Dual-Stent Retriever Thrombectomy for Extensive Dural Sinus Thrombosis

Abstract

INTRODUCTION:

First line treatment for cerebral venous thrombosis (CVT) is systemic anticoagulation. In cases with symptoms of elevated ICP, endovascular thrombectomy (EVT) is pursued. We describe two cases in which dual stent-retrievers were used for EVT.

OBJECTIVES:

The use of dual stent-retrievers has been described in arterial stroke when clot is present in the M1 artery and both M2 branches as a rescue therapy after 1 stent-retriever failed to remove the clot. We applied this same thinking to our EVT patients.

METHODS:

A 17-year-old female with imaging demonstrating occlusion of the superior sagittal sinus (SSS), dominant right transverse sinus (TS), right sigmoid sinus (SS), and upper right internal jugular vein (IJV). A 20-year-old female with an MRV noting CVT in the dominant lateral left TS, SS, and upper left IJV.

RESULTS:

Both were taken for EVT due to severity of symptoms. Two 6 mm x 40 mm stent-retrievers were deployed into the CVT and then remove with continuous aspiration with significant recanalization.

CONCLUSIONS:

The average diameter of the dural sinuses is 8 mm compared to the average size of the middle cerebral artery 3-4 mm. The largest available SR in the US is 6 mm, and the largest outer diameter of available aspiration catheters is 2-3 mm. Due to the larger size of the dural sinuses, using two SRs can result in more efficient recanalization and less radiation.

Introduction

Cerebral venous sinus thrombosis (CVST) occurs mainly in young adults and children. These potentially fatal venous clots typically present after a week of their formation. This pathology should be considered when a patient presents with a neurological deficit accompanied by a headache and doesn’t align within a vascular distribution.

The transverse dural sinuses are typically asymmetrical with approximately half the population having a dominant right transverse sinus and a quarter with symmetrical caliber¹. While unilateral occlusion of nondominant transverse sinus may be asymptomatic, occlusion of dominant transverse sinus results in a constellation of symptoms.

Initial treatment includes systemic anticoagulation for 3-6 months. In select patients who are symptomatic, with signs and symptoms due to elevated intracranial pressure (ICP), treatment with endovascular thrombectomy may be warranted. Here we describe two cases where dual stent retriever technique was used for dural sinus thrombectomy.

Case 1

History and Examination

A 17-year-old female presented to the local children’s hospital with a 3-day history of headaches, nausea, vomiting, right visual field defect, right-sided extinction dysmetria, right-sided facial droop, right- upper and lower extremity weakness, and left-sided sensory loss. Past medical history includes PCOS treated with desogestrol and spironolactone and family history includes elevated factor VIII and strokes. Magnetic resonance venography (MRV) demonstrated occlusion of the superior sagittal sinus (SSS), dominant right transverse sinus, right sigmoid sinus, and upper portion of the right internal jugular vein, with no involvement of the deep venous system. She was admitted and started on enoxaparin. After 24 h, symptoms worsened with lethargy and was transferred to our comprehensive stroke center. Upon arrival, neurologic exam was consistent with stupor.

Radiologic Findings

Extensive dural sinus thrombosis extending from the SSS to the right internal jugular vein.

