Indications and Classical surgical approaches to RG
Classical indications for surgically removing a simple/non-toxic goiter
date back to the beginning of the twentieth century: relief from
compression symptoms, prevention of or suspicion of an associated
malignancy, or for cosmetic purposes51. Unfortunately,
these criteria are somehow vague and, because ultimately the surgeon is
the sole responsible for the outcomes of thyroidectomy, in 2018 a
“Choosing wisely” initiative from Germany proposed more reproducible
criteria: compression symptoms (dyspnea, stridor, dysphagia) must be
directly attributable to goiter while a reasonable suspicion of
malignancy must be documented (i.e. , TI-RADS category 4c/ 5, Tir
3 or higher class at FNAC in the presence of risk factors for thyroid
cancer, basal calcitonin serum level increase >26 pmol/L in
women and 60 pmol/L in men, cN+ status at ultrasound). In the absence of
the above, surgery may also be indicated for “prevention of
complications” that may derive from a progressive RG (defined as
tracheal compression >35%, superior vena cava
syndrome)”52–54. Again the progression must be
documented but the very natural history of untreated RG is still poorly
understood2.
An exhaustive explanation to the patient and their caregivers is the key
to surgical success3. A detailed technical overview of
the classical surgical approaches to RG has been recently given by
Uludag et al and it will briefly be discussed here39.
A Kocher incision, ligation of the superior and inferior vascular
peduncles, and digital dissection remain the standard surgical steps,
but resection of the pre-laryngeal musculature is often necessary for
delivering large goiters. A 2022 study has for the first time evaluated
its consequences on vocal and swallowing function: by using
patient-reported impairment scores, a prospective head-to-head study of
34 patients revealed no significant differences when strap muscles are
transected or not55.
In 2021, the International Neural Monitoring Study Group (INMSG)
published the most important study of surgical anatomy since the
introduction of intraoperative neuromonitoring (IONM). The authors have
meticulously evaluated the course and anatomical relationships of 1000
RLNs: strikingly, among other findings, it emerged that in 50% of cases
of RG (versus 30% in standard thyroidectomies), the RLN was fixed,
splayed, or entrapped at the level of the capsule of the thyroid, thus
rendering at high risk for loss of signal56. IONM is
thus mandatory for every RG operation and, in the case of “giant” RG,
many authors suggest the upfront use of a transcervical medial approach,
which implies the separation of the isthmus and dissection of Berry’s
ligament in a layered fashion along the trachea and towards the RLN. In
a series from the USA, successful identification of the RLN was reported
to be 84% with this approach and postoperative vocal cord dysfunction
(assessed by flexible laryngoscopy) was null57. A very
high rate (17%) of postoperative hematoma was reported, yet the authors
declared that revision in the operative room was deemed necessary only
for one patient57. Another larger case series from
Greece declared instead no postoperative bleeding, and a permanent RLN
damage rate comparable with classic lateral
approaches58.
Regarding the extent of the resection, even in the most recent series
total thyroidectomy is the preferred strategy for RG, which however can
harbor one or more foci of malignancy in up to 40% of
cases21. When the intrathoracic part is well
lateralized, or there are anatomical constraints or technical issues
during the dissection, a subtotal resection or a simple
hemithyroidectomy may help relieve the compression symptoms while
minimizing the postoperative complications. New technologies are being
exploited also in this type of operation: in 2018, some authors have
proposed a microdebrider-assisted intracapsular reduction thyroidectomy
on a small series of 26 patients. According to the proponents, a
standard sinus suction debrider may morcellate the intracapsular part of
the RG, it has no effect on the risk of major bleeding, and may avoid
the need for sternotomy in selected patients59.
Instead, recent retrospective papers on transoral endoscopic
thyroidectomy vestibular approach (TOETVA) or transoral robotic
thyroidectomy (TORT) consider RG as an exclusion criterion because of
intrinsic limitations in terms of surgical exposure60.