Atlas of General Surgical Techniques (Courtney M. Townsend Jr., B. Mark Evers)
.pdf
ACKNOWLEDGMENTS
We would like to recognize the invaluable contributions of publication coordinators Karen Martin, Steve Schuenke, Eileen Figueroa, and administrator, Barbara Petit. Their dedicated professionalism, tenacious efforts, and cheerful cooperation are without parallel.
They accomplished whatever was necessary, often on short or instantaneous deadlines, and were vital for the successful completion of the endeavor.
Our authors, all respected authorities in their fields and busy physicians and surgeons, did an outstanding job in sharing their wealth of knowledge.
We would also like to acknowledge the professionalism of our colleagues at Elsevier: Developmental Editor, Kristina Oberle; Publication Service Manager, Julie Eddy; Project Manager, Laura Loveall; Designer, Louis Forgione; and Publishing Director, Judith Fletcher.
xi
C H A P T E R 1
THYROIDECTOMY (LOBECTOMY, SUBTOTAL RESECTION, TOTAL THYROIDECTOMY)
B. Mark Evers
STEP 1: SURGICAL ANATOMY
A comprehensive understanding of the anatomy of the neck is critical before undertaking surgical procedures on the thyroid.
Figure 1-1 demonstrates key anatomic structures that must be considered with thyroidectomy.
Figure 1-2 demonstrates the relationship of the thyroid gland with the underlying trachea and esophagus and also demonstrates the usual anatomic location for the recurrent laryngeal nerve in the tracheoesophageal groove.
STEP 2: PREOPERATIVE CONSIDERATIONS
The indications for thyroid resection include the following:
A solitary thyroid nodule usually with fine needle aspiration (FNA) indicative of a suspicious lesion or cancer;
A multinodular goiter with continued enlargement and symptoms ranging from dysphagia, choking, pain, or cosmetic concerns;
Occasionally hyperthyroidism particularly if radioiodine ablation or antithyroid medications are contraindicated.
Thyroid resections range from lobectomy and isthmusectomy, subtotal thyroid resection, or total thyroidectomy.
Decisions regarding the extent of resection are operator dependent and can be controversial.
2
C H A P T E R 1 • Thyroidectomy (Lobectomy, Subtotal Resection, Total Thyroidectomy) |
3 |
Hyoid bone 
Thyrohyoid muscle 
Thyroid cartilage
Cricothyroid muscle
Sternohyoid muscle
Middle thyroid vein
Sternothyroid muscle
Trachea 
Inferior thyroid vein
Left recurrent laryngeal nerve
Thyroid membrane
Superior thyroid artery and vein
Common carotid artery
Vagus nerve (X)
Internal jugular vein
Enlarged thyroid gland
Inferior thyroid artery
Vagus nerve (X) 
External juglar vein
Left recurrent laryngeal nerve
FIGURE 1–1
Fascia of infrahyoid muscle |
Pretracheal fascia |
|
|
Superficial (investing) fascia |
|
Platysma muscle |
Sternohyoid muscle |
|
Sternothyroid muscle |
||
Internal jugular vein |
||
|
||
Enlarged thyroid |
Omohyoid muscle |
|
|
||
Normal thyroid |
Sternocleidomastoid muscle |
|
|
||
|
Vagus nerve (X) |
|
|
Trachea |
Internal jugular vein
Carotid sheath
Internal carotid artery
Parathyroid gland
Esophagus
Recurrent laryngeal nerve
FIGURE 1–2
4 |
S E C T I O N I • H E A D A N D N E C K A N D E N D O C R I N E P R O C E D U R E S |
STEP 3: OPERATIVE STEPS
1.INCISION
Proper positioning of the patient is critical for adequate exposure of the thyroid gland. This is normally accomplished by hyperextension of the neck using a rolled sheet between the shoulder blades. The head is then supported with a foam rubber doughnut-shaped ring. In addition, the patient is placed in the semierect (semi-Fowler) position (Figure 1-3).
