Vertebral artery variations in thoracic aortic patients

Physician-modified fenestration or in situ fenestration for preservation of isolated left vertebral artery in thoracic endovascular aortic repair

Objective

To present our experience of preserving the isolated left vertebral artery (ILVA) with physician-modified fenestration (PM-F) or in situ fenestration (ISF) during thoracic endovascular aortic repair (TEVAR) for aortic pathologies involving aortic arch.

Methods

This is a single-center, retrospective, observational cohort study. Between June 2016 and December 2021, 9 patients (8 men; median age 60.0 years old) underwent TEVAR with ILVA reconstruction (PM-F, n = 6; ISF, n = 3) were identified and analyzed.

Results

The technical success rate was 100%. No early (<30 days) death occurred. No aortic rupture, major stroke or spinal cord injury was observed. The median follow up was 38.0 (rang: 1.0-66.0) months. One death occurred at 56 months, while the reason cannot be identified. No aortic rupture, major stroke or spinal cord injury was observed during follow up. No patient required reintervention. Out of the 22 successfully revascularized target vessels, 2 ILVAs were found occluded in 2 patients at 6 months and 7 months, respectively. However, these two patients were asymptomatic.

Conclusions

Our initial experience reveals that PM-F or ISF for ILVA preservation was feasible, safe, and effective during TEVAR for complex thoracic aortic pathologies. However, the patency of preserved ILVA should be improved.

Transposition of Anomalous Left Vertebral to Carotid Artery During the Management of Thoracic Aortic Dissections and Aneurysms

OBJECTIVES

Preservation of antegrade flow to the left vertebral artery is often achieved by transposition or bypass to the left subclavian artery during zone 2 thoracic endovascular aortic repair (TEVAR). An anomalous left vertebral artery (aLVA) originating directly from the aortic arch is a common arch variant with a reported incidence of 4-6%. In addition, 6-10% of vertebral arteries terminate in a posterior inferior cerebellar artery (PICA), increasing the risk of stroke if not revascularized. Few series of aLVA to carotid transposition have been reported. The aim of this study was to evaluate the outcomes of patients who underwent aLVA to carotid transposition for the management of aortic disease.

METHODS

A retrospective review of all aLVA-carotid transpositions performed for the management of thoracic aortic dissection or aneurysm at a single center from 2018 to 2021 was performed. The primary outcomes were postoperative stroke and patency of the transposed aLVA. Secondary outcomes were spinal cord ischemia, postoperative cranial nerve injury (CNI), and Horner's syndrome.

RESULTS

Seventeen patients underwent aLVA to carotid transposition as an adjunct to management of aortic disease during the study period. Most were men (14) and the mean age was 54 (±16 years). The primary indication for aortic repair was dissection in 10, aneurysm in 6, and Kommerell diverticulum in 1. Nine patients underwent zone 2 TEVAR, seven received open total arch repair and there was one attempted total endovascular arch repair which was aborted due to unfavorable anatomy. Twelve transpositions were performed prior to or concomitant with planned aortic repair due to high-risk cerebrovascular anatomy (3 PICA termination, 6 dominant aLVA, 4 intracranial left vertebral artery stenosis), and two were performed postoperatively for treatment of type II endoleak. LVA diameter ranged from 2 - 6mm (mean 3.3 mm). Mean operative time for transposition was 178 (±38) minutes, inclusive of left subclavian artery revascularization and mean estimated blood loss was 169 (±188) mL. No patients experienced 30-day postoperative spinal cord ischemia, stroke, or mortality. There were two cases of postoperative hoarseness, presumably due to recurrent laryngeal nerve palsy, both of which resolved within 4 months. There were no cases of Horner's syndrome. At follow-up (mean 306 days [6-714 days]), all transpositions were patent.

CONCLUSIONS

Vertebral-carotid transposition is a safe and effective adjunct in the management of aortic disease with anomalous origin of the LVA.

Open surgical treatment of subclavian artery pseudoaneurysm after endovascular repair: a case report

Background

Subclavian artery aneurysms are rare but may cause life-threatening complications. Surgical repair has been performed as a treatment of choice, but recently, with the development of endovascular treatment, many endovascular repairs have been performed to prevent surgical complications.

Case presentation

A patient undergoing endovascular repair with a subclavian artery aneurysm was diagnosed with a type II endoleak with an enlarged aneurysmal sac. Surgical repair was performed to remove the aneurysmal sac compressing the adjacent organs.

Conclusions

The highly mobile subclavian artery has abundant collaterals. Therefore, regular follow-up is essential for endovascular repair. Surgical repair is effective when adjacent organs are compressed by the aneurysm sac.

