Plate 181

The indications for subtotal thyroidectomy are decreasing because of the lower incidence of endemic goiters, both colloid and nodular, and the increasing effectiveness of medical therapy in patients who present with thyrotoxicosis, whether this is due to Graves' disease or to nodular toxic goiter.

A definite indication for subtotal thyroidectomy is the removal of a solitary nodule in a young person, especially female, when the mass does not take up radioiodide on thyroid scan and hence is suspected of being malignant. A simple fine needle aspiration may yield a suspicious cytology. Total lobectomy ensures a better margin and allows pathologic examination of the excised thyroid lobe for multicentric foci should a malignant tumor be found. Many surgeons combine a total lobectomy on the involved side with a subtotal lobectomy on the alternate side.

The controversy as to whether surgical or medical treatment for thyrotoxicosis is desirable in patients younger than 35 to 40 years and in pregnant patients has yet to be resolved, but it is generally agreed that the use of radioactive iodine is contraindicated. Surgical removal should be considered if antithyroid drugs are tolerated poorly or required in large, prolonged doses and if thyrotoxicosis recurs after an apparently successful medication regimen. In the poor-risk patient or one who has had a recurrence of toxicity following previous thyroid surgery, medical therapy is usually the treatment of choice. Also, some pregnant patients may be best treated with antithyroid drugs in order to defer surgery until after the patient has delivered. However, thyroid replacement is given daily once the patient is euthyroid to prevent the development of a goiter in the fetus.

Subtotal thyroidectomy or total thyroidectomy is performed for an enlarged thyroid gland that produced pressure symptoms or an undesirable cosmetic effect (endemic goiter), for toxic goiters, and occasionally for inflammatory conditions such as Riedel's struma and Hashimoto's disease.

The only indication for emergency thyroidectomy is in that exceedingly rare situation where pressure symptoms develop rapidly due to intrathyroid hemorrhage. In all other situations thyroidectomy should be considered an elective procedure performed when the patient is in optimal physical health. This is true particularly in thyrotoxicosis.

Patients with thyrotoxicosis should be treated with antithyroid drugs until an euthyroid state is reached. Because the (thiourea) compounds block the synthesis of thyroxine but do not inhibit the release of the hormone from existing colloid stores, the time required for symptomatic improvement may vary widely from 2 weeks to as long as 3 months. The variability is in part related to the size of the gland, since large goiters usually contain more colloid. When the patient has become euthyroid, iodine—given as Lugol's solution, potassium iodide solution, or tablets or syrup of hydriodic acid—can be administered for 10 days before surgery (optional). If this procedure is followed, almost any thyroidectomy can be performed under optimal conditions. If significant tachycardia due to an increased intraoperative or postoperative release of thyroid hormone is encountered, propranolol should be used to control it.

Endotracheal intubation is preferred, particularly if there has been long-standing pressure against the trachea, substernal extension, or severe thyrotoxicosis. For the severely toxic or apprehensive patient, a short-acting intravenous barbiturate may be given in the patient's room to avoid undue excitement. General inhalation anesthetic agents are used.

The patient is placed in a semierect position with a folded sheet underneath the shoulders so that the head is sharply angulated backward (Figure 1). The head rest of the table can be lowered to hyperextend the neck further. The anesthetist should make certain that the head is perfectly aligned with the body before the line of incision is marked. Any deviation to the side may cause the surgeon to make an inaccurately placed incision.

The patient's hair may be covered with a mesh cap to avoid contamination of the field. The skin is prepared routinely. Before the incision is made, it may be accurately outlined by compressing a heavy silk thread against the skin. The incision should be made about two fingers above the sternal notch and should be almost exactly transverse, extending well onto the borders of the sternocleidomastoid muscles (Figure 2). In the presence of a large goiter, it should be made a little higher so that the final scar will not lie in the suprasternal notch. A short midline crosshatch may be made across the outlined incision to provide a guide to accurate approximation of the skin at closure (Figure 2). The site for the incision is then draped with sterile towels secured with towel clips at the four corners, similar to a routine abdominal draping. Transfixing sutures or staples may be placed through the towel into the skin in the middle of the incision on either side. This secures the towel at the center of the incision and avoids contamination when the flaps are reflected upward and downward. Skin towels sutured or clipped to the field may be eliminated by the use of a sterile transparent plastic drape that is made adherent to the skin with an adhesive spray. A large sterile sheet with an oval opening completes the draping.

The surgeon stands at the patient's right side, since it is customary to commence the procedure at the right upper pole. He or she should be thoroughly familiar with the anatomy of the neck, especially with the blood supply and anatomic relationships of the thyroid gland (Figures 3, 4, and 5). A thorough understanding of the anatomy of this region should lessen the complications of hemorrhage or injury to the recurrent laryngeal nerve, which may course through the bifurcation of the inferior thyroid artery, and injury to the parathyroids. A dry field is maintained if the various fascial planes are carefully considered during the procedure (Figure 3). The locations of the major blood vessels, the parathyroids, and recurrent laryngeal nerve are shown in Figures 3 and 5.

The surgeon applies firm pressure over gauze sponges to one margin of the wound, while the first assistant applies similar pressure to the opposite margin. In this manner the active bleeding from subcutaneous tissue is controlled and the margins of the wound are evenly separated. The skin incision is made with a deliberate sweep of the scalpel, dividing the skin and subcutaneous tissue simultaneously if the panniculus is not too thick. The belly of the scalpel should be swept across the tissues but not pressed into them. Bleeding vessels in the subcutaneous tissues are seized with hemostats; the large vessels are ligated, while small vessels are merely clamped and released or cauterized. Hemostats with finely tapered jaws that can be applied to the vessel alone are the best type to use, because they permit ligation without strangulation of a tab of surrounding fat. One or two mass ligatures may do no harm, but many strangulated bits of tissue cause induration and inflammation during healing since the avascular tabs must be absorbed. Electrocautery is preferred to control bleeding.

The incision is deepened to the areolar tissue plane just below the platysma muscle where an avascular space is reached. All active bleeding points are grasped with curved, pointed hemostats that are reflected upward or downward depending upon to which side of the incision they have been applied (Figure 6). Active bleeding and danger of air embolus may occur from accidental openings made into the anterior jugular vein if too deep an incision is made. Sharp dissection may be used alternately with blunt gauze dissection to facilitate the freeing of the upper flap (Figures 7 and 8). Usually, a small blood vessel will be encountered, high up beneath the flap on either side, which will produce troublesome bleeding unless it is ligated (Figures 8 and 9). The dissection goes up to the thyroid notch, exposing all of the thyroid cartilage, as well as down to the suprasternal notch. Outward and downward traction is then applied to the lower skin flap as it is freed from the adjacent tissue down to the suprasternal notch (Figure 9). At the very lowest part of the wound, care should be taken to avoid damage to the communicating arch connecting the two anterior jugular veins. If the veins or the arch is entered, the descending branches of the anterior jugular vein should be ligated below the level of the communicating arch in order to minimize the chance of air embolism (Figure 9).

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