Whither thyrotoxicosis?

Long-Term Effect of Surgery in Graves' Disease: 20 Years Experience in a Single Institution

The present study compared the long-term outcome of subtotal thyroidectomy (ST) to that of total thyroidectomy (TT) in Graves' disease (GD). Patients with GD requiring surgery were divided between two groups: ST and TT. Postoperative thyroid function (PoTF) changes, including hypothyroidism, euthyroidism, and hyperthyroidism, and surgical complications were analyzed 3 months and 2 years after surgery. During the study period, 350 GD patients underwent surgery, of whom 254 underwent ST and 96 underwent TT. In the ST group, the rates of hypothyroidism, euthyroidism, and hyperthyroidism were 92.5%, 6.7%, and 0.4%, respectively, after 3 months, and 86.1%, 8.6%, and 5.3%, respectively, after 2 years. No difference in the rate of surgical complication was observed between the ST and TT groups (p = 0.089). Most of the ST patients showed hypothyroidism after surgery, and euthyroidism was rare. The long-term outcome of ST included noticeable PoTF changes and recurrence of GD. These results suggest that TT should be considered as a treatment option in GD requiring surgery.

Advantages and disadvantages of surgical therapy and optimal extent of thyroidectomy for the treatment of hyperthyroidism

Surgery is excellent therapy for hyperthyroidism, with no mortality,and few complications or recurrences. It achieves euthyroidism rapidly and consistently, avoids long-term risks of radioactive iodine and antithyroid medications, provides tissue for histology,renders childbearing immediately possible, and allows absolute titration of thyroid hormone. Advancements such as preoperative preparation and intraoperative parathyroid hormone monitoring have decreased risks greatly and improved outcomes. Hartley-Dunhill procedure is the treatment of choice. Patients should be rendered euthyroid before operation to decrease thyroid vascularity, to improve surgical planes, and to prevent life threatening thyroid storm. Patients must be monitored carefully for hypocalcemia, a potentially serious complication. Patients will require lifelong thyroid hormone replacement. Radioactive iodine ablation should be considered for disease recurrence after surgery.

Highlights from endocrine surgical history

Endocrine surgery includes excision of diseased or sometimes normal endocrine glands and occasionally the transplantation of endocrine tissues. Male castration was performed for social reasons in prehistoric times, and thyroid operations were described during the twelfth century. Until the end of the nineteenth century most operations were undertaken to relieve the local effects of pathologic enlargement of the thyroid, ovaries, pituitary, and adrenals; and with the development of anesthesia, antisepsis, and effective hemostasis, thyroidectomy for benign, nontoxic goiter was perfected. Thyroid deficiency followed total thyroidectomy, and thyroid replacement therapy was developed. Toxic goiter was sometimes relieved by partial thyroidectomy. After the discovery of hormones early this century, knowledge of endocrinology increased, and many syndromes of hormonal excess were described. Surgeons began to operate to relieve them. Results improved with mastery of surgical technique, especially for operations on the thyroid, parathyroids, and pituitary; with the development of methods for diagnosis of syndromes and the localization of lesions; with teamwork; and with the use of hormones, drugs, and radiotherapy as alternative or additional forms of therapy before, during, and after operation. Notable advances followed adequate resection of thyroid tissue and the use of iodine and antithyroid drugs before operation for toxic goiter. The use of cortisone rendered adrenalectomy safe for the relief of cancer of the breast and prostate and of Cushing's syndrome. For about 40 years increasing numbers of surgeons have specialized in endocrine surgery as a discipline within general surgery, and results of treatment have improved greatly.

Retrospective analysis of prognostic factors affecting the thyroid functional status after subtotal thyroidectomy for Graves' disease

