizures, and symptomatic venous thrombosis. In turn, the corticosteroids, anti-epileptic drugs, and anticoagulants used to treat these problems may produce significant adverse effects and result in important drug-drug interactions that may complicate chemotherapy. Although few Class I studies address any of these issues, guidelines can be offered to maximize quality of life and minimize hospital readmissions. Optimal management of brain edema involves minimizing corticosteroid use and tapering the steroid dose slowly to avoid steroid withdrawal symptoms. Prophylaxis of Pneumocystis pneumonia is necessary for patients requiring corticosteroids for more than 1 month. Anti-epileptic drugs (AEDs) should be avoided unless patients experience seizures. If possible, non-CTY (P450) enzyme-inducing drugs should be chosen. AED levels should be obtained frequently during corticosteroid taper. Multimodality venous thrombosis prophylaxis should begin at the time of the original surgery with external leg compression and unfractionated subcutaneous heparin or a low molecular weight heparin (LMWH). Brain tumor patients with symptomatic venous thrombosis or pulmonary embolism can be anticoagulated safely with warfarin or with LMWH, and LMWHs are preferable from the standpoints of efficacy, safety, and convenience for long-term outpatient treatment of venous thrombosis. Clinicians should be aware of potential drug-drug interactions between prescribed AEDs and chemotherapy and possible interactions with complementary and alternative therapies chosen by their patients. They also should be aware of interventions to minimize late sequelae of brain tumors and their treatment, including cognitive decline, depression, and increased stroke risk.

Prophylaxis for Deep Venous Thrombosis in Craniotomy Patients: A Decision Analysis

OBJECTIVE:

We sought to determine the most efficient perioperative prophylactic strategy for deep venous thrombosis (DVT) in craniotomy patients by use of a decision analysis model.

METHODS:

We conducted a structured review of the relevant literature and compiled the reported incidences of DVT, pulmonary embolism, and postoperative intracranial hemorrhage (ICH) in craniotomy patients. We also obtained from the literature estimates of the likelihood and the impact of various outcomes of these complications. Data from 810 craniotomies performed at our own institution were also examined. The decision analytic model was then used to compare the effectiveness of pneumatic compression boots with pneumatic compression boots combined with either unfractionated or low-molecular-weight heparin. The model dealt with variability by using both sensitivity analysis and Monte Carlo simulation.

RESULTS:

As expected, the addition of heparin lowered the incidence of both DVT and pulmonary embolism, but at the cost of increasing ICH. Because the deleterious effects of ICH were so much greater than the benefits from heparinization, overall outcomes were best with mechanical prophylaxis alone. This was especially true for low-molecular-weight heparin, which is associated with a relatively high risk of ICH. Our own institutional data support the findings in the literature. Although the differences are modest, they reach statistical significance in the case of low-molecular-weight heparin.

CONCLUSION:

Using decision analytic modeling, we have shown that mechanical prophylaxis yields outcomes in craniotomy patients superior to those of either unfractionated or low-molecular-weight heparin.

The management of thromboembolic disease in patients with central nervous system malignancies

Venous thromboembolic disease (VTE) is a common complication of malignancies affecting the central nervous system (CNS), both in the perioperative period and throughout the disease course. Until recently, the perceived risk of intracranial hemorrhage in patients with CNS malignancies was felt to be a relative contraindication to systemic anticoagulation, and most patients were managed with nonpharmacologic methods in both the prophylactic and treatment setting. However, several studies of the safety and efficacy of anticoagulation in both neurosurgical and cancer patients have challenged the previous dogma, and routine use of unfractionated heparin or low molecular weight heparin (LMWH) for VTE prophylaxis in patients undergoing craniotomy for CNS malignancy is recommended. Likewise, treatment of established VTE in this population with heparins is recommended, at least initially, followed by long-term treatment either with heparin or oral warfarin. Complications of inferior vena cava (IVC) filters, used as an alternative to systemic anticoagulation, appear to be more common in brain tumor patients with VTE, lending further support to treatment with systemic anticoagulation when possible. We advocate a multimodality approach utilizing compression stockings, intermittent compression devices, and heparin in the perioperative setting as the best proven method to reduce the risk of VTE. In the absence of a strict contraindication to systemic anticoagulation, such as previous intracranial hemorrhage or profound thrombocytopenia, LMWH is recommended in brain tumor patients with newly diagnosed VTE, followed by long-term warfarin or LMWH.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

