Coagulation alterations in patients undergoing elective craniotomy

Intermittend pneumatic venous thrombembolism (VTE) prophylaxis during neurosurgical procedures

BACKGROUND

The management of perioperative venous thrombembolism (VTE) prophylaxis is highly variable between neurosurgical departments and general guidelines are missing. The main issue in debate are the dose and initiation time of pharmacologic VTE prevention to balance the risk of VTE-based morbidity and potentially life-threatening bleeding. Mechanical VTE prophylaxis with intermittend pneumatic compression (IPC), however, is established in only a few neurosurgical hospitals, and its efficacy has not yet been demonstrated. The objective of the present study was to analyze the risk of VTE before and after the implementation of IPC devices during elective neurosurgical procedures.

METHODS

All elective surgeries performed at our neurosurgical department between 01/2018-08/2022 were investigated regarding the occurrence of VTE. The VTE risk and associated mortality were compared between groups: (1) only chemoprophylaxis (CHEMO; surgeries 01/2018-04/2020) and (2) IPC and chemoprophylaxis (IPC; surgeries 04/2020-08/2022). Furthermore, general patient and disease characteristics as well as duration of hospitalization were evaluated and compared to the VTE risk.

RESULTS

VTE occurred after 38 elective procedures among > 12.000 surgeries. The number of VTEs significantly differed between groups with an incidence of 31/6663 (0.47%) in the CHEMO group and 7/6688 (0.1%) events in the IPC group. In both groups, patients with malignant brain tumors represented the largest proportion of patients, while VTEs in benign tumors occurred only in the CHEMO group.

CONCLUSION

The use of combined mechanical and pharmacologic VTE prophylaxis can significantly reduce the risk of postoperative thromboembolism after neurosurgical procedures and, therefore, reduce mortality and morbidity.

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.

Reduced risk of venous thromboembolism with the use of intermittent pneumatic compression after craniotomy: a randomized controlled prospective study

OBJECTIVE

The term "venous thromboembolism" (VTE) subsumes deep venous thrombosis (DVT) and pulmonary embolism. The incidence of DVT after craniotomy was reported to be as high as 50%. Even clinically silent DVT may lead to potentially fatal pulmonary embolism. The risk of VTE is correlated with duration of surgery, and it appears likely that it develops during surgery. The present study aimed to evaluate intraoperative use of intermittent pneumatic compression (IPC) of the lower extremity for prevention of VTE in patients undergoing craniotomy.

METHODS

A total of 108 patients undergoing elective craniotomy for intracranial pathology were included in a single-center controlled randomized prospective study. In the control group, conventional compression stockings were worn during surgery. In the treatment group, IPC of the calves was used in addition. The presence of DVT was evaluated by Doppler sonography pre- and postoperatively.

RESULTS

Intraoperative use of IPC led to a significant reduction of VTE (p = 0.029). In logistic regression analysis, the risk of VTE was approximately quartered by the use of IPC. Duration of surgery was confirmed to be correlated with VTE incidence (p < 0.01); every hour of surgery increased the risk by a factor of 1.56.

CONCLUSIONS

Intraoperative use of IPC significantly lowers the incidence of potentially fatal VTE in patients undergoing craniotomy. The method is easy to use and carries no additional risks.■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class I.Clinical trial registration no.: DRKS00011783 (https://www.drks.de).

[Some features controlling the blood D-dimer level after resection of malignant brain glioma]

A high blood D-dimer level is often diagnosed in patients with malignant brain glioma (MBG), with 24% of these patients being detected with deep vein thrombosis of the leg and/or pulmonary embolism (PE). The cause of an elevated blood D-dimer level in most other cases remains unclear. The purpose of this study is to identify the features associated with an increased blood D-dimer level in patients after MBG resection, which may be used to improve the efficacy of adjuvant radiation therapy (ART).

RESULTS

The study included 50 patients. Three to four weeks after resection of malignant brain glioma (MBG), the blood D-dimer level was determined in patients immediately before the onset of ART. An increase in the blood D-dimer level more than by 0.25 μg/mL was detected in 78% of patients. More often, a high D-dimer level was detected in patients aged 60 years or more. In the same age group, an increase in the D-dimer level was significantly larger (p<0.05) than in younger patients (1.2 and 0.6 μg/mL, respectively). The degree of brain tumor malignancy did not affect the rate and value of an increase in the blood D-dimer level.

