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Recurrent substernal nodular goiter: Incidence and management
Recurrent substernal nodular goiter: Incidence and management Brian Hsu, MB, Tom S. Reeve, MD, Ana I. Guinea, BSc, Bruce Robinson, MD, and Leigh Delbridge, MD, Sydney, Australia
Background. Surgery for recurrent multinodular goiter is associated with an increased risk of complications. When recurrence occurs in a substernal location, difficulties associated with surgical removal may be even more significant, Methods. Information relating to indications for surgery, procedure performed, pathologic findings, and surgical complications was obtained from a prospective thywid surgeU database maintained in our unit for the past 39 years. Results. During the study period 234 patients underwent operation for retrosternal recurrence of a nodular goiter. In the majority of cases (51%) the indication for surgery was the presence of compressive symptoms. In only four cases was a ste,vzal aplit required to remove substernal recurrence. Complications occurred in 35 patients, including four permanent recurrent laryngeal nerve palsies. No patient had permanent hypoparathyroidism. Conclusions. Surgery for recurrent substernal goiter, although technically demanding, can be performed with a minimum of morbidity if appropriate attention is paid to anatomy and embryology. A sternal split is only rarely required. (Surgery 1996;120:1072-5.) From the Endocrine Surgical Unit, Royal North Share Hospital, Sydney, Australia
SUBTOTAL THYROIDECTOMY FOR
multinodular goiter may
lead to recurrence many years later. T h e m a n a g e m e n t o f r e c u r r e n t goiter in the cervical region is generally straightforward, although secondary thyroidectomy does carry a higher risk o f complications. 1 If the recurrence occurs substernally, however, significant problems may arise as a result of increased difficulty of surgical management. It is often t h o u g h t that sternal split is almost always r e q u i r e d to deal with substernal recurreiace o f a n o d u l a r goiter because of the d e v e l o p m e n t of a parasitic b l o o d supply to the susternal c o m p o n e n t of the goiter. T h e aim of this p a p e r was to examine the incidence a n d surgical m a n a g e m e n t of r e c u r r e n t substernal n o d u l a r goiter.
PATIENTS A N D M E T H O D S Information on the indications for surgery, surgical p r o c e d u r e performed, pathologic findings, a n d complications was obtained from the thyroid surgery database at Royal N o r t h Shore Hospital. Information on all patients u n d e r g o i n g thyroid a n d parathyroid surgery in the e n d o c r i n e surgical unit has b e e n r e c o r d e d prospecPresented at the Seventeenth Annual Meeting of the American Association of Endocrine Surgeons, Napa, Calif.,April 21-23, 1996. Reprint requests: L. Delbridge, MD, Department of Surgery, Royal North Shore Hospital, St. Leonards 2065, Sydney,Australia. Copyright 9 1996 by Mosby-YearBook, Inc. 0039-6060/96/$5.00+ 0 11/6/76611
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tively on this database since 1957. T h e database now contains records o n 10,164 procedures. I n c l u d e d in the study group were all patients undergoing secondary thyroidectomy for a diagnosed substernal n o d u l a r goiter or who were n o t e d to have a substernal c o m p o n e n t to their r e c u r r e n t goiter at operation. Substernal was defined as the presence of thyroid tissue, either clinically o r radiologically, below the manubriosternal junction. During the 39-year p e r i o d between January 1957 and D e c e m b e r 1995, 234 patients u n d e r w e n t secondary thyr o i d e c t o m y for substernal n o d u l a r goiter. During that same p e r i o d 1585 patients u n d e r w e n t operation for a primary substernal goiter a n d 229 thyroidectomies were p e r f o r m e d for a cervical recurrence of m u l t i n o d u l a r goiter. T h e female to male ratio was 7.35:1. The majority of patients (93%) were o l d e r than 40 years of age, with a m e a n age o f 60,1 years (range, 23 to 88 years).
RESULTS Table I shows the indication for operation for all 234 cases. T h e most c o m m o n reason for operation was the presence o f compressive symptoms (119 of 234), representing 51% of the group. Substernal location of an asymptomatic goiter was also a c o m m o n indication for surgical m a n a g e m e n t in 83 cases (35%). In all cases the intent o f the p r o c e d u r e was to remove all visible r e m a i n i n g thyroid tissue. The extent o f oper-
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Table I. Indication tbr surgery of the 234 cases
Reason
No.
