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Substernal Goiter
COLLECTIVE REVIEW
Substernal Goiter Mark R. Katlic, M.D., Chiu-an Wang, M.D., and Hermes C. Grillo, M.D. ABSTRACT The literature on substernal goiter from the seventeenth century to the present is reviewed. Substernal goiter may be defined as any thyroid enlargement that has its greater mass inferior to the thoracic inlet. Truly ectopic mediastinal goiters are rare, and most substernal goiters arise from and maintain some attachment to the cervical thyroid gland. Patients are generally in the fifth decade of life, and women predominate. Most patients experience dyspnea, stridor, or dysphagia, but 15 to 50% are asymptomatic; symptoms are often positional, and acute stridor may occur. Ten to twenty percent have no cervical mass or tracheal deviation on examination, and virtually all patients are euthyroid. Standard chest roentgenograms are often diagnostic, but computed tomographic or radioactive iodine scans may be helpful. The presence of a substernal goiter in all but the highest-risk patients is an indication for resection, usually through a cervical collar incision; an occasional patient will require sternotomy or thoracotomy. Death or major complications should be rare postoperatively. Substernal goiters are adenomatous and benign, but carcinoma occurs in 2 to 3% and may be occult. Patients should be followed closely, as these goiters may recur.
The extirpation of the thyroid gland for goitre typifies, perhaps better than any operation, the supreme triumph of the surgeon‘s art. A feat which today can be accomplished by any really competent operator without danger of mishap and which was conceived more than 1000 years ago . . . William Stewart Halsted [l] Substernal goiters share a number of properties with their solely cervical counterparts. They grow slowly over many years, cause few symptoms until they are quite large, are mostly (but not universally) benign, and are readily amenable to operative cure. Extension of a substernal goiter into the unyielding thoracic inlet, however, greatly amplifies the mechanical effect of the mass and threatens the patient’s life. Dyspnea and dysphagia are more likely, risks of acute asphyxiation or superior vena caval syndrome are increased, and diagnosis and resection become more difficult. Many of the world’s most influential surgeons, including Billroth, Kocher, Halsted, and Gross, have written about substernal goiters, and the last 50 years have seen
From the General Thoracic Surgical Unit and the General Surgical Services, Massachusetts General Hospital, and the Department of Surgery, Harvard Medical School, Boston, MA. Address reprint requests to Dr. Katlic, 35 W Linden St, Wilkes-Barre, PA 18702.
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a profusion of articles on various aspects of this condition. The present review was undertaken to relate those chapters in the colorful history of goiter surgery that pertain to the substernal group, and to s ~ - i m a r i zand e bring perspective to the current wealth c material on these goiters.
Historical Background Surgeons have been heroically removing goiters since the sixteenth century-perhaps as early as 900 A.D. [1]but these have been isolated instances with disastrous results that were usually due to unremitting hemorrhage. In 1864, Gunther [2] described a case from 1770 in which ”after several fruitless attempts at ligation of the arteries, the severe hemorrhage was controlled by compression day and night during eight days by persons alternating with each other at the task.” He listed a total of 41 operations for struma lymphatica, the common goiter, reported in the literature through 1861. Substernal goiter had been described anatomically in 1749 by Haller [3] but probably the first written account in which an extirpated goiter was clearly beneath the sternum was that of Klein [4] in 1820. The next year Hedenus [5] reported removal, without a death, of 6 goiters causing suffocation. This feat was performed without benefit of hemostatic clamps or anesthesia, and Hedenus’s record was unmatched for the remainder of the century. As late as 1866, Gross [6] wrote in A System Of Surgery:
“10 sensible man will, on slight consideration, attempt to extirpate a goitrous thyroid gland. If a surgeon should be so adventurous or foolhardy as to undertake the enterprise, I shall not envy him his feelings while engaged in the performance of it, or after he has completed it, should he be so fortunate as to do this. Every step he takes will be environed with difficulty, every stroke of his knife will be followed by a torrent of blood and lucky will it be for him if his victim live long enough to enable him to finish his horrid butchery. During this time Billroth had performed 20 such operations with 8 deaths in Zurich. At least 1 of these goiters was substernal, for he noted that ”the trachea, especially at its entrance into the chest, was compressed by many nodules in the thyroid gland” [7]; this patient died 48 hours after total thyroidectomy. Billroth‘s next 48 cases of goiter, in the period from 1877 to 1881 and after introduction of antiseptic principles, resulted in only 4 deaths. These numbers are virtually identical to Halsted’s experience in the United States up to 1883 [l]. It was Kocher, however, who utilized sound principles of anesthesia, hemostasis, and antisepsis to show that goiter surgery could be made reproducibly safe; his work influenced European disciples as well as Halsted. The mortality for his series of 225 patients with benign
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A
B
Fig 1. (A, B ) Max Brodel illustrations from “The Operative Story of Goitre” by Halsted [I]. (Reproduced with permission of the Johns Hopkins University Press.)
brisk hemorrhage and infection but safe, anatomical dissection and grateful patients. As Halsted [l]noted, ”In the story of the development of the operation for goitre the essential history of surgery is comprised.”
goiter was 0.8% [8]. Reporting on a second series of 1,000 patients in 1901, in which there were 4 deaths among 929 patients with benign goiter, Kocher [9] wrote of the special problems of intrathoracic goiters. He found hemorrhage to be a great problem in this situation and recommended double ligation of the accessible vessels from above. He constructed special forceps and a spoon for delivering the substernal mass, and he advised fragmenting the tumor if necessary. At the time of his death in 1917, approximately 5,000 goiters had been removed at Kocher’s clinic [l]. Another great influence on Halsted, and hence on American surgery, was Mikulicz [lo]. By 1886, this careful surgeon had removed 25 goiters without a death. That same year, he performed an operation he termed ”resection” rather than ”extirpation,” in which he removed the entire left thyroid lobe and part of the substernal right lobe. Halsteds 1920 monograph [l],with its critical analysis of 375 articles and the unsurpassed Max Brodel illustrations of technique (Fig l), remains the landmark work on the history of goiter surgery. Also in 1920, Lahey [ l l ] manifested his early interest in the thyroid gland with his first published paper, “Diagnosis and Management of Intrathoracic Goiters.” The turning point in goiter surgery occurred in the last part of the nineteenth century. Before this time, patients sitting upright in chairs underwent painful extirpation without anesthesia and often died of hemorrhage or sepsis. With the introduction of anesthesia, principles of hemostasis, and antisepsis came dramatic improvements in results that led surgeons to expect not
Characteristics of Substernal Goiter Definition Substernal goiter may be defined as any thyroid enlargement that has its greater mass inferior to the thoracic inlet. This condition has also been called retrosternal, subclavicular, intrathoracic, mediastinal, aberrant, or wandering goiter; spring goiter; goiter mobile; and goiter plongeant. Various criteria have been proposed for including goiters in the substernal group. Lindskog and Goldenberg [12] termed a goiter substernal or mediastinal if its lower border was found radiographically to reach the level of the transverse process of the fourth thoracic vertebra or lower. Crile [13] considered a goiter truly intrathoracic only if it extended downward as far as the arch of the aorta. Other authors [14-161 have considered a goiter partially intrathoracic when its greater mass was inferior to the thoracic inlet and totally intrathoracic when its entire mass was inferior to the thoracic inlet. A further subdivision of the totally intrathoracic group comprises goiters that Rives [17] termed mediastinal aberrant and Falor and colleagues [18] called primary intrathoracic. These are totally intrathoracic goiters that have a blood supply derived from intrathoracic arteries, that drain into intrathoracic veins and that maintain little or no connection to the cervical thyroid gland; they are quite rare. It seems reasonable to call a goiter substernal or intrathoracic if 50 to 100% of its mass lies inferior to the thoracic inlet; the term aberrant should be reserved for goiters that neither receive a cervical blood supply nor maintain any connection to the cervical gland.
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lncidence Reeve and co-workers [19, 201 found on the basis of mass roentgenographic surveys of the general population of Sydney, Australia, that the incidence of substernal goiter was 1 in 5,040; among women more than 45 years old, it was 1 in 2,030. Intrathoracic goiters comprised 5.3% of 1,064 mediastinal tumors reported by Wychulis and associates [21]. Most authors, however, describe the incidence of substernal goiter in reference to the total number of thyroidectomies performed. Reported incidences of substernal goiter in relation to the total number of patients undergoing thyroidectomy vary according to definition, but range from less than 1% [13] to more than 20% [22]. Goiters that reside completely within the thorax comprise less than 1%of all goiters removed surgically [14, 16,23-251. In 2 to 14% of patients undergoing thyroid surgical procedures, the bulk of the goitrous mass is in the chest [16, 24,26-301. Etiology Two possibilities exist for the presence of this thyroid neoplasm in an abnormal location: (1) the goiter arises from the cervical thyroid tissue and grows inferiorly through the thoracic inlet, and (2) the growth arises from aberrant thyroid tissue already situated in the mediastinum. Although most authors agree that both concepts are theoretically possible, some argue more or less strongly about the existence of such aberrant thyroid tissue. Certainly the vast majority of substernal goiters arise from the cervical thyroid gland, descending along a fascia1 plane into the superior mediastinum. Lahey [31], claiming that each of the 24,000 goiters he had seen arose in the neck, called this a "space with no bottom"; cervical adenomas were directed into this superior mediastinal space by the swallowing mechanism. Many authors found that every substernal goiter they removed maintained some connection to the cervical gland [13, 15, 16, 24, 27, 32, 331 and generally received blood supply from the cervical thyroid vessels. Three cases have been reported of large substernal goiters that descended to touch the diaphragm [34-361, yet even these maintained a pedicle connection to the cervical gland. For a substernal or intrathoracic goiter to have arisen from aberrant thyroid tissue in the mediastinum, its blood supply should be from thoracic vessels and it should maintain no connection to the cervical gland. Ectopic thyroid tissue has been found from the tongue to the diaphragm [37], presumably carried there during embryological development of the thyroid and thymus. In a review in 1947, Rives [17] found 14 unquestionable cases of aberrant mediastinal goiters and added 3 cases of his own. Since that time, many authors have reported 1 or 2 individual cases that could be considered truly aberrant [14, 18, 38-45]. The blood supply in these goiters arose from the aorta, subclavian artery, internal mammary arteries, thyrocervical trunk, or innominate artery. The venous drainage was generally into corresponding thoracic veins. Occasionally, however, even
cervical goiters may receive some blood supply from thoracic vessels [15, 421. The presence or absence of a fibrous connection to the cervical gland seems less important; a band of tissue might exist regardless of embryological versus adult migration of the aberrant tissue. To all intents and purposes, then, substernal goiters arise from and maintain some attachment to the cervical thyroid gland. Mediastinal goiters arising from truly ectopic thyroid tissue exist but are extremely rare.
