Spontaneous internal carotid artery pseudoaneurysm complicated with ischemic stroke in a young man: A case report and review of literature.

BACKGROUND: Carotid artery pseudoaneurysm (PSA) is infrequently encountered in clinical settings. Internal carotid artery (ICA) PSA complicated with ischemic stroke is rare. PSAs are typically caused by iatrogenic injury, trauma, or infection. The underlying mechanisms of spontaneous PSA formation are not well characterized. We report a healthy young man who presented with stroke as a complication of spontaneous PSA of the left ICA. CASE
SUMMARY: A 30-year-old man working as a ceiling decoration worker was hospitalized due to sudden-onset speech disorder and right lower extremity weakness. Medical history was unremarkable. Brain computed tomography revealed ischemic stroke. Digital subtraction angiography showed a left ICA PSA with mild stenosis. The patient was conservatively managed with oral anticoagulation and antiplatelet therapy. He recovered well and was discharged. The patient was in good condition during follow-up.
CONCLUSION: The occupational history of patient should be taken into consideration while evaluating the etiology of spontaneous ICA PSA in young people with stroke. ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.

Core Tip: In a previously healthy youngster with stroke, it is counterintuitive to make a connection between stroke and pseudoaneurysm (PSA), especially if there is no obvious cause. To best of our knowledge, this is the first report of spontaneous carotid artery PSA with stroke in a young adult. This case report may provide insights for diagnosis of carotid artery PSA in youngsters. Conservative therapy is a viable alternative for young patients with small carotid PSA.

INTRODUCTION

Arterial wall has a three-layered structure comprising of intima, media, and adventitia[1]. Rupture of the arterial wall may occur due to several reasons, such as iatrogenic injury, trauma, infection, or tumor invasion[2]. Disruption of the arterial wall following injury leads to formation of hematoma adjacent to the artery; subsequent proliferation of peripheral fibroblasts may result in encapsulation and organization of the hematoma leading to the formation of pseudoaneurysm (PSA)[3]. A previous study has shown that PSA formation is the most common complication of endovascular intervention with the incidence rates ranging from 0.7% to 6.25%. Femoral arteries and cardiovascular is the most common site of formation of PSA[4]. Traumatic internal carotid artery (ICA) PSA is a rare entity, with an incidence of approximately 9% in cases with head and neck trauma[5]. The clinical manifestations depend on the size, site, and etiology of the PSAs; however, the development of PSA can cause severe complications such as rupture, stroke, or asphyxia[6,7]. Digital subtraction angiography (DSA) has a high sensitivity and specificity for the diagnosis of ICA PSA and is considered as the diagnostic gold standard of PSA[8].

In this case report, we describe a case of a 30-year-old male who suffered speech disorders and right lower extremity weakness and review the previously reported cases.

CASE PRESENTATION

Chief complaints

A 30-year-old man was admitted to the Neurology department of our hospital because of the chief complaints of speech disorder and right lower extremity weakness five days ago.

History of present illness

Five days ago, the patient developed sudden-onset speech disorder and right lower extremity weakness at work and was admitted to a local hospital. The condition of the patient showed gradual improvement after administration of thrombolytic treatment. The etiology of stroke was still unknown. In order to seek more comprehensive diagnosis and treatment, the patient was referred to the Neurology department of our hospital.

History of past illness

The patient had no history of hypertension, diabetes, or coronary artery disease. Furthermore, there was no history of acute trauma or iatrogenic injury.

Personal and family history

The patient was a ceiling decoration worker. He had no history of smoking and alcohol consumption. Personal and family history was unremarkable. There was no family history of connective tissue disease, such as Marfan syndrome.

Physical examination

On physical examination, the patient was found to have a hemiparetic gait. The muscle strength of right upper and lower limbs was grade 4 and the light touch sensation was attenuated on the right side. Babinski sign was found in the sole of his right foot. Other physical findings were unremarkable.

Laboratory examinations

Routine blood parameters were as follows: Leukocyte count 11.37 × 109/L; platelet count 344 × 109/L; neutrophils 84.9%; plasma fibrinogen 4.12 g/L; lactic dehydrogenase 287 U/L. Renal function and liver function tests were normal.

