Abstract
Objective
A right-sided aortic arch is a rare vascular anomaly, and neuroendovascular therapy through the right-sided aortic arch is extremely rare. Herein, we report the case of a patient with a right-sided aortic arch who performed a mechanical thrombectomy for medium-vessel occlusion.
Case Presentation
An 84-year-old woman could not respond to her family during a conversation at 8:50 am. She was brought to our hospital at 10:30 am on the same day. A diffusion-weighted image of head magnetic resonance imaging revealed a high-intensity area in the left temporal lobe. Head magnetic resonance angiography revealed a loss of the inferior trunk of the left middle cerebral artery. A mechanical thrombectomy was performed. The guiding catheter ascended on the right side from the midline, and the patient was considered to have a right-sided aortic arch. Selecting the left common carotid artery was difficult due to its unusual origin from the ascending aorta. Internal carotid angiography revealed left temporo-occipital artery occlusion. Mechanical thrombectomy was performed using Solitaire X 3× 20 mm (Covidien, Irvine, CA, USA), and recanalization was achieved. Contrast-enhanced chest and abdominal computed tomography revealed a right-sided aortic arch with an aberrant left subclavian artery. She was transferred to a recovery hospital with a modified Rankin Scale score of 1.
Conclusion
Understanding the branching patterns and classifications of the right-sided aortic arch is necessary for physicians performing mechanical thrombectomy.
Keywords: mechanical thrombectomy, medium vessel occlusion, right-sided aortic arch
Introduction
A right-sided aortic arch is a rare vascular anomaly that occurs during embryologic development.1) A left-sided aortic arch is formed by the left fourth aortic arch and left dorsal aorta.2–4) A right-sided aortic arch is formed by complete occlusion between the left fourth aortic arch and left dorsal aorta, leaving the right fourth aortic arch and right dorsal aorta.5,6) The incidence of a right-sided aortic arch is 0.04%–0.14% worldwide.5,6) A right-sided aortic arch is a rare vascular anomaly, and neuroendovascular therapy through the right-sided aortic arch is extremely rare. Furthermore, with the miniaturization of MT devices, favorable outcomes of endovascular therapy for medium-vessel occlusion (MeVO) have been reported in recent years.7,8) Herein, we report the case of a patient with a right-sided aortic arch who performed a mechanical thrombectomy for MeVO.
Case Presentation
The patient was an 84-year-old woman who was last found to be healthy on the day before admission at 18:00 pm. Her family spoke to her at 8:50 am on the day of admission, but she was unable to respond. She was brought to our hospital at 10:30 am on the same day. She walked by herself but was accompanied by her family. On arrival, her Glasgow Coma Scale score was 12 (E4, V3, M5), with sensory aphasia and no apparent paresis. Her National Institutes of Health Stroke Scale (NIHSS) score was 8. The blood pressure and pulse rate were 145/87 mmHg and 80 beats/min, respectively. Her electrocardiogram revealed atrial fibrillation. A diffusion-weighted image (DWI) of her head magnetic resonance imaging (MRI) revealed a high-intensity area in the left temporal lobe, and the diffusion-weighted image-Alberta Stroke Program Early Computed Tomography Score was 9 (Fig. 1A and 1B). Head magnetic resonance angiography (MRA) revealed a loss of the inferior trunk of the left middle cerebral artery (Fig. 1C). Mechanical thrombectomy was performed without the administration of recombinant tissue-type plasminogen activator (rt-PA) at the time of onset was unclear. An 8-Fr long sheath (Medikit Co., Ltd., Tokyo, Japan) was inserted into the right femoral artery. Radifocus 35-Guide-Wire (MicroVention Terumo, Tustin, CA, USA) and a 6-Fr JB-2 catheter (Medikit Co., Ltd.) were used to guide an 8-Fr Emboguard balloon guide catheter (Johnson & Johnson, New Brunswick, NJ, USA). The catheter system ascended on the right side from the midline, and the patient was considered to have a right-sided aortic arch (Fig. 2A). It was difficult to select the left common carotid artery (CCA) because the vascular structure was unknown. The left CCA was found to branch off from a site close to the heart in the ascending aorta (Fig. 2B). The left internal carotid artery (ICA) was selected using Radifocus 35-Guide-Wire, and the JB-2 catheter was guided along the left CCA. After the JB-2 catheter was overtaken by the Emboguard balloon guide catheter and turned upward, the JB-2 catheter was guided again to the left ICA. Finally, the Emboguard balloon guide catheter was guided into the left ICA (Fig. 2C and 2D). The time from a puncture to the induction of the Emboguard balloon guide catheter into the left ICA was 12 minutes.