Location Substernal goiters arise equally from the right and left lobes of the thyroid gland [12, 24, 26, 281, although in an occasional series [23], right-sided goiters predominate. DeAndrade [32]pointed out that some goiters arise from the left thyroid lobe but grow into the right mediastinum because of the presence of the aortic arch. Most substernal goiters reside in the anterolateral mediastinum; few are limited to the true anterior pretracheal space [46]. In 1949, Sweet [47] drew attention to those goiters limited to the posterior mediastinum, and subsequent reports [24, 26, 271 showed that goiters in this position comprise 10 to 15%of all substernal goiters. Sweet believed that these posterior descending goiters arose not from the inferior pole of the lateral thyroid lobe but from its posterior and lateral aspect. The largest experience with goiters in the posterior mediastinum is that of DeAndrade with 128 cases [32]. Age and Sex Distribution Substernal goiters are most common in patients in the fifth decade of life [12, 13,22, 26, 28,42,47, 481. Pemberton [25] reported the youngest patient with substernal goiter (15 years old). Other authors [49, 501 reported patients more than 80 years of age. Female patients predominate, and the female :male ratio may be as high as 9: 1 (161, although it is typically 3 or 4: 1 [27, 28, 32, 391. In a few series, there were equal numbers of men and women [12, 24,441 and in one [48], a slight predominance of male patients. Symptoms The most common symptoms associated with substernal goiter are dyspnea, stridor, dysphagia, hoarseness, cough, wheeze, and the presence of a bothersome cervical mass. These symptoms do not differ greatly from those of patients with cervical goiters [51] but may be more severe because of the presence of the mass within the bony thoracic inlet. Most investigators agree that respiratory symptoms predominate, although dysphagia may occur in up to one-third of patients [12, 16, 261. Fifteen to 50% of patients have no symptoms whatsoever [12, 13, 24, 26, 39, 48, 521. In 1921, Pemberton [25] drew attention to the positional nature of these symptoms in some patients, and his findings have been reproduced in most subsequent series. A subset of patients will complain of dyspnea, stridor, or facial flushing only when they are supine, when their arms are raised or their neck is extended, or
394 The Annals of Thoracic Surgery Vol 39 No 4 April 1985
when they are looking to the right or the left; these symptoms result from the goitrous mass being drawn into the thoracic inlet. A smaller group of patients (2 to 3%)will experience the acute onset of stridor [16, 20, 26, 27, 30,44, 501. This may be due to incarceration of the mass in the thoracic inlet or to the occurrence of hemorrhage either spontaneously [51] or after trauma [27]. Acute stridor may be life-threatening in this situation, as neither endotracheal intubation nor tracheostomy relieves the obstruction in every instance [53]. Central nervous system symptoms due to carotid artery compression are extremely rare. Lesoin and colleagues [54] reported the case of a patient with a congenital anomaly of the carotid arteries and compression by a substernal goiter; the patient’s frequent transient ischemic attacks with left hemiparesis were cured by thyroidectomy. Lamke and associates [48] described cerebral edema and a large substernal goiter compressing the right carotid artery in a patient who died on induction of anesthesia.
Signs Physical findings in patients with substernal goiter include cervical mass, tracheal deviation, hoarseness, obesity, and dilated veins. Most patients have a goitrous mass palpable in the neck, but 10 to 20%have no cervical abnormality [12, 26, 30, 39, 42, 521. In other patients, the mass may be evanescent, appearing when the arms are elevated, when the patient is supine, or with coughing or swallowing [26, 521. Clute and Lawrence [33] pointed out that inability of the examining physician to palpate the lower thyroid pole was a clue that substernal extension of the goiter might exist. Dilated veins and facial flushing may also be positional. Most cases of true superior vena caval obstruction are due to malignancy [55], but a rare case is the result of substernal goiter [15, 49, 55-61]. Superior vena caval obstruction by an intrathoracic goiter may also result in so-called downhill esophageal varices [62-641. These varices may serve as collaterals either to bypass superior vena caval obstruction through the azygos vein or to drain systemic blood from the head and neck to the portal vein when both the superior vena cava and the azygos system are occluded. Such patients may show signs of gastrointestinal bleeding in the absence of the stigmata of portal hypertension. Pain or tenderness associated with substernal goiter is rare and may indicate thyroid malignancy or, in one reported instance [65], abscess formation. Pathological Characteristics Substernal goiters are adenomatous by nature, being multinodular or composed of one or more follicular adenomas [12, 13, 27, 30, 31, 39, 521. Hashimoto’s thyroiditis may occur [26]. Old hemorrhage, calcification, cyst formation, fibrosis, and focal thyroiditis are occasionally noted. Diameter of the goiter may range from 4 to 18 or 19 cm, but the average is about 6 to 10 cm. Goiter
weights range from 25 to more than 1,000 gr [52]; the average reported weight is from 100 to 200 gr. Carcinoma occurs in 2 to 3% of substernal goiters [16, 261. Many authors have reported 1 or 2 patients with carcinoma [12, 24, 25, 27, 30, 32, 481, and in several of these patients, the carcinoma was occult [20, 261. The fact that these carcinomas can grow considerably with no marked change in patient symptoms or signs argues for removal of all substernal goiters.
Diagnosis of Substernal Goiter Laboratory Findings In 1939, Crile [13] reported that 50% of his substernal goiter patients were clinically hyperthyroid, although he admitted that in some instances it might be difficult to determine whether dyspnea in these patients resulted from mechanical or metabolic effects of the goiter. In the 1950s, McCort [24] and Ellis and colleagues [52] found that fewer than 10 to 15% of substernal goiter patients had documented elevations in basal metabolic rate. In more recent series [27,44, 661, only an occasional patient has been found to have thyrotoxicosis. Two groups of investigators [26, 481 have measured thyroid function test results in substernal goiter patients. Lamke and co-workers [48] found that 3 of 29 patients were hyperthyroid on the basis of laboratory testing of thyroid function. Katlic and associates [26] reported preoperative thyroid function testing in 52 of 80 substernal goiter patients; 51 were euthyroid and 1, who had had prior neck radiotherapy, was mildly hypothyroid. Pulmonary function evaluation such as spirometry or flow-volume loop testing will usually show evidence of tracheal obstruction [36, 481. Reeve and colleagues [20] noted abnormally low vital capacities in nearly all of the 27 substernal goiter patients they tested. Even asymptomatic patients who have only cervical goiter are likely to show upper airway obstruction on flow-volume loop testing [67]. Radiographic Findings Patients with substernal goiter may be studied by routine chest roentgenography, linear tomography, computed tomography (CT), barium swallow esophagography, or radioisotope scanning using iodine or technetium. Most authors believe that the standard chest roentgenogram is the most useful radiographic study in terms of cost versus benefit, and some [26, 391 think that it is the only study required for the routine diagnosis of substernal goiter. McCort [24] listed the important roentgenographic findings as follows: displacement of the trachea by the mass; displacement of the trachea beginning high in the neck, frequently at the larynx, with some tilting of the larynx; compression of the trachea; calcification within the goiter; a smooth or only slightly nodular outline of the tumor; and reflection of the mediastinal pleura below the goiter. The addition of fluoroscopy helps determine whether the mass moves
395 Collective Review: Katlic, Wang, and Grillo: Substernal Goiter
A
Fig 2. Linear tomograrns of posterior mediastinal goiter displacing and compressing trachea ( A ) laterally and ( B ) anteriorly.
with swallowing; the goiter moved with deglutition in 84% of McCort’s patients. The presence of calcification does not exclude malignancy, as the single carcinomatous goiter in this series was heavily calcified [24]. Linear tomography accentuates the findings of the plain chest roentgenogram (Fig 2), but for complete evaluation of the mediastinum, CT is unsurpassed (Fig 3). Bashist and co-workers [46] and Glazer and associates [68] recently described the CT findings in representative cases of intrathoracic goiter as follows: continuity of the mediastinal mass with the cervical thyroid; well-defined borders; focal punctate, coarse, or ringlike calcifications; nonhomogeneity, with particular nonenhancing low-density areas; relatively high precontrast attenuation numbers compared with adjacent muscles; enhancement after administration of iodinated contrast material; prolonged enhancement after contrast material administration; and characteristic patterns of extension of goiter into the mediastinum. In 1950, Adams [69] stressed the importance of routine barium swallow esophagography in the evaluation of mediastinal masses. Clute and Lawrence [33] believed that the substernal goiter rarely affects the course of the esophagus, but others (24, 261 found esophageal deviation or compression in up to one-third of patients. Alfonso and co-workers [51] reported compression of the cervical esophagus in 53 of 273 patients with benign cervical goiters alone. Rietz and Werner [44] observed that
B
in all of their 12 patients with posterior goiter, the esophagus was displaced. The role of radioisotope scanning of the thyroid in these patients is controversial. Irwin and colleagues [70] found that preoperative iodine 131 scanning was diagnostic in all of their 27 patients with documented substernal goiter. Others [46, 681 found I3’I scanning less useful in that a negative scan could occur in the presence of substernal goiter because there is little or no functioning thyroid tissue in the substernal component. Nejatheim and Strashun [71] pointed out that if 13’1 scanning is to be performed, it must precede contrast CT evaluation, since expansion of the body pool of iodine by contrast infusion interferes with normal thyroid uptake of the scanning dose of radioactive iodine. It seems
Fig 3. Computed tornogram of substernal goiter (arrow) displacing and compressing trachea and esophagus.
