2. Thyrotoxicosis
“clinical syndrome that results when
tissues are exposed to high levels of
circulating thyroid hormones.”
Hyperthyroidism Other causes like excessive
ingestion of thyroxine, release
of hormone in ovarian tumors
5. DIFFUSE TOXIC
GOITRE
Grave’s disease (S/S & diffuse vascular
goitre appears simultaneously)
Primary thyrotoxicosis
8 times more common in females
Hyperthyroidism more severe than secondary
Cardiac failure rare
6. FEATURES: FEMALE
Female with strong family predisposition
(50%)
Extra thyroidal manifestation
Middle or young age (30-50 yr)
Autoimmune disorder (evidence
:demonstration of TSH R auto – antibodies in
the circulation)
human Leukocyte antigen(HLA) and T-
lymphocyte may contribute
Enlargement of gland is diffuse.
•Pretibial myxoedema
• Proximal myopathy
• Acropachy
• Ophthalmoplegia
11. Site : Swelling in the lower part of the front of the neck.
Size : slight to moderate enlargement.
Shape : symmetrical.
Surface: smooth.
Skin overlying: is warm.
Special character : moves up & down with
deglutition.
Consistency : soft or firm
Edge: well defined.
Pulsations & thrills : are detected usually
at the upper poles
12. CNS signs
Insomnia
Tremors of tongue and outstretched
hands
Agitation
Exaggerated reflexes
13. Cutaneous Changes
Moist warm extremities
Profuse sweating & flushed face
Falling of hairs
Clubbing of fingers & toes
Soft and brittle nails
14. Pretibial myxoedema
B/L, non pitting edema, ± a/w
clubbing
aka thyrotoxic dermopathy
Seen in thyrotoxicosis pt. treated
with surgery or antithyroid drugs
Always a/w exophthalmos
Cause : deposition of
myxomatous tissue(GAG’s)
mainly in pretibial region
Skin – dry coarse and swelling
due to obliterated lymphatics by
mucin
15. CVS
More in elderly
PULSE
Rate : Sleeping pulse up to 100 – 120/ min
Character : water - hammer character
Rhythm: cardiac arrythmias are
superimposed on sinus tachycardia as
disease progresses.
16. Stages of development of
cardiac arrythmias in
thyrotoxicosis
Multiple extrasystoles
Paroxymal atrial tachycardia
Paroxysmal atrial fibrillation
Persistent atrial fibrillation
(non responsive to digoxin)
17. (V) Eye manifestations :
A. Exophthatmos ( > 50 % of cases ) :
TYPES :
a)Apparent ( mild = false) exophthalmos :
widening of the palpebral fissure due to spasm of
Muller's muscle.
18. b)True exophthalmos :
actual protrusion of the eyeballs.
It is an autoimmune disease
Infiltration of retro bulbar tissue with
inflammatory cells & fluids with
varying degree of spasm of upper
eyelid as LPS is partly innervated by
symapthetic fibres
Probably due to cross- reaction of thyroid antigen & eye (Schwartz )
C.T showing infiltration of
Retro bulbar spaces
True exophthalmos
With widdened palpebral
apperture and
clearly seen sclera
19.
20. Classification of eye changes in Graves’ disease
Class Definition
0 No signs or symptoms.
1 Only signs, no symptoms. (Signs limited to
upperlid retraction, stare, lid lag.)
2 Soft tissue involvement (s/s).
3 Proptosis
4 Extraocular muscle involvement(diplopia)
5 Corneal involvement.
6 Sight loss (optic nerve involvement).
Severe cases are marked by pappiloedema and corneal
ulceration referred to as malignant exophthalmos
21. Spasm and retraction usually disappears
when hyperthyroidism is controlled – B
adrenergic drugs
Sleeping propped up and lateral
tarsorrhaphy help protect the eye
Prednisolone – improvement has been
reported….intraorbital not preferred.
When the eye is in danger…orbital
decompression reqd
22. Toxic nodular goitre
Simple, nodular goitre
present for a long time
before the hyperthyroidism
Middle aged or elderly
Eye symptoms rare
Usually nodules are
inactive and interthyroid
tissue is overactive
If 1 or more nodules are
active – hyperthyroidism is
due to autonomous tissue
23. Toxic nodule
Solitary overactive nodule
Autonomous
Hypertrophy not due to
TSH-Rab
Normal surrounding
thyroid tissue is inactive
due to suppressed TSH
secretion bcoz of high ,
level of circulating
hormones
24.
25. TREATMENT
NON SPECIFIC – Rest and Sedation.
SPECIFIC – Medical intervention
Surgical intervention
Radioiodine
26. ANTI – THYROID DRUGS
Carbimazole, Propyluracil, Methimazole
B – adrenergic blockers – proranolol,
nadolol
Iodides – dec vascularity of the gland
only used as immediate preoperative
measure
Drugs help maintain euthyroid state for a
long time in hope of spontaneous
remission
Block
Cvs
effects
27. Regime
Start with 10mg carbimazole- 3 or 4 times a
day …. Latent interval – 2 weeks
When pt. becomes euthyroid, decrease the
dose to 5mg- 2 to 3 times a day for 6 to 24
months
Alternative regime- BLOCK AND
REPLACEMENT THERAPY
Inhibit all T3 T4 production with high dose and
then give maintainence dose of 0.1 – 0.15mg
of thyroxine daily
decreased risk of iatrogenic thyroid
insufficiency and less follow up required
28. Adv : no surgery and no use of
radioactive
Disadv: prolonged t/t and failure rate
about 50%.
