Management of substernal goiter UCH KH Tse Clinical

Management of substernal goiter UCH KH Tse

Clinical scenario • 70/F • Asymptomatic. • Refer for your expert opinion.

Questions What is the diagnosis ? How do you manage ?

Introduction • SSG • First described by Haller in 1749. • Account for 10 -15% of all the mediastinal mass. • SSG / All thyroidectomy = 2. 6 -20% Madjar Chest 1995

Definition • Confused. 1. Decend inferior to the thoracic inlet. Katlic et al Am J Surg 1998 2. >50% thyroid mass inside thorax. Wax et al J Otolaryngol 1992 Arici et al Int Surg 2001 3. Goitres extend to 4 th thoracic vertebra. Lindskog and Goldenberg JAMA 1957

Anatomy SSG classified into two groups. 1. Truly intrathoracic or aberrant goiter (1%). • Congenital • Blood supply derived from the intrathoracic vessel entirely. • No connection to the cervical thyroid gland. Lahey & Swinton et al 1934

Anatomy 2. Arises in the cervical thyroid gland • Acquired. • Decends along a fascial plane through the thoracic inlet to the mediastinum. Lahey & Swinton et al 1934

Anatomy Anatomical constrain. Downward traction

Symptomatology • Neck mass, SOB, dysphagia. • 5 -50% can be asymptomatic on presentation. Katlic MR Am J Surg 1985 • Prolong course of symptoms. • From 2 weeks to 20 years with symptoms before referral. Mean = 31 months.

Rationale for operation 1. SSG is progressive, can result in sudden airway obstruction. Singh B Am J Otolaryngol 1994. 2. Inaccessible to, inaccurate, and dangerous biopsy. Rietz KA Acta Chir Scand 1960 3. Long history MNG does not preclude malignancy, hyperfunction or complication. Malignancy in 7 -17% Sanders Arch Surg 1992 Torre G Am Surg 1995

Rationale for operation 4. No effective alternative treatment. I 131? T 4? Allo MD Surgery 1983 5. Less operative complication in the asymptomatic patients. Para-Menbrives et al Internat Surg 2003 The consensus is that substernal goiter is best managed surgically. Katlic MR Am J Surg 1985

Investigation CT neck and thorax is the most valuable. Netterville et tal Laryngoscope 1998 Sanders LE Arch Surg 1992 1. Outline the extent of thyromegaly. 2. Differentiate the origin of the goiter. 3. Measure the degree of narrowing of the trachea.

The operation 1. 2. 3. 4. 5. Head up, neck well extended. Wider and lower incision. Division of the strap muscles. Control cervical blood supply first. Excise the opposite lobe first, to provide more room in the neck. Wheeler M. H. et al BJS 1999 • Sternotomy rate 2 -11. 7 % Michel LA Br J Surg 1988

The operation No Progress Manubrinectomy Claviclectomy Median sternotomy/ Limited sternotomy

Sternotomy

The operation Other indications for sternotomy / thoracotomy 1. Intra thoracic goitre / ectopic goitre. 2. Vasoagressive signs. 3. Retroesophageal goiters. 4. Suspected malignancy, mediastinal lymphadenectomy. 5. After a prior cervical thyroidectomy, with intra -thoracic recurrent.

Our study Retrospective study • From Jan 2000 to Dec 2003 • 287 cases of thyroidectomy. • 24 (8. 4%) were SSG • M: F = 5: 19 • Mean age 60. 1+/-15. 5 (26 - 90)

Symptoms in patients with substernal goitre Symptoms & signs SOB (including 3 cases of acute airway obstruction) Neck discomfort Dysphagia Hoarseness Asymptomatic Duration of symptoms 2 -120 months, mean 43. 3 +/- 47. 5 Number(%) 8(33. 3) 1(4. 2) 13(54. 2)

Histopathologic diagnoses of substernal goitre Diagnoses Number(%)

Morbidity of thyroidectomy for substernal goitre(N=24) Recurrent laryngeal nerve injury(nerve at risk) Transient hypoparathyroidism(patients at risk N=15) Permanent hypoparathyroidism Haematoma Wound infection Pneumonia Motality Number(%) 1(2. 7) 2(13. 3) 0 1(4. 2) 0

Comparison of complications between asymptomatic and symptomatic patients Complications Asymptomatic (13) Recurrent laryngeal nerve injury Transient hypoparathyroidism Haematoma Pneumonia Wound infection Fisher exact test, p=0. 033 Para-Menbrives et al Internat Surg 2003 0 1 0 0 0 Symptomatic (11) 1 1 1

Conclusion A substernal goiter is always indicated for resection and should be performed early, except the patient is unfit for operation.

Thank you

Asymptomatic(N=13) Symptomatic(N=11) p

Our study Reasons for more complication in the symptomatic group. 1. Patient is older. 2. More emergency operation. 3. May be a larger proportion of the goitre is intrathoracic.