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likely that with increased availability, CT scanning of the mediastinum will supplant radioisotope study, even in the patient in whom substernal goiter is suspected. Other forms of evaluation may occasionally be employed. Elhence and associates [72] described the use of thyroid lymphography in patients with thyroid disorders, including substernal goiter. A patient in whom superior vena caval syndrome is clinically suspected can be evaluated by radionuclide venacavography [59] or by venography [60].
Needle Biopsy Needle biopsy of cervical thyroid nodules has been proven safe and effective [73, 741. Similar biopsy of intrathoracic goiters has been successful in some instances [75] but unsuccessful in others [44]. In addition, substernal goiters present the potential for poorly controlled bleeding and subsequent airway embarrassment, thus increasing the risk of an otherwise benign procedure. The indications for resection of a substernal goiter chiefly involve the necessity to relieve the mechanical rather than the cytopathologicaleffects. If need be, however, the palpable cervical portion of the thyroid mass can be safely biopsied.
Treatment of Substernal Goiter Nonoperative Therapy In 1939, Crile [13] stated that “the treatment of intrathoracic goiter is surgical,” but he suggested that asymptomatic patients more than 65 years of age, in whom life expectancy was shortened by arteriosclerosis or hypertension, might be followed without surgical intervention. Since that time, life-expectancy has increased and surgical risks have become negligible, yet in 1955, Ehrenhaft and Buckwalter [39]estimated that up to half of all patients with substernal goiter were not referred for operation. Medical treatment in the past included radiotherapy [76] but more recently has involved the use of 1311, propylthiouracil, or levothyroxine. There is little evidence that such agents are effective in relieving mechanical symptoms or even in halting progressive growth. Radioactive iodine treatment may be appropriate for the rare hyperfunctioning nodule in a substernal goiter [66] but is less successful for the more common diffuse goiter. Long-standing multinodular goiters, whether cervical or substernal, generally respond poorly to prolonged thyroid suppression [77, 781. In a 1966 report of 600 patients at the Massachusetts General Hospital, Welch [79] cited the poor response of multinodular goiter to such therapy; a recent report from the same institution [26] relating specifically to substernal goiter indicated that symptoms and signs remained the same or progressed despite documented suppression of thyroid-stimdating hormone by levothyroxine administration prior to referral for operation. Therefore, nonoperative treatment of substernal goiter should be reserved for the pa-
tient who presents an exceptionally high operative risk or who has refused operation.
Operation The presence of a substernal goiter in all but the highestrisk patients is an indication for resection. Asymptomatic patients will benefit from elimination of the small but present risk of acute stridor or occult thyroid malignancy, and the symptomatic patients will be relieved of dyspnea and dysphagia. Reeve and associates [ZO], for example, showed that both vital capacity and maximum breathing capacity were markedly greater postoperatively in a group of 21 patients undergoing resection of intrathoracic goiter. The most common operative approach is through the standard cervical collar incision. With rare exceptions, substernal goiters receive blood supply from cervical thyroid vessels and maintain some connection to the thyroid gland in the neck; the substernal mass itself can usually be delivered into the neck without widening the thoracic inlet. Clute and Lawrence [33] stated that they had “never had occasion to enlarge the bony thoracic strait for the removal of a substernal goiter” and Crile [13] split the sternum in only 1of 97 patients. In a review of the Mayo Clinic experience, Judd and colleagues [30] noted that even large substernal goiters could be removed by the standard cervical approach and with less morbidity than by sternotomy or thoracotomyconclusions that were mirrored by Reeve’s group [ZO]. Many authors recommend the cervical approach as the primary one for resection of substernal goiters [12, 26, 27, 32, 481. A number of surgeons disagree with this approach, however. Ehrenhaft and Buckwalter [39] believed that removal by the cervical approach alone was not indicated as this approach increased the risk of uncontrollable hemorrhage, injury to the recurrent laryngeal nerves, and incomplete removal of the goiter; they favored sternotomy for anterior mediastinal goiters or right lateral thoracotomy for posterior goiters. Sherman and Shahbahrami [42] favored full sternotomy, with thoracotomy reserved for large posterior goiters, and Gourin and co-workers [28] used a collar incision supplemented by partial upper sternotomy in every patient. Falor and associates [18, 451 thought it would have been impossible to remove any of their 7 ”primary intrathoracic goiters” (i.e., those with an intrathoracic blood supply) through a cervical incision, and they performed right thoracotomy with or without cervical resection at a second operation. In the past, some surgeons made no deliberate attempt to identify the recurrent laryngeal nerve [33, 391, although more recent reports recommend a search for this nerve [15, 20, 26, 321. Similarly, the parathyroid glands have been routinely sought by some [15,26] but not all surgeons [39]. Even large substernal goiters can usually be delivered from the mediastinum by means of subcapsular dissection, traction, a sweeping motion of the surgeon’s
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Collective Review: Katlic, Wang, and Grillo: Substernal Goiter
finger, patience, and, occasionally, sponge-holding clamps or other instruments. Kocher [9] made use of special forceps or spoons for extracting such goiters, but Keynes [SO] said that he ”would deprecate the use of any special or homely instrument for this purpose. . . . Guile is better.” The technique of morcellation or fragmentation of the substernal mass, as popularized by Lahey [31] was reported to be used in an occasional patient by some surgeons [15,18,32]. Others believed that this technique could lead to increased bleeding and theoretically would be disadvantageous in the presence of an occult malignancy [26, 27, SO]. Extraction of goiters located in the posterior mediastinum may prove more difficult. In the past, surgeons recommended a combined cervical/thoracic or cervical/ sternotomy approach to these goiters [47, 81, 821. Mora and colleagues [83] recommended routine morcellation in such situations. DeAndrade [32], however, reported that in his 40-year experience in Brazil, it was possible to remove 122 of 128 posterior mediastinal goiters through a cervical approach alone. Intraoperative or postoperative problems with the trachea, such as tracheomalacia or tracheal ”collapse,” have been alluded to throughout the history of goiter surgery and have led one author [87] to recommend routine postoperative tracheostomy. Crile [13] thought that such collapse never occurred except as a manifestation of bilateral vocal cord palsy. Since that time, though, there have been a number of reports of tracheomalacia following resection of cervical or substernal goiter. These patients have variously been treated by prolonged intubation or temporary tracheostomy [30, 511, circumferential application of Marlex mesh around the trachea [85, 861, suturing the trachea to the soft tissues of the neck [87-891, or buttressing the trachea with plastic rings 1901. Green and colleagues [29] summarized the literature on this subject in 1979. The most reasonable course on recognition of tracheomalacia is endotracheal intubation for 24 to 48 hours or longer if necessary; tracheostomy or tracheal T-tube placement can be performed on the rare patient in whom the problem persists.
Postoperative Mortality and Morbidity Data relating to deaths from untreated substernal goiter are unavailable. Postoperative deaths are extremely rare (many large series report none or, at most, 1 such death) and are generally due to cardiac causes or pulmonary embolism. In past decades, major postoperative complications such as bleeding, pneumonia, or recurrent laryngeal nerve palsy occurred occasionally, but at present these are quite rare. Minor complications may be seen in an occasional patient; these include transient recurrent nerve palsy, transient hypocalcemia, atelectasis, and wound seroma. Results of Operation Patients should be relieved of upper respiratory and esophageal obstruction by resection of substernal goiter.
Those with occult carcinoma are likely to be cured. Most patients will be able to leave the hospital in three to seven days. These patients should be examined for possible recurrence of goiter over the ensuing years, however; nearly every series of substernal goiters includes a proportion of patients-as high as 20 to 25% in some series [15,26,33,39,44]-who were seen with recurrent substernal goiter. Although many surgeons place patients on levothyroxine indefinitely after operation, it may be unnecessary [50] and there is little evidence that it will prevent recurrence.
References 1. Halsted WS: The operative story of goitre. Johns Hopkins Hosp Rep 19:71, 1920 2. Gunther GB: Operativ Behandlung des Kropfes (struma). In Lehre von den blutigen Operaconen am menschlichen Korper. Leipzig, 1864, p 369 3. Haller A: Disputationes Anatomicae Selectae. Gottingen, Vandenhoeck, 1749, p 96 4. Klein: Ueber die Austrottung verschiedener geschwiilste, besonders jener der Ohrspercheldruse und der 5. 6. 7. 8.
9. 10. 11. 12.