aplastic anemia and agranulocytosis
Poor prognosis: large gland size,
severity of disease nad TSH-Rab levels
29. RADIO-IODINE
Destroys thyroid cells
Reduces mass of thyroid tissue below a
critical level
Slow response.. substantial
improvement expected in 8 – 12 wks.. If
not repeat dose
Higher dose – thyroid failure in 6mnths
Lower dose result in insufficiency
Due to sublethal damage to cells not
damaged by t/t
30. SURGERY
Indicated in- severe diffuse toxic goitre
- toxic nodular goitre with overactive
internodular tissue
-toxic nodule
Cures by reducing overactive mass
Subtotal thyroidectomy- long term followup
Total or near total thyroidectomy- immediate
thyroid failure with life long thyroxine
replacement… SIMPLIFIES FOLLOW UP
31. Adv: Goitre is removed, cure is rapid and
cure rate is high if surgery has been
adequate
Disadv: recurrence in 5% cases
risk of permanent hypothyroidism
nerve injury
young women – cosmetic issues
32. Structure
Each lobe
Pear shaped
2 *1*1 inches
Its apex lies at
Level of oblique line
Of thyroid cartilage
& base reach 5th.
Or 6th. Tracheal
ring
Isthmus lies on
2nd. ,3rd. ,4th ,
Tracheal rings
Pyramidal lobe
It is connected to hyoid bone
By fibrous band ( levator glandulae )
thyroid
2 capsules :
*true C.T. capsule around gland
*false outer capsule from
pretracheal fascia
Pretracheal fascia
33. 1- arterial :
Blood supply
• superior thyroid artery
• Branch from E.C.A..
– Inferior thyroid artery
– Branch from thyrocervical trunk
– Which is branch of 1st. Part of subclavian
Others
Thyroid artery from aorta ( may be absent )
Accessory tracheal & esophageal braches
34. 2- venous :
Superior thyroid vein
drain to I.J.V.
middle thyroid vein
drain to I.J.V.
inferior thyroid veins
drain to left innominate vein
The middle thyroid vein
Is the shortest soit is the
1st To be ligated
35. Superior laryngeal nerve
internal laryngeal nerve
Sensory to m.m of
Larynx above vocal cords
external laryngeal nerve
Motor to cricotyroid
Muscle
Injury causes voice weakness
It is closely related
To
Superior thyroid artery
Right R.L.N.
Turns around 1st. Part
Of subclavian artery
Left R.L.N.
Turns around arch of
aorta
Both supply all Intrinsic muscles
Of larynx except (cricothyroid )
& m.m below vocal cords
Injury causes vocal cord paralysis
36. Surgical anatomy
From superficial to deep:
Skin
Platysma (a muscle in superficial fascia
of neck)
Investing layer of deep cervical fascia
Pre-tracheal layer of deep cervical
fascia
Strap muscles of neck (thin flat muscles)
37. Preoperative preparation
Make patient euthyroid
CARBIMAZOLE regime (8-12wks)
Alternate: B adrenergic blocking drugs
abolish clinical manifest. of toxic state
propranolol(40mgTDS) or nadolol(160mg OD)
rapid response.. Operation can be arranged
within few days
continue therapy for 7 days postoperatively
40. Technique
GA with endotracheal intubation
Pt. is supine with table tilted at 15° at the
head end to reduce venous
engorgement (reverse trendelenburg)
Sand bag placed transversely under the
shoulder
Neck extended
Apply tension to skin, platysma and
strap msls for easy dissection.
41. Curved skin incision made midway
between notch of thyroid cartilage and
suprasternal notch
Flaps of skin, s/c, platysma raised
upwards to superior thyroid notch and
downwards to suprasternal notch
42. Exposing the gland
Investing fascia divided in the midline
Strap msls divided only if large area to be
exposed
Sternohyoid msl is mobilised off the thyroid
lobe taking care to stay close to msl and
outside capsule
Pretracheal fascia opened
Gland is exposed
43. Dealing with vessels
Arteries before veins (to prevent venous
engorgement)
Vessels clamped, divided and ligated
Superior thyroid artery ligated close to the
upper pole of the gland.
This is to prevent damage to external
laryngeal nerve.
44. Inferior thyroid artery is similarly dealt with
faraway from the lower pole of the gland
This is to safeguard recurrent laryngeal
nerve.
They are not routinely ligated to preserve
parathyroid function
Then superior, middle and inferior thyroid
veins are dealt with in a similar manner.
46. Parathyroid glands
Identified by careful inspection
If inadvertently or unavoidbly excised or
devasularised
Should be fragmented and auto-
transplanted immediately within
sternoclenomastoid muscle
47. Absolute hemostasis secured by ligation
of individual vessels and by suture of
thyroid remnants to tracheal fascia
Pretracheal msls and cervical fascia are
sutured and wound closed
48. Complications
Hemorrhage
Respiratory obstruction
Recurrent laryngeal nerve paralysis-Hoarseness
of voice
Hypocalcemic tetany (due to accidental removal
of parathyroid glands during total thyroidectomy)
Wound infection: This may manifest after 48
hours of surgery
Thyroid insufficiency
Thyrotoxic crisis
Hypertrophic / Keloid scar
Stitch granuloma
49. Post operative care
Transient hypocalcemia – oral Ca+2
maybe necessary….if severe then 10ml
IV Ca+2 gluconate 10% given
Screen parathyroid insufficiency –
serum Ca+2 measured 4-6wks after
operation
Recurrent thyrotoxicosis common –
lifelong follow up