Click here for Frequently Asked Questions on Thyroid Surgery.
This section provides a general overview of thyroid surgery. The extent of surgery for patients with hyperthyroidism will be different compared to surgery carried out in the context of thyroid cancer. Most of the discussion below is written for patients considering surgery for suspected thyroid cancer, and may not completely apply to patients having surgery for hyperthyroidism. The type of operation carried out for patients with hyperthyroidism may vary somewhat, and should be discussed with your surgeon.
Once a decision for thyroid surgery has been made, the extent and type of the operation depends on a number of factors, including: patient age, gender, size of the nodule, the suspected preoperative diagnosis including the result of the fine needle aspiration biopsy, presence or absence of involved lymph nodes in the neck, the intraoperative analysis of the tumor by the Pathologist (quick section), and the technical ease of the initial part of the operation. The description below generally refers to the situation encountered by patients who have surgery because of the possibility of thyroid cancer.
Thyroid operations are almost always performed under general anesthesia although local anesthetics may be added to decrease the amount of general anesthetic drugs required. The incision is placed in the low anterior neck at the collar line, following an existing skin crease if one is present, and a gentle curve, if not. The incision will vary in length depending on the size of the nodule, the size and shape of your neck, and the surgeon’s preferences. In general, thyroidectomy incisions tend to be between 5 to 10 centimeters in length.
The minimal extent of surgery for a thyroid nodule is a hemithyroidectomy, i.e. removal of one lobe or one half of the thyroid gland. Historical attempts to remove the nodule alone (enucleation) are associated with an increased risk of bleeding and/or tumor spill and spread.
In a hemithyroidectomy operation, where ~ half of the thyroid gland is removed, the blood supply to the thyroid is divided adjacent to the gland, the recurrent laryngeal nerve is identified and followed up to the voice box and the parathyroid glands on that side are left undisturbed if possible.
Once the involved half of the thyroid has been removed, the tissue is sent immediately for frozen or quick section analysis by a pathologist. At this point a decision is made as to whether to remove the other half of the thyroid gland (total thyroidectomy). It is important to understand that the frozen section is only helpful when positive for cancer and is not 100% accurate. For example, in some cases when the frozen section is judged to be "negative for malignancy", the final report may come back as positive for malignancy. This discrepancy reflects the limitations of the quick section diagnosis, and the more comprehensive analysis and special pathological tests that may be carried out following subsequent careful examination of the entire resected pathology specimen. The extent of initial surgery remains a subject of controversy for patients with well differentiated thyroid cancer and small thyroid tumors less than 2-3 cm in size that are confined to one lobe of the thyroid without evidence of disease outside the thyroid. Some centers advocate only a hemithyroidectomy for patients with small tumors, whereas other centers prefer a more aggressive approach and subtotal thyroidectomy. There is little good evidence from large prospective randomized studies to support either approach. For an overview, see Thyroid Cancer: Extent of Thyroidectomy Cancer Control 2000 (3):240-245.
In this circumstance, when the final pathology report comes back positive for thyroid cancer, it is sometimes necessary to perform a second operation to remove the remainder of the thyroid gland. To avoid this possibility, some surgeons will recommend a total thyroidectomy at the outset, if the fine needle aspiration biopsy is positive or highly suspicious for cancer or if the size of the thyroid nodule or other associated clinical features strongly predict an increased likelihood of thyroid cancer. The frequency of small foci of papillary carcinoma of the thyroid in the "contralateral lobe" has prompted some experts to recommend near total thyroidectomy as the initial operation of choice, however this recommendation is not based on long-term follow-up data. See Contralateral papillary thyroid cancer is frequent at completion thyroidectomy with no difference in low- and high-risk patients. Thyroid. 2001 11(9):877-81.
Complications of Hemithyroidectomy include those of the anesthetic, risk of wound infection, pneumonia and all of the other potential problems associated with any operation; as well as those risks associated specifically with this procedure. These include a slight, but real risk of change in voice due to injury to the recurrent laryngeal nerve or the superior laryngeal nerve on the side of the thyroid mass being removed.
