Dissertation on “ANATOMICAL ANALYSIS OF ORIGIN, BRANCHING PATTERN AND VARIATIONS OF SUBCLAVIAN ARTERIES IN HUMAN CADAVERS’’ Submitted to THE TAMILNADU Dr. M. G. R. MEDICAL UNIVERSITY Chennai – 600 032 In partial fulfillment of the requirement for the award of degree of DOCTOR OF MEDICINE IN ANATOMY BRANCH - XXIII Submitted by Register Number: 201733351 KARPAGA VINAYAGA INSTITUTE OF MEDICAL SCIENCES AND RESEARCH CENTRE MADHURANTHAGAM TAMILNADU MAY 2020 1 CERTIFICATION This is to certify that “ANATOMICAL ANALYSIS OF ORIGIN, BRANCHING PATTEREN AND VARIATIONS of SUBCLAVIAN ARTERIES IN HUMAN CADAVERS’’ is a bonafide work of Dr. T.N.Pavazhakkurinji, in partial fulfillment of the requirements for the M.D Anatomy (Branch-XXIII) examination of The Tamilnadu Dr. M.G.R Medical University to be held on May 2020. Dr. T.L.Anbumani., M.D., M.S Dr. Sufala Sunil Vishwas Rao., MD Vice Principal and Principal, Head of the Department, Karpaga Vinayaga Institute of Medical Department of Anatomy, Medical Sciences and Research Centre Karpaga Vinayaga Institute of Medical Madhuranthagam. Sciences and Research Centre Madhuranthagam. 2 CERTIFICATION This is to certify that “ANATOMICAL ANALYSIS OF ORIGIN, BRANCHING PATTEREN AND VARIATIONS of SUBCLAVIAN ARTERIES IN HUMAN CADAVERS’’ is a bonafide work of Dr.T.N.Pavazhakkurinji in partial fulfillment of the requirements for the M.D Anatomy (Branch-XXIII) examination of The Tamilnadu Dr. M.G.R Medical University to be held on May 2020. Dr. T.L.Anbumani, M.D., M.S Head of the Department, Professor and Guide, Department of Anatomy, Karpaga Vinayaga Institute of Medical Sciences and Research Centre. Madhuranthagam. 3 DECLARATION I, Dr.T.N.Pavazhakkurinji hereby declare that this dissertation “ANATOMICAL ANALYSIS OF ORIGIN, BRANCHING PATTEREN AND VARIATIONS OF SUBCLAVIAN ARTERIES IN HUMAN CADAVERS’’ is a presentation of my own work and that it has not been submitted anywhere for any award. Wherever contributions of others are involved, every effort is made to indicate this clearly, with due reference to literature and discussions. This work was done under the guidance of Professor Dr. T.L.Anbumani, MD., M.S., at Karpaga Vinayaga Institute of Medical Sciences and Research Centre, Madhuranthagam. Candidate’s Name: Dr. T.N.Pavazhakkurinji Candidate’s signature: Date: In the capacity as guide for the candidate’s dissertation work, I certify that the above statements are true to the best of my knowledge. Dr.T.L.Anbumani. MD., M.S., Head of Department, Professor and Guide, Department of Anatomy, Karpaga Vinayaga Institute of Medical Sciences and Research Centre, Madhuranthagam 4 ACKNOWLEDGEMENT First of all I would like to thank our beloved Professor T.L.Anbumani M.D, M.S., Vice principal and Head of the department for guiding and supporting me over the years. You have set an example of excellence as a Mentor, Instructor and Role model. I would like to express my sincere and heartfelt Gratitude to respected Managing director Prof.Dr.R.Annamalai M.S. and Dr.Sufala Sunil Vishwas Rao M.D. for permitting and extending their valuable support in conducting the study. I would like to thank Dr.A.Thamari selvi M.D. Assistant Professor for all of her guidance throughout this process; her discussions, ideas and feedback have been absolutely invaluable. My sincere thanks to all the Faculty Members in the Department of anatomy for their valuable guidance and support during this study. I would like to thank my Fellow graduate students, Technicians and supporting staffs who contributed to this study. I am very grateful to all of you. My sincere thanks to my family members and friends for their moral support given in all the time in completing this dissertation. 