During routine dissection for teaching undergraduate medical students, we came across an arch of aorta with four branches in a male cadaver. From proximal to distal the branches were right common carotid, left common carotid, left subclavian and the anomalous right subclavian artery.The aberrant right subclavian artery took origin from the dorsal aspect of the arch of aorta as its last branch distal to the usual left subclavian artery, instead of its origin from brachiocephalic trunk. From its origin, the anomalous artery turned right and coursed between trachea and oesophagus inclining upwards and to the right to reach behind the right sternoclavicular joint and continued to supply the upper limb. Because of this variation there was no brachiocephalic trunk. Right subclavian artery appeared to be slightly larger and longer than the left subclavian artery. The trachea and oesophagus were positioned normally. No abnormalities were noted in the heart and other thoracic or abdominal viscera. The recurrent laryngeal nerves on both sides were found to have a normal course. The observations are depicted in [ An aberrant right subclavian artery arising as the last vessel of the arch of aorta is an uncommon anatomic anomaly with prevalence reported between 0.2% and 2.0%. In 80% of the cases the aberrant right subclavian artery takes a retro-oesophageal course to the right upper limb. During routine dissection of cadavers for teaching undergraduate medical students an anomalous Retrotracheal right subclavian artery which is a very rare vascular anomaly was encountered in a 35-year-old male cadaver. The artery arose as the last branch of the arch of aorta and coursed to the right between the trachea and oesophagus. The presence of this vascular anomaly could be an unusual cause of dysphagia and breathing difficulty. The clinical significance and embryological aspects of this vascular variant is discussed in this paper.anomalies, the clinician should be aware of their existence which could help in adequately managing the variations in emergency approaches to the arch of aorta and great vessels when imaging studies are not available [1]. The aberrant right subclavian artery (ARSA) arises from the arch of aorta or proximal descending aorta, and in 80% of the cases takes a retro-oesophageal course to the right upper limb [2].Autopsy based studies have revealed that the right subclavian artery can have an anomalous origin as the fourth branch of arch of aorta in 1-2% of the normal population [3]. Though 15% of the ARSA are reported taking a retrotracheal course [2], our literature search revealed only a single case [4] of retrotracheal right subclavian artery, but co-existing with a common trunk from the arch of aorta, which bifurcated into right vertebral artery and left thyroidea ima. In this context, we report a very rare case of RtRTSA (right Retrotracheal subclavian artery) arising distal to the left subclavian artery encountered during routine dissection for undergraduate medical teaching.Pharyngeal arches form during th...

Introduction Despite adequate preparation and meticulous pre-operative assessment, variations of the vascular anatomy of the aortic arch may lead to clinical dilemmas. In the present era, with the easy availability of imaging facilities, various anatomical variations can be found out prior to an interventional procedure. However, there are many countries including India where such facilities may still be not widely available. The purpose of this study was to assess the prevalence of these anatomical variants in patients undergoing Computerised Tomography (CT) chest with contrast. Methods This observational study involved patients who underwent CT chest with contrast as part of various clinical indications during a three-year period in a tertiary care centre in South India. Variations of the aortic arch and its branching pattern were studied in 4,000 chest CT images of patients referred to the radiology department. Results A total of 4,000 patients underwent CT chest with contrast during the study period. Twenty-seven variations were observed in these patients. They included aberrant right subclavian artery in seven patients, bovine arch in one patient, bovine origin of left vertebral artery from arch in one patient, bronchial artery of anomalous origin from arch in one patient, double aortic arch in one patient, and right-sided aortic arch in 16 patients. Conclusion The variant anatomy of the aortic arch has tremendous clinical significance, especially from the surgical standpoint. Anatomical variants can also cause difficulty during catheterization while performing endovascular interventions. Given the prevalence demonstrated in our study, imaging may be indicated prior to any procedure involving vascular access in order to prevent unwanted complications.

Accessory muscles of the neck are rare and are of clinical significance when present. During routine dissection of head and neck, two accessory muscles were found in the neck region of two cadavers, both male, one on the right and the other on the left. Both muscles took origin from the superior margin of the scapula and the insertion of the first muscle was to the clavicle, merging with subclavius and the second muscle got inserted to the first rib near the costochondral junction. This paper highlights the clinical significance and embryological aspects of such accessory muscles in the neck region.