Dr. G S Malipatil Place: Mangalore

From, Date: 14/09/2011 Dr. G S Malipatil Place: Mangalore Associate Professor, Department of Anatomy A J Institute of Medical Sciences, Kuntikana, Mangalore-575004

To, The Chairperson, A J Ethics Committee, A J Institute of Medical Sciences, Kuntikana, Mangalore- 575004 Subject: Submission of Post Graduate Dissertation protocol for A J Ethics Committee review and approval. Respected Sir/Madam, I am hereby submitting the Post Graduate Dissertation protocol of my Post Graduate Dr Roopa.R. Title "Anatomical study of the thyroid gland and its arterial supply”, for A J Ethics Committee review and approval of the study. Thanking you. Enclosures Protocol and Proforma Curriculum Vitae of Guide Curriculum Vitae of Post Graduate Yours sincerely,

Dr Roopa. R Dr G S Malipatil (Post Graduate) (Guide)

1 RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES. BANGALORE.

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

DR. ROOPA. R POST GRADUTE,

1 Name of the Candidate and DEPARTMENT OF ANATOMY Address A J INSTITUTE OF MEDICAL SCIENCES, MANGALORE – 575004

A J INSTITUTE OF 2 Name of the Institution MEDICAL SCIENCES, MANGALORE- 575004

3 Course of Study and Subject M.D (ANATOMY)

Date of Admission to the 4 31 MAY 2011 Course

5 Title of the Topic:

“ANATOMICAL

STUDY OF THE

THYROID GLAND

AND ITS ARTERIAL

SUPPLY”

6.0 BRIEF RESUME OF THE INTENDED WORK:

6.1 Need for the study

The thyroid gland, largest endocrine gland, brownish-red and highly

vascular, is placed anteriorly in the lower neck, level with the fifth cervical to the first

thoracic vertebrae. It usually weighs 25 g, but this varies. Estimation of the size of the

thyroid gland is clinically important in the evaluation and management of thyroid

disorders. (1)

It plays an important role in maintaining homeostasis and it has been

calculated that in a single minute, for each hundred grams of gland substance, about 560

ml of blood circulates through the gland and is five and half times more vascular than the

kidney. Apart from its significant endocrinal functions, it maintains basal metabolic rate

and is also susceptible to many diseases in human beings like thyrotoxicosis, hypothy-

roidism, cretinism, benign and malignant tumors, goiter and infertility.(1)

The current emphasis on the surgical management of the thyroid disease

has necessitated the understanding of the embryology and anatomy of the thyroid gland

3 and other vital structures in the neck, that helps the physician to perform proper physical

examination and also to the surgeon to perform successful thyroid surgeries.

Thus, a thorough knowledge of the anatomy of the thyroid gland, its mor-

phology and blood supply is a prerequisite for better understanding of the thyroid gland

and its diseases.

It is composed of two lateral lobes connected by a narrow median

isthmus thus giving an 'H' shaped appearance to the gland. The normal size of each lobe of

the thyroid gland has been described to be 5 cm long, its greatest transverse and antero-

posterior extent being 3 cm and 2 cm respectively. The isthmus measures about 1.25 cm

transversely as well as vertically.(12)

The major blood supply to the thyroid gland comes from two pairs of

vessels: the left and right superior thyroid arteries arising from the external carotid artery,

that may divide each into an anterior, a posterior and frequently a lateral branch; and the

left and right inferior thyroid arteries originating from the subclavian artery, dividing each

into a medial and a lateral branch. Thyroid arteries must be ligated carefully; the superior

thyroid artery tends to retract and fill the field with blood. The superior thyroid artery

should not be clamped above the upper pole of the thyroid because the external laryngeal

nerve may be injured. If the artery is clamped at the pole, a branch may escape, with

resulting hemorrhage. The entire superior pole, together with the artery, should be clamped

and ligated.(13)

4 Separation of the inferior thyroid artery from the recurrent laryngeal nerve

requires care. Where the nerve passes between branches of the artery, the individual

branches must be ligated and divided separately. Retraction of the artery may result in a

hasty attempt at hemostasis that will injure the recurrent nerve.(13)

A detailed knowledge about the Anatomy of Thyroid gland and its

arterial supply is very important for thyroid surgeries. As injury to the recurrent

laryngeal nerve which is intimately related to inferior thyroid artery, is one of the chief

hazards of thyroid surgery(14). The external branch of the superior laryngeal nerve (ELN)

is intimately associated with the superior thyroid artery (STA) in relation to the superior

pole of the thyroid gland, rendering it vulnerable to injury during the ligation of this vessel

during thyroidectomy(15). An accurate, anatomic knowledge of the course and variations

of the arteries is essential if nerve damage is to be avoided.

