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SECTION VI — Thyroid Gland and Its Disorders
Risk factors for development
of papillary cancer
1. Ionizing radiation. Low-dose radiation for head and
neck especially several years previously.
As a fallout from nuclear exposure as happened in
Chernobyl accident, and Hiroshima and Nagasaki.
Ionizing radiation causes gene mutation.
2. Familial. Five to ten per cent of patients with papillary
thyroid carcinoma (PTC) have family history of thyroid
cancer. Cowden syndrome consists of multiple hamarto-
mas, breast tumours, skin tags and follicular or papillary
cancer. Gardner’s syndrome consists of familial colonic
polyposis with thyroid cancer. Papillary carcinoma is
seen in areas with adequate iodine intake unlike follicular carcinoma which is more common in low-iodine
intake areas with endemic goitre. Tumour may be multicentric in origin either because of intrathyroidal lymphatic spread or de novo multicentric origin.
Clinical presentation
PTC may present with the following symptoms:
1. An asymptomatic mass in the thyroid.
2. Metastatic nodes in the neck. About one-third of patients have palpable neck nodes.
3. Depending on local invasion, mass in the thyroid may
produce symptoms of local invasion of strap muscles,
trachea, oesophagus or laryngeal nerves.
4. Pulmonary or bone metastases with or without a mass
in the neck; occult primary of the thyroid may present
with metastases.
Diagnosis
History, clinical examination and FNAC are important.
Ultrasound of the thyroid and the neck is important to
look for other lesions in thyroid (as the disease is multifocal) and also involvement of neck nodes. Thyroid function tests may reveal hyperthyroidism though most of
the patients are euthyroid. X-ray chest may show pulmonary metastases. CT/MRI may be required for extent of
disease or retrosternal extension.
Treatment
1. Microcarcinoma, which is less than 1.5 cm, hardly palpable clinically with no capsular invasion or cervical
nodes and mostly discovered incidentally at the operation, is treated with lobectomy with isthmusectomy.
2. Intrathyroidal tumour more than 1.5 cm with no nodule on contralateral side and no palpable neck nodes,
also requires a lobectomy with isthmusectomy.
3. Gross disease in both lobes seen on preoperative ultrasound or on palpation at the time of operation with no
cervical nodes requires a total or near total thyroidectomy.
4. High-risk patients require total thyroidectomy.
5. Tracheal invasion requires tracheal segmental excision
and repair in addition to the excision of growth.
6. Cervical lymph node dissection is done if nodes are
palpable. There is no role of elective neck dissection.
Follow-up
After total thyroidectomy, disease may sometimes be
left in the ligament of Berry, pyramidal lobe or superior
poles of thyroid and requires postoperative radioiodine
ablation.
FOLLICULAR CARCINOMA
It arises from the follicular cells of the thyroid. It constitutes about 10-15% of thyroid malignancies. Usually
presents at age 50 and is more common in females (3:1).
Clinically, it presents either as a solitary thyroid nod-
ule or a rapid increase in a pre-existent nodule.
More often it spreads by blood stream and thus may
have distant metastases at presentation in 10-15% of patients. Unlike papillary cancer, lymph node involvement
is less common and if it occurs, indicates extensive spread
locally.
FNAC may be reported as follicular neoplasm. It is only
after surgical removal of the specimen that carcinoma can
be diagnosed as the latter requires capsular or vascular
invasion.
Treatment
1. If diagnosed as follicular neoplasm on FNAC (not can-
cer), lobectomy with isthmusectomy should be done.
Include also the pyramidal lobe.
If lobectomy specimen is reported as carcinoma, com-
pletion of thyroidectomy is done i.e. removal of other
lobe as well. It can be followed by radioiodine scan and
ablation of metastatic disease.
2. If diagnosed follicular carcinoma on FNAC, total thy-
roidectomy should be performed.
3. If nodule size is greater than 4 cm in an elderly person
and is reported as follicular neoplasm, perform total
thyroidectomy due to the risk of its being carcinoma.
Neck dissection is done only if nodes are palpable. Prophylactic neck dissection has no role.
Prognosis of follicular carcinoma is poor if age at presentation is more than 50 years, size is more than 4 cm or
distant metastases are present.
