Abnormal coagulation profile in brain tumor patients during surgery

Perioperative Hypercoagulability in Free Flap Reconstructions Performed for Intracranial Tumors

OBJECTIVE(S)

Patients with intracranial tumors have a higher risk of thromboembolic events. This risk increases at the time of surgical intervention. We have noted an anecdotal increase in perioperative flap thrombosis in patients undergoing free tissue transfer for intracranial tumor resection. This study aims to formally evaluate this risk.

METHODS

A multi-institutional retrospective chart review was performed of patients who underwent free tissue transfer for scalp/cranial reconstruction. Perioperative thrombosis and free flap outcomes were evaluated.

RESULTS

The 209 patients who underwent 246 free tissue transfers were included in the study. The 28 free flap scalp reconstructions were associated with intracranial tumors, 19 were performed following composite cranial resections with associated dural resection/reconstruction, and 199 were performed in the absence of intracranial tumors (control group). There was a significantly higher incidence of perioperative flap thrombosis in the intracranial tumor group (11/28, 39%) when compared to controls (38/199, 19%) (p = 0.0287). This was not seen when scalp tumors extended to the dura alone (4/19, 21%, p = 0.83). Therapeutic anticoagulation used for perioperative thrombosis (defined as intraoperative or in the immediate postoperative phase up to 5 days) was associated with a lower risk of flap failure, although this was not statistically significant (p = 0.148). Flap survival rates were equivalent between flaps performed for intracranial pathology (93.3%) and controls (95%).

CONCLUSION

There is an increase in perioperative flap thrombosis in patients with intracranial tumors undergoing free tissue scalp reconstruction. Anticoagulation appears to mitigate this risk.

LEVEL OF EVIDENCE

This recommendation is based on level 3 evidence (retrospective case-control studies, systematic review of retrospective studies, and case reports) Laryngoscope, 2022.

Predictors of Venous Thromboembolism After Nonemergent Craniotomy: A Nationwide Readmission Database Analysis

BACKGROUND

Venous thromboembolism (VTE) is responsible for many hospital readmissions each year, particularly among postsurgical cohorts. Because early and indiscriminate VTE prophylaxis carries catastrophic consequences in postcraniotomy cohorts, identifying factors associated with a high risk for thromboembolic complications is important for guiding postoperative management.

OBJECTIVE

To determine VTE incidence in patients undergoing nonemergent craniotomy and to evaluate for factors that predict 30-day and 90-day readmission with VTE.

METHODS

The 2010-2014 cohorts of the Nationwide Readmissions Database were used to generate a large heterogeneous craniotomy sample.

RESULTS

There were 89,450 nonemergent craniotomies that met inclusion criteria. Within 30 days, 1513 patients (1.69%) were readmitted with VTE diagnoses; among them, 678 (44.8%) had a diagnosis of deep vein thrombosis alone, 450 (29.7%) had pulmonary embolism alone, and 385 (25.4%) had both. The corresponding 30-day deep vein thrombosis and pulmonary embolism incidences were 1.19% and 0.93%, respectively. In multivariate analysis, several factors were significantly associated with VTE readmission, namely, craniotomy for tumor, corticosteroids, advanced age, greater length of stay, and discharge to institutional care.

CONCLUSIONS

Craniotomies for tumor, corticosteroids, advanced age, prolonged length of stay, and discharge to institutional care are significant predictors of VTE readmission. The implication of steroids, coupled with their ubiquity in neurosurgery, makes them a potentially modifiable risk factor and a prime target for VTE reduction in craniotomy cohorts. Furthermore, the fact that dose is proportional to VTE risk in the literature suggests that careful consideration should be given toward decreasing regimens in situations in which use of a lower dose might prove equally sufficient.

Gastrointestinal stromal tumors: Fibrinogen levels are associated with prognosis of patients as blood-based biomarker

Improved prediction of prognosis for primary gastrointestinal stromal tumors (GISTs) after curative resection is an important goal in clinical practice. Coagulation factor of fibrinogen may inform prognosis of tumor patients as blood-based biomarker. Here, we aimed to analyze the prognostic value of fibrinogen levels in patients with GIST and to explore potential threshold of fibrinogen on postoperative clinical outcome.A retrospective study was performed including data from 91 patients with newly diagnosed GISTs who underwent curative resection. Patients were followed-up for a median period of 2 years. Cox regression and competing risk analysis were applied to study the association between fibrinogen and risk of death or recurrence. Smoothing plot and threshold effect analysis were applied to learn the relationship further and explore potential threshold.High levels of fibrinogen are associated with decreased overall survival (OS) and recurrence free survival (RFS) in patients with GISTs. We discovered a nonlinear relationship between levels of fibrinogen and the risk of death or recurrence. Further, we detected a threshold for fibrinogen (3.7 g/L) on the prognosis of GISTs patients. When fibrinogen was above the inflection point, the increase in fibrinogen levels was strongly associated with increase in the risk of death or recurrence.Elevated fibrinogen can serve as an independent prognostic biomarker for a worse clinical outcome in GIST patients.

