An unusual variation of vertebral artery

Anand A. Jamkar^1* and Anjali S. Sabins²

¹Department of Anatomy, S.B.H. Government Medical College, Dhule, Maharashtra, India

²Department of P.G. Studies and Research in Biotechnology & Bioinformatics, Kuvempu University, Shankaraghatta 577451, Karnataka, India.

*Corresponding Author:

Dr. Anand A. Jamkar
Associate Professor, of Anatomy S.B.H. Government Medical College, Dhule (Maharashtra) ‘Chaitanya’, 23, Ashok Nagar, Dhule 424001, Maharashtra, India
Tel: +91 2562 245568
E-mail: anand_jamkar71@yahoo.co.in

Date of Received: February 26^th, 2013

Date of Accepted: October 27^th, 2013

Published Online: June 1^st, 2014

© Int J Anat Var (IJAV). 2014; 7: 32–34.

Keywords

vertebral artery, subclavian artery, common carotid artery

Introduction

Variations are part and parcel of Human Anatomy; and they are being creating interest in surgeons, radiologist, physicians and anatomists.

The vertebral artery normally arises from the posterosuperior aspect of the first part of the subclavian artery. The first part of the vertebral artery passes back and upwards between longus colli and scalenus anterior muscle, behind the common carotid artery and the vertebral vein. The second part ascends through the transverse foramina of all the cervical vertebrae except seventh [1].

Case Report

We noticed an unusual variation in a 70-year-old female embalmed cadaver in the Department of Anatomy during routine dissection of neck. The right vertebral artery exhibited variation in the origin. It originated from the right common carotid artery, then ascended upwards with usual course and entered transverse foramen of sixth cervical vertebra (Figure 1). On the left side, the origin and course of the vertebral artery was as usual. No other variations were found in neck structures and their relations.

Figure 1: Photograph showing the variant right vertebral artery. (BP: brachial plexus; SA: scalenus anterior; PN: phrenic nerve; RCCA: right common carotid artery; RVA: right vertebral artery; RSA: right subclavian artery)

Discussion

A variation in the origin and distribution of vertebral artery can cause alteration in cerebral hemodynamics that may predispose to aneurismal formation with a greater risk of cerebrovascular events [2,3]. Occurrence and awareness of variations in origin of vertebral artery is not only surgically important, but also clinically significant from radiological point of view.

According to Schultz “Evolution will continue as long as variations occur” [4], and variations is a rule in anatomy.

De Garis [5] has reported that the vertebral artery is one of the most constant branches of subclavian artery. Stebbins [6] supported their comments by saying that unusual origin of vertebral artery is relatively rare. Iyer [7], in Indian population has reported that it is a rare presentation. Still large numbers of variations are documented in the origin of vertebral artery. Majority of the variations are in relation to left vertebral artery and its origin from arch of aorta; between left common carotid artery and left subclavian artery. The incidence of such origin from arch of aorta is 1.0 to 5.8% in different studies [8,9].

Table 1 shows the different variations in the origin of vertebral arteries.

Table 1: Table shows the different variations in the origin of vertebral arteries.

Nathan et al. [20] reported a left vertebral artery of aortic origin associated with the retro-oesophageal right subclavian artery, yet with normal origin of right vertebral artery. According to Hollinshead [21], the vertebral artery may arise lateral to or with the thyrocervical trunk instead of medial to it. He had quoted a case in which vertebral artery arose by two stems – one from brachiocephalic trunk & other from left subclavian artery. Nogueira et al. [22] had reported a dual origin of vertebral artery mimicking dissection on angiographic study.

According to Palmer [23] vertebral artery originates from common carotid artery only in 0.18% of cases, and according to Ligege [8] it is 0.28%. This unusual origin is often associated with the retro-oesophageal right subclavian artery. Similar observation was made by Vicko [24]. They have reported an unusual origin of both vertebral arteries – right one from right common carotid artery and left one from common trunk of it, and the left subclavian artery at the aortic arch, with the retro-oesophageal right subclavian artery. The present case exhibits unusual origin of right vertebral artery without any associated variations in other structures.