Prophylaxis for deep venous thrombosis in neurosurgical oncology: review of 2779 admissions over a 9-year period

Object

Management of disease in patients undergoing neurosurgical treatment for tumors requires balancing the competing risks of hemorrhage and thrombosis. The authors compared the incidence of clinically apparent deep venous thrombosis (DVT) and pulmonary embolism (PE) in patients admitted for treatment of intracranial and spinal tumors at three institutions. At the public hospital (the Royal North Shore Hospital [RNSH]) nonsequential calf compression was used, and at the other two private neurosurgery services sequential calf compression with low-molecular-weight heparin was used in patients undergoing spinal surgery. All patients wore compression stockings and underwent follow-up scanning after surgery.

Methods

The authors identified from their neurosurgery databases 2779 discharges of patients with tumor from the RNSH and private hospitals between January 1, 1995 and December 31, 2003. Patient admissions were relatively well matched for age, sex, duration of stay, and tumor type. For patients who underwent spinal surgery, the incidence of DVT was higher in the RNSH (2.6% of admissions) than in private hospitals, where no case of DVT was seen (p = 0.02). The incidence of PE was higher in admissions patients who had been treated for cranial tumors in the RNSH (2.9%) than in those treated in the private hospitals (1.3%, p = 0.01).

Possible reasons for these discrepancies include a higher proportion of ambulatory patients before and after surgery in the group treated at private hospitals. More emergency and semi-emergency surgery was performed in the RNSH than in the private hospitals. Nevertheless, fewer patients discharged from the RNSH had undergone surgery, which is a known risk factor for DVT.

Conclusions

Patients with intracranial tumors had a higher incidence of PE than those with spinal tumors. The incidence of DVT and PE was higher in patients admitted to the public hospital. The incidence of DVT in patients undergoing spinal procedures was lower when low-molecular-weight heparin was used judiciously, but the incidence of PE in patients undergoing cranial procedures was lower with the private hospital protocol, which did not include prophylaxis with anticoagulating agents.

Prophylaxis for deep venous thrombosis in patients with craniotomies: a review

Deep venous thrombosis (DVT) remains a source of significant morbidity and mortality in patients who undergo craniotomy procedures. Despite several studies in which the safety and efficacy of various prophylactic strategies were examined, there is still no consensus among clinicians. In this paper the authors review the literature with regard to epidemiological and pathophysiological features, screening methods, and prophylactic measures for DVT.

Venous thromboembolism prophylaxis after head and spinal trauma: intermittent pneumatic compression devices versus low molecular weight heparin

Although there are alternative methods and drugs for preventing venous thromboembolism (VTE), it is not clear which modality is most suitable and efficacious for patients with severe (stable or unstable) head/spinal injures. The aim of this study was to compare intermittent pneumatic compression devices (IPC) with low-molecular-weight heparin (LMWH) for preventing VTE. We prospectively randomized 120 head/spinal traumatized patients for comparison of IPC with LMWH as a prophylaxis modality against VTE. Venous duplex color-flow Doppler sonography of the lower extremities was performed each week of hospitalization and 1 week after discharge. When there was a suspicion of pulmonary embolism (PE), patients were evaluated with spiral computed tomography. Patients were analyzed for demographic features, injury severity scores, associated injuries, type of head/spinal trauma, complications, transfusion, and incidence of deep venous thrombosis (DVT) and PE. Two patients (3.33%) from the IPC group and 4 patients (6.66%) from the LMWH group died, with their deaths due to PE. Nine other patients also succumbed, unrelated to PE. DVT developed in 4 patients (6.66%) in the IPC group and in 3 patients (5%) in the LMWH group. There was no statistically significant difference regarding a reduction in DVT, PE, or mortality between groups ( p = 0.04, p > 0.05, p > 0.05, respectively). IPC can be used safely for prophylaxis of VTE in head/spinal trauma patients.

Reduction of ischemic sequelae following spontaneous subarachnoid hemorrhage: a double-blind, randomized comparison of enoxaparin versus placebo

BACKGROUND

Cerebral vasospasm, including its ischemic sequelae, remains a leading cause of death and disability following subarachnoid hemorrhage (SAH). This study was designed to evaluate whether the low-molecular-weight heparin (LMWH) enoxaparin reduces the occurrence of cerebral vasospasm and ischemia following spontaneous SAH.