To determine the factors causing thyroid dysfunction after surgery for Graves' disease, we studied 321 patients who underwent subtotal thyroidectomy during the 7-year period from 1981 to 1987. Thyroid functional status was evaluated biochemically and the patients were divided into four categories: recurrent hyperthyroidism, euthyroidism, latent hypothyroidism, and hypothyroidism. The following factors were analyzed: sex, age at onset of the disease, indication for surgery, serum titer of antimicrosomal hemagglutination antibody (MCHA), weight of resected thyroid tissue, size of remnant thyroid relative to body surface area, pathological findings of lymphoid follicles, and lymphocytic infiltration in the thyroid tissue. Probabilities of failure (recurrent hyperthyroidism and hypothyroidism) were estimated by the Kaplan-Meier method. Prognostic factors for failure were identified by using Cox's proportional hazards model. The incidence of hyperthyroidism and hypothyroidism 5 years after subtotal thyroidectomy was 16.2% and 9.6%, respectively. Significant factors for hyperthyroidism were relatively large thyroid remnant, high serum titer of MCHA (greater than or equal to 1:3200), and age at onset of the disease less than 20 years. The significant factor for hypothyroidism was severe lymphocytic infiltration. The level of postoperative thyroid stimulating hormone (TSH)-binding inhibition immunoglobulins (TBII) in patients with recurrence was significantly higher than in patients in remission. It is reasonable to determine the amount of remnant thyroid tissue in relation to patient body surface area. Although subtotal thyroidectomy can induce immunological remission by reduction of antigen, if the remission disappears, that is if TBII increases, recurrence of hyperthyroidism may develop even in patients without the unfavorable factors.

Outcome of surgery for Graves' disease re-examined

The outcome of surgery for Graves' disease in terms of early and late morbidity was studied in 161 patients undergoing subtotal thyroidectomy in the 10-year period 1976-1985. Eighty of these patients had a minimum follow-up of 5 years. There was a low operative morbidity and a zero mortality. The weight of thyroid tissue preserved (in the range 5-10 g) influenced the prevalence of hypothyroidism at one year and at five years. There was a cumulative incidence of hypothyroidism which could not be reliably predicted from biochemical results during the first year. Over 60 per cent of patients with subclinical hypothyroidism at 4 months (63 per cent) or 1 year (70 per cent) did not subsequently need thyroxine replacement within 5 years. Patients remained at risk of developing recurrent toxicity indefinitely and the risk was significantly greater in patients with small goitres (less than 50 g). Our results may be improved by leaving larger remnants (9-10 g) in most patients and smaller remnants (2-4 g) in those with small glands in whom alternative treatment, which is to be preferred, is not acceptable. After subtotal thyroidectomy for Graves' disease lifelong follow-up is necessary.

[Surgical therapeutic concept of immune thyropathy]

73 patients with Graves' disease, surgically treated from 1975-1986, were investigated retrospectively. 43 patients, treated by subtotal thyroidectomy (Enderlen-Hotz) and a bilateral thyroid remnant of a total of about 8-12 g, were compared with 30 patients, treated by a modified subtotal thyroidectomy leaving a unilateral thyroid remnant of about 4-8 g, with respect to preoperative duration of disease, indications for surgical treatment, weight of resected specimens, operative complications and postoperative thyroid function. Surgical complications were similar in both groups. After subtotal thyroidectomy 14/43 patients (33%) displayed either recurrent hyperthyroidism (9/43, 21%) or local recurrence of Graves' goiter (3/43, 7%) or both (2/43, 5%). The modified subtotal resected group showed no recurrences of the disease. After subtotal thyroidectomy 11 patients were euthyroid without thyroid medication (26%) compared to only two patients (7%) after the modified procedure of subtotal thyroid resection. To prevent recurrences of goiter as well as hyperthyroidism and, on the other hand, to achieve euthyroid function postoperatively without need for thyroid replacement therapy, subtotal thyroidectomy with a small thyroid remnant of about 4-8 g is recommended for all patients with large goiter and a chronic recurrent course of the disease or with iodine induced thyrotoxicosis. Patients with non-recurrent Graves' disease but large goiter probably benefit from subtotal thyroidectomy with a larger thyroid remnant of about 8-12 g.

Current treatment of Graves' disease

In this review we have described the rationale for the appropriate treatment of patients with Graves' disease. Because the etiology of this disorder remains obscure, its management remains controversial. Since antithyroid drugs and radioiodine became readily available in the early 1950s, they have been widely used for the treatment of thyrotoxicosis, and the number of cases treated surgically has markedly decreased. However, almost four decades of experience have disclosed an unexpectedly high incidence of delayed hypothyroidism after radioiodine treatment and a low remission rate after antithyroid therapy. As a result, surgery is again being advocated as the treatment of choice. The three modalities of treatment have different advantages and disadvantages, and selection of treatment is of importance. In principle, we believe that for most patients a subtotal thyroidectomy should be performed after the patient has been rendered euthyroid by antithyroid drugs. We attempt to leave a thyroid remnant of 6 to 8 gm.