The incision must be carefully planned to allow optimal access to the thyroid gland, as well as to provide a cosmetically acceptable scar. The incision line is normally approximately two fingerbreadths above the sternal notch, placed to conform to Langer’s lines. The incision should be symmetrical and extend equidistant from the midline and have a gentle upward curve. Some surgeons use a heavy silk suture to outline the incision site by compressing the suture on the neck (Figure 1-4).
The incision extends through the subcutaneous tissue; the platysma muscle is divided using the electrocautery (Figure 1-5).
Flaps are then mobilized superiorly and inferiorly using the cautery, as well as blunt dissection, just deep to the platysma muscle. The superior flap is extended to the level of the thyroid cartilage and the inferior flap extends to the clavicular heads and suprasternal notch (Figure 1-6).
2.DISSECTION
A Mahorner retractor is used to retract the skin flaps. The dissection then proceeds in the midline raphe, which provides a bloodless plane for the separation of the strap muscles
(Figure 1-7).
Continuing in the midline, the loose pretracheal fascia is incised using sharp dissection or the electrocautery (Figure 1-8).
C H A P T E R 1 • Thyroidectomy (Lobectomy, Subtotal Resection, Total Thyroidectomy) |
5 |
Incision
FIGURE 1–3
FIGURE 1–4
FIGURE 1–5
FIGURE 1–6
Sternohyoid muscle
FIGURE 1–7 |
FIGURE 1–8 |
6 |
S E C T I O N I • H E A D A N D N E C K A N D E N D O C R I N E P R O C E D U R E S |
The thyroid lobe is further exposed by mobilizing the strap muscles away from the lobe using a combination of sharp and blunt dissection (Figure 1-9).
A small Richardson retractor is then placed under the strap muscles, retracting them laterally (Figure 1-10).
Occasionally, for large bulky thyroid lesions, better exposure of the thyroid lobe can be obtained by dividing the strap muscles, which are then approximated at the end of the procedure. If transection of the strap muscles is necessary, this should be performed superiorly to minimize denervation, because both of these muscle groups are innervated from a caudal direction through the ansa hypoglossi nerves (Figure 1-11).
The thyroid lobe is grasped with Babcock forceps (shown) and retracted gently toward the midline to expose the middle thyroid vein, which is ligated using either 3-0 or 4-0 silk suture and divided. This allows further mobilization of the lobe and identification of the parathyroid glands, as well as the recurrent laryngeal nerve (Figure 1-12).
C H A P T E R 1 • Thyroidectomy (Lobectomy, Subtotal Resection, Total Thyroidectomy) |
7 |
Anterior jugular vein
Sternohyoid muscle
Sternocleidomastoid
muscle
Superior thyroid artery and vein
FIGURE 1–9
Inferior thyroid vein
FIGURE 1–10
Sternohyoid
muscle
FIGURE 1–11
Middle thyroid vein
FIGURE 1–12
8 |
S E C T I O N I • H E A D A N D N E C K A N D E N D O C R I N E P R O C E D U R E S |
The thyroid gland is regrasped with the Babcock clamp and retracted downward to expose the superior pole vessels, including the branches of the superior thyroid artery. The external branch of the superior laryngeal nerve courses along the cricothyroid
muscle just medial to the superior pole vessels. Therefore, to avoid injuring this
nerve, which controls tension of the vocal cords, the superior pole vessels are divided individually as close as possible to the thyroid gland (Figure 1-13).
Next, the Babcock clamp is repositioned to grasp the thyroid lobe so that the inferior thyroid veins can be exposed and ligated as they enter the thyroid gland. Occasionally, a venous plexus (i.e., thyroid ima) is noted in the midline position over the trachea and entering the isthmus. These vessels are likewise carefully ligated and divided, avoiding injury to the trachea (Figure 1-14).