Keywords
acute ischemic stroke - subarachnoid hemorrhage - pseudoaneurysm - mechanical thrombectomy - stent retriever - complication - vessel perforation
Introduction
Mechanical thrombectomy (MT) is safe and effective for treating acute ischemic stroke due to large vessel occlusion.[1] However, MT is associated with several procedure-related complications, which include vessel injury, embolization to a different or distant target vessel territory, access site difficulties, use of radiographic contrast, and postprocedural intracranial hemorrhage.[2] Vessel perforation is the most serious bleeding complication associated with vascular injury and can lead to disability or death. It is typically detected on angiography because of contrast extravasation or device protrusion outside the vessel. Pseudoaneurysms associated with endovascular procedures are rare but can occur after MT in cases with vessel injury.[3]
[4]
[5]
[6]
[7]
In this case report, we present a case of delayed rebleeding from a pseudoaneurysm after MT with a stent retriever confirmed by open surgery.
Case Description
An 85-year-old woman with a history of hypertension, diabetes mellitus, and atrial fibrillation was transported to the hospital via an ambulance following a traffic-related injury. The patient was not taking any antiplatelet or anticoagulant medications. Head computed tomography (CT) revealed traumatic intracranial hemorrhage ([Fig. 1]), and the patient was admitted to the neurosurgery department.
Fig. 1 Initial head computed tomography after trauma showing bilateral contusions.
A blood test on day 3 showed an elevated D-dimer level of 4.33μg/mL. On day 4, 1.5 hours after the final safety assessment, the patient had aphasia and paralysis on her right side. CT revealed no new intracranial hemorrhage or early ischemic findings ([Fig. 2A]). Brain magnetic resonance imaging revealed hyperintense areas in the left middle cerebral artery (MCA) region using diffusion-weighted imaging (DWI) ([Fig. 2B]). Magnetic resonance angiography (MRA) detected an occlusion in the distal M2 segment of the left MCA ([Fig. 2C]), indicating a cardiogenic embolism. A DWI–clinical mismatch was observed, and recanalization therapy was performed.
Fig. 2 (A) Head computed tomography showing no new intracranial hemorrhage or early ischemic findings. (B) Magnetic resonance diffusion-weighted imaging showing acute ischemic change involving the left middle cerebral artery territory. (C) Magnetic resonance angiography showing occlusion of the distal M2 portion of the left middle cerebral artery.
Endovascular Procedure
An endovascular procedure was performed under local anesthesia via femoral access. A 9-French balloon-guiding catheter was placed in the cervical portion of the left internal carotid artery. Initial angiography confirmed occlusion of the M2 segment of the left MCA ([Fig. 3A]). The occlusion was crossed using a Marksman microcatheter (Medtronic, Minneapolis, Minnesota, United States) and a CHIKAI microguidewire 0.014 200 cm (Asahi Intec, Aichi, Japan). Angiography through the microcatheter showed the distal artery to be normal, a Solitaire 4 × 20 mm stent retriever (Medtronic) was fully deployed across the occluded lesion. Considering that it would be dangerous to retrieve the stent retrieval device in the distal vessel, we resheathed the stent, but the microcatheter jumped distally ([Fig. 3B]). Angiography through the microcatheter revealed contrast leakage into the subarachnoid space ([Fig. 3C]). The diagnosis was vessel perforation caused by the microcatheter. We treated the lesion with temporary balloon occlusion for 5 minutes using a balloon guide catheter, combined with the reversal of heparin anticoagulation with protamine and a systolic blood pressure reduction to below 120 mm Hg. Serial control angiography revealed no further contrast leakage after the removal of the microcatheter ([Fig. 3D]).
Fig. 3 (A) Initial angiographic images of the left internal carotid artery (ICA) showing occlusion of the distal M2 portion of the left middle cerebral artery (MCA). (B) An angiographic image of the left ICA; the microcatheter (arrow heads) jumped distally during stent retriever resheath. (C) Angiography through the microcatheter showing contrast leakage into the subarachnoid space. (D) Left ICA angiographic images showing arrest of extravasation without recanalization of the medial vessel of the M2 segment.
Brain CT revealed a localized subarachnoid hemorrhage (SAH) in the left cerebral cortical sulci ([Fig. 4A]).
Fig. 4 (A) A computed tomography (CT) scan obtained immediately after the endovascular procedure showing subarachnoid hemorrhage (SAH). (B) A CT scan acquired 1 day following the procedure showing decreased SAH and cerebral infarction. (C) A CT scan taken 14 days after the procedure showing a massive hematoma.
Postoperative Course
The patient's neurological symptoms improved the day after the procedure. CT revealed decreased SAH and slight cerebral infarction ([Fig. 4B]). Oral apixaban (5 mg daily) was started and continued after 24 hours of the procedure. However, on the 14th postoperative day, the patient had a headache and consciousness disturbance. CT revealed a left frontal subcortical hemorrhage ([Fig. 4C]), and angiography revealed pseudoaneurysm in the M3 segment of the MCA ([Fig. 5]). A craniotomy was performed to prevent rebleeding from the pseudoaneurysm.
Fig. 5 (A) Angiographic images of the left internal carotid artery (ICA) in the arterial phase showing occlusion of the distal M2 portion of the left middle cerebral artery (MCA). (B) Angiographic images of the left ICA in the venous phase showing formation of a pseudoaneurysm (arrow). (C) Three-dimensional digital subtraction angiography obtained 14 days after the procedure showing formation of a pseudoaneurysm (arrow) in the M2 portion of the MCA.
Open Surgery
A left frontotemporal craniotomy was performed, and a branch of the superficial temporal artery (STA) was preserved for STA-MCA bypass. A thick SAH was observed in the Sylvian fissure ([Fig. 6A]). The Sylvian fissure was opened to the distal segment of M2. The hard thrombus around the artery was then removed, revealing an aneurysm in the same location as in the preoperative angiogram ([Fig. 6B]).
Fig. 6 Intraoperative photographs. (A) Thick subarachnoid hemorrhage was observed on the surface of the brain. (B, C) Indocyanine green imaging reveals a thrombosed aneurysm and avascular area. (D) The proximal vessel of the pseudoaneurysm was clipped to control blood flow. (E) The pseudoaneurysm was removed. (F) A small artery is ruptured.
Indocyanine green confirmed the absence of antegrade blood flow ([Fig. 6C]). The proximal vessel of the pseudoaneurysm was clipped to control blood flow ([Fig. 6D]).
Removal of pseudoaneurysm revealed a ruptured small artery ([Fig. 6E] and [F]). Thus, the small artery was clipped; no rebleeding occurred after surgery ([Fig. 7]). Six months later, the patient was discharged with a modified Rankin Scale score of 3, aphasia, and mild right-sided paralysis.
Fig. 7 Computed tomography after open surgery showing the clip and removal of a massive hematoma.
Discussion
In our case, delayed rebleeding from a pseudoaneurysm occurred after MT using a stent retriever. The pseudoaneurysm was treated by open surgery. Angiographic and intraoperative findings revealed a mechanism of pseudoaneurysm formation due to small artery rupture caused by catheter jumping during resheathing of the stent retriever.
In previous reports, pseudoaneurysm formation after MT has been reported in six cases, including our case, four following stent retriever usage, one following the aspiration method, and one following the stent retriever and aspiration method ([Table 1]).[3]
[4]
[5]
[6]
[7] The mechanisms were direct injury from the aspiration method or microcatheter,[3] dissection of unknown cause,[5] and avulsion of small vessels resulting from the stent retriever method.[4]
[6]
[7] Therefore, care should also be taken to avoid these complications during the procedure. Several techniques, such as partial deployment of the stent retriever and the use of a distal access catheter, have been reported to be useful for avoiding stretching.[8]
[9] In five cases, SAH occurred immediately after MT.[3]
[4]
[6]
[7] The time when a pseudoaneurysm is confirmed varies from 8 hours to 4 weeks. Five cases of pseudoaneurysm rupture[3]
[4]
[6]
[7] and one case of third nerve palsy[5] have been reported. Treatment included endovascular treatment in two cases,[3]
[5] open surgery in three cases,[4]
[6] and conservative treatment in one case.[7] Open surgery has the advantage of more complete treatment of the pseudoaneurysm and removal of the hematoma. The outcomes were poor, one patient died[7] and five patients experienced hemiparesis and aphasia.[3]
[4]
[5]
[6]
Table 1
Previous reports of pseudoaneurysm after mechanical thrombectomy
|
Author, year
|
Age/Sex
|
Occlusion site
|
Intravenous tPA
|
Thrombectomy device
|
Location of pseudoaneurysm
|
Rupture of pseudoaneurysm
|
Timing of confirmed pseudoaneurysm
|
Mechanism of pseudoaneurysm formation
|
Treatment
|
Outcome
|
|
Jeong et al, 2016
|
60/Female
|
Rt. MCA (M1)
|
No
|
Aspiration catheter
|
Rt. MCA (M1)
|
No (angiography for follow-up of cerebral vasospasm)
|
Day 15
|
Direct injury
|
EVT coil
|
Mild weakness with her left hand
|
|
Misaki et al, 2016
|
79/Female
|
Lt. MCA (M2)
|
No
|
Stent retriever
|
Lt. MCA (M2)
|
Yes
|
8 h
|
Small artery avulsion associated with vessel deviation
|
Open surgery (clipping)
clip for the injured distal M2 segment of MCA
|
NIHSS 15
|
|
Helou et al, 2019
|
57/Female
|
Lt. ICA
|
NA
|
Stent retriever and aspiration catheter
|
Left cavernous ICA
|
No (complete ptosis of the left eye with minimally reactive pupil, a third nerve palsy)
|
4 wk
|
Dissection
|
EVT
pipeline with coil
|
mRS 5
Severe aphasia and right hemiparesis
|
|
Imahori et al, 2020
|
84/Female
|
Lt. MCA (M2)
|
Yes
|
Stent retriever
|
Lt. MCA (M2)
|
Yes
|
Day 4
|
Small artery avulsion
|
Open surgery (microsurgical suturing)
|
Severe aphasia and right hemiparesis
|
|
Shim et al, 2022
|
NA (elderly patient)
|
Lt. ACA
|
Yes
|
Stent retriever
|
Acom
|
Yes
|
Day 20
|
Small artery avulsion associated with vessel deviation
|
No
|
Dead
|
|
Our case
|
83/Female
|
Lt. MCA (M2)
|
No
|
Stent retriever
|
Lt. MCA (M3)
|
Yes
|
Day 14
|
Direct injury
|
Open surgery (clipping)
Trapping for the injured distal M3 segment of MCA
|
mRS 3
Aphasia and right hemiparesis
|
Abbreviations: ACA, anterior cerebral artery; Acom, anterior communicating artery; EVT, endovascular therapy; ICA, internal carotid artery; Lt, left; MCA, middle cerebral artery; mRS, modified Rankin Scale; NA, not available; NIHSS, National Institutes of Health Stroke Scale; Rt, right; tPA, tissue plasminogen activator.
Procedure-related SAH after MT has been reported as a benign clinical feature that does not require additional surgical procedures.[2]
[10]
[11] However, if there is contrast leakage during the intervention, it is due to vessel perforation or dissection and requires treatment. The treatment of procedure-related SAH after MT with contrast medium leakage is not well known.[2]
[10]
[11] In this case, the balloon of the guiding catheter was inflated to temporarily occlude the internal carotid artery to stop the bleeding. Additionally, antihypertensive therapy and heparin reversal therapy with protamine were performed. If angiography shows contrast leakage after repeated temporary balloon occlusions, the injured artery should be sacrificed to stop the bleeding. In such cases, permanent microcatheter placement or embolization with coils or N-butyl-2-cyanoacrylate or Gelfoam may be treatment options.[12]
[13]
[14]
[15]
Recently, MT has been cautiously performed even for medium vessel occlusion.[16]
[17]
[18] Distal artery occlusion, a higher number of thrombectomy device passes, and intravenous tissue plasminogen activator use are known risk factors for SAH after MT.[19] It may increase the incidence of hemorrhagic complications.
As SAH after MT is not uncommon, we believe that any case of SAH after MT can be followed up with CT angiography (CTA) or MRA to check for pseudoaneurysm.
Conclusion
Delayed rupture of the pseudoaneurysm occurred 2 weeks after MT using a stent retriever. The pseudoaneurysm was treated with open surgery.
If SAH is observed after MT, follow-up CTA or MRA should be performed to check the pseudoaneurysm.