Schilddriise; Aussachalung der Schilddriise. J Chir AugenHeilk 120:106, 1820 Hedenus JAW: Austrottung der Schilddriise. J Chir AugenHeilk 121237, 1821 Gross SD. A System of Surgery. Fourth edition. Philadelphia, Lea, 1866, p 394 Billroth T: Geschwulste der Schilddruse. Chir Klin Zuruch, p 167, 1869 Kocher T: Bericht uber weitere 250 Kropfexstirpationen. Corresp Schweiz Aztle 19:1, 1889 Kocher T: Bericht uber ein zweites tousend Kropfexcisionen. Arch Klin Chir M454, 1901 Mikulicz J: Beitrag zur Operation des Kropfes. Wien Med Wochenschr, p 1, 1886 Lahey FH: Diagnosis and management of intrathoracic goiters. JAMA 75:163, 1920 Lindskog GE, Goldenberg IS: Differential diagnosis, pathology and treatment of substernal goiter. JAMA
163:327, 1957 13. Crile G Jr: Intrathoracic goiter. Cleve Clin Q 6:313, 1939 14. DeCourcy JL, Price CA: Intrathoracic goiter. Am J Surg 64257, 1944 15. JohnstonJH, Twente GE: Surgical approach to intrathoracic (mediastinal) goiter. Ann Surg 143:572, 1956 16. Wakeley CPG, Mulvany JH: Intrathoracic goiter. Surg Gynecol Obstet 70:702, 1940 17. Rives J D Mediastinal aberrant goiter. Ann Surg 126:797, 1947 18. Falor WH, Kelly TR, Krabill WS: Intrathoracic goiter. Ann Surg 142238, 1955 19. Reeve TS, Rubenstein C, Rundle FF: Intrathoracic goitre: its prevalence in Sydney metropolitan mass x-ray surveys. Med J Aust 2949, 1957 20. Reeve TS, Rundle FF, Hales IB, et al: The investigation and management of intrathoracic goiter. Surg Gynecol Obstet 115:223, 1962 21. Wychulis AR, Payne WS, Clagett OT, Woolner LB: Surgical treatment of mediastinal tumors: a 40-year experience. J Thorac Cardiovasc Surg 62:379, 1971 22. Lahey FH, Swinton N W lntrathoracic goiter. Surg Gynecol Obstet 59:627, 1934
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23. Higgins CC: Intrathoracic goiter. Arch Surg 152395, 1927 24. McCort JL: Intrathoracic goiter: its incidence, symptomatology, and roentgen diagnosis. Radiology 53:227, 1949 25. Pemberton J: Surgery of substernal and intrathoracic goiters. Arch Surg 2:1, 1921 26. Katlic MR, Grillo HC, Wang CA: Substernal goiter: analysis of eighty Massachusetts General Hospital cases. Am J Surg (in press, 1985) 27. Georgiadis N, Katsas A, Leoutsakos B: Substernal goiter. Int Surg 54:116, 1970 28. Gourin A, Garzon AA, Karlson KE: The cervicomediastinal approach to intrathoracic goiter. Surgery 69:651, 1971 29. Green WER, Shepperd HWH, Stevenson HM, Wilson W: Tracheal collapse after thyroidectomy. Br J Surg 66:554, 1979 30. Judd ES, Beahrs OH, Bowes DE: A consideration of the proper surgical approach for substernal goiter. Surg Gynecol Obstet 110:90, 1960 31. Lahey FH: Intrathoracic goiters. Surg Clin North Am 25:609, 1945 32. DeAndrade MA: A review of 128 cases of posterior mediastinal goiter. World J Surg 1:789, 1977 33. Clute HM, Lawrence KB: Intrathoracic goiter. Am J Surg 54:151, 1941 34. Case Records of the Massachusetts General Hospital: case 22352. N Engl J Med 215:403, 1936 35. Miller RB: Large intrathoracic thyroid. Am J Roentgen01 40:66, 1938 36. Soley MH, Rinehart JF: Intrathoracic goiter simulating right sided cardiac enlargement. Am Heart J 18237, 1939 37. Fish J, Moore RM: Ectopic thyroid tissue and ectopic thyroid carcinoma: a review of the literature and report of a case. Ann Surg 157212, 1963 38. Dundas P: Intrathoracic aberrant goiter. Acta Chir Scand 128729, 1964 39. Ehrenhaft JL, Buckwalter JA: Mediastinal tumors of thyroid origin. Arch Surg 7 1 3 7 , 1955 40. Nwafo DC: Heterotopic mediastinal goitre. Br J Surg 65:505, 1978 41. Salomon J, Levy MJ: Mediastinal aberrant goiter: report of two cases. Dis Chest 52413, 1967 42. Sherman CH, Shahbahrami F: Mediastinal goiters: review of ten cases. Am Surg 32:137, 1966 43. Ziter FMH: Ectopic mediastinal thyroid. Dis Chest 49:641, 1966 44. Rietz KA, Werner 8: Intrathoracic goiter. Acta Chir Scand 119:379, 1960 45. Falor WH, Kelly TR, Jackson J R Intrathoracic goiter. Surg Gynecol Obstet 117604, 1963 46. Bashist B, Ellis K, Gold RP: Computed tomography of intrathoracic goiters. AJR 140:455, 1983 47. Sweet RH: Intrathoracic goiter located in the posterior mediastinum. Surg Gynecol Obstet 89:57, 1949 48. Lamke LO, Bergdahl L, Lamke 8: Intrathoracic goitre: a review of 29 cases. Acta Chir Scand 145:83, 1979 49. Aasted A, Bertelsen S: Superior vena caval syndrome in benign mediastinal goitre. Acta Chir Scand 147405, 1981 50. Watt-Boolsen S, Blichert-Toft M, Folke K, et al: Surgical treatment of benign nontoxic intrathoracic goiter: a longterm observation. Am J Surg 141:721, 1981 51. Alfonso A, Christoudias G, Amaruddin Q, et al: Tracheal or esophageal compression due to benign thyroid disease. Am J Surg 142350, 1981 52. Ellis FH, Good CA, Seybold WD: Intrathoracic goiter. Ann Surg 135:79, 1952
53. Torres A, Arroyo J, Kastanos N, et al: Acute respiratory failure and tracheal obstruction in patients with intrathoracic goiter. Crit Care Med 11:265, 1983 54. Lesoin F, Bousquet C, Thomas CE, et al: Transient ischemic attacks in patient with endothoracic goitre and congenital anomaly of the carotid artery. Lancet 2:98, 1982 55. Gomes MN, Hufnagel CA: Superior vena cava obstruction: a review of the literature and report of 2 cases due to benign intrathoracic tumors. Ann Thorac Surg 20:344, 1975 56. Fragomeni LS, Deazambuja PC: Intrathoracic goitre in the posterior mediastinum. Thorax 35:638, 1980 57. Lesavoy MA, Norberg HI', Kaplan EL: Substernal goiter with superior vena caval obstruction. Surgery 77325, 1975 58. Mahajan V, Strimlan V, Van Ordstrand HS, Loop FD: Benign superior vena cava syndrome. Chest 68:32, 1975 59. Sy WM, Lao RS, Seo IS: Scintigraphic features of superior vena caval obstruction due to substernal nontoxic goitre. Br J Radiol 55:301, 1982 60. Ulreich S, Lowman RM, Stern H: Intrathoracic goitre: a cause of the superior vena cava syndrome. Clin Radiol 28:663, 1977 61. Hershey CO, McVeigh RC, Miller RP: Transient superior vena cava syndrome due to propylthiouracil therapy in intrathoracic goiter. Chest 79:356, 1981 62. Sorokin JJ, Levine SM, Moss EG, Biddle CM: Downhill varices: report of a case 29 years after resection of a substernal thyroid gland. Gastroenterology 73345, 1977 63. Kelly TS, Mayors DJ, Boutsicaris PS: "Downhill" varices: a cause of upper gastrointestinal hemorrhage. Am Surg 48:35, 1982 64. Fleig WE, Stange EF, Ditschuneit H: Upper gastrointestinal hemorrhage from downhill esophageal varices. Dig Dis Sci 2723, 1982 65. Karadeniz A, Hacihanefioglu U: Abscess formation in an intrathoracic goitre. Thorax 37556, 1982 66. Fui SNT, Prior J, Saunders AJ, Maisey MN: Posterior intrathoracic goitre as a cause of thyrotoxicosis. Br J Radiol 52995, 1979 67. Jauregui R, Lilker ES, Bayley A: Upper airway obstruction in euthyroid goiter. JAMA 238:2163, 1977 68. Glazer GM, Axel L, Moss AA: CT diagnosis of mediastinal thyroid. AJR 138:495, 1982 69. Adams HD: Transthoracic thyroidectomy. J Thorac Surg 19:741, 1950 70. Irwin RS, Braman SS, Arvanitidis AN, Hamolsky MW: 131 iodine thyroid scanning in preoperative diagnosis of mediastinal goiter. Ann Intern Med 89:73, 1978 71. Nejatheim M, Strashun A M CT versus iodine scanning in diagnosis of mediastinal thyroid (letter). AJR 1392334, 1982 72. Elhence IF, Trehon OF, Gupta CK, Sikroria S, Sharma BD: Thyroid lymphography. Int Surg 62:583, 1977 73. Wang CA, Vickery AL Jr, Maloof F: Needle biopsy of the thyroid. Surg Gynecol Obstet 143:365, 1976 74. Wang CA, Guyton ST, Vickery AL Jr: A further note on the large needle biopsy of the thyroid gland. Surg Gynecol Obstet 156:509, 1983 75. Mishriki YY, Lane BP, Lozowski MS, Epstein H: Hiirthlecell tumor arising in the mediastinal ectopic thyroid and diagnosed by fine needle aspiration. Acta Cytol (Baltimore) 27:188, 1983 76. Case Records of the Massachusetts General Hospital: case 24191. N Engl J Med 218816, 1938 77. Lindem MD Jr, Clark JH: Indications for surgery in thyroiditis. Am J Surg 118:829, 1969
399 Collective Review: Katlic, Wang, and Grillo: Substemal Goiter
78. Sedgwick CE: Nontoxic nodular goiter. In Surgery of the Thyroid Gland: Major Problems in Clinical Surgery. Philadelphia, Saunders, 1974, pp 121-125 79. Welch CE: Therapy for multinodular goiter. JAMA 195:95, 1966 80. Keynes G: Thyroid surgery 50 years ago, with a contribution on intrathoracic goitre. Br Med J 1:621, 1950 81. Maurer ER: The surgical treatment of retrotracheal intrathoracic goiter. Arch Surg 71:357, 1955 82. Hilton HD, Griffin WT: Posterior mediastinal goiter. Am J Surg 116391, 1968 83. Mora JM, Isaacs HJ, Spencer SH, Edidin L: Posterior mediastinal goiter. Surg Gynecol Obstet 79:314, 1944 84. Dorsey JM, McKinnon A: Surgical management of intrathoracic goiter through the sternum splitting approach. Arch Surg 65:570, 1952 85. Halttunen P, Meurall H, Standertskjold-Nordenstam CG:
86.
