Immediate Angioscopic Investigation After Cerebral Artery Thrombectomy Revealed Aortogenic Cerebral Infarction

Abstract

Background

Aortogenic embolism is one of the causes of embolic stroke of undetermined source, which can be difficult to diagnose.

Methods

We present the case of a 74‐year‐old male patient with a history of Bentall surgery and thoracic endovascular aortic repair who was transported to our hospital with sudden‐onset right‐sided hemiplegia and total aphasia. Magnetic resonance imaging revealed an acute left middle cerebral artery occlusion. Subsequently, an emergency mechanical thrombectomy was performed, through which the left middle cerebral artery was partially reperfused. We immediately investigated the aorta using an angioscopy.

Results

The angioscopy revealed a thrombus attached to an artificial blood vessel of the aorta close to the origin of the left common carotid artery. Because no other source of the embolus could be identified using electrocardiography or ultrasound, we diagnosed an aortogenic cerebral infarction by combining these findings with the pathological findings of the collected thrombus.

Conclusions

This is the first report that aortogenic cerebral infarction could be diagnosed using an angioscopy immediately after a cerebral artery thrombectomy.

Nonstandard Abbreviation and Acronym

CCA

common carotid artery

MCA

middle cerebral artery

ESUS

embolic stroke of undetermined source

Clinical Perspective

• Aortogenic embolism should always be considered as one of the causes of cerebral embolism.

• Aortic evaluation should be performed immediately when aortogenic embolism is suspected.

• An angioscopy is a valuable device in the search for embolic sources, which can be evaluated macroscopically.

Aortogenic embolism is one of the causes of embolic stroke of undetermined source (ESUS). ¹ However, it is difficult to diagnose a cerebral infarction as being aortogenic. To the best of our knowledge, this is the first report demonstrating that aortogenic cerebral infarction could be diagnosed by an angioscopy immediately after cerebral artery thrombectomy.

Case Report

A 74‐year‐old male patient with a history of Bentall surgery and thoracic endovascular aortic repair attributable to thoracic aortic aneurysm and aortic regurgitation presented at our hospital 1 hour after the onset of sudden right‐sided hemiplegia and total aphasia. He had no history of atrial fibrillation (AF). Magnetic resonance imaging revealed acute cerebral ischemia in the left hemisphere (Figure 1A) and occlusion of the left middle cerebral artery (MCA) (Figure 1B). An emergent left cerebral angiography confirmed the occlusion of the proximal M1 portion of the left MCA (Figure 2A).

Figure 1.

MRI and MRA images.

A, Diffusion‐weighted imaging demonstrating ischemia in the left cerebrum. B, Magnetic resonance angiography showing occlusion of the left middle cerebral artery.

Figure 2.

Mechanical thrombectomy.

A, Left cerebral angiography showing the occlusion of the proximal M1 portion of the left middle cerebral artery. B, Left common carotid artery diverging sharply from the aorta. C, Partially reperfused left middle cerebral artery.

We immediately performed mechanical thrombectomy using an aspiration catheter and a stent retriever. Small red thrombi were collected; however, it was difficult to approach the lesion because the left common carotid artery (CCA) diverged sharply from the aorta (Figure 2B), and only partial reperfusion of the MCA could be achieved (Figure 2C).

No stenosis of the carotid and proximal intracranial arteries was found, and the ECG did not reveal AF. Therefore, we considered the cause of ESUS, and an angioscopy was performed immediately to investigate the source of the embolism. After 6F Ikari Left 3.5 100 cm (Fiber Tech Co Ltd, Tokyo, Japan) as a guiding catheter and 4F MK40BG0.39E STA 135 cm (InterTec Medicals Co Ltd, Osaka, Japan) as a probing catheter were placed at the ascending aorta close to the origin of the left CCA, VISIBLE (Fiber Tech Co Ltd) was used as an angioscopy, and low‐molecular‐weight dextran was dual infused from both catheters. ² Angioscopy revealed red thrombi attached to an artificial blood vessel of the aorta close to the origin of the left CCA (Figure 3).

Figure 3.

Angioscopic investigation.

A, The position of the tip of the angioscopy (white arrowheads). B and C, Red thrombi (black arrowheads) attached to an artificial blood vessel. D, Normal image of an artificial blood vessel.

Subsequently, a transthoracic echocardiography showed no findings of an obvious thrombus. Next, a transesophageal echocardiography was conducted 2 days later, after the patient's general condition had stabilized, which reconfirmed the absence of thrombus in the left atrial appendage, left atrium, and left ventricle. No foramen ovale patency was also observed. In addition, AF could not be identified by continuous ECG monitoring. A histopathological examination of the removed thrombus demonstrated a fresh thrombus without atheroma (Figure 4). This led to the diagnosis of aortogenic embolic stroke as a cause of cerebral infarction. The anticoagulant dose was adjusted, and the cerebral infarction did not recur subsequently. The aphasia and right‐sided hemiplegia improved gradually, and the patient was transferred to a rehabilitation hospital 2 weeks after the operation.

Figure 4.

Histopathological examination of the removed thrombus.

A, Gross appearance of the red thrombus. B, Hematoxylin and eosin staining displaying the thrombus, which is mostly occupied by red blood cells.

Discussion

There has been only one prior report to date describing use of angioscopy to diagnose an aortogenic cause of a cerebral infarction. Higuchi et al first performed a conventional magnetic resonance angiography and transesophageal echocardiography to search for the cause of cerebral infarction, but the source of the embolism was not found. ³ The patient was finally diagnosed with an aortogenic embolism by an angioscopy that was subsequently performed; however, because the cerebral thrombus itself was not collected, it is difficult to determine whether it was a true aortogenic cerebral infarction. In our case, ESUS was suspected preoperatively because the patient had no history of AF, no AF was detected on the ECG, and no stenosis was detected in the carotid and proximal intracranial arteries. Following mechanical thrombectomy, we immediately performed an angioscopic aortic examination. The advantages of performing immediate angioscopic surveillance are, of course, that it is possible to immediately determine whether the cause of stroke is aortogenic and that there is no need to perform a new puncture, which reduces the burden on the patient. The disadvantage of the procedure is that it takes additional time and requires more preparation.

This study had some limitations. Because an ultrasound scan of the carotid artery and transthoracic and transesophageal echocardiography were performed 2 days after the operation, the embolic source might have already disappeared. Furthermore, paroxysmal AF could not be completely excluded. Therefore, an insertable cardiac monitor is considered necessary to increase the AF detection rate.

Conclusions

Aortogenic embolisms should always be considered one of the causes of cerebral infarction. Therefore, when an aortogenic embolism is suspected, aortic evaluation should be performed immediately. Angioscopy is a valuable tool in the search for embolic sources, which can be evaluated macroscopically.

Author Contributions

All the authors contributed to the work described in this article. Drs Fukutome and Shiba conceived and designed the experiment. All authors were involved in the clinical management of the patient and revised the article. Drs Fukutome and Shiba drafted the article. Drs Aketa, Motoyama, Hirayama, and Higuchi supervised and coordinated the study and the article.

Informed Consent

Informed consent from the patient was obtained for this case.

Sources of Funding

None.

Disclosures

None.