Endocrine Flashcards
Thyroidectomy
- intubate with nerve monitor, gently extend neck
- Transverse cervical incision 1 cm inferior to cricoid cartilage, create subplatsymal flaps, separate straps and dissect them off the thyroid
- Ligate middle thyroid vein
- Take superior pole vessels as close to thyroid as possible
- Mobilize thyroid anteriorly & medially to Identify RLN in the TE groove, trace to insertion in cricothyroid membrane, keep dissection as close to thyroid as possible
- Take inferior pole vessels
- Identify and preserve parathyroids by performining capsular dissection
- Divide ligament of berry and remove thyroid from the airway
Parathyroidectomy
Know where to find missing superior & inferior adenomas
Know what to do if all parathyroids are normal ie 4 gland exploration
- Draw baseline PTH, place patient supine, arms tucked, neck slightly extended, intubated with RLN monitoring capabilities
- Transverse cervical incision 1cm inferior to cricoid cartilage
- Raise subplatsymal flaps, separate strap muscles and dissect them off the thyroid
- Ligate middle thyroid vein
- Retract the thyroid gland medially, look for parathyroid glands close to inferior thyroid artery and RLN:
- superior is deep/posteriolateral to plane of nerve,
- inferior is superficial/anteriomedial to plane of nerve - Excise the adenoma, check PTH at 5 min and 10 min to ensure 50% drop from baseline & normal levels (<55 pg/mL)
→ Missing superior adenoma is likely in retroesophageal space or carotid sheath @ bifurcation
→ Missing inferior adenoma → Thymus vs intra-lobar
For four gland exploration, identify each gland.
→ If all normal, clip & send for frozen prior to excision. Excise 3.5 glands.
→ If still doesnt drop, perform b/l thymectomy as likely extranumary gland is in thymus… then close and get more imaging if still no improvement
LEFT adrenalectomy
- Left side up, ports along costal margin, assess for mets, open w subcostal incision
- Mobilize splenic flexure, spleen, & tail of pancreas (if unable to, then enter lesser sac)
- Dissect retroperitoneal structures including Gerota’s fascia, left renal hilum, para-aortic space
- Identify, ligate, divide L adrenal vein
- Dissect L suprarenal tissues with enbloc resection of retroperitoneal fat from superior pole of L kidney to the diaphragm
RIGHT adrenalectomy
- Right side up, ports along costal margin, assess for mets, open w subcostal incision
- Mobilize triangular ligament of liver and perform medial rotation of right liver lobe to expose IVC
- Dissect R border of IVC
- Identify, dissect, clip R adrenal vein
- Dissect R suprarenal tissues with enbloc resection of retroperitoneal fat from superior pole of R kidney to the diaphragm
Bethesda system for Thyroid cytopathology & malignancy
I - nondiagnostic
II - benign
III - AUS/FLUS
IV - FN/SFN
V - suspicious for malignancy
VI - malignant
Indications for total thyroidectomy
- Extra-thyroidal disease (extends beyond capsule, clinically + nodes, mets)
- Tumor ≥4 cm
- Multicentric/bilateral
- History of XRT
Indications for MRND (LN’s I-V)
Extra-thyroidal disease (extends beyond capsule, clinically + nodes, mets)
Indications for post-op radioactive iodine at 4-6 weeks post-op (need TOTAL thyroidectomy to work, should NOT be administered to children or preggers)
- Extra-thyroidal disease (extends beyond capsule, clinically + nodes, mets)???
- Tumor ≥4 cm
- Post-op thyroglobulin > 5-10 ng/mL
- Bulky or > 5 positive lymph nodes
- Can also be used for recurrent cancer
Follow up after lobectomy/total thyroidectomy for low risk tumors & high risk/advanced tumors
LOW RISK
After lobectomy → Check TSH 6 weeks after surgery, U/S 6 months then annually
HIGH RISK
After thyroidectomy & RAI ablation →
Diagnostic whole body radioactive iodine (RAI) scan evaluate for persistent/recurrent disease
**If scan is negative with rising thyroglobulin (> 10 ng/mL), 18fluorodeoxyglucose–positron emission tomography (18FDG-PET) should be considered.
Thyroid work up - dont forget to ask & dont forget to order
Hx compressive symptoms, hyperthyroidism symptoms (anxiety, palpitations, weight loss, etc), hypothyroidism symptoms, family/personal endocrine & malignant CA
Hx radiation, Hx neck surgery
EYE symptoms! periorbital swelling, eye dryness, photophobia, etc
TSH normal or high → U/S & FNA
TSH low → TRAb & Thyroid scintigraphy
Hyperparathyroidism work up - dont forget to ask & dont forget to order
Confirm no alternative causes for hypercalcemia (ie meds)
Personal/family hx of malignancy/endocrine disorders
Kidney stones, osteoporosis/compression fracture
Vitamin D,
PTH,
phosphate,
chloride
24h urinary calcium excretion
If asymptomatic, order bone scan & b/l renal U/S
Indications for surgery in hyperparathyroidism
Symptomatic disease
Asymptomatic disease with
1. Ca > 1.0mg/dL above normal (10.3)
2. ↓ Cr clearance
3. Kidney stones
4. Substantially ↓ bone mass (densitometry T score < −2.5) or osteoporosis/compression fracture
5. Age < 50
6. Urinary calcium excretion > 400 microgram/24 hours
7. History of life-threatening hypercalcemic crisis
Parathyroid adenoma localization
U/S first, then 4D CT scan vs sestamibi scan
Adrenal mass H&P don’t forget to ask
- Personal/family history of malignancy & endocrine disorders
Symptoms of hormonal excess
2. Hypercortisolism → weight gain, bruising, HTN, hyperglycemia, muscle weakness
3. Hyperaldosteronism → HTN, hypokalemia
4. Pheochromocytoma → Tachycardia, headache, HTN, anxiety
Screening for adrenal functional tumors (do this for ