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

Minimally invasive thyroid and parathyroid surgery: modifications for low-resource environments

Minimally invasive thyroidectomy (MIT) and parathyroidectomy (MIP) are gaining popularity in the current surgical practice. The need for specific equipment and technology is an obstacle in the low-resource environment. This article provides simple and practical guidance for surgeons practicing in low-resource environments to help them attain quality surgical practice, maintain patient safety, preserve available resources, and achieve the best outcomes.

Incidences of Hypothyroidism Associated With Surgical Procedures for Thyroid Disorders: A Nationwide Population-Based Study

Background and Aim: Limited information available about different types of thyroid surgeries with risk for postoperative hypothyroidism. This study aimed to investigate the risk of developing early and late-onset postoperative hypothyroidism in patients with thyroid disorders. Methods: We used a large cohort data from the Taiwan National Health Insurance Research Data Base (NHIRDB) and identified 9,693 (9, 348) patients from January 1998 to December 2010, admitted for thyroid disorder surgeries. We used the surgical procedures time as the index date. Our observational retrospective cohort study excluded the subjects diagnosed with hypoparathyroidism and hypothyroidism before any surgeries. We analyzed the data using the Cox regression model to calculate the hazard ratio. Result: Postoperative hypothyroidism associated with bilateral-total (HR, 4.27; 95% CI, 3.32-5.50), one-side total and another subtotal (HR, 3.16; 95% CI, 2.59-3.86), bilateral-subtotal (HR, 1.65; 95% CI, 1.37-1.98), and unilateral-total (HR, 1.17; 95% CI, 0.95-1.44) surgical procedures. The time intervals for thyroid disorders were 320 cases developed postoperative hypoparathyroidism in eight weeks, 480 cases the second month, and 1000 cases in the first year after surgery. Conclusion: Findings suggest that thyroidectomy was associated with transient postoperative hypothyroidism in thyroid disorder patients. The bilateral-total surgical procedure was strongly associated with temporary postoperative hypothyroidism.

Thyroid function after subtotal thyroidectomy in patients with Graves' hyperthyroidism

Background. Subtotal thyroidectomy is a surgical procedure, in which the surgeon leaves a small thyroid remnant in situ to preserve thyroid function, thereby preventing lifelong thyroid hormone supplementation therapy. Aim. To evaluate thyroid function after subtotal thyroidectomy for Graves' hyperthyroidism. Subjects and Methods. We retrospectively reviewed the medical records of all patients (n = 62) who underwent subtotal thyroidectomy for recurrent Graves' hyperthyroidism between 1992 and 2008 in our hospital. Thyroid function was defined according to plasma TSH and free T4 values. Results. Median followup after operation was 54.6 months (range 2.1–204.2 months). Only 6% of patients were euthyroid after surgery. The majority of patients (84%) became hypothyroid, whereas 10% of patients had persistent or recurrent hyperthyroidism. Permanent recurrent laryngeal nerve palsy and permanent hypocalcaemia were noted in 1.6% and 3.2% of patients, respectively. Conclusion. In our series, subtotal thyroidectomy for Graves' hyperthyroidism was associated with a high risk of postoperative hypothyroidism and a smaller, but significant, risk of persistent hyperthyroidism. Our data suggest that subtotal thyroidectomy seems to provide very little advantage over total thyroidectomy in terms of postoperative thyroid function.

Functional capacity of the thyroid autograft and heterograft: An experimental study

BACKGROUND

The aim of this study was to investigate the functional capacity of thyroid autografts/heterografts in a guinea pig model.

METHODS

A total of 24 guinea pigs were divided into 4 groups. Group A had only a thyroidectomy incision, and group B had total thyroidectomy. We performed autotransplantation in group C and heterotransplantation in group D. We monitored the guinea pigs for an 8-week period, with weekly measurements of free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH). At the final stage, the autografts/heterografts were histologically examined.

RESULTS

In group B, fT3/fT4 showed a gradual decrease; however, an increase of TSH was noted. In groups C and D, fT3/fT4 showed a gradual decrease, followed by a gradual increase until euthyroid levels; an exact opposite was noted for TSH. In histologic examination, there were functional thyroid follicles in all animals of groups C and D.

CONCLUSIONS

The autotransplanted/heterotransplanted guinea pig's thyroid tissue provides adequate thyroid function.

Recurrence of Graves' disease in thyroglossal duct remnants: relapse after total thyroidectomy

BACKGROUND

Ectopic thyroid tissue can be found anywhere between the foramen cecum and the normal position of the thyroid gland, most commonly located in the anterior cervical area, the region of the thyroglossal duct. Although thyroid cancer has been described frequently in thyroglossal duct remnants, thyroid dysfunction related to this tissue is rare. We report a patient with recurrent Graves' disease arising in a thyroglossal duct remnant.

SUMMARY

A 40-year-old woman with a history of total thyroidectomy for Graves' disease, presented with a slowly enlarging midline neck mass in association with clinical signs of hyperthyroidism. Serum-free triiodothyronine (6.6 pg/mL) and serum-free thyroxine (2.2 ng/dL) were elevated (normal range, 2.3-4.2 pg/mL and 0.9-1.8 ng/dL, respectively), and thyroid-stimulating hormone was suppressed (<0.01 mIU/mL; normal range, 0.35-5.50 mIU/mL). Neck ultrasonography showed a solid mass, localized at the infrahyoid area; radionuclide scanning confirmed an increased uptake at the same level. A 4 cm solid mass was removed by the Sistrunk technique. Microscopic examination revealed marked follicular hyperplasia, with tall cells, small follicles, scant, and scalloped colloid, in association with patchy lymphocytic infiltrate consistent with Graves' disease.

CONCLUSIONS

There appears to be no reason why thyroid cells within thyroglossal duct remnants should not be influenced by the thyroid-stimulating immunoglobulins of Graves' disease. Thyrotoxicosis resulting from this must be very rare, however, as were unable to find reports of patients with thyrotoxicosis due to Graves' disease in thyroglossal duct remnants. Although some thyroid tissue can be found within the thyroglossal duct in 1.6% to 40% of normal adults, the risk of thyroid dysfunction from this is far too low to justify new therapeutic approaches.

Surgical management of Graves' disease -10-year prospective trial at a single institution

The extent of thyroidectomy in Graves' disease is still controversial. In our institution, long term euthyroidism without thyroxine replacement therapy has been aimed and, thus, subtotal thyroidectomy has been employed. We prospectively studied whether the surgical outcome was improved by a strategy of leaving smaller thyroid remnants. Between 1989 and 1998, 1897 patients with Graves' disease were treated by subtotal thyroidectomy and their thyroid function could be determined 2 to 3 years after thyroidectomy. The 10-year period was divided into 3 parts, '89-'91 (Period 1, n = 690), '92-'94 (Period 2, n = 587) and '95-'98 (Period 3, n = 620). Different maximum thyroid remnant sizes were prospectively established for each period: up to 7 g left in Period 1, up to 6 g in Period 2 and up to 5 g in Period 3. Thyroid function 2 to 3 years after thyroidectomy and the occurrence of surgical complications were compared among the three groups. The relapse rate for Period 1, Period 2, and Period 3 was 14.1%, 12.6%, and 10.9%, respectively, and the rate of euthyroidism decreased and rate of hypothyroidism increased from period to period. Surgical complications increased in Periods 2 and 3. For preventing relapse, the strategy of reducing the thyroid remnant is effective. Subtotal thyroidectomy leaving 3-4 g remnant tissue is a suitable surgical option for Graves' disease.

