Stenting for acute cerebral venous sinus thrombosis in the superior sagittal sinus

Abstract

Endovascular treatment for superior sagittal sinus (SSS) thrombosis is not always successful because of difficult access and long thrombus lesions. We report the first two cases of patients with acute cerebral venous sinus thrombosis at the SSS that was not recanalized by anticoagulation, mechanical thrombectomy, or thrombolysis, but was successfully treated by stent placement. Case 1 was a 37-year-old woman with bilateral subdural hematomas. Digital subtraction angiography showed obstruction of the sinus from the SSS to the right transverse sinus. Recanalization was achieved by selective thrombolysis using urokinase followed by balloon angioplasty, but re-occlusion occurred on the next day of treatment. Repeated endovascular treatment including balloon angioplasty, thrombus aspiration and thrombolysis using recombinant tissue plasminogen activator failed to achieve recanalization. We thus placed intracranial stents in the SSS, which did achieve recanalization. Case 2 was a 69-year-old woman with a small infarction in the left parietal lobe. Digital subtraction angiography showed sinus obliteration from the SSS to the bilateral transverse sinuses. Recanalization was not achieved by balloon angioplasty, thrombus aspiration and selective thrombolysis. We thus placed intracranial stents in the SSS, which did achieve recanalization. Postoperative course was uneventful in both cases and venous sinus patency was confirmed by venography >1.5 years after treatment. When conventional endovascular strategies have been unsuccessful, placement of intracranial stents, which can easily gain access to the distal part of the SSS as compared with carotid stents, may be a useful treatment option for the acute sinus thrombosis in this region.

Introduction

Cerebral venous sinus thrombosis (CVST) is associated with various clinical symptoms, and late diagnosis can result in poor outcome. Although anticoagulation is the only reported treatment with high-level evidence of its efficacy from randomized controlled trials (RCTs),^1–3 many reports suggest the usefulness of endovascular treatment, such as mechanical thrombectomy,⁴ aspiration thrombectomy⁵ and selective thrombolysis.⁶ We report two patients with acute CVST involving the superior sagittal sinus (SSS) who were successfully treated with stent placement. In both cases, previously reported endovascular treatments (selective thrombolysis using urokinase or recombinant tissue plasminogen activator (rt-PA), balloon angioplasty or thrombus aspiration with a thrombus aspiration catheter)⁷ were unsuccessful, but stent placement achieved recanalization of the obstructed sinuses and provided good clinical outcomes.

Case reports

Case 1

A 37-year-old woman had complained of severe headache for two days. She had a sudden disturbance of consciousness and exhibited abnormal behavior, and consequently was transferred to our hospital. On admission, her Glasgow Coma Scale (GCS) score was 13 (E3V4M6). She did not have either anticoagulation use or traumatic episodes. Fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) images showed thin bilateral subdural hematomas and thrombosis at the superior sagittal sinus (SSS) (Figure 1(a)). MR venogram (MRV) shows sinus occlusion from the SSS to the right transverse sinus (Figure 1(b)). We decided to confirm the diagnosis by digital subtraction angiography (DSA) because of the estimated extent of thrombosis and degree of cortical reflux. DSA was then performed, and sinus thrombosis from the SSS to the right transverse sinus with cortical venous reflux was confirmed (Figure 1(c)). The patient’s oral contraceptive was discontinued, and anticoagulation therapy was initiated.

Figure 1.

(a) Fluid-attenuated inversion recovery magnetic resonance (MR) image showing bilateral subdural hematomas (arrows) and thrombosis at superior sagittal sinus (SSS) (arrowhead). (b) MR venogram shows sinus occlusion from the SSS (arrow) to the right transverse sinus (arrowheads). (c) Right internal carotid artery angiogram (ICAG) showing sinus occlusion from the SSS to the right transverse sinus (arrowheads) and venous congestion before endovascular therapy (arrow). (d) Right ICAG after the first endovascular therapy showing re-occlusion from the SSS to the right transverse sinus (arrowheads). (e) Right ICAG after the second endovascular therapy showing recanalization from the SSS without the distal part to the right transverse sinus (arrowheads) and improved venous perfusion. (f) Computed tomographic venograms two years after endovascular therapy showing recanalization of the occluded SSS without the distal part. (g) Maximum-intensity projection view showing patency of the SSS. Stent markers are indicated by arrowheads.

