Thyroid Surgery - Intra Op Flashcards
Thyroid Surgery - Steps
- Elevate the Platysma
- Retract the strap laterally in the mid line
- Identify and ligate the middle thyroid vein
- Identify and protect the inferior parathyroid gland
- Gland is almost always anterior/ventral to the RLN
- Reflect the inferior parathyroid laterally
- Identify and protect the RLN
- Identify and protect the Superior parathyroid gland
- Gland is almost always at the level of the cricoid cartilage adjacent to the recurrent laryngeal nerve entry point
- Dissect the superior pole
- Identify the trachea above and below the thyroid isthmus - establishes a constant visible mid line
- Assess hemostasis of the surgical bed prior to closure. Check the strap mscls, airway, and platysma/skin flap
Parathyroid Gland Identification
- > 90% of Superior Parathyroid glands are located at the level of the cricoid cartilage
- The superior parathyroid gland is deep/dorsal to the RLN and the inferior parathyroid is superficial/ventral to the RLN
- Identify the superior parathyroid gland first
- Color: brown to reddish tan, salmon color
- Parathyroid glands have a vascular pedicle or vascular strip
- The parathyroid surface is smooth
- Parathyroid gland is usually kidney bean shaped (but can have other shapes)
- Usually distinct/separate from the surface of the thyroid gland
- Glide sign - like rowboat on a wave
- Parathyroid Glands have side to side symmetry
- Every parathyroid should be considered the last parathyroid
Superior Parathyroid Identification
- Usually located in fat lobules closely associated with the posterolateral surface of the thyroid lobe deep to the plane of the RLN. Serially reflect all the thin layers of fascia overlying the true thyroid capsule on the deep side of the superior thyroid lobe. Stay immediately on the superior pole capsule.
- > 90% found withing 1 cm of the cricothyroid articulation
- Less constant landmark: 1 cm cranial to the intersection of the inferior thyroid artery and the RLN
Inferior Parathyroid Identification
- Located within 1 cm inferior or lateral to the inferior thyroid pole
- Superficial to the RLN
- Often seen with gentle manipulation of the thyrothymic fat directly underneath the strap mscls, extending from the anterior mediastinum to the inferior surface of the inferior thyroid pole
Contralateral Thyroid Lobe Removal: Safety Checklist
- Make sure that there is a good reason to remove the contralateral lobe:
- Is there a malignancy that warrants contralateral surgery?
- Is there benign nodularity that requires contralateral surgery?
- Make sure that the ipsilateral RLN is intact visually and electrically
- Are the ipsilateral parathyroid glands intact and viable?
What are the key steps in reoperative therapy for recurrent benign thyroid disease/goiter?
1) Identification of anatomic landmarks outside of the original operative field in order to facilitate orientation and subsequent dissection
2) Identification of the recurrent laryngeal nerve in virgin territory if possible
3) Identification of all remaining parathyroid glands with appropriate measures to ensure their ongoing function
What are the three principal approaches to finding the recurrent laryngeal nerve in undissected territory in reoperative thyroid surgery for benign disease?
1) The lateral or backdoor approach (the preferred approach)
2) The inferior approach
3) The superior approach
What is the ‘Backdoor approach’ to the recurrent laryngeal nerve in reoperative thyroid surgery for benign disease?
This approach involves dissecting down the medial border of the SCM muscle, then across the common carotid artery to the prevertebral fascia. Dissection continues medially toward the esophagus and tracheoesophageal groove. Careful progressive dissection, assisted by frequent palpation in the reoperative area will often reveal the recurrent laryngeal nerve before it enters the scarred reoperative site.
What is the ‘Inferior approach’ to the recurrent laryngeal nerve in reoperative thyroid surgery for benign disease?
The tracheoesophageal groove is approached anteriorly, dissecting across and lateral to the thymus as low as possible. The recurrent laryngeal nerve is identified as it emerges from the upper mediastinum having ‘recurred’ around the aortic arch on the left side or the subclavian artery on the right. It would be unusual for this area to have been disturbed during prior surgery, and the recurrent laryngeal nerve can usually be readily identified and dissected superiorly through the scar tissue.