Hypothyroidism following Hemithyroidectomy for Benign Nontoxic Thyroid Disease

Hypothyroidism following hemithyroidectomy for benign nontoxic thyroid disease is an underappreciated phenomenon. Up until recently, it was common practice for physicians to place post-hemithyroidectomy patients on thyroid suppression therapy during the immediate postoperative period. That practice began to fall out of favor as a result of two developments: (1) the publication of data that put into question the efficacy of levothyroxine therapy for preventing recurrent disease or thyroid growth and (2) a heightened awareness of the morbidity associated with levothyroxine. We conducted a retrospective chart-review study of 58 patients with benign nontoxic thyroid disease who had undergone hemithyroidectomy from 1994 through 2003 at one institution. Of these 58 patients, 14 (24.1%) had become hypothyroid after surgery, including 7 who had been so diagnosed 1 month postoperatively and 6 at 2 months. The remaining 44 patients were euthyroid. The mean preoperative serum thyroid-stimulating hormone (TSH) levels in the hypothyroid and the euthyroid groups were 2.39 and 1.07 μIU/ml, respectively—a statistically significant difference (p < 0.0001). A tissue diagnosis consistent with chronic inflammation (lymphocytic thyroiditis or Hashimoto's thyroiditis) was found in 50.0% of the hypothyroid patients, compared with only 6.8% of the euthyroid patients—again, a significant difference (p < 0.001). No significant difference was seen between the two groups with respect to age, sex, or the weight of the resected gland. We conclude that hypothyroidism after hemithyroidectomy is not an uncommon occurrence. Apparent risk factors include a high mean preoperative serum TSH level and tissue pathology consistent with chronic inflammation. It may be wise to follow patients with these identifiable risk factors more closely during the postoperative period; monitoring should include scheduled serial serum TSH draws.

Subtotal Thyroidectomy: A Reliable Method to Achieve Euthyroidism in Graves’ Disease. Prognostic Factors

BACKGROUND

Subtotal thyroidectomy is a widely accepted surgical procedure for Graves' disease. The purpose of this work is to evaluate functional long-term results and determine predictive prognostic factors of postoperative thyroid function.

STUDY DESIGN

This is a retrospective study conducted on 202 patients with Graves' disease undergoing subtotal thyroidectomy during the period 1979-2002. Predictive prognostic factors of final thyroid status were investigated by logistic ordinal regression, and probability of hypothyroidism during the years of follow-up was obtained by the Kaplan-Meier method.

RESULTS

Surgery controlled hyperthyroidism in 196 out of 202 patients (97%). The probability of hypo-, eu-, and hyperthyroidism at 5 years was 62.1%, 35.5%, and 2.4%, respectively. No statistical change in thyroid function occurred in the follow-up after 60 months. Multivariate analysis by a logistic ordinal regression analysis showed that weight of the remnant, age, and gender seemed to influence long-term thyroid function. The higher rates of euthyroidism were obtained when the remnant weight was between 6 and 8 g. No recurrence or persistence of hyperthyroidism occurred with remnant weights under 5 g.

CONCLUSIONS

Subtotal thyroidectomy controlled hyperfunction symptoms in 97% of our patients. Cure (euthyroidism) of Graves' disease patients should be attempted by leaving a thyroid tissue remnant between 6 and 8 g. Even more significant, our results suggest that euthyroidism rates could be improved by leaving a smaller remnant in elderly women and greater remnants in young men.

Subtotal Thyroidectomy for Benign Multinodular Goiter: A 6-Month Postoperative Study of the Remnant’s Function and Sonographic Aspect

BACKGROUND

The purpose was to evaluate the thyroid function after subtotal thyroidectomy.

METHODS

One hundred and nineteen patients operated on for multinodular benign goiter were included in this prospective study. Results of the surgical treatment were evaluated 6 months after operation by thyroid-stimulating hormone (TSH) assay and cervical echography.

RESULTS

Thyroid-stimulating hormone levels correlated inversely (r=-0.78) with the thyroid remnant volumes. Forty-seven patients presented with a hypoechoic aspect of the remnant. Isoechoic and hypoechoic remnant volumes were similar; however, 46 of the 47 patients with a hypoechoic remnant (97.9%) had TSH levels higher than 5 mU/l vs. 39 of the 72 patients (54.2%) with an isoechoic aspect. No predictive factor for the occurrence of this hypoechoic feature was found.

CONCLUSIONS

After sub-total thyroidectomy for benign multinodular goiter, the volume of the remnant is not the only determinant of the occurrence of postoperative hypothyroidism. The appearance of a hypoechoic aspect of the remnant is also a strong predictive factor for such an outcome. In this case the occurrence of hypothyroidism is quite constant whatever the volume of the thyroid remnant. Since this evolution toward a hypoechoic aspect of the remnant is unpredictable, our results are an additional argument in favor of total thyroidectomy for benign multinodular goiter.

