Prevalence of Bovine Aortic Arch Variant in Patients with Aortic Dissection and its Implications in the Outcome of Patients with Acute Type B Aortic Dissection

Current Management of Uncomplicated Type B Aortic Dissection

Aortic dissection is the most common thoracic aortic emergency and is associated with significant morbidity and mortality. Initial complications are dependent on reduction of sheer stress against the aortic wall to protect against rupture and minimize progression of the aortic wall injury. In patients with dissection starting at or distal to the left subclavian artery (Stanford type B), initial management includes strict blood pressure and heart rate control with monitoring for any complications such as malperfusion, rupture, or hemodynamic instability. Following the acute dissection event, survivors are faced with the lifelong need for blood pressure control and surveillance imaging to monitor for potential aortic deterioration leading to rupture or aneurysm formation. This review will discuss the latest recommendations for current management of uncomplicated type B aortic dissection including the evolving role of endovascular therapies.

Association Between Bovine Aortic Arch Anatomy and Stroke After Thoracic Endovascular Aortic Repair

OBJECTIVE

The link between bovine aortic arch (BAA) and stroke after thoracic endovascular aortic repair (TEVAR) was investigated.

METHODS

The multicenter retrospective study included consecutive Stanford type B aortic dissection patients undergoing TEVAR from January 2019 to December 2023. A multivariable logistic regression was utilized to assess the correlation between BAA and early stroke, while a multivariable Cox regression was employed to evaluate the association between BAA and overall stroke. Kaplan-Meier curves were used to compare the freedom from overall stroke rates.

RESULTS

In total, 138 (14.3%) had a BAA and 825 (85.7%) had a standard aortic arch (SAA). Patients with a BAA showed a greater early stroke incidence (11 [8.0%] vs 25 [3.0%]; p=0.005). An independent association was found between BAA and early stroke (odds ratio, 2.009 [95% confidence interval (CI), 1.491-2.684]; p=0.012). During follow-up, a greater incidence of overall stroke was seen in patients with a BAA (15 [10.9%] vs 42 [5.1%]) (hazard ratio, 2.310 [95% CI, 1.889-2.950]; p=0.006). Moreover, the freedom from the overall stroke rate was notably lower in the BAA group (80.42% vs 88.74%) (log-rank p=0.0068). Furthermore, patients with type A BAA showed significantly lower freedom from overall stroke rates (79.48%) relative to those with type B BAA (82.09%) (log-rank p=0.0431), and the freedom from overall stroke rate for patients with BAA ≥60 years was markedly lower (63.35%) than that in those <60 years (93.51%) (log-rank p=0.004).

CONCLUSION

BAA was correlated with an increased risk of early and overall stroke following TEVAR, particularly among older and type A BAA patients.Clinical ImpactIndividualized stroke prevention protocols and efficient neuroprotective measures should be developed for patients with BAA and adequate anticoagulation should be ensured to reduce the risk of embolism during TEVAR. This population should also ensure proper needle alignment. For instance, minimize the contact between the guide wire and the aortic arch wall. Temporal-occlusion of the carotid dynamic pulse during stent release might prevent solid fragments from entering into the craniocerebral artery. Additionally, thorough CO2 or saline flushing technique can be utilized for all the stentgrafts. Furthermore, distal cerebral embolic protection devices should be conducted in patients with a BAA during TEVAR.

Endovascular single-branched stent graft to treat complicated type B aortic dissection involving aortic arch anomalies

BACKGROUND

The optimal treatment of complicated type B aortic dissection (cTBAD) involving arch anomalies remain unclear.

METHODS

We consecutively enrolled patients with cTBAD involving arch anomalies who underwent endovascular repair using a single-branched stent graft (SBSG) at our medical center between January 2020 and January 2023. The demographics, clinical manifestation, operation detail, and follow-up outcomes of these patients were retrospectively collected and analyzed.