HURTHLE CELL CARCINOMA
It is also called oncocytic carcinoma. Oncocytes are large
cells which are rich in mitochondria and stain pink. It
may be multifocal, bilateral and spreads to regional nodes
or sends distant metastases. Its behaviour is more aggressive than that of follicular carcinoma. These tumours do
not take up radioactive iodine as avidly as seen in follicular carcinomas.
Aggressiveness of thyroid cancer: Hurthle cell → Follicular → Papillary cell cancer.
Clinically, it presents as a thyroid nodule. Mean age at
presentation is slightly more than in follicular carcinoma.
FNAC may show Hurthle cells but cannot differentiate
benign Hurthle cell adenoma from carcinoma. It is only
on histologic findings of capsular or vascular invasion
that diagnosis of carcinoma can be made.
Treatment
Hurthle cell adenoma is a benign tumour and requires
lobectomy and isthmusectomy only. If capsular or vascular invasion is seen on histopathology a completion thyroidectomy should be done.
Chapter 66 — Thyroid Gland and Its Disorders
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If it is reported as Hurthle cell carcinoma on FNAC a
total thyroidectomy with clearance of paratracheal nodes
is done. If lateral nodes are also palpable, a neck dissection is performed.
In the follow-up, technetium scan should be done as
Hurthle cells do not take up radioiodine.
Prognosis is worse than in follicular or papillary carcinoma.
ANAPLASTIC CARCINOMA
It represents less than 5% of all thyroid cancers. Mostly
affects patients in the age group of 60-80 years, is very
rare before 50 years. Affects women more than men in the
ratio of 3:2. It has an aggressive behaviour; grows rapidly
to involve the surrounding structures causing hoarseness,
stridor, dyspnoea, dysphagia and thoracic inlet obstruction. Cervical lymph node involvement is seen in 80%
of patients at presentation. Due to its aggressive nature,
cervical nodal mass and thyroid mass may fuse together
and it may be difficult to distinguish the two. Unlike thyroid lymphoma, which is painless, anaplastic carcinoma
causes a painful mass. Distant metastases can lodge in
long bones and brain and are present in 50% of patients
at presentation.
Treatment is unsatisfactory. Median survival is only a
few months. Surgery, radiation and chemotherapy have a
limited role. Palliation in the form of tracheostomy and
nutritional support is the only treatment.
MEDULLARY CARCINOMA
It arises from the parafollicular C cells of the thyroid
which are neuroectodermal in origin. Hence it may be
associated with other tumours of neuroectodermal origin
as in MEN IIa and MEN IIb. Most medullary carcinomas
are located in the middle and upper thirds of thyroid
lobes which are derived from the ultimobranchial bodies having C cells. They comprise about 5% of thyroid
malignancies.
Clinically, medullary carcinoma presents with a neck
mass with cervical nodes in the age group of 50-60 years.
Both sexes may be equally involved. As tumour is aggressive and invades locally, it causes pain, dyspnoea, dysphagia and hoarseness. Distant metastases may be seen in the
mediastinum, lung and bone at the time of presentation
in about half the cases.
TABLE 66.5 MULTIPLE ENDOCRANIAL NEOPLASIA
SYNDROME
• MEN I
• Hyperparathyroidism
• Pituitary tumour
• Pancreatic tumour (islet cell adenoma)
• MEN IIA (Sipple syndrome)
• Medullary thyroid cancer
• Pheochromocytoma (50%)
• Hyperparathyroidism (30%)
• Hirschsprung disease
• MEN IIB (Rare)
• Medullary thyroid cancer
• Pheochromocytoma
• Mucosal neuromas
• Marfanoid habitus
• Intestinal ganglioneuromas
Medullary carcinoma can be sporadic (more common)
or familial. The latter may be associated with MEN type
IIA and IIB (see Table 66.5) or without any endocrinopa-
thy (Figure 66.6).
Parafollicular cells secrete calcitonin and a carcinoembryonic antigen. Levels of calcitonin have been used in
the diagnosis of medullary carcinoma and in postsurgical
follow-up for recurrent or residual tumours.
Sporadic carcinoma presents as a unifocal lesion and is
not associated with other endocrinal pathologies.
Familial type presents at a younger age and is multicentric and bilateral. Familial type is of two types: one,
without association with other endocrinopathy and the
other associated with multiple endocrinopathies (MEN
type IIA and IIB) (Table 66.5).
