Surgical Treatment of Substernal Goiter Part 2: Cervical and Extracervical Approaches, Complications

The most appropriate treatment of substernal goiter (SG) is surgery. These patients should be evaluated carefully and multidisciplinary in pre-operative period and surgical management should be planned preoperatively. Although most of the SGs can be resected by the cervical approach, an extracervical approach may be required in a small proportion of patients. Surgical complications of SG related to thyroidectomy are higher than other thyroidectomies. In addition to the complications related to thyroidectomy, complications related to the type of surgical intervention may also occur in SG. The patients who may be needed extracervical approaches should be consulted with thorax surgeons, cardiovascular surgeons, and anesthesiologists preoperatively; the surgical management should be planned together. In this part, we aimed to evaluate the cervical approach methods, extracervical approach methods, technical details, and complications in detail.

Preoperative Evaluation of Substernal Goiter by Computed Tomography in the Extended Neck Position

Sternotomy is indicated when a goiter cannot be resected via a cervical incision, such as in the case of a substernal goiter extending beyond the aortic arch. In this article, we report a case of a large substernal goiter that was successfully removed using the cervical approach only. This is a case of a 68-year-old woman, diagnosed with goiter 20 years ago, who complained of a neck mass enlargement with associated cough. Pathological examination revealed no malignancy. Computed tomography (CT) scan showed an 11-cm thyroid mass reaching the level of the aortic arch. Preoperatively, we evaluated the substernal extent of the goiter via CT in the extended neck position to decide whether sternotomy was necessary. With the patient's neck extended, the goiter withdraws cranially above the aortic arch. The mass was then removed via the cervical approach without sternotomy. Preoperative CT in the extended neck position was thus deemed helpful in deciding whether or not sternotomy was required.

Estimation of Chest Wall Attenuation of the Emissions from Iodine-123 in the Instance of Substernal Goiter: A Phantom Study

Objective: The underestimation of thyroid uptake measurements with iodine isotopes has been a generally accepted theory in patients with substernal goiter due to attenuation by the chest wall. The extent of this underestimation is not well known. In this study, we calculate the attenuation of the emissions from iodine-123 utilizing a cadaver chest wall with a thyroid probe in order to better understand the potential severity of this underestimation. Methods: A capsule of 11.1 Megabequerels (MBq) of iodine-123 was measured using a thyroid probe directly, in a standard neck phantom and behind a cadaveric chest wall that included the soft tissues and bony structures (sternum). Results: Using the thyroid probe, the calculated attenuation of the iodine capsule by the neck phantom was 18% and by the chest wall was 35%. Conclusion: Thyroid uptake in the case of substernal goiter may be underestimated by standard techniques using a neck phantom. The composition of the chest wall can vary greatly and substernal extent of the goiter would be difficult to calculate with a high level of accuracy on a routine basis. Direct comparison with a cadaveric specimen leads to similar issues but does give us a rough estimation of the extent of this issue. This study suggests that the attenuation by the chest wall can be substantial. Knowledge of the extent of the substernal component of the thyroid gland may be useful if the uptake measurement is used to calculate doses for the treatment of hyperthyroidism in patients with a substernal goiter.

Twenty-two years of experience in diagnosis and management of substernal goiters

OBJECTIVE

Descending goiter has been a focus of controversy in thyroid surgery until nowadays. This study aims to investigate the diagnosis and treatment options of thyroid goiters extending into the mediastinum and the thoracic cavity.

METHODS AND MATERIALS

A retrospective study was conducted assessing all cases of substernal goiter managed in a tertiary care referral center within 22 years. Demographics, clinical, operative, anatomical, and pathological data of the patients were recorded and analyzed.

RESULTS

Among 3.028 total thyroidectomies, 212 procedures for substernal goiters were studied. All cases underwent total thyroidectomy. The surgical approach was cervical in all but two cases. A very low rate of complications and zero mortality were noted. Incidence of malignancy on permanent histology was 16%.

CONCLUSION

Descending goiter constitutes a major indication for thyroid surgery. The overwhelming majority of descending goiters may be managed surgically through a neck incision. In experienced hands good results with low morbidity should be expected. Such cases should be considered as challenging, however, and therefore management in a referral center may be necessary in order to ensure optimal results.

