Post Operative Thyroid Complications

Post-operative complications can occur after thyroid surgery. Following are the complications of thyroidectomy :

1.Tension Hematoma

• The occurrence of a tension hematoma in the neck after thyroid surgery is a post-operative  thyroidectomy complication, with a chance of occurrence of 0.1% to 1%. Causes of this include mainly slippage of ligature over the Superior Thyroid Artery, and at times bleeding can also occur from an unnamed muscular artery leading to the formation of a hematoma. Once a hematoma is formed in the neck, it will compress the trachea and lead to airway compromise, resulting in the patient having Respiratory Distress. Other consequences include ecchymosis over the wound or loosing of blood from the wound.

Management Of Tension Hematoma

• The first step in management of tension hematoma  is opening the sutures (all the sutures, including- skin, plastic, and facial sutures). After this, the hematoma is evacuated, and the pressure on the airway is released, resulting in respiratory distress loss. Re-exploring the patient and relegating the superior artery has to be done if it is the cause of the bleeding of hematoma.

2. LARYNGEAL EDEMA

• Laryngeal Edema is also one of the postoperative thyroidectomy complication. This is caused due to huge goiters, which cause trauma to the larynx during intubation at the surgery that can lead to laryngeal edema.  In the postoperative period, larynx edema can be the reason for respiratory distress.

3. Tracheomalacia

Cause

• It occurs when a huge goiter is sitting in the trachea for a long period. This causes softening or weakening of the tracheal cartilages. So later when the goiter is removed in the surgery, the trachea collapses leading to respiratory distress. 

Management

• Before surgery, suspect that the patient has tracheomalacia and we anticipate that respiratory distress can occur due to tracheomalacia. For this, the patient is intubated electively for 1 or 2 days. The endotracheal tube is kept in situ and the patient is electively ventilated for 1 to 2 days so, after which there is fibrosis, and the trachea does not collapse.

4. Nerve Injuries

Nerve injuries is also the post-operative thyroidectomy complication. The two most commonly involved nerves that can get injured during the surgery are- 

 A. External Branch of Superior Laryngeal Nerve (EBSLN) and

 B. Recurrent Laryngeal Nerve (RLN).

Out of nerves that can get an injury in surgery, EBSLN is the most commonly injured nerve with about 20-22% occurrence rate whereas, RLN has only a 4% to 10% temporary damage occurrence rate and 0.5% to 2% permanent damage occurrence rate but have more severe manifestations(symptoms) that can also be life-threatening.

A. External Branch Of Uperior Laryngeal Nerve Injury

• If the External Branch of the Superior Laryngeal Nerve is injured following manifestations might occur-The patient will have a loss of pitch in voice. The patient cannot strike high notes. Voice fatigue after a long speech.

B. Recurrent Laryngeal Nerve Injury- 

Potential sites where RLN injury can occur include- (3 sites):

• At the level of ligament of the berry. The second site includes where RLN is closely related to the inferior thyroid artery or its branches. In the thoracic inlet at the tracheoesophageal groove. ligament of Berry is the most common site of RLN injury during thyroid surgery. Once RLN is injured, possible manifestation has mixed pathology due to the mixed distributions of RLN. RLN has sensory, mortar, and autonomic distributions. It also supplies all intrinsic muscles of the larynx except the tracheothyroid, along with sensory supply to the vocal cords. This results in mixed pathology when RLN injury occurs, but the most common manifestation is the injury of paralysis of an affected vocal cord at the affected site.
• RLN injury can be unilateral or bilateral and manifestations depend upon the position of chords where it has got paralyzed (median, paramedian, or abducted).  

Unilateral RLN Injury

• In unilateral injury, if the chord is paralyzed at midline/median or paramedian position then the opposite chords will try to cross the median, and approximation of the paralyzed chord by the functional chord occurs. This results in the patient being able to speak in a nearly normal voice, some with slight hoarsening or weakening. If the chord is paralyzed in an abducted position, an opposite chord cannot approximate because of which the patient will have severely impaired voice and poor cough reflex increasing chances of aspirations.

Bilateral RLN Injury

• In bilateral injury of RLN, when both chords are paralyzed in the median position or a paramedian position, the patient suffers a loss of voice and severe airway obstructions. This situation can be life-threatening and needs the urgent establishment of an airway. If the chords are paralyzed in an abducted position, airway compromise is not severe, and air can pass through but the patient suffers ineffective cough reflexes and higher chances of aspirations and respiratory tract infections.