The vertebral artery normally develops as follows: The vessel appears as a branch of dorsal division of the seventh cervical intersegmental artery. The post-costal anastomosis between the level of first and sixth cervical segments becomes enlarged to form the portion of the vertebral artery lying within the costo-transverse foramina of the cervical vertebrae. [25]. The possible embryological explanation for the present variation can be as follows: dorsal division of the seventh cervical intersegmental artery may not have formed, and may have been replaced by a branch from the right third aortic arch artery which forms common carotid artery.

The variation can have serious implication in neck surgeries. This anatomical characteristic of the variation needs attention during anterior cervical spine surgery, thyroid surgery or other interventions. During thyroidectomy, the inferior thyroid artery is usually ligated. It may be near to such unusual vertebral artery. Hence meticulous care may be needed to avoid an inadvertent injury to the vertebral artery during thyroidectomy. During thyroid aspiration, the needle occasionally penetrates the posterior surface of the thyroid gland and it reaches the vertebral body. If the unusual vertebral artery is near to the thyroid gland, then there is a possibility to puncture it during thyroid aspiration. Therefore, knowledge of this variation of right vertebral artery may be helpful to avoid injury of it when performing these procedures. It is of great importance that the neuro-physicians be aware of such a possibility. Also for angiographic procedures such variation should be kept in mind.

References

1. Standring S, ed. Gray’s Anatomy. 39th Ed., Elsevier Churchill Livingstone. 2005; 549.
2. Bernardi L, Detori P. Angiographic study of a rare anomalous origin of the vertebral artery. Neuroradiology. 1975; 9: 43–47.
3. Satti SR, Cerniglia CA, Koenigsberg RA. Cervical vertebral artery variations: an anatomic study. AJNR Am J Neuroradiol. 2007; 28: 976–980.
4. Schultz AH. Variations in man and their evolutionary significance. Am Nat. 1926; 60; 297–323.
5. De Garis CF. Patterns of branching of subclavian artery in White and Negro stocks. Am J Phys Anthrop. 1924; 7: 95–107.
6. Stebbins TA. A report of a case of an anomalous right subclavian artery in man with a rare arrangement of the associated arteries. Anat Rec. 1949; 103: 139–149.
7. Iyer AA. Some anomalies of origin of the vertebral artery. J Anat. 1927; 62: 121–122.
8. Ligege P, Scholtz L. Rare variation in the origin of the right vertebral artery. South Afr J Radiol. 2004; 8: 34–35.
9. Vorster W, Du Plooy PT, Meiring JH. Abnormal origin of internal thoracic and vertebral arteries. Clin Anat. 1998; 11: 33–37.
10. Himabindu A, Rao NB. A study on variant origins of vertebral artery. Int J Basic Appl Med Sci. 2012; 2: 34–37.
11. Jayanthi V, Prakash, Devi MN, Geethanjali BS, Rajini T. Anomalous origin of the left vertebral artery from the arch of the aorta: review of the literature and a case report. Folia Morphol (Warsz). 2010; 69: 258–260.
12. Nasir S, Hussain M, Khan SA, Mansoor MA, Sharif S. Anomalous origin of right vertebral artery from right external carotid artery. J Coll Physicians Surg Pak. 2010; 20: 208–210.
13. Kubikowa E, Osvaldova M, Mizerakova P, El Falougy H, Benuska J. A variable origin of the vertebral artery. Bratisl Lek Listy. 2008; 109: 28–30.
14. Kim YD1, Yeo HT, Cho YD. Anomalous variations of the origin and course of vertebral arteries in patients with retroesophageal right subclavian artery. J Korean Neurosurg Soc. 2009; 45: 297–299.
15. Patasi B, Yeung A, Goodwin S, Jalani A. Anatomical variation of the origin of the left vertebral artery. Int J Anat Var (IJAV). 2009; 2: 83–85.
16. Imre N, Yalcin B, Ozan H. Unusual origin of the left vertebral artery. Int J Anat Var (IJAV). 2010; 3: 80–82.
17. Panicker HK, Tarnekar A, Dhawane V, Ghosh SK. Anomalous origin of left vertebral artery: embryological basis and applied aspects. J Anat Soc India. 2002; 51: 234–235.
18. Matula C, Trattnig S, Tschabitscher M, Day JD, Koos WT. The course of the prevertebral segment of the prevertebral artery: anatomy and clinical significance. Surg Neurol. 1997; 48: 125–131.
19. Park JK, Kim SH, Kim BS, Choi G. Two cases of aberrant right subclavian artery and right vertebral artery that originated from the right common carotid artery. Korean J Radiol. 2008; 9(Suppl): S39-S42.
20. Nathan H, Siedel MR. The association of the retroesophageal right subclavian artery, a right sided terminating thoracic duct, and a left vertebral artery of aortic origin : Anatomical and clinical considerations . Acta Anat (Basel). 1983; 117: 362–373.
21. Hollinshead WH. Anatomy for Surgeons. 3rd Ed., Vol. 1, Philadelphia, Harper and Row. 1971; 454.
22. Nogueira TE, Chambers AA, Brueggemeyer MT, Miller TJ. Dual origin of the vertebral artery mimicking dissection. AJNR Am J Neuroradiol. 1997; 18: 382–384.
23. Palmer FJ. Origin of the right vertebral artery from right common carotid artery. Angiographic demonstration of three cases. Brit J Radiol. 1977; 50: 185–187.
24. Gluncic V, Ivkic G, Marin D, Percac S. Anomalous origin of both vertebral arteries. Clin Anat. 1999; 12: 281–284.
25. Hamilton WJ, Mossman HW. Human Embryology. Prenatal development of form and Function. London, The Williams and Wilkins Co. 1972; 270.

