The incidence of thyroid cancer has increased in recent decades, being responsible for
586,000 cases worldwide, ranking ninth in incidence in 2020. The rapid increase of
thyroid cancer, particularly papillary thyroid cancer, has been largely attributed to the
increasing use of ultrasound, along with increased use of other imaging modalities.
Similarly, analyzing the pattern of lymph node dissemination of well-differentiated
thyroid carcinoma, Eskander et al., 2 reviewed all the pertinent literature up to 2011 (a
total of 1,145 patients and 1,298 neck dissections) and reported an overall metastasis
rate in patients taken to to surgery of 53.1%, 15.5%, 70.5%, 66.3%, 7.9% and 21.5% in
levels IIa, IIb, III, IV, Va and Vb, respectively. For the Thus, the primary surgical
treatment for lateral neck disease generally includes lateral neck dissection in
conjunction with total thyroidectomy. Lymph node dissection should be performed in
patients with biopsy-proven metastatic lateral cervical nodes. Jugular nodes located at
levels II, III, and IV are the lateral neck compartments most commonly affected by CBDT
and should be included in all therapeutic lateral neck dissections. Level V, which
represents the posterior triangle of the neck, is affected less frequently. However, the
Vb level must be dissected along with the other levels, and careful visualization and
dissection of the spinal accessory nerve is paramount. Level V can be approached by an
anterior approach by retracting the sternocleidomastoid muscle posteriorly, or by
dissecting the posterior triangle behind the muscle sternocleidomastoid to the trapezius
muscle. The precise extent of the neck dissection is a decision made based on the volume
and location of the disease. The ATA recommends complete lymph node dissection (CLND),
including levels II and V, for most patients with clinically evident lateral neck
metastatic disease, although nuances regarding the extent of level V dissection are not
clarified, in relation to whether level V should be included. Regarding the difference
between the surgical techniques, the posterior approach to the sternocleidomastoid muscle
involves a longer incision, where the dissection proceeds from the anterior edge of the
trapezius muscle in a medial direction that includes the lymphatic contents of the
supraclavicular fossa. The upper margin of this area presents the greatest risk of damage
to the spinal accessory nerve. Furthermore, during the dissection of this region, several
supraclavicular branches of the cervical plexus can be found. Some branches of the deep
cervical plexus follow a course similar to that of the accessory nerve and may confuse
the novice surgeon. In the case of the anterior approach, the incision is made up to the
anterior edge of the ECM and once the accessory nerve has been identified at its
insertion in the sternocleidomastoid, its course is traced superiorly to the posterior
belly of the digastric. However, the effect of the anterior approach on the lymph node
count and the risk of future recurrence at level V is uncertain. With these differences
in terms of the approach in these two techniques, a greater length of skin incision, and
greater dissection of the accessory nerve can be observed. and of the deep cervical
plexus given the similar course to the XI nerve in the posterior approach, the question
arises as to whether the surgical approach influences the patient's morbidity.
The main objective of the present study was to compare the morbidity and effectiveness
measured in terms of lymph node count of emptying levels II to V by the anterior versus
the posterior route in patients with well-differentiated thyroid cancer with lateral
metastases.