A variant of medullary thyroid cancer is mixed medul-
lary cancer in which both follicular and C cells are seen.
Its behavior and treatment are same as medullary cancer.
Diagnosis is made on FNAC and elevated levels of calcitonin. Patients should be tested for mutation of RET
proto-oncogene which is present in peripheral lymphocyte DNA. Investigate also for other endocrinopathies
by measuring levels of serum calcium (for parathyroid)
and 24-h urine for catecholamines/metanephrine for
pheochromocytoma. Relevant imaging studies are also
done.
Screening of all first degree relatives and children is
required for RET-proto-oncogene mutations in cases of
Figure 66.6. Types of medullary cancer of thyroid.
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SECTION VI — Thyroid Gland and Its Disorders
medullary cancer associated with MEN type IIA and IIB.
All children with medullary cancer and those with MEN
type IIA should undergo thyroidectomy by age of 6 years.
Those with MEN type IIB should have surgery within first
year of life.
Treatment
Because of aggressive nature and multicentricity of the
lesion, total thyroidectomy is the treatment of choice. It
is combined with removal of nodes in level VI even if not
involved. However, if level VI nodes are involved, a comprehensive neck dissection (level II–V) is also performed.
If primary lesion is more than 2 cm, ipsilateral elective
neck dissection should be done. Level VII nodes should
also be removed.
Pheochromocytoma, if associated, should be removed
before thyroidectomy to avoid hypertensive crisis during
operation.
Postoperative follow-up is done by measuring calcitonin levels for any residual, recurrent or metastatic
disease.
Radioactive iodine and chemotherapy are not effective. Role of external beam radiation is also controversial.
LYMPHOMA
Most of the thyroid lymphomas are B-cell non-Hodgkin
type. They are seen in the age group of 60-80 years and
are more common in females (ratio of 3:1). Pre-existing
Hashimoto disease predisposes to lymphoma formation.
Clinically, a lymphoma presents like an anaplastic
thyroid cancer, with rapidly growing painless thyroid
mass which invades the surrounding structures leading
to hoarseness, stridor, dyspnoea, dysphagia and thoracic inlet obstruction. Cervical lymph nodes are enlarged.
Lymph node enlargement can occur in other regions of
body as well depending on the stage of disease. Patient is
often hypothyroid.
Histologically, lymphoma needs to be differentiated
from anaplastic carcinoma and Hashimoto disease by immunohistochemistry. Therefore it may require FNAB or
isthmusectomy to have enough tissue; the latter also decompresses the trachea to relieve airway obstruction.
Treatment depends on the stage of disease. Surgery, external beam radiation and chemotherapy have been used
depending on the stage. Role of surgery may be limited to
open biopsy only or a tracheostomy or removal of early
disease when it is localized to thyroid (stage I) or thyroid
and the neck nodes (stage II). Radiotherapy can also be
used in such cases of stage I and II but for a disease of
stage III (both sides of diaphragm) or stage IV (disseminated disease) radiotherapy and chemotherapy are combined.
METASTASES TO THYROID
Malignant disease of breast, kidney, lung, and squamous
cell cancers of head and neck and melanomas can send
metastases to the thyroid and present as a nodule. FNAC
is helpful in diagnosis. Metastases from undifferentiated
cancers may be difficult to distinguish from anaplastic
carcinoma of the thyroid.
THYROID NODULE AND ITS
MANAGEMENT
Clinically, palpable nodules are seen in about 4-7% of
people. Their incidence increases as the age advances.
About 5-10% of the nodules may be malignant. Risk of a
nodule being malignant increases if the patient received
radiation in childhood. Incidence of a thyroid nodule being malignant also increases in patients over the age of
50-60 years.
A solitary thyroid nodule can be:
1. Colloid nodule (also called adenomatous nodule)
2. Adenoma
(a) Follicular adenoma
(b) Hurthle cell adenoma
3. Thyroid cyst (cystic change in colloid nodule or follicular adenoma)
4. Regenerative nodule
5. Dominant nodule (in multinodular goitre)
6. Autonomous (or toxic) nodule
7. Carcinoma
8. Metastatic deposits in thyroid (rare)
The main consideration in a thyroid nodule is to pick
up cases of carcinoma. Of all the palpable nodules, only
about 5-10% will be malignant.