The selective beta 1-blocking agent metoprolol compared with antithyroid drug and thyroxine as preoperative treatment of patients with hyperthyroidism. Results from a prospective, randomized study

Despite the increasing use of beta-blocking agents alone as preoperative treatment of patients with hyperthyroidism, there are no controlled clinical studies in which this regimen has been compared with a more conventional preoperative treatment. Thirty patients with newly diagnosed and untreated hyperthyroidism were randomized to preoperative treatment with methimazole in combination with thyroxine (Group I) or the beta 1-blocking agent metoprolol (Group II). Metoprolol was used since it has been demonstrated that the beneficial effect of beta-blockade in hyperthyroidism is mainly due to beta 1-blockade. The preoperative, intraoperative, and postoperative courses in the two groups were compared, and patients were followed up for 1 year after thyroidectomy. At the time of diagnosis, serum concentration of triiodothyronine (T3) was 6.1 +/- 0.59 nmol/L in Group I and 5.7 +/- 0.66 nmol/L in Group II (reference interval 1.5-3.0 nmol/L). Clinical improvement during preoperative treatment was similar in the two groups of patients, but serum T3 was normalized only in Group I. The median length of preoperative treatment was 12 weeks in Group I and 5 weeks in Group II (p less than 0.01). There were no serious adverse effects of the drugs during preoperative preparation in either treatment group. Operating time, consistency and vascularity of the thyroid gland, and intraoperative blood loss were similar in the two groups. No anesthesiologic or cardiovascular complications occurred during operation in either group. One patient in Group I (7%) and three patients in Group II (20%) had clinical signs of hyperthyroid function during the first postoperative day. These symptoms were abolished by the administration of small doses of metoprolol, and no case of thyroid storm occurred. Postoperative hypocalcemia or recurrent laryngeal nerve paralysis did not occur in either group. During the first postoperative year, hypothyroidism developed in two patients in Group I (13%) and in six patients in Group II (40%). No patient had recurrent hyperthyroidism. The results suggest that metoprolol can be used as sole preoperative treatment of patients with hyperthyroidism without serious intra- or postoperative complications. Although the data indicate that the risk of postoperative hypothyroidism is higher after preoperative treatment with metoprolol than with an antithyroid drug, a longer follow-up period than 1 year is needed to draw conclusions regarding late results.

[Operative strategy in thyroid autonomy and Basedow hyperthyroidism]

The different extra- and intrathyroid origin of hyperthyroidism, the advantages of the surgical procedure and the criteria for the extent of thyroid resection determine the operative tactics. For both forms of hyperthyroidism we recommend a rather extended resection of the diseased thyroid gland in order to prevent recurrent hyperthyroidism and recurrent thyroid growth as well. These recurrences require subtotal thyroidectomy for Graves' disease, monolateral partial lobectomy for a so-called toxic adenoma and bilateral partial lobectomy for toxic multi-nodular goiters. With these procedures lesions of the recurrent nerves and parathyroid glands can be prevented.

Surgery for thyroid disease

Thyroidectomy is the keystone of management in most patients with thyroid cancer, and has unique advantages in many cases of hyperthyroidism. The role of thyroidectomy in these two conditions is considered, with specific discussion of indications, extent of operation, complications, and technique.

Surgery for thyrotoxicosis

Recent reports have suggested the use of radio-iodine for the treatment of all cases of thyrotoxicosis. This paper evaluates the results of 627 patients undergoing subtotal thyroidectomy with a mean follow-up of 5 X 8 years. The most common complications were hypothyroidism (26 X 6 per cent) and recurrent thyrotoxicosis (2 X 6 per cent). Permanent hypocalcaemia occurred in 8 cases (1 X 4 per cent) and one patient developed a permanent, though asymptomatic, unilateral cord palsy (0 X 2 per cent). Ultimately all patients receiving radio-iodine appear to become hypothyroid and there is continued worry about possible thyroid malignancy. Almost 70 per cent of our cases were free of complications and euthyroid and we therefore believe that surgery remains the treatment of choice for thyrotoxicosis. We also discuss the difference in results between Graves disease and toxic multinodular goitre.

