Attitudes to the use of prophylaxis for thrombo-embolism in neurosurgical patients

Venous thromboembolism in aneurysmal subarachnoid hemorrhage: Risk factors and timing of chemoprophylaxis

INTRODUCTION

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality among patients recovering from aneurysmal subarachnoid hemorrhage (aSAH). Prophylactic heparin reduces the risk of VTE, but the optimal timing for its initiation among aSAH patients remains unclear.

OBJECTIVE

To conduct a retrospective study assessing risk factors for VTE and optimal timing of chemoprophylaxis in patients treated for aSAH.

METHODS

From 2016-2020, 194 adult patients were treated for aSAH at our institution. Patient demographics, clinical diagnoses, complications, pharmacologic interventions, and outcomes were recorded. Risk factors for symptomatic VTE (sVTE) were analyzed via Chi-squared, univariate, and multivariate regression.

RESULTS

In total 33 patients presented with sVTE (25 DVT, 14 PE). Patients with sVTE had longer hospital stays (p < 0.01) and worse outcomes at one-month (p < 0.01) and three-month follow-up (p = 0.02). Univariate predictors of sVTE included male sex (p = 0.03), Hunt Hess score (p = 0.01), Glasgow Coma scale (p = 0.02), intracranial hemorrhage (p = 0.03), hydrocephalus requiring external ventricular drain (EVD) placement (p < 0.01), and mechanical ventilation (p < 0.01). Only hydrocephalus requiring EVD (p = 0.01) and ventilator use (p = 0.02) remained significant upon multivariate analysis. Patients with delayed heparin introduction were significantly more likely to sustain sVTE on univariate analysis (p = 0.02) with a trend-level significance on multivariate analysis (p = 0.07).

CONCLUSIONS

Patients with aSAH are more likely to develop sVTE following use of perioperative EVD or mechanical ventilation. sVTE leads to longer hospital stays and worse outcomes among patients treated for aSAH. Delayed heparin initiation increases the risk of sVTE. Our results may help guide surgical decision-making during recovery from aSAH and improve VTE-related postoperative outcomes.

What Is the Safety and Efficacy of Chemical Venous Thromboembolism Prophylaxis Following Vestibular Schwannoma Surgery?

OBJECTIVE

The benefit of routine chemical prophylaxis use for venous thromboembolism (VTE) prevention in skull base surgery is controversial. Chemical prophylaxis can prevent undue morbidity and mortality, however there are risks for hemorrhagic complications.

STUDY DESIGN

Retrospective case-control.

METHODS

A retrospective chart review of patients who underwent surgery for vestibular schwannoma from 2011 to 2016 was performed. Patients were divided by receipt of chemical VTE prophylaxis. Number of VTEs and hemorrhagic complications (intracranial hemorrhage, abdominal hematoma, and postauricular hematoma) were recorded.

RESULTS

One hundred twenty-six patients were identified, 55 received chemical prophylaxis, and 71 did not. All the patients received mechanical prophylaxis. Two patients developed a deep vein thrombosis (DVT) and one patient developed a pulmonary embolism (PE). All patients who developed a DVT or PE received chemical prophylaxis. There was no difference in DVT (p = 0.1886) or PE (p = 0.4365) between those who received chemical prophylaxis and those who did not. Five patients developed a hemorrhagic complication, two intracranial hemorrhage, three abdominal hematoma, and zero postauricular hematoma. All five patients with a complication received chemical prophylaxis (p = 0.00142). The relative risk of a hemorrhagic complication was 14.14 (95% CI = 0.7987-250.4307; p = 0.0778).

CONCLUSION

There was a significant difference between the number of hemorrhagic complications but not between numbers of DVT or PE. Mechanical and chemical prophylaxis may lower the risk of VTE but in our series, hemorrhagic complications were observed. These measures should be used selectively in conjunction with early ambulation.