Anand A. Jamkar^1* and Anjali S. Sabins²

¹Department of Anatomy, S.B.H. Government Medical College, Dhule, Maharashtra, India

²Department of P.G. Studies and Research in Biotechnology & Bioinformatics, Kuvempu University, Shankaraghatta 577451, Karnataka, India.

*Corresponding Author:

Dr. Anand A. Jamkar
Associate Professor, of Anatomy S.B.H. Government Medical College, Dhule (Maharashtra) ‘Chaitanya’, 23, Ashok Nagar, Dhule 424001, Maharashtra, India
Tel: +91 2562 245568
E-mail: anand_jamkar71@yahoo.co.in

Date of Received: February 26^th, 2013

Date of Accepted: October 27^th, 2013

Published Online: June 1^st, 2014

© Int J Anat Var (IJAV). 2014; 7: 32–34.

Abstract

Vertebral artery is the first branch of subclavian artery which joins other sided vertebral artery to form basilar artery and becomes important source of blood supply to the brain.
The complex embryological development of vascular system often results in myriad of clinically relevant variations. Variation in the origin of right vertebral artery was found in 70-year-old female embalmed cadaver during routine dissection of neck in the department of anatomy. It was originating from right common carotid artery and its further course was as usual. Origin and course of left vertebral artery showed no variation.
Such type of variation is encountered very rarely. Awareness of such variations in origin is surgically important and clinically significant during diagnostic and interventional angiographic procedures.

Keywords

vertebral artery, subclavian artery, common carotid artery

Introduction

Variations are part and parcel of Human Anatomy; and they are being creating interest in surgeons, radiologist, physicians and anatomists.

The vertebral artery normally arises from the posterosuperior aspect of the first part of the subclavian artery. The first part of the vertebral artery passes back and upwards between longus colli and scalenus anterior muscle, behind the common carotid artery and the vertebral vein. The second part ascends through the transverse foramina of all the cervical vertebrae except seventh [1].

Case Report

We noticed an unusual variation in a 70-year-old female embalmed cadaver in the Department of Anatomy during routine dissection of neck. The right vertebral artery exhibited variation in the origin. It originated from the right common carotid artery, then ascended upwards with usual course and entered transverse foramen of sixth cervical vertebra (Figure 1). On the left side, the origin and course of the vertebral artery was as usual. No other variations were found in neck structures and their relations.

