International Journal of Anatomical Sciences 2012, 3(1): 01-03

Research Article

Abnormal Origin of Vertebral Artery

Anitha, V.

Department of Anatomy, Kanyakumari Government Medical College, Asaripallam, Kanyakumari 629 201, Tamil Nadu, India.

Key words : vertebral artery, arch of aorta, artery

 Abstract: Abnormal origin of vertebral artery (left) from arch of aorta was noticed during dissection of fifty specimens and the same is presented for its  rarity and clinical significance.

 The   vertebral   artery   takes   origin from the first part of subclavian artery and its branches supply the spinal cord, medulla oblongata and cerebellum.

It has become important to know the exact  origin  and  course  of  the  vertebral artery as well as the percentage of abnormalities  of  the  variations  from  the point of view of surgery, angiography and in all non invasive procedures and for subsequent stabilization procedures of the cervical spine. Thorough knowledge of the anatomy of vertebral artery is mandatory to avoid potentially catastrophic injury to the vertebral artery.

 Materials and Methods

 The extra cranial course of vertebral artery was dissected in 25 formalin fixed cadavers  (both  sides)  in  Institute  of Anatomy, Madras Medical College. It included 17 male and 6 female cadavers and  2  fetal  cadavers.  Careful  dissection  was  carried out to find the details of variations on both sides and photographs were taken. Observation

 The vertebral artery (left) originated directly from arch of aorta in one adult specimen  (2%).  The  right  side  vertebral artery originated from the first part of sub- clavian artery in the same specimen (Fig. 1).

In the remaining specimens, the vertebral artery was found to originate from the first part of subclavian artery in the scaleno vertebral triangle.

Discussion

Gray (1901), Piersol (1930), Grant (1951), Romanes (1964) have reported that the vertebral artery arises from the first part of subclavian artery.

Shivkumar et al., (2010) has found an anomalous branching pattern of the aortic arch while dissecting a 55 year old male cadaver in which the left vertebral artery originated from aortic arch proximal to the origin of left subclavian artery. Jeyanthi et al., (2010) has reported an anomalous origin of left vertebral artery directly from aortic arch in between left common carotid and left subclavian arteries

Fig. 1    Photograph showing abnormal origin of vertebral artery

Aa-Aortic   arch,   BCT   -brachiocephalic  trunk, LCC-left common carotid, V-vertebral artery, LS- left subclavian Beeta Patasi et al., (2009) found an abnormal origin of left vertebral artery from arch of aorta between left common carotid and  left  subclavian  arteries,  during dissection of a 77 year old male cadaver.

Fig. 2    Comparative study of origin of vertebral artery from arch of aorta.

Soubhagya and Nayak et al., (2006) reported   in   1.6%   of   the   62   cadavers dissected that the left vertebral artery had its origin from arch of aorta.

Gorey et al., (2005) has stated that the most frequent variant is the left vertebral artery arising directly from arch of aorta between left common carotid and left subclavian arteries which accounts to about  2.4-5.8 percent.

Skandalaki (2004) has reported that in 4 percent of cases the vertebral artery originated from arch of aorta.

Panicker et al., (2002), Voster et al., (1998),  have  reported  that  the  vertebral artery originated from arch of aorta in 5 percent of cases

Cavdar and Arisan (1989) has quoted that   in   8.33   percent   of   cases,   the   left vertebral  artery  had  its  direct  origin  from arch of aorta.

Ranganathan and Jothi, (1987) has stated  that  the  vertebral  artery  originated from arch of aorta in 11.11 percent of cases.

Bergman and Affifi (1988) have illustrated   that   the   usual   branches   (80 percent) of arch  of aorta  were brachiocephalic trunk, left common carotid and left subclavian artery. If vertebral was present, more frequently it was left than the right vertebral. The variation of the four vessels has a frequency of about 5 percent.

Dassler and Anson (1959) have said that the left vertebral artery originated from the arch of aorta in 1.11 percent of the two bodies dissected.

Iyer (1917-1926) has recorded 6 out of 828 bodies (0.72%) in which the left vertebral artery originated from the arch of aorta.

In the present study, the origin of vertebral artery (left) from the arch of aorta was found in one specimen (2%) of the total fifty specimens dissected.

Conclusion

 The vertebral artery originated from the arch of aorta in 2% of cases in present study.

 Neurosurgical procedures like proximal  brachial  plexus  repair, scalenotomy, direct isolation of proximal vertebral artery requires good working knowledge of the first segment of vertebral artery. In angiographic or anatomic post mortem examinations, abnormal vertebral artery origins  are only incidental  findings, because, for most of the cases they are clinically asymptomatic. Nonetheless, these abnormalities are of diagnostic importance either prior to vascular surgery in the neck region or in cases of intravascular diseases such as arteriovenous malformations or cerebral aneurysms.

Annual convocation of maortic arch distal to left subclavian artery. AJNR,26: 93-95.The author would like to thank Dr.Christilda Felicia, the then HOD of Anatomy,  Madras  Medical  College, Chennai, for her support and valuable suggestions.