Low-Dose versus Therapeutic Range Intravenous Unfractionated Heparin Prophylaxis in the Treatment of Patients with Severe Aneurysmal Subarachnoid Hemorrhage After Aneurysm Occlusion

BACKGROUND

While prophylaxis with intravenous unfractionated heparin (UFH) can effectively prevent venous thromboembolism (VTE) during the neurocritical care of patients with severe aneurysmal subarachnoid hemorrhage (aSAH), the risk for intracranial bleeding complications might increase. Owing to this therapeutic dilemma, the UFH administration regimen in this critical patient population remains highly controversial.

METHODS

We performed a retrospective analysis of patients with severe aSAH (Fisher grade 3-4) receiving either low-dose (activated partial thromboplastin time [aPTT] <40 seconds) or therapeutic range (aPTT 50-60 seconds) UFH during intensive care unit (ICU) treatment after complete surgical/endovascular aneurysm occlusion. The primary outcome was the rate of bleeding/VTE complications and the investigation of potential risk factors.

RESULTS

This study series comprised 410 patients with aneurysmal SAH (aSAH), with a mean age of 54.7 ± 12.6 years, a male:female ratio of 1:2.2, and aSAH-associated intracerebral hemorrhage (ICH) in 33.2%. After complete aneurysm occlusion, 112 patients (27.3%) received therapeutic dose UFH and 298 patients (72.7%) received low-dose UFH. VTE events occurred in 5.4% of the low-dose UFH cohort and in 6.3% of the therapeutic dose UFH cohort, with no significant differences in the rate and severity of VTE events. However, an increase in initial SAH-associated ICH was significantly (P = 0.007) more frequent in the therapeutic dose cohort (18.8% vs. 3.4%). Heparin-induced thrombocytopenia (HIT) was the sole risk factor for VTE (P < 0.001), and both an aPTT ≥50 seconds under UFH administration (P = 0.007) and the initial presence of SAH-associated ICH (P = 0.035) were significant risk factors for intracranial bleeding complications.

CONCLUSIONS

Even in high-risk neurocritical patients with severe SAH and prolonged ICU treatment, low-dose UFH-administration for VTE prophylaxis is equally effective as therapeutic UFH administration and carries a lower risk of bleeding complications.

[Posttraumatic thromboembolic complications: Incidence, risk factors, pathophysiology and prevention]

Venous thromboembolism (VTE) remains a major challenge in critically ill patients. Subjects admitted in intensive care unit (ICU), in particular trauma patients, are at high-risk for both deep vein thrombosis (DVT) and pulmonary embolism (PE). The rate of symptomatic PE in injured patients has been reported previously ranging from 1 to 6%. The high incidence of posttraumatic venous thromboembolic events is well known. In fact, major trauma is a hypercoagulable state. Several factors placing the individual patient at a higher risk for the development of DVT and PE have been suggested: high ISS score, meningeal hemorrhage and spinal cord injuries have frequently been reported as a significant risk factor for VTEs after trauma. Posttraumatic pulmonary embolism traditionally occurs after a period of at least 5 days from trauma. The prevention can reduce the incidence and mortality associated with the pulmonary embolism if it is effective. There is no consensus is now available about the prevention of venous thromboembolism in trauma patients.

The Use of Intermittent Pneumatic Compression in Orthopedic and Neurosurgical Postoperative Patients: A Systematic Review and Meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis was to carry out an up-to-date evaluation on the use of compression devices as deep vein thrombosis (DVT) prophylaxis methods in orthopedic and neurological patients.

SUMMARY OF BACKGROUND DATA

There is an increased risk of DVT with surgery, particularly in patients who are not expected to mobilize soon after their procedures, such as orthopedic and neurosurgical patients. Compression devices are often employed for DVT prophylaxis in these patients. However, the true efficacy of these devices and the standardization of use with these devices are yet to be established.

METHODS

Medline, CINAHL, Embase, Google Scholar, and the Cochrane library electronic databases were searched to identify randomized controlled trials and observational studies reporting on the use of compression devices for DVT prevention.