87. 88.
89. 90.
New surgical correction of central airway collapse in an asthmatic patient. Scand J Thorac Cardiovasc Surg 15:343, 1981 Meurala H, Halttunen P, Standertskjold-Nordenstam CG, Keskitlo E: Surgical support of collapsing intrathoracic tracheal malacia after thyroidectomy. Acta Chir Scand 148:127, 1982 Henry CKP: Tracheal collapse during thyroidectomy. Curr Res Anaesth Analg 6146, 1927 Peterson MC, Ravenstine EA: Tracheal collapse complicating thyroidectomy: case report. Curr Res Anaesth Analg 15:300, 1936 Dinstl K, Keminger K: Zur operativen Therapie der Tracheomalacie. Acta Chir Austriaca 3:100, 1970 Grillo HC: Benign and malignant diseases of the trachea. In Shields TW (ed): General Thoracic Surgery. Second edition. Philadelphia, Lea & Febiger, 1983, pp 545-560
Notice from the American Board of Thoracic Surgery The American Board of Thoracic Surgery began its recertification process i n 1984. Diplomates interested in participating i n recertification should maintain a documented list of the cardiothoracic operations they performed during the year prior to application for recertification. They should also keep a record of their attendance a t thoracic surgical meetings a n d other continuing education medical activities for the t w o years prior to application for recertification. In place of a cognitive examination, candidates for recertification will be required to complete both the general thoracic a n d cardiac portions of the SESATS I1 Syllabus (Self-Education/Self-Assessment in Thoracic Surgery). It is n o t necessary for candidates to purchase
SESATS I1 prior t o applying for recertification. SESATS I1 booklets will be forwarded to candidates after their applications have been received. Diplomates whose ten-year certificates will expire in 1987 may begin t h e recertification process in 1985. This new certificate will b e dated ten years from the time of expiration of the original certificate. Recertification is also open to any Diplomate with a n unlimited certificate. The deadline for submission of applications for recertification is July 1, 1985. A recertification brochure outlining t h e rules a n d requirements for recertification in thoracic surgery is available on request from the American Board of Thoracic Surgery, 14640 E Seven Mile Rd, Detroit, MI 48205.
Substernal Goiter Mark R. Katlic, M.D., Chiu-an Wang, M.D., and Hermes C. Grillo, M.D. ABSTRACT The literature on substernal goiter from the seventeenth century to the present is reviewed. Substernal goiter may be defined as any thyroid enlargement that has its greater mass inferior to the thoracic inlet. Truly ectopic mediastinal goiters are rare, and most substernal goiters arise from and maintain some attachment to the cervical thyroid gland. Patients are generally in the fifth decade of life, and women predominate. Most patients experience dyspnea, stridor, or dysphagia, but 15 to 50% are asymptomatic; symptoms are often positional, and acute stridor may occur. Ten to twenty percent have no cervical mass or tracheal deviation on examination, and virtually all patients are euthyroid. Standard chest roentgenograms are often diagnostic, but computed tomographic or radioactive iodine scans may be helpful. The presence of a substernal goiter in all but the highest-risk patients is an indication for resection, usually through a cervical collar incision; an occasional patient will require sternotomy or thoracotomy. Death or major complications should be rare postoperatively. Substernal goiters are adenomatous and benign, but carcinoma occurs in 2 to 3% and may be occult. Patients should be followed closely, as these goiters may recur.
The extirpation of the thyroid gland for goitre typifies, perhaps better than any operation, the supreme triumph of the surgeon‘s art. A feat which today can be accomplished by any really competent operator without danger of mishap and which was conceived more than 1000 years ago . . . William Stewart Halsted [l] Substernal goiters share a number of properties with their solely cervical counterparts. They grow slowly over many years, cause few symptoms until they are quite large, are mostly (but not universally) benign, and are readily amenable to operative cure. Extension of a substernal goiter into the unyielding thoracic inlet, however, greatly amplifies the mechanical effect of the mass and threatens the patient’s life. Dyspnea and dysphagia are more likely, risks of acute asphyxiation or superior vena caval syndrome are increased, and diagnosis and resection become more difficult. Many of the world’s most influential surgeons, including Billroth, Kocher, Halsted, and Gross, have written about substernal goiters, and the last 50 years have seen
From the General Thoracic Surgical Unit and the General Surgical Services, Massachusetts General Hospital, and the Department of Surgery, Harvard Medical School, Boston, MA. Address reprint requests to Dr. Katlic, 35 W Linden St, Wilkes-Barre, PA 18702.
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a profusion of articles on various aspects of this condition. The present review was undertaken to relate those chapters in the colorful history of goiter surgery that pertain to the substernal group, and to s ~ - i m a r i zand e bring perspective to the current wealth c material on these goiters.
Historical Background Surgeons have been heroically removing goiters since the sixteenth century-perhaps as early as 900 A.D. [1]but these have been isolated instances with disastrous results that were usually due to unremitting hemorrhage. In 1864, Gunther [2] described a case from 1770 in which ”after several fruitless attempts at ligation of the arteries, the severe hemorrhage was controlled by compression day and night during eight days by persons alternating with each other at the task.” He listed a total of 41 operations for struma lymphatica, the common goiter, reported in the literature through 1861. Substernal goiter had been described anatomically in 1749 by Haller [3] but probably the first written account in which an extirpated goiter was clearly beneath the sternum was that of Klein [4] in 1820. The next year Hedenus [5] reported removal, without a death, of 6 goiters causing suffocation. This feat was performed without benefit of hemostatic clamps or anesthesia, and Hedenus’s record was unmatched for the remainder of the century. As late as 1866, Gross [6] wrote in A System Of Surgery:
“10 sensible man will, on slight consideration, attempt to extirpate a goitrous thyroid gland. If a surgeon should be so adventurous or foolhardy as to undertake the enterprise, I shall not envy him his feelings while engaged in the performance of it, or after he has completed it, should he be so fortunate as to do this. Every step he takes will be environed with difficulty, every stroke of his knife will be followed by a torrent of blood and lucky will it be for him if his victim live long enough to enable him to finish his horrid butchery. During this time Billroth had performed 20 such operations with 8 deaths in Zurich. At least 1 of these goiters was substernal, for he noted that ”the trachea, especially at its entrance into the chest, was compressed by many nodules in the thyroid gland” [7]; this patient died 48 hours after total thyroidectomy. Billroth‘s next 48 cases of goiter, in the period from 1877 to 1881 and after introduction of antiseptic principles, resulted in only 4 deaths. These numbers are virtually identical to Halsted’s experience in the United States up to 1883 [l]. It was Kocher, however, who utilized sound principles of anesthesia, hemostasis, and antisepsis to show that goiter surgery could be made reproducibly safe; his work influenced European disciples as well as Halsted. The mortality for his series of 225 patients with benign
392 The Annals of Thoracic Surgery Vol 39 No 4 April 1985
A
B
Fig 1. (A, B ) Max Brodel illustrations from “The Operative Story of Goitre” by Halsted [I]. (Reproduced with permission of the Johns Hopkins University Press.)
brisk hemorrhage and infection but safe, anatomical dissection and grateful patients. As Halsted [l]noted, ”In the story of the development of the operation for goitre the essential history of surgery is comprised.”
goiter was 0.8% [8]. Reporting on a second series of 1,000 patients in 1901, in which there were 4 deaths among 929 patients with benign goiter, Kocher [9] wrote of the special problems of intrathoracic goiters. He found hemorrhage to be a great problem in this situation and recommended double ligation of the accessible vessels from above. He constructed special forceps and a spoon for delivering the substernal mass, and he advised fragmenting the tumor if necessary. At the time of his death in 1917, approximately 5,000 goiters had been removed at Kocher’s clinic [l]. Another great influence on Halsted, and hence on American surgery, was Mikulicz [lo]. By 1886, this careful surgeon had removed 25 goiters without a death. That same year, he performed an operation he termed ”resection” rather than ”extirpation,” in which he removed the entire left thyroid lobe and part of the substernal right lobe. Halsteds 1920 monograph [l],with its critical analysis of 375 articles and the unsurpassed Max Brodel illustrations of technique (Fig l), remains the landmark work on the history of goiter surgery. Also in 1920, Lahey [ l l ] manifested his early interest in the thyroid gland with his first published paper, “Diagnosis and Management of Intrathoracic Goiters.” The turning point in goiter surgery occurred in the last part of the nineteenth century. Before this time, patients sitting upright in chairs underwent painful extirpation without anesthesia and often died of hemorrhage or sepsis. With the introduction of anesthesia, principles of hemostasis, and antisepsis came dramatic improvements in results that led surgeons to expect not
Characteristics of Substernal Goiter Definition Substernal goiter may be defined as any thyroid enlargement that has its greater mass inferior to the thoracic inlet. This condition has also been called retrosternal, subclavicular, intrathoracic, mediastinal, aberrant, or wandering goiter; spring goiter; goiter mobile; and goiter plongeant. Various criteria have been proposed for including goiters in the substernal group. Lindskog and Goldenberg [12] termed a goiter substernal or mediastinal if its lower border was found radiographically to reach the level of the transverse process of the fourth thoracic vertebra or lower. Crile [13] considered a goiter truly intrathoracic only if it extended downward as far as the arch of the aorta. Other authors [14-161 have considered a goiter partially intrathoracic when its greater mass was inferior to the thoracic inlet and totally intrathoracic when its entire mass was inferior to the thoracic inlet. A further subdivision of the totally intrathoracic group comprises goiters that Rives [17] termed mediastinal aberrant and Falor and colleagues [18] called primary intrathoracic. These are totally intrathoracic goiters that have a blood supply derived from intrathoracic arteries, that drain into intrathoracic veins and that maintain little or no connection to the cervical thyroid gland; they are quite rare. It seems reasonable to call a goiter substernal or intrathoracic if 50 to 100% of its mass lies inferior to the thoracic inlet; the term aberrant should be reserved for goiters that neither receive a cervical blood supply nor maintain any connection to the cervical gland.