Nadolol and potassium iodide in combination in the surgical treatment of thyrotoxicosis

With the two aims of rapidly reducing circulating thyroid hormone levels and controlling the symptoms of thyrotoxicosis, we have prepared 17 thyrotoxic patients for subtotal thyroidectomy, using a combination of potassium iodide administered for 10 days and the long acting beta-adrenoceptor antagonist nadolol. All 17 patients had normal serum thyroxine levels after 10 days of such treatment although 10 still showed elevation of serum tri-iodothyronine and considerable elevation in the most severely toxic patient. All patients were, however, clinically euthyroid preoperatively. Nadolol was administered once daily, hence avoiding the problems of drug administration in the immediate postoperative period, and plasma nadolol concentrations were high throughout the perioperative period. Serum thyroxine and tri-iodothyronine levels were significantly lower and reverse tri-iodothyronine levels higher 24 h postoperatively than before operation. All patients remained stable throughout the perioperative period. We conclude that this regimen has a number of advantages in the preparation of patients for thyroidectomy, in reducing the degree of thyrotoxicosis, in convenience of drug administration and in ensuring adequate circulating concentrations of beta-adrenoceptor antagonist whilst still retaining a relatively short preoperative phase of drug treatment.

Propranolol and thyroidectomy in the treatment of thyrotoxicosis

For decades, the preparation of a hyperthyroid patient for surgery took several weeks or months utilizing thyroid blocking agents and iodine. In 1973, a preliminary report of 20 patients with hyperthyroidism treated with propranolol and thyroidectomy was presented. It was found that a thyrotoxic patient could be prepared for surgery, in an emergency, by intravenous propranolol in less than an hour, or electively by oral propranolol within 24 hours. Since then, 140 additional patients have been similarly treated. It continues to be true at this institution that propranolol, a beta-adrenergic blocking agent, effectively neutralizes the symptoms of autonomic hyperactivity, including sweating, tremor, fever, dilation of blood vessels, and increased pulse rate without significantly affecting thyroid function. An average dose of 160 mg/day was used, with a range of 40 to 320 mg/day. In none of these patients was iodine used; in fact, its use with propranolol is considered unnecessary. A subtotal, near total, or total thyroidectomy was done in all patients, resulting in a 55% incidence of hypothyroidism. There was no postoperative thyroid storm, nerve injury, or permanent hypoparathyroidism. It is believed that the administration of propranolol alone provides a rapid, safe, and effective preparation of the thyrotoxic patient for thyroidal or extrathyroidal surgical procedures during the perioperative period.

Surgical treatment for Graves' disease: a long term follow-up of 325 patients

Postoperative thyroid status was classified into 6 categories on the basis of serum free thyroxine index (FTI), serum triiodothyronine (T-3) and serum TSH concentration. Review of 325 patients who underwent thyroidectomy for Graves' disease more than 4 years previously showed that 25 patients (7.7 per cent) had recurrent hyperthyroidism. Six patients (1.8 per cent) were classified as equivocal hyperthyroid since either FTI or T-3 was above the normal range. Two hundred and twenty-two patients (68.3 per cent) were unequivocally euthyroid and 33 patients (10.3 per cent) were euthyroid with elevated TSH levels. Twenty patients (6.2 per cent) were equivocal hypothyroid since either their FTI or T-3 values were below the normal range and TSH were increased. Hypothyroidism was present in 19 patients (5.8 per cent), of whom 11 had no clinical manifestation of thyroid dysfunction. The incidence of hypothyroidism did not correlate with the intervals between operation and review. The second review, performed in 189 patients 18 months after the first, showed that there was a change in thyroid functional status in 46 patients, of whom 32 had an increased level of function, including one hypothyroid and 7 equivocal hypothyroid patients who became euthyroid spontaneously. Thus postoperative hypothyroidism in some patients can recover without medication. Also thyroid function in some postoperative patients is not maintained at a fixed level but may fluctuate.

[Basedow-Graves' disease: operative treatment (author's transl)]

For hyperthyroidism of Basedow's or Graves' type, surgery is the treatment of choice for large goiter, particularly in the presence of mechanical irritation, for cases of unsuccessful conservative medical treatment, or for cases where 131I-irradiation is contraindicated. The operative risk is less than 1%. Adequate preoperative antithyroid medication is obligatory because surgery should be carried out under euthyroid conditions.

Hypothyroidism following partial thyroidectomy for thyrotoxicosis and its relationship to thyroid remnant size

One hundred and twenty-two patients were reviewed 1-7 years after partial thyroidectomy for thyrotoxicosis by two surgeons who had left thyroid remnants of different size. There was no significant difference in the prevalence of hypothyroidism or in the serum levels of thyroxine, tri-iodothyronine or thyroid-stimulating hormone between the two groups of patients. The overall prevalence of hypothyroidism was 16 per cent.