Subtotal Thyroidectomy

Anaesthesia: General anaesthesia with endotracheal intubation.

Position of Patient: Patient supine, neck extended by placing a pillow in between the shoulder blades and head resting on a ring.

Antiseptic dressing and draping: Povidone iodine painting done from the level of the chin to the upper chest. Three towel draping done for the head and operated area isolated by further of draping sheets.

Incision: The approach is through a cervical collar incision made 2cm above the suprasternal notch extending from posterior border of one sternocleidomastoid to the posterior border of opposite sternocleidomastoid. The skin incision is marked by pressing with a silk thread on the skin (Garrott mark). The collar incision is made, the skin, superficial fascia and platysma are incised in the same line.

Raising the skin flaps: the upper skin flap with superficial fascia and the platysma are dissected and the upper flap is raised upto the upper border of the thyroid cartilage. The lower flap of skin, superficial fascia and the platysma are raised upto the suprasternal notch.

Incision of deep cervical fascia: the investing layer of the deep cervical fascia is incised in the midline. If the anterior jugular veins come on the way these may be ligated and divided.

Raising the fascial and strap muscles flap: the investing layer of the deep cervical fascia along with the strap muscles are lifted up from the thyroid gland to expose the lateral lobes of the gland covered by the pretracheal fascia. The pretracheal fascia is incised and the finger passed around the plane between the pretracheal facsia and the thyroid gland. If the enlarged lobes are large the strap muscles may be divided at a upper level as the nerves enter the strap muscles from below.

Division of the middle thyroid vein: the thyroid lobe is mobilised medially and the middle thyroid vein is identified passing from the middle of the lateral lobe to the internal jugular vein. The middle thyroid vein is dissected and divided in between ligature.

Division of superior thyroid vessels: the muscles are retracted upwards and laterally and the superior pole of lateral lobe of thyroid is exposed. The superior thyroid vessels are dissected close to the upper pole of the lobe. Three ligatures are passed around the superior thyroid vessels and the superior thyroid pedicle is divided keeping two ligatures on the proximal side. Care should be taken to avoid damage to external laryngeal nerve.

Division of inferior thyroid artery: the gland is retracted medially and the branches of the inferior thyroid artery is identified entering the lower pole of the thyroid lobe. At this stage the recurrent laryngeal nerve is identified running vertically up along the tracheooesophageal group. The individual branches of the inferior thyroid artery are identified and divided in between ligatures.

Dissection of inferior thyroid veins: the inferior thyroid veins emerges from the lower pole of the lateral lobe. These veins are dissected and divided in between ligatures. The dissection on the other side now divides the middle thyroid vein, superior thyroid vessels, inferior thyroid artery branches and the inferior thyroid veins in the same as above.

Dissection of thyroid isthmus: the thyroid isthmus is dissected free from the trachea by using a thyroid dissector.

Division of thyroid lobes: the assessment is made as to what amount of thyroid tissue is to be left behind. Several pairs of haemostatic forceps are applied along the proposed line of division of the thyroid lobe. These forceps help to control the bleeding. The thyroid lobe is then sectioned from the lateral to the medial side taking care not to injure the trachea. Once both the thyroid lobes are divided and the isthmus is dissected, the specimen is removed. The parathyroid glands are identified and preserved.

Haemostasis of the resected lobe: the cut margin of each lobe is overrun with continuous 3-0 atraumatic catgut sutures and the haemostatic forceps are removed.

Control of bleeding and placement of drain: all bleeding points are checked and bleeding controlled with ligatures or diathermy coagulation. Two suction drainage tube is kept one each at the sites of resected lobe.

Closure: the investing layer of the deep fascia is apposed with interrupted 3-0 polyglactin sutures. The platysma is apposed with with 3-0 polyglactin sutures. The skin is apposed with interrupted monofilament sutures or by subcuticular sutures.