Severity of anemia and hemostatic parameters are strong predictors of outcome in postoperative neurosurgical patients

Objective:

Post-operative neurosurgical patients are commonly associated with haemostatic derangements; many a times leading to development of overt disseminated intravascular coagulation (DIC) and eventually death in some of them. The present study has analysed the factors that would predict the outcome in post operative neurosurgical patients with deranged haemostatic parameters.

Methods:

This is a prospective, descriptive study over a period of 15 months on 115 post operative neurosurgical patients who were clinically suspected to have DIC and investigated for the haemostatic parameters. Patients with at least one parameter abnormal were included in the study and complete data was available in 85 patients was analysed.

Results:

Majority of deaths (22/33, 66.7%) were related to bleeding and end organ failure attributed to DIC. The most common haemostatic abnormalities found were thrombocytopenia with prolonged Prothrombin time (PT) in 48/115 (42.7%) patients. The parameters found significantly different between those who survived and those died were age, post-operative development of chest infections, severe anemia, and renal function abnormalities. Also, patient outcome correlated strongly with marked prolongation of prothrombin time (PT) and Partial thromboplastin time (PTT). However, presence of ≥3 coagulation abnormalities, presence of significant drop in haemoglobin post operatively and /or development of chest infection predicted death in postoperative neurosurgical patients with accuracy of 80.4% and this was highly significant (P = 0.000).

Conclusion:

Presence of ≥3 coagulation abnormalities, significant drop in hemoglobin post operatively and /or development of chest infection post-operatively were strong predictors of death in postoperative neurosurgical patients.

Coagulation during elective neurosurgery with hydroxyethyl starch fluid therapy: an observational study with thromboelastometry, fibrinogen and factor XIII

BACKGROUND

Several studies have described hypercoagulability in neurosurgery with craniotomy for brain tumor resection. In this study, hydroxyethyl starch (HES) 130/0.42 was used for hemodynamic stabilization and initial blood loss replacement. HES can induce coagulopathy with thromboelastographic signs of decreased clot strength. The aim of this study was to prospectively describe perioperative changes in coagulation during elective craniotomy for brain tumor resection with the present fluid regimen.

METHODS

Forty patients were included. Perioperative whole-blood samples were collected for EXTEM and FIBTEM assays on rotational thromboelastometry (ROTEM) and plasma fibrinogen analysis immediately before surgery, after 1 L of HES infusion, at the end of surgery and in the morning after surgery. Factor (F)XIII activity, thrombin-antithrombin complex (TAT) and plasmin-α2-antiplasmin complex (PAP) were analysed in the 25 patients receiving ≥1 L of HES.

RESULTS

Most patients (37 of 40) received HES infusion (0.5-2 L) during surgery. Preoperative ROTEM clot formation/structure, plasma fibrinogen and FXIII levels were generally within normal range but approached a hypocoagulant state during and at end of surgery. ROTEM variables and fibrinogen levels, but not FXIII, returned to baseline levels in the morning after surgery. Low perioperative fibrinogen levels were common. TAT levels were increased during and after surgery. PAP levels mostly remained within the reference ranges, not indicating excessive fibrinolysis. There were no differences in ROTEM results and fibrinogen levels in patients receiving <1 L HES and ≥1 L HES.

CONCLUSIONS

Only the increased TAT levels indicated an intra- and postoperative activation of coagulation. On the contrary, all other variables deteriorated towards hypocoagulation but were mainly normalized in the morning after surgery. Although this might be an effect of colloid-induced coagulopathy, we found no dose-dependent effect of HES. The unactivated fibrinolysis indicates that prophylactic use of tranexamic acid does not seem warranted under normal circumstances in elective neurosurgery. Individualized fluid therapy and coagulation factor substitution is of interest for future studies.

Deep venous thrombosis and pulmonary embolisms in adult patients undergoing craniotomy for brain tumors

OBJECTIVE

The development of venothromboembolisms (VTEs), including deep vein thrombosis (DVT) and pulmonary emboli (PE), is common in brain tumor patients. Their development can be catastrophic. Studies evaluating pre-operative clinical factors that predispose patients to the development of VTE are few and limited. An understanding may help risk stratify patients and guide subsequent therapy aimed at reducing the risk of DVTs/PEs.

METHODS

All adult patients who underwent surgery for an intracranial tumor at an academic tertiary care institution between 1998 and 2008 were retrospectively reviewed. Stepwise multivariate logistical regression analysis was used to identify pre-operative factors associated with the development of peri-operative (within 30 days of surgery) DVTs/PEs among patients who underwent surgery of their intracranial tumor.

