Endocrine: Parathyroidectomy

Minimally Invasive (Focused) Parathyroidectomy

Positioning

Procedure

Expose the Thyroid:
- Transverse “Kocher Incision”
  - 1-2 Fingerbreadths Above Sternal Notch
  - Traditional Incision: 8-10 cm Long – Generally Shorter (5-6 cm) in Modern Practice
  - Minimally Invasive Incision: 2-4 cm Long
- Divide Platysma
  - Superior Subplatysmal Flap Carried to Cricoid Cartilage
  - Inferior Subplatysmal Flap Carried to Sternal Notch
- Divide Midline Raphe (Avascular Plane Between Strap Muscles)
- Dissect the Anterior Capsule of the Ipsilateral Thyroid Lobe from Medial to Lateral
Identify & Resect the Parathyroid Gland:
- Roll/Rotate the Ipsilateral Thyroid Medially
- Caution:
  - Ensure Meticulous Intraoperative Hemostasis
  - Avoid Thyroid Capsule Rupture
  - Avoid Damage to Recurrent Laryngeal Nerve
  - Avoid Damage to Normal Parathyroid Glands
- Identify & Resect the Diseased Parathyroid Gland
  - Avoid Capsule Rupture – Causes Parathyromatosis (Diffuse Cervical Implantation)
  - Avoid Injury to RLN & Inferior Thyroid Artery
- Verify Diseased Gland was Resected (Frozen Section vs Blood-Intact PTH)
  - *See Below
Finish & Close
- Obtain Hemostasis
- Close Strap Defect
- Close Platysma Defect
- Close Skin

“Miami Criteria” (Intraoperative PTH)

Criteria: PTH Drop ≥ 50%
Draws:
- Initial: Preoperative or Preexcision
- Comparison: 10- or 20-Minutes Post-Resection
97-99% Cure Rates
If Fails to Drop 50%: Bilateral Exploration (Reasonable to Explore Ipsilateral First)
- If Drawn at 10-Minutes Do Not Need to Wait Until 20-Minutes

Confirmation of Gland Resection

Frozen Section
- Confirm Parathyroid Tissue
Ex-Vivo Aspiration of Gland
- Aspirate Intraoperative PTH > 1.5x Baseline Level

Parathyreoidectomy ¹

Positioning

Procedure

Expose the Thyroid:
- Transverse “Kocher Incision”
  - 1-2 Fingerbreadths Above Sternal Notch
  - Traditionally 8-10 cm Long – Generally Shorter (5-6 cm) in Modern Practice
- Divide Platysma
  - Superior Subplatysmal Flap Carried to Cricoid Cartilage
  - Inferior Subplatysmal Flap Carried to Sternal Notch
- Divide Midline Raphe (Avascular Plane Between Strap Muscles)
Expose Parathyroid Glands on One Side:
- Dissect the Anterior Capsule of One Lobe of the Thyroid from Medial to Lateral
- Roll/Rotate the Ipsilateral Thyroid Medially
- Identify the Ipsilateral Superior & Inferior Parathyroid Glands
- Caution:
  - Ensure Meticulous Intraoperative Hemostasis
  - Avoid Parathyroid Capsule Rupture – Causes Parathyromatosis (Diffuse Cervical Implantation)
  - Avoid Thyroid Capsule Rupture
  - Avoid Damage to Recurrent Laryngeal Nerve
Expose Parathyroid Glands on the Contralateral Side
Visually Inspect All Four Glands:
- 1-3 Glands Enlarged: Resect All Enlarged Glands
- 4 Glands Enlarged: Subtotal vs. Total Parathyroidectomy
Finish & Close
- Obtain Hemostasis
- Close Strap Defect
- Close Platysma Defect
- Close Skin

Subtotal (3.5 Gland) Parathyroidectomy

Resect 3.5 Glands, Leaving a Half Gland Behind
First Resect the Half Gland, Then Resect the 3 Complete Glands
- Resect the Lateral Half of the Gland (Artery Enters Medially)
Leave Equivalent Volume of a Normal Parathyroid Gland

Total Parathyroidectomy with Autoimplantation

Resect All 4 Glands
Harvest:
- Harvest an Equivalent Volume of a Normal Parathyroid Gland
- Use the Most Normal Appearing Gland
- Sharply Mince Tissue into a Fine Slurry
Reimplantation:
- Expose Nondominant Brachioradilais Muscle in the Forearm
  - Some Prefer to Use the Sternocleidomastoid Muscle in the Neck
- Make 3-4 Pockets in the Muscle Belly
- Place Equal Volumes of Slurry into Each Pocket
- Close Pockets with Nonabsorbable Suture

Missing Gland

Intraoperatively Unable to Find: Search
- Order of Search:
  - Cervical Thymectomy (#1)
  - Open Carotid Sheath (#2)
  - Intraoperative Thyroid US
- May Consider Ipsilateral Thyroid Lobectomy if Needed
- Close if Still Unable to Find
Postoperatively Still Unable to Find: Follow PTH
- Repeat Sestamibi Scan in 3-6 Months if PTH Still High

Hypocalcemia

Causes:
- Transient Hypoparathyroidism
  - Common After Parathyroidectomy from Suppressed Function
  - Generally Regains Function After a Few Days
- Aparathyroidism
  - Cause: Remnant/Graft Failure
  - Labs: Decreased PTH, Normal Bicarb
- Hungry Bone Syndrome (HBS)
  - Cause: High Calcium Absorption in Bone
    - From Severe Pre-Operative Bone Disease
  - Labs: Normal PTH, Decreased Bicarb
Management: Monitor Ca/PTH Every 1-2 Weeks
- All Patient Should Empirically Be Given Oral Calcium Supplementation
  - May Consider Oral Vitamin D Supplementation as Well
- Can Supplement Increased PO/IV Calcium as Needed

Hyperparathyroidism

Cervical Hematoma

Risk: 0.3-1.0%
Must Ensure Meticulous Intraoperative Hemostasis
Even Low-Volume Bleeding Can Cause Life-Threatening Airway Obstruction
Can Cause Airway Edema from Venous/Lymphatic Obstruction Making Intubation Difficult
Treatment:
- Respiratory Distress: Emergently Open at Bedside
- Not in Respiratory Distress: Intubate & Emergently Open in the OR

Recurrent Laryngeal Nerve Injury