The likelihood of a permanent injury to the recurrent laryngeal nerve is in the range of 1%, or one in one hundred cases, and would result in a hoarse or breathy voice. If this complication were to occur, the voice box usually accommodates, resulting in gradual improvement in voice quality. If no improvement in voice quality were to occur, however, a small operation could potentially be performed (thyroplasty) to move the paralyzed vocal cord towards the opposite, normal vocal cord. One way or the other, voice quality improves in this situation. Injury to the external branch of the superior laryngeal nerve is uncommon, believed to occur in 2-5% of thyroidectomies, but the precise risk of this complication is unknown. Injury to this nerve does not result in hoarseness, but does produce voice fatigue, difficulty in voice projection, and possible decrease in voice range, especially in upper singing registers. Again, accommodation of the voice box usually occurs over time. The risk of Hypothyroidism following hemithyroidectomy depends on the presence of preexisting thyroid disease, is usually mild, and has been reported to be ~35% in one series. See Hypothyroidisim following hemithyroidectomy: incidence, risk factors, and management Surgery 2000 Dec;128(6):994-8.
Complications of Total Thyroidectomy include injury to the recurrent and superior laryngeal nerves (at twice the rates mentioned above), and potential damage to all four of the parathyroid glands. Following total thyroidectomy, about one in three patients will have a temporary injury to these glands, resulting in a drop in blood calcium level (hypocalcemia). The symptoms of hypocalcemia may include tingling in the finger, toes, and around the mouth. Extremely low calcium levels can also produce muscle cramps or spasms or shortness of breath. If you were to experience any of these symptoms following a thyroidectomy, you should contact your physician or go to the emergency room immediately. Two percent of patient have a permanently low calcium following total thyroidectomy, even when a careful attempt has been made to preserve and protect the parathyroids at the time of the surgery. The treatment of low calcium (hypocalcemia) is calcium tablets and some times vitamin D (see Treatment of hypocalcemia).
An important consideration when contemplating a total thyroidectomy, is the possible requirement for lifelong thyroid hormone replacement. The risk of hypothyroidism after hemithyroidectomy varies widely from study to study; some centers report rates as low as 1%, and after subtotal thyroidectomy in patients without pre-existing thyroid disease, about 4%, as in most cases, the remaining thyroid tissue grows and compensates for the piece removed. Other reports describe a 50% risk of hypothyroidism requiring thyroid hormone replacement after surgery, as outlined in A comparison of total thyroidectomy and lobectomy in the treatment of dominant thyroid nodules. Am Surg. 2002 Aug;68(8):678-82; discussion 682-3.
Excision of neck lymph nodes (modified radical neck dissection or functional neck dissection) is only performed in papillary or follicular thyroid cancer when these nodes are enlarged and proven to be infiltrated with tumor. The major risks of neck dissection include a significant increase in the length of the incision and scar; and a small risk (5%) of injury to the spinal accessory nerve, which would result in weakness of and pain in the shoulder on that side.
What are the risks involved in thyroid surgery?
The answer clearly depends on many factors, such as the extent of surgery, how much of the thyroid will be removed, whether this is the first or second operation, the nature of the thyroid disease present, the presence of co-existing medical conditions, and the skill and experience of the surgeon. The risks of various surgical approaches to the thyroid should be discussed with your surgeon, taking the above factors into consideration. For several reviews of different scenarios, see Assessment of the morbidity and complications of total thyroidectomy. Arch Otolaryngol Head Neck Surg. 2002 Apr;128(4):389-92 and Surgery for recurrent goitre: its complications and their risk factors. Eur J Surg. 2001 Nov;167(11):816-21. and Thyroid surgery: a comparison of outcomes between experts and surgeons in training. Otolaryngol Head Neck Surg. 2001 Jul;125(1):30-3. For an overview of complications arising from thyroid surgery in a large multicentre Italian study, see Complications of Thyroid Surgery: Analysis of a Multicentric Study on 14,934 Patients Operated on in Italy over 5 Years. World J Surg. 2004 Feb 17.
A review of the selected Toronto experience for patients undergoing total thyroidectomy vs initial hemithyroidectomy followed by completion thyroidectomy from 1994-2004 analyzed the complication rate for the different surgical approaches. The rates of hypocalcemia or recurrent laryngeal paralysis were not significantly different for the two procedures, however patients having a completion thyroidectomy had a slightly longer stay in hospital as outlined in Completion Thyroidectomy Versus Total Thyroidectomy: Is There a Difference in Complication Rates? An Analysis of 350 Patients. J Am Coll Surg. 2007 Oct;205(4):602-607.
