short description of thyroidectomy

1. Thyroidectomy--Subtotal, total and hemi thyroidectomy--
JISHNU.K.R
FINAL MBBS

2. Preoperative preparation:
 Aims to make the patient biochemically
euthyroid at operation.
 Carbimazole 30- 40mg per day is DOC.
 ‘Block and replace’ regime.
 Alternative method by using β adrenergic
blockers- propranalol 40mg TD or Nadolol
160mg OD

3.  It is important to continue the drug β
blockers for 7 days postoperatively.
 Less effective alternative is Iodine which
produces a transient remission and may
reduce vascularity .

4. Preoperative investigations:
 Thyroid function tests
 Laryngoscopy
 Thyroid antibodies
 Serum Ca estimation
 Isotope scan- before preoperative
prepartion is necessary in patient with toxic
nodular goitre if total thyroidectomy is not
planned.

5.  Extent of the resection depends on:
◦ The size of the gland
◦ The age of the patient
◦ Experience of the surgeon
◦ The need to minimise the risk of recurrent
toxicity,
◦ And, wish to avoid postoperative thyroid
replacement.

6. Types:
 Sub-total: about 8gms , or a tissue, size of
pulp of finger is retained on lower pole on
both sides and rest is removed. Commonly
done in toxic thyroid, MNG.
 Total: entire gland is removed. Done in
malignancy.

7.  Near-total: both lobes except the lower
pole which is very close to recurrent
laryngeal nerve and parathyroid is removed.
Here <2gm of tissue is left behind.
 Hemi: along with removal of one lobe,
entire isthmus is removed. Done in benign
disease of only one lobe, thyroid cyst,
solitary nodule.

8. Technique:
 GA with endotracheal intubation and
muscle relaxant.
 Patient in supine position, table tilted up 15
degree at the head end.
 Sand bag is placed under the shoulders and
neck is extended.
 Incision: a gently curved skin-crease
incision is made midway between the notch
of the thyroid cartilage and the suprasternal
notch.

9.  The flaps are raised and fixed and the deep
cervical fascia is divided in the midline.
 Middle thyroid veins ligated and divided.
 Ligate the branches of superior thyroid A
individually.
 Inferior thyroid A ??

10.  The recurrent laryngeal nerve is identified
as it is intimately related to the terminal
branches of the inferior thyroid A.
 Parathyroid glands are identified.
 The thymus is detached by serially dividing
the inferior thyroid veins.

12.  In subtotal: the isthmus is transected and the
lobe resected obliquely from the medial and lateral
aspect to produce a V shaped surface.
 Care is required to avoid devascularisation of
parathyroid and injury to recurrent laryngeal
nerve.
 If parathyroid is unavoidably excised or
devascularised, it should be fragmented and auto
transplanted immediately within the SCM muscle.

14.  Total thyroidectomy: avoids transection
of thyroid tissue by complete excision of the
gland including the pyramidal lobe with
preservation insitu or auto transplantation
of as many parathyroids as can be
identified.
 The pretracheal muscles and cervical fascia
are sutured and wound closed.

15. New technologies:
 Achievement of haemostasis: ultrasonic
shears and enhanced bipolar diathermy.
 RLN identification: electrical stimulation.

16. Complications:
1. Haemorrhage
2. Respiratory obstruction
3. RLN palsy and voice change
4. Thyroid insufficiency
5. Parathyroid insufficiency
6. Thyrotoxic crisis
7. Wound infection
8. Hypertrophic scar
9. Stitch granuloma.

17. Haemorrhage
 Tension haematoma deep to cervical fascia
occurs due to reactionary h’age.
 Requires urgent decompression by opening
the layers of the wound.
 Sub cutaneous haematoma require
evacuation in the following 48hrs

19. Respiratory obstruction:
 Mostly due to laryngeal oedema.
 Other causes: tracheomalacia and trauma
perioperatively.
 Try releasing tension haematoma and if it
still persists an intubation should be done
and kept for several days.
 Give steroids to reduce oedema.
 If necessary, tracheostomy.

20. RLN palsy and voice change:
 May be U/L or B/L.
 Injury to ext. branch of superior LN is more
common and leads to loss of tension in the
vocal cord with diminished power and
range in the voice.
 Can be detected by postoperative
laryngoscopy.

21. Thyroid insufficiency:
 Occurs within two years following subtotal
thyroidectomy.
 This results from a change in the
autoimmune response from stimulation to
destruction of thyroid cells.

22. Parathyroid insufficiency:
This is due to removal of parathyroid glands
or infarction.
Thyrotoxic crisis:
Acute exacerbation of hyperthyroidism due to
inadequate preoperative preparation. Administration
of iv fluids, cooling the patient with ice packs, O2 ,
diuretics, digoxin, sedation and iv hydrocortisone.
Specific Rx: Carbimazole 10-20mg 6th hrly; lugol’s
iodine 10 drops 8th hrly; propranalol 1-2mg iv.

23.  Woundinfection: cellulitis- antibiotics; abscess-
drained.
 Hypertrophicor keloidscar: intradermal injection of
corticosteroid once monthly.
 Stitch granuloma: due to non absorbable suture
material.

24. Postoperative care:
 About 25% develop transient hypocalcemia
and oral Ca 1gm TD.
 For severe hypocalcemia: 10ml iv Ca
gluconate 10% and alfacalcidol 1-2µgm
daily.
 Lifelong follow up to detect recurrent
thyrotoxicosis and thyroid failure.