Morbidity of total thyroidectomy for substernal goiter: A series of 70 patients

Total thyroidectomy for substernal goiter occasionally requires a sternotomy associated with a cervical incision. We sought to analyze the postoperative complications of thyroidectomy for substernal goiters in our center and more precisely the complications related to the sternotomy. All patients who underwent total thyroidectomy for substernal goiter in our center between 2007 and 2016 were reviewed retrospectively. Patients with combined cervical incision and sternotomy (ST group, n=16) were compared to those with cervical incision alone (CT group, n=54), with regard to postoperative complications. Risk factors for the occurrence of postoperative complications were investigated in this population. A total of 24 patients (34.2%) had one or more postoperative complications. The incidence of transient hypoparathyroidism and recurrent laryngeal nerve injury were higher in the ST group (P=0.001 and P=0.052, respectively). The median duration of hospitalization was longer in the ST group (P<0.001). Eighteen patients (25.8%) had a malignant tumor on final pathology. In univariate analysis, the following risk factors for transient postoperative hypoparathyroidism were identified: sternotomy, preoperative symptomatic character and thyroid height (P=0.001, P=0.009 and P=0.013, respectively). In multivariable analysis, only sternotomy was an independent risk factor for postoperative transient hypoparathyroidism (OR=4.48 [1.1; 18], P=0.035). Sternotomy is associated with added morbidity that is not negligible. This surgical approach should be reserved for substernal goiters that descend into the posterior mediastinum, below the level of the aortic arch, when there is suspicion of carcinoma with loco-regional invasion, or when the thyroid tissue is located mainly intrathoracically (conical shaped thyroid, asymptomatic goiter, ectopic thyroid).

Report of a case and review of sternotomy indications

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Substernal goiter definition is controversial, while they are generally defined as goiters which at least 50% of the thyroid mass extends bellow the thoracic inlet.

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Our patient had a massive substernal multinodular goiter, the left lobe of which caused compression of the braciocephalic vein with symptoms from his left upper extremity.

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The massive size of the gland along with the strict adhesion of the isthmus and left thyroid lobe to the brachiocephalic vein led to the decision of performing a median sternotomy.

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Despite the extensive procedure, patient recovery was uneventful.

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The lack of a uniform definition on substernal goiter and the diversity of thoracotomy indications, lead to a patient-tailored surgical approach. Still the execution of thoracotomy is considered safe in the hands of an experienced surgeon.

Introduction

Substernal goiters are characterized by the protrusion of at least 50% of the thyroid mass below the level of the thoracic inlet. Still their definition is controversial.

Case presentation

The case refers to a 44 year old male who presented to our department due to swelling and a feeling of ‘heaviness’ of his left upper extremity for the past 6 months. CT scan revealed a massive substernal goiter extending to the great vessels. Intraoperatively, a median sternotomy was performed due to the size of the gland and the close adhesion of the isthmus and lower left thyroid lobe to the brachiocephalic vein. Resection of the gland revealed the vein to have a cord-like shape, leading to reduced venous return and upper extremity symptoms. Recovery was uneventful for the patient who was discharged on the 7th postoperative day.

Discussion

While most substernal goiters can be surgically managed through a cervical incision, there are cases in which a median sternotomy is indicated. Those cases include excessive gland size, thoracic pain, ectopic thyroid tissue and the extent of the goiter to the aortic arch. Median sternotomy is associated with a number of intra and postoperative complications, although when performed by an experienced surgeon, mortality and morbidity rates along with long-term recovery are not affected.

Conclussion

The lack of a uniform definition and variety of indications, lead to a patient-tailored approach regarding the execution of sternotomy during surgical management of massive substernal goiters.

Surgical treatment of substernal goiter: An analysis of 44 cases

OBJECTIVE

Substernal goiters are classified as primary or secondary intrathoracic goiters. Here, we report the diagnosis, symptoms, treatment, and postoperative complications of 44 substernal goiters (2 primary mediastinal goiter and 42 secondary mediastinal goiters).

METHODS

A retrospective chart review of 351 patients undergoing thyroidectomy at the Department of Otolaryngology-Head and Neck Surgery of the Tokyo Metropolitan Tama Medical Center. Between 2009 and 2015, 44 patients underwent surgery for substernal goiter.

RESULTS

The frequency of primary and secondary mediastinal goiters was 0.5% and 11.9%, respectively. The preoperative symptoms were neck mass, dyspnea, and dysphagia. Eight patients were asymptomatic. Thirty-nine patients had benign masses and 5 patients had malignant masses. Most patients were operated on for adenomatous goiters (52.2%). In ten cases beyond the aortic arch, the tumors were benign and there were eight cases of adenomatous goiter. All patients underwent a successful transcervical incision without sternotomy. Even the primary intrathoracic goiters were extracted after total thyroidectomy via the cervical approach without complications. Although one case showed unilateral recurrent nerve paralysis as a postoperative complication, phonetic function improved in 6 postoperative months. No instances of postoperative bleeding or definitive hypoparathyroidism occurred, and tracheostomy was not performed in any of the cases.

CONCLUSION

The cervical approach was safely performed in almost all substernal goiters without an extracervical procedure. Selected cases of primary mediastinal goiter may be excised via the cervical approach.

Demographics, disparities, and outcomes in substernal goiters in the United States

BACKGROUND

Disparities distinguishing patients with substernal goiters from nonsubsternal goiters have not been thoroughly described.

METHODS

The National Inpatient Sample database was used to compare patients who underwent substernal thyroidectomy years 2000 to 2010 with those who underwent thyroidectomy for nonsubsternal goiter.

