Subcutaneous heparin does not increase postoperative complications in neurosurgical patients: An institutional experience

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.

Prophylactic Unfractionated Subcutaneous Heparin Does Not Increase Postoperative Hemorrhage in Elderly Patients Undergoing Emergency Neurosurgical Procedures

Purpose

The purpose of this study is to evaluate the impact in the development of intracerebral hemorrhage in elderly critically ill patients who received prophylactic subcutaneous unfractionated heparin (SCUFH) less than 24 hours after undergoing emergency neurosurgery. 

Methods

A retrospective analysis was performed on patients who underwent emergency neurosurgery and were admitted to the surgical intensive care unit (SICU) at a tertiary care center over a 10-year period. Administration of prophylactic SCUFH within 24 hours of neurosurgery was required for inclusion. Demographic and clinical characteristics were recorded. The primary outcome was a rate of postoperative hemorrhagic complications with respect to age.

Results

We identified 223 emergency neurosurgical patients: 100 (45%) patients did not receive prophylactic SCUFH and were excluded. The remaining 123 (55%) patients met all inclusion criteria, of whom 73 (59%) patients were under 65 years old, and 50 (41%) patients were over 65 years old. Patients under 65 years old had significantly lower body mass index (BMI), lower Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, and Simplified Acute Physiology Score (SAPS) scores, and shorter median SICU length of stay compared to patients over 65 years old. No statistically significant difference in the rate of postoperative hemorrhagic or non-hemorrhagic neurological complications was observed between patients in either age group. 

Conclusion

Age over 65 years was not associated with a higher risk of postoperative hemorrhage in patients who received SCUFH after emergency neurosurgery. SCUFH can be safely used as a chemoprophylactic agent against venous thromboembolism for elderly patients when used within 24 hours after emergency neurosurgery. 

Multidisciplinary Bundle Approach in Venous Thromboembolism Prophylaxis in Patients with Non-Traumatic Subarachnoid Hemorrhage

Background

A venous thromboembolism (VTE) bundle was launched in 2016 at the University of Illinois Hospital aiming to reduce the rate of VTE in the neurosurgical ICU. Main elements of the bundle included correct and early use of intermittent pneumatic compression and subcutaneous heparin.

Methods

Patients with SAH were retrospectively identified from 2014 until 2018. VTE events were diagnosed using twice weekly lower-extremity venous Duplex ultrasound and chest computerized tomography when appropriate.

Results

A total of 133 patients was included in each group. The incidence of VTE was not significantly different before and after the bundle (15% vs. 12%, p = 0.47). No difference was found regarding new episode of intracranial hemorrhage secondary to SQH (1.5% vs. 2.1%, p = 0.65). Multivariate analysis demonstrated that longer ICU LOS, higher Caprini score, and presence of baseline lung diseases were associated with VTE development.

Conclusions

With a median Caprini score of 9, our patient population was found to be at high risk for developing VTE. The implementation of the VTE bundle did not significantly reduce the rate of VTE in patients with non-traumatic SAH at UIH.

Pharmacologic thromboprophylaxis in adult patients undergoing neurosurgical interventions for preventing venous thromboembolism

The impact of pharmacologic prophylaxis for venous thromboembolism in patients undergoing neurosurgical intervention remains uncertain. We reviewed the efficacy and safety of pharmacologic compared with nonpharmacologic thromboprophylaxis in neurosurgical patients. Three databases were searched through April 2018, including those for randomized controlled trials (RCTs) and for nonrandomized controlled studies (NRSs). Independent reviewers assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Seven RCTs and 3 NRSs proved eligible. No studies reported on symptomatic proximal and distal deep vein thrombosis (DVT). Two RCTs reported on screening-detected proximal and distal DVTs. We used the findings of these 2 RCTs as the closest surrogate outcomes to inform the proximal and distal DVT outcomes. These 2 RCTs suggest that pharmacologic thromboprophylaxis may decrease the risk of developing asymptomatic proximal DVT (relative risk [RR], 0.50; 95% confidence interval [CI], 0.30-0.84; low certainty). Findings were uncertain for mortality (RR, 1.27; 95% CI, 0.57-2.86; low certainty), symptomatic pulmonary embolism (PE) (RR, 0.84; 95% CI, 0.03-27.42; very low certainty), asymptomatic distal DVT (RR, 0.54; 95% CI, 0.27-1.08; very low certainty), and reoperation (RR, 0.43; 95% CI, 0.06-2.84; very low certainty) outcomes. NRSs also reported uncertain findings for whether pharmacologic prophylaxis affects mortality (RR, 0.72; 95% CI, 0.46-1.13; low certainty) and PE (RR, 0.18; 95% CI, 0.01-3.76). For risk of bleeding, findings were uncertain in both RCTs (RR, 1.57; 95% CI, 0.70-3.50; low certainty) and NRSs (RR, 1.45; 95% CI, 0.30-7.12; very low certainty). In patients undergoing neurosurgical procedures, low certainty of evidence suggests that pharmacologic thromboprophylaxis confers benefit for preventing asymptomatic (screening-detected) proximal DVT with very low certainty regarding its impact on patient-important outcomes.

