Subtotal Thyroidectomy (Removal of Thyroid)

Incision for Subtotal Thyroidectomy

In subtotal thyroidectomy, the patient is placed supine (face up) on the operating room table. A folded towel is placed under the neck to hyperextend the neck. The top part of the table is elevated so the patient is in a slightly reclining position. The head must be perfectly aligned with the body so a symmetrical incision is made by the surgeon. The incision is made transversely (side to side) about two fingers breadth above the sternal notch. It should be placed in a skin crease if possible for best cosmetic result. Most commonly, a slight indentation is made in the skin by using a heavy silk suture to compress the skin.

The incision for subtotal thyroidectomy should extend well beyond the borders of the sternocleidomastoid muscles (there is one on each side of the neck). For large goiters, the incision is made a little more cephalad (toward the head). By usual convention the surgeon stands on the right as the right side of the thyroid is removed first. The incision is made using one sweep of the belly of the blade across the skin and through the subcutaneous tissue.

subtotal thyroidectomy anatomy for sternocleidomastoid

Surgical Details of the Subtotal Thyroidectomy Procedure

1. Bleeding vessels in the skin and subcutaneous tissue are controlled by applying hemostats and ligated using 3-0 or 4-0 absorbable sutures.

2. Incision is carried through the rather superficial platysma muscle to the avascular (without blood vessels) plane below this muscle.

3. Care must be taken to avoid severing the anterior jugular veins

4. Tissue flaps in subtotal thyroidectomy are raised both superiorly and inferiorly using a combination of blunt and Bovie cautery dissection.

5. The superior dissection (toward the head) is taken up to the level of the thyroid cartilage and the inferior dissection (toward the feet) is taken to the level of the sternal notch.

6. The large vein usually found under both flaps is ligated (tied off) with silk suture and incised (cut) with a Metzenbaum scissors.

7. At the lower flap margin care must be taken to avoid the communicating arch between the right and left anterior jugular veins to avoid the possibility of air embolus. The left and right anterior jugular veins are usually ligated (tied off) with double silk ties and incised (cut) with a scissors.

8. A self-retaining retractor is then placed to hold the two edges of the skin flaps apart to allow adequate exposure of the underlying strap muscles.

9. The sternohyoid muscle is lifted up on either side of the midlline and an incision is made in the exact midline of the sternohyoid muscle. Alternately, the sternohyoid muscle can be incised transversely with Bovie cautery and retracted inferiorly and superiorly.

10. Blunt dissection is used to develop the plane underneath the sternohyoid muscle. This will expose the sternothyroid muscle.

11. The sternothyroid muscle is incised after the loose areolar tissue is grasped and retracted toward the ceiling. It is important when performing a subtotal thyroidectomy to enter the correct plane between this muscle and the thyroid.

12. This exposes the capsule of the thyroid and the anterior capsular veins of the thyroid.

13. The thyroid gland is then partially delivered up into the wound by placing two fingers and the lateral edge of the gland and slightly separating them. Care must be taken to avoid injuring the middle thyroid gland.

14. Many surgeons ligate and divide the right middle thyroid vein at this time.

15. The dissection of the thyroid gland is usually done by freeing the right upper pole first.

16. Dissection is done either by gentle blunt force by inserting a finger or hemostat under the right superior thyroid vessels.

17. The vessels are ligated with silk ties or very commonly with a Harmonic scalpel.

18. It is important in subtotal thyroidectomy that all vessels be carefully ligated as it is difficult to control cut vessels that have not been ligated as they tend to retract to a position very near the superior laryngeal nerve.

19. The superior thyroid artery should be ligated outside of and away from the gland.

20. After the right superior thyroid vessels and the right middle thyroid vein have been controlled, attention is turned to the right lower pole of the thyroid.

21. The inferior pole arteries and veins are carefully ligated with care taken not to disrupt the adjacent parathyroid gland or to injure the underlying trachea.

22. If a thyroidea ima (venous plexus or group of veins) is present, it is carefully separated from the trachea and ligated and divided,

23. The inferior thyroid artery is then located on the inferior lateral part of the gland by retracting the thryoid medially and superiorly.

24. This artery is ligated. Great care must be taken to completely separate it from the right recurrent laryngeal nerve that is always found adjacent to the artery (it may even run between the bifurcation (branches) of the artery).

25. It must be remembered in resecting large thyroid glands in subtotal thyroidectomy that the right recurrent laryngeal nerve may be more superficial than expected.

26. The right side of the gland is then dissected off of the trachea using find tipped forceps to guide the Bovie cautery and a small sponge to push the thryoid medially.

27. When the midline of the trachea has been reached (the isthmus), clamps are placed on each side to compress the thyroid tissue.

28. The isthmus is then divided between the two rows of clamps using Bovie cautery. The right thyroid specimen is then removed from the operating theater.

29. The surgeon moves to the patient’s left side and removes the left side of the thyroid gland using the same steps as described above.

30. After the gland has been removed in subtotal thyroidectomy, the folded sheet behind the patient’s neck is removed and the hyperextension of the neck is released.

31. The wound is irrigated and the field is repeatedly check for any bleeding points. Meticuluos hemostasis is critical in thyroid surgery to prevent a clot from forming and compressing the trachea.

32. Many surgeons will leave a small suction-type drain in the thyroid cavity, even in the presence of a dry field. This is brought out through a stab wound the skin laterally on the neck.

33. The strap muscles (prethyroid muscles) are then reapproximated and if transected are closed using 2-0 or 3-0 absorbable interrupted suture.

34. The platysma muscle is reapproximated using a 4-0 or 3-0 interrupted absorbable suture.

35. The subcutaneous tissue is reapproximated using a 4-0 interrupted absorbable suture.

36. The skin is closed after performing a subtotal thyroidectomy by using a subcuticular (just below the skin surface) aborbable stitch (e.g., Monocryl) or interrupted 4-0 or 5-0 nylon sutures

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