A Prospective Randomized Comparison of Bilateral Subtotal Thyroidectomy Versus Unilateral Total and Contralateral Subtotal Thyroidectomy for Graves? Disease

To reduce the chance of recurrent hyperthyroidism, two methods of subtotal thyroidectomy were performed and compared. From January 1998 to December 2002, 340 patients were operated on with subtotal thyroidectomy. They were prospectively randomized into two groups. Group A included 166 patients and group B 174 patients. Group A patients had a 2.5 x 1 x 1 cm thyroid remnant on each side and group B patients had a 2.5 x 1 x 1 cm remnant on one side plus total lobectomy on the other side. Thyroid function tests including T(3), T(4), TSH, and antimicrosomal antibody (AMA) were checked preoperatively and in the follow-up period of 3 months, and later up to 26.4 +/- 1.1 months (mean +/- SE). The age, sex, duration of oral medicine, and blood loss of the two groups were not significantly different during surgery and the follow-up period. The operative time was less in group A (113 +/- 3.3 minutes) than that in group B (131 +/- 3.2 minutes) (p < 0.001). In the long-term follow-up period, recurrent hyperthyroidism was noted in 15 patients in group A and 3 patients in group B. The difference was significant (p = 0.003). Hypothyroidism was noted in 35 of the group A patients and in 46 of the group B patients. The differences between the two groups regarding hypothyroidism was not significant (p = 0.181). Multivariate logistic regression analysis revealed preoperative titers of AMA > or = 6400, which was the only factor affecting the incidence of hypothyroidism in the later follow-up period. In consideration of hypothyroidism, recurrent hyperthyroidism, and postoperative complications, subtotal thyroidectomy with total lobectomy plus subtotal lobectomy provides a better outcome than bilateral subtotal lobectomy.

Postoperative endocrine function in patients with surgically treated thyrotoxicosis

BACKGROUND

Endocrine function after surgery for thyrotoxicosis is difficult to predict. The operative morbidity and long-term thyroid function of patients surgically treated for thyrotoxicosis is presented, and factors postulated to affect long-term function are correlated with outcome.

METHODS

The clinical records of 289 consecutive patients who underwent surgery for thyrotoxicosis were reviewed. Indications for surgery, intraoperative findings, postoperative complications, and endocrine status 1, 2, and 5 years after surgery were analyzed. Sex, age, duration of medical treatment, weight of thyroid removed and preserved, and antimicrosomal/antithyroglobulin antibody status were correlated with outcome 5 years after surgery.

RESULTS

The incidence of permanent recurrent laryngeal nerve injury and hypocalcemia were 0.7% and 1.7%. The cumulative hypothyroid and hyperthyroid rates for the first, second, and fifth postoperative years were 13.8% and 3.5%, 14.5% and 4.8%, and 15.6% and 8.0%. All the prognostic variables analyzed did not achieve a significant correlation with outcome at 5 years by univariate and multivariate age- and sex-adjusted relative risk.

CONCLUSIONS

Failure from hypothyroidism develops early; recurrent hyperthyroidism increases with the number of years of follow-up. Patients undergoing subtotal thyroidectomy warrant long-term follow-up because of the inability to accurately predict postoperative function with consistently reliable prognostic factors.

Changes in serum TSH receptor antibody (TRAb) values in patients with Graves' disease after total or subtotal thyroidectomy