METHODS

A prospective, double-blind, randomized study was conducted in 120 consecutive patients with SAH (Hunt Hess Scale (HHS) I-III). Patients received one subcutaneous injection per day of either 20mg enoxaparin or placebo for 3 weeks following SAH. Efficacy endpoints were the occurrence of cerebral vasospasm, delayed ischemic deficit (DID), cerebral infarction, and overall outcome at 1 year following SAH.

RESULTS

At 1-year follow-up, enoxaparin significantly reduced DID and cerebral infarction. Delayed ischemic deficit occurred in 8.8% of the enoxaparin group versus 66.7% of the placebo group (P<0.001), while 3.5% of vasospasm-related cerebral infarctions occurred in enoxaparin-treated patients and 28.3% in placebo-treated patients (P<0.001). Severe shunt-dependent hydrocephalus was significantly lower in the enoxaparin group (1.8% versus 16.7%; P=0.019). Compared with the placebo group, the enoxaparin group had fewer intracranial bleeding events and better overall outcomes at 1-year follow-up. Although there was potential bias as a result of patients in the placebo group being more severely affected (in terms of HHS), treatment with enoxaparin for 3 weeks improved long-term outcome following SAH.

CONCLUSIONS

Enoxaparin is safe and effective in reducing cerebral vasospasm and ischemia following SAH (Hunt Hess grades I-III), resulting in a better long-term outcome for the patient.

Incidence of venous thromboembolism in patients undergoing craniotomy and motor mapping for glioma without intraoperative mechanical prophylaxis to the contralateral leg

OBJECT

Evidence-based reviews support the use of venous thromboembolism (VTE) prophylaxis in the form of compression devices and/or stockings for patients undergoing craniotomy. In patients undergoing craniotomy with motor mapping for glioma, the contralateral lower extremity should remain visible so that motor responses can be accurately identified. As a consequence, these patients could be placed at a higher risk to develop VTE. The authors have quantified the incidence of VTE in patients undergoing craniotomy with motor mapping and have shown that there is no increased risk of developing a VTE in the contralateral lower extremity when compression devices are not used.

METHODS

One hundred eighty consecutive cases (1997-2000) of craniotomy with motor mapping for glioma were retrospectively reviewed to determine the incidence and location of VTEs during the early postoperative course. Intraoperative VTE prophylaxis in all patients consisted of ipsilateral (that is, ipsilateral to the hemisphere being mapped) lower-extremity mechanical prophylaxis (antiembolism stocking plus compression device). Postoperatively, all patients received bilateral mechanical prophylaxis. Patients were observed until discharge and received clinical follow up. Venous thromboembolism, classified as deep venous thrombosis (DVT) or pulmonary embolism (PE) occurring within 6 weeks postoperatively, was confirmed by Doppler ultrasonography, spiral computerized tomography scanning, or both. The average duration of postoperative hospitalization was 5 days (range 2-59 days). Six patients (3.3%) experienced VTE. Of those, in four (2.2%) the DVT was localized to the contralateral (three patients) or ipsilateral (one patient) lower extremity. Two other patients (1.1%) only had PE. There were no deaths from thromboembolic complications and no statistically significant predisposition to VTE in the contralateral lower extremity among patients not receiving intraoperative prophylaxis.

CONCLUSIONS

The incidence of VTE in patients undergoing craniotomy with motor mapping is comparable to that in patients receiving bilateral lower-extremity mechanical VTE prophylaxis. The practice of leaving the contralateral lower extremity free from intraoperative prophylaxis does not appear to place patients at a higher risk for developing VTE. There appears to be no preferential distribution of VTE in contralateral lower extremities that do not receive immediate preoperative and intraoperative mechanical prophylaxis.

Risk of Postoperative Hemorrhage after Intracranial Surgery after Early Nadroparin Administration: Results of a Prospective Study

OBJECTIVE

Early postoperative pharmacological prophylaxis of deep vein thrombosis after intracranial surgery is still a matter of debate because of concerns regarding the formation of postoperative hematoma. The objective of this study was to prospectively analyze the rate of postoperative hemorrhage during a 3-year period of early postoperative administration of the low molecular weight heparin nadroparin (Fraxiparin) plus compression stockings in a large cohort of patients undergoing intracranial surgery.

