thyroidectomy-surgical seminare, prepared by Dr. Siddharth JINDAL, third year resident in dept. of general surgery at P.D.U. Government Medical College and Civil Hospital, Rajkot, Gujarat.
2. ”
“The most important thing about
thyroidectomy is the meticulous
dissection needed for Preserving
The Two Nerves And Bilateral
Parathyroid Glands
Thus, rendition of a symphony
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3. CURTAIN RAISER
1. Surgical Anatomy What We Already Know.
2. Triangles In Thyroid Surgery Geometrical Nexus In The Neck!
3. Appreciation of the Historical Contributions
4. Types of Thyroidectomy
5. Patient Preparation for The Surgery
6. Operative Procedure
7. Complications
8. Recent Advances
9. Summary
10. Thyroid trivia
11. Q&A
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4. SURGICAL ANATOMY
OVERVIEW OF THE GLAND
VASCULAR SUPPLY
INNERVATION & LYMPHATIC SUPPLY
RELATIONS
MUSCLES TO KNOW
MISC. FACTS
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13. THYROID’S
INTIMACY
WITH VAGUS
1. Superior thyroid artery is
accompanied by ELN
2. RLN runs in the
tracheo-esophageal groove
near the posteromedial surface
close to the thyroid gland;
• nerve lies b/w the branches of
inferior thyroid artery ~ 50% on
right side;
• on left side nerve lies posterior to
the Inferior thyroid artery in ~50%
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16. MUSCLES
Anterior aspect of neck
Supra-hyoid muscles
1. Stylohyoid
2. Geniohyoid
3. Mylohyoid
Infrahyoid - STRAP MUSCLES
1. Sternohyoid- in front
2. Omohyoid- in front
3. Sternothyroid- deep to above m/s
4. Thyrohyoid- deep to above m/s
Mnemonic: TOSS
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18. TUBERCLE OF ZUCKERKANDL [Misc.]
TZ is postero-lateral projection from the thyroid lobe resulting at a point where lateral and the
medial components fuse.
Applied importance:
1. Grade 3 TZ: significant pressure symptoms, persistent after subtotal thyroidectomy
2. Intimately assoc. with RLN & Superior parathyroid. Enlargement occurs lateral to RLN—
The nerve appears to pass into a cleft medial to the enlarged tubercle.
3. Elevation of TZ: safe dissection; RLN passes medially through tunnel
4. The widened pre-vertebral space on X-ray of neck: (?) enlarged TZ [grade 2/3]
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19. Grading of TZ
Grade I <0.5cm
Grade II 0.5-1.0 cm
Grade III >1cm
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22. BEAHR’S TRIANGLE
[RIDDLE’S]
USED TO IDENTIFY RLN CLOSE TO TEG
BOUNDARIES:
RLN [LOWER ARM]
INFERIOR THYROID ARTERY [SUPERIOR]
COMMON CAROTID ARTERY [BASE]
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23. LORE’S
TRIANGLE
IDENTIFICATION OF RLN INFERIORLY
BOUNDARIES:
MEDIAL: Medial border is formed by
trachea and esophagus
LATERAL: CCA
SUPERIOR: Surface of inferior pole of
thyroid gland
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25. RLN TRIANGLE
Inverted Triangle--
Apex: inferiorly: thoracic inlet
Medially: trachea
Laterally: medial edge of retracted
strap muscle
Superiorly: lower edge of inferior pole
of the gland
RLN exits as single trunk here
@ thoracic inlet
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26. TRIANGLE OF
CONCERN
COMMONEST SITE FOR BLEEDING IN
THYROIDECTOMY
Boundaries
Medial: trachea
Lateral: RLN
Base: thyrothymic ligament and loose fat
above sternum/
SMALL BRACNHES OF INFERIOR THYROID
ARTERY
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31. Down the memory lane…
1912: KOCHER first thyroid surgery
Billroth, Kocher, Joll , Lahey and Galen: importance of laryngeal nerve preservation in thyroid
surgeries.
Illustration & description of nerves: Leonardo Di Vinci and Vesalius
20th century: Russian: Alexander Borbov: routine visual identification of nerves
George Crile: region of RLN , “no man’s land”
1935: Amelia Galli-Curci, famous opera singer [soprano], underwent a disastrous thyroid surgery,
EBSLN damaged.