Fig. 1. (A, B) Diffusion-weighted image of head magnetic resonance imaging on arrival revealed a high-intensity area in the left temporal lobe. (C) Head magnetic resonance angiography revealed a loss of the inferior trunk of the left middle cerebral artery.
Fig. 2. Mechanical thrombectomy. (A) Radifocus 35-Guide-Wire and 6-Fr JB-2 catheter were used to guide an 8-Fr Emboguard balloon guide catheter. The catheter system ascended on the right side from the midline, and the patient was considered to have a right-sided aortic arch. (B) The left CCA was found to branch from a site close to the heart in the ascending aorta. (C) A balloon guide catheter was guided into the left ICA (frontal view). (D) A balloon guide catheter was guided into the left ICA (lateral view). (E) Internal carotid angiography revealed left temporo-occipital artery occlusion (frontal view). (F) Internal carotid angiography revealed left temporo-occipital artery occlusion (lateral view). (G) A microcatheter was guided to the distal side of the thrombus, and microcatheter angiography was performed. (H) Mechanical thrombectomy was performed using Solitaire X 3 × 20 mm. (I) Recanalization was achieved (frontal view). (J) Recanalization was achieved (lateral view). 6-Fr JB-2 catheter, Medikit Co., Ltd., Tokyo, Japan; 8-Fr Emboguard balloon guide catheter, Johnson & Johnson, New Brunswick, NJ, USA; CCA, common carotid artery; ICA, internal carotid artery; Radifocus 35-Guide-Wire, MicroVention Terumo, Tustin, CA, USA.
Internal carotid angiography revealed left temporo-occipital artery occlusion (Fig. 2E and 2F). A Cereglide 71 intermediate catheter (Johnson & Johnson) was guided to the cavernous portion of the left ICA. A Trevo track 21 (Stryker, Kalamazoo, MI, USA) microcatheter was guided to the distal part of the thrombus using a Synchro standard straight micro-guidewire (Stryker), and microcatheter angiography was performed (Fig. 2G). Mechanical thrombectomy was performed using Solitaire X 3 × 20 mm (Covidien, Irvine, CA, USA) (Fig. 2H), and recanalization was achieved (Fig. 2I and 2J). The puncture-to-reperfusion time was 32 minutes. DWI of her head MRI revealed a slight cerebral infarction in the left temporal lobe (Fig. 3A), and her head MRA revealed no re-occlusion of the temporo-occipital artery (Fig. 3B). Contrast-enhanced chest and abdominal computed tomography (CT) revealed a right-sided aortic arch with an aberrant left subclavian artery (Fig. 4A), and chest X-ray consistently revealed a right-sided aortic arch (Fig. 4B). The patient gradually improved (with an NIHSS score of 1), and she was transferred to a recovery hospital with a modified Rankin Scale score of 1.
Fig. 3. (A) A diffusion-weighted image of head magnetic resonance imaging revealed a slight cerebral infarction in the left temporal lobe. (B) Head magnetic resonance angiography revealed no re-occlusion of the temporo-occipital artery.
Fig. 4. (A) Contrast-enhanced chest and abdominal computed tomography revealed a right-sided aortic arch with an aberrant left subclavian artery. (B) Chest X-ray revealed a right-sided aortic arch. Black arrow, left CCA; black arrowhead, right CCA; white arrow, right subclavian artery; white arrowhead, left subclavian artery; dotted arrow, Kommerell’s diverticulum. CCA, common carotid artery.