5. Hypoparathyroidism

• Causes of hypoparathyroidism include devascularization of the parathyroid gland while surgery or accidental removal of the parathyroid gland completely. Hypoparathyroidism can be temporary or permanent. Hypoparathyroidism is defined as temporary when it occurs for less than 6 months after surgery. Permanent hypoparathyroidism is when it occurs for more than 6 months.

Time Of Presentation

• Hypoparathyroidism can manifest itself as fast as 24 hours of surgery, but most commonly 2 to 5 days after surgery. Hypoparathyroidism is the most common complication of thyroid surgery and shows symptoms in the form of hypocalcemia, with the earliest symptoms of hypocalcemia being circumoral tingling. Two types of clinical signs include- 
  • Trousseau signs- If we inflate blood pressure and cough above systolic blood pressure for more than 3 minutes, there can be carpopedal spasms. 
  • Chvostek’s signs- If we tap an area of the facial nerve, it causes a facial spasm.

Also Read: Thyroid Gland - Anatomy, Embryology, Developmental abnormalities, Symptoms, Investigation

Treatment

• Treatment of hypoparathyroidism depends upon the presence or absence of symptoms and their severity, Total Serum Calcium, and the level of serum parathormone.  Patients with more serve symptoms, where the calcium parathormone level is low and the calcium level is less than 8mg/dL, are treated with IV calcium gluconate and oral vitamin D and Ca as well. Patients with mild symptoms are mild and calcium level more than 8mg/dL, we can manage patients with oral calcium and vitamin D only.

In case of accidental removal of the parathyroid gland, it can be auto transplanted. The most appropriate location for auto transplantation is the sternocleidomastoid muscle.

6. Thyroid Storm/ Thyroid Crisis

• Thyroid storm is a complication that can occur in the post as well as intraoperative period as well. Thyroid storm is more common during surgery than post-surgery and can also possibly occur before or pre-operative to the surgery.

Causes 

• Inadequate preparation of patients before surgery being the most common reason. Other reasons include rough handling during surgery, infections trauma, radioactive Iodine, and by drugs like amiodarone.

Manifestations

• Thyroid storm manifests itself most commonly as Arrhythmias. Other manifestations include hyperpyrexia, confusion, agitation, vomiting, dehydration, and adrenergic overstimulation ultimately can lead to coma.

Management 

• Management includes- Cooling patients with ice packs, Treating with aggressive IV fluids, Antithyroid drugs (PTU, Carbimazole), Oxygen, Beta-blockers (Propranol- IV or oral). If needed, Iodine (Sodium donate IV/ lugol’s iodine 10 drops 8 hourly oral), IV steroids, Digoxin. If the patient does not respond, Plasmapheresis or Plasma Exchange has opted as a last resort.

7. Hypothyroidism

• Hypothyroidism is a common postoperative complication that occurs especially when total thyroidectomy and sometimes even after sub-thyroidectomy over a long period of over about 30 years) leads to hypothyroidism.

Also read: 5 Pro Tips To Unleash Peak Performance In NEET-SS Exam

Advancement in Thyroid Surgery

Advancements in thyroid surgeries have led to safeguarding the structure. These advancements include- 

1. Intra Operative Nerve Monitoring - (safeguards RLN)  This advancement can be of 2 types, Continuous and Intermediate.
   • Continuous intraoperative nerve monitoring includes the use of electrodes placed in the endotracheal tube, whereas Intermittent intraoperative nerve monitoring includes periodic stimulation.
2. Novel Technology For Parathyroidal Gland Identification- To avoid accidental removal of parathyroid gland involves- Near-Infrared Autofluorescence and Indocyanine Fluorescence angiography using indocyanine green dye.
3. Minimal Invasive Video Assisted Thyroid Surgery (MIVAT) – MIVAT can be used in case of benign thyroid swellings when less than 3 cm and papillary Ca-T1. MIVAT can be done including approaches most commonly from Trans axillary, other approaches include Anterior chest, Trans oral from nipple-areola complex, and retro auricular approaches.

MIVAT is avoided in cases of prior history of neck surgeries, lymph node metastases, large swellings, and thyroiditis.

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