Percentage
Substernal location (asymptomatic) Compression Cancer suspected within nodular goiter Thyrotoxic Hyperparathyroid Total
83
35
119 25
51 11
6 1 234
2.6 0.4 100
ation required to achieve this aim is shown in Table II. One h u n d r e d six (45%) hemithyroidectomies and 58 (25%) completion total thyroidectomies were performed. The remaining 70 (30%) underwent some form of partial thyroidectomy. In only four cases was a sternal split required to remove a recurrent retrosternal goiter. The reasons for proceeding to sternal split in each of these cases are shown in Table IlL Table IV shows the final histologic diagnosis in each case. Eighteen (7.7%) substernal goiters were subsequently f o u n d to contain malignancy. Papillary carcin o m a (10 of 18) predominated in the malignant group. Significant postoperative complications occurred in 35 patients (15%). Thirty-two of these had only one complication, and three had more than one complication. The complications are shown in Table V.
DISCUSSION The incidence of substernal goiter varies widely with the geographic and population distribution; it has been reported in between 1.7% and 30% of thyroidectomies performed. 2-6 The discrepancy may also relate to differences in the definition of substernal. The incidence of recurrent substernal nodular goiter has not been widely reported at all. Most reports on substernal goiters do not specifically distinguish between primary or secondary procedures. Katie et al. 7 reported 15 patients (19%) o f 80 undergoing operation for substernal goiter who had prior thyroid surgery. In their study o f 218 operated cases of substernal goiters Cougard et al. s reported 24 cases (11%) of relapsing thoracic goiters. Maruotti et al. 9 reported 3 (5.9%) of 51 patients who underwent resection of a substernal goiter had previous thyroid surgery. The incidence of recurrent substernal goiter disease appears to be between 2.9% "~and 19%. 5 In our unit during the period between 1957 and 1995, 234 patients who underwent resection of substernal goiters had all undergone previous thyroid operations. They comprised 2.4% of all procedures, 6.1% of operations for multinodular goiter disease, and 30% of secondary thyroidectomies for other causes.
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T a b l e II. Extent of surgery required to remove all visible remaining thyroid tissue
Type of procedure
No.
Percentage
Hemithyroidectomy Partial thyroidectomy Completion total thyroidectomy Total
106 70 58
45 30 25
234
100
The most c o m m o n reason for operation was compression (119 of 234, 51%), followed by diagnosis of an asymptomatic substernal goiter (83 of 234, 35%). In the study by Katlic et al. 7 of 80 patients undergoing resection of substernal goiter, they reported that 69% of the patients had symptoms of a cervical mass. Thirty-three percent of patients in that study had dysphagia, 28 % had dyspnea, and 16% had stridor. Thirteen percent were asymptomatic. Maruotti et al.9 reported airway compression in 56.8% of patients, hoarseness in 13.7%, dysphagia in 11.7%, and 23.5% were asymptomatic. In our study in more than one haft of cases the indication for operation was compression. A significant proportion (35%) of patients were asymptomatic. Although the indication for operation in most recurrent substernal goiters is compression, which parallels that of primary thyroidectomy of substernal goiters, the incidence of asymptomatic substernal recurrence is significantly higher than in the primary situation. Eighty-two percent of the recurrences were histologically diagnosed as benign multinodular goiters (191 of 234). Eighteen (7.7%) of 234 were subsequently found to contain malignancy, with papillary cancer predominating. The incidence of malignancy in substernal goiters has been reported to be 2% to 3% of substernal goiters,7, 9 but it would appear that recurrent substernal goiters have a higher incidence o f malignancy, including incidental papillary carcinoma3 ~ Significant postoperative complications occurred in 35 patients. The incidence o f recurrent laryngeal nerve (RLN) palsy was 1.3% (3 of 234). This is comparable with the previously reported incidence of operative RLN palsy at secondary thyroidectomy for cervical goiters (1.4% for 1967 to 1981 and 1.6% for 1982 to 1987).1 The reported incidence of RLN palsy in patients undergoing thyroidectomy for cervical multinodular goiter in this unit was 1 in 853 from 1975 to 1985.11 Clearly secondary thyroidectomy carries a greater risk of RLN palsy when compared with primary thyroidectomies in the m a n a g e m e n t of multinodular goiter, but the risk is almost identical to secondary thyroidectomies for cervical nmltinodular goiter. Three tracheostomies were required, one for wound hemorrhage, one for temporary
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T a b l e I I I . Decision making in four patients requiring sternal split
Age (yr) 46 70 75 80
Gender F F F F
Disease
Timing of decision
Multinodular goiter Multinodular goiter Multinodular goiter Multinodular goiter
At operation Before operation Before operation Before operation
Reason for sternal split Isolated substernal component inaccessible from neck Substernal component larger than thoracic inlet Isolated retrosternal nodule inaccessible from neck Isolated mediastinal mass next to pericardium inaccessible from neck
T a b l e V. Significant postoperative complications that occurred in 234 patients
T a b l e IV. Final histologic diagnosis of 234 retrosternal goiters
Diagnosis
No.
