MSC - F. Surgery Answers 2025

2.Pregnancy in 1st trimester (to avoid fetal thyrotoxicosis)

3.Children/adolescents with thyrotoxicosis

4.Complications of DTG: thyrotoxic heart, liver dysfunction, encephalopathy

5.Drug intolerance/toxicity (agranulocytosis, liver damage)

6.Inaccessibility to long-term follow-up or non-compliance

III. Preoperative Preparation

Objective: Achieve euthyroid state to prevent thyroid storm

Steps:

Mercazolil (methimazole) 20–60 mg/day

Propranolol or other β-blockers

Sedatives, anxiolytics

Glucocorticoids in severe cases

Plasmapheresis (optional, in resistant/severe thyrotoxicosis)

Special note: In diabetics, manage blood sugar alongside (insulin control)

In pregnancy, surgery is safest in 2nd trimester, but 1st trimester may be considered if life-threatening

IV. Surgical Technique

Standard: Subtotal (near-total) thyroidectomy

Performed under general anesthesia

Removes majority of thyroid tissue but spares small remnant to avoid lifelong hypothyroidism

Intraoperative frozen section may be used to rule out carcinoma

Post-op:

Continue antithyroid drugs + beta blockers for 2–3 days

Monitor for:

o Thyroid storm

o Recurrent laryngeal nerve injury

oHypocalcemia (parathyroid injury)

Discharge in 5–7 days if stable

Work ability resumes in 3–4 weeks

7.Autoimmune thyroiditis. Etiopathogenesis, clinical picture, diagnosis, treatment.

THYROIDITIS – OVERVIEW

Thyroiditis is inflammation of the thyroid gland. It may be:

Acute (Infective)

Subacute (Granulomatous/De Quervain’s)

Chronic (Autoimmune – e.g., Hashimoto’s, Riedel’s)

Hashimoto’s Thyroiditis (Chronic Lymphocytic / Autoimmune Thyroiditis)

Etiopathogenesis:

Most common thyroiditis, autoimmune in origin

Formation of antibodies against: o Thyroglobulin (TGHA)

o Thyroid peroxidase (TPO / antimicrosomal Ab)

Associated with other autoimmune conditions: RA, Addison’s, DM1,

pernicious anemia

Familial predisposition (HLA-DR5, DR3)

Pathology:

Diffuse symmetrical thyroid enlargement

Lymphocytic infiltration, Askanazy (Hurthle) cells

Gradual fibrosis, nodularity

Clinical Features:

Middle-aged females

Painless goiter, firm or rubbery

Symptoms of hypothyroidism (fatigue, weight gain, cold intolerance, bradycardia)

Early phase may have transient hyperthyroidism (“Hashitoxicosis”)

May co-exist with papillary thyroid carcinoma

Diagnosis:

High TSH, low T3/T4 (hypothyroid)

Positive anti-TPO and anti-Tg antibodies

FNAC shows lymphocytes, Hurthle cells

Ultrasound: hypoechoic, heterogeneous gland

Thyroid scan: low uptake

Treatment:

Euthyroid + small goiter: No treatment

Hypothyroid: Lifelong levothyroxine

Surgery Indications:

1.Large goiter with pressure symptoms

2.Cosmetic concerns

3.Suspicion of malignancy (nodular/rapid growth)

4.Retro-sternal extension

Surgical Approach:

Lobectomy + Isthmectomy or Subtotal thyroidectomy

Post-op: lifelong suppressive levothyroxine

Hashimoto’s = autoimmune, common, painless goiter + hypothyroid → thyroxine

8. Thyrotoxic crisis, damage of the recurrent nerve, bleeding.

Complication Time of Onset Key Sign Emergency Action

RLN injury Immediate Hoarseness, stridor Tracheostomy if bilateral

1. THYROTOXIC CRISIS (Thyroid Storm)

Definition:

A life-threatening complication from massive release of thyroid hormones, typically occurring within 1–2 days post-thyroidectomy in inadequately prepared hyperthyroid patients.

Incidence:

Occurs in 0.4–1.6% of patients

Mortality remains high if not promptly managed

Pathophysiology:

Sudden surge of T3/T4 into the bloodstream

Leads to adrenergic hyperactivity, cardiovascular collapse, multisystem failure

Adrenal decompensation may also occur

Precipitating Factors:

Surgery (esp. in thyrotoxic state)

Trauma, infection, DKA

Radioiodine therapy

Clinical Picture:

CNS: Agitation, delirium, psychosis, seizures, coma

Always prepare hyperthyroid patients pre-op until euthyroid using:

o Antithyroid drugs (ATDs)

o Iodine preparations

o Beta blockers

oSteroids

Delay surgery until clinically and biochemically euthyroid

BLEEDING (Post-Thyroidectomy Hemorrhage) Incidence:

Occurs in 3–4%

One of the most feared early post-op complications

Intraoperative Bleeding:

Due to:

oSlippage of ligature or clip

oInjury to superior/inferior thyroid arteries, thyroid veins

Management:

oDo not clamp blindly

oFirst apply pressure, then clear field, identify source, ligate securely

Postoperative Bleeding:

May be external or internal

Mediastinal hematoma is dangerous — can cause:

oVagal stimulation → bradycardia

o Airway compression → stridor, suffocation

o Reflex cardiac arrest

Clinical Signs:

Neck swelling, pressure sensation

Dyspnea, tachycardia

Tracheal deviation, stridor

Hypotension, pallor Management:

Emergency bedside wound opening if airway is compromised

Immediate return to OR for hemostasis

Ensure drain placement in high-risk cases

RECURRENT LARYNGEAL NERVE (RLN) INJURY

Incidence:

Most common nerve injury in thyroid surgery

Occurs in 0.1–12.1%

Unilateral → hoarseness

Bilateral → airway obstruction, stridor → emergency tracheostomy

Mechanism:

Nerve is vulnerable during ligation of inferior thyroid artery

Can be:

o Transected

o Stretched

o Thermally injured

o Entrapped in scar tissue or ligature

Clinical Features:

Unilateral injury:

o Hoarse voice

o Weak cough

o Aspiration

Bilateral injury:

o Aphonia

o Stridor, respiratory distress

o Need urgent airway management

Diagnosis:

Indirect laryngoscopy (preand post-op mandatory in high-risk patients)

Flexible nasopharyngolaryngoscopy

Treatment:

Most resolve spontaneously within 1–2 months

Medications: Proserin, B vitamins

Voice therapy, vocal cord exercises

Persistent bilateral palsy → cord medialization surgery, tracheostomy

Prevention:

Visual identification of RLN during surgery is gold standard

Avoid blind clamping or ligation

9.Postoperative hypothyroidism, postoperative hypoparathyroidism.

Muscle cramps, laryngospasm, seizures

Prolonged QT on ECG → risk of arrhythmias

Diagnosis:

Serum calcium ↓

Serum phosphate ↑

↓ or inappropriately normal PTH

Vitamin D level may be low, especially in winter

Treatment:

Conservative (Mainstay):

IV calcium chloride (10%) for acute tetany

Oral calcium supplements: calcium gluconate 6–10 g/day

Vitamin D (cholecalciferol or calcitriol):

o100,000–300,000 IU/day initially (adjust based on labs)

Magnesium: correct if low

Surgical/Experimental (Rare):

Calcium depot formation in severe cases

Parathyroid transplantation:

oHomotransplantation or autotransplantation into the sternocleidomastoid or forearm

Prevention:

Meticulous surgical technique to preserve parathyroids

Autotransplant parathyroid tissue if glands are removed or devascularized

Intraoperative PTH monitoring (if available)