American Society of Hematology 2019 guidelines for management of venous thromboembolism: prevention of venous thromboembolism in surgical hospitalized patients

BACKGROUND

Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2).

CONCLUSIONS

For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.

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.

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.

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.

What clinical factors predict the incidence of deep venous thrombosis and pulmonary embolism in neurosurgical patients?

Object

Venous thromboembolisms (VTEs) occur frequently in surgical patients and can manifest as pulmonary emboli (PEs) or deep venous thromboses (DVTs). While many medical therapies have been shown to prevent VTEs, neurosurgeons are concerned about the use of anticoagulants in the postoperative setting. To better understand the prevalence of and the patient-level risk factors for VTE, the authors analyzed data from the National Surgical Quality Improvement Program (NSQIP).

Methods

Retrospective data on 1,777,035 patients for the years from 2006 to 2011 were acquired from the American College of Surgeons NSQIP database. Neurosurgical cases were extracted by querying the data for which the surgical specialty was listed as “neurological surgery.” Univariate statistics were calculated using the chi-square test, with 95% confidence intervals used for the resultant risk ratios. Multivariate models were constructed using binary logistic regression with a maximum number of 20 iterations.

Results

Venous thromboembolisms were found in 1.7% of neurosurgical patients, with DVTs roughly twice as common as PEs (1.3% vs 0.6%, respectively). Significant independent predictors included ventilator dependence, immobility (that is, quadriparesis, hemiparesis, or paraparesis), chronic steroid use, and sepsis. The risk of VTE was significantly higher in patients who had undergone cranial procedures (3.4%) than in those who had undergone spinal procedures (1.1%).

Conclusions

Venous thromboembolism is a common complication in neurosurgical patients, and the frequency has not changed appreciably over the past several years. Many factors were identified as independently predictive of VTEs in this population: ventilator dependence, immobility, and malignancy. Less anticipated predictors included chronic steroid use and sepsis. Venous thromboembolisms appear significantly more likely to occur in patients undergoing cranial procedures than in those undergoing spinal procedures. A better appreciation of the prevalence of and the risk factors for VTEs in neurosurgical patients will allow targeting of interventions and a better understanding of which patients are most at risk.

Defining incidence and risk factors of venous thromboemolism after hepatectomy

BACKGROUND

The incidence of venous thromboembolism (VTE) among patients undergoing hepatic surgery is poorly defined, leading to varied use of VTE prophylaxis among surgeons. We sought to define the incidence of VTE after liver surgery and identify risk factors associated with VTE.

METHODS

Incidence of VTE and associated risk factors within 90 days of hepatic resection between 2006 and 2012 at a major academic center was analyzed. Risk factors for VTE were identified using univariate and multivariate analyses.

RESULTS

A total of 599 patients were included in the study cohort; 30 (5.0 %) had a prior history of VTE. The indications for surgery were malignant (90.8 %) and benign lesions (9.2 %). The majority of patients underwent a minor hepatectomy (<3 Couinaud segments; n = 402, 67.1 %) while 195 (32.6 %) patients underwent a major hepatectomy (≥3 Couinaud segments). Three hundred seven (51.3 %) patients were started on VTE chemoprophylaxis preoperatively with 407 (67.8 %) patients receiving VTE chemoprophylaxis within 24 h of surgery. Twenty-eight (4.7 %) patients developed VTE; 20 (3.3 %) had deep venous thrombosis (DVT), 11 (1.8 %) had pulmonary embolism (PE), and three (0.5 %) developed both DVT and PE. Among the VTE patients, 23 (82.1 %) had received VTE chemoprophylaxis. On multivariate analyses, history of VTE (odds ratio [OR] 4.51, 95 % confidence interval [CI] 1.81-17.22, P = 0.03), prolonged operative time (OR 1.17 per additional hour, 95 % CI 1.04-1.32, P = 0.009), and increased length of stay (LOS) (OR 1.07, 95 % CI 1.02-1.12, P = 0.01) were independent risk factors for VTE.

CONCLUSION

VTE within 90 days of hepatic resection is common, occurring in nearly one in 20 patients. Most VTE events occurred among patients who received current best practice prophylaxis for VTE. More aggressive strategies to identify and reduce the risk of VTE in patients at highest risk of VTE, including those with a history of VTE, extended operative time, and prolonged LOS, are warranted.