Percentage
Benign multinodular goiter Follicular adenoma Colloid nodule Hashimoto's thyroiditis Graves' disease (diffuse hyperplasia) Carcinoma Follicular Papillary Medullary Total
191 9 13 2 1
82 3.8 5 1 0.5
18 7 10 1 234
7.7
Major complications Incidence .(% of 35) (% of 234) Temporary hypocalcenfia Vocal cord dysfunction Recurrent laryngeal nerve palsy Hematoma Hemorrhage with reoperation Wound infection Tracheostomy Total
12 8 3 4 3 2 ~ 35
(34) (23) (9) (11) (9) (5) (9) (100)
5.1 3.4 1.3 1.7 1.3 0.8 1.3 234 (14.9)
100
bilateral RLN paresis, and one related to intraoral b l e e d i n g after extubation. T h e fact that this operation is p e r f o r m e d in a generally older p o p u l a t i o n increases the risk o f comorbidity. Four (1.7%) of patients in this series r e q u i r e d a sternal split for m a n a g e m e n t of substernal recurrence o f n o d u l a r goiter. This compares with our previously published data 12 for the m a n a g e m e n t of primary substernal goiter, in which only four of 1017 patients required a sternal split. In no case was this caused by a parasitic b l o o d supply derived from thoracic vessels after previous operation. All the sternal splits were p e r f o r m e d because o f either the relative size o f the substernal c o m p o n e n t c o m p a r e d with the thoracic inlet or inaccessibility of the mediastinal c o m p o n e n t from the neck. T h e surgical a p p r o a c h to r e c u r r e n t substernal goiter varies little from our routine a p p r o a c h to thyroidectomy. A cervical a p p r o a c h is first attempted, with excision of the scar. Significant lateral and central landmarks are first identified, including the internal j u g u l a r vein, c o m m o n carotid vessels, a n d the anterior surface of the trachea. Capsular dissection then proceeds, and significant structures such as the r e c u r r e n t laryngeal nerve and parathyroid glands will generally be f o u n d with time and patience. Occasionally a r e c u r r e n t laryngeal nerve may n e e d to be dissected free from scar tissue. Transplantation o f parathyroid glands is undertaken for any tissue with doubtful viability. T h e retrosternal c o m p o n e n t can usually be delivered by the standard technique of elevation by placing a fin-
ger u n d e r a n d b e h i n d the goiter and lifting it u p a n d forward. T h e most i m p o r t a n t p o i n t is to locate the correct plane within the m e d i a s t i n u m by careful finger dissection. A sternal split is resorted to only, if removal is absolutely prevented by previous scar tissue or if significant bleeding is e n c o u n t e r e d . T h e most significant factor in d e t e r m i n i n g the ease of o p e r a t i o n is the extent o f previous dissection. If a thoro u g h exploration of both sides o f the neck with full dissection o f both r e c u r r e n t laryngeal nerves h a d b e e n previously undertaken, surgery may be very tedious indeed. If, on the o t h e r hand, a posterior dissection was not p e r f o r m e d , a r e c u r r e n t retrosternal goiter may be delivered with the same ease as in the primary situation. Surgery for r e c u r r e n t substernal goiter, although technically demanding, can t~e p e r f o r m e d with a mini m u m of morbidity if attention is p a i d to anatomy, embryology, a n d appropriate surgical technique. REFERENCES
1. ReeveTS, Delbridge L, Brady P, Crummer P, Smyth C. Secondary thyroidectomy: a twenty year experience. World J Surg 1988;12:449-53. 2. ReeveTS, Rundle FF,HalesJB,et al. The investigationand management of substernalgoila-e.Slug GynecolObstet 1962;115: 223-9. 3. WakeleyCPG, MulvanyJH. Substernal goitre. Surg Gynecol Obstet 1940;70:702-10. 4. Michel LA, Bradpiece HA. Surgical management of substernal goitre. BrJ Surg 1988;75:565-9. 5. Shahian DM. Surgicaltreatment of substernal goitre. In: CadyB, RossiRL, editors. Surgeryof the thyroid and parathyroid glands. 3rd ed. Saunders; Philadelphia, 1980:215-22.