Some patients with multiple nodules elect to have a subtotal thyroidectomy rather than a hemithyroidectomy, to avoid the need for ongoing surveillance of the remaining nodules. Nevertheless, have multlple nodules does not necessarily increase the risk of having additional foci of thyroid cancer in the remaining nodules, as described in Does the presence of additional thyroid nodules on ultrasound alter the risk of malignancy in patients with a follicular neoplasm of the thyroid? Surgery. 2007 Dec;142 (6): 851-7.
When should I consider surgery for hyperthyroidism?
Although more common in Europe and Asia, surgery is still a reasonable option for some patients with hyperthyroidism. Factors that influence the decision include size of the thyroid, presence of a large nodule, failure of radioactive iodine or drugs, compressive symptoms, severity of eye symptoms, consideration of pregnancy, and patient preferences. To review the experience in this area, see Thyroidectomy for Selected Patients With Thyrotoxicosis. Arch Otolaryngol Head Neck Surg. 2001 Jan;127(1):61-65 and Surgery for Graves' disease: total versus subtotal thyroidectomy-results of a prospective randomized trial World J Surg. 2000 Nov;24(11):1303-11 and Treatment of Graves' disease: the advantages of surgery. Endocrinol Metab Clin North Am. 2000 Jun;29(2):321-37. and The efficacy of thyroidectomy for Graves' disease: A meta-analysis. J Surg Res. 2000 May 15;90(2):161-5.
How effective is surgery for hyperthyroidism?
Although not first line treatment in North America, thyroid surgery appears to be safe and effective with a low rate of complications in an experienced center. See Surgical treatment of hyperthyroidism: a ten-year experience. Thyroid. 2001 Feb;11(2):187-92.
I had most of my thyroid removed and now my physician suggests I have a second operation to remove the remainder of the thyroid. Is this necessary?
The extent and type of additional surgical procedures required in the setting of thyroid cancer treatment will depend in part on the initial pathology report and other associated clinical features. For successful subsequent radioactive iodine ablation treatment, as much of the remaining thyroid as possible should be removed. About 25-35% of patients will have detectable thyroid cancer in the "remnant" part of the thyroid that will be found upon examination of the resected thyroid tissue after a second operation. The single best predictor of thyroid cancer in the thyroid remnant appears to be multifocal thyroid cancer in the original tumor. See Prophylactic completion thyroidectomy for differentiated thyroid carcinoma: prediction of extrathyroidal soft tissue infiltrates. Thyroid. 2001 Apr;11(4):381-4. or Frequency and predictive factors of malignancy in residual thyroid tissue and cervical lymph nodes after partial thyroidectomy for differentiated thyroid cancer. Surgery. 2002 Apr;131(4):443-9. and Completion thyroidectomy in patients with thyroid cancer who initially underwent unilateral operation. Clin Endocrinol (Oxf). 2004 Jul;61(1):145-8.
In some instances, patients will also require a second operation for benign thyroid disease, perhaps due to recurrence of a large goiter or hyperthyroidism. Patients should be aware that the risks and potential complications associated with a second operation are still low, but generally higher than for the first operation, as outlined in Surgery for recurrent goitre: its complications and their risk factors. Eur J Surg. 2001 Nov;167(11):816-21 and Safety of completion thyroidectomy following unilateral lobectomy for well-differentiated thyroid cancer. Laryngoscope. 2002 Jul;112(7 Pt 1):1209-12.
The optimal timing of the second operation will vary depending on the circumstances. Although many surgeons prefer to wait several months before re-exploring the neck, some studies suggest that waiting the extra few months may not make a big difference to the outcome. See Impact of timing on completion thyroidectomy for thyroid cancer. Br J Surg. 2002 Jun;89(6):802-4.
Nevertheless, the detection of small amounts of thyroid cancer in the
other thyroid lobe after a second operation is unlikely to have any
adverse prognostic implications as outlined in Contralateral
papillary thyroid cancer at completion thyroidectomy has no impact on
recurrence or survival after radioiodine treatment. Surgery.
When will minimally invasive surgery become a more widely used procedure for removal of thyroid nodules?