METHODS

A total of 2823 intracranial neurosurgical procedures, performed between June 1999 and 2002, were studied. Of these operations, 1319 (46.7%) were major intracranial surgical procedures (Group 1). Group 2 comprised 1504 operations (53.3%) considered to be minor surgical procedures (e.g., shunt procedures, biopsies). All patients except those with transnasal transsphenoidal removal of pituitary tumors underwent early postoperative imaging (computed tomography or magnetic resonance imaging) to determine postoperative hemorrhage. All significant postoperative hematomas (defined as those requiring surgical evacuation because of relevant space occupation and/or neurological deterioration) were treated surgically. Prophylaxis of venous thromboembolic events included early (&lt;24 h) postoperative administration of 0.3 ml nadroparin subcutaneously plus intra- and postoperative compression stockings until discharge.

RESULTS

Forty-three major postoperative hemorrhages (1.5%) were observed after 2823 intracranial procedures (95% confidence interval, 1.1–2.05). Forty-two (3.2%) of 1319 postoperative hematomas occurred in patients undergoing major intracranial procedures (Group 1). There was only 1 (0.07%) significant hemorrhage after 1504 minor intracranial procedures (Group 2). A subgroup analysis of patients who needed preoperative anticoagulation because of medical comorbidity did not reveal an increased frequency of postoperative hematoma when anticoagulation was stopped 24 hours before surgery P = 0.1, χ2 test; 95% confidence interval, 0.89–3.0).

CONCLUSION

This report describes the largest prospective study conducted to date to determine the hemorrhage rate after early postoperative anticoagulation. The results support the concept of postoperative pharmacological thromboembolic prophylaxis in patients undergoing intracranial surgery.

Randomized, pilot study of intermittent pneumatic compression devices plus dalteparin versus intermittent pneumatic compression devices plus heparin for prevention of venous thromboembolism in patients undergoing craniotomy

BACKGROUND

Unfractionated heparin and the low molecular weight heparin, dalteparin, are used for prophylaxis against venous thromboembolism in patients undergoing craniotomy. These drugs were compared in a randomized, prospective pilot study comparing intermittent pneumatic compression devices plus dalteparin to intermittent pneumatic compression devices plus heparin.

METHODS

One hundred patients undergoing craniotomy were randomly allocated to receive perioperative prophylaxis with subcutaneous (SC heparin, 5000 units every 12 hours, or dalteparin, 2,500 units once a day, begun at induction of anesthesia and continued for 7 days or until the patient was ambulating. Entry criteria were age over 18 years, no deep vein thrombosis (DVT) preoperatively as judged by lower limb duplex ultrasound and no clinical evidence of pulmonary embolism preoperatively. Patients with hypersensitivity to heparin, penetrating head injury or who refused informed consent were excluded. Patients underwent a duplex study 1 week after surgery and 1 month clinical follow-up. All patients were treated with lower limb intermittent pneumatic compression devices.

RESULTS

There were no differences between groups in age, gender, and risk factors for venous thromboembolism. There were no differences between groups in intraoperative blood loss, transfusion requirements or postoperative platelet counts. Two patients receiving dalteparin developed DVT (one symptomatic and one asymptomatic). No patient treated with heparin developed DVT and no patient in either group developed pulmonary embolism. There were two hemorrhages that did not require repeat craniotomy in patients receiving dalteparin and one that did require surgical evacuation in a patient treated with heparin. Drug was stopped in two patients treated with dalteparin because of thrombocytopenia. None of these differences were statistically significant.

CONCLUSION

There was no significant difference in postoperative hemorrhage, venous thromboembolism or thrombocytopenia between heparin and dalteparin. The results suggest that, given the small sample size of this trial, both drugs appear to be safe and the incidence of venous thromboembolism by postoperative screening duplex ultrasound appears to be low when these agents are used in combination with intermittent pneumatic compression devices.

The evolution and impact of the American College of Chest Physicians consensus statement on antithrombotic therapy

The evolution of the American College of Chest Physicians consensus on antithrombotic therapy is reviewed, specifically with regard to the prevention and treatment of venous thromboembolism and the rules of evidence applied. A perspective on the impact of the recommendations is offered.