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6. Allo MD, Thompson NW. Rationale for the operative management of substernal goiters. Surgery 1983;94:969-77. 7. Kadic MR, Grillo HC, Wang CA. Substernal goitre: analysisof 80 patients from Massachusetts General Hospital. Am J Surg 1985;149:283-7. 8. Cougard P, Matet P, Goudet P, Bambili R, Viard H, Vaitlant G, et al. Substernal goitres: 218 operated cases [in French]. Ann Endocrinol (Paris) 1992;53:230-5. 9. Maruotti RA, Zannini P, Viani MP, Voci C, Pezzuoli G. Surgical treatment of substernal goitres. Int Surg 1991;76:12-7. 10. Snaders LA, Rossi RL, Shahian DM, Williamson WA. Mediastinal goitres: the need tbr an agressive approach. Arch Surg 1992;155: 429-31. 11. Reeve TS, Delbridge L, Cohen A, Crummer P. Total thyroidectomy: the preferred option for multinodular goiter. Ann Surg 1987;206:782-6. 12. Reeve TS, Delbridge L. Endocrine tumours of the mediastinum. In: Wood DE, Thomas CR, editors. Medical radiology: diagnostic imaging and radiation oncology--mediastinal tumours. Macmillan: Bangalore India, 1995:55-62.
DISCUSSION Dr. Ashok R. Shaha (New York, NY). O n the basis of this information what do you do now when a patient presents with nodular goiter in the neck? Do you perform total thyroidectomy, subtotal, or which part do you leave? If the entire thyroid is nodular, what do you do? Second, were any of these patients on suppressive therapy after their previous operation and did that make any difference? Dr. Delbridge. We now perform total thyroidectomy for nodular goiter because of the problem with recurrence. It may be a regional p h e n o m e n o n in our country but certainlyyou see a high incidence of recurrence, so we perform total in the first instance, which essentially removes this problem. Half of our patients who experience recurrence are on thyroxine, and it seems to make no difference to development of recurrence. Dr. Jay K. Harness (Oakland, CA). How many of these patients were operated on originally in yore unit or bY similarly highly qualified endocrine surgeons? Or were these patients referred because they had been operated on by others? Dr. Delbridge. I can not give you a figure for the whole series because unfortunately our database for the first 20 years did not record where the previous surgery was performed. For the last 10 years about 50% were performed within
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our unit originally, mostly more than 10 years previously. The remaining 50% had their primary surgery performed elsewhere. Dr. Charles P r o y e (Lille, France). What about your technique of dissection of the inferior recurrent laryngeal nerve? Do you see and dissect it before or after delivery of the thoracic portion of the goiter? Dr. Delhridge. We deliver the substernal portion first. I think that is the key. It is difficult to come to terms with the fact that you cannot see the nerve in the fibrosis until you deliver the goiter, and you find it flops over and invariably the nerve is in the groove once you have got it out. Occasionally you get stuck and you have to go back, but in most instances the goiter comes up before you have to turn your attention to the nerve. Dr. Proye. The critical point is to dissect first the space between the inner aspect of the superior pole of the thyroid lobe and the cricothyroid membrane. T h e n you see the nerve at its ending. Then you can find and develop a plane posterior to the thyroid but also at the anterior aspect of the nerve, and you slip in perfect safety along the posterior aspect of the substernal lobe and deliver it upwards in the neck. I prefer this so-called toboggan technique rather than your dunking maneuver. Dr. Christopher R. MeHenry (Cleveland, OH). Did any of your patients have tracheomalacia? Do you have any experience with primary intrathoracic goiter that develops from congenitally ectopic thyroid tissue and requires a median sternotomy as opposed to a cervical exploration? Dr. Delbridge. Tracheomalacia is exceedingly rare. It is not a problem. If you have a constricting goiter, you take it out, and the trachea invariably expands. I d o n ' t quite understand these reports that show a high incidence of it. As far as congenital abnormalities, we have had very occasionally a totally isolated intrathoracic goiter, and that requires a primary sternal split. I have never seen it in a recurrent situation. Dr. Irving B. Rosen (Toronto, Ontario, Canada). Morcellation sounds like an antique term. Have you had any experience with this maneuver? What are your feelings about it? Dr. Delhridge. We d o n ' t do morcellation. Occasionally when you are pulling it out, it will sort of fall apart in bits on the way. So it is accidental morcellation, but it was never our intent to do that.