6.2 Review of Literature

Leonardo-Da-Vinci (1500) first described the beautiful butterfly shaped

thyroid gland in the neck.(2)

Vesalius (1543) gave the detailed description of the thyroid gland. He also

called the thyroid gland as laryngeal gland.(3)

Fabricius (1619) coined the term GOITRE which is a clinically evident

swelling of the thyroid gland in the neck region.(4)

Wharton (1656) coined the term THYROID (Thyros-a Greek word which

means shield like) because of the proximity of the gland to the thyroid cartilage.(5)

Neubauer (1786) first described the ARTERIA THYROIDEA IMA, which

5 is named after him.(6)

Alquie and Dubrueil (1847) observed a supernumerary inferior thyroid artery

which arose from subclavian near the origin of internal mammary artery. This artery

looped around the subclavian vein and passing very superficially entered the right lobe of

the thyroid gland.(7)

MaCalister (1868) reported, in his finding, that the superior thyroid artery

arose from external carotid artery as a common trunk along with lingual and facial

arteries.(8)

Sappey (1869) notes that the thyroidea ima is a supernumerary inferior

thyroid artery springing from the innominate arch, and adds that it has been very rarely ob-

served.(9)

Beaumanoir (1882) states that he has seen cases in which, with all the

thyroid arteries of a normal size, the thyroidea ima was of a large caliber and divided into

3 branches, the upper two ascending and taking up their positions, the one lateral to tra-

chea, the other lying in the midline and terminating in ramifications and anastomosing

with other thyroid arteries in the thyroid gland.(10)

Joshi SD and his colleague(2010) studied the thyroid glands in 90 male ca-

davers and they concluded that The average length of the right lobe was 4.32 cm, and the

left lobe was 4.22 cm. The thickness of the right lobe was 1.13 cm, and the left lobe was

1.18 cm. Pyramidal lobe was present in 34 (37.77%) cases, frequently arising from the left

lobe, while the levator glandulae thyroideae was present in 27 (30%) instances, mostly at-

tached superiorly to the body of the hyoid bone. The isthmus was absent in 15 (16.66%)

cases.(11)

6 Agenesis of the thyroid isthmus is rare in humans. previous studies has

reported varing incidence: 5 % to 10% by Pastor et al(12), 8% to 10% by Marshall (12).

Ranade et al in their study on anatomical variations of the thyroid gland reported a 33%

incidence of agenesis of the isthmus (12). According to the study by Braun et al, the

isthmus was missing in 4 cases of the 58 cadavers they studied (12). Won and Chung have

reported that in 3% of the cases studied, the isthmus was absent and the lateral lobes of the

thyroid were separated (12). The incidence in Northwest Indians is reported to be 7.9% in

gross specimens (12). The incidence was a little higher at 14.6% by Daksha dixit and

colleagues (2009) (12).

6.3 Objective of the Study

1.To study the Anatomy and morphological features of thyroid gland

thorough knowledge of the anatomy of the thyroid gland, its morphology and

blood supply is a prerequisite for better understanding of the thyroid gland and its diseases

2. To study the arterial supply of thyroid gland

Since there is an alarming number of table deaths in patients of thyroid disease

due to excessive and uncontrollable bleeding during thyroid surgeries, a thorough knowl-

edge of the arterial supply of thyroid gland is very essential for surgeons.

7.0 Materials and Methods:

7.1 Study type: Cross sectional study

7.2 Source of Data: The specimen for this study will be obtained from the department of

7 Anatomy, A.J.INSTITUTE OF MEDICAL SCIENCES, MANGALORE over the course

of study

7.3 Sample size: 25 Cadavers, aged between 30-50 years, from Department of Anatomy,

AJIMS, Mangalore. From September 2011 to September 2013.