Because there was no apparent risk factor for subdural hematoma, CVST might have been an underlying cause of the hematoma. Combination of the bilateral subdural hematomas and extensive obstruction of the venous sinus with cortical reflex suggest that the patient had intracranial hypertension. We therefore considered the patient suitable for early revascularization therapy. Systemic heparinization was performed, and a guiding catheter was inserted into the left internal jugular vein under local anesthesia. Balloon angioplasty was performed using a 3.5 mm × 15 mm Gateway™ Over-The-Wire PTA Dilatation Catheter (Stryker, Kalamazoo, MI, USA) from the SSS to the right transverse sinus. Selective thrombolysis with 120,000 U of urokinase followed by balloon angioplasty led to recanalization, and venous congestion was improved. However, the patient’s symptoms did not improve by the next day, and re-obstruction was confirmed on DSA (Figure 1(d)). We therefore decided to repeat the endovascular treatment. Angioplasty, selective thrombolysis with 240,000 U of urokinase and 4.8 ×10⁶ U of rt-PA, and thrombus aspiration using an Eliminate™ Aspiration Catheter (Terumo, Tokyo, Japan) failed to achieve recanalization. Therefore, after administration of aspirin (200 mg) and clopidogrel (300 mg), we introduced a PROWLER® SELECT™ Plus (Codman & Shurtleff, Johnson & Johnson, Raynham, MA, USA) microcatheter distal to the occluded segment, and placed intracranial stents (ENTERPRISE™ Vascular Reconstruction Device; Codman & Shurtleff, Johnson & Johnson) dorsally in tandem in the SSS until the sinus could be visualized. Two stents were sufficient for successful recanalization of the thrombosed sinuses without the distal part of the SSS (Figure 1(e)).

Anticoagulation and antiplatelet therapies were continued. On post-procedure day 38, the patient was discharged without any neurological deficits with the modified Rankin Scale (mRS) of 0. Venous sinus patency was confirmed by DSA performed three weeks after treatment and computed tomographic venography performed two years after treatment (Figure 1(f) and (g)). She had no neurological deficit with the mRS of 0 at two years after treatment.

Case 2

A 69-year-old woman experienced motor weakness in the right extremities and immediate onset of status epilepticus, and was transferred to our hospital. On admission, her GCS score was 13 (E3V4M6) and her National Institutes of Health Stroke Scale score was 6. FLAIR MR images showed cerebral infarction in the left parietal lobe (Figure 2(a)). MRV showed sinus occlusion from the SSS to the bilateral transverse sinuses (Figure 2(b)). The patient underwent DSA, which confirmed sinus thrombosis extending from the SSS to the bilateral transverse sinuses (Figure 2(c)).

Figure 2.

(a) Fluid-attenuated inversion recovery magnetic resonance image showing a hyperintense area in the left parietal lobe. (b) MR venogram (MRV) shows sinus occlusion from the superior sagittal sinus (SSS) (arrow) to the bilateral transverse sinuses (arrowheads). (c) Right internal carotid artery angiogram (ICAG) showing sinus occlusion from the SSS to the bilateral transverse sinuses (arrowheads). (d) Right ICAG after endovascular therapy showing recanalization from the SSS to the bilateral transverse sinuses (arrowheads). (e) MRV two years after endovascular therapy showing patency of the SSS and the bilateral transverse sinuses (arrowheads) without a finding of cortical reflux.

Anticoagulation therapy was initiated. Although the occlusion of the venous sinus was extensive, the ischemic lesion was small. For this reason, and because of her severe clinical symptoms, the patient was considered suitable for early revascularization. Balloon angioplasty, selective thrombolysis (urokinase 240,000 U and rt-PA 2.4 × 10⁶ U) and thrombus aspiration were not effective. Therefore, intracranial stents (ENTERPRISE VRD) were placed in tandem from the distal part of the SSS thrombus, and recanalization was achieved without the distal part of the SSS (Figure 2(d)).

Anticoagulation and antiplatelet therapies were continued. On post-procedure day 28, the patient was discharged with slight disability in her right extremities with the mRS of 2. Venous sinus patency was confirmed by DSA performed two weeks after treatment and MR imaging 1.5 years after treatment (Figure 2(e)). MRV 1.5 years after endovascular therapy showing patency of the SSS and the bilateral transverse sinuses without a finding of cortical reflux. She was independent with the mRS of 1 at 1.5 years after treatment.