Endovascular Treatment

Due to her progressive symptoms, emergent endovascular thrombectomy was performed under general endotracheal anesthesia. A 6 French 90 cm Neuron Max sheath (Penumbra Inc, Alameda, CA) was advanced over a 5 French 125 cm Vert catheter (Cook Medical, Bloomington, IN) over a 150 cm 0.035 Glide wire (Terumo Interventional Systems, Somerset, NJ) into the right jugular bulb. A Velocity microcatheter (Penumbra Inc, Alameda, CA) was advanced over a Transcend 0.014 microwire (Stryker Neurovascular, Fremont, CA) and into the middle third of the SSS. A venogram demonstrated severely diminished flow through the SSS and right transverse sinus with faint flow through the nondominant left dural sinus system. (Figure 1A). Extensive aspiration was performed through the Jet 7 Flex aspiration catheter (Penumbra Inc, Alameda, CA) (Figure 1B) with significant recanalization of the SSS with persistent clot in the right transverse and sigmoid sinuses (Figure 1C). Aspiration was performed in the transverse and sigmoid sinuses with minimal recanalization which allowed us to measure the transverse sinus diameter which was 20 mm. Given the exceptionally larger size of her transverse sinus, it was felt that aspiration alone was not sufficient due to the size of the aspiration catheter in relation to the size of the vein. Additionally, due to the length of the thrombus, the decision was made to deploy two stent-retrievers to increase the amount of clot extraction. A Solitaire 6 mm x 40 mm stent retriever (Medtronic, Minneapolis, MN) was advanced through the microcatheter and deployed into the transverse sinus clot. A second Solitaire 6 mm x 40 mm stent retriever was advanced into the clot, extending from the lateral right transverse sinus into the right sigmoid sinus (Figure 1D and 1E). After 5 min, both stent retrievers and the aspiration catheter were removed with continuous aspiration, as a unit. A follow-up venogram demonstrated partial recanalization. This maneuver was performed two additional times with further recanalization of the right transverse and sigmoid sinuses (Figure 1F). She was admitted to the neurointensive care unit and started on a heparin drip with a goal aPTT 47-92 s. The following day her exam improved and after 2 days she was nearly back to baseline with minimal right sided weakness. Four days post-op she had less severe recurrence of symptoms and repeat CT-venography demonstrated re-occlusion of the right transverse sinus. During this time there were 5 readings a sub-therapeutic aPTT. She went for repeat thrombectomy (aspiration and balloon maceration), which was successful and resulted in resolution of symptoms. Therapeutic enoxaparin was started. On post-op day 7 she had a third recurrence of less severe symptoms. She returned for thrombectomy and was treated with catheter delivered alteplase, aspiration thrombectomy, and microwire maceration. Hematology was following throughout her hospital stay and felt that her thrombosis was due to OCP rather than the elevated Factor VIII; therefore, recommended apixaban 5 mg twice daily. She was discharged on this with no recurrence of symptoms. Six-week clinic follow-up demonstrated a normal neurologic exam. A 3-month follow-up CT-venogram demonstrated persistent nearly occlusive thrombus in the right transverse and sigmoid sinuses.

Figure 1.

A: baseline venography demonstrating extensive clot burden in the dural sinuses; B: aspiration catheter in SSS; C: partial recanalization after aspiration; D: dual stent-retriever pass demonstrating different planes of stent-retrievers, indicating large diameter of dural sinus; E: second dual stent-retriever pass; F: final venogram after aspiration and stent-retriever thrombectomy.

Case 2

History and Examination

A 20-year-old female patient with a 9-day history of bilateral retroorbital and sinus headache associated with a swollen-sensation on the left neck presented from an outside hospital with endorsed blurry vision, nausea, vomiting, and photophobia. Examination showed grade 2 papilledema of the left eye, diminished sensation on left side of face, and bradycardia. A heparin drip was started for acute hypercoagulability. A lumbar puncture demonstrated an opening pressure of 53 cm H2O with temporary relief in the headache and acetazolamide was started.

Radiologic Findings

CT-venography noted a filling defect within the lateral left transverse sinus and sigmoid sinus and an MRV confirmed these findings, noting near-complete occlusive thrombus of lateral left transverse sinus, left sigmoid sinus, and upper left jugular vein.

Endovascular Treatment

The decision was made to proceed with emergent endovascular thrombectomy under general endotracheal anesthesia. A 6 F 90 cm Neuron Max sheath was advanced over a 5 F 125 cm Vert catheter over a Glidewire into the left internal jugular vein. Following this a Penumbra Jet 7 catheter was advanced over a Marksman microcatheter over an 0.014” microwire into the lateral left transverse sinus. Venography demonstrated retrograde filling of the left transverse sinus into the right dural sinus system with no flow into the left sigmoid sinus or left internal jugular vein (Figure 2A). Venography of the SSS demonstrated normal antegrade flow into the right dural sinus with no flow into the left dural sinus.