Imaging examinations

Cerebral computed tomography showed low-density foci in the left frontotemporal and centroparietal regions, which were indicative of left ischemic stroke. Ultrasonography of the carotid arteries exhibited a mixed echogenic mass at the origin of the left ICA (Figure 1). Computed tomography angiography (CTA) revealed a nodular mass with mural thrombus in continuity with the adjacent left ICA lumen; the size of the mass was approximately 10 mm × 7 mm (Figure 2). DSA indicated a PSA at the origin of the left ICA with mild stenosis.

Figure 1

Ultrasonography and contrast-enhanced ultrasound of the carotid artery. A: Conventional carotid artery ultrasonography showing a connection of the mass with the left internal carotid artery (ICA); B: Contrast-enhanced ultrasound of the carotid artery showing contrast agent filling in the distended area of the left ICA, but no enhancement in the low echo area of the mural.

Figure 2

Left internal carotid artery pseudoaneurysm with acute ischemic stroke. A: Computed tomography (CT) angiography reconstruction shows a nodular mass with mural thrombus in continuity with the adjacent left internal carotid artery lumen; B: Digital subtraction angiography indicates a pseudoaneurysm at the origin of the left internal carotid artery with mild stenosis; C: Cerebral CT showing an area of low-density foci in the left frontotemporal and centroparietal regions, which indicates left ischemic stroke.

FINAL DIAGNOSIS

Left ICA PSA complicated with ischemic stroke.

TREATMENT

Low-dose alteplase and oral anticoagulation and antiplatelet therapy. For ischemic stroke, the local hospital evaluated the condition of patient and opted for low-dose alteplase to maintain the benefits of treatment while reducing the risk of systemic or intracerebral hemorrhage[9]. As for carotid PSA, the patient failed the ICA temporary occlusion test, which implied that his cerebral arteries could not develop sufficient cerebral collateral circulation. Therefore, we intended to use a combination of endovascular stent placement and coil embolization to treat the PSA. However, the patient refused this treatment option because of the costs and the associated risks. Therefore, he was conservatively managed with oral anticoagulation and antiplatelet therapy.

OUTCOME AND FOLLOW-UP

The patient recovered satisfactorily and was discharged from hospital on day 8. In order to prevent recurrence of ischemic stroke, he was prescribed oral aspirin for one month[9]. The patient was found to be in a good condition on follow-up evaluation performed at 3 and 6 months. Cerebral computed tomography (CTA) showed a large encephalomalacia focus in the left temporal-basal region, which indicated that the patient was at the convalescent stage of ischemic stroke. On cervical CTA, the size of PSA at the origin of the left carotid artery was significantly smaller than before, which was consistent with the results of DSA (Figure 3). However, we did not obtain further follow-up data for patients beyond 6 months.

Figure 3

Follow-up imaging examinations. A: On computed tomography angiography reconstruction, the size of pseudoaneurysm at the origin of the left carotid artery is 4 mm × 3 mm which was significantly smaller than that observed 6 mo ago; B: On digital subtraction angiography, the size of pseudoaneurysm at the origin of the left internal carotid artery is 6 mm × 5 mm, which was smaller than that observed 3 mo ago; C: Cerebral computed tomography shows a large encephalomalacia foci in the left temporal-basal region, which was consistent with the convalescent stage of ischemic stroke.

DISCUSSION

The incidence of stroke in young people has increased over the past decades, reaching 221 per 100000 by the end of 2019. Underlying cardiovascular disease is the main cause of stroke in this population, while aneurysms or PSA are not common causes of stroke[10,11]. PSA typically occurs due to iatrogenic injury, trauma, infection, and tumor invasion[3,12]. Spontaneous PSA are rare entities. Spontaneous PSA associated with stroke are exceedingly rare[13]. A comprehensive search of the literature was performed using the PubMed, Embase, Cochran Library and Web of Science databases to retrieve studies published before December 2021 (Supplementary material). In the 16 cases reviewed by us, the etiology of 5 cases (31%) was trauma[14-18] and 4 cases (25%) had iatrogenic injury[19-22], while only 2 cases (13%) were spontaneous; however, both spontaneous cases had a history of hypertension and hyperlipidemia[23,24] (Table 1). Our patient was a young adult with no personal or family history of cardiovascular disease. Moreover, there was no history of neck trauma or surgery on the neck. We speculated that the etiology was related to the nature of the patient's job. The patient worked as a ceiling decorator, whose daily work entailed prolonged extension of the neck for working on the ceiling. The prolonged neck extension may have caused damage to the wall of the ICA, which contributed to the formation of PSA. Moreover, PSAs are more prone to thrombosis due to vortex in the PSAs[25]. The patient developed sudden weakness of the right lower limb and speech disorder at work, which may be due to the hemodynamic changes at the thrombus site caused by the change in head posture. Subsequently, the thrombus embolized to the M1 segment of the left middle cerebral artery, resulting in ischemic stroke of the temporoparietal lobe[26]. Our experience suggests that carotid PSA should be considered when evaluating a patient presenting with stroke. what’s more, it is necessary to perfect the relevant examinations.