TSH receptor antibodies (TRAb) are generally regarded as mediators of thyroid stimulation in Graves' disease. In addition, a high serum TRAb value during pregnancy is one of the risk factors for intrauterine death, prematurity, and fetal or neonatal hyperthyroidism. Recently, correlations between a high serum TRAb value and endocrine opthalmopathy were also suggested. Surgical resection of the thyroid is usually followed by a reduction of serum TRAb levels in variable degrees. The relation between the extent of the thyroidectomy and the degree of reduction is still controversial. In addition, the changes in the TRAb value after total thyroidectomy (TT) over a long period of time have never been studied. We studied the changes in serum TRAb values after TT and subtotal thyroidectomy (ST) for more than 7 years. Forty-one patients with Graves' disease underwent TT, and 99 patients underwent ST. The serum TRAb values and the ratio of the patients who achieved normal values among each group (normalization rates of TRAb) at 3 and 6 months, 1, 3, 5 and 7 years after surgery were compared between the TT group and ST group. The mean preoperative TRAb values were not significantly different between the TT and ST groups, and the mean TRAb values measured 3, 6 and 12 months after surgery were not significantly different between the groups. However, the TRAb values measured 3, 5 and 7 years after surgery were significantly (p<0.05) lower in the TT group than in the ST group (16.7 +/- 3.3% vs 28.0 +/- 2.6%, 12.6 +/- 3.4% vs 29.3 +/- 3.8%, 5.6 +/- 0.9% vs 25.4 +/- 4.1%, respectively). The normalization rates of TRAb were not significantly different between the groups until 1 year after surgery. However, the normalization rates 3, 5 and 7 years after surgery were significantly (p<0.05) higher in the TT group than in the ST group (65.7% vs 42.4%, 77.3% vs 46.7%, 100% vs 59.1%, respectively). The surgical complication rates of TT were similar to ST except for permanent hypoparathyroidism. TT is a treatment option for Graves' disease, especially in patients with a high TRAb value who wish to have children or who have Graves' opthalmopathy.

Thyrotoxicosis--surgical management in the era of evidence-based medicine: experience in western India with 752 cases

The three modalities of treatment of thyrotoxicosis, antithyroid therapy (ATT), radio-iodine (I131) therapy and surgery are not cause-specific. In this paper, we describe our evolving experience with 752 thyrotoxic patients who underwent surgery during the last 40 years and discuss the current scenario with evidence-based data and observations wherever possible. Thyroidectomy was performed in 428 patients with Grave's disease (GD), 299 patients with toxic multinodular goitre, and 25 with toxic solitary nodules (TSN). Whereas 289 patients with GD had surgery for failed ATT, the other 139 had primary surgery for controversial or debatable indications such as poor socio-economic status, desire for early pregnancy, poor drug compliance and severe ophthalmopathy. Preoperatively, all patients were administered carbimazole or propylthiouracil. Non-selective b-blocker propranolol and Lugol's iodine were routinely given. In the 25 patients with TSN, hemithyroidectomy was performed. In all others, subtotal thyroidectomy (STT), was performed leaving behind 4 to 8 g of thyroid tissue: a larger amount was left behind in those with higher antithyroid antibody titres. During the last decade, 80 patients received near total thyroidectomy (NTT), mainly to minimize recurrence of thyrotoxicosis and to ameliorate severe eye signs. Because of our increasing experience, no significant increase in postoperative morbidity was encountered with NTT compared to STT. Transient hoarseness was observed in 53 patients with STT and only in two patients with NTT. Three patients with STT and one with NTT developed permanent hoarseness due to recurrent laryngeal nerve palsy; voice in these four was normalized by intraglottic injection of Teflon paste 6 months after the operation. In patients undergoing STT, transient hypoparathyroidism was encountered in 63, and permanent hypoparathyroidism in five. The corresponding figures for NTT were 12 and one, respectively. Of the 500 patients monitored for 1 year or more, hypothyroidism was observed in 135 and recurrent thyrotoxicosis in nine. In the same group of 500, exophthalmos was ameliorated in 130 of the 265 with positive eye signs. Nineteen glands exhibited features of severe Hashitoxicosis with marked destruction of acini and considerable lymphoid aggregates and follicles. Carcinoma was observed in three other thyroid glands.

[Is subtotal bilateral thyroidectomy still indicated in patients with Grave's disease?]

AIM OF THE STUDY

To evaluate the morbidity and the functional results of subtotal bilateral thyroidectomy in patients (TST) with Graves' disease.

