Dissecting aneurysms of the vertebral artery--angiographic patterns at the dissecting site on balloon test occlusion

Left subclavian artery revascularization is associated with less neurologic injury after endovascular repair of acute type B aortic dissection

OBJECTIVE

The aim of this study was to analyze patients with acute type B aortic dissection (aTBAD) requiring thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) coverage to determine whether LSA revascularization decreased the risk of neurologic complications.

METHODS

The national Vascular Quality Initiative TEVAR module was queried for all procedures performed between 2014 and 2021. Patients presenting with aortic aneurysms or aortic ruptures were excluded from the analysis. Patients were divided into two groups according to whether their LSA was revascularized (prior to or during TEVAR) or not. Univariate followed by multivariate analysis was used to account for possible confounders and evaluate the association of LSA revascularization with the primary outcome of neurologic injury (stroke or spinal cord ischemia).

RESULTS

Among patients who had TEVAR for aTBAD, 501 patients had the LSA covered. The LSA was revascularized prior to or concomitant with TEVAR in 28% of these patients (n = 139). Average age was 57 years, and 73% (n = 366) were male. Neurologic injury developed in 88 patients (18%). On univariate analysis, patients who had their LSA revascularized were significantly less likely to develop neurologic injury (10% vs 20%; P < .01). This association persisted after accounting for potential confounders (odds ratio, 0.4; P = .02). No significant difference was seen when comparing 30-day or 1-year mortality between patients who had LSA revascularization and those who did not. Follow-up averaged 1.9 years (range, 0-8.1 years). Long-term survival did not differ between the two groups on Kaplan-Meier analysis.

CONCLUSIONS

In this study of patients with aTBAD who underwent LSA coverage during TEVAR, the addition of a LSA revascularization procedure was associated with a significantly lower incidence of neurological injury including spinal cord ischemia and/or stroke.

Safety of Left Subclavian Artery Selective Coverage without Revascularization in Thoracic Endovascular Aortic Repair for Type B Aortic Dissections

PURPOSE

Whether to proceed left subclavian artery (LSA) revascularization in patients with LSA coverage due to insufficient proximal landing zone (PLZ) during thoracic endovascular aortic repair (TEVAR) remains controversial.

METHODS

A total of 903 patients who received TEVAR were retrospectively analyzed. LSA could be covered if the PLZ was less than 15 mm accompanied with 1) a dominant or balanced right vertebral artery, 2) a complete circle of Willis, and 3) a left vertebral artery with a diameter ≥3 mm and without severe stenosis.

RESULTS

LSA selective coverage was necessary for 35.0% (316/903) of the patients to extend the PLZ. Patients presented with weakness, pain, cooling and discoloration of the left upper extremity (LUE), and pulselessness of the left brachial artery were more in the LSA-covered group. The ischemia of LUE occurred more often in patients with LSA covered completely than in those with LSA covered partially. Functional arm status showed no significant difference in the arm, shoulder, and hand questionnaire scores at 12 months postoperative between the LSA-covered group and LSA-uncovered group, or between the LSA-covered completely group and LSA-covered partially group.

CONCLUSION

It was safe to cover the LSA origin without revascularization if the PLZ was less than 15 mm accompanied with careful evaluation (description in method).

Atypical intracranial aneurysms: spectrum of imaging findings in computed tomography and magnetic resonance imaging

We aim to describe demographics, clinical presentation, and spectrum of CT and MRI features suggestive of atypical intracranial aneurysms. The imaging protocols used for the diagnosis of intracranial aneurysms were thoroughly reviewed, including different CT and MRI protocols. We classified atypical aneurysms according to their location, size, clinical presentation, and specific imaging features. Dissecting aneurysms are one of the causes of stroke in young adults that may show intimal flap and double lumen. Traumatic intracranial aneurysms are a rare but serious complication of head injuries. Mycotic aneurysms are small and multiple at distal branch points with a high risk of rupture. Aneurysms with vasculitis are fusiform with a wide neck at a non-branch point that may be associated with vessel wall enhancement. Atherosclerotic aneurysms are usually large fusiform that affect large arteries. Oncotic aneurysms are relatively rare. They were reported to occur in patients with left atrial myxoma. Our study represented a wide spectrum of atypical intracranial aneurysms with their detailed diagnostic imaging findings on MRI and CT including newly introduced MRI sequences, which greatly influenced early diagnosis and timely management.

Early Outcomes of Left Subclavian Artery Revascularization Using Castor Single-Branched Stent-Graft in the Treatment of Type B Aortic Dissection or Intramural Hematoma

Background: More evidence was required to guide the management of left subclavian artery (LSA) during thoracic endovascular aortic repair (TEVAR). The present study aimed to compare the outcomes of LSA coverage with LSA revascularization. Another purpose of this study was to share our experience of LSA revascularization with castor single-branched stent-graft.

Methods: From January 2016 to December 2019, 134 patients with type B aortic dissection (TBAD) or intramural hematoma (IMH) were enrolled and divided into two groups, the LSA-covered group (n = 61) and the LSA-revascularized group (with castor single-branched stent-graft, n = 73). The results, such as in-hospital and 30-day mortality, stroke, paraplegia, left arm ischemia, operation time, endoleak, were compared between the two groups.