Indian contribution: Sushruta [6th century B.C.] First to describe injury to neck at angle of jaw
voice hoarseness [? blood vessels]
Rufus and Ephesus: hoarseness was due to nerve injury and not vascular injury
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41. WORKUP
1. DL/IDL: VC check
2. CECT/MRI/intra-luminal imaging: potentially more advanced and regional disease
3. XRC [PA]- Retrosternal goiter
4. Decrease vascularity and risk of thyroid storm: anti-thyroid medications, beta blockers, lugol’s iodine [SSKI]
5. Rx of Beta-Blockers: continued for 7-10 days post-op because of longer t ½ of T4
6. MTC: r/o Phaeochromocytoma and MEN syndromes
7. Serum Calcium & PTH assay
8. In c/o thyroidectomy for solitary thyroid nodule, workup
TFT- serum TSH [higher TSH is an independent risk factor for malignancy]
USG, Radionuclide scintigraphy
FNAC
Thyroid suppression therapy 30-09-2021
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42. 1. Adequately consented
2. North facing endotracheal tube, so that it doesn’t interfere with surgical field.
3. LA – to help hemostasis while raising flaps; aids in post-op analgesia.
4. Neuromonitoring
5. Surgical aids: loops, microscope, fine bipolar forceps, ligaclips
6. Mild hypotensive anesthesia should be used but reversed before the procedure is
completed.
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56. METICULOUS DISSECTION
Preserving Superior
Laryngeal nerve
Each branch of superior thyroid
vessels is isolated, ligated and
divided individually at the point
where it enters the thyroid gland.
Preserving and
identifying RLN
Knowing the course and
anatomic variants
Parathyroid
preservation
• Familiarity with anatomic
location
• Inferior: fat surrounding inferior
thyroid vessels
• Superior: poster lateral to RLN
• Preserve posterior thyroid
capsule
• Divide inferior thyroid, distal to
origin of blood supply to
parathyroid.
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57. POSITIONING
• Supine
• Semi-fowler’s position
• Neck extended
Shoulder roll
• Head supported by donut pillow
Allows anterior mobilization of the
visceral compartment.
r/o cervical spine ds.
Pre-op antibiotics- no need
Draping- double towel
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58. INCISION
KOCHER COLLAR INCISION
1. 1 fingerbreadth below cricoid anterior arch.
2. 2 fingerbreadths above suprasternal notch.
3. Incision in or parallel to normal crease: good post-op
cosmesis.
4. Stretching it to a silk ligature over the planned incision site
facilitates marking a balanced skin incision.
5. Incision should be in midline.
6. Incision too low, in women with larger breasts, descend
into sternum, high chance of keloid formation.
7. Length : adequate for mobilisation
8. Larger incisions: larger lesions/short or heavy necks/low
set larynx
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60. SURGICAL OUTLINE
o Ventral to Dorsal Approach
o Inferior Pole Dissection
o Berry’s Ligament Dissection
o Superior Pole Dissection
o Isthmusectomy
o Contralateral Surgery
o Closure
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63. STRAP MUSCLES & MIDLINE AIRWAY
1. Palpate thyroid cartilage prominence midline
2. Make an incision through cervical fascia in the midline and extend the incision to
expose the full length of the strap muscles. [sternothyroid & sternohyoid]
3. Elevate sternohyoid muscle in midline.
4. Elevate sternothyroid muscle and dissect the thyroid capsule away from it on both sides.
5. This permits adequate digital exploration of entire thyroid gland.
6. Most cases, retract strap m/s: laterally, retract thyroid lobe in opp. direction
7. If gland is unusually large: transect sternothyroid muscle [laryngeal part] in upper third
[Why?]
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65. STAP MUSCLES- DIVISION- YES OR NO?
If lateral retraction of the strap m/s doesn’t provide adequate exposure,
they should be divided without hesitation.
Maneuver can helpful not only when thyroid lesion is large but also, when
• Thyroid and larynx are low set
• Barrel chested males in c/o COPD
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67. True thyroid capsule has large capsular vessels, which cause significant
bleeding, if handled aggressively.
Pyramidal lobe: inferior most portion of the embryological remnant of the
thyroglossal duct tract. 30-40%
Look for Delphian lymph nodes in this area.
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69. 30-09-2021
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Loose connective tissue after division/retraction of strap
muscles
Its between true capsule of thyroid and straps
It’s the false thyroid capsule/peri-thyroidal sheath
Represents: pre-tracheal portion of the middle or visceral
layer of the deep cervical fascia
Cauterize occasional vessels which are undersurface of
the straps, arising from the true capsule after individual
identification.
True thyroid capsule bluntly dissected digitally
71. Lateral thyroid region is opened up by division of middle thyroid vein
Ligate Middle Thyroid Vein, if +
Retract laterally:
Strap muscles
Carotid sheath to some extent
SCM
Medial retraction of the thyroid gland and Laryngotracheal complex
exposes the parathyroids and RLN
Tip: Gauze and digital retraction works best, avoid instruments that
penetrate the thyroid such as the Lahey’s clamp
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73. INFERIOR POLE DISSECTION
Dissection of inferior pole related veins
Inferior parathyroid identified
Inferior parathyroid swept away and preserved with dissection being medial to upper cranial
aspect of the inferior parathyroid gland
Ideally: inferior parathyroid marked with a small surgical clip, reflected inferiorly & laterally
before one searches for the RLN.