Discussion

American Heart Association guidelines state that regardless of the presence or absence of intracranial hemorrhage, acute-phase CVST can be managed with anticoagulation therapy, as demonstrated by the recommended B-level evidence.⁸

Conversely, several studies have reported good clinical outcomes of endovascular treatment with anticoagulation for patients with CVST, although there has been no high-level RCT-based evidence. There are currently two main strategies for recanalization to treat CVST: selective thrombolysis, whereby a microcatheter is introduced into the occluded segment and urokinase⁹ or rt-PA¹⁰ is injected locally; and mechanical thrombectomy, whereby blood clotting is disrupted using a percutaneous transluminal angioplasty balloon,¹¹ rheolytic catheter¹⁰ and stent.^12,13

Stent placement for acute CVST in the SSS has two important considerations. First, a good candidate for endovascular treatment usually has very long thrombosed lesions, which makes a suitable position for stent placement difficult to determine. However, in venous sinus stenosis/occlusion observed in idiopathic intracranial hypertension or dural arteriovenous fistula, identifying the target is easy. In fact, the technical success of stent placement for venous sinus steno-occlusion in the transverse sinus, sigmoid sinus and jugular vein has been reported.^14,15 We placed a stent at the distal end of the thrombus and, after ensuring that recanalization had been obtained, placed additional stents until recanalization was confirmed. These procedures enabled us to place a minimum number of stents precisely in the targeted area.

The second issue concerns the difficulty of introducing a stent into the SSS, the most distal part of the venous structure. We found only one case report, by Ohara et al.,¹⁶ in which a stent was placed in the SSS. Specifically, a Carotid WALLSTENT™ (Boston Scientific, Natick, MA, USA) was used with a 5-F delivery system to support transarterial embolization of the dural arteriovenous fistulas.

However, we used an intracranial stent (ENTERPRISE VRD) usually used to support embolization of wide-neck aneurysms that can be easily delivered using a thinner, 2.3-F catheter such as the PROWLER SELECT Plus. We were thus able to introduce the catheter easily and place the stent precisely at the distal part of the SSS, where placement at the intended site is usually difficult. Although there are two reported cases of stent placement for CVST, both were chronic cases (one being idiopathic intracranial hypertension and the other a dural arteriovenous fistula), and carotid rather than intracranial stents were placed in the SSS.^12,13

A multi-facility collaborative study conducted in accordance with the International Study on Cerebral Vein and Dural Sinus Thrombosis indicated that age 37 years or older, male sex, the presence of a mental disorder, disturbance of consciousness (GCS <9), deep vein thrombosis, intracranial hemorrhage, malignant tumor and central nervous system infection were associated with poor prognosis.¹⁷ In our case 1, imaging revealed extensive occlusion of the venous sinus, and the patient had a behavioral abnormality with disturbance of consciousness in addition to bilateral subdural hematomas and notable intracranial hypertension. In case 2, extensive occlusion of the venous sinus was also observed on imaging, and the patient was older and had exhibited status epilepticus. Although endovascular treatment is not strongly recommended by guidelines on CVST, partly due to an insufficient number of cases to prove the therapeutic efficacy especially for stent placement, there are accumulating evidences that endovascular treatment can be a treatment option if CVST causes severe neurological symptoms and is refractory to other treatments. Therefore, we considered that an attempt at early recanalization using endovascular therapy in combination with anticoagulation therapy could be a therapeutic option to improve the prognosis of these patients. We made every effort to obtain recanalization with conventional methods, including attempting balloon angioplasty, thrombus aspiration and selective thrombolysis. Despite the failure of these procedures, stent placement was effective, and a good clinical outcome was achieved that has lasted approximately two years to date.

Although intracranial stent placement was effective for recanalization and resolution of clinical symptoms in patients with severe sinus thrombosis in the SSS, we do not recommend routine use of this technique. First, this is off-label use of this type of stent. Second, combination of systemic heparinization and thrombolysis using rt-PA followed by antiplatelet therapy may potentially increase the risk of bleeding. Especially in case 1, because the patient with CVST was complicated by subdural hematoma, she might have a higher risk of having a bleeding complication.

Conclusions

Intracranial stent but not carotid artery stent may be a good option for refractory acute thrombosis in the SSS.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.