RESULTS

A total of 16 patients (14 men; 55.8 ± 11.7 years) were enrolled, including isolated left vertebral artery (ILVA) (n = 6), aberrant right subclavian artery (ARSA) (n = 7), and right aortic arch and aberrant left subclavian artery (ALSA) with Kommerell's diverticulum (KD) (n = 3). Among them, six patients with multi-branched arch anomalies. The endovascular management strategies of patients were diverse based on their aortic morphology. The early outcome demonstrated that one patient experienced an immediate intraoperative type Ia endoleak, which was resolved by balloon dilation, and two patients exhibited bird-beak configuration. After a median of follow-up of 910 (743-1023) days, the long-term outcome revealed that two patients developed endoleak. No death, retrograde type A aortic dissection (RTAD), paraplegia, stent graft-induced new entry tear (SINE), or branch section stenosis of SBSG were observed during the follow-up.

CONCLUSION

Our limited experience suggests that endovascular repair with a SBSG appears to be a relatively safe, feasible, and effective treatment option for patients with cTBAD and arch anomalies.

A Comparative Study of Clinical and Aortic Morphological Characteristics between Bovine Aortic Arch and Normal Aortic Arch in Patients with Acute Type B Aortic Dissection

INTRODUCTION

The purpose of this study was to analyze the difference in clinical and aortic morphological features between the bovine aortic arch and normal aortic arch in patients with acute type B aortic dissection (aTBAD).

METHODS

A total of 133 patients diagnosed with aTBAD were retrospectively collected. Based on aortic arch morphology, they were divided into the bovine aortic arch group (n = 20) and the normal aortic arch group (n = 113). Aortic morphological features were assessed on computed tomographic angiography. Clinical and aortic morphological features were then compared between the bovine aortic arch and normal aortic arch groups.

RESULTS

Patients in the bovine aortic arch group were significantly younger and with higher weight and BMI than the normal aortic arch group (p < 0.001, p = 0.045, and p = 0.016, respectively). The total aortic length in the bovine aortic arch group was significantly shorter than that in the normal aortic arch group (p = 0.039). The tortuosity of descending thoracic aorta, the tortuosity of descending aorta, and the angulation of aortic arch were significantly lower in the bovine aortic arch group (p = 0.004, p = 0.015, and p = 0.023, respectively). The width of descending aorta, the height of aorta arch, and the angle of ascending aorta were significantly smaller in the bovine aortic arch group (p = 0.045, p = 0.044, and p = 0.042, respectively).

CONCLUSION

When the aTBAD occurred, patients with bovine aortic arch were prone to be younger and with higher BMI than those with normal aortic arch. The aortic curvature and the total aortic length were lower in patients with bovine aortic arch.

Partial Arch Replacement Using Common Trunk Perfusion in Type A Acute Aortic Dissection

An 80-year-old woman was referred to our hospital following a syncope. Contrast-enhanced computed tomography revealed an acute type A aortic dissection with a bovine aortic arch and an enlarged innominate artery. The dissection affected only the ascending aorta and not the common trunk, which is composed of the innominate and left common carotid arteries. Cardiopulmonary bypass was established using common trunk perfusion and vena cava drainage. Following a thorough evaluation, a surgical intervention involving the replacement of the ascending aorta and partial arch, accompanied by the excision of the dilated innominate artery, was meticulously carried out. In instances where the common trunk remains unaffected by the dissection, it presents as a viable alternative perfusion site. Therefore, opting for an approach involving the resection of the common trunk followed by the separate reconstruction of the innominate and left common carotid arteries during the replacement of the ascending aorta and partial arch may serve as a preventative measure against potential vascular events in the future.

Association of the bovine aortic arch and bicuspid aortic valve with thoracic aortic disease

BACKGROUND

Both bicuspid aortic valve (BAV) and bovine aortic arch (BA) are considered as markers of thoracic aortic disease (TAD). But the association between them is not yet clear. This study aimed to explore the potential association of BAV and BA with TAD.

METHODS

The study involved 449 participants who underwent their first aortic valve replacement in Fuwai Hospital from June 2017 to March 2018. All patients underwent multidetector computed tomography and echocardiography before surgery. The clinical characteristics were recorded to analyze the association between BAV, BA, and TAD. The univariate and multivariate logistic regression analyses were applied to identify the risk factors for TAD.

RESULTS

BA accounted for 79.8% of the arch variants and was the most common aortic arch branching variant. BAV was present in 52.6% of the patients with BA and 38.1% of the patients with normal arch (NA). Among the 185 patients in the BAV subgroup, 50 had BA and 135 had NA. No significant differences were found in BAV anatomical phenotype, aortopathy phenotype, and valve function between BA and NA. The multivariate analysis showed that the presence of BAV and male sex were the risk predictors of TAD. BA was not a risk factor for TAD in either univariate or multivariate analysis.