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77. RLN & Inferior Thyroid artery
• Several approaches
• Triangles [mentioned earlier]
• Thoracic inlet in the RLN Triangle: advantage single nerve trunk [prior to branching]
• Most extra-laryngeal nerves are superior, once its crossed the inferior thyroid artery.
• If found at inferior location, avoid tracing the entire course
• Identify inferior thyroid artery
• Inferior thyroid artery and RLN- intimate foreplay, relations described earlier
• Its typically deep to the artery
• Relationship varies from side to side
• Identification of ITA not only helps in identification of the RLN but also the parathyroid.
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82. DISSECTION AT LIG. OF BERRY
Challenging
Indiscriminate cautery and clamping- neural injury
RLN should be dissected and visualized up until it disappears from the surgical field by
entering the inferior most fibers of the inferior constrictor muscle lateral to the cricothyroid
m/s at the lower edge of the lateral cricoid cartilage k/a laryngeal entry point
RLN should be in constant view during retraction.
Lig. of Berry – if post component + to RLN, judicious thyroid lobe retraction conveyed to the
nerve upward bowing of the nerve; transient neuropraxia
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84. SUPERIOR POLE & SLN
1. Why now? Greater lobe mobilization
2. Superior pole vessels are dissected, downwards mobilization using mayo
clamp.
3. Superior pole parenchyma facilitating downward retraction.
4. Final segment of RLN identified with ease
5. Better accessibility: sternothyroid transection, and medial retraction of the
complex
6. Laryngeal head of the sternothyroid muscle as It inserts on the oblique line
of thyroid cartilage of the larynx, robust indicator of EBSLN, as it runs down
just posterior on the inferior constrictor muscle on the lateral edge.
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87. • Superior pole vessels should
be taken individually to
optimize their control
Avoids risk to EBSLN
• Posterior branches of superior
thyroid artery may contribute
to the blood supply of the
superior parathyroid , should
be reflected posteriorly &
maintained
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91. ISTHMUS
Can be divided easily
Any point of thyroidectomy
Generally, divided at the junction with the contralateral lobe opposite to tumor
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92. BEFORE CLOSURE
1. If appropriate, lobectomy specimen frozen section.
2. Examine neck for nodes [jugular III/IV]
3. Inspect for parathyroid glands
4. Lee found that 11% of 414 thyroidectomy specimens had parathyroid
5. Any presumptive parathyroid should be biopsied for confirmation and then autotransplanted.
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93. FINAL CLOSURE
1. Assess for hemostasis on thyroid bed, strap m/s and airway
2. Ask anesthetist to give cycles of PPV, assess for bleeders, if any
3. Proper wash
4. Drains are infrequently needed, individual choice
5. With large dead space, extensive dissection and strap muscle tansection; drainage may be
appropriate, 15 Fr JP drain.
6. 3-0 absorbable suture, re-approximate strap muscles
7. Close platysma with absorbable sutures
8. Skin: subcuticular stitches
9. Remove dressings after 2 weeks.
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94. THYROID BED UPTAKE AFTER TOTAL
LOBECTOMY
LIG OF BERRY
Most common
Close relationship with RLN
PYRAMIDAL LOBE
Must be sought and dissected
superiorly to the level of notch in
the thyroid cartilage
SUP. POLE
More tapered
More bullous
Clamps should be placed high to
encompass
Don’t mass ligate the superior pole
Ligate individually.
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95. POST-OP CARE
Tracheomalacia- on extubation
1. Position: 45 degrees head up for first hours post-op
2. Steroid therapy [i/v] in first 24 hours [analgesia + reduces trans neuropraxia]
3. Antibiotic prophylaxis + analgesia
4. Early mobilization
5. Resume oral intake: complete consciousness, within 4 hours
6. Drain removal <20ml/24h or <10ml/8h
7. Calcium management
8. Post-op VC check
9. Venous thromboembolism prophylaxis: within 24h till discharge
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97. HAEMORRHAGE [1%]
1. Slippage of ligatures
2. Ppt by vigorous coughing or retching in post op period
3. S/S: tachycardia, breathlessness, hypotension
4. Progressive tension hematoma under strap muscles
5. Bedside removal of skin & deeper sutures
6. Later shift to OT and assess
7. BT (sos)
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100. HYPOPARATHYROIDISM
• Clinical assessment for HYPOCALCEMIA [clinical signs]
• Asymptomatic: no Rx
• Symptomatic hypocalcemia: Treat with P/O- I/V [Calcium prepn]
• Need for supplementation > 6 months: permanent hypoparathyroidism
• After 2 months: try weaning off from oral calcium and re-assess.