Background. Surgery for recurrent multinodular goiter is associated with an increased risk of complications. When recurrence occurs in a substernal location, difficulties associated with surgical removal may be even more significant, Methods. Information relating to indications for surgery, procedure performed, pathologic findings, and surgical complications was obtained from a prospective thywid surgeU database maintained in our unit for the past 39 years. Results. During the study period 234 patients underwent operation for retrosternal recurrence of a nodular goiter. In the majority of cases (51%) the indication for surgery was the presence of compressive symptoms. In only four cases was a ste,vzal aplit required to remove substernal recurrence. Complications occurred in 35 patients, including four permanent recurrent laryngeal nerve palsies. No patient had permanent hypoparathyroidism. Conclusions. Surgery for recurrent substernal goiter, although technically demanding, can be performed with a minimum of morbidity if appropriate attention is paid to anatomy and embryology. A sternal split is only rarely required. (Surgery 1996;120:1072-5.) From the Endocrine Surgical Unit, Royal North Share Hospital, Sydney, Australia
SUBTOTAL THYROIDECTOMY FOR
multinodular goiter may
lead to recurrence many years later. T h e m a n a g e m e n t o f r e c u r r e n t goiter in the cervical region is generally straightforward, although secondary thyroidectomy does carry a higher risk o f complications. 1 If the recurrence occurs substernally, however, significant problems may arise as a result of increased difficulty of surgical management. It is often t h o u g h t that sternal split is almost always r e q u i r e d to deal with substernal recurreiace o f a n o d u l a r goiter because of the d e v e l o p m e n t of a parasitic b l o o d supply to the susternal c o m p o n e n t of the goiter. T h e aim of this p a p e r was to examine the incidence a n d surgical m a n a g e m e n t of r e c u r r e n t substernal n o d u l a r goiter.
PATIENTS A N D M E T H O D S Information on the indications for surgery, surgical p r o c e d u r e performed, pathologic findings, a n d complications was obtained from the thyroid surgery database at Royal N o r t h Shore Hospital. Information on all patients u n d e r g o i n g thyroid a n d parathyroid surgery in the e n d o c r i n e surgical unit has b e e n r e c o r d e d prospecPresented at the Seventeenth Annual Meeting of the American Association of Endocrine Surgeons, Napa, Calif.,April 21-23, 1996. Reprint requests: L. Delbridge, MD, Department of Surgery, Royal North Shore Hospital, St. Leonards 2065, Sydney,Australia. Copyright 9 1996 by Mosby-YearBook, Inc. 0039-6060/96/$5.00+ 0 11/6/76611
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tively on this database since 1957. T h e database now contains records o n 10,164 procedures. I n c l u d e d in the study group were all patients undergoing secondary thyroidectomy for a diagnosed substernal n o d u l a r goiter or who were n o t e d to have a substernal c o m p o n e n t to their r e c u r r e n t goiter at operation. Substernal was defined as the presence of thyroid tissue, either clinically o r radiologically, below the manubriosternal junction. During the 39-year p e r i o d between January 1957 and D e c e m b e r 1995, 234 patients u n d e r w e n t secondary thyr o i d e c t o m y for substernal n o d u l a r goiter. During that same p e r i o d 1585 patients u n d e r w e n t operation for a primary substernal goiter a n d 229 thyroidectomies were p e r f o r m e d for a cervical recurrence of m u l t i n o d u l a r goiter. T h e female to male ratio was 7.35:1. The majority of patients (93%) were o l d e r than 40 years of age, with a m e a n age o f 60,1 years (range, 23 to 88 years).
RESULTS Table I shows the indication for operation for all 234 cases. T h e most c o m m o n reason for operation was the presence o f compressive symptoms (119 of 234), representing 51% of the group. Substernal location of an asymptomatic goiter was also a c o m m o n indication for surgical m a n a g e m e n t in 83 cases (35%). In all cases the intent o f the p r o c e d u r e was to remove all visible r e m a i n i n g thyroid tissue. The extent o f oper-
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Table I. Indication tbr surgery of the 234 cases
Reason
No.