RESULTS

Of the 4293 patients in this study, 126 (3%) patients developed DVT and/or PE in the peri-operative period. The pre-operative factors independently associated with the development of DVTs/PEs were: poorer Karnofsky performance scale (KPS) [odds ratio (OR), 1·040; 95% confidence interval (CI), 1·026-1·052; P<0·0001], high grade glioma (OR, 1·702; 95% CI, 1·176-2·465; P = 0·005), older age (OR, 1·033; 95% CI, 1·020-1·046; P<0·0001), hypertension (OR, 1·785; 95% CI, 1·180-2·699; P = 0·006), and motor deficit (OR, 1·854; 95% CI, 1·244-2·763; P = 0·002). Eighty six per cent of the patients with DVTs/PEs were treated with either unfractionated or low molecular weight heparin, and 4% of these patients developed intracranial hemorrhage.

DISCUSSION

The present study found that poorer functional status, older age, pre-operative motor deficit, high grade glioma, and hypertension each independently increased the risk of developing peri-operative DVTs/PEs. These findings may provide patients and physicians with prognostic information that may guide therapies aimed at minimizing the development of peri-operative DVTs/PEs.

Clinical use of the low-molecular-weight heparins in cancer patients: focus on the improved patient outcomes

Patients with malignant neoplastic diseases represent a high-risk population relative to thromboembolic disease. With the advent of improved and accessible diagnostic technology, for example, ultrasound and/or spiral CT scans, timely diagnosis of venous thromboembolic events (VTE) is readily accomplished. The introduction of low-molecular-weight heparin (LMWH) approximately two decades ago (in contrast to unfractionated heparin and vitamin K antagonists) has provided a class of agents with a favorable therapeutic index. In the review to follow, the literature regarding the use of LMWH in oncologic patient populations is summarized. Topics addressed include prophylaxis, and treatment as well as consideration of the potential anti-neoplastic properties of this class of drugs.

Venous thromboembolism in malignant gliomas

Malignant gliomas are associated with a very high risk of venous thromboembolism (VTE). While many clinical risk factors have previously been described in brain tumor patients, the risk of VTE associated with newer anti-angiogenic therapies such as bevacizumab in these patients remains unclear. When VTE occurs in this patient population, concern regarding the potential for intracranial hemorrhage complicates management decisions regarding anticoagulation, and these patients have a worse prognosis than their VTE-free counterparts. Risk stratification models identifying patients at high risk of developing VTE along with predictive plasma biomarkers may guide the selection of eligible patients for primary prevention with pharmacologic thromboprophylaxis. Recent studies exploring disordered coagulation, such as increased expression of tissue factor (TF), and tumorigenic molecular signaling may help to explain the increased risk of VTE in patients with malignant gliomas.

Impact of venous thromboembolism and anticoagulation on cancer and cancer survival

Changes in the hemostatic system and chronic hemostatic activation are frequently observed in patients with cancer, even in the absence of venous thromboembolism (VTE). VTE is a leading cause of death among patients with cancer and contributes to long-term mortality in patients with early as well as advanced-stage cancer. Mounting evidence suggests that components of the clotting cascade and associated vascular factors play an integral part in tumor progression, invasion, angiogenesis, and metastasis formation. Furthermore, there are intriguing in vitro and animal findings that anticoagulants, in particular the low molecular weight heparins (LMWHs), exert an antineoplastic effect through multiple mechanisms, including interference with tumor cell adhesion, invasion, metastasis formation, angiogenesis, and the immune system. Several relatively small randomized controlled clinical trials of anticoagulation as cancer therapy in patients without a VTE diagnosis have been completed. These comprise studies with LMWH, unfractionated heparin, and vitamin K antagonists, with overall encouraging but nonconclusive results and some limitations. Meta-analyses performed for the American Society of Clinical Oncology VTE Guidelines Committee and the Cochrane Collaboration suggest overall favorable effects of anticoagulation on survival of patients with cancer, mainly with LMWH. However, definitive clinical trials have been elusive and questions remain regarding the importance of tumor type and stage on treatment efficacy, the impact of fatal thromboembolic events, optimal anticoagulation therapy, and safety with differing chemotherapy regimens. Although the LMWHs and related agents hold promise for improving outcomes in patients with cancer, additional studies of their efficacy and safety in this setting are needed.