CONCLUSIONS

The proportion of BAV in patients with BA was significantly higher than that of NA, but the BAV phenotype and aortopathy were not related to BA. BAV was a risk factor for TAD, whereas BA was not associated with TAD.

Anatomical variation in the branching pattern of the aortic arch: a literature review

Background

Many anatomical variations of the branching pattern of the aortic arch have been documented in the literature. These find their origin in alterations to the embryological development of the arch and have significant implications for surgical and radiological interventions.

Methods

Embase and Medline database searches were carried out in June 2021 and identified 1197 articles, of which 24 were considered eligible.

Results

Twenty-eight variations were found. The prevalence of the six main variations found is as follows: normal configuration (61.2–92.59%); bovine arch type 1 (4.95–31.2%); bovine arch type 2 (0.04–24%); origin of left vertebral artery (0.17–15.3%); aberrant right subclavian artery (0.08–3.33%); thyroid ima artery (0.08–2%). Concomitant variations present in conjunction with these variations are also documented, as were other variations which could not be classified into these six groups.

Conclusions

Anatomical variations in the branching pattern of the aortic arch are present in over one-third of individuals in some populations. These are important pre- and intra-operatively during thoracic, neck and thyroid surgery. A greater effort should be employed to construct an official classification to facilitate greater understanding among clinicians.

Individualized prediction of risk of ascending aortic syndromes

Objectives

Although ascending aortic diameter changes acutely after dissection, recommendation for prophylactic surgery of thoracic aortic aneurysms rely on data from dissected aortas. In this case-control study we aim to identify risk markers for acute and chronic aortic syndromes of the ascending aorta (ACAS-AA). Furthermore, to develop a predictive model for ACAS-AA.

Methods

We collected data of 188 cases of ACAS-AA and 376 controls standardized to age- and sex of the background population. Medical history and CT-derived aortic morphology were collected. For the dependent outcome ACAS-AA, potential independent risk factors were identified by univariate logistic regression and confirmed in multivariate logistic regression. As post-dissection tubular ascending aortic diameter is prone to expand, this factor was not included in the first model. The individual calculated adjusted odds ratios were then used in ROC-curve analysis to evaluate the diagnostic accuracy of the model. To test the influence of post-ACAS-AA tubular ascending aortic diameter, this was added to the model.

Results

The following risk factors were identified as independent risk factors for ACAS-AA in multivariate analysis: bicuspid aortic valve (OR 20.41, p = 0.03), renal insufficiency (OR 2.9, p<0.01), infrarenal abdominal aortic diameter (OR 1.08, p<0.01), left common carotid artery diameter (OR 1.40, p<0.01) and aortic width (OR 1.07, p<0.01). Area under the curve was 0.88 (p<0.01). Adding post-ACAS-AA tubular ascending aortic diameter to the model, negated the association of bicuspid aortic valve, renal insufficiency, and left common carotid artery diameter. Area under the curve changed to 0.98 (p<0.01).

Conclusions

A high performing predictive model for ACAS-AA, free of ascending aortic diameter, can be achieved. Furthermore, we have identified abdominal aortic ectasia as an independent risk factor of ACAS-AA. Integration of potential biomarkers and morphologic variables, derived from undissected aortas, would probably improve the model.

Bovine Aortic Arch, A High-Risk Variant

The bovine aortic arch is a vascular variant related to an increased incidence of vascular and neurological complications. It should be ruled out in patients with vague neurological symptoms without a clear etiology. Our case is of a 72-year-old female patient who presented with a syncopal episode; the workup incidentally showed the aortic arch bovine variant with evidence of ischemic white matter disease more than expected for age. After reviewing the related literature, we suggest that this aortic variant is likely an independent risk factor for multiple vascular complications. A close follow-up is essential, and screening should be considered for symptomatic family members.