7.4 Inclusion criteria: All embalmbed cadavers available during the study.

7.5 Exclusion criteria: thyroid gland with disease or pathological conditions are excluded

from the study

7.6 MATERIALS/INSTRUMENTS USED:

1. Forceps.

2. Scalpel.

3. Scissors

4. Thread and scale for measuring size of the gland

5. Digital camera.

7.7 METHODS

Dissection method was employed for this study. The infrahyoid group of

muscles were identified and reflected. The sternocleidomastoid muscle was displaced lat-

erally and thyroid gland was exposed. The fascia was removed from the lobes of the thy-

roid gland, exposing its arteries and veins. The lower part of the gland was lifted up to ex-

pose the lateral surfaces of trachea and oesophagus with recurrent laryngeal nerve in the

groove between them, along with the inferior thyroid artery. All the arteries of the thyroid

gland were exposed and observations were noted along with its morphological features.

Following morphological features noted.

8 Shape of the gland, Length and width of lobes, Presence or absence of pyramidal

lobe, Levator glandulae thyroidae and isthamus with its relation to the tracheal rings.

7.8 Does the study require any investigations or interventions to be conducted on

patients or other humans or animals? If so, please describe briefly.

7.9 Has the ethical clearance been obtained from your institution in case of 7.3?

Awaited

8. List of references

1. Standring S Gray’s anatomy: the anatomical basis of clinical practice, 39th edn. El-

sevier, Churchill Livingstone, Edinburgh, 2005:749-754.

2. Leonardo Da Vinci. The thyroid, 7th edition, Philadelphia 2: Lippincott –

Raven Publishers; 1500.

3. Vesalius. The thyroid. 7th edition, Philadelphia – 2 : Lippincott – Raven

Publishers; 1543.

4. Fabricius. The thyroid, 7th edition, Philadelphia – 2 : Lippincott – Raven

Publishers; 1619.

9 5. Wharton T. Adenographia; Sive, Glandularum totius corporis descriptio.

London : 1656.

6. Neubauer, OP. Anatom. Collecta, 1786

7. Alquie and Dubrueil. Quoted from Des anomalies arteries. JM Dubaris, 1847.

8. Macalister A. The superior thyroid artery. The medical press and circular. 1868.

9. Sappey, Traite ’d’ Anatomie, 1869.

10. Beaumanoir, Bull. de la Soc Anat, tome vii., 4e ser., 1882; 316.

11. Joshi.S.D and his colleagues. The thyroid gland and its variations- a cadaveric

study, 2010 Feb; 69(1):47-50.

12. Daksha dixit and colleagues, Agenesis of isthmus of thyroid gland in adult human

cadavers: a case series, 2009.

13. John E. Skandalakis, Stephen W. Gray, Joseph S. Rowes, Anatomical

Complications in General Surgery, Anatomy of the Thyroid Gland

14. William G. Armstrong, M.D.; J. William Hinton, M.D, Multiple divisions of the

Recurrent laryngeal nerve , AMA Arch Surg. 1951;62(4):532-539

15. D. Naidoo and his colleagues, Relation of the external branch of the superior

laryngeal nerve to the superior pole of the thyroid gland: An anatomical study, Clinical

Anatomy, 2007; 20 , Issue 5 :516–520.

10 9. Signature of the candidate

10. Remark of the Guide

DR. G. S. MALIPATIL Name and designation of Associate Professor, 11. Department of Anatomy, 11.1 Guide A J Institute of Medical Sciences, Mangalore-575004

11.2 Signature

11.3 Co Guide

11.4 Signature

DR.AJAY UDYAVAR Professor and Head, 11.5 Head of the Dept. Department of Anatomy, A J Institute of Medical Sciences, Mangalore- 575004

11.6 Signature

12.1 Remarks of the 12. Chairman and Principal

12.2 Signature

BUDGET ANALYSIS

11 A. Direct and Indirect Cost

a. Computer printouts - Rs. 3,000/-

b. Dissertation work - Rs. 5000/-

c. Photography and publications - Rs. 2000/-

B. Miscellaneous Rs. 3,000/-

C. Total Cost: - Rs. 13,000/-

TIME LINE

12 “ANATOMICAL STUDY OF THYROID GLAND AND ITS

ARTERIAL SUPPLY”

Principal Investigator: Dr. ROOPA. R

Guide: Dr. G. S. MALIPATIL Associate Professor, Department of Anatomy, A J Institute of Medical Sciences, Mangalore.