Table 1

Literature review of pseudoaneurysm with the clinical presentation of stroke

Case No.	Ref.	Year	Age	Sex	Site	Etiology	Imaging modality	Treatments	Outcome	Follow-up
1	[14]	2000	19	M	R CCA	Traumatic	CT, US, MRA, DSA	Surgical resection	REC	NA
2	[35]	2005	62	M	L INA	Infectious	US, MRI	Surgical resection	REC	1 mo
3	[19]	2007	60	M	R ICA	Iatrogenic	MRI, DSA	Endovascular stenting	REC	NA
4	[15]	2007	31	M	R ICA	Traumatic	MRI, CT, DSA	Endovascular stenting	REC	NA
5	[24]	2008	51	M	L ICA	Spontaneous	MRI, CT, DSA	Endovascular stenting	REC	NA
6	[43]	2014	71	M	L ICA	Radioactive	US, CT, MRI, DSA	Endovascular occlusion	REC	NA
7	[16]	2013	46	M	L ICA	Traumatic	CT, DSA	Endovascular stenting	REC	14 mo
8	[44]	2017	2	M	L ICA	Infectious	MRI, CT, DSA	Endovascular occlusion	REC	1 mo
9	[23]	2018	85	M	L ECA	Spontaneous	US, CT, MRI, DSA	Conservative therapy	Death	7 mo
10	[45]	2019	60	F	L ECA	Congenital	MRI, CT, DSA	Endovascular stenting	REC	NA
11	[22]	2019	45	M	L CCA	Iatrogenic	CT, CTA	NA	REC	NA
12	[20]	2019	57	F	L CCA	Iatrogenic	CT, CTA	Endovascular occlusion	REC	6 mo
13	[21]	2019	79	M	R FA	Iatrogenic	CT, MRI, CTA	Endovascular stenting	NA	NA
14	[46]	2020	53	M	SA	Infectious	CT, DSA	Conservative therapy	REC	NA
15	[17]	2020	31	F	L VA	Traumatic	CT, CTA, DSA	Conservative therapy	REC	6 mo
16	[18]	2021	35	M	L ICA	Traumatic	US, MRI, MRA	Endovascular occlusion	REC	3 mo
Present case		2022	30	M	L ICA	Spontaneous	US, CT, CTA, DSA	Conservative therapy	REC	6 mo

CCA: Common carotid artery; CT: Computed tomography; CTA: Computed tomography angiography; DSA: Digital subtraction angiography; ECA: External carotid artery; F: Female; FA: Femoral artery; ICA: Internal carotid artery; INA: Innominate artery; L: Left; M: Male; MRA: Magnetic resonance angiography; MRI: Magnetic resonance imaging; NA: Not available; R: Right; REC: Recovery; SA: Splenic artery; US: Ultrasound; VA: Vertebral artery.