A Combined Deep Learning System for Automatic Detection of “Bovine” Aortic Arch on Computed Tomography Scans

The “bovine” aortic arch is an anatomic variant consisting in a common origin of the innominate and left carotid artery (CILCA), associated with a greater risk of thoracic aortic diseases (aneurysms and dissections), stroke, and complications after endovascular procedures. CILCA can be detected by visual assessment of computed tomography (CT) chest scans, but it is rarely reported. We developed a deep learning (DL) segmentation-plus-classification system to automatically detect CILCA based on 302 CT studies acquired at 2 centers. One model (3D U-Net) was trained from scratch (supervised by manual segmentation), validated, and tested for the automatic segmentation of the aortic arch and supra-aortic vessels. Three DL architectures (ResNet50, DenseNet-201, and SqueezeNet), pre-trained over millions of common images, were trained, validated, and tested for the automatic classification of CILCA versus non-CILCA, supervised by radiologist’s classification. The 3D U-Net-plus-DenseNet-201 was found to be the best system (Dice index 0.912); its classification performance obtained from internal, independent testing on 126 patients gave a receiver operating characteristic area under the curve of 87.0%, sensitivity 66.7%, specificity 90.5%, positive predictive value 87.5%, negative predictive value 73.1%, positive likelihood ratio 7.0, and negative likelihood ratio 0.4. In conclusion, a combined DL system applied to chest CT scans was developed and proven to be an effective tool to detect individuals with “bovine” aortic arch with a low rate of false-positive findings.

Prevalence of common origin of the innominate and left carotid artery (CILCA) or bovine arch configuration in patients with blunt aortic injury

BACKGROUND

The common origin of the innominate and left carotid artery (CILCA) have been described as a risk factor for thoracic aortic diseases (dissections and aneurysms), but its relationship with traumatic pathology of the thoracic aorta is not so well known. The aim of the present study is to describe the prevalence of CILCA among patients admitted to the hospital for high-energy polytrauma with aortic injury (BTAI) compared with a control group.

METHODS

Retrospective unicenter case-control study. Cases included all patients treated with BTAI between 1999-2020. The group of controls was patients admitted in our center for high-energy polytrauma between 2012-2017. Primary endpoint was to define the prevalence of CILCA among both groups and secondary endpoint was to measure the distance between brachiocephalic trunk (BCT) or left common carotid artery (LCCA) and left subclavian artery (LSA). Results were retrospectively reviewed by two investigators.

RESULTS

49 patients in BTAI group and 248 patients in control group. With a good concordance between investigators, 21 patients with CILCA (42.9%) in the BTAI group versus 61 CILCA (24.6%) in the control group (p=0.009). The mean distance between BCT/LCCA and LSA among the cases with CILCA was 10.09 mm (SD = 2.89) and 7.48 mm (SD = 3.65) among cases with standard aortic arch (p = 0.010).

CONCLUSIONS

In the present study we found that CILCA configuration is more prevalent in patients with BTAI and the distance to left subclavian artery is longer.

A Deep Learning-Based and Fully Automated Pipeline for Thoracic Aorta Geometric Analysis and Planning for Endovascular Repair from Computed Tomography

Feasibility assessment and planning of thoracic endovascular aortic repair (TEVAR) require computed tomography (CT)-based analysis of geometric aortic features to identify adequate landing zones (LZs) for endograft deployment. However, no consensus exists on how to take the necessary measurements from CT image data. We trained and applied a fully automated pipeline embedding a convolutional neural network (CNN), which feeds on 3D CT images to automatically segment the thoracic aorta, detects proximal landing zones (PLZs), and quantifies geometric features that are relevant for TEVAR planning. For 465 CT scans, the thoracic aorta and pulmonary arteries were manually segmented; 395 randomly selected scans with the corresponding ground truth segmentations were used to train a CNN with a 3D U-Net architecture. The remaining 70 scans were used for testing. The trained CNN was embedded within computational geometry processing pipeline which provides aortic metrics of interest for TEVAR planning. The resulting metrics included aortic arch centerline radius of curvature, proximal landing zones (PLZs) maximum diameters, angulation, and tortuosity. These parameters were statistically analyzed to compare standard arches vs. arches with a common origin of the innominate and left carotid artery (CILCA). The trained CNN yielded a mean Dice score of 0.95 and was able to generalize to 9 pathological cases of thoracic aortic aneurysm, providing accurate segmentations. CILCA arches were characterized by significantly greater angulation (p = 0.015) and tortuosity (p = 0.048) in PLZ 3 vs. standard arches. For both arch configurations, comparisons among PLZs revealed statistically significant differences in maximum zone diameters (p < 0.0001), angulation (p < 0.0001), and tortuosity (p < 0.0001). Our tool allows clinicians to obtain objective and repeatable PLZs mapping, and a range of automatically derived complex aortic metrics.