393 Collective Review: Katlic, Wang, and Grillo: Substernal Goiter
lncidence Reeve and co-workers [19, 201 found on the basis of mass roentgenographic surveys of the general population of Sydney, Australia, that the incidence of substernal goiter was 1 in 5,040; among women more than 45 years old, it was 1 in 2,030. Intrathoracic goiters comprised 5.3% of 1,064 mediastinal tumors reported by Wychulis and associates [21]. Most authors, however, describe the incidence of substernal goiter in reference to the total number of thyroidectomies performed. Reported incidences of substernal goiter in relation to the total number of patients undergoing thyroidectomy vary according to definition, but range from less than 1% [13] to more than 20% [22]. Goiters that reside completely within the thorax comprise less than 1%of all goiters removed surgically [14, 16,23-251. In 2 to 14% of patients undergoing thyroid surgical procedures, the bulk of the goitrous mass is in the chest [16, 24,26-301. Etiology Two possibilities exist for the presence of this thyroid neoplasm in an abnormal location: (1) the goiter arises from the cervical thyroid tissue and grows inferiorly through the thoracic inlet, and (2) the growth arises from aberrant thyroid tissue already situated in the mediastinum. Although most authors agree that both concepts are theoretically possible, some argue more or less strongly about the existence of such aberrant thyroid tissue. Certainly the vast majority of substernal goiters arise from the cervical thyroid gland, descending along a fascia1 plane into the superior mediastinum. Lahey [31], claiming that each of the 24,000 goiters he had seen arose in the neck, called this a "space with no bottom"; cervical adenomas were directed into this superior mediastinal space by the swallowing mechanism. Many authors found that every substernal goiter they removed maintained some connection to the cervical gland [13, 15, 16, 24, 27, 32, 331 and generally received blood supply from the cervical thyroid vessels. Three cases have been reported of large substernal goiters that descended to touch the diaphragm [34-361, yet even these maintained a pedicle connection to the cervical gland. For a substernal or intrathoracic goiter to have arisen from aberrant thyroid tissue in the mediastinum, its blood supply should be from thoracic vessels and it should maintain no connection to the cervical gland. Ectopic thyroid tissue has been found from the tongue to the diaphragm [37], presumably carried there during embryological development of the thyroid and thymus. In a review in 1947, Rives [17] found 14 unquestionable cases of aberrant mediastinal goiters and added 3 cases of his own. Since that time, many authors have reported 1 or 2 individual cases that could be considered truly aberrant [14, 18, 38-45]. The blood supply in these goiters arose from the aorta, subclavian artery, internal mammary arteries, thyrocervical trunk, or innominate artery. The venous drainage was generally into corresponding thoracic veins. Occasionally, however, even
cervical goiters may receive some blood supply from thoracic vessels [15, 421. The presence or absence of a fibrous connection to the cervical gland seems less important; a band of tissue might exist regardless of embryological versus adult migration of the aberrant tissue. To all intents and purposes, then, substernal goiters arise from and maintain some attachment to the cervical thyroid gland. Mediastinal goiters arising from truly ectopic thyroid tissue exist but are extremely rare.
Location Substernal goiters arise equally from the right and left lobes of the thyroid gland [12, 24, 26, 281, although in an occasional series [23], right-sided goiters predominate. DeAndrade [32]pointed out that some goiters arise from the left thyroid lobe but grow into the right mediastinum because of the presence of the aortic arch. Most substernal goiters reside in the anterolateral mediastinum; few are limited to the true anterior pretracheal space [46]. In 1949, Sweet [47] drew attention to those goiters limited to the posterior mediastinum, and subsequent reports [24, 26, 271 showed that goiters in this position comprise 10 to 15%of all substernal goiters. Sweet believed that these posterior descending goiters arose not from the inferior pole of the lateral thyroid lobe but from its posterior and lateral aspect. The largest experience with goiters in the posterior mediastinum is that of DeAndrade with 128 cases [32]. Age and Sex Distribution Substernal goiters are most common in patients in the fifth decade of life [12, 13,22, 26, 28,42,47, 481. Pemberton [25] reported the youngest patient with substernal goiter (15 years old). Other authors [49, 501 reported patients more than 80 years of age. Female patients predominate, and the female :male ratio may be as high as 9: 1 (161, although it is typically 3 or 4: 1 [27, 28, 32, 391. In a few series, there were equal numbers of men and women [12, 24,441 and in one [48], a slight predominance of male patients. Symptoms The most common symptoms associated with substernal goiter are dyspnea, stridor, dysphagia, hoarseness, cough, wheeze, and the presence of a bothersome cervical mass. These symptoms do not differ greatly from those of patients with cervical goiters [51] but may be more severe because of the presence of the mass within the bony thoracic inlet. Most investigators agree that respiratory symptoms predominate, although dysphagia may occur in up to one-third of patients [12, 16, 261. Fifteen to 50% of patients have no symptoms whatsoever [12, 13, 24, 26, 39, 48, 521. In 1921, Pemberton [25] drew attention to the positional nature of these symptoms in some patients, and his findings have been reproduced in most subsequent series. A subset of patients will complain of dyspnea, stridor, or facial flushing only when they are supine, when their arms are raised or their neck is extended, or
394 The Annals of Thoracic Surgery Vol 39 No 4 April 1985
when they are looking to the right or the left; these symptoms result from the goitrous mass being drawn into the thoracic inlet. A smaller group of patients (2 to 3%)will experience the acute onset of stridor [16, 20, 26, 27, 30,44, 501. This may be due to incarceration of the mass in the thoracic inlet or to the occurrence of hemorrhage either spontaneously [51] or after trauma [27]. Acute stridor may be life-threatening in this situation, as neither endotracheal intubation nor tracheostomy relieves the obstruction in every instance [53]. Central nervous system symptoms due to carotid artery compression are extremely rare. Lesoin and colleagues [54] reported the case of a patient with a congenital anomaly of the carotid arteries and compression by a substernal goiter; the patient’s frequent transient ischemic attacks with left hemiparesis were cured by thyroidectomy. Lamke and associates [48] described cerebral edema and a large substernal goiter compressing the right carotid artery in a patient who died on induction of anesthesia.
Signs Physical findings in patients with substernal goiter include cervical mass, tracheal deviation, hoarseness, obesity, and dilated veins. Most patients have a goitrous mass palpable in the neck, but 10 to 20%have no cervical abnormality [12, 26, 30, 39, 42, 521. In other patients, the mass may be evanescent, appearing when the arms are elevated, when the patient is supine, or with coughing or swallowing [26, 521. Clute and Lawrence [33] pointed out that inability of the examining physician to palpate the lower thyroid pole was a clue that substernal extension of the goiter might exist. Dilated veins and facial flushing may also be positional. Most cases of true superior vena caval obstruction are due to malignancy [55], but a rare case is the result of substernal goiter [15, 49, 55-61]. Superior vena caval obstruction by an intrathoracic goiter may also result in so-called downhill esophageal varices [62-641. These varices may serve as collaterals either to bypass superior vena caval obstruction through the azygos vein or to drain systemic blood from the head and neck to the portal vein when both the superior vena cava and the azygos system are occluded. Such patients may show signs of gastrointestinal bleeding in the absence of the stigmata of portal hypertension. Pain or tenderness associated with substernal goiter is rare and may indicate thyroid malignancy or, in one reported instance [65], abscess formation. Pathological Characteristics Substernal goiters are adenomatous by nature, being multinodular or composed of one or more follicular adenomas [12, 13, 27, 30, 31, 39, 521. Hashimoto’s thyroiditis may occur [26]. Old hemorrhage, calcification, cyst formation, fibrosis, and focal thyroiditis are occasionally noted. Diameter of the goiter may range from 4 to 18 or 19 cm, but the average is about 6 to 10 cm. Goiter
weights range from 25 to more than 1,000 gr [52]; the average reported weight is from 100 to 200 gr. Carcinoma occurs in 2 to 3% of substernal goiters [16, 261. Many authors have reported 1 or 2 patients with carcinoma [12, 24, 25, 27, 30, 32, 481, and in several of these patients, the carcinoma was occult [20, 261. The fact that these carcinomas can grow considerably with no marked change in patient symptoms or signs argues for removal of all substernal goiters.
