Transcervical and robotic-assisted thoracoscopic resection of a substernal goiter
- 1 Department of Otolaryngology-Head and Neck Surgery, Robert Wood Johnson University Hospital, New Brunswick, New Jersey, USA
- 2 Department of Surgery, Robert Wood Johnson University Hospital, New Brunswick, New Jersey, USA
- Correspondence to Dr Neha Wadhavkar; nmw76@rutgers.edu
Abstract
Several genetic and environmental factors contribute to the development of multinodular goitre. A transcervical surgical resection is recommended for larger goitres, though a minority of cases may require sternotomy or thoracotomy. We present a case of a posterior substernal goitre that was resected with combined transcervical and robotically assisted thoracic approaches. A woman in her 30s with an enlarging thyroid goitre elected to proceed with surgical resection. CT imaging demonstrated significant extension of the goitre into the posterior mediastinum and a staged approach was decided on. Both the initial transcervical thyroidectomy and the subsequent robotically assisted resection of the mediastinal portion were successful, without major complications. While most substernal goitres can be resected transcervically, certain rare anatomic features, such as extension into the posterior mediastinum, warrant consideration of a thoracic approach. Specifically, a robotic-assisted resection poses several advantages over traditional, more invasive approaches.
Background
Multinodular goitre of the thyroid gland is a relatively common condition that disproportionately affects women compared with men.1 Genetic and environmental factors in combination with an aberrant cyclic pattern of chronic low-grade stimulation of the thyroid gland result in eventual hyperplasia and subsequent nodular growth.1
Surgery offers definitive treatment and is recommended in patients with substernal extension or compressive symptoms.2 The majority of cases can be removed transcervically, while a minority require thoracic approaches. Sternotomy is typically performed for anterior substernal goitres, while thoracotomy may be required for those extending into the posterior mediastinum.2–4 Despite increasing use of minimally invasive surgery, there is limited information on its use in substernal goitre.3
We present a case of a patient with a posterior substernal goitre with extension beyond the tracheal bifurcation that was successfully resected with combined transcervical and robotically assisted thoracic approaches.
Case presentation
A woman in her 30s presented with reports of dysphagia and an enlarging multinodular goitre that progressed over 4 years. She did not report any symptoms of hypothyroidism or hyperthyroidism or other compressive symptoms, such as dyspnoea, wheezing or hoarseness. She reported no family history of thyroid disease, no prior surgeries and no prior radiation treatment. Thyroid ultrasound obtained 4 years prior reported a multinodular goitre with a 7 cm left lobe and a 5 cm right lobe, though the ultrasound view was limited given the substernal extension of the goitre. Fine-needle aspiration at that time was benign. Given the dysphagia and bothersome appearance, the patient elected to proceed with surgery.
Investigations
CT imaging illustrated extension of the left thyroid lobe from the sternum to the submandibular gland and significant substernal extension of the right thyroid lobe into the posterior mediastinum, beyond the tracheal bifurcation (figures 1–2). This appearance raised concern that the goitre may be undeliverable transcervically. The patient opted for a staged procedure as opposed to delaying the surgery until cardiothoracic surgery assistance was available.
Sagittal view of the thyroid goitre demonstrating significant substernal extension into the posterior mediastinum.
Coronal view of the thyroid goitre demonstrating the cervical and mediastinal components.
Treatment
The left thyroid lobectomy was uneventful and the patient was discharged on postoperative day 1. On follow-up, bilateral vocal cord mobility was confirmed with flexible laryngoscopy. The patient returned 6 weeks later for the completion thyroidectomy, with robotic-assisted resection of the mediastinal portion. The procedure began with removal of the cervical portion of the goitre via the prior incision. The recurrent laryngeal nerve was identified and preserved. At this point, it was confirmed that the cervical portion was anatomically separated from the mediastinal portion, indicating a separate mediastinal blood supply. Following establishment of single left lung ventilation and fiberoptic bronchoscopy, cardiothoracic surgery proceeded with robotic-assisted thoracoscopic resection of the mediastinal portion using the Da Vinci Xi platform. The mass was carefully freed from the adjacent mediastinal structures. Three feeding arteries and four large draining veins were ligated. A port site incision was enlarged for removal of the 10 cm mediastinal mass. On postoperative day 1, she experienced mild stridor that resolved with dexamethasone and nebulised epinephrine and her chest tube that was placed for drainage was removed.