RESULTS

Nine studies were included for review and meta-analysis. Use of an intermittent pneumatic compression device alone is neither superior nor inferior to chemoprophylaxis.

CONCLUSIONS

In the absence of large randomized multicenter trials comparing the use of intermittent pneumatic compression or chemoprophylaxis alone to a combination of both treatments, the current evidence supports the use of a combined approach in high-risk surgical patients.

Safety of early pharmacological thromboprophylaxis after subarachnoid hemorrhage

OBJECTIVE

The recent guidelines on management of aneurysmal subarachnoid hemorrhage (aSAH) advise pharmacological thromboprophylaxis (PTP) after aneurysm obliteration. However, no study has addressed the safety of PTP in the aSAH population. Therefore, the aim of this study was to assess the safety of early PTP after aSAH.

METHODS

Retrospective cohort of aSAH patients admitted between January 2012 and June 2013 in a single high-volume aSAH center. Traumatic SAH and perimesencephalic hemorrhage patients were excluded. Patients were grouped according to PTP timing: early PTP group (PTP within 24 hours of aneurysm treatment), and delayed PTP group (PTP started > 24 hours).

RESULTS

A total of 174 SAH patients (mean age 56.3±12.5 years) were admitted during the study period. Thirty-nine patients (22%) did not receive PTP, whereas 135 patients (78%) received PTP after aneurysm treatment or negative angiography. Among the patients who received PTP, 65 (48%) had an external ventricular drain. Twenty-eight patients (21%) received early PTP, and 107 (79%) received delayed PTP. No patient in the early treatment group and three patients in the delayed PTP group developed an intracerebral hemorrhagic complication. Two required neurosurgical intervention and one died. These three patients were on concomitant PTP and dual antiplatelet therapy.

CONCLUSIONS

The initiation of PTP within 24 hours may be safe after the treatment of a ruptured aneurysm or in angiogram-negative SAH patients with diffuse aneurysmal hemorrhage pattern. We suggest caution with concomitant use of PTP and dual antiplatelet agents, because it possibly increases the risk for intracerebral hemorrhage.

Screening strategy using sequential serum D-dimer assay for the detection and prevention of venous thromboembolism after elective brain tumor surgery

OBJECTIVE

Venous thromboembolism (VTE) is a life-threatening complication in neurosurgical patients. This study retrospectively analyzed the effectiveness and safety of a screening strategy for the detection and prevention of VTE in patients undergoing elective brain tumor surgery.

PATIENTS

A total of 419 consecutive patients who underwent brain tumor surgery during 5 years were enrolled. At the midpoint of the study period, screening for VTE was introduced based on measurement of serum D-dimer level on the day after surgery and then once or twice every week. Anticoagulant therapy was started after the diagnosis of VTE. The two groups with (228 patients) and without (191 patients) screening were compared.

RESULTS

Most of the demographic and clinical characteristics were relatively well balanced in the groups. VTE was diagnosed in 23 (5.5%) patients overall; the rate was higher in the screening group (7.0%) than in the non-screening group (3.7%). Although the rate of VTE-related adverse events was lower in the screening group (1.3% vs. 2.6%), the rate of hemorrhagic complications was higher (2.2% vs. 0.5%). Multivariate analysis indicated that malignant histology and preoperative paresis were independent risk factors for the diagnosis of VTE.

CONCLUSIONS

Many VTE patients may not exhibit signs or symptoms, so screening using surrogate markers for VTE (D-dimer) may be useful in the early detection of asymptomatic VTE. However, most distal, deep venous thrombosis in isolation is not life-threatening, so the added efficacy of anticoagulant agents at this stage has to be weighed against the risks of hemorrhagic complications, especially in the early postoperative period.