Discussion
The aortic arch is formed when 6 pairs of branchial arteries appear on each side, and some of them immediately disappear during the first 4 weeks of the embryonic period. In general, the first, second, and fifth aortic arches tend to disappear, and the left fourth aortic arch forms part of the definitive aortic arch.9) A right-sided aortic arch is formed by complete occlusion between the left fourth aortic arch and left dorsal aorta, leaving the right fourth aortic arch and right dorsal aorta.5,6)
The right-sided aortic arch is broadly classified into the following: (A) aortic arch with the post-esophageal aorta and (B) aortic arch without the post-esophageal aorta. Based on the running of the left subclavian artery, (B) is further classified into the following: (B-1) mirror-image branching, (B-2) an aberrant left subclavian artery, and (B-3) left subclavian artery isolation5,10–12) (Fig. 5). Congenital heart disease has been reported to complicate 75%–86% cases of (B-1) and (B-3), and 5%–10% cases of (B-2). Patients with (B-2) may have a Kommerell’s diverticulum at the bifurcation of the left subclavian artery. The rate of rupture of Kommerell’s diverticulum leading to mortality in patients with this condition has been reported to be 19%.13) Our case was classified as (B-2) because the left CCA, right CCA, right subclavian artery, and left subclavian artery arose from the side closer to the heart.
Fig. 5. Knight and Edwards classification.4,6–8) (A) A right-sided aortic arch with a retroesophageal aortic segment. (B-1, B-2, B-3) A right-sided aortic arch without a retroesophageal aortic segment (B-1, mirror-image branching; B-2, aberrant left subclavian artery; B-3, isolation of the left subclavian artery). Source: Shiraishi et al.12) Permission was obtained to cite the figure from Nosotchu No Geka. LCC, left common carotid artery; LS, left subclavian artery; RCC, right common carotid artery; RS, right subclavian artery.
To the best of our knowledge, there exist previously reported 5 cases of a right-sided aortic arch for which endovascular therapy was performed (Table 1).1,9,12,14,15) In 4 of these cases, carotid artery stenting was performed,1,12,14,15) whereas coiling was performed in the remaining 1 case.9) To the best of our knowledge, this is the first case in which mechanical thrombectomy was performed. The difficulty of the approach depends on the positioning, distance, and angle of bifurcation of the target vessel from the aortic arch apex.12) For cases in which the approach is considered difficult, the choice of approach route and appropriate devices for use should be considered preoperatively, if possible. Ohtani et al.1) previously attempted to guide the inner catheter into the left CCA via the trans-femoral approach (TFA); however, they failed because the inner catheter fell into the ascending aorta. Subsequently, the procedure was performed via the trans-brachial approach (TBA). A 6-Fr guiding sheath was finally guided into the left CCA using a Radifocus half-stiff type 35-Guide-Wire (MicroVention Terumo). They reported that the inner catheter passed through 2 steep turns at the top of the aorta and the low origin of the left CCA via TFA. The advantage of TBA, in this case, is that the catheter passes only through 1 steep turn at the low origin of the left CCA arising from the ascending aorta. They speculated that this is the reason why the inner catheter fell into the ascending aorta when they attempted to advance the catheter to the left CCA. In the present case, the left CCA furthest from the apex of the aortic arch was selected. Despite the potential difficulty in inducing a guiding catheter, it could be induced. If the approach was considered difficult, the use of stiffer guidewires or NeuroEBU (Gadelius Medical, Tokyo, Japan), a Simmonds-type guiding catheter, or a change in the puncture site should be considered. In 4 of the 5 previously reported cases, the right-sided aortic arch was detected preoperatively. For cases in which the approach was considered difficult, a suitable puncture site was selected. In our case, mechanical thrombectomy was required. Usually, when mechanical thrombectomy is performed, there is insufficient time for a preoperative review. Therefore, it is considered necessary for physicians performing mechanical thrombectomy to understand the branching patterns and classifications of the right-sided aortic arch. In our hospital, preoperative routine chest X-rays and chest and abdominal CT for rt-PA, as well as mechanical thrombectomy, are performed for patients who are routinely brought to the emergency room. However, the patient in the current case was not taken to the emergency room but was seen as an outpatient. Therefore, chest X-ray and chest and abdominal CT (which should have been performed routinely) were not performed, and mechanical thrombectomy was performed. Therefore, the right-sided aortic arch was detected for the first time intraoperatively during mechanical thrombectomy. If a right-sided aortic arch is