Effect of dalteparin and radiation on survival and thromboembolic events in glioblastoma multiforme: a phase II ECOG trial

Laboratory and clinical studies support the concept that heparins, particularly the low molecular component, may serve as an inhibitor of angiogenesis, providing anti-neoplastic effects. Further, treatment with low molecular weight heparin (LMWH) may provide prophylaxis for thromboembolic events (TEE), in glioblastoma (GBM) patients. Dalteparin (5,000 U sub-Q daily) was given with and after conventional radiotherapy to newly diagnosed GBM patients. Forty-five patients were accrued between 5/02 and 9/04; 3 were ineligible. At time of progression, patients could continue dalteparin in addition to standard regimens. Pretreatment characteristics included: median age 61 (range 26-78); ECOG Performance status: 0 = 38%, 1 = 57%, 2 = 5%; gross total resection 45%. There were no grade 3/4 bleeding or thrombocytopenic events, and no TEE occurred while on dalteparin. Median time on dalteparin was 6.3 months, median time to progression was 3.9 months; median survival was 11.9 months. There was no significant improvement in survival when compared to the RTOG GBM database (with various radiation/drug doublets including BCNU) using recursive partitioning analysis. Historically the incidence of TEE in GBM patients is approximately 30%. As this study suggests dalteparin reduces the incidence of TEE, and does not have significant overlapping toxicities with most other drugs; its testing in a combined modality approach with other medications may be warranted in future trials.

Critically ill cancer patients are not consistently hypercoagulable after craniotomy

INTRODUCTION

Recent reports using thrombelastography have suggested that neurosurgical patients develop a hypercoagulable state in the postoperative period. Since venous thromboembolism is a potentially life threatening complication in these patients, we studied a similar population in our institution.

METHODS

We conducted a prospective pilot study to evaluate postoperative coagulation changes in critically ill cancer patients after craniotomy. Data collected included demographics, diagnoses, severity of illness, all hematological information (coagulation tests included conventional and TEG), therapies, and complications. Analysis included descriptive statistics, and multivariate regression analysis.

RESULTS

Eleven patients were included in the study. Mean age was 52 +/- 17 years, BMI 28 +/- 6.5, APACHE II and SOFA scores were 11.18 +/- 5.0 and 3.82 +/- 1.6 respectively. The Coagulation Index (CI), which is derived from the measured values of R, K, MA, and alpha angle was 1.22 +/- 3.5, R 4.2 +/- 1.6, K 2.0 +/- 2.1, MA 60.78 +/- 5.97, and alpha angle 66.88 +/- 14.9; while the Thrombodynamic Potential Index (TPI), which is derived from the measured values of K and MA only was 32.48 +/- 21. The CI correlated significantly with R, K, alpha angle, MA, TMA, TPI, PMA, E, A30 and A60 but not with the PTT, INR, or SOFA and APACHE II scores. One patient was hypocoagulable by CI and TPI values; in contrast, nine patients were hypercoagulable by TPI but only one by CI. There were no cases of VTE.

CONCLUSIONS

Hypercoagulability as defined by the CI was not a common finding in this study. Although the TPI indicated hypercoagulability in a large number of patients, we do not believe it is a good tool to assess the patient's clotting status or predictor of thrombosis because in contrast to the CI, it does not take into account the enzymatic portions of the clotting cascade. A larger TEG study is warranted to determine the clinical significance of these changes in this and other populations.

Medical management of brain tumor patients

Brain tumors can present challenging medical problems. Seizures, peritumoral edema, venous thromboembolism, fatigue, and cognitive dysfunction can complicate the treatment of patients who have primary or metastatic brain tumors. Effective medical management results in decreased morbidity and mortality and improved quality of life for affected patients.

A meta-analysis and systematic review of the efficacy and safety of anticoagulants as cancer treatment: impact on survival and bleeding complications

BACKGROUND

Preclinical evidence suggests that anticoagulants, in particular the low-molecular-weight heparins (LMWH), exert an antitumor effect, whereas clinical trials have reported conflicting results. The authors conducted a comprehensive, systematic review and meta-analysis of the evidence from randomized controlled trials (RCTs), to evaluate the impact of anticoagulants on survival and safety in cancer patients without venous thromboembolism.

METHODS

A comprehensive systematic literature review of RCTs was performed without language restrictions through May 2006 with subsequent updates to the end of 2006, including an exhaustive search of electronic databases, major conference proceedings, article references, and content experts. Two reviewers extracted data independently. Primary study outcomes were 1-year overall mortality and all bleeding complications. Major and fatal bleeding complications were secondary outcomes.

RESULTS

Across all 11 studies that were identified, anticoagulation significantly decreased 1-year overall mortality with a relative risk (RR) of 0.905 (95% confidence interval [95% CI], 0.847-0.967; P = .003). The RR for mortality was 0.877 (95% CI, 0.789-0.975; P = .015) for LMWH, compared with an RR of 0.942 (95% CI, 0.854-1.040; P = .239) for warfarin, resulting in an absolute risk difference (ARD) of 8% for LMWH and an ARD of 3% for warfarin. Improved survival with anticoagulation may be dependent on tumor type. Major bleeding episodes occurred less frequently in patients who received LMWH (ARD, 1%) compared with patients who received warfarin (ARD, 11.5%; P < .0001). Overall, fatal bleeding occurred rarely (ARD, 0.32%; P = .542).