Chest physicians' knowledge of appropriate thromboprophylaxis: insights from the PROMOTE study

Venous thromboembolism (VTE) is a major cause of in-hospital mortality. Several international guidelines provide thromboprophylaxis recommendations; however, guidelines adherence is missing worldwide. We evaluated the chest physicians' knowledge regarding VTE prophylaxis, using a systematically developed questionnaire. The Prophylaxis-foR-venOus-throMbOembolism-assessmenT-questionnairE (PROMOTE) questionnaire was developed using an algorithm encompassing the most important VTE prophylaxis topics and included 13 clinical scenarios. Responses were evaluated with reference to the eighth edition of American College of Chest Physicians guidelines for VTE prevention to assess thromboprophylaxis appropriateness. The questionnaires were distributed during the fourth International Congress on Pulmonary Disease, Intensive Care and Tuberculosis. From the 88 received questionnaires (response rate: 39.8%), 82 were acceptable (62 men, 20 women). The most commonly cited VTE risk factors were immobility (79.2%), surgery (68.2%), and cancer (60.9%). The mean correct response ratio to the questions was 67% [95% confidence interval (CI) 64-70%] with highest appropriateness ratios amongst cardiologists (77.1 ± 5.8%) and lowest ratios among thoracic surgeons (59.2 ± 5%). Physicians' specialty had a significant effect on the overall appropriateness (P = 0.04) and most of appropriateness subcategories. Thoracic surgeons had the lowest rate of over-prophylaxis (P = 0.02). Years passed from graduation were inversely associated with overall appropriateness (P = 0.006). Physicians with academic engagements had a higher overall appropriateness (P = 0.04). We found a wide gap between the guideline recommendations and the responses. PROMOTE is the first systematically developed questionnaire that addresses chest physicians' thromboprophylaxis knowledge and could be useful to strategies to improve VTE prophylaxis. Because of the dissimilar prophylaxis pitfalls of different specialists, distinct educational programs seem necessary to improve their knowledge of proper VTE prophylaxis.

Randomized controlled trial of a new portable calf compression device (Venowave) for prevention of venous thrombosis in high-risk neurosurgical patients

BACKGROUND

Patients undergoing neurosurgical procedures are at risk of venous thromboembolism (VTE), but often have contraindications for anticoagulant prophylaxis.

OBJECTIVES

To assess the efficacy and tolerability of a new, lightweight, portable, battery-powered, intermittent calf compression device, Venowave, for the prevention of VTE in neurosurgical inpatients.

PATIENTS/METHODS

We performed an open randomized controlled trial comparing Venowave with control for the prevention of VTE in patients undergoing neurosurgery. The primary outcome was the composite of asymptomatic deep vein thrombosis (DVT) detected by screening venography or compression ultrasound performed on day 9 (± 2 days) and symptomatic VTE.

RESULTS

We randomized 75 patients to receive Venowave devices and 75 to the control group. All patients were prescribed graduated compression stockings and physiotherapy. VTE occurred in three patients randomized to Venowave and in 14 patients randomized to control (4.0% vs. 18.7%, relative risk 0.21; 95% confidence interval 0.05-0.75, P = 0.008). Similar reductions were seen for proximal DVT (2.7% vs. 8.0%) and symptomatic VTE (0% vs. 2.7%), and the results were consistent in all subgroups examined.

CONCLUSIONS

Venowave devices are effective in preventing VTE in high-risk neurosurgical patients.

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.

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.

An evaluation of practice pattern for venous thromboembolism prevention in Lebanese hospitals

BACKGROUND

Venous thromboembolism (VTE) is a major cause of death among hospitalized patients. Many VTE prophylaxis guidelines have been developed, including the American College of Chest Physicians (ACCP). VTE prophylaxis is required in specific patients; however, its practice is not always optimal, and often depends on the hospitals' protocols. In Lebanon, information about the appropriateness of VTE prophylaxis in health care centers is lacking.

OBJECTIVE

The primary objective of this study was to evaluate the pattern of VTE prophylaxis application, including agents, doses, duration of treatment, and route of administration, in Lebanese health care centers.