Although experience with this technique is still limited, the number of centers gaining experience with newer approaches to removal of thyroid nodules is increasing. See Minimally invasive video-assisted thyroidectomy. Am J Surg. 2001 Jun;181(6):567-70. for a description of the experience of a group of Italian physicians with video-guided minimally invasive surgery. For a related report, see Minimally invasive open thyroidectomy. Surg Today. 2001;31(8):665-9. There is insufficient experience to date that will allow a prediction of whether this will prove to be a real advance over conventional thyroidectomy. See Comparison between minimally invasive video-assisted thyroidectomy and conventional thyroidectomy: A prospective randomized study. Surgery. 2001 Dec;130(6):1039-1043.
My biopsy shows cells compatible with a follicular lesion. Should I have a subtotal thyroidectomy, or should I have half the thyroid removed, with a decision on more extensive surgery made at the time of quick section during the operation?
This is a controversial area, and the answer will differ between various surgeons and pathologists. Some patients will elect to have a less extensive initial operation, with the realization that a second operation, if thyroid cancer is the final pathological diagnosis, may be necessary in about 25% of all cases. Other patients may not want to face the prospect of a second surgical procedure, and elect to have a more extensive subtotal thyroidectomy done at the time of initial surgery. For studies that address this issue, see Randomized prospective evaluation of frozen-section analysis for follicular neoplasms of the thyroid. Ann Surg. 2001 May;233(5):716-22; The utility of routine frozen section examination for intraoperative diagnosis of thyroid cancer. Am J Surg. 1996 Dec;172(6):658-61; Follicular and Hurthle cell thyroid neoplasms. Is frozen-section evaluation worthwhile? Arch Surg. 1997 Jun;132(6):674-8; discussion 678-80 and The advantage of total thyroidectomy to avoid reoperation for incidental thyroid cancer in multinodular goiter. Arch Surg. 2004 Feb;139(2):179-82. and Hemithyroidectomy: The Optimal Initial Surgical Approach for Individuals Undergoing Surgery for a Cytological Diagnosis of Follicular Neoplasm. Ann Surg Oncol. 2006 Jan 30; [Epub ahead of print]
A review of these and other studies shows that completely different conclusions can be drawn about the utility of frozen section in the management of thyroid cancer, hence it is difficult to make definitive conclusions that are generalizable to all patients and centers. Some centers advocate the use of frozen sections in making a decision about proceeding to remove the whole thyroid, see The value of frozen section examinations in determining the extent of thyroid surgery in patients with indeterminate fine-needle aspiration cytology. Arch Otolaryngol Head Neck Surg. 2002 Mar;128(3):263-7, whereas other centers do not.
There are several studies that illustrate the low accuracy of information obtained from intraoperative analysis of the frozen section, hence patients should not be surprised to learn that the final pathology diagnosis differs markedly from the preliminary diagnosis obtained at frozen section, when dealing with a "follicular lesion", as outlined in Prevalence of cancer in follicular thyroid nodules: is there still a role for intraoperative frozen section analysis? Thyroid. 2003 Apr;13(4):389-94.
I am having surgery for Graves' Disease. Why can't the doctors freeze some of my thyroid tissue, and transplant it back later in case I become hypothyroid?
This interesting concept is being explored in some centers, but there is not sufficient experience or data to know whether this will prove feasible with good results and few complications. See Trial of autotransplantation of cryopreserved thyroid tissue for postoperative hypothyroidism in patients with Graves' disease. J Am Coll Surg. 2002 Jan;194(1):14-22.
I just found out I have thyroid cancer and I am pregnant-when should I have my surgery?
The answer to this question may be complex and should be individualized depending on the specific clinical circumstances. In general, patients with thyroid cancers confined to the thyroid may elect to wait till successful conclusion of the pregnancy before having an operation, generally without adverse consequences, as outlined in Outcome of differentiated thyroid cancer diagnosed in pregnant women. J Clin Endocrinol Metab. 1997 Sep;82(9):2862-6. Patients with larger tumors demonstrating progressive growth may decide to have surgery during pregnancy. These types of decisions should be made following a discussion of the risks for both the mother and the baby of operating during pregnancy, or after delivery of the baby. See Optimal timing of surgery in well-differentiated thyroid carcinoma detected during pregnancy. J Surg Oncol. 2005 Aug 23;91(3):199-203 and Management of differentiated thyroid cancer diagnosed during pregnancy. Eur J Endocrinol. 1999 May;140(5):404-6
My final pathology report shows vascular invasion of the tumor. What does this mean?