Results: The incidence of 30-day stroke in the LSA-covered group (8.2%) was significantly higher compared with the LSA-revascularized group (0%, P = 0.018). 30-day ischemia of left arm occurred in more patients in the LSA-covered group (11.5%, P = 0.003). No statistical difference was found in the incidences of paraplegia, endoleak, in-hospital mortality, and 30-day mortality.

Conclusions: LSA should be revascularized during TEVAR to reduce the incidences of stroke and left arm ischemia. Castor single-branched stent-graft was feasible and safe for treating TBAD or IMH.

Management of the vertebral artery during thoracic endovascular aortic repair with coverage of the left subclavian artery

BACKGROUND

The application of thoracic endovascular aortic repair (TEVAR), a minimally invasive operation, in the aortic arch has been a challenge of cardiovascular surgery in recent years. This study aimed to investigate management of the vertebral artery with coverage of the left subclavian artery (LSA) during TEVAR.

METHODS

From January 2007 to September 2014 in the Department of Cardiothoracic Surgery at Wuhan General Hospital of Guangzhou Military Region, 160 patients underwent LSA closure or partial coverage during TEVAR of an aortic lesion near the LSA. The vertebral artery treatment, the reason for the surgical approach selection, and the prognosis were analyzed.

RESULTS

In 94 patients with partial LSA coverage during TEVAR, no treatment was provided for the vertebral arteries, revealing blood flow of the left vertebral artery forward into the skull after surgery. For 66 patients with full LSA coverage (closure) during TEVAR, right carotid artery-left common carotid artery bypass surgery was performed before TEVAR in ten patients, without any treatment for the vertebral artery, showing reverse blood flow of the left vertebral artery after surgery. Left common carotid artery-LSA bypass surgery was performed before TEVAR in four patients; right common carotid artery-left common carotid artery-LSA bypass surgery was performed before TEVAR in three cases, and 6 out of these 7 patients underwent proximal LSA ligation, showing no obvious blood flow in the left vertebral artery. The closure of the LSA aortic arch opening using an occluder was performed in one patient, preserving the forward blood flow in the left vertebral artery. Among the 160 patients in this study, postoperative recurrent laryngeal nerve injury occurred in one patient after right common carotid artery-left common carotid artery-LSA bypass surgery, and the remaining 159 patients had no significant severe complications or death within 1 postoperative month.

CONCLUSIONS

Appropriate management of the aortic arch branch vessels may expand the application of TEVAR to the aortic arch and reduce complications, especially for high-risk patients who have a difficult time tolerating thoracotomy.

Pathomorphometry of ruptured intracranial vertebral arterial dissection: adventitial rupture, dilated lesion, intimal tear, and medial defect

OBJECT

Subarachnoid hemorrhage (SAH) due to ruptured intracranial vertebral artery (VA) dissection is a life-threatening disease. Angiographic and symptomatic prognostic factors for rupture and rerupture have been investigated, but the pathological characteristics have not been fully investigated. The authors aimed to investigate these features by performing a pathomorphometic study of ruptured intracranial VA dissections.

METHODS

This study included 50 administrative autopsy cases of fatal SAH due to ruptured intracranial VA dissection among 517 fatal nontraumatic cases of SAH occurring between March 2003 and May 2011. Pathomorphometry was performed using serial 5-μm histological cross-sections with elastica van Gieson staining from each 0.2-mm segment around the ruptured intracranial VA. The longitudinal lengths of 4 types of vascular lesions-adventitial ruptures, dilated lesions where the internal elastic lamina (IEL) was ruptured with adventitial extension, intimal tears where the IEL was ruptured, and medial defects-were calculated based on the numbers of the slides in which these lesions were continuously detected (minimum 2 adjoining slides). The distance from the vertebrobasilar junction to the center of adventitial rupture was also calculated in 37 cases.

RESULTS

All cases showed one adventitial rupture with a mean length of about 1.9±1.1 mm. The center of the adventitial rupture was located 5.0-26.8 mm (mean 14.6±5.5 mm) from the intracranial VA bifurcation. Adventitial ruptures existed in the centers of dilated lesions, where the adventitia was highly extended. Other vascular lesions were serially observed surrounding the adventitial rupture. The mean lengths of dilated lesions, intimal tears, and medial defects were 9.4±4.8 mm, 13.2±6.3 mm, and 15.6±7.2 mm, respectively. The lengths between proximal lesions and distal lesions from the center of the adventitial rupture for both medial defects and intimal tears were significantly longer at proximal lesions than at distal ones (chi-square test, p<0.01).

CONCLUSIONS

Every ruptured intracranial VA dissection has a single point of adventitial rupture where the adventitia was maximally extended, so dilation appears to be a valuable predictive factor for hemorrhagic intracranial VA dissections. The adventitial ruptures were as small as 2 mm in length, and clinically detectable dilated lesions were about 9 mm in length. However, vascular vulnerability caused by IEL ruptures and medial defects existed more widely across a length of VA of 1.3-1.5 cm. Comparatively broader protection of the intracranial VA than the clinically detected area of dissection might be desirable to prevent rebleeding. Broader protection of proximal lesions than distal lesions might be effective from the viewpoint of site distribution of vascular lesions and blood flow alteration to the pseudolumen caused by the dissecting hematoma. Medial defects are the most widely seen lesions among the 4 types of vascular lesions studied. Medial degenerative disease, known as segmental arterial mediolysis, is suspected in the pathogenesis of intracranial VA dissections.