METHODS

A Lebanese multi-center, prospective, chart review study was conducted over 4 months. Data on demographics, VTE prophylaxis medication, dose, route, duration, and associated risk factors were collected by pharmacy students. The appropriateness of VTE prophylaxis was determined as per ACCP guidelines. Patients receiving VTE treatment were excluded from the study. Institutional review board (IRB) approval was obtained from each hospital center.

RESULTS

A total of 840 patients were included. Both gender groups were equally represented in the sample and the mean age was 59 +/- 19.53 years. The majority (639/840, 76.1%) of the sample were at high risk for deep venous thrombosis (DVT), and inappropriate VTE prophylaxis was reported in 35% of the low-risk group, in 70% of the moderate-risk group, and in 39% of the high-risk group (P < 0.0001). Comparing proper VTE prophylaxis practice between intensive care unit (ICU) and non-ICU patients, there was no statistical difference observed in teaching hospitals (67.2% vs. 65.5%, P = 0.312). However, in non-teaching hospitals, appropriate VTE prophylaxis practice was more prevalent in ICU than non-ICU patients (65.9% vs. 51.2%, P = 0.004). The average duration of VTE prophylaxis was less than 10 days. Missing data was a major limitation for this study, where, for instance, the duration of prophylaxis could not be accurately abstracted in half of the sample. Another limitation was the absence of laboratory results needed for clinical assessment of the regimen used.

CONCLUSION

This study reflected the importance of assessing VTE prophylaxis in Lebanese hospitals, thus, the need for implementing established guidelines to improve the overall patient safety.

Prophylaxis against thromboembolism in spinal surgery

Thromboprophylaxis in spinal surgery is a controversial topic. In the current environment of risk management, it seems reasonable to review and critically appraise the risks and benefits of different prophylaxis methods in spinal surgery.

Medical management of patients with brain tumors

The most common medical problems in brain tumor patients include the management of seizures, peritumoral edema, medication side effects, venous thromboembolism (VTE), fatigue and cognitive dysfunction. Despite their importance, there are relatively few studies specifically addressing these issues. There is increasing evidence that brain tumor patients who have not had a seizure do not benefit from prophylactic antiepileptic medications. Patients on corticosteroids are at greater risk of Pneumocystis jerovecii pneumonia and may benefit from prophylactic therapy. There is also growing evidence suggesting that anticoagulation may be more effective than inferior vena cava IVC) filtration devices for treating VTE in brain tumor patients and the risk of hemorrhage with anticoagulation is relatively small. Low-molecular weight heparin may be more effective than coumadin. Medications such as modafinil and methylphenidate have assumed an increasing role in the treatment of fatigue, while donepezil and memantine may be helpful with memory loss.

Efficacy of Pneumatic Compression Stocking Prophylaxis in the Prevention of Deep Venous Thrombosis and Pulmonary Embolism Following 139 Lumbar Laminectomies With Instrumented Fusions

OBJECTIVE

Low-dose heparin (LDH) regimens reduce the frequency of deep venous thrombosis (DVT) and pulmonary embolism (PE) in spinal surgery but pose a risk of postoperative hemorrhage threatening neurologic function. Pneumatic compression stocking (CS) could provide an alternative means of mechanical prophylaxis alone against DVT and PE and would possibly avoid its hemorrhagic complications.

METHODS

The efficacy of CS alone in preventing DVT and PE was evaluated in 139 patients undergoing multilevel lumbar laminectomies (average 3.8 levels) with instrumented fusions (average 1.4 levels). All patients received CS stocking prophylaxis intraoperatively and throughout the average 5-day postoperative course including following ambulation. Doppler screening for DVT was routinely performed 2 days postoperatively. Subsequent Doppler studies or computed tomography angiograms were selectively performed in symptomatic patients with potential DVT/PE.