CONCLUSIONS

Anticoagulants, particularly LMWH, significantly improved overall survival in cancer patients without venous thrombosis while increasing the risk for bleeding complications. However, given the limitations of available data, the use of anticoagulants as antineoplastic therapy cannot be recommended until additional RCTs confirm these results.

Epidemiology of venous thromboembolism in 9489 patients with malignant glioma

OBJECT

The authors sought to define the incidence of symptomatic venous thromboembolism (VTE) in patients harboring malignant gliomas.

METHODS

The authors conducted a retrospective analysis of data obtained in all cases of malignant glioma diagnosed in California during a 6-year period; the occurrence of a VTE was identified using linked hospital discharge data. The Cox proportional hazard model was used to analyze the association of specific risk factors with the development of a VTE or death within 2 years of the cancer diagnosis. Among 9489 cases, the 2-year cumulative incidence of VTE was 7.5% (715 cases), with a rate of 16.1 events per 100 person-years during the first 6 months. Three hundred ninety-one (55%) of these 715 cases were diagnosed within 61 days of major neurosurgery. Risk factors for VTE included older age (hazard ratio [HR] 2.6, confidence interval [CI] 2.0-3.4 for age range 65-74 years compared with < or = 45 years), glioblastoma multiforme histology (HR 1.7, CI 1.4-2.1), three or more chronic comorbidities (HR 3.5, CI 2.8-4.3 [compared with no comorbidity]), and neurosurgery within 61 days (HR 1.7, CI 1.3-2.3). Patients in whom a VTE was present were at higher risk of dying within 2 years (HR 1.3, CI 1.2-1.4). In a nested case-control analysis of all VTE cases, there was no association between insertion of a vena cava filter and the risk of a recurrent VTE.

CONCLUSIONS

In patients harboring a glioma there was a very high incidence of symptomatic VTEs, particularly within 2 months of neurosurgery. The development of a VTE was associated with a 30% increase in the risk of death within 2 years. Further studies are needed to determine if risk stratification and the use of medical prophylaxis after neurosurgery improves outcomes.

Massive blood transfusion in choroid plexus tumor surgery: 10-years' experience

STUDY OBJECTIVE

To describe our 10 years of experience with childhood choroid plexus tumors (CPTs).

DESIGN

Retrospective chart analysis.

SETTING

Operating room and pediatric intensive care unit (PICU) of a university hospital.

PATIENTS

18 infants and children undergoing CPT surgery from 1995 to 2004, 11 of whom were younger than 12 months.

MEASUREMENTS

Perioperative hematologic and coagulation data were measured as well as estimated red cell volume variations (as a reliable index of blood loss) in the perioperative period, together with coagulation parameters.

RESULTS

Greater blood loss was recorded in the infant group vs older children (percentage of estimated red cell volume loss, 1.31 +/- 1.79% vs 0.20 +/- 0.17% [P < 0.01] and 1.50 +/- 1.86% vs 0.29 +/- 0.21% [P < 0.01] on PICU admission and after 72 hours, respectively). Platelet count decrease was similarly noted (51.60 +/- 28.06 vs 27.57 +/- 11.98, P < 0.05, as percentage of preoperative count). Patients operated on in the neonatal period showed the highest blood loss and related coagulation impairment.

CONCLUSION

Younger CPT surgery patients present an increased risk versus their older counterparts of massive bleeding resulting in hemodynamic instability and coagulative impairment.

Supportive Care of Brain Tumor Patients

The supportive care of patients who have brain tumors consists mainly of the treatment of brain edema, seizures, venous thromboembolism, and cognitive dysfunction. Each of these complications may occur in patients who have primary or metastatic brain tumors. The development of any of these complications significantly increases the morbidity and mortality associated with brain tumors. Effective treatment is usually possible, however, and can result in an improved quality of life for these patients.

Phase 2 trial of radiation plus high-dose tamoxifen for glioblastoma multiforme: RTOG protocol BR-0021