Colloid nodule (or adenomatous nodule)
It is a benign condition, clinically resembling an adenoma, hence called adenomatous. It is due to hyperplasia of
follicular cells with the follicles filled with colloid. TSH
level is normal but hyperplasia of follicular cells is attributed to their being more sensitive to the action of TSH.
Lowering the TSH by administering exogenous thyroid
hormone (suppressive therapy) is used to treat such nodules but it is difficult to predict which nodules will respond to this form of therapy.
Follicular adenoma
It is a well-demarcated, encapsulated and true benign
neoplasm of follicular cells. It may undergo cystic degeneration, haemorrhage, calcification and fibrosis. It is difficult to differentiate it from follicular carcinoma on FNAC
because diagnosis of carcinoma requires vascular and/or
capsular invasion which is possible only on histology of
the mass removed.
Hurthle cell adenoma
Hurthle cells are oncocytes, rich in mitochondria. Like
follicular adenoma, it is also well-demarcated and encapsulated. An adenoma of Hurthle cell cannot be differentiated from Hurthle cell carcinoma on FNAC as the diagnosis of latter requires capsular and/or vascular invasion.
Thyroid cyst
About one-fourth of the thyroid nodules present as a cyst
or a cystic component in a nodule. It may be:
1. Simple thyroid cyst.
2. Haemorrhage in colloid nodule.
3. Papillary carcinoma with cystic change.
4. Parathyroid cyst.
5. Thyroglossal duct cyst.
Chapter 66 — Thyroid Gland and Its Disorders
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Figure 66.7. Diagnosis of the thyroid cyst.
379
Cystic nature of the thyroid mass can be identified
on ultrasound. Aspiration of clear fluid is indicative of
parathyroid cyst; fluid in such cases is tested for parathormone. Aspiration of brown fluid indicates haemorrhage
in the colloid nodule; red or bloody aspirate indicates
papillary cancer. FNAC should be done from the solid
component of the cyst under ultrasound guidance in
masses with both solid and cystic components. Thyroid
cysts larger than 4 cm are surgically excised; those smaller
than 4 cm are aspirated and suppressed with thyroid hormones (suppression therapy) and if they recur surgical
excision should be done (Figure 66.7).
Dominant nodule
Clinically, only one nodule is palpable though gland has
multiple nodules. Other nodules are diagnosed at ultrasound or direct palpation of gland at the time of the surgery. A dominant nodule seen in a multinodular goitre
may be malignant.
Regenerative nodule
It is seen in Hashimoto disease. Patient is hypothyroid
and TSH level is either raised or at the upper limit of normal. TSH stimulates the follicular cells to form a nodule.
Autonomous (or toxic) nodule
It is a single hot nodule in the thyroid and is so-called because it functions independently of TSH. It is due to mutation in TSH receptors on follicular cells, which function
independently and cause proliferation of follicular cells
and their enhanced function. Thyroid scan is diagnostic which reveals high uptake by the nodule but the rest
of the gland shows low uptake. It causes thyrotoxicosis
which is usually mild. TSH level is low. Treatment is total
lobectomy with isthmusectomy or thyroid ablation with
radioactive iodine; the former being preferred. In Europe,
it has been treated by injection of ethanol into the nodule under ultrasound guidance especially in patients unfit
for surgery or unwilling for radioiodine therapy. Ethanol
injection may need to be repeated in some patients. It
has the risk of diffusion to recurrent laryngeal nerve and
cause its paralysis.
Carcinoma
Thyroid malignancies may present as a solitary nodule
(see Table 66.6).
EVALUATION OF THYROID NODULE
1. History is important. Patient may present with large
thyroid nodule or be referred because an incidental
TABLE 66.6 SOLITARY NODULES WITH HIGH RISK
FOR MALIGNANCY
• Age< 20 and > 45 years
• Malegender
• Historyofpreviousradiationtoneck
• Familyhistoryofthyroidcancer
• Rapidgrowth
• Pain
• Compressiveorinvasivefeaturessuchasstridor,dyspnoea and
dysphagia
• Fixedandhardlesion
• Sizeofnodule> 4 cm
• Recurrentorrapidlyllingcystafteraspiration
• NodulesthatoccurinGraves’orHashimotothyroiditis
nodule is discovered on imaging. A solitary thyroid
nodule or a dominant nodule in a multinodular goitre
has the risk of being malignant. Risk factors for a nodule being malignant are shown in Table 66.6.