Outcome and follow-up
Her stay was otherwise uneventful and she was discharged on postoperative day 2. Her pain was controlled with over-the-counter analgesics and she subjectively had a normal voice at her postoperative appointment, so a repeat laryngoscopy was not performed. Her chest X-ray 1 month later was unremarkable. Final pathology was consistent with benign thyroid goitre.
Discussion
Lack of a unified definition for substernal extension of multinodular goitre contributes to the variation in reported prevalence of the condition. The American Thyroid Association defines substernal goitre as extension past the sternal notch with the patient in the supine position, detected either radiologically or clinically.2 Substernal goitres can be classified based on the suspected origin of the thyroid tissue as well as their location in the mediastinum.3
Primary intrathoracic goitres represent a separation of thyroid blastoma from the thyroid primordium, which is pulled into the thoracic cavity by descent of the heart and great vessels. These are rare, composing <1% of substernal goitres, and often have an independent mediastinal blood supply.3
Several authors have reported clinical predictors of the need for a thoracic approach to remove substernal goitres, including: growth beyond the tracheal bifurcation or aortic arch, posterior mediastinal growth pattern, isolated mediastinal goitres or a dumbbell shape.2–4 Existing literature on surgically treated substernal goitres consists almost exclusively of patients undergoing open approaches, despite increasing use of minimally invasive techniques in other settings.3 4
Video-assisted thoracoscopic surgery (VATS) and, more recently, robotic-assisted thoracoscopic surgery (RATS) have been associated with reduced hospital length of stay, improved pain and quicker recovery compared with open approaches.5 Proponents of RATS have argued that it provides multiple clinical advantages over VATS including: improved visualisation, ergonomics, manoeuvrability, motion-scaling and tremor filtering, as well as a shorter learning curve.5
We present a unique case of a young woman with a substernal goitre whose imaging displayed multiple features associated with requiring a thoracic approach: extension beyond the tracheal bifurcation, location in the posterior mediastinum, and, most importantly, anatomic discontinuity of the mediastinal portion from the cervical goitre. As a result, preparations were made for a robotic-assisted thoracic approach. Ultimately, her goitre had multiple feeding vessels in the mediastinum that were safely ligated under direct visualisation. Failure to identify the rare goitres with a mediastinal blood supply can result in substantial haemorrhage during blind transcervical delivery that may require emergent conversion to an open thoracic approach. RATS requires an experienced surgeon and advanced planning for equipment set-up but provides numerous clinical and functional advantages to patients described above.
Certainly, the majority of substernal goitres can be safely removed transcervically, and a partial sternotomy may be more appropriate for those with significant anterior extension that cannot be delivered via the neck. However, for goitres with significant posterior mediastinal extension or substernal goitres with a suspected mediastinal blood supply, a planned robotic approach provides numerous clinical and functional advantages, exemplified by this case.
Learning points
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Substernal goitres with a mediastinal blood supply are relatively rare among multinodular thyroid goitres.
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The majority of substernal goitres can be resected transcervically. However, certain rare and challenging anatomic features, such as extension into the posterior mediastinum, warrant consideration of a combined transcervical and thoracic approach.
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A robotic-assisted thoracic resection poses several advantages over traditional, more invasive open approaches.
Ethics statements
Patient consent for publication
Footnotes
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Contributors NW: writing of original draft, editing and reviewing. IK: editing and reviewing. CB: conceptualisation and design, writing of original draft, editing, reviewing and supervision.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
References
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