detected on a preoperative chest X-ray or a chest and abdominal CT, chest and abdominal contrast-enhanced CT can be performed to examine the vascular branches of the head and neck. In 3 of the 5 previously reported cases, the right-sided aortic arch was detected incidentally during preoperative neck CT angiography (CTA) or cerebral angiography. In one case, it was detected during coil embolization, whereas in another case, it had already been detected on chest X-ray and chest CT at the time of previous cerebral infarction. In general hospitals, chest X-rays may be performed upon admission. Diagnosing a right-sided aortic arch based on a chest X-ray alone could be difficult. However, when examining the chest X-ray of the current patient retrospectively, we could determine the presence of the right-sided aortic arch. Therefore, it is possible to suspect the right-sided aortic arch by carefully examining the chest X-ray preoperatively. In addition, chest CT is not routinely performed before thrombectomy at all facilities. Furthermore, none of the facilities routinely perform CTA from the neck to the chest before thrombectomy. Therefore, the right-sided aortic arch may be detected during mechanical thrombectomy for the first time, as observed in our case. It was also considered that an aortogram should be performed if the branching of the vessel remains unknown intraoperatively. In our case, as we fortunately detected the location of the left CCA, we did not perform an aortogram. However, if the branching of the vessels of the aortic arch remains unclear because of insufficient time for mechanical thrombectomy or multiple classifications of the right-sided aortic arch (as shown above), an aortogram should be performed immediately. Thus, changing the device or puncture site should be considered depending on the location or angle of branching of the vessel. Several reports of endovascular therapy, including mechanical thrombectomy via the trans-radial approach (TRA), have been published recently.16,17) In a large-scale study examining the puncture region in patients with acute coronary syndrome in the cardiovascular field, the incidence of puncture-site complications was significantly lower in patients treated via TRA than TFA, indicating that it is safer than TFA.16) In a study of mechanical thrombectomy performed via TRA or TFA, the procedure took longer time for TFA than for TRA in patients aged >65 years with a bovine or type II/III aortic arch and tortuous blood vessels. Therefore, the advantages of TRA can be more easily exploited under these conditions than those of TFA.17) The patient in our case was successfully treated via TFA; however, in some cases, mechanical thrombectomy may be performed via TRA. In such cases, it is necessary to consider the approach route before performing mechanical thrombectomy, although there is insufficient time for preoperative assessment.
Table 1. Cases of right-sided aortic arch for which endovascular therapy was performed. In 4 of the 5 previously reported cases, the procedure performed was CAS, whereas in the other case, the procedure performed was coiling. To the best of our knowledge, this is the first case in which a mechanical thrombectomy was performed.
| Case | Age/sex | Knight & Edwards classification |
Location & lesion | Treatment | Approach |
|---|---|---|---|---|---|
| Sakamoto et al.14) | 72/M | B-2 | Left-ICA stenosis | CAS | Right transfemoral |
| Ichinose et al.9) | 60/M | B-2 | Left-MCA aneurysm | Coiling | Right transfemoral |
| Ohtani et al.1) | 69/M | B-2 | Left-ICA stenosis | CAS | Right transbrachial |
| Kato et al.15) | 80/M | B-2 | Left-ICA stenosis | CAS | Right transbrachial |
| Shiraishi et al.12) | 66/M | B-1 | Right-ICA stenosis | CAS | Right transfemoral |
| Kimura et al. | 84/F | B-2 | Left-MCA occlusion | Mechanical thrombectomy |
Right transfemoral |
CAS, carotid artery stenting; ICA, internal carotid artery; MCA, middle cerebral artery
Kommerell’s diverticulum is a diverticulum formed at the bifurcation of the left subclavian artery of the right-sided aortic arch with a residual peripheral portion of the left-sided aortic arch.9) The fatality rate of Kommerell’s diverticulum rupture is high, occurring in 19% of patients with Kommerell’s diverticulum. In the current case, contact with Kommerell’s diverticulum was possible before the left CCA was selected. Therefore, there was a risk of rupture due to catheter manipulation. Careful catheterization was considered necessary during guiding catheter induction in patients with a right-sided aortic arch.
Conclusion
Herein, we report the case of a patient with a right-sided aortic arch who performed a mechanical thrombectomy for MeVO. The right-sided aortic arch has a different branching pattern. Therefore, if possible, a preoperative review of the approach route and appropriate devices for use is desirable. It is considered necessary for physicians performing mechanical thrombectomy to understand the branching patterns and classifications of the right-sided aortic arch.