Figure 2.

A: baseline venogram demonstrating thrombus from SS to IJ vein; B: single stent- retriever pass; C: partial recanalization after first pass; D: dual stent- retrievers in IJ vein; E & F: final venography demonstrating recanalization of SS and partial recanalization of IJ.

A Solitaire 6 mm x 40 mm stent retriever was advanced through the microcatheter and deployed into the left transverse-sigmoid sinus junction, remaining open for approximately 4 min. (Figure 2B) The Jet 7 catheter was advanced to the proximal portion of the stent retriever followed by removing them as a unit with continuous aspiration through the Jet 7 catheter. Venography revealed recanalization of the left sigmoid sinus with significant luminal irregularity likely due to residual thrombus. Upon repeated thrombectomy, the left sigmoid sinus venogram demonstrated slightly improved recanalization with persistent luminal irregularity. Further, a left sigmoid sinus venogram demonstrated minimal flow through the left internal jugular vein. (Figure 2C)

A Solitaire 6 mm x 40 mm stent retriever was deployed into the left internal jugular vein, remaining open for 4 min. During this time, the Jet 7 catheter was advanced to the proximal portion of the stent retriever. The two were then removed as a unit, with continuous aspiration through the Jet 7 catheter. A subsequent left sigmoid sinus venogram demonstrated partial recanalization of the superior left internal jugular vein. A Solitaire 6 mm x 24 mm stent retriever was advanced and deployed into the left sigmoid sinus-jugular bulb junction. To attempt to improve efficiency of clot extraction, a second Solitaire 6 mm x 24 mm stent retriever was deployed, overlapping the first stent and extending inferiorly into the left internal jugular vein. Both remained open for approximately 4 min. (Figure 2D) The stent retrievers were then removed as a unit with continuous aspiration through the Jet 7 catheter. The follow-up left sigmoid sinus venogram demonstrated significantly improved flow through the left internal jugular vein.

The Jet 7 catheter was advanced into the left internal jugular vein and continuous aspiration was performed for several minutes. The final left sigmoid sinus venogram demonstrated recanalization with persistent luminal irregularity in the left internal jugular but normal antegrade flow. (Figure 2E and 2F)

The patient was discharged on acetazolamide and apixaban. On clinic follow-up they had returned to her normal baseline and near complete resolution of the papilledema.

Discussion

The 2011 American Heart Association (AHA) and American Stroke Association (ASA) guidelines recommend anticoagulation as initial treatment of CVT with intravenous heparin or low molecular weight heparin followed by oral anticoagulation, even if intracerebral hemorrhage is present (Class 2a, level of evidence B). If neurologic decline occurs, then endovascular treatment can be pursued (Class 2 b, level of evidence C)². In 2018, the Society of Neurointerventional Surgery, a leading authority in this field, provided updated guidelines on diagnosis and treatment options for CVT. Similar to the AHA/ASA guidelines, anticoagulation is recommended as the first line of treatment (class 2 A, level of evidence C) and endovascular treatment can be pursued if there is a decline in the clinical exam or the patient is comatose (Class 2B, level of evidence C). Additionally, direction on type of endovascular treatment cannot be made due to limited evidence³. The TO-ACT trial was a randomized control trial in which patients with CVT were randomized to endovascular thrombectomy (EVT) vs medical management. The study, which enrolled 67 patients total, showed no difference in outcomes between the two arms⁴.

