Surgery on the thyroid gland

Indications and scope of surgery

Surgical treatment is indicated for patients with nodular or diffuse thyrotoxic goiter, as well as for malignant tumors (cancer). Depending on the severity and type of disease, different volumes of resection are used:

• Conservative resection. Performed for benign single nodules. During the surgery, the surgeon removes the nodule itself along with the immediately adjacent atrophied tissue of the organ.
• Subtotal resection. Used for thyrotoxic parenchymatous goiters that do not respond to conservative treatment. During the procedure, the major part of the gland is removed. Small areas of the lateral lobes—approximately 2–4 g each—are necessarily left on either side of the trachea. The main purpose of preserving this tissue is to securely cover the recurrent laryngeal nerve (n. laryngeus recurrens) and protect the parathyroid glands from injury.

Classification of removal methods

Globally, methods of strumectomy are divided into two groups depending on their relation to the fascial capsule:

1. Extracapsular method. The gland is removed en bloc along with its outer fascial capsule. The method is indicated for malignant lesions of the organ. The main disadvantage is the high probability of accidental damage to the parathyroid glands and the recurrent laryngeal nerve, as the work is performed within the "danger zone".
2. Subcapsular method (according to O. V. Nikolaev). Involves subtotal subcapsular strumectomy. The gland is isolated, while the outer fascial capsule is preserved and subsequently sutured over the stumps. The method is widespread in the Russian Federation and has proven its effectiveness by radically reducing mortality.

According to the artery ligation method, surgeries are divided into:

• Ligation of all thyroid arteries (superior and inferior) in continuity.
• Ligation of only the superior thyroid arteries.
• Surgeries without ligation of the main trunks in continuity (only vascular branches of the subfascial plexus and branches within the parenchyma and fibrous capsule are ligated).

Topographic anatomy and surgical approach

The patient is placed in the supine position, with a roll placed under the scapulae to ensure neck extension. Anesthesia may be local or general.

The surgeon makes a collar skin incision according to Kocher. The incision line runs 1.0–1.5 cm above the jugular notch of the sternum, between the anterior borders of the sternocleidomastoid muscles (m. sternocleidomastoideus).

During the formation of the approach, the following are sequentially dissected:

1. Skin.
2. Subcutaneous tissue.
3. Platysma (platysma).
4. Superficial fascia.

The resulting upper skin-subcutaneous-fascial flap is dissected upward to the level of the upper edge of the thyroid cartilage. Beneath it, the outer fascial capsule, formed by the visceral layer of the cervical fascia (4th according to Shevkunenko), is visualized. To access the organ, the parietal layer of the 4th fascia is also incised, exposing the proper capsule of the gland (tunica propria).

Technique of subtotal strumectomy according to Nikolaev

After establishing the approach, the surgeon proceeds to mobilize the lobes:

• Mobilization. The median and anterior jugular veins of the neck (located within or deep to the 2nd fascia) are isolated, clamped with two clamps, divided, and ligated. The 2nd and 3rd cervical fasciae are incised longitudinally in the midline, strictly between the sternothyroid and sternohyoid muscles.
• Muscle division. To improve access above the level of the skin incision, the sternohyoid muscles are transversely transected (for large goiters, the sternothyroid muscles as well). For this purpose, a Kocher probe is placed under the muscle, two clamps are applied, and the tissues between them are divided.
• Anesthesia and infiltration. Up to 10 ml of 0.25% procaine solution is injected beneath the capsule of the exposed gland. This provides a hydraulic dissection effect and blocks the nerve plexus.
• Resection. First, the isthmus is freed from the trachea and transected between Kocher clamps, followed by the pyramidal lobe (if present). When working with the lateral lobe, the incised fascial capsule is bluntly pushed posteriorly. The lobe is luxated into the wound (lower pole first, then upper). The tissue is excised in small portions while controlled with a finger, and blood vessels with the fibrous sheath are clamped separately.
• Suturing and hemostasis. Thorough hemostasis is performed, and the vascular ligatures in the stump are tied into a single knot. The edges of the preserved fascial capsule are sutured over the stump with a continuous catgut suture, giving it a "boat" shape. The wound is washed with a stream of procaine to remove toxic products released from the parenchyma.
• Wound closure. The stumps are covered with muscles. The sternohyoid muscles are sutured with U-shaped catgut sutures, the fasciae with interrupted catgut sutures, and the skin with interrupted silk or nylon sutures. A rubber drain is left in the wound for 24 hours.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Topography of the recurrent laryngeal nerve and anatomy of the "danger zone" of the neck.
• Blood supply to the thyroid gland and options for arterial ligation in continuity.
• Anatomy of the cervical fasciae according to V. N. Shevkunenko's classification (2nd, 3rd, and 4th fasciae).
• Mechanism of hydraulic tissue dissection with procaine solution.

Other topics in the «Neck Surgery» section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.