Acknowledgments
We wish to thank Dr. Hiroshi Imagawa for his advice on experimental design.
Disclosure Statement
The authors declare that there are no conflicts of interest related to this work.
References
- 1).Ohtani T, Yamazaki T, Ohtaki H, et al. Carotid artery stenting in right-sided aortic arch: a case report. NMC Case Rep J 2016; 3: 9–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2).Congdon ED. Transformation of the aortic-arch system during the development of the human embryo. Contrib Embryol Carnegie Inst Wash 1922; Publ 277, 14: 47–110. [Google Scholar]
- 3).Barry A. The aortic arch derivatives in human adult. Anat Rec 1951; 111: 221–238. [DOI] [PubMed] [Google Scholar]
- 4).Nonoyama A, Miyamoto I, Takimoto R, et al. Malformations of aortic arch system and unusually located ductus arteriosus. J Kansai Med Univ 1966; 18: 79–85. (in Japanese) [Google Scholar]
- 5).Hastreiter AR, D’Cruz IA, Cantez T, et al. Right-sided aorta. I. Occurrence of right aortic arch in various types of congenital heart disease. II. Right aortic arch, right descending aorta, and associated anomalies. Heart 1966; 28: 722–739. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6).Ito K, Kogure K, Hayashi S, et al. Analytical evaluation of compression and displacement of the esophagus and trachea due to right aortic arch with MR imaging. Nihon Igaku Hoshasen Gakkai Zasshi 1996; 56: 89–93. (in Japanese) [PubMed] [Google Scholar]
- 7).Rikhtegar R, Mosimann PJ, Weber R, et al. Effectiveness of very low profile thrombectomy device in primary distal medium-vessel occlusion, as rescue therapy after incomplete proximal recanalization or following iatrogenic thromboembolic events. J Neurointerv Surg 2021; 13: 1067–1072. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8).Sweid A, Head J, Tjoumakaris S, et al. Mechanical thrombectomy in distal vessels: revascularization rates, complications, and functional outcome. World Neurosurg 2019; 130: e1098–e1104. [DOI] [PubMed] [Google Scholar]
- 9).Ichinose N, Kiura Y, Sakamoto S, et al. A case of ruptured cerebral aneurysm with a right-sided aortic arch treated by coil embolization. J Neuroendovasc Ther 2013; 7: 317–322. [Google Scholar]
- 10).Knight L, Edwards JE. Right aortic arch. Types and associated cardiac anomalies. Circulation 1974; 50: 1047–1051. [DOI] [PubMed] [Google Scholar]
- 11).Stewart JR, Kindcaid OW, Edwards JE. An atlas of vascular rings and related malformations of the aortic arch system. 1964th ed. Thomas. Springfield, 1964, 8–13, 124–129. [Google Scholar]
- 12).Shiraishi Y, Kimura H, Chatani M, et al. Case of carotid artery stenting with right aortic arch. Nosotchu No Geka 2023; 51: 28–33. (in Japanese) [Google Scholar]
- 13).Austin EH, Wolfe WG. Aneurysm of aberrant subclavian artery with a review of the literature. J Vasc Surg 1985; 2: 571–577. [DOI] [PubMed] [Google Scholar]
- 14).Sakamoto S, Shibukawa M, Tani I, et al. Carotid artery stenting in a patient with right-sided aortic arch with an aberrant left subclavian artery. Acta Neurochir (Wien) 2011; 153: 2169–2173. [DOI] [PubMed] [Google Scholar]
- 15).Kato T, Aki T, Imai N, et al. Carotid artery stenting via the right brachial artery with right aortic arch. No Kekkannai Chiryo 2019; 4: 77–82. (in Japanese) [Google Scholar]
- 16).Jolly SS, Yusuf S, Cairns J, et al. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet 2011; 377: 1409–1420. [DOI] [PubMed] [Google Scholar]
- 17).Snelling BM, Sur S, Shah SS, et al. Unfavorable vascular anatomy is associated with increased revascularization time and worse outcome in anterior circulation thrombectomy. World Neurosurg 2018; 120: e976–e983. [DOI] [PubMed] [Google Scholar]