Percentage
Substernal location (asymptomatic) Compression Cancer suspected within nodular goiter Thyrotoxic Hyperparathyroid Total
83
35
119 25
51 11
6 1 234
2.6 0.4 100
ation required to achieve this aim is shown in Table II. One h u n d r e d six (45%) hemithyroidectomies and 58 (25%) completion total thyroidectomies were performed. The remaining 70 (30%) underwent some form of partial thyroidectomy. In only four cases was a sternal split required to remove a recurrent retrosternal goiter. The reasons for proceeding to sternal split in each of these cases are shown in Table IlL Table IV shows the final histologic diagnosis in each case. Eighteen (7.7%) substernal goiters were subsequently f o u n d to contain malignancy. Papillary carcin o m a (10 of 18) predominated in the malignant group. Significant postoperative complications occurred in 35 patients (15%). Thirty-two of these had only one complication, and three had more than one complication. The complications are shown in Table V.
DISCUSSION The incidence of substernal goiter varies widely with the geographic and population distribution; it has been reported in between 1.7% and 30% of thyroidectomies performed. 2-6 The discrepancy may also relate to differences in the definition of substernal. The incidence of recurrent substernal nodular goiter has not been widely reported at all. Most reports on substernal goiters do not specifically distinguish between primary or secondary procedures. Katie et al. 7 reported 15 patients (19%) o f 80 undergoing operation for substernal goiter who had prior thyroid surgery. In their study o f 218 operated cases of substernal goiters Cougard et al. s reported 24 cases (11%) of relapsing thoracic goiters. Maruotti et al. 9 reported 3 (5.9%) of 51 patients who underwent resection of a substernal goiter had previous thyroid surgery. The incidence of recurrent substernal goiter disease appears to be between 2.9% "~and 19%. 5 In our unit during the period between 1957 and 1995, 234 patients who underwent resection of substernal goiters had all undergone previous thyroid operations. They comprised 2.4% of all procedures, 6.1% of operations for multinodular goiter disease, and 30% of secondary thyroidectomies for other causes.
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T a b l e II. Extent of surgery required to remove all visible remaining thyroid tissue
Type of procedure
No.
Percentage
Hemithyroidectomy Partial thyroidectomy Completion total thyroidectomy Total
106 70 58
45 30 25
234
100
The most c o m m o n reason for operation was compression (119 of 234, 51%), followed by diagnosis of an asymptomatic substernal goiter (83 of 234, 35%). In the study by Katlic et al. 7 of 80 patients undergoing resection of substernal goiter, they reported that 69% of the patients had symptoms of a cervical mass. Thirty-three percent of patients in that study had dysphagia, 28 % had dyspnea, and 16% had stridor. Thirteen percent were asymptomatic. Maruotti et al.9 reported airway compression in 56.8% of patients, hoarseness in 13.7%, dysphagia in 11.7%, and 23.5% were asymptomatic. In our study in more than one haft of cases the indication for operation was compression. A significant proportion (35%) of patients were asymptomatic. Although the indication for operation in most recurrent substernal goiters is compression, which parallels that of primary thyroidectomy of substernal goiters, the incidence of asymptomatic substernal recurrence is significantly higher than in the primary situation. Eighty-two percent of the recurrences were histologically diagnosed as benign multinodular goiters (191 of 234). Eighteen (7.7%) of 234 were subsequently found to contain malignancy, with papillary cancer predominating. The incidence of malignancy in substernal goiters has been reported to be 2% to 3% of substernal goiters,7, 9 but it would appear that recurrent substernal goiters have a higher incidence o f malignancy, including incidental papillary carcinoma3 ~ Significant postoperative complications occurred in 35 patients. The incidence o f recurrent laryngeal nerve (RLN) palsy was 1.3% (3 of 234). This is comparable with the previously reported incidence of operative RLN palsy at secondary thyroidectomy for cervical goiters (1.4% for 1967 to 1981 and 1.6% for 1982 to 1987).1 The reported incidence of RLN palsy in patients undergoing thyroidectomy for cervical multinodular goiter in this unit was 1 in 853 from 1975 to 1985.11 Clearly secondary thyroidectomy carries a greater risk of RLN palsy when compared with primary thyroidectomies in the m a n a g e m e n t of multinodular goiter, but the risk is almost identical to secondary thyroidectomies for cervical nmltinodular goiter. Three tracheostomies were required, one for wound hemorrhage, one for temporary
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T a b l e I I I . Decision making in four patients requiring sternal split
Age (yr) 46 70 75 80
Gender F F F F
Disease
Timing of decision
Multinodular goiter Multinodular goiter Multinodular goiter Multinodular goiter
At operation Before operation Before operation Before operation
Reason for sternal split Isolated substernal component inaccessible from neck Substernal component larger than thoracic inlet Isolated retrosternal nodule inaccessible from neck Isolated mediastinal mass next to pericardium inaccessible from neck
T a b l e V. Significant postoperative complications that occurred in 234 patients
T a b l e IV. Final histologic diagnosis of 234 retrosternal goiters
Diagnosis
No.