PATIENTS AND METHOD

A retrospective study was performed in 128 patients. They were 23 males and 105 females with a median age of 34 years (range: 14-68). Weight of remnant tissue was between 4 and 5 g. Thyroid functional status was evaluated, at 3 months and after a follow-up period ranged from 1 to 5 years, by measurement of serum concentration of free T4 and/or free T3 and TSH.

RESULTS

They were no post-operative death. Surgical complications were 2 vocal cord palsies and 17 hypocalcemia (inf. to 2 mmol/L). After a median follow-up of 2 years, they were no longer any cases of vocal cord dysfunction and no case of permanent hypoparathyroidism. Functional results were established in 118 patients: 46 patients had clinical hypothyroidism (39%), 64 patients had latent hypothyroidism or euthyroidism (54.2%), and 8 had recurrent hyperthyroidism (6.8%).

CONCLUSION

These results suggest that TST with a remnant mass inferior to 5 g provides a low level of recurrent hyperthyroidism and allows to give no drug therapy to half patients. In our opinion, TST is still indicated in Graves' disease.

Trial of autotransplantation of cryopreserved thyroid tissue for postoperative hypothyroidism in patients with Graves' disease

BACKGROUND

Some patients with Graves' disease who select surgical therapy so they can discontinue antithyroid medication require lifelong levo-thyroxin (l-T4) replacement therapy because of irreversible postoperative hypothyroidism. The aim of this study was to enable the replacement of absent thyroid hormone through autotransplanted thyroid tissue that had been cryopreserved since the initial thyroid operation, and to release these patients from lifelong l-T4 administration.

STUDY DESIGN

At the time of subtotal thyroidectomy for Graves' disease, the surgical specimen was partially cryopreserved at -196 degrees C until it was used for autotransplantation. After obtaining sufficient informed consent, four patients with postoperative hypothyroidism underwent autotransplantation of cryopreserved thyroid tissues. These patients required 50 to 150 microg/day of l-T4 at 1.8, 3.4, 3.5, and 2.8 years after operation. For the transplantation, 2.5 to 3.5 g of cryopreserved thyroid tissue was autotransplanted into the forearm muscle of each patient.

RESULTS

In three of the patients, l-T4 administration could be discontinued and the clinical symptoms of hypothyroidism disappeared because of an improved serum thyroid-stimulating hormone level. Pathologic and immunohistochemical examinations of the thawed cryopreserved tissue demonstrated well-preserved thyroid structure and thyroglobulin-positive follicular cells and colloids, suggesting that the transplanted material was functional. In addition, 123I scintiscanning in patients 1 and 2 indicated an accumulation of radioactive iodine at the transplantation sites. One patient, who was able to discontinue l-T4 administration for 6 months, subsequently required l-T4 again because of recurrent hypothyroidism.

BACKGROUND

Despite a few remaining uncertainties that must be resolved before this procedure is optimized, autotransplantation of cryopreserved thyroid tissue promises to be a useful therapeutic procedure for treating permanent postoperative hypothyroidism in patients with Graves' disease.

The efficacy of thyroidectomy for Graves' disease: A meta-analysis

BACKGROUND

Surgery for Graves' disease was largely replaced in the mid-1900s by radioiodine and antithyroid drugs, due to the belief that they were more safe and effective. Since then, thyroid surgery has improved with preoperative drug therapy and modern operative techniques. Recent clinical studies of thyroidectomy for Graves' disease may not reflect outcomes accurately because of small sample size, especially when estimating ideal thyroid remnant size. The purpose of this study was to combine modern clinical trials and use meta-analysis to determine the overall efficacy of both total (TT) and subtotal thyroidectomy (ST) for Graves' disease, compare thyroid function and complications rates of TT and ST, and determine ideal thyroid remnant size.

METHODS

Meta-analysis was performed on published studies in which patients underwent either TT or ST for Graves' disease. Meta-analysis was performed by weighted least-squares linear regression. P < 0.05 was considered significant.