Preclinical studies support the concept that inhibition of protein kinase C (PKC) by tamoxifen (TAM) should provide both antineoplastic effects and radiosensitization. High-dose TAM (80 mg/m2 p.o. daily in divided doses) was given with and after conventional radiotherapy (XRT) to inhibit PKC-mediated signaling, which is known to be enhanced in glioblastoma (GBM). Seventy-seven patients were accrued between December 2000 and December 2001; two were ineligible and not included in the efficacy results. Pretreatment characteristics of the patients included the following: 52% were less than 60 years of age, 39% had a Zubrod score of 0, 70% had minor or no neurological symptoms, and 65% were Radiation Therapy Oncology Group-recursive partition analysis (RPA) class III and IV. Eighty-six percent of patients achieved acceptable dosing of TAM. Notable toxicity included late radiation grade 3 in two patients and thromboembolic events in 16 patients (two grade 2, 10 grade 3, three grade 4, and one grade 5), for an incidence of 20.8% (which is lower than expected, based on the literature for deep vein thrombophlebitis in GBM patients not receiving TAM). Median survival time (MST) was 9.7 months as compared (by three different statistical methodologies) to the historical GBM control database of 1457 RPA class III, IV, and V drug/XRT-treated patients. After controlling for RPA class IV, the MST was 11.3 months, which compares to the historical RPA control of 11.3 months (P = 0.37). The results obtained do not exhibit a substantial advance over those of previous studies with various XRT/drug doublets, including BCNU. However, as TAM does not have significant overlapping toxicities with most other drugs, its testing in a combined modality approach with other medications may be justified in future clinical trials. Historically, the incidence of thromboembolic events in GBM patients is approximately 30%. The lower-than-expected incidence seen here has also been observed in other high-dose TAM GBM studies. We speculate that TAM inhibited the PKC-mediated phosphorylation of coagulation factors.

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.

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.

Hemostatic changes in pediatric neurosurgical patients as evaluated by thrombelastograph

Thromboembolic events are a known complication in neurosurgical patients. There is evidence to suggest that a hypercoagulable state may develop perioperatively. Thrombelastograph (TEG) coagulation analysis is a reliable method of evaluating hypercoagulability. We evaluated coagulation by using TEG data in pediatric neurosurgical patients undergoing craniotomy to determine whether a hypercoagulable state develops intraoperatively or postoperatively. Thirty children undergoing craniotomy for removal of a tumor or seizure focus were studied. Blood was analyzed with TEG) data by using native and celite techniques, at three time points for each patient: preoperatively after induction of anesthesia; intraoperatively during closure of the dura; and on the first postoperative day. Compared with preoperative indices, closing and postoperative celite TEG values were indicative of hypercoagulability with shortened coagulation time values (P < 0.001), prolonged alpha angle divergence values (P < 0.001), and above-normal TEG coagulation indices (P < or = 0.002). Reaction time values were shortened, and maximal amplitude of clot strength values were prolonged but did not reach statistical significance. Hypercoagulation develops early after resection of brain tissue in pediatric neurosurgical patients as assessed by using TEG data. Further studies are needed to determine the clinical significance of this hypercoagulable state.

IMPLICATIONS

Hypercoagulability in postoperative neurosurgical patients has been demonstrated in the adult population, but few studies have dealt with the pediatric population. We found that children undergoing craniotomy for focal resection, lobectomy, and hemispherectomy are hypercoagulable as detected by thrombelastograph coagulation analysis. Further studies are needed to determine whether this is clinically significant.

Factor XIII deficiency and postoperative hemorrhage after neurosurgical procedures

BACKGROUND

Factor XIII is of physiological importance for hemostasis, especially in patients undergoing surgery. It catalyzes the enzymatic cross-linking of fibrin monomers into stable polymers and protects polymers from plasmatic and nonspecific degradation. Postoperative hemorrhage in patients with congenital and acquired Factor XIII deficiencies has been described in various surgical fields. However, there are no data about the incidence and clinical relevance of decreased Factor XIII after neurosurgical procedures. The objective of our study was to investigate the association between Factor XIII deficiency and postoperative hemorrhage after intracranial surgery.

METHODS

A total of 1264 patients who underwent intracranial operations were reviewed retrospectively. Standard coagulation parameters were monitored during the perioperative course in all patients. Factor XIII testing was performed postoperatively in 34 patients in whom coagulopathies were suspected despite normal platelets, fibrinogen, prothrombin, and partial thromboplastin time. Data were analyzed to evaluate the association of Factor XIII deficiency and major postoperative hemorrhage.

RESULTS

In this series of 1264 patients, a total of 20 patients (1. 6%) suffered from a major postoperative hemorrhage. Of the 34 patients with suspected coagulopathies and postoperative Factor XIII testing, 11 had a major postoperative hemorrhage. Normal levels of Factor XIII, defined as more than 60%, were found in 26 of the 34 patients. Factor XIII deficiency, defined as less than 60%, was found in eight patients. All patients with Factor XIII deficiency (n = 8) had a major postoperative hemorrhage. Of the remaining 26 patients with normal Factor XIII levels only three had a postoperative hemorrhage (p < 0.00001, Fisher's exact test).

CONCLUSIONS

Decreased Factor XIII activity may be associated with an increased risk of postoperative hemorrhage after intracranial surgery.