5 CONTENTS CHAPTER PAGE TITLE NO. NO. 1. INTRODUCTION 1 2. AIM AND OBJECTIVES 14 3. REVIEW OF LITERATURE 15 4. MATERIAL AND METHODS 43 5. OBSERVATION AND RESULTS 45 6. DISCUSSION 74 7. SUMMARY AND CONCLUSION 90 BIBLIOGRAPHY 95 ANNEXURES 110 a) PLAGIARISM ANALYSIS REPORT 111 b) PLAGIARISM SCREEN SHOT REPORT 112 c) DR.MGR MEDICAL UNIVERSITY 113 PLAGIARISM VERIFIED GUIDE CERTIFICATE d) INSTITUTIONAL ETHICAL COMMITTEE 114 APPROVAL CERTIFICATE e) ABBREVIATIONS 115 6 INDEX FOR TABLES 7 INDEX FOR TABLES TABLE PAGE TITLE NO. NO. 1. NUMBER OF BRANCHES OF SUBCLAVIAN ARTERY 45 2. NUMBER OF BRANCHES OF FIRST PART OF 46 SUBCLAVIAN ARTERY 3. ORIGIN OF VERTEBRAL ARTERY 47 4. LEVEL OF VERTEBRAL ARTERY ENTREING 47 TRANSVERSE FORAMINA 5. ORIGIN OF INTERNAL THORACIC ARTERY 48 6. NUMBER OF BRANCHES OF THYROCERVICAL 52 TRUNK 7. ORIGIN OF INFERIOR THYROID ARTERY 56 8. RELATION OF RECURRENT LARYNGEAL NERVE TO 57 INFERIOR THYROID ARTERY 9. PRESENCE /ABSENCE OF TRANSVERSE CERVICAL 59 ARTERY 10. ORIGIN OF SUPRASCAPULAR ARTERY 60 11. BRANCHES OF COSTOCERVICAL TRUNK 64 12. PRESENCE/ABSENCE OF BRANCHES IN THIRD PART 65 OF SUBCLAVIAN ARTERY 13. ORIGIN OF DORSAL SCAPULAR ARTERY 65 14. RELATION OF DORSAL SCPAULAR ARTERY WITH 67 BRACHIAL PLEXUS 15. COMPARISON OF VERTEBRAL ARTERY ORIGIN 75 8 INDEX FOR CHARTS FIGURE PAGE TITLE NO. NO 1 PERCENTAGE OF BRANCHES OF SUBCLAVIAN 46 ARETRY 2. PERCENTAGE OF BRANCHES OF THYROCERVICAL 52 TRUNK 3. PERCENTAGE OF RELATION OF RECURRENT 57 LARYNGEAL NERVE WITH INFERIOR THYROID ARTERY. 4. PERCENTAGE OF TRANSVERSE CERVICAL ARTERY 59 PRESENCE AND ABSENCE 5. ORIGIN OF SUPRASCAPULAR ARTERY 61 6. PERCENTAGE OF DORSAL SCAPULAR ARTERY 67 ORIGIN 7. RELATION OF DORSAL SCAPULAR ARTERY WITH 69 BRACHIAL PLEXUS 8. COMPARATIVE CHART OF VERTEBRAL ARTERY 76 ORIGIN 9. COMAPARTIVE CHART OF ORIGIN OF INTERNAL 78 THORACIC ARTERY FROM THYROCERVICAL TRUNK 10. COMPARATIVE CHART OF THYROCERVICAL 80 TRUNK HAVING TWO BRANCHES 11. COMPARATIVE CHART OF RELATION OF 82 RECURRENT LARYNGEAL NERVE WITH INFERIOR THYROID ARTERY 9 FIGURE PAGE TITLE NO. NO 12. COMPARATIVE CHART ON ORIGIN OF 83 TRANSVERSE CERVICAL ARTERY FROM THYROCERVICAL TRUNK 13. COMPARATIVE CHART FOR VARIOUS ORIGIN OF 85 SUPRASCAPULAR ARTERY 14. COMPARATIVE CHART FOR ABSENCE OF DEEP 86 CERVICAL ARTERY 15. COMPARATIVE CHART OF ORIGIN OF DORSAL 88 SCAPULAR ARTERY 16 MASTER CHART 70-73 10 INDEX FOR FIGURES FIGURE PAGE TITLE NO. NO 1. ORIGIN OF VERTEBRAL ARTERY FROM ARCH OF 49 AORTA 2. INTERNAL THORACIC ARTERY ORIGIN FROM 50 THYROCERVICAL TRUNK 3. THYROCERVICAL TRUNK WITH TWO BRANCHES 53 4. THYROCREVICAL TRUNK WITH FIVE BRANCHES 54 5. ABSENCE OF THYROCERVICAL TRUNK 55 6. RECURRENT LARYNGEAL NERVE BETWEEN THE 58 BRANCHES OF INFERIOR THYROID ARTERY 7. SUPRASCAPULAR ARTERY ORIGINATING FROM 62 THIRD PART OF SUBCLAVIAN ARTERY 8. SUPRASCAPULAR ARTERY FROM AXILLARY 63 ARTERY 9. DORSAL SCAPULAR ARTERY FROM CERVICO 66 SCAPULAR TRUNK 10. DORSAL SCAPULAR ARTERY BELOW THE TRUNKS 68 OF BRACHIAL PLEXUS 11 CHAPTER – I INTRODUCTION SUBCLAVIAN ARTERY AND ITS BRANCHES 12 INTRODUCTION The human