2. Physical examination. Concern for malignancy increases when
(a) Nodule is larger than 4 cm.
(b) Fixed to skin or underlying structures.
(c) Firm to feel.
(d) There are associated lymph nodes in the neck at
levels VI, II, III, IV and V.
(e) Laryngoscopic examination reveals fixed vocal cord.
3. Thyroid function. TSH, T4 and T3 are measured. They
are normal in a colloid nodule. Fall in TSH or rise of
T4 (total or free) and T3 indicate hyperfunctioning
nodule. Estimation of calcitonin level is indicated in
patients with family history of medullary carcinoma.
4. Ultrasound of thyroid. It is a useful test and identifies:
(a) Small nodules which cannot be palpated or nod-
ules in obese neck.
(b) Multiple nodules.
(c) Accurate size of nodule(s) and their location.
(d) Cystic or solid nature of nodules.
(e) Associated cervical lymph nodes.
(f) Vascularity of thyroid gland or nodules.
5. Thyroid scan. Technetium (
99m
Tc),
123
I and
131
I have
been used. It can differentiate between cold and hot
nodules. Most of the nodules are cold (80%) with only
5% being hot. Chances of malignancy in cold nodules
is about 10% while it is only 1% in hot nodules.
6. Fine needle aspiration cytology or biopsy (FNAC/
FNAB). Sensitivity and specificity of FNAC for diagnosis of thyroid masses is high-up to 90%. Ultrasoundguided FNAC/FNAB further increases the accuracy of
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SECTION VI — Thyroid Gland and Its Disorders
Figure 66.8. Management of thyroid nodule.
cytologic diagnosis. The aspiration may be reported
as benign, malignant or indeterminate. Follicular or
Hurthle cell tumours are reported as neoplasms because FNAC cannot differentiate between benign and
malignant lesions. Insufficient material collected on
FNAC may require repeat procedure or observation
and periodic evaluation. If risk factors for malignancy
exist, surgery may be required (Figure 66.8).
7. CT/MRI. They are not used routinely but are very
helpful in evaluating the size and extent of retrosternal
goitres. It may also show degree of tracheal compression.
MANAGEMENT OF THYROID NODULE
Depends on diagnosis made (see Figure 66.8).
Suppressive therapy for nodules
Enlargement of thyroid and formation of nodule(s) are
dependent upon trophic effect of TSH on thyroid cells.
Suppressing TSH with exogenous T4 is assumed to reduce nodule formation. A nonrandomized study showed
reduction of nodule in 30% of patients. But other studies
which were randomized did not corroborate it. There is
also no consensus how long to give therapy, how much
to suppress TSH, whether nodule will decrease or only
stabilize in size. Suppressive therapy has also the risk of
cardiac arrhythmias and decrease in bone density in such
patients who are usually euthyroid. In general suppressive therapy is not preferred.
THYROID SURGERY
Types of thyroid surgery are listed in Table 66.7
INDICATIONS
Broadly there are four indications for thyroid surgery
which can be remembered by four C’s.
1. Cancer thyroid.
2. Suspicion of cancer, e.g. thyroid neoplasm on FNAC
and thyroid nodule with risk factors.
Chapter 66 — Thyroid Gland and Its Disorders
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TABLE 66.7 TYPES OF THYROID SURGERY
Type Description Diagram Indication
Hemithyroidectomy or thyroid
lobectomy
Complete removal of one thyroid lobe with
isthmus
• Benignnodule
• Intrathyroidalcancer
381
Subtotal thyroidectomy Removal of more than one half of the thyroid
lobeoneachsideandalsoisthmusleaving
3goneachsides
Near total thyroidectomy Removal of complete thyroid lobe on one
sidealongwithisthmusandalmost
complete removal of lobe on other side
leavingonlyasmallpart(1g)ofitto
protect parathyroid and RLN
Total thyroidectomy Complete removal of both lobes and isthmus • Medullarycarcinoma
Isthmusectomy Complete removal of isthmus
Completion thyroidectomy Removalofremainingthyroidgland
to convert it into total or subtotal
thyroidectomyafterominoushistologyis
received
• Thyrotoxicosis
• Multinodulargoitre
Forsomemalignancies
• Hurthlecellcarcinoma
• Follicularcarcinoma
• High-riskpatientwithpapillary
carcinoma
• Noduleofisthmus
• Fordiagnosticbiopsy
If total lobectomy proves
malignantwithcapsular/
vascular invasion, other lobe
isalsoexcised.
