الفهرس 
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Abstract
Retrosternal goiter was first described by Albrecht von
Haller in 1749, as the extension of the thyroid tissue below the
upper opening of the chest. The definition of Retrosternal
goiter is still not uniform, and varies between the different
Authors. However, the most commonly accepted definition of
Retrosternal goiter describes a goiter as retrosternal when a ≥
50% portion of the mass is located in the mediastinum.
(Netterville et al., 1998).
Diagnosis of Retrosternal goiter is most frequently made
in the fifth or sixth decade of life, with a female/male rate of
4:1. retrosternal goiters can be classified as either primary or
secondary. Primary intra-thoracic goiters arise from aberrant
thyroid tissue which is ectopically located in the mediastinum,
receive their blood supply from mediastinal vessels and are not
connected to the cervical thyroid. They are rare, representing
less than 1% of all retrosternal goiters. (Wu et al., 2006).
Secondary retrosternal goiters develop from the thyroid
located in its normal cervical site. Downward migration of the
thyroid into the mediastinum is facilitated by negative intrathoracic
pressure, gravity, traction forces during swallowing
and the presence of anatomical barriers preventing the
Summary
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enlargement in other directions (thyroid cartilage, vertebral
bodies, strap muscles, especially in patients with a short neck).
These secondary retrosternal goiters are, characteristically, in
continuity with the cervical portion of the gland and receive
their blood supply, depending on cervical vessels, almost
always through branches of the inferior thyroid artery. (Shen
et al., 2004).
The most common symptoms are related to compression
of the airways and the esophagus, and are represented by
dyspnoea, choking, inability to sleep comfortably, dysphagia
and hoarseness. Less commonly, signs of compression of
vascular and nervous structures are present, such as superior
vena cava obstruction (superior vena cava syndrome) and/or
Horner’s syndrome (compression of sympathetic chain). The
diagnosis of retrosternal goiter is based upon clinical history,
clinical examinations, and imaging findings. (Mackle et al.,
2007).
Computed tomography (CT) scanning is, at present the
most exhaustive examination for assessment of the extent of
the goiter and compression effects on adjacent anatomical
structures. (Grainger et al., 2005).
Most retrosternal goiters can be removed through a
cervical approach, while a partial or total sternotomy should be
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performed only in a minority of patients, ranging between 1-
11%.(Hedayati and McHenry, 2002).
There is an alternative and less invasive technique
combining video-assisted thoracoscopic surgery (VATS) with
a supraclavicular approach. This technique seems to offer
improved exposure and reliable control of the neuro-vascular
structures in the anterior mediastinum when resecting a huge
retrosternal goiter that may prevent nerve injury. (Shigemura
et al., 2005).
The desire to find a minimally invasive approach to
posterior mediastinal tumors stems from increasing evidence
that thoracoscopic surgery is associated with quicker recovery
and less morbidity than open surgery. (Whitson et al., 2007).
The Da Vinci robotic technology offers a novel
minimally invasive approach to retrosternal goiters extending
into the posterior mediastinum. It appears to be safe and, like
VATS, may offer an advantage over an open thoracic
approach. Further studies will be required to define its precise
role in thyroid surgery. (Augustin et al., 2006).