CONCLUSION

Our findings indicate that an increased blood D-dimer level in patients without symptoms of venous thrombosis after craniotomy for MBG is more pronounced in patients aged 60 years and over. The degree of glioma malignancy has no significant effect on this indicator.

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.

D-dimer plasma level: a reliable marker for venous thromboembolism after elective craniotomy

OBJECT

The incidence of deep venous thrombosis (DVT) after craniotomy is reported to be as high as 50%. In outpatients, D-dimer levels of more than 0.5 mg/L indicate venous thromboembolism (VTE, which subsumes DVT and pulmonary embolism [PE]) with a sensitivity of 99.4% and a specificity of 38.2%. However, D-dimer levels are believed to be unreliable in postoperative patients. The authors undertook the present study to test the hypothesis that D-dimer levels would be systematically raised in a postoperative population and to define a feasible threshold for identification of VTE.

METHODS

Doppler ultrasonography of the lower extremity was performed pre- and postoperatively to evaluate for DVT in 101 patients who underwent elective craniotomy. D-dimer levels were assessed preoperatively and on the 3rd, 7th, and 10th days after surgery. Statistical analysis was carried out to define a feasible threshold for D-dimer levels.

RESULTS

D-dimer plasma levels were found to be systematically raised postoperatively, and they differed between patients with and without VTE in a highly significant way. On the 3rd day after surgery, D-dimer levels of more than 2 mg/L indicated VTE with a sensitivity of 95.3% and a specificity of 74.1%, allowing for the definition of a feasible threshold. D-dimer levels of more than 4 mg/L were observed in all patients who had PE during the postoperative period (n = 9). Ventilation time and duration of surgery were identified as highly significant risk factors for the development of VTE.

CONCLUSIONS

Using a threshold of 2 mg/L, D-dimer levels will indicate VTE with a high degree of sensitivity and specificity in patients who have undergone craniotomy. Pulmonary embolism seems to be indicated by even higher D-dimer levels. Given that the development of D-dimer plasma levels in the postoperative period follows a principle that can be predicted and that deviations from it indicate VTE, this principle might be applicable to other types of surgery.

Acute Brain Infarcts After Spontaneous Intracerebral Hemorrhage

Background and Purpose— We aimed to determine the prevalence of acute brain infarcts using diffusion-weighted imaging (DWI) in patients with spontaneous intracerebral hemorrhage (ICH).

Methods— We collected data on consecutive patients with spontaneous ICH admitted to our institution between August 1, 2006 and December 31, 2008 and in whom DWI was performed within 28 days of admission. Patients with hemorrhage attributable to trauma, tumor, aneurysm, vascular malformation, and hemorrhagic conversion of arterial or venous infarction were excluded. Restricted diffusion within, contiguous with, or immediately neighboring the hematoma or chronic infarcts was not considered abnormal. Using multivariable logistic regression, we evaluated potential predictors of DWI abnormality including clinical and radiographic characteristics and treatments. A probability value <0.05 was considered significant in the final model.

Results— Among 118 spontaneous ICH patients (mean 59.6 years, 47.5% male, and 31.4% white) who also underwent MRI, DWI abnormality was observed in 22.9%. The majority of infarcts were small (median volume 0.25 mL), subcortical (70.4%), and subclinical (88.9%). Factors independently associated with DWI abnormality were prior ischemic stroke ( P =0.002), MAP lowering by ≥40% ( P =0.004), and craniotomy for ICH evacuation ( P =0.001).

Conclusion— We found that acute brain infarction is relatively common after acute spontaneous ICH. Several factors, including aggressive blood pressure lowering, may be associated with acute ischemic infarcts after ICH. These preliminary findings require further prospective study.

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.

Massive congenital intracranial teratoma: perioperative coagulation impairment

Massive congenital intracranial teratoma is a rare neoplasm with a poor prognosis. Surgery may be curative only if complete resection can ben obtained. Several single case reports have been published in the pediatric literature, mostly focusing on prenatal diagnosis. The authors describe six patients with congenital intracranial teratoma treated at their institution in the past decade. Perioperatively, a marked hemostatic derangement was observed in three of them undergoing surgery: the pathophysiology of this complication is discussed. The surgical indication itself represents an ethical dilemma when treating a large intracranial tumor with partial destruction and replacement of brain structures.