Aortic arch variant with a common origin of the innominate and left carotid artery as a determinant of thoracic aortic disease: a systematic review and meta-analysis

The aim of this study was to investigate whether the 'bovine' arch [i.e. arch variant with a common origin of the innominate and left carotid artery (CILCA)] is associated with an increased risk of thoracic aortic disease (TAD). The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed, EMBASE and Cochrane databases were searched to identify all case series reporting about CILCA arch and TAD between January 2008 and December 2018. A total of 485 studies were screened. The prevalence of CILCA arch was assessed, and data analysis was performed considering the difference in the risk of TAD for presence versus absence of CILCA arch. Eight studies enrolling 11 381 subjects were retrieved for quantitative analysis. The proportion of TAD among CILCA arch patients was higher [41.5% (28.1-56.4)] than the proportion among patients with standard arch configuration 34.0% (20.1-51.4). The odds ratio of developing TAD was 1.4 times higher in subjects with CILCA arch (95% confidence interval 1.068-1.839). The test for an overall effect indicated a significant association between CILCA arch and TAD (P < 0.015). The I2 was 78.1% with a value of P < 0.001 for heterogeneity. The Egger test did not show evidence of publication bias (P = 0.317). In conclusion, our meta-analysis supports the hypothesis of a correlation between the presence of CILCA arch and the onset of TAD. Our results warrant a specific and long-term surveillance for patients with this anatomical variant, and a thorough awareness of its potential clinical implications during image interpretation.

A systematic classification of the left-sided aortic arch variants based on cadaveric studies' prevalence

INTRODUCTION

Typical branching pattern of the left-sided aortic arch consists of the brachiocephalic trunk (BCT), the left common carotid artery (LCCA) and the left subclavian artery (LSA). Variant patterns have been associated with a broad spectrum of pathologies. The meticulous knowledge of potential aortic arch variants is of utmost importance to radiologists, interventional cardiologists, vascular and thoracic surgeons. The current systematic review collects all aortic arch branching patterns and their frequency as published by various cadaveric studies, calculates prevalence taking into account the gender and the different people background, as well. All extracted variant patterns are classified into types and subtypes according to the number of emerging (major and minor) branches (1, 2, 3, 4 and 5) and to the prevalence they appear. In cases of similar prevalence, total cases were taken into consideration; otherwise the variants were classified under the title "other rare variants".

METHODS

A systematic online search of PubMed and Google books databases was performed only in cadaveric studies.

RESULTS

Twenty studies with typical (78% prevalence) and variable (22%) branching patterns were included. Types 3b, 2b, 4b, 1b and 5b had a prevalence of 81%, of 13%, of 5%, 0% and of 0%, respectively. Common variants were the brachiocephalico-carotid trunk (BCCT, 49% prevalence), the aberrant left vertebral artery (LVA, 41%) and the aberrant right subclavian artery (ARSA, 8%). LVA of aortic origin was detected in 32%, the bicarotid trunk (biCT) in 5% and the bi-BCT trunk in 3%. Thyroidea ima artery, a minor branch emerging from the aortic arch was found in 2%. Coexisted variants were detected in 4% (ARSA with a distinct RCCA and LCCA origin), in 3% (BCCT with a LVA of aortic origin), in 2% (ARSA with a biCT and a vertebrosubclavian trunk).

CONCLUSION

No significant gender or ethnic differences exist among the 5 branching types. The proposed classification scheme aims to become a valuable and easy to use tool in the hands of all physicians involved in diagnosis and treatment of aortic arch pathology. It could be also useful in anatomical education, as well.

Thoracic aortic size in Brazilian smokers: measures using low-dose chest computed tomography anatomical and epidemiological assessment

OBJECTIVES

Thoracic aortic aneurysms (TAAs) represent one-third of the hospitalizations for aortic diseases. The prevalence rate depends on the definition of the normal size of the aorta, which is quite variable, depending on the population studied. The aim of this study was to evaluate the characteristics of the thoracic aorta of Brazilian smokers, identifying the normal size of the aorta, presence of anatomical variations, and prevalence of TAA.