3. Compressive symptoms, e.g. pressure on trachea or
oesophagus or veins causing dyspnoea or dysphagia.
Substernal extension causing thoracic-inlet syndrome
with positive Pemberton’s sign, i.e. raising the arms
above head causes respiratory distress, suffusion of face
and neck vein engorgement.
4. Cosmetic. A large nodule or a multinodular goitre.
To this may be added the fifth indication of hyperthy-
roidism, such as autonomous nodule or Graves’ disease.
PREOPERATIVE WORK-UP
1. Detailed history.
2. Physical examination.
3. Thyroid profile. TSH, T4 and T3.
4. Indirect laryngoscopy. For vocal cord paralysis or a
compensated vocal cord function.
5. FNAC. To know the histology.
6. TPO antibodies. When indicated for Graves’ disease.
7. Level of calcitonin. When medullary carcinoma is
suspected.
8. Serum calcium level. As a baseline.
9. Ultrasound thyroid/neck. For size and number of thyroid nodules and status of lymph nodes in the neck.
10. Thyroid scan. If indicated, e.g. for autonomous nodule.
11. CT chest. For retrosternal goitre.
12. Investigations for surgical fitness:
• Haemogram.
• Urine; routine and microscopic.
• Blood sugar (F).
• Blood urea/creatinine.
• X-ray chest.
• ECG.
• Cardiac echo (if required).
ANAESTHESIA
General with endotracheal intubation.
POSITION
Supine with neck extended.
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STEPS OF OPERATION
Incision
A horizontal incision in the skin crease below the collar line. In females with heavy breasts incision is a bit
higher so that it does not drag to manubrium to cause
hypertrophic scar. Incision is made from one sternomastoid muscle to the opposite one. It cuts through skin and
subcutaneous tissues.
Elevation of flaps
Platysma is then cut in the same incision with diathermy
and the upper and lower flaps are developed. The upper
flap should reach the thyroid notch and the lower one up
to the clavicle.
Separation of strap muscle
Midline is defined as a vertical incision made in fascia
separating the two sternohyoid muscles. Sternothyroid
muscles are separated from the thyroid gland.
Palpation of thyroid gland
The normal lobe is inspected and palpated for any undetected nodularity.
Ligation of vessels and dissection of thyroid
lobe
Identify and ligate the middle thyroid vein which drains
into the internal jugular vein. Inferior thyroid veins
which form a venous plexus in front of the trachea are
ligated and cut. Thyroidea ima artery may lie in front of
trachea; it is identified and ligated.
Branches of inferior thyroid artery are found close to
the thyroid. They are ligated medially preserving blood
supply to parathyroids. Recurrent laryngeal nerve may
pass anterior, posterior or through the branches of the
artery and care is taken to preserve it.
RLN is injured near the ligament of Berry when cautery
or artery forceps is used indiscriminately while cutting
the ligament of Berry to free the thyroid lobe.
Dissection of superior thyroid pedicle and
upper pole
Division of sternothyroid muscle near its upper part helps
to ligate superior thyroid artery and vein. They should be
ligated individually. External branch of superior laryngeal
nerve lies posteromedial to thyroid vessels and should be
identified and preserved. Traction inferiorly on the thyroid helps to save the nerve.
Preservation of parathyroids and their
blood supply
Branches of inferior thyroid artery are ligated distally as
close to the thyroid as possible to preserve parathyroid
blood supply. Also examine the thyroid specimen and if
parathyroids have been removed, they are identified, separated, sliced and implanted in the sternocleidomastoid
muscle. Before implantation, histological confirmation of
parathyroid tissue is made by frozen section.
Division of isthmus and separation of
thyroid lobe
Isthmus is separated from the trachea, doubly clamped
and divided. Cut surface of isthmus on contralateral side
is ligated with 3/0 chromic catgut by continuous interlocking suture for haemostasis.