Changes in Blood Coagulation Markers Associated with Uterine Artery Embolization for Leiomyomata

PURPOSE

To determine whether a transient hypercoagulable state is induced by the uterine artery embolization (UAE) procedure.

MATERIALS AND METHODS

Serial periprocedure blood samples were obtained from 27 patients undergoing the UAE procedure. Five blood samples were obtained from each patient at set time intervals: before the procedure (for baseline determination), immediately before and after embolization of the uterine arteries, 90 minutes after conclusion of the procedure, and between 18 and 24 hours later. Each blood sample was analyzed for the peripheral levels of the following parameters: thrombin-antithrombin complex (TAT), prothrombin fragment 1.2 (F1.2), platelet factor 4 (PF4), D-dimer, and plasmin-alpha(2)-antiplasmin complex (PAP). For each parameter, the baseline values were statistically compared with the pre- and postembolization values for each individual to detect change over time. Overall and global occasion effects for continuous variables were assessed with the Friedman statistic and individual comparisons between occasions with the Wilcoxon signed-rank test.

RESULTS

No evidence was found for a difference in coagulability among the five occasions for D-dimer (P =.7645) or PF4 (P =.09). All three of the remaining measures were found to have statistically significant differences (P <.0001 for F1.2, P =.0026 for PAP, and P =.0006 for TAT). No evidence was found for a difference between preprocedure and preembolization levels for these three latter parameters (P =.595 for F1.2, P =.128 for PAP, P =.9705 for TAT). Hypercoagulability potential as measured by prothrombinase and F1.2 generation increased between preembolization samples and each of the successive postprocedure samples (P <.0001, P <.0001, P =.0082), whereas PAP increased at 90 minutes (P =.0023) and TAT increased immediately after embolization (P <.0001). No clinically apparent thrombotic complications occurred among any of the patients studied.

CONCLUSIONS

Surrogate markers of hypercoagulability increase as a result of UAE, suggesting that a prothrombotic state may result after the procedure.

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.

Coagulofibrinolytic changes after isolated head injury are not different from those in trauma patients without head injury

BACKGROUND

To test the hypothesis that tissue factor release, thrombin activation, fibrin formation, and fibrinolysis after an isolated head injury are equal to those in patients without head injury, as well as to investigate the precise time course of the coagulation and fibrinolytic abnormalities after head injury, we performed prospective and retrospective studies.

METHODS AND RESULTS

In the prospective study, 5 patients with isolated head injury and 11 trauma patients without head injury took part in this study. Tissue factor antigen concentration, prothrombin fragment F1+2, thrombin antithrombin complex, fibrinopeptide A, and fibrin degradation products (D-dimer) were measured on the day of admission, and days 1, 2, 3, and 4 after admission. The levels of all five hemostatic molecular markers were markedly elevated on the day of admission, and then gradually decreased to day 4. The levels and the time course of these hemostatic markers in patients with isolated head injury were not different from those in the control patients. The same incidence of disseminated intravascular coagulation between the two groups was also observed. In the retrospective study, the records of fibrinopeptide Bbeta15-42, plasmin antiplasmin complex, plasminogen activator inhibitor-1 antigen concentration (PAI-1 antigen), and PAI-1 activity in 76 trauma patients were reviewed. On the basis of the exclusion criteria, 9 patients with isolated head injury and 30 control patients were selected for the study group. Fibrinopeptide Bbeta15-42 and plasmin antiplasmin complex markedly elevated on the day of admission, then decreased on day 1, and tended to increase to day 5. Markedly elevated PAI-1 antigen and PAI-1 activity on the day of admission significantly decreased on day 1 and recovered to the normal values on day 5. The changes of these molecular markers in patients with isolated head injury were equal to those in the control patients.

CONCLUSION

We systematically elucidated the time course of coagulation and fibrinolysis after isolated head injury. We further demonstrated that changes in coagulofibrinolytic and antifibrinolytic systems in patients with isolated head injury are not different from those in patients without head injury.