Diagnosis of Substernal Goiter Laboratory Findings In 1939, Crile [13] reported that 50% of his substernal goiter patients were clinically hyperthyroid, although he admitted that in some instances it might be difficult to determine whether dyspnea in these patients resulted from mechanical or metabolic effects of the goiter. In the 1950s, McCort [24] and Ellis and colleagues [52] found that fewer than 10 to 15% of substernal goiter patients had documented elevations in basal metabolic rate. In more recent series [27,44, 661, only an occasional patient has been found to have thyrotoxicosis. Two groups of investigators [26, 481 have measured thyroid function test results in substernal goiter patients. Lamke and co-workers [48] found that 3 of 29 patients were hyperthyroid on the basis of laboratory testing of thyroid function. Katlic and associates [26] reported preoperative thyroid function testing in 52 of 80 substernal goiter patients; 51 were euthyroid and 1, who had had prior neck radiotherapy, was mildly hypothyroid. Pulmonary function evaluation such as spirometry or flow-volume loop testing will usually show evidence of tracheal obstruction [36, 481. Reeve and colleagues [20] noted abnormally low vital capacities in nearly all of the 27 substernal goiter patients they tested. Even asymptomatic patients who have only cervical goiter are likely to show upper airway obstruction on flow-volume loop testing [67]. Radiographic Findings Patients with substernal goiter may be studied by routine chest roentgenography, linear tomography, computed tomography (CT), barium swallow esophagography, or radioisotope scanning using iodine or technetium. Most authors believe that the standard chest roentgenogram is the most useful radiographic study in terms of cost versus benefit, and some [26, 391 think that it is the only study required for the routine diagnosis of substernal goiter. McCort [24] listed the important roentgenographic findings as follows: displacement of the trachea by the mass; displacement of the trachea beginning high in the neck, frequently at the larynx, with some tilting of the larynx; compression of the trachea; calcification within the goiter; a smooth or only slightly nodular outline of the tumor; and reflection of the mediastinal pleura below the goiter. The addition of fluoroscopy helps determine whether the mass moves
395 Collective Review: Katlic, Wang, and Grillo: Substernal Goiter
A
Fig 2. Linear tomograrns of posterior mediastinal goiter displacing and compressing trachea ( A ) laterally and ( B ) anteriorly.
with swallowing; the goiter moved with deglutition in 84% of McCort’s patients. The presence of calcification does not exclude malignancy, as the single carcinomatous goiter in this series was heavily calcified [24]. Linear tomography accentuates the findings of the plain chest roentgenogram (Fig 2), but for complete evaluation of the mediastinum, CT is unsurpassed (Fig 3). Bashist and co-workers [46] and Glazer and associates [68] recently described the CT findings in representative cases of intrathoracic goiter as follows: continuity of the mediastinal mass with the cervical thyroid; well-defined borders; focal punctate, coarse, or ringlike calcifications; nonhomogeneity, with particular nonenhancing low-density areas; relatively high precontrast attenuation numbers compared with adjacent muscles; enhancement after administration of iodinated contrast material; prolonged enhancement after contrast material administration; and characteristic patterns of extension of goiter into the mediastinum. In 1950, Adams [69] stressed the importance of routine barium swallow esophagography in the evaluation of mediastinal masses. Clute and Lawrence [33] believed that the substernal goiter rarely affects the course of the esophagus, but others (24, 261 found esophageal deviation or compression in up to one-third of patients. Alfonso and co-workers [51] reported compression of the cervical esophagus in 53 of 273 patients with benign cervical goiters alone. Rietz and Werner [44] observed that
B
in all of their 12 patients with posterior goiter, the esophagus was displaced. The role of radioisotope scanning of the thyroid in these patients is controversial. Irwin and colleagues [70] found that preoperative iodine 131 scanning was diagnostic in all of their 27 patients with documented substernal goiter. Others [46, 681 found I3’I scanning less useful in that a negative scan could occur in the presence of substernal goiter because there is little or no functioning thyroid tissue in the substernal component. Nejatheim and Strashun [71] pointed out that if 13’1 scanning is to be performed, it must precede contrast CT evaluation, since expansion of the body pool of iodine by contrast infusion interferes with normal thyroid uptake of the scanning dose of radioactive iodine. It seems
Fig 3. Computed tornogram of substernal goiter (arrow) displacing and compressing trachea and esophagus.
396 The Annals of Thoracic Surgery Vol 39 No 4 April 1985
likely that with increased availability, CT scanning of the mediastinum will supplant radioisotope study, even in the patient in whom substernal goiter is suspected. Other forms of evaluation may occasionally be employed. Elhence and associates [72] described the use of thyroid lymphography in patients with thyroid disorders, including substernal goiter. A patient in whom superior vena caval syndrome is clinically suspected can be evaluated by radionuclide venacavography [59] or by venography [60].
Needle Biopsy Needle biopsy of cervical thyroid nodules has been proven safe and effective [73, 741. Similar biopsy of intrathoracic goiters has been successful in some instances [75] but unsuccessful in others [44]. In addition, substernal goiters present the potential for poorly controlled bleeding and subsequent airway embarrassment, thus increasing the risk of an otherwise benign procedure. The indications for resection of a substernal goiter chiefly involve the necessity to relieve the mechanical rather than the cytopathologicaleffects. If need be, however, the palpable cervical portion of the thyroid mass can be safely biopsied.
Treatment of Substernal Goiter Nonoperative Therapy In 1939, Crile [13] stated that “the treatment of intrathoracic goiter is surgical,” but he suggested that asymptomatic patients more than 65 years of age, in whom life expectancy was shortened by arteriosclerosis or hypertension, might be followed without surgical intervention. Since that time, life-expectancy has increased and surgical risks have become negligible, yet in 1955, Ehrenhaft and Buckwalter [39]estimated that up to half of all patients with substernal goiter were not referred for operation. Medical treatment in the past included radiotherapy [76] but more recently has involved the use of 1311, propylthiouracil, or levothyroxine. There is little evidence that such agents are effective in relieving mechanical symptoms or even in halting progressive growth. Radioactive iodine treatment may be appropriate for the rare hyperfunctioning nodule in a substernal goiter [66] but is less successful for the more common diffuse goiter. Long-standing multinodular goiters, whether cervical or substernal, generally respond poorly to prolonged thyroid suppression [77, 781. In a 1966 report of 600 patients at the Massachusetts General Hospital, Welch [79] cited the poor response of multinodular goiter to such therapy; a recent report from the same institution [26] relating specifically to substernal goiter indicated that symptoms and signs remained the same or progressed despite documented suppression of thyroid-stimdating hormone by levothyroxine administration prior to referral for operation. Therefore, nonoperative treatment of substernal goiter should be reserved for the pa-
tient who presents an exceptionally high operative risk or who has refused operation.
Operation The presence of a substernal goiter in all but the highestrisk patients is an indication for resection. Asymptomatic patients will benefit from elimination of the small but present risk of acute stridor or occult thyroid malignancy, and the symptomatic patients will be relieved of dyspnea and dysphagia. Reeve and associates [ZO], for example, showed that both vital capacity and maximum breathing capacity were markedly greater postoperatively in a group of 21 patients undergoing resection of intrathoracic goiter. The most common operative approach is through the standard cervical collar incision. With rare exceptions, substernal goiters receive blood supply from cervical thyroid vessels and maintain some connection to the thyroid gland in the neck; the substernal mass itself can usually be delivered into the neck without widening the thoracic inlet. Clute and Lawrence [33] stated that they had “never had occasion to enlarge the bony thoracic strait for the removal of a substernal goiter” and Crile [13] split the sternum in only 1of 97 patients. In a review of the Mayo Clinic experience, Judd and colleagues [30] noted that even large substernal goiters could be removed by the standard cervical approach and with less morbidity than by sternotomy or thoracotomyconclusions that were mirrored by Reeve’s group [ZO]. Many authors recommend the cervical approach as the primary one for resection of substernal goiters [12, 26, 27, 32, 481. A number of surgeons disagree with this approach, however. Ehrenhaft and Buckwalter [39] believed that removal by the cervical approach alone was not indicated as this approach increased the risk of uncontrollable hemorrhage, injury to the recurrent laryngeal nerves, and incomplete removal of the goiter; they favored sternotomy for anterior mediastinal goiters or right lateral thoracotomy for posterior goiters. Sherman and Shahbahrami [42] favored full sternotomy, with thoracotomy reserved for large posterior goiters, and Gourin and co-workers [28] used a collar incision supplemented by partial upper sternotomy in every patient. Falor and associates [18, 451 thought it would have been impossible to remove any of their 7 ”primary intrathoracic goiters” (i.e., those with an intrathoracic blood supply) through a cervical incision, and they performed right thoracotomy with or without cervical resection at a second operation. In the past, some surgeons made no deliberate attempt to identify the recurrent laryngeal nerve [33, 391, although more recent reports recommend a search for this nerve [15, 20, 26, 321. Similarly, the parathyroid glands have been routinely sought by some [15,26] but not all surgeons [39]. Even large substernal goiters can usually be delivered from the mediastinum by means of subcapsular dissection, traction, a sweeping motion of the surgeon’s
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Collective Review: Katlic, Wang, and Grillo: Substernal Goiter
finger, patience, and, occasionally, sponge-holding clamps or other instruments. Kocher [9] made use of special forceps or spoons for extracting such goiters, but Keynes [SO] said that he ”would deprecate the use of any special or homely instrument for this purpose. . . . Guile is better.” The technique of morcellation or fragmentation of the substernal mass, as popularized by Lahey [31] was reported to be used in an occasional patient by some surgeons [15,18,32]. Others believed that this technique could lead to increased bleeding and theoretically would be disadvantageous in the presence of an occult malignancy [26, 27, SO]. Extraction of goiters located in the posterior mediastinum may prove more difficult. In the past, surgeons recommended a combined cervical/thoracic or cervical/ sternotomy approach to these goiters [47, 81, 821. Mora and colleagues [83] recommended routine morcellation in such situations. DeAndrade [32], however, reported that in his 40-year experience in Brazil, it was possible to remove 122 of 128 posterior mediastinal goiters through a cervical approach alone. Intraoperative or postoperative problems with the trachea, such as tracheomalacia or tracheal ”collapse,” have been alluded to throughout the history of goiter surgery and have led one author [87] to recommend routine postoperative tracheostomy. Crile [13] thought that such collapse never occurred except as a manifestation of bilateral vocal cord palsy. Since that time, though, there have been a number of reports of tracheomalacia following resection of cervical or substernal goiter. These patients have variously been treated by prolonged intubation or temporary tracheostomy [30, 511, circumferential application of Marlex mesh around the trachea [85, 861, suturing the trachea to the soft tissues of the neck [87-891, or buttressing the trachea with plastic rings 1901. Green and colleagues [29] summarized the literature on this subject in 1979. The most reasonable course on recognition of tracheomalacia is endotracheal intubation for 24 to 48 hours or longer if necessary; tracheostomy or tracheal T-tube placement can be performed on the rare patient in whom the problem persists.