Endovascular treatment options include stent-retriever, aspiration, balloon maceration, and Angiojet clot disruption. In our experience, a combination of stent-retriever and aspiration thrombectomy were used, which is commonly performed in acute arterial stroke. The average diameter of the dural sinuses has been reported to range from 4.1 mm to 9.4 mm⁵. Stent-retrievers are indicated as the endovascular treatment choice for anterior circulation large vessel occlusion arterial ischemic strokes (AIS) (Class 1 A) and aspiration is considered as non-inferior to stent-retrievers (Class 1B-R)⁶. Anterior circulation arteries include the internal carotid artery (ICA) and the middle cerebral artery (MCA). The average diameter of the ICA has been reported at 3.6 mm and the average diameter of the MCA has been reported at 2.7 mm to 3.59 mm^{2 7 8}. Available stent-retrievers in the US range from 3-6 mm diameter. The average outer diameters of available large bore aspiration catheters in the US ranges from 2.08-2.17 mm. The sizing of these thrombectomy devices were designed for anterior circulation arteries and not the dural sinuses. Given the discrepancy in diameter of thrombectomy devices and dural sinus diameters, full recanalization of cerebral venous thrombosis may not be possible when compared to the one pass effect in arterial ischemic stroke. This can lead to increased contrast, radiation time, and overall procedural time. Lastly, full recanalization may not be possible, as seen in our patients.

Not achieving full recanalization in CVT may not have the untoward outcomes as seen in incomplete recanalization of AIS, where persistent occlusion can result in cytotoxic edema and permanent neurologic deficits. Several case reports in the pediatric literature demonstrate reversal of vasogenic edema and good clinical and radiographic outcomes in partial recanalization of CVT^8-10. The thought that partial recanalization leads to good outcomes in CVT when compared to AIS is that decreasing the clot burden allows the body’s own mechanisms to break down clot in addition to the salient fact that these are veins and not arteries.

Though both patients were on anticoagulation, decision to proceed with endovascular thrombectomy was due to symptoms of elevated ICP. Immediately prior to EVT, the first patient was in a state of stupor. The second patient had grade 2 papilledema and a lumbar puncture opening pressure of 53 cmH2O with the concern of permanent visual disturbances. Though her right transverse and sigmoid sinuses were patent, the right side was non-dominant and had concurrent stenosis in the transverse-sigmoid sinus junction measuring 75%, which we believe contributed to her high LP opening pressure and early onset papilledema.

In our first patient, successful recanalization of the SSS was achieved with aspiration thrombectomy. Upon recognizing the true diameter of the transverse sinus to be 20 mm after aspiration alone, the decision was made to use aspiration and two, overlapping stent-retrievers to increase contact with the large thrombus. The contralateral dural sinus system measured 7-8 mm throughout its length. Due to the large discrepancy in size of the right and left dural sinus systems and repeat occlusion of the right side resulting in neurologic deterioration, our goal was to reduce the clot burden as much as possible in the dominant right side. In the second patient, successful recanalization was achieved of the sigmoid sinus but with the larger diameter and length of the internal jugular vein thrombus, the decision was made to use the same approach as the first patient. The use of dual stent-retrievers has been described in arterial stroke when clot is present in the M1 artery and both M2 branches, as a rescue therapy after 1 stent-retriever failed to remove the clot^11-15. We applied this same thinking to our 2 patients, to increase the amount of interaction between the device and the thrombus, especially considering the larger sizes of the dural sinuses and internal jugular vein. Concurrent catheter arteriography was not performed in either patient as we performed catheter venograms from the superior sagittal sinus throughout the endovascular treatment session to assess the dural sinus drainage, as we knew this was directly related to the cortical venous drainage.

Lastly, with the increase in the number of cerebral venous sinus thrombosis reports secondary to COVID-19 this technique could be an additional endovascular strategy. With the case series of CVST and thrombocytopenia after the Johnson and Johnson vaccine, anticoagulation may not be an ideal first line therapy and the dual stent-retriever technique could be used.

Conclusion

Due to the larger size of the dural sinuses, available thrombectomy devices may not be optimal, which can lead to increased attempts at recanalization and procedure time. Using two stent-retrievers, as described in our patients, can result in more efficient recanalization, less radiation, and less contrast dye.