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101. THYROID STORM/CRISIS
Unusual
In thyrotoxic patients, inadequately prepared
Happens due to stress or operations
Mortality ~ 50%
Tachycardia, hyperpyrexia, cardiac collapse, altered mental status, hypotension,
severe dehydration, tremors and nausea
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103. HUNGRY BONE SYNDROME
1. Pts with pre-op hyperthyroidism
2. Increased bone breakdown in their hyperthyroid state
3. After surgery bone breakdown over, “hungry” for calcium
4. Remove calcium from plasma rapidly, Sr. ALP rises
5. HypoCa, HypoPO4, HypoMg, HyperK ECG changes +
6. Hyperkalemia: urgent treatment
7. Magnesium infusion needed.
8. Rx: Vit D3 + Calcium supplentation for 6 months
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104. EBSLN INJURY
Mostly unnoticed, more common [as compared to RLN palsy]
Unless professionals [singers, teachers]
Diagnose with fiber-optic laryngoscope
Bowing of VC on paretic side
Videostroboscopy : Assymetric mucosal traveling wave
laryngeal EMG: denervation to cricothyroid muscle
Rx : speech therapy
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105. NERVE INJURIES IN THYROID SURGERY
I. EBSLN injury- not life threatening. Will just lead to
hoarseness
• Inability to sing a high pitch: cricothyroid
II. U/L RLN injury: hoarseness
I. B/L RLN injury- airway obstruction, stridor [emergency]
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106. OTHER COMPLICATIONS
1. Hypothyroidism: supplement levothyroxine
2. Infection antibiotics
3. Recurrent thyrotoxicosis: more common with subtotal thyroidectomy
4. Seroma formation
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110. INTRA-OPERATIVE NEUROMONITORING
IONM systems for RLN/X: electrical stimulation– EMG signal at VC
Detected by electrodes embedded in ET tube
All IONM: Intermittent direct stimulation, before & after thyroid surgery
Continous stimulation of vagus monitor, during dissection
Some developed countries, mandatory
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112. FLUROSCENT IMAGING AIDS FOR
PARATHYROID IDENTIFICATION
1. Critical for prevention of hypoparathyroidism
2. Detects fluorescence from parathyroid glands
3. Parathyroid tissue auto-fluoroscence in the near infra-red spectrum [285nm]
4. Detection: spectroscopy
5. Adv: non-invasive & avoidance of exogenously administered fluorophore
6. Disadv: limited penetration [few mm], software expertise, visible spectrum light to be turned off
7. Exogenous fluorophore: indocyanine green [i/v]
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115. BIBILIOGRAPHY
1. Surgery of the Thyroid and Parathyroid glands- 2nd edition: Gregory W. Randolph
2. Atlas of thyroid surgery: principles, practice and clinical cases: Ernest
Gemsenjaeger
3. Chassin’s operative stategy in General Surgery: An expositive atlas: 4th edition
4. SRB’s surgical operations: text and atlas
5. Kirk’s general surgical operations: sixth edition
6. Scott-Brown’s otorhinolaryngology head & neck surgery- volume I, 8TH edition
7. Sabiston textbook of surgery: 21st edition.
8. Schwart’z principles of surgery: 11th edition
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117. In what location,
relative to inferior
thyroid artery, is the RLN
found?
1. Medial or posterior to the ITA
2. Lateral or anterior to the ITA
3. Passing b/w the branches of ITA
4. All of the above
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119. An asymptomatic child with
normal physical
examination is found to
harbor a mutation in codon
918 of the RET tyrosine
kinase receptor,
compatible with MEN 2B.
USG of neck is
unremarkable & Sr.
Calcitonin levels are
normal. What course is
indicated ?
1. Repeat examination and
ultrasound yearly
2. Total thyroidectomy
3. Planned thyroidectomy in 3-5
years
4. Total thyroidectomy with bilateral
neck dissection
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120. 48/F with thyrotoxicos is
referred to the clinic,
she was poorly
controlled on
carbimazole and has
received orbital
radiotherapy for severe
proptosis. This has
improved matters but
she has relapsed on
stopping her
carbimazole.
1. Tru cut biopsy
2. Radioactive iodine
3. Thyroid lobectomy
4. Total thyroidectomy
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121. 55/M is in the HDU for
many months after
open aortic surgery.
He is maintained on
TPN. Clinically he is
euthyroid, but his TFT
reveal low TSH & low
T4. Diagnosis?
1. Sick euthyroid syndrome
2. Hypothyroidism
3. Hashimotos thyroiditis
4. Poor compliance with
thyroid metabolism
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122. Last dose of
carbimazole when
given in pre-op
preparation in a
thyrotoxicosis patient
for thyroid surgery is
given at?
1. 7 days prior to surgery
2. 5 days prior to surgery
3. 3 days prior to surgery
4. Evening before surgery
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