Acquired APC resistance in neurosurgical patients may not be a risk factor for postoperative deep vein thrombosis

Acquired resistance to activated protein C has been reported during oral contraception and pregnancy. Its thrombogenic potential was studied in 41 neurosurgical patients who were enrolled in the placebo group of a thromboprophylaxis trial. Normalized activated protein C sensitivity ratio (nAPC-SR), clotting activity of factors V and VIII, and levels of protein C antigen were measured prior to and at days 3 and 7 after surgery. Bilateral venography was done in all patients at days 8-10 to demonstrate deep vein thrombosis. A lowered nAPC-SR was found in 76% (baseline), 80% (day 3), and 88% (day 7) of patients. It was inversely related to factor VIII clotting activity (p = .0003) and protein C antigen, (p = .02). Deep vein thrombosis was demonstrated in 30% of patients with a normal nAPC-SR and in 23% of patients with a lowered nAPC-SR. Pulmonary embolism was not observed. Multivariate analysis did not identify a lowered nAPC-SR as a thrombotic risk factor, in contrast with gender (women, p = .02) and Quetelet index (> or = 25 kg/m2, p = .006). Our data provide no evidence that acquired activated protein C resistance, frequently found in neurosurgical patients, contributes to their high risk of postoperative deep vein thrombosis.

Enoxaparin increases the incidence of postoperative intracranial hemorrhage when initiated preoperatively for deep venous thrombosis prophylaxis in patients with brain tumors

OBJECTIVE

Prophylactic therapies have demonstrated efficacy in reducing the incidence of deep venous thrombosis (DVT) in neurosurgical patients. Retrospective analysis of patients undergoing neurosurgical procedures at the University of Michigan demonstrated a high incidence (14%) of postoperative DVT among patients with intracranial neoplasms treated with sequential compression device (SCD) prophylaxis alone. Therefore, we investigated the efficacy and safety of the low-molecular weight heparin enoxaparin in preventing DVT in patients with brain tumors. The goal of the study was to compare SCD, enoxaparin, and combined SCD/enoxaparin prophylaxis among patients requiring surgery for treatment of intracranial neoplasms.

METHODS

Eligible patients were randomized to SCD, enoxaparin, or combined therapy. Treatment was initiated before the induction of anesthesia and was continued throughout the hospital stay. Patients were screened for DVT, using duplex imaging, on four occasions in the first 1 month after surgery. The incidences of DVT and serious adverse events were compared between groups using analysis of variance and the Dunnet two-sided t test.

RESULTS

Sixty-eight patients completed the study. Postoperative DVT occurred in 3 of 22 (13.6%) SCD-treated patients, 1 of 23 (4.3%) enoxaparin-treated patients, and 4 of 23 (17.4%) SCD/enoxaparin-treated patients. Differences were not statistically significant. Postoperative intracranial hemorrhage did not occur in patients in the SCD-treated group, whereas 5 of 46 patients receiving low-molecular weight heparin suffered clinically significant intracranial hemorrhage. The study was terminated because of the increased incidence of adverse events in the enoxaparin-treated groups.

CONCLUSION

Enoxaparin therapy initiated at the time of anesthesia induction increases postoperative intracranial hemorrhage.

Selected complications in neuro-oncology patients

OBJECTIVES

To identify the causes of and discuss nursing management of those complications that are unique to the brain tumor patient population.

DATA SOURCES

Published articles and books related to neurological and nonneurological complications in the neuro-oncology patient.

CONCLUSIONS

Seizures, cerebral edema, thromboembolism, and endocrine dysfunction are several complications experienced by the neuro-oncology patient. These complications can be caused by the tumor or treatment of this disease.

IMPLICATIONS FOR NURSING PRACTICE

Care of the neuro-oncology patient is complex. Knowledge of the potential complications that patients may experience and how to manage these problems serves to enhance their quality of life.

Hemostasis activation in patients undergoing brain tumor surgery

Patients undergoing brain tumor surgery are at high risk for the occurrence of a thromboembolic event. To identify a laboratory marker suitable for risk estimation the authors studied the perioperative time pattern of routine coagulation parameters and the specific hemostasis activation marker D-dimer in 28 consecutive patients at high risk (11 patients with glioma and eight patients with meningioma) and low risk (nine patients with metastases) for thromboembolism, as previously reported. As is typical during major surgery, most of the routine parameters declined, probably because of hemodilution, and recovered postoperatively to values higher than baseline, probably because of an acute-phase reaction. On Days 2 and 7 after surgery no difference in the routine parameters was recorded between patients at high (meningioma and glioma) and low risk (metastasis). The level of D-dimer was elevated at baseline in patients with metastasis, indicating a hemostatic hyperactivity that is usual in cancer patients. During surgery a marked increase in D-dimer levels occurred in patients with meningioma and glioma (pre- and postoperative median 90/2000 and 100/1020 ng/ml, respectively), but the increase was less pronounced in patients with metastasis (320/660 ng/ml). Postoperatively, D-dimer declined in patients with metastases to lower than preoperative levels (Day 7, 270 ng/ml); in patients with meningioma or glioma, however, D-dimer levels remained elevated until Day 7 (450 and 200 ng/ml, respectively). These results indicate that levels of D-dimer correlate with the reported high risk for thromboembolism in patients with meningioma and glioma, and D-dimer should be evaluated for its use in estimating individual risk and the efficiency of its use in the control of prophylactic treatment.