RESULTS

Four (2.8%) patients developed DVT 2-6 days postoperatively and required inferior vena cava (IVC) filters. One of the four had a positive routine screening Doppler study performed the second postoperative day. Two developed DVT the fourth postoperative day. The fourth patient developed DVT 6 days postoperatively but 3 weeks later embolized around the IVC filter. This patient, the only one to develop a PE, tested positive for Factor V Leiden mutation (hypercoagulable syndrome) and remains on long-term warfarin.

CONCLUSIONS

Pneumatic compression stocking prophylaxis effectively reduced the incidence of DVT (2.8%) and PE (0.7%) in 139 patients undergoing multilevel lumbar laminectomies with instrumented fusions. These rates compared favorably with those reported in spinal series employing LDH prophylaxis.

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.

The efficacy of a new portable sequential compression device (SCD Express) in preventing venous stasis

OBJECTIVE

It has been previously shown that the SCD Response Compression System, by sensing the postcompression refill time of the lower limbs, delivers more compression cycles over time, resulting in as much as a 76% increase in the total volume of blood expelled per hour. Extended indications for pneumatic compression have necessitated the introduction of portable devices. The aim of our study was to test the hemodynamic effectiveness of a new portable sequential compression system (the SCD Express), which has the ability to detect the individual refill time of the two lower limbs separately.

METHODS

This was an open, controlled trial with 30 normal volunteers. The new SCD Express was compared with the SCD Response Compression System in the supine and semirecumbent positions. The refilling time sensed by the device was compared with that determined from velocity recordings of the superficial femoral vein using duplex ultrasonography. Baseline and augmented flow velocity and volume flow, including the total volume of blood expelled per hour during compression with the SCD Express, were compared with those produced by the SCD Response compression system in the same volunteers and positions.

RESULTS

Both devices significantly increased venous flow velocity as much as 2.26 times baseline in supine position and 2.67 times baseline in semirecumbent position (all P < .001). There was a linear relationship between duplex ultrasonography-derived refill time and the SCD Express-derived refill time in both the supine (r = 0.39, P = .03) and semirecumbent (r = 0.71, P < .001) positions but not with the SCD Response. Refill time measured by the SCD Express device was significantly shorter and the cycle rate higher in comparison with the SCD Response in both positions. The single-cycle flow velocity and volume flow parameters generated by the two devices were similar in both positions. However, median (interquartile range) total volume of blood expelled per hour was slightly higher with the SCD Express device in the supine position (7206 mL/h [range, 5042-8437] vs 6712 mL/h [4941-10,676]; P = .85) and semirecumbent position (4588 mL/h [range, 3721-6252] vs 4262 mL/h [3520-5831]; P = .22). Peak volume of blood expelled per hour by the SCD Express device in the semirecumbent position was significantly increased by 10% in comparison with the SCD Response (P = .03).

CONCLUSIONS

Flow velocity and volume flow enhancement by the SCD Response and SCD Express were essentially similar. The latter, a portable device with optional battery power that detects the individual refill time of the lower limbs separately, is anticipated to be associated with improved overall compliance and therefore optimized thromboprophylaxis. Studies testing its potential for improved efficacy in preventing deep vein thrombosis are justified.

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.

Efficacy of mechanical prophylaxis for venous thromboembolism in patients with brain tumors

Patients with brain tumors are at considerable risk for the formation of venous thromboemboli. One method of preventing these complications is mechanical prophylaxis in which an external pneumatic compression device and graduated elastic compression stockings are used. Evidence indicates that these devices prevent deep venous thrombosis (DVT) and pulmonary embolism (PE) by limiting venous stasis and increasing fibrinolytic activity at both the local and systemic levels. The authors present evidence for the occurrence of both mechanisms and discuss the use of mechanical compression in the setting of surgery for brain tumors. They also present data proving the efficacy of these devices in patients who undergo craniotomy with motor mapping for resection of glioma and in whom the contralateral leg receives no prophylaxis. Finally, they comment on the use of anticoagulation therapy both in addition to and in place of mechanical prophylaxis.