Postoperative Mortality and Morbidity Data relating to deaths from untreated substernal goiter are unavailable. Postoperative deaths are extremely rare (many large series report none or, at most, 1 such death) and are generally due to cardiac causes or pulmonary embolism. In past decades, major postoperative complications such as bleeding, pneumonia, or recurrent laryngeal nerve palsy occurred occasionally, but at present these are quite rare. Minor complications may be seen in an occasional patient; these include transient recurrent nerve palsy, transient hypocalcemia, atelectasis, and wound seroma. Results of Operation Patients should be relieved of upper respiratory and esophageal obstruction by resection of substernal goiter.
Those with occult carcinoma are likely to be cured. Most patients will be able to leave the hospital in three to seven days. These patients should be examined for possible recurrence of goiter over the ensuing years, however; nearly every series of substernal goiters includes a proportion of patients-as high as 20 to 25% in some series [15,26,33,39,44]-who were seen with recurrent substernal goiter. Although many surgeons place patients on levothyroxine indefinitely after operation, it may be unnecessary [50] and there is little evidence that it will prevent recurrence.
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23. Higgins CC: Intrathoracic goiter. Arch Surg 152395, 1927 24. McCort JL: Intrathoracic goiter: its incidence, symptomatology, and roentgen diagnosis. Radiology 53:227, 1949 25. Pemberton J: Surgery of substernal and intrathoracic goiters. Arch Surg 2:1, 1921 26. Katlic MR, Grillo HC, Wang CA: Substernal goiter: analysis of eighty Massachusetts General Hospital cases. Am J Surg (in press, 1985) 27. Georgiadis N, Katsas A, Leoutsakos B: Substernal goiter. Int Surg 54:116, 1970 28. Gourin A, Garzon AA, Karlson KE: The cervicomediastinal approach to intrathoracic goiter. Surgery 69:651, 1971 29. Green WER, Shepperd HWH, Stevenson HM, Wilson W: Tracheal collapse after thyroidectomy. Br J Surg 66:554, 1979 30. Judd ES, Beahrs OH, Bowes DE: A consideration of the proper surgical approach for substernal goiter. Surg Gynecol Obstet 110:90, 1960 31. Lahey FH: Intrathoracic goiters. Surg Clin North Am 25:609, 1945 32. DeAndrade MA: A review of 128 cases of posterior mediastinal goiter. World J Surg 1:789, 1977 33. Clute HM, Lawrence KB: Intrathoracic goiter. Am J Surg 54:151, 1941 34. Case Records of the Massachusetts General Hospital: case 22352. N Engl J Med 215:403, 1936 35. Miller RB: Large intrathoracic thyroid. Am J Roentgen01 40:66, 1938 36. Soley MH, Rinehart JF: Intrathoracic goiter simulating right sided cardiac enlargement. Am Heart J 18237, 1939 37. Fish J, Moore RM: Ectopic thyroid tissue and ectopic thyroid carcinoma: a review of the literature and report of a case. Ann Surg 157212, 1963 38. Dundas P: Intrathoracic aberrant goiter. Acta Chir Scand 128729, 1964 39. Ehrenhaft JL, Buckwalter JA: Mediastinal tumors of thyroid origin. Arch Surg 7 1 3 7 , 1955 40. Nwafo DC: Heterotopic mediastinal goitre. Br J Surg 65:505, 1978 41. Salomon J, Levy MJ: Mediastinal aberrant goiter: report of two cases. Dis Chest 52413, 1967 42. Sherman CH, Shahbahrami F: Mediastinal goiters: review of ten cases. Am Surg 32:137, 1966 43. Ziter FMH: Ectopic mediastinal thyroid. Dis Chest 49:641, 1966 44. Rietz KA, Werner 8: Intrathoracic goiter. Acta Chir Scand 119:379, 1960 45. Falor WH, Kelly TR, Jackson J R Intrathoracic goiter. Surg Gynecol Obstet 117604, 1963 46. Bashist B, Ellis K, Gold RP: Computed tomography of intrathoracic goiters. AJR 140:455, 1983 47. Sweet RH: Intrathoracic goiter located in the posterior mediastinum. Surg Gynecol Obstet 89:57, 1949 48. Lamke LO, Bergdahl L, Lamke 8: Intrathoracic goitre: a review of 29 cases. Acta Chir Scand 145:83, 1979 49. Aasted A, Bertelsen S: Superior vena caval syndrome in benign mediastinal goitre. Acta Chir Scand 147405, 1981 50. Watt-Boolsen S, Blichert-Toft M, Folke K, et al: Surgical treatment of benign nontoxic intrathoracic goiter: a longterm observation. Am J Surg 141:721, 1981 51. Alfonso A, Christoudias G, Amaruddin Q, et al: Tracheal or esophageal compression due to benign thyroid disease. Am J Surg 142350, 1981 52. Ellis FH, Good CA, Seybold WD: Intrathoracic goiter. Ann Surg 135:79, 1952
53. Torres A, Arroyo J, Kastanos N, et al: Acute respiratory failure and tracheal obstruction in patients with intrathoracic goiter. Crit Care Med 11:265, 1983 54. Lesoin F, Bousquet C, Thomas CE, et al: Transient ischemic attacks in patient with endothoracic goitre and congenital anomaly of the carotid artery. Lancet 2:98, 1982 55. Gomes MN, Hufnagel CA: Superior vena cava obstruction: a review of the literature and report of 2 cases due to benign intrathoracic tumors. Ann Thorac Surg 20:344, 1975 56. Fragomeni LS, Deazambuja PC: Intrathoracic goitre in the posterior mediastinum. Thorax 35:638, 1980 57. Lesavoy MA, Norberg HI', Kaplan EL: Substernal goiter with superior vena caval obstruction. Surgery 77325, 1975 58. Mahajan V, Strimlan V, Van Ordstrand HS, Loop FD: Benign superior vena cava syndrome. Chest 68:32, 1975 59. Sy WM, Lao RS, Seo IS: Scintigraphic features of superior vena caval obstruction due to substernal nontoxic goitre. Br J Radiol 55:301, 1982 60. Ulreich S, Lowman RM, Stern H: Intrathoracic goitre: a cause of the superior vena cava syndrome. Clin Radiol 28:663, 1977 61. Hershey CO, McVeigh RC, Miller RP: Transient superior vena cava syndrome due to propylthiouracil therapy in intrathoracic goiter. Chest 79:356, 1981 62. Sorokin JJ, Levine SM, Moss EG, Biddle CM: Downhill varices: report of a case 29 years after resection of a substernal thyroid gland. Gastroenterology 73345, 1977 63. Kelly TS, Mayors DJ, Boutsicaris PS: "Downhill" varices: a cause of upper gastrointestinal hemorrhage. Am Surg 48:35, 1982 64. Fleig WE, Stange EF, Ditschuneit H: Upper gastrointestinal hemorrhage from downhill esophageal varices. Dig Dis Sci 2723, 1982 65. Karadeniz A, Hacihanefioglu U: Abscess formation in an intrathoracic goitre. Thorax 37556, 1982 66. Fui SNT, Prior J, Saunders AJ, Maisey MN: Posterior intrathoracic goitre as a cause of thyrotoxicosis. Br J Radiol 52995, 1979 67. Jauregui R, Lilker ES, Bayley A: Upper airway obstruction in euthyroid goiter. JAMA 238:2163, 1977 68. Glazer GM, Axel L, Moss AA: CT diagnosis of mediastinal thyroid. AJR 138:495, 1982 69. Adams HD: Transthoracic thyroidectomy. J Thorac Surg 19:741, 1950 70. Irwin RS, Braman SS, Arvanitidis AN, Hamolsky MW: 131 iodine thyroid scanning in preoperative diagnosis of mediastinal goiter. Ann Intern Med 89:73, 1978 71. Nejatheim M, Strashun A M CT versus iodine scanning in diagnosis of mediastinal thyroid (letter). AJR 1392334, 1982 72. Elhence IF, Trehon OF, Gupta CK, Sikroria S, Sharma BD: Thyroid lymphography. Int Surg 62:583, 1977 73. Wang CA, Vickery AL Jr, Maloof F: Needle biopsy of the thyroid. Surg Gynecol Obstet 143:365, 1976 74. Wang CA, Guyton ST, Vickery AL Jr: A further note on the large needle biopsy of the thyroid gland. Surg Gynecol Obstet 156:509, 1983 75. Mishriki YY, Lane BP, Lozowski MS, Epstein H: Hiirthlecell tumor arising in the mediastinal ectopic thyroid and diagnosed by fine needle aspiration. Acta Cytol (Baltimore) 27:188, 1983 76. Case Records of the Massachusetts General Hospital: case 24191. N Engl J Med 218816, 1938 77. Lindem MD Jr, Clark JH: Indications for surgery in thyroiditis. Am J Surg 118:829, 1969
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Notice from the American Board of Thoracic Surgery The American Board of Thoracic Surgery began its recertification process i n 1984. Diplomates interested in participating i n recertification should maintain a documented list of the cardiothoracic operations they performed during the year prior to application for recertification. They should also keep a record of their attendance a t thoracic surgical meetings a n d other continuing education medical activities for the t w o years prior to application for recertification. In place of a cognitive examination, candidates for recertification will be required to complete both the general thoracic a n d cardiac portions of the SESATS I1 Syllabus (Self-Education/Self-Assessment in Thoracic Surgery). It is n o t necessary for candidates to purchase
SESATS I1 prior t o applying for recertification. SESATS I1 booklets will be forwarded to candidates after their applications have been received. Diplomates whose ten-year certificates will expire in 1987 may begin t h e recertification process in 1985. This new certificate will b e dated ten years from the time of expiration of the original certificate. Recertification is also open to any Diplomate with a n unlimited certificate. The deadline for submission of applications for recertification is July 1, 1985. A recertification brochure outlining t h e rules a n d requirements for recertification in thoracic surgery is available on request from the American Board of Thoracic Surgery, 14640 E Seven Mile Rd, Detroit, MI 48205.