Figure 1: Photograph showing the variant right vertebral artery. (BP: brachial plexus; SA: scalenus anterior; PN: phrenic nerve; RCCA: right common carotid artery; RVA: right vertebral artery; RSA: right subclavian artery)

Discussion

A variation in the origin and distribution of vertebral artery can cause alteration in cerebral hemodynamics that may predispose to aneurismal formation with a greater risk of cerebrovascular events [2,3]. Occurrence and awareness of variations in origin of vertebral artery is not only surgically important, but also clinically significant from radiological point of view.

According to Schultz “Evolution will continue as long as variations occur” [4], and variations is a rule in anatomy.

De Garis [5] has reported that the vertebral artery is one of the most constant branches of subclavian artery. Stebbins [6] supported their comments by saying that unusual origin of vertebral artery is relatively rare. Iyer [7], in Indian population has reported that it is a rare presentation. Still large numbers of variations are documented in the origin of vertebral artery. Majority of the variations are in relation to left vertebral artery and its origin from arch of aorta; between left common carotid artery and left subclavian artery. The incidence of such origin from arch of aorta is 1.0 to 5.8% in different studies [8,9].

Table 1 shows the different variations in the origin of vertebral arteries.

Table 1: Table shows the different variations in the origin of vertebral arteries.

Nathan et al. [20] reported a left vertebral artery of aortic origin associated with the retro-oesophageal right subclavian artery, yet with normal origin of right vertebral artery. According to Hollinshead [21], the vertebral artery may arise lateral to or with the thyrocervical trunk instead of medial to it. He had quoted a case in which vertebral artery arose by two stems – one from brachiocephalic trunk & other from left subclavian artery. Nogueira et al. [22] had reported a dual origin of vertebral artery mimicking dissection on angiographic study.

According to Palmer [23] vertebral artery originates from common carotid artery only in 0.18% of cases, and according to Ligege [8] it is 0.28%. This unusual origin is often associated with the retro-oesophageal right subclavian artery. Similar observation was made by Vicko [24]. They have reported an unusual origin of both vertebral arteries – right one from right common carotid artery and left one from common trunk of it, and the left subclavian artery at the aortic arch, with the retro-oesophageal right subclavian artery. The present case exhibits unusual origin of right vertebral artery without any associated variations in other structures.

The vertebral artery normally develops as follows: The vessel appears as a branch of dorsal division of the seventh cervical intersegmental artery. The post-costal anastomosis between the level of first and sixth cervical segments becomes enlarged to form the portion of the vertebral artery lying within the costo-transverse foramina of the cervical vertebrae. [25]. The possible embryological explanation for the present variation can be as follows: dorsal division of the seventh cervical intersegmental artery may not have formed, and may have been replaced by a branch from the right third aortic arch artery which forms common carotid artery.

The variation can have serious implication in neck surgeries. This anatomical characteristic of the variation needs attention during anterior cervical spine surgery, thyroid surgery or other interventions. During thyroidectomy, the inferior thyroid artery is usually ligated. It may be near to such unusual vertebral artery. Hence meticulous care may be needed to avoid an inadvertent injury to the vertebral artery during thyroidectomy. During thyroid aspiration, the needle occasionally penetrates the posterior surface of the thyroid gland and it reaches the vertebral body. If the unusual vertebral artery is near to the thyroid gland, then there is a possibility to puncture it during thyroid aspiration. Therefore, knowledge of this variation of right vertebral artery may be helpful to avoid injury of it when performing these procedures. It is of great importance that the neuro-physicians be aware of such a possibility. Also for angiographic procedures such variation should be kept in mind.