Transposition of Isolated Left Vertebral Artery in Hybrid Thoracic Endovascular Aortic Repair

Objectives: The aim of this study was to present our experience with the management of isolated left vertebral artery (ILVA) during complex thoracic aortic pathology treated with the hybrid thoracic endovascular aortic repair.

Methods: This is a single-center, respective cohort study. Between June 2016 and June 2020, 13 patients (12 men; median age 60 years old, range 42–72 years old) who underwent hybrid procedures were identified with ILVA in our center. Demographics, imaging features, operation details, and follow-up in these patients were collected and analyzed.

Results: In this study, all patients received the hybrid procedure, and the primary technical success rate was 100%. There were no in-hospital deaths. Complication occurred in two (15.4%) patients. One patient suffered from contrast-induced acute kidney injury (CI-AKI) and recovered before discharge. Another patient required reintervention for acute left-lower-limb ischemia, which was successfully treated using Fogarty catheter embolectomy. Immediate vagus/recurrent laryngeal never palsy, lymphocele, and chylothorax were not observed. The median duration of follow-up was 22 months (range, 13–29 months). No neurologic deficits, bypass occlusion, or ILVA occlusion or stenosis were observed during the follow-up. No aortic rupture, cerebrovascular accident, or spinal cord ischemia was observed during the follow-up period.

Conclusions: Our limited experience reveals that hybrid procedures [thoracic endovascular aortic repair (TEVAR), ILVA transposition, and left common carotid artery-left subclavian artery (LCCA-LSA) bypass] are relatively safe, feasible, and durable for the treatment of thoracic aortic pathology with ILVA. However, further technique durability and larger studies with long-term follow-up periods are warranted.

Aortic arch anomalies, embryology and their relevance in neuro-interventional surgery and stroke: A review

BACKGROUND

Congenital aortic arch anomalies are commonly encountered during neurointerventional procedures. While some anomalies are identified at an early age, many are incidentally discovered later in adulthood during endovascular evaluations or interventions. Proper understanding of the normal arch anatomy and its variants is pivotal to safely navigate normal aortic arch branches and to negotiate the catheter through anomalies during neurointerventional procedures. This is particularly relevant in the increasingly "transradial first" culture of neurointerventional surgery. Moreover, some of these anomalies have a peculiar predilection for complications including aneurysm formation, dissection, and rupture during the procedure. Therefore, an understanding of these anomalies, their underlying embryological basis and associations, and pattern of circulation will help endovascular neurosurgeons and interventional radiologists navigate with confidence and consider relevant pathologic associations that may inform risk of cerebrovascular disease.

METHODS

Here, we present a brief review of the basic embryology of the common anomalies of the aortic arch along with their neurological significances and discuss, through illustrative cases, the association of aortic arch anomalies with cerebral vascular pathology.

CONCLUSIONS

Understanding the aortic arch anomalies and its embryological basis is essential to safely navigate the cerebral vascular system during neurointerventional surgeries.

Radiological anatomy of the intracranial vertebral artery in a select South African cohort of patients

The intracranial segment of the vertebral artery (VA) is the unique part of the artery where the two VAs join to form a single vascular channel, viz. the basilar artery. In addition to this typical description, anatomical variations have been described; the presence of anatomical variation has been associated with some pathological processes, neurological complications, and the risk of vascular diseases in the posterior circulatory territory. We evaluated the typical anatomical features and variations of the VA4 component of the VA in a South African population to provide useful data on the prevalence of variation and morphometry of the distal VA. The study is an observational, retrospective chart review of 554 consecutive South African patients (Black, Indian, and Caucasian) who had been examined with multidetector computed tomography angiography (MDCTA) from January 2009 to September 2019. We observed various anatomical variations in the VA4 segment of the VA. We report the incidence of VA hypoplasia, hypoplastic terminal VA, and atresia. Fenestration and duplicate posterior inferior cerebellar artery (PICA) origin were also observed. The left intracranial VA was significantly larger than the right. Our study shows that anatomical variation of the intracranial VA is common in the population studied, with a total prevalence of 36.5%. Understanding the patterns of anatomical variations of the VAs will contribute significantly to the interpretation of ischemic areas and diagnosis of various diseases in the posterior circulatory territory.