PHASE OUTLINE OF PLAN TIME PERIOD

September 2011 1. Identification of the problem

To 2. Review of Literature

November 2011 3. Making of Proforma I 4. Writing Synopsis

Jan 2012 – Aug 2013 Collection of data II Analysis of collected data

III Sep 2013- Nov 2013 Discussion and Thesis writing

13 CURRICULAM VITAE

Dr.’s Name : DR. G.S MALI PATIL

Date of Birth & Age : July 18, 1955 - 54 Years

Present Designation : Associate Professor

Department : Anatomy

College : A.J. Institute of Medical Sciences

City : Mangalore

Residential Address : Plot No.16, Bothra Colony Torvi Road, Bijapur

Phone & Fax Number With Code: Office : 0824-2225533

Residence : ----

E-mail address : ----

Mobile Number : 9845050273

Date of joining present institution : Nov 21, 2009 as Associate Professor

Qualifications :

Qualification College University Year Registration Name of the State No. of UG & Medical Council PG with date MBBS Karnataka Medical Karnatak 1984 24830, Karnataka College, Hubli, University dt. Apr 15, Medical Council 1986 MS J.J.M. Medical Kuvempu 1999 24830, Karnataka (Anatomy) College, University dt. May 20, 2004 Medical Council Davangere,

DM/M.Ch NA NA NA NA NA

14 Details of the previous appointments/teaching experience

Designation Department Name of Institution From To Total DD/MM/YY DD/MM/YY Experience in years & months Al Ameen Medical Aug 12, May 05, 1 Y ear 1987 1989 8 Months Tutor Anatomy 24 Days College, Bijapur B.L.D.E Associations Oct 25, 1990 Jun 29, 1992 1 Year 8 Months Medical College, Bijapur 5 Days Assistant Anatomy Mahatm Gandhi Jul 28, 1994 Oct 14, 1994 2 Months Lecturer 17 Days Missions Medial College,

Bombay Maharastra Institute of Nov 10, May 23, 6 Months 1994 1995 14 Days Medical Sciences, Latur Tutor Anatomy Sri Siddarhtha Medical Jun 03, 1995 Sep 11, 1996 1 Year 3 Months College, Tumkur 8 Days PG Cum Anatomy JJM Medical College, Sep 12, 1996 Feb 05, 1998 1 Year Tutor 4 Months Davangere 25 Days

Adichunchanagiri Inst. of Apr 30, 1999 Feb 16, 2000 9 Months Medical Sciences, Bellur 17 Days Assistant Anatomy Assistant Al Ameen Medial College, Feb 17, 2000 Nov 15, 2 Years Bijapur 2002 9 Months Professor Anatomy Navodaya Medical College, Nov 15, Mar 11, 3 Months

Raichur 2002 2003 25 Days Ass oci S.Nijalingappa Medical Mar 12, Jun 25, 2004 1 Year ate College, Hanagal 2003 3 Months 23 Days Professor A.J.Institute of Medical Jun 26, 2004 Apr 27, 2005 10 Month Sciences, Mangalore S.S. Institute of Medical Apr 28, 2005 Jan 18, 2006 8 Month Sciences & Research, 22 Days Davangere Seema DentalCollege & Apr 12, 2007 Jul 20, 2008 1 Year Hospital, Rishikesh 3 Months

15 9 Days

Shri Sathya Sai Medical Jul 21, 2008 Sep 30, 2008 2 Months College and Research Centre, 10 Days Tiruporur Al Ameen Medical College, Oct 01, 2008 Nov 20, 2009 1 Year Bijapur 1 Month 20 Days A.J.Institute of Medical Nov 21, 2009 Till Date Sciences, Mangalore

16 CURRICULAM VITAE

1. Personal details:

Name : Dr.Roopa. R Date of birth : Jul 10, 1981-29 years Present designation : PG/Tutor Department : Anatomy College : A. J. Institute of Medical sciences City : Mangalore Address : Land links paradise, A Block, # 201,konchady, Derebail Phone number : +91 9945729852 Email . ID : [email protected]

2.Qualifications:

Qualification College University year Registration no Name of the of UG & PG State Medical with date Council MBBS J. J. M. RGUHS Mar 72323 Karnataka Medical Bangalore 2004 20/09/2005 Medical college council

17 3.Details of the Previous appointments/Teaching experience:

Designation Department Name of From TO Total Institution DD/MM/YY DD/MM/YY experience in years/months Foundation Medicine/ Scarborough JUL 2007 AUG 2008 1 Year year doctor Paediatrics/ general 1 surgery hospital, UK Foundation Orthopaedi Bedford AUG APR 2010 8 Months year doctor cs/General hospital, 2009 2 practice UK PG/Tutor Anatomy A. J. May 2011 Til date Institute of medical sciences