Irrigation of wound
Wound is irrigated with saline or Betadine solution. Suction drainage is used to avoid haematoma formation.
Closure of wound
Anaesthetist performs Valsalva manoeuvre by intermittent positive pressure for any venous ooze and if none is
observed, wound is repaired. Strap muscles are approximated with 3/0 Vicryl. Platysma is also approximated
and subcutaneous sutures applied with 3/0 Vicryl and
then subcuticular sutures used for good cosmetic result.
Steri-Strips are then applied to further strengthen the incision lines.
Complications
1. Haematoma. It can be avoided by ligation of vessels,
at the time of surgery and performing Valsalva at the
end of operation to check for venous ooze. A haematoma can compress the airway and should be identified
early and evacuated.
2. Airway obstruction. Tracheotomy may be required.
Compression by haematoma, tracheomalacia and laryngeal oedema or myxoedematous cords also cause
obstruction to airway.
3. Injury to recurrent laryngeal nerve.
4. Injury to superior laryngeal nerve.
5. Wound infection.
6. Hypocalcaemia. Removal or devascularization of
parathyroid glands causes numbness and tingling of
lips, hands and feet. In such cases calcium level may
be less than 8.0 mg/dL. Critical period is 24-96 h after operation. Always check for serum calcium levels
postoperatively and compare with the preoperative
baseline value. It may require calcium and vitamin D
supplementation by oral or i.v. route depending on the
severity of hypocalcaemia.
7. Pneumothorax. Due to injury to pleura in the lower
neck.
8. Hypothyroidism. It is usually seen 4-6 weeks after
operation. This would require long-term thyroid replacement.
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Diseases of Oesophagus
S e c t i o n o u t l i n e
67 Anatomy and Physiology of Oesophagus, 385
68 Disorders of Oesophagus, 387
69 Dysphagia, 393
70 Foreign Bodies of Food Passage, 395
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Anatomy and Physiology
of Oesophagus
APPLIED ANATOMY
It is a fibromuscular tube, about 25 cm long in an adult.
It extends from the lower end of pharynx (C6) to the
cardiac end of stomach (T11) (Figure 67.1). It runs vertically but inclines to the left from its origin to thoracic
inlet and again from T7 to oesophageal opening in the
diaphragm. It shows three normal constrictions and it
is important to know their location at oesophagoscopy.
They are:
1. At pharyngo-oesophageal junction (C6)—15 cm from
the upper incisors.
2. At crossing of arch of aorta and left main bronchus
(T4)—25 cm from upper incisors.
3. Where it pierces the diaphragm (T10)—40 cm from upper incisors.
Foreign bodies in the oesophagus can be held up at
these constrictions.
The wall of oesophagus consists of four layers. From
within outwards, they are:
(a) Mucosa, which is lined by stratified squamous epithe-
lium.
(b) Submucosa, which connects mucosa to muscular
layer.
(c) Muscular layer, which has inner circular and outer
longitudinal fibres. Circular fibres at the lower end
are thickened to form a cardiac sphincter. The upper third of oesophagus has striated, the lower third
smooth, and the middle third both striated and
smooth muscle fibres (Figure 67.2).
(d) Fibrous layer, which forms loose covering of oesopha-
gus.
NERVE SUPPLY
Parasympathetic fibres come from vagus nerves (X) and
sympathetic fibres from the sympathetic trunk.
LYMPHATIC DRAINAGE
The cervical, thoracic and abdominal parts drain respectively into deep cervical, posterior mediastinal and gastric
nodes.
Figure 67.1. Anatomy of oesophagus and levels of normal constrictions from the upper incisors.
APPLIED PHYSIOLOGY
Manometric studies have shown two high pressure zones
in oesophagus and they form the physiological sphincters.
The upper oesophageal sphincter starts at the upper border of oesophagus and is about 3–5 cm in length and
functions during the act of swallowing.
The lower oesophageal sphincter is situated at lower portion of oesophagus. It is also 3–5 cm in length and functions to prevent oesophageal reflux.
Middle portion of oesophagus shows active peristalsis.
The waves are weaker in the upper part, becoming gradually stronger towards the lower portion.
PHYSIOLOGY OF SWALLOWING
The act of swallowing is divided into three phases:
1. oraL or BuccaL PhaSe. The food which is placed
in the mouth is chewed, lubricated with saliva, converted
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