Thyroid and Parathyroid

muscle (Fig. 36-31). The superior pole vessels are then individually identified,
. skeletonized, and doubly ligated low on the thyroid gland
When the superior pole vessels have been ligated and divided, the tissues
posterolateral to the superior pole can be swept away from the thyroid gland in a
posteromedial direction. The direction is important because it reduces the chances of
damaging the vessels supplying the upper parathyroid glands. The recurrent laryngeal
nerves enter the larynx at the level of the cricoid cartilage, passing under or through
.( Berry's ligament and entering the larynx deep to the cricothyroid muscle (Fig. 36-32
At this point it should be possible to identify the upper parathyroid gland. The upper
gland usually is situated at the level of the cricoid cartilage. The lower parathyroid
gland is found most commonly just below where the inferior thyroid artery and
recurrent laryngeal nerve cross. In approximately 80 percent of patients the glands are
located within 1 cm of the artery. The lower parathyroid gland usually is situated
anterior to the recurrent laryngeal nerve, and when it is not, it is usually located in the
.( thymus or in parathymic fat (Fig. 36-33
The thyroid is completely mobilized by gently sweeping dorsally all tissue along the
posterolateral border away from the thyroid. All vessels are ligated and divided on the
thyroid capsule to minimize the possibility of devascularizing the parathyroids. No
tissue should be clamped or divided that might be or contain a recurrent laryngeal
. nerve
Parathyroids that are ischemic, or are situated very anteriorly on the thyroid gland, or
have been removed along with the thyroid lobe, should be examined after removal.
They should be biopsied and confirmed by frozen- section examination, minced into
1-mm cubed pieces, and implanted into a small pocket in the ipsilateral sternohyoid
. muscle, with a silk suture or clip marking the site
The recurrent laryngeal nerves should be identified; the nerve is located more
medially on the left and runs more obliquely on the right. The most difficult part of
the operation usually is during the dissection where the recurrent nerve passes through
Berry's ligament. It is here that the nerve is in close proximity to the thyroid, tethered
down by the ligament, through which runs a small artery, and it is here that the nerve
is most commonly injured. If bleeding occurs at this site it should be controlled by
gentle pressure before identification of the nerve to avoid injury, and then the vessels
. are all ligated. Use of electrocautery to control bleeding should be strictly avoided
A pyramidal lobe is present in about 80 percent of patients and should be dissected
free superiorly to the level of the thyroid cartilage or higher and removed in continuity
with the thyroid lobe and the isthmus. One or more lymph nodes are often present just
cephalad to the isthmus of the thyroid gland (Delphian node) and should be removed
. with the thyroid
When lobectomy is performed, the isthmus is divided flush with the contralateral
gland and oversewn. When total thyroidectomy is performed, the same procedure is
followed on the contralateral side. If a subtotal thyroidectomy is being performed (for
Graves' disease or multinodular goiter), normal practice is to perform a total
lobectomy on one side and a subtotal lobectomy on the other side. Removing all