RESULTS

A total of 110,889 patients underwent thyroidectomy for goiter (5,525 substernal and 105,364 nonsubsternal). Substernal thyroidectomy patients were older, more likely to be Black or Hispanic and to have Medicare insurance. They had a higher comorbidity index, were more likely to be admitted emergently and to have postoperative complications such as hemorrhage/hematoma, pneumothorax, pulmonary embolism, and hypocalcemia/hypoparathyroidism. Furthermore, substernal thyroidectomy patients had 73% increased odds of death during admission than nonsubsternal thyroidectomy patients.

CONCLUSIONS

Substernal goiters present a distinct type of goiter with identifiable patient-level characteristics and an increased risk of postoperative complications and death. Earlier identification and treatment of goiters may allow earlier interventions at a stage when risks are reduced.

Substernal goiter: when is a sternotomy required?

BACKGROUND

Sternotomy for substernal goiters (SSG) is associated with greater morbidity than a cervical approach to thyroidectomy. We sought to identify predictors for sternotomy as a surgical approach for the removal of SSG and analyzed the preoperative and postoperative characteristics of patients with SSG compared with those with large goiters contained entirely within the neck or a cervical goiter.

METHODS

A retrospective review of a surgical database was performed. We included patients with large (>100 g) thyroids or SSG, regardless of size. Between 1995 and 2013, 220 patients met these criteria. Comparisons were made between patients who had an SSG and patients who had a cervical goiter with particular focus on those who required sternotomy.

RESULTS

Of the 220 patients, 127 patients (58%) had SSG, of whom 7 (5.5%) required sternotomy. All patients who underwent sternotomy underwent preoperative computed tomography scanning and were more likely to have preoperative symptoms of chest pressure and voice complaints and have extension of the thyroid gland below the aortic arch. Sternotomy took an average of 2 hours longer than a cervical incision, was associated with significantly more blood loss (600 versus 190 mL, P = 0.04), and a longer length of stay (3.1 versus 1.8 d, P = 0.03) than cervical thyroidectomy.

CONCLUSIONS

Sternotomy for SSG is rare. All patients necessitating sternotomy had extension below the aortic arch and were more likely to present complaining of chest pressure and voice issues.

Myasthenic Crisis Manifesting as Postoperative Respiratory Failure following Resection of Unsuspected Intrathoracic Thymic T-Cell Lymphoma during Thyroidectomy for an Adjacent Large Retrosternal Goiter

A middle-aged female with a goiter of 10 years' duration presented with progressive pressure symptoms, nocturnal choking and dyspnea on exertion for 5 months. Physical examination demonstrated a large simple multinodular goiter. Imaging revealed a deep retrosternal goiter extending below the tracheal bifurcation with marked tracheal deviation. Total thyroidectomy was carried out via a cervical approach and a median sternotomy. Extubation was not possible, and the patient had to be kept intubated. She then went into a myasthenic crisis. Initial ventilatory support was followed by intravenous immunoglobulin, steroids and pyridostigmine. The patient had complete remission and was asymptomatic 18 months later. Histopathology showed a T-cell-rich thymoma in addition to a nodular colloid goiter.

Substernal goiter: when is a sternotomy required?

The presence of substernal goiter is, per se, an indication for surgical management. Surgical approach of substernal goiter can most commonly be performed using the cervical access, but at times, a sternotomy or thoracotomy is necessary. The aim of this study was to identify the preoperative predictors of a sternotomy in the management of substernal goiter in order to provide better preoperative planning and patient consent. Between 2005 and 2012, 665 patients were referred to our clinic for thyroidectomy, 42 patients (6.3%) had substernal goiter and were included in this study. All substernal goiters were treated surgically, 38 (90.5%) by a cervical approach and 4 (9.5%) by full median sternotomy. All surgeries were successful, with no major postoperative complications. Minor postoperative complications of transient hypocalcemia and transient paralysis of the recurrent laryngeal nerve occurred in 5 (11.9%) and 2 (4.7%) cases, respectively. Indication of median sternotomy was as follows: extension of goiter below the aortic arch, large thyroid tissue extending towards tracheal bifurcation, and ectopic thyroid tissue in the mediastinum. Substernal goiter can be removed through a cervical incision, but on rare occasions, a median sternotomy may be required.

Surgical treatment of large substernal thyroid goiter: analysis of 12 patients

This study was carried out to evaluate the clinical presentation, surgical treatment, complications, and risk of malignancy for large substernal goiter. From March 2010 to December 2012, 12 patients with large substernal thyroid goiter who underwent surgery in our Department were enrolled in the study. Their medical records were retrospectively analyzed. Collar-shaped incision was adequate for resection of the lesions in 10 (83%) patients, while two (17%) patients required combined cervical-thoracic incision. In addition, one case was subjected to postoperative tracheotomy. Transient hypocalcaemia occurred in one case. The incidence of transient hoarseness, tracheomalacia and hypothyroidism was 8.3%. There was no perioperative bleeding, thyroid storm as well as other serious complications. All patients were clinically cured. Therefore, cervical collar incision is nearly always adequate for most cases of larger substernal goiter, and sternotomy can be avoided. Furthermore, the application of intraoperative ultrasonic knife can effectively reduce intraoperative and postoperative complications. Aggressive perioperative management is crucial for the successful removal of large substernal goiter.