Carotid ultrasonography, a noninvasive, cost-effective, and radiation-free method, is currently the first-line imaging modality for screening carotid artery PSA. Doppler sonography can help distinguish a PSA from an aneurysm and/or other cervical mass[27]. It typically shows a neck mass with the typical features of PSA, including spontaneously echogenic swirling flow in the lumen and “to-and-fro” waveforms at the neck[28]. However, the “to-and-fro” waveforms were not observed in our patient, probably because of the relatively small tumor size. Furthermore, it is difficult to directly detect an ICA PSA that is located about 20 mm above the bifurcation of the common carotid artery[29]. In our patient, although this PSA was located 17 mm above the common carotid artery bifurcation, when we found a mass in the initial part of the ICA, we performed contrast-enhanced ultrasound (CEUS) of the carotid artery. CEUS showed contrast agent filling in the distended area of the left ICA, but no enhancement in the low echo area of the mural (Video 1). This finding suggests that the combination of ultrasonography and CEUS of the carotid artery may facilitate the diagnosis of PSA located at a relatively high position. CTA can effectively depict the localization, size, and mural thrombus of PSA[30]; furthermore, CTA with 3D reconstruction maps can delineate the outer wall of PSA and its relationship with peri-PSA vascular structures, which can provide surgeons with intuitive 3D image guidance[8]. In our case, CTA reconstruction revealed a nodular mass with mural thrombus in continuity with the adjacent left ICA lumen, which was an important anatomical information. The gold standard for the diagnosis of PSA is DSA with > 99% sensitivity and 100% specificity[8,31]. Out of the 16 reported cases, DSA was used as a diagnostic method in 11 cases (69%). In the present case, angiography showed the contrast agent entering the tumor cavity along with changes in eddy currents, which indicated rupture of the left ICA wall and the formation of PSA. Furthermore, the parent artery was localized with delayed distal development, which indicated compression of ICA. Although the diagnostic performance of DSA is pretty good, it is difficult to detect PSA that is filled with thrombus at the early stage[32].

Surgery and endovascular therapy are two main treatment modalities for carotid PSA[33]. Because of the severe complications of surgery and the rapid advances in the field of endovascular intervention, endovascular therapy has emerged as the preferred treatment for carotid PSA, especially for patients with PSA who present with stroke[34]. Surgical resection is used as an alternative to endovascular treatment. In addition, the choice of endovascular therapy depends on the lesion site and the performance status of patient[14]. Out of the 16 reviewed cases, only 3 patients (13%) were treated with surgical resection[14,35]. Endovascular therapy mainly includes use of covered stent grafts, micro-coil embolization, and detachable balloon embolization[36]. Choice of endovascular treatment depends on multiple factors, mainly the site of PSA, age of patient, and intracranial collateral circulation[37]. ICA temporary occlusion test should be performed first for PSAs occurring in the extracranial ICA[38]. If the test is successful, the ICA can be permanently occluded using a detachable balloon. If the test fails, the patient can be treated with covered stent grafts and accessory micro-coil embolization[39]. Our patient failed the ICA temporary occlusion test, which indicated the lack of adequate cerebral collateral circulation. Therefore, we intended to combine endovascular stent placement and coil embolization to treat the PSA; however, the patient opted for conservative management owing to the high cost of treatment and the associated risks. At 6-mo follow-up, the patient was in a relatively good condition and cervical CTA showed significant reduction in the size of PSA. Anticoagulant and antiplatelet agents may decrease mortality related to carotid PSA; however, such conservative management alone is not recommended owing to the risk of delayed rupture of PSA of the carotid artery, which is a life-threatening condition[40]. Out of the 16 cases reviewed, only 3 patients (19%) were conservatively managed. Budincevic et al[25] reported an 85-year-old man who died after receiving conservative therapy. However, Xue et al[17] reported a 31-year-old woman who showed satisfactory outcome with conservative treatment, which is consistent with our present case. Our patient may have shown better efficacy of conservative treatment owing to the relatively small size of the aneurysm. In addition, previous studies have shown that the choice of endovascular therapy should depend on the etiology of PSAs and that endovascular therapy is not necessary for all types of PSAs[41,42]. Thus, it is important to select appropriate treatment according to the etiology. Our report may provide an alternative therapy for young patients with small carotid PSA, nevertheless, the length of follow-up in our report was relatively short, which is its limitation.

CONCLUSION

We report a young man with clinical presentation of ischemic stroke that was triggered by thrombosis of PSA. The etiology of spontaneous ICA PSA in this case remains unknown. We inferred that the etiology may be related to the characteristics of the patient's occupation. Therefore, history of trauma, infection, and occupational history should be carefully elicited in young patients with acute ischemic stroke who have no history of cardiovascular disease. DSA is the gold standard for the diagnosis of carotid PSA; however, the combination of CEUS and conventional ultrasonography of the carotid artery may facilitate the diagnosis of PSA that is located at a relatively high position. Last but not least, although endovascular therapy is the recommended treatment for carotid PSA, the treatment strategy should be personalized based on the patient characteristics. Conservative therapy may be a viable alternative for young patients with small carotid PSA.