A finding that some thyroid cancer cells may be contained within blood vessels is not uncommon. This pathological finding is seen more frequently in patients with cancer spread to the lymph nodes, and may be associated with an increased risk of cancer recurrence, but vascular invasion does not appear to be a factor that influences survival, which is generally excellent in patients with well-differentiated thyroid cancer. See The clinicopathological significance of histologic vascular invasion in differentiated thyroid carcinoma. Am J Surg. 2002 Jan;183(1):80-6.
I had surgery and was found to have a 5 mm "incidental papillary carcinoma of the thyroid. What additional treatment do I need?
The answer to this type of question depends on the individual clinical setting, and unfortunately, there is little evidence from randomized trials to support clear treatment recommendations. Some centers would provide reassurance that additional aggressive treatment was not warranted, as very small lesions like this are rarely problematic. Indeed, small thyroid cancers are VERY common and may be found in 10-12% of patients having surgery for benign thyroid disease, as outlined in Incidental papillary carcinoma in patients treated surgically for benign thyroid diseases. Surgery. 2009 Dec;146(6):1099-104
Nevertheless, on very rare occasions, even very small tumors a few mm in size may spread outside the problems and act aggressively. There is intensive research interest in trying to identify which patients will do well (the majority) vs. the small minority of patients with a microcarcinoma that will present with more aggressive disease. For example, in the context of a research setting, measurement of circulating levels of peripheral blood thyroid-stimulating hormone receptor (TSHR) mRNA may provide useful information. Detection of circulating thyroid cancer cells in patients with thyroid microcarcinomas. Surgery. 2009 Dec;146(6):1081-9
The type of management appropriate in this setting should be discussed with your physician. Analysis of the small tumor for expression of the cyclin D1 protein may provide additional prognostic information, as outlined in Cyclin d1 protein expression predicts metastatic behavior in thyroid papillary microcarcinomas but is not associated with gene amplification. J Clin Endocrinol Metab. 2002 Apr;87(4):1810-3. Furthermore, in some select populations, microcarcinomas have been shown to be associated with a surprisingly high incidence of extrathyroidal extension and lymph node involvement Frequent, Aggressive Behaviors of Thyroid Microcarcinomas in Korean Patients. Endocr J. 2006 Aug 8; [Epub ahead of print]
I had surgery on my thyroid gland, and now I have damage to one of the nerves controlling my vocal cord. Can anything be done?
Occasionally, the nerve will gradually recover its function, depending on the extent of initial damage. There are also options for optimization of the position of the vocal cord, that can provide good symptomatic improvement in voice quality, as outlined in Current concepts in the management of unilateral recurrent laryngeal nerve paralysis after thyroid surgery. J Clin Endocrinol Metab. 2005 Feb 22.
I am worried about a low calcium level after surgery-can this be prevented?
The probability of developing hypocalcemia increases with the extent of the surgery. Some centers will try and prevent the development of hypocalcemia by routine administration of calcium and vitamin d supplements prior to the development of hypocalcemia. In the majority of patients, the calcium and vitamin D supplements can be reduced and often discontinued several weeks after the surgery. See Prevention of postoperative hypocalcemia with routine oral calcium and vitamin D supplements in patients with differentiated papillary thyroid carcinoma undergoing total thyroidectomy plus central neck dissection Cancer 2008 in press
Do I need a neck dissection as part of my thyroid cancer operation?
The answer depends in part on the size of your tumor, whether there is a concern that it may have spread to lymph nodes, and local surgical practice. This type of question, including the risks and benefits of central compartment exploration, is best discussed with your surgeon. Complications of central neck dissection in patients with papillary thyroid carcinoma: Results of a study on 1087 patients and review of the literature Thyroid. 2012 May 21. [Epub ahead of print]
This information is provided in conjunction with Dr. L. Rotstein, Staff Surgeon, University Health Network, Princess Margaret Hospital and Toronto General Hospital, University of Toronto.