Two-Stage Redo Aortic Arch Repair in a Patient With an Isolated Left Vertebral Artery

A 47-year-old male presented with an enlarging distal aortic arch false lumen 6 months status post ascending and hemiarch replacement with antegrade endograft insertion for acute type A aortic dissection complicated by lower body malperfusion. Preoperative computed tomographic angiography showed an isolated but dominant left vertebral artery. A 2-stage open surgical repair was performed. First, the left subclavian artery was transposed on the common carotid and vertebral onto the subclavian. At the second stage, a redo total arch reconstruction was done with bypass grafts taken to the innominate and left common carotid arteries. The patient did well postoperatively.

Endovascular Repair of an Aortic Arch Aneurysm in a Patient with a Hypoplastic Left Vertebral Artery Terminating into the Posterior Inferior Cerebellar Artery

We present a 76-year-old male with an aortic arch aneurysm and a hypoplastic left vertebral artery (VA). Endovascular repair with left subclavian artery (SCA) closure was planned. The right VA was dominant, while the left VA was hypoplastic, barely connected to the basilar artery, and appeared to terminate at the posterior inferior cerebellar artery (PICA). The VA sizes and flow patterns during ultrasonography confirmed these findings. Therefore, we performed endovascular repair with left SCA reconstruction to prevent ischemia of the PICA perfusion area. After the operation, he experienced no difficulty with brain perfusion.

Isolated left vertebral artery and its consequences for aortic arch repair

A left vertebral artery (LVA) originating directly from the aortic arch is the second most common supra-aortic branching anomaly. This isolated LVA can also terminate in the posterior inferior cerebellar artery without contributing to the circle of Willis, limiting treatment options, especially in cases with an incomplete circle. Here, we describe our consideration of the treatment options for a 79-year-old patient with a large distal aortic arch aneurysm combined with an isolated LVA and incomplete circle of Willis that may endanger adequate (intraoperative) cerebral perfusion.

Thoracic endovascular aortic repair in a case of grade III blunt aortic injury with aberrant vertebral artery origin

Aberrant origin of the left vertebral artery (LVA) can pose a challenge during thoracic endovascular aortic repair. We encountered such a patient who was involved in a motor vehicle accident in whom computed tomography angiography revealed a grade IIIB blunt aortic injury with an anomalous origin of the LVA distal to the origin of the left subclavian artery. On-table aortography confirmed dominance of the LVA. Hence, an open left carotid-vertebral and then left carotid-subclavian artery bypass was performed, followed by thoracic endovascular aortic repair. The patient recovered well and was discharged home 3 days later.

Transposition of the left vertebral artery during endovascular stent-graft repair of the aortic arch

OBJECTIVES

The aim of this study was to present our experience with the management of isolated left vertebral artery during hybrid aortic arch repairs with thoracic endovascular aortic repair completion.

METHODS

This is a single-center, observational, cohort study. Between January 2007 and December 2018, 9 patients (4.5%) of 200 who underwent thoracic endovascular aortic repair were identified with isolated left vertebral artery. The isolated left vertebral artery was the dominant vertebral artery in 4 cases and entered the Circle of Willis to form the basilar artery in all cases. Isolated left vertebral artery transposition was performed in 2 patients during open ascending/arch repair before thoracic endovascular aortic repair completion. In 4 patients, isolated left vertebral artery transposition was performed concomitant with carotid-subclavian bypass during thoracic endovascular aortic repair completion ("zone 2" thoracic endovascular aortic repair). Primary outcomes were early (<30 days) and late survival, freedom from aortic-related mortality, and isolated left vertebral artery patency.

RESULTS

Primary technical success was achieved in all cases. Isolated left vertebral artery-related complication occurred in 1 patient (Horner syndrome). Immediate thrombosis, vagus/recurrent laryngeal nerve palsy, lymphocele, and chylothorax were never observed. Postoperative cerebrovascular accident or spinal cord injury was not observed. Median follow-up was 15 months (range, 3-72). We did not observe aortic-related mortality during the follow-up. Aortic-related intervention was never required. Both isolated left vertebral artery and carotid-subclavian bypass are still patent in all patients with no sign of anastomotic pseudoaneurysm or stenosis.

CONCLUSIONS

Although isolated left vertebral artery is not a frequent occurrence, it is not so rare. It may pose additional difficulties during hybrid aortic arch surgical repairs, but isolated left vertebral artery transposition was feasible, safe, and a durable reconstruction.

Safety of perioperative cerebral oxygen saturation during debranching in patients with incomplete circle of Willis

OBJECTIVES

The consequences of common carotid artery (CCA) cross-clamping during debranching before thoracic endovascular aortic repair are unclear. We examined the safety of a simple CCA cross-clamping procedure under regional cerebral oxygen saturation monitoring (rSO2) in patients with a complete or incomplete circle of Willis (CoW) anatomy.