References

1. Standring S, ed. Gray’s Anatomy. 39th Ed., Elsevier Churchill Livingstone. 2005; 549.
2. Bernardi L, Detori P. Angiographic study of a rare anomalous origin of the vertebral artery. Neuroradiology. 1975; 9: 43–47.
3. Satti SR, Cerniglia CA, Koenigsberg RA. Cervical vertebral artery variations: an anatomic study. AJNR Am J Neuroradiol. 2007; 28: 976–980.
4. Schultz AH. Variations in man and their evolutionary significance. Am Nat. 1926; 60; 297–323.
5. De Garis CF. Patterns of branching of subclavian artery in White and Negro stocks. Am J Phys Anthrop. 1924; 7: 95–107.
6. Stebbins TA. A report of a case of an anomalous right subclavian artery in man with a rare arrangement of the associated arteries. Anat Rec. 1949; 103: 139–149.
7. Iyer AA. Some anomalies of origin of the vertebral artery. J Anat. 1927; 62: 121–122.
8. Ligege P, Scholtz L. Rare variation in the origin of the right vertebral artery. South Afr J Radiol. 2004; 8: 34–35.
9. Vorster W, Du Plooy PT, Meiring JH. Abnormal origin of internal thoracic and vertebral arteries. Clin Anat. 1998; 11: 33–37.
10. Himabindu A, Rao NB. A study on variant origins of vertebral artery. Int J Basic Appl Med Sci. 2012; 2: 34–37.
11. Jayanthi V, Prakash, Devi MN, Geethanjali BS, Rajini T. Anomalous origin of the left vertebral artery from the arch of the aorta: review of the literature and a case report. Folia Morphol (Warsz). 2010; 69: 258–260.
12. Nasir S, Hussain M, Khan SA, Mansoor MA, Sharif S. Anomalous origin of right vertebral artery from right external carotid artery. J Coll Physicians Surg Pak. 2010; 20: 208–210.
13. Kubikowa E, Osvaldova M, Mizerakova P, El Falougy H, Benuska J. A variable origin of the vertebral artery. Bratisl Lek Listy. 2008; 109: 28–30.
14. Kim YD1, Yeo HT, Cho YD. Anomalous variations of the origin and course of vertebral arteries in patients with retroesophageal right subclavian artery. J Korean Neurosurg Soc. 2009; 45: 297–299.
15. Patasi B, Yeung A, Goodwin S, Jalani A. Anatomical variation of the origin of the left vertebral artery. Int J Anat Var (IJAV). 2009; 2: 83–85.
16. Imre N, Yalcin B, Ozan H. Unusual origin of the left vertebral artery. Int J Anat Var (IJAV). 2010; 3: 80–82.
17. Panicker HK, Tarnekar A, Dhawane V, Ghosh SK. Anomalous origin of left vertebral artery: embryological basis and applied aspects. J Anat Soc India. 2002; 51: 234–235.
18. Matula C, Trattnig S, Tschabitscher M, Day JD, Koos WT. The course of the prevertebral segment of the prevertebral artery: anatomy and clinical significance. Surg Neurol. 1997; 48: 125–131.
19. Park JK, Kim SH, Kim BS, Choi G. Two cases of aberrant right subclavian artery and right vertebral artery that originated from the right common carotid artery. Korean J Radiol. 2008; 9(Suppl): S39-S42.
20. Nathan H, Siedel MR. The association of the retroesophageal right subclavian artery, a right sided terminating thoracic duct, and a left vertebral artery of aortic origin : Anatomical and clinical considerations . Acta Anat (Basel). 1983; 117: 362–373.
21. Hollinshead WH. Anatomy for Surgeons. 3rd Ed., Vol. 1, Philadelphia, Harper and Row. 1971; 454.
22. Nogueira TE, Chambers AA, Brueggemeyer MT, Miller TJ. Dual origin of the vertebral artery mimicking dissection. AJNR Am J Neuroradiol. 1997; 18: 382–384.
23. Palmer FJ. Origin of the right vertebral artery from right common carotid artery. Angiographic demonstration of three cases. Brit J Radiol. 1977; 50: 185–187.
24. Gluncic V, Ivkic G, Marin D, Percac S. Anomalous origin of both vertebral arteries. Clin Anat. 1999; 12: 281–284.
25. Hamilton WJ, Mossman HW. Human Embryology. Prenatal development of form and Function. London, The Williams and Wilkins Co. 1972; 270.