Haemostatic changes during surgery for primary brain tumours

OBJECTIVE

Primary brain tumours may be associated with coagulation disorders which can pose intraoperative and postoperative management difficulties. The aim was to evaluate the coagulation profile of patients with brain tumours undergoing surgery using thromboelastography (TEG) in combination with simple laboratory tests.

METHODS

Fifty adult patients with primary brain tumours larger than 4 cm in maximum diameter and no history of coagulation disorders were studied in a prospective, observational manner over a one year period. Preoperative, intraoperative, and postoperative measurements included haemoglobin concentration, platelet count, prothrombin and partial thromboplastin times, fibrin(ogen) degradation product concentration, D-dimer concentration, and TEG.

RESULTS

Eleven patients (22%) had abnormal intraoperative TEGs, of whom six (12%) subsequently developed haematomas requiring surgical evacuation. The coagulopathy seemed to be hyperfibrinolysis in two cases (4%) and disseminated intravascular coagulation in four (8%). There was no preoperative difference in reaction time (R time) for clot formation between the non-haematoma and haematoma groups(mean 11.44 (SD 3.42) v 12.33 (2.50) min, P=0.46). However, when other preoperative indices were compared, in the non-haematoma group, K time (time to reach a clot amplitude of 20 mm) was shorter (6.72 (2.15) v 10.56 (3.50) min, P=0.001), rate of clot growth (å) was faster (43.67 degrees (7.53) v 27.11 degrees (5.42), P<0.0001) and maximum amplitude of clot strength (MA) was greater (52.64 (7.85) v 40.33 (6.59) mm, P<0.001). Intraoperatively, R time was significantly shortened in the non-haematoma group, (7.67 (1.78) min, P<0.0001) unlike the haematoma group (10.67 (1.58) minutes, P=0.11).

CONCLUSIONS

Although these results indicate a general hypercoagulability during brain tumour surgery, in certain cases, a predisposition towards hypocoagulability may exist even before surgery, detectable only when the physical characteristics of clot formation are studied by TEG. Judicious replacement of clotting factors, platelets, and antifibrinolytic agents should be considered intraoperatively if the TEG is abnormal, without waiting for laboratory test results.

Incidence of risk of thromboembolism during treatment high-grade gliomas: a prospective study

A prospective study of a series of 77 patients on adjuvant radiochemotherapy following surgery for high-grade gliomas was conducted to evaluate the risk of deep vein thrombosis and identify risk factors. We found a 20.8% risk of deep vein thrombosis at 12 months (standard error = 4.8%) and a 31.7% risk (standard error = 7.4%) at 24 months (Kaplan-Meier method). Twenty patients (26%) developed deep vein thrombosis with a maximum incidence within the first 7 months after surgery when chemotherapy was still being administered, often with corticosteroids. The risk factors identified were histology (glioblastoma versus anaplastic astrocytoma, P = 0.032, log rank test; 0.0485 L-ratio) and the presence of paresis (P = 0.010, log rank test; 0.0161 L-ratio). A borderline tendency was found for an association between the deep vein thrombosis site and the side of paresis (P = 0.103, Fisher's exact test). Four patients (5%) had massive pulmonary embolism, which was fatal in 3 (4%).

Coagulation alterations in patients undergoing elective craniotomy

BACKGROUND

Thromboembolism remains a major problem in patients scheduled for craniotomy. The present study examined parameters of coagulation and fibrinolysis in 15 patients undergoing elective craniotomy in the perioperative period.

METHODS

Plasma concentrations of thrombin antithrombin III complex (TAT), prothrombin fragment 1 + 2 (F1 + 2), and d-dimer were measured before and after induction of anesthesia, 60 minutes and 180 minutes after the beginning of surgery, and on the first postoperative morning.

RESULTS

TAT, a marker of activation of coagulation, increased significantly (p < 0.05) from the preoperative measurements to the data obtained 60 minutes after beginning the surgery, reaching a maximum of 180 minutes after the start of surgery. F1 + 2, also indicating activation, showed a similar concentration time course with an intraoperative maximum. D-dimer, a marker of fibrinolysis, tended to increase slightly beginning 180 minutes after surgery with a maximum on the morning after surgery. Statistical significance for F1 + 2 and d-dimer was not found.

CONCLUSIONS

This study showed a transient activation of coagulation with an intraoperative maximum in patients undergoing craniotomy. This result could be due to a liberation of thromboplastin from brain tissue.