METHODS

Twenty-eight patients with thoracic aneurysm underwent elective debranching thoracic endovascular aortic repair with bilateral frontal rSO2 monitoring at our institution between January 2012 and October 2015. Before CCA cross-clamping, we maintained a systemic mean arterial pressure of >100 mm Hg with a vasopressor. We recorded the bilateral frontal rSO2 before, during and after CCA cross-clamping.

RESULTS

The CoW was incomplete in 11 (39.3%) patients. Of these, 6 patients had a complication of ischaemic potential. The left frontal rSO2 was <50% in 3 patients but did not fall below 40%. Compared with baseline values (mean ± SD 64.6 ± 6.9%), the left frontal rSO2 showed no significant change perioperatively in those with a complete CoW on the left CCA cross-clamping (during: 61.0 ± 7.9%, P = 0.17; after: 65.1 ± 5.9%, P = 0.09). In patients with an incomplete CoW with ischaemic potential, the left frontal rSO2 did not change significantly after cross-clamping (baseline: 59.8 ± 3.2%, during: 55.5 ± 5.0%; P = 0.10) but increased significantly on declamping (62.8 ± 4.5%, P = 0.023). The extent of the changes in the mean left frontal rSO2 on clamping and declamping decreased and increased by 7.3% and 11.7%, respectively, in patients with an incomplete CoW, when compared with 5.3% and 5.8% in those with a complete CoW (P = 0.65 and 0.31, respectively). No perioperative cerebrovascular events were observed.

CONCLUSIONS

Simple CCA cross-clamping during debranching was safe when arterial pressure was supported and rSO2 was monitored, even with an incomplete CoW and ischaemic potential.

A systematic classification of the vertebral artery variable origin: clinical and surgical implications

Several congenital anomalies regarding the right (RVA) and left (LVA) vertebral artery have been described. The current paper aims to perform a systematic literature review of the variable vertebral artery (VA) origin from the aortic arch (AOA) and its branches. The incidence of these variants and the ensuing AOA branching pattern are highlighted. Atypical origin cases were found more commonly unilaterally, while LVA presented the majority of the aberrancies. The LVA emersion from the AOA (3.6%) and the RVA from the right common carotid artery (RCCA) (0.14%) were the commonest origin variations. Aberrant RVA origin as last branch of the AOA is very rare. Eighteen cases (0.12%) with an aberrant right subclavian artery (ARSCA) were found. Among them, the RVA originated from the RCCA and right subclavian artery in 94.4 and 5.6%, respectively. Sporadic cases had an AOA origin bilaterally; RVA and LVA had a double origin in 0.027 and 0.11%, respectively. A dual origin was detected in 0.0069%, bilaterally. The atypical VA origin may coexist with: (i) an ARSCA, (ii) a common origin of brachiocephalic artery and left common carotid artery (the misnomer bovine arch) and (iii) a bicarotid trunk. The aberrant VA origin favors hemodynamic alterations, predisposing to cerebrovascular disorders and intracranial aneurysm formation. Detailed information of VA variants is crucial for both endovascular interventionists and diagnostic radiologists involved in the treatment of patients with cerebrovascular disease. Such information may prove useful to minimize the risk of VA injury in several procedures.

Supraclavicular transposition of aberrant left vertebral artery for hybrid treatment of aortic arch aneurysm: a case report

Background

Vertebral artery variations are common in thoracic aortic patients. If patients have the aberrant left vertebral artery, the more difficult to determine the treatment modality.

Case presentation

We report the case of a 63-year-old man with an aberrant left vertebral artery originating from an aneurysmal aortic arch. The patient underwent a successful hybrid thoracic endovascular aortic repair after aortic arch debranching and transposition of the aberrant left vertebral artery to the left common carotid artery through a supraclavicular incision without sternotomy.

Conclusions

The aberrant left vertebral artery originating from the aortic arch can be safely transposed to the left common carotid artery through a supraclavicular approach.

Facilitation of bilateral selective antegrade cerebral perfusion with axillary cannulation and retrograde coronary sinus catheter

Over the past several decades, techniques for surgery of the aortic arch have undergone significant evolution. In addition, there have been refinements in the mechanism of cerebral protection utilized intraoperatively. However, significant practice variations in the strategy of antegrade selective cerebral perfusion continue to persist. Here, we describe a simple and easily reproducible technique for selective antegrade cerebral perfusion, utilizing axillary cannulation and retrograde coronary sinus balloon catheters.