RESULTS

There were 35 studies comprising 7241 patients. Mean follow-up was 5.6 years. Overall, persistent or recurrent hyperthyroidism occurred in 7.2% of patients. TT was performed on 538 patients and hypothyroidism occurred in all cases. ST was performed in 6703 patients, 59.7% of whom achieved euthyroidism, 25. 6% became hypothyroid, and 7.9% had either persistent or recurrent hyperthyroidism. Permanent recurrent laryngeal nerve injury occurred in 0.9% of TT patients and 0.7% of ST patients (P = NS). Permanent hypoparathyroidism occurred in 1.6% of TT patients and 1.0% of ST patients (P = NS). There was an 8.9% decrease in hypothyroidism and 6.9% increase in euthyroidism for each gram of thyroid remnant (P < 0.0001 each).

CONCLUSIONS

Overall, thyroidectomy successfully treated hyperthyroidism in 92% of patients with Graves' disease. There were no cases of hyperthyroidism following TT. ST achieved a euthyroid state in almost 60% of patients with an 8% rate of persistent or recurrent hyperthyroidism. There was no significant difference in complication rates between TT and ST.

Results of subtotal thyroidectomy for Graves' disease

The objective of this study was to find the factors responsible for hypothyroidism after subtotal thyroidectomy for Graves' disease. Two hundred five patients who were operated on from July 1989 to December 1997 were studied. The mean age of patients was 33.4+/-11.0 (mean +/- SD) years, and 175 (85.4%) were female. Patients were prepared with an antithyroid drug and Lugol's solution preoperatively. Triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyrotropin-binding immunoglobulins (TBII) antimicrosomal antibodies (AMA = 100x 4(M-1)), and antithyroglobulin antibodies (ATA = 100x4(T-1)) were measured 1 week before patients were operated on. Operations were performed according to the standard procedure with 2.5x1x1 cm of thyroid tissue remaining on each side before approximating the thyroid capsule and pretracheal fascia. Hypothyroidism was defined by patients with overt hypothyroidism in laboratory data, and or with T4 to maintain T3 and T4. Two hundred two patients were checked 3 months after being operated on. Latent hyperthyroidism was found in 22, euthyroidism in 55, latent hypothyroidism in 91, hypothyroidism in 34 (16.8%) and none were in overt hyperthyroidism. After a follow-up period of 26.9+/-15 (mean +/- SD) months, 199 patients were reevaluated. Overt hyperthyroidism was found in 2 patients, latent hyperthyroidism in 12, euthyroidism in 97, latent hypothyroidism in 72, and hypothyroidism in 16 (8%). Factors having possible effects on hypothyroidism after longterm follow-up were analyzed. Patient's age, gender, body surface, premedicative T3 and T4, preoperative ATA, and TBII, and the weight of removed thyroid had no effect on the occurrence of hypothyroidism. Preoperative AMA levels, and finding more than 10 lymphoid infiltrations per 10 low-power fields (x40) were significantly different between the hypothyroid and nonhypothyroid groups. A high level of preoperative AMA was the only factor independently causing overt hypothyroidism in the follow-up period. Patients with high preoperative AMA levels have a higher risk of hypothyroidism if only 2.5x1x1 cm remnants are left on each side.

Factors affecting thyroid function after subtotal thyroidectomy for Graves' disease: case control study by remnant-weight matched-pair analysis

In order to determine whether there are any predictive factors, other than the amount of remnant thyroid tissue, for subsequent thyroid function after subtotal thyroidectomy for Graves' disease, thyroid function was assessed in 329 patients 3 years after surgery, and a case control study was carried out in euthyroid, hyperthyroid, and hypothyroid groups by remnant-weight matched-pair analysis. Factors that affected thyroid function 3 years after surgery were thyroid gland infiltration by lymphocytes and the thyrotropin binding inhibiting immunoglobulin (TBII) value in the hyperthyroid and euthyroid groups, and the free triiodothyronine (FT3) value at the time of surgery and lymph follicle formation in the thyroid gland in the hypothyroid and euthyroid groups. It is concluded that no single factor studied at surgery, other than the amount of remnant tissue, can predict thyroid function after subtotal thyroidectomy for Graves' disease.

Surgical treatment of Graves' disease: subtotal or total thyroidectomy?