body itself have countless difference in structure and many of these variations have been documented in anatomical literature. One such structure is subclavian artery and its arterial branches originating from it. Subclavian artery and its branches reside in compact and complex anatomical space. Subclavian artery’s such location makes it difficult exposure during surgery. Also there is much uncertainty and variability in literature of subclavian artery. With recent increase in the use of CT, MRI and angiography it has been pointed that accurate understanding of morphology of normal subclavian artery, and its ramifications are essential for accurate diaganosis1. Sternocleidomastoid and trapezius muscle are frequently used as musculocutaneous flap in reconstructive surgery. These muscles are supplied by branches of subclavian artery, but the literatures on these arteries are limited2.For these purpose a study is conducted for origin, ramification of subclavian artery. In the root of neck the key orienting structure is Scalenus anterior muscle. It arises from anterior Tubercles of cervical vertebrae C3-C6 and inserted into scalene tubercle on superior aspect of first rib. The main vascular trunks to head and neck and upper extremity enter root of neck. 13 The aorta is largest artery in human body. The aorta arises from left ventricle of heart to deliver oxygenated blood. It is divided into ascending aorta, arch of aorta, and descending aorta. The ascending aorta runs superiorly from its origin to the arch of aorta at the level of T4-T5. The arch of aorta is located in superior mediastinum, progressing posterior to posterior mediastinum as descending aorta. The common branching pattern of aortic arch in human consists of three vessels, Brachiocephalic trunk, left common carotid artery and subclavian artery. Vascular anomalies occur as a failure in the congenital development of primordial aortic arch3. These aortic vessels are important in providing vascularisation to the head and neck region. Occlusion of these vessels may lead to impairment of neurological functioning. Origin of Subclavian artery On right side subclavian artery arise from brachiocephalic trunk behind right sternoclavicular joint. On left side it arises from arch of aorta. Each subclavian artery divided into three parts by scalenus anterior muscle. Scalenus anterior muscle originates from C3 to C6 vertebrae, inserted into scalene tubercle present in first rib positioned anterior to subclavian artery. Scalenus anterior muscle divides the artery into three parts. First part extends from origin to medial border of scalenus anterior. Second part behind the muscle. Third part extends from lateral border of scalenus anterior to outer border of first rib. First part of 14 both side have separate description and relation .C5 –T1 nerve roots of brachial plexus originate from cervical transverse foramina of C5-C7 and T1,anterior primary rami of these roots unite to form upper, middle and lower trunks. Lower trunks is closely associated with Subclavian artery.4 First part: Right subclavian artery arises from right brachiocephalic trunk. The relation are in front by superficial fascia, platysma, deep fascia, clavicular origin of sternocleido mastoid, sternohyoid, sterno thyroid.Subclavian artery crossed by internal jugular vein, vagus nerve, subclavian loop of sympathetic trunk.