Percentage
Benign multinodular goiter Follicular adenoma Colloid nodule Hashimoto's thyroiditis Graves' disease (diffuse hyperplasia) Carcinoma Follicular Papillary Medullary Total
191 9 13 2 1
82 3.8 5 1 0.5
18 7 10 1 234
7.7
Major complications Incidence .(% of 35) (% of 234) Temporary hypocalcenfia Vocal cord dysfunction Recurrent laryngeal nerve palsy Hematoma Hemorrhage with reoperation Wound infection Tracheostomy Total
12 8 3 4 3 2 ~ 35
(34) (23) (9) (11) (9) (5) (9) (100)
5.1 3.4 1.3 1.7 1.3 0.8 1.3 234 (14.9)
100
bilateral RLN paresis, and one related to intraoral b l e e d i n g after extubation. T h e fact that this operation is p e r f o r m e d in a generally older p o p u l a t i o n increases the risk o f comorbidity. Four (1.7%) of patients in this series r e q u i r e d a sternal split for m a n a g e m e n t of substernal recurrence o f n o d u l a r goiter. This compares with our previously published data 12 for the m a n a g e m e n t of primary substernal goiter, in which only four of 1017 patients required a sternal split. In no case was this caused by a parasitic b l o o d supply derived from thoracic vessels after previous operation. All the sternal splits were p e r f o r m e d because o f either the relative size o f the substernal c o m p o n e n t c o m p a r e d with the thoracic inlet or inaccessibility of the mediastinal c o m p o n e n t from the neck. T h e surgical a p p r o a c h to r e c u r r e n t substernal goiter varies little from our routine a p p r o a c h to thyroidectomy. A cervical a p p r o a c h is first attempted, with excision of the scar. Significant lateral and central landmarks are first identified, including the internal j u g u l a r vein, c o m m o n carotid vessels, a n d the anterior surface of the trachea. Capsular dissection then proceeds, and significant structures such as the r e c u r r e n t laryngeal nerve and parathyroid glands will generally be f o u n d with time and patience. Occasionally a r e c u r r e n t laryngeal nerve may n e e d to be dissected free from scar tissue. Transplantation o f parathyroid glands is undertaken for any tissue with doubtful viability. T h e retrosternal c o m p o n e n t can usually be delivered by the standard technique of elevation by placing a fin-
ger u n d e r a n d b e h i n d the goiter and lifting it u p a n d forward. T h e most i m p o r t a n t p o i n t is to locate the correct plane within the m e d i a s t i n u m by careful finger dissection. A sternal split is resorted to only, if removal is absolutely prevented by previous scar tissue or if significant bleeding is e n c o u n t e r e d . T h e most significant factor in d e t e r m i n i n g the ease of o p e r a t i o n is the extent o f previous dissection. If a thoro u g h exploration of both sides o f the neck with full dissection o f both r e c u r r e n t laryngeal nerves h a d b e e n previously undertaken, surgery may be very tedious indeed. If, on the o t h e r hand, a posterior dissection was not p e r f o r m e d , a r e c u r r e n t retrosternal goiter may be delivered with the same ease as in the primary situation. Surgery for r e c u r r e n t substernal goiter, although technically demanding, can t~e p e r f o r m e d with a mini m u m of morbidity if attention is p a i d to anatomy, embryology, a n d appropriate surgical technique. REFERENCES
1. ReeveTS, Delbridge L, Brady P, Crummer P, Smyth C. Secondary thyroidectomy: a twenty year experience. World J Surg 1988;12:449-53. 2. ReeveTS, Rundle FF,HalesJB,et al. The investigationand management of substernalgoila-e.Slug GynecolObstet 1962;115: 223-9. 3. WakeleyCPG, MulvanyJH. Substernal goitre. Surg Gynecol Obstet 1940;70:702-10. 4. Michel LA, Bradpiece HA. Surgical management of substernal goitre. BrJ Surg 1988;75:565-9. 5. Shahian DM. Surgicaltreatment of substernal goitre. In: CadyB, RossiRL, editors. Surgeryof the thyroid and parathyroid glands. 3rd ed. Saunders; Philadelphia, 1980:215-22.