BACKGROUND

The extent of thyroidectomy in Graves' disease is still controversial. We compared the outcome of two groups of patients with Graves' disease who underwent total and subtotal thyroidectomy, respectively.

METHODS

One hundred forty patients were treated by subtotal (ST, n = 80) or total thyroidectomy (TT, n = 60) between 1988 and 1994 for a large goiter or recurrence of hyperthyroidism after antithyroid drugs. Surgical complications, relapse of hyperthyroidism, and serum levels of antibodies were evaluated.

RESULTS

Thyroid-stimulating hormone receptor and thyroperoxidase antibodies significantly decreased in 44 of 60 and in 27 of 60, respectively, of TT patients and in 65 of 80 and 8 of 80, respectively, of ST patients. Thyroid-stimulating hormone antibody levels increased in three ST patients who had relapse of hyperthyroidism and in no TT patients; thyroperoxidase antibodies increased in nine ST patients (four with relapse of hyperthyroidism) and in no TT patients. Vocal cord palsy occurred in two ST (2.5%) and in 1 TT (1.7%) patients; hypoparathyroidism occurred in three ST (3.8%) and in two (3.3%) TT patients.

CONCLUSIONS

Total thyroidectomy does not present more complications with respect to subtotal thyroidectomy, but it avoids the worsening of thyroid humoral autoimmunity and the relapse of hyperthyroidism. Thus it could represent the treatment of choice in Graves' disease.

Early recurrence of hyperthyroidism in patients with Graves' disease treated by subtotal thyroidectomy

Prerequisites for surgical treatment of Graves' disease are that it can be done safely and that it is associated with a low incidence of recurrent hyperthyroidism. Early recurrence is especially undesirable. We studied 728 patients with Graves' disease treated by subtotal thyroidectomy using multivariate analysis in order to determine the factors related to early recurrence. The following factors were analyzed: age, sex, duration of medical treatment, weight of resected thyroid tissue, thyroid remnant size, preoperative level of thyroid-stimulating hormone (TSH) binding inhibitory immunoglobulin (TBII), and antimicrosomal hemagglutination antibody (MCHA). "Early recurrence" was defined as TSH suppression observed within the first year after surgery and continuing for at least 6 months. A total of 106 patients (14.6%) had early recurrence. Statistical analyses were performed by the chi-square test for univariate analysis and a logistic model for multivariate analysis. Significant factors were thyroid remnant size, MCHA, and TBII. These results indicated that TBII and MCHA are related to early recurrence of hyperthyroidism, and smaller remnant size is recommended for patients with a high MCHA titer or a high TBII level (or both) in order to avoid early recurrence.

Management of recurrent hyperthyroidism in patients with Graves' disease treated by subtotal thyroidectomy

If the aim of surgical treatment for Graves' disease is not permanent hypothyroidism, it is difficult to avoid recurrent hyperthyroidism completely. The management of recurrent hyperthyroidism, however, is neither easy nor obvious. Improvement in the sensitivity of TSH assay has allowed the diagnosis of latent hyperthyroidism. Little is known about the clinical course of latent hyperthyroidism. We studied the management and outcome of recurrent hyperthyroidism in patients with Graves' disease treated by subtotal thyroidectomy. Between January 1988 and August 1991, 1115 patients with Graves' disease were treated by surgery. Postoperative thyroid function was evaluated by free T3, free T4 and TSH measurements. One hundred seventy-five patients with suppressed TSH secretion for at least 6 months were categorized as having recurrent hyperthyroidism. Eighty patients (45.1%) also had elevated thyroid hormone levels, (group 1). The remaining 95 patients (54.9%) had normal thyroid hormone levels with suppressed TSH values (group 2). In group 1, 58 patients were treated with antithyroid drug (ATD), 12 with iodine and 10 with radioiodine (RI). Remission of Graves' disease was obtained in 22 patients (11 by ATD, 1 by iodine and 10 by Ri). On the other hand, patients in group 2 were followed up without medication, and spontaneous remission was observed in 21 of theln (22.1%). It was difficult to induce remission of overt recurrent Graves' disease by ATD or iodine. In contrast spontaneous remission could be obtained in some patients with postoperative latent hyperthyroidism.