MATERIALS AND METHODS

A total of 711 patients underwent radiological evaluation with low-dose computed tomography (CT) from January 2013 to July 2014 with the initial objective of lung nodule tracking. Two examiners evaluated these images, and measurements of maximum and serial diameters were performed manually in true orthogonal planes. Serial diameter measurements were taken every 2 cm in the ascending aorta and 5 cm in the descending segment. We searched for anatomical variations, aortic arch type, and correlations between anatomical characteristics, sex, body mass index, and body surface area (BSA).

RESULTS

The maximum diameters were 33.61 (standard deviation [SD] 3.88), 28.66 (SD 2.89), and 28.36 mm (SD 3.09) for the ascending segment, aortic arch, and descending segment, respectively. A positive correlation was found between male sex, age, and BSA and aorta diameter. The bovine arch was the most common variation of the aortic arch type, and we found one (0.14%) case of TAA.

CONCLUSIONS

This study with low-dose CT allowed the determination of the mean diameters of the ascending aorta, aortic arch, and descending aorta in Brazilian smokers and TAA prevalence.

Computational Fluid Dynamics Modeling of Proximal Landing Zones for Thoracic Endovascular Aortic Repair in the Bovine Arch Variant

BACKGROUND

To assess the endograft displacement forces (DF), which quantify the forces exerted by the pulsatile blood flow on the vessel wall and transmitted on the terminal fixation site of the endograft after its deployment in proximal landing zones (PLZs) of the bovine aortic arch variant.

METHODS

Thirty healthy aortic computed tomographic angiographies of subjects with bovine arch configuration (10 per type of arch, I-III) were selected for the purpose of the study. A 3-dimensional model of the aortic arch lumen was reconstructed. Computational fluid dynamics modeling was then used to compute DF magnitude and orientation (i.e., x, y, and z axes) in PLZs of each case. DF values were normalized to the corresponding aortic wall area to estimate equivalent surface traction (EST).

RESULTS

DF were highest in zone 0, consistently with the greater surface area. DF in zone 3 were much greater than in zone 2 because of a 3-fold greater upward component (z axis) (P < 0.001), being therefore mainly oriented orthogonally to the aortic blood flow and to the vessel longitudinal axis in that zone. EST progressively increased from zone 0 toward more distal PLZs, with EST in zone 3 being much greater than that in zone 2 (P < 0.001). The same pattern was observed after stratification by type of arch.

CONCLUSIONS

The bovine arch is associated with a consistent fluid dynamic pattern, which identifies in zone 3 an unfavorable biomechanical environment for endograft deployment.

Higher Prevalence of Bovine Aortic Arch Configuration in Patients Undergoing Blunt Isthmic Aortic Trauma Repair

BACKGROUND

The prevalence of a bovine aortic arch configuration is higher in patients treated for thoracic aortic aneurysms and type B dissection; its prevalence in aortic isthmic trauma has not been described.

METHODS

A case control study was performed comparing consecutive patients treated at our institution for acute isthmic aortic transection after blunt trauma between 2002 and 2019 and a control group of consecutive sex-matched individuals undergoing imaging for nonaortic disease. Imaging and clinical findings were reviewed. Subjects were divided into bovine and nonbovine groups and prevalence was compared. The length of the aortic segment between the left subclavian artery (LSA) and the next proximal great vessel was measured in the control population and a comparison was performed between bovine and nonbovine aortic arch subjects.

RESULTS

Thirty-three consecutive (30 male) patients were reviewed, 66 individuals (60 male) were included in the control group. A higher incidence of bovine arch in trauma patients was found: 57.6% vs. 34.8% (P = 0.007). The median (range, mm) and mean (SD) distance between the bovine trunk and the LSA were 13 mm (2-27) and 12.4 mm (5.9), respectively, compared with 5 mm (1-27) and 7.8 mm (6.1) between the left common carotid and LSA in nonbovine aortic arches (P < 0.005).

CONCLUSION

A higher incidence of bovine arch in patients reaching out for surgical treatment for traumatic isthmic aortic transection was found in our population. Clinical interpretation of this finding can lead to several alternatives. Confirmation with larger series and data on prevalence of this anatomic variation in nonsurvivors is needed to provide a better understanding of this finding.

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.