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6. Allo MD, Thompson NW. Rationale for the operative management of substernal goiters. Surgery 1983;94:969-77. 7. Kadic MR, Grillo HC, Wang CA. Substernal goitre: analysisof 80 patients from Massachusetts General Hospital. Am J Surg 1985;149:283-7. 8. Cougard P, Matet P, Goudet P, Bambili R, Viard H, Vaitlant G, et al. Substernal goitres: 218 operated cases [in French]. Ann Endocrinol (Paris) 1992;53:230-5. 9. Maruotti RA, Zannini P, Viani MP, Voci C, Pezzuoli G. Surgical treatment of substernal goitres. Int Surg 1991;76:12-7. 10. Snaders LA, Rossi RL, Shahian DM, Williamson WA. Mediastinal goitres: the need tbr an agressive approach. Arch Surg 1992;155: 429-31. 11. Reeve TS, Delbridge L, Cohen A, Crummer P. Total thyroidectomy: the preferred option for multinodular goiter. Ann Surg 1987;206:782-6. 12. Reeve TS, Delbridge L. Endocrine tumours of the mediastinum. In: Wood DE, Thomas CR, editors. Medical radiology: diagnostic imaging and radiation oncology--mediastinal tumours. Macmillan: Bangalore India, 1995:55-62.
DISCUSSION Dr. Ashok R. Shaha (New York, NY). O n the basis of this information what do you do now when a patient presents with nodular goiter in the neck? Do you perform total thyroidectomy, subtotal, or which part do you leave? If the entire thyroid is nodular, what do you do? Second, were any of these patients on suppressive therapy after their previous operation and did that make any difference? Dr. Delbridge. We now perform total thyroidectomy for nodular goiter because of the problem with recurrence. It may be a regional p h e n o m e n o n in our country but certainlyyou see a high incidence of recurrence, so we perform total in the first instance, which essentially removes this problem. Half of our patients who experience recurrence are on thyroxine, and it seems to make no difference to development of recurrence. Dr. Jay K. Harness (Oakland, CA). How many of these patients were operated on originally in yore unit or bY similarly highly qualified endocrine surgeons? Or were these patients referred because they had been operated on by others? Dr. Delbridge. I can not give you a figure for the whole series because unfortunately our database for the first 20 years did not record where the previous surgery was performed. For the last 10 years about 50% were performed within
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our unit originally, mostly more than 10 years previously. The remaining 50% had their primary surgery performed elsewhere. Dr. Charles P r o y e (Lille, France). What about your technique of dissection of the inferior recurrent laryngeal nerve? Do you see and dissect it before or after delivery of the thoracic portion of the goiter? Dr. Delhridge. We deliver the substernal portion first. I think that is the key. It is difficult to come to terms with the fact that you cannot see the nerve in the fibrosis until you deliver the goiter, and you find it flops over and invariably the nerve is in the groove once you have got it out. Occasionally you get stuck and you have to go back, but in most instances the goiter comes up before you have to turn your attention to the nerve. Dr. Proye. The critical point is to dissect first the space between the inner aspect of the superior pole of the thyroid lobe and the cricothyroid membrane. T h e n you see the nerve at its ending. Then you can find and develop a plane posterior to the thyroid but also at the anterior aspect of the nerve, and you slip in perfect safety along the posterior aspect of the substernal lobe and deliver it upwards in the neck. I prefer this so-called toboggan technique rather than your dunking maneuver. Dr. Christopher R. MeHenry (Cleveland, OH). Did any of your patients have tracheomalacia? Do you have any experience with primary intrathoracic goiter that develops from congenitally ectopic thyroid tissue and requires a median sternotomy as opposed to a cervical exploration? Dr. Delbridge. Tracheomalacia is exceedingly rare. It is not a problem. If you have a constricting goiter, you take it out, and the trachea invariably expands. I d o n ' t quite understand these reports that show a high incidence of it. As far as congenital abnormalities, we have had very occasionally a totally isolated intrathoracic goiter, and that requires a primary sternal split. I have never seen it in a recurrent situation. Dr. Irving B. Rosen (Toronto, Ontario, Canada). Morcellation sounds like an antique term. Have you had any experience with this maneuver? What are your feelings about it? Dr. Delhridge. We d o n ' t do morcellation. Occasionally when you are pulling it out, it will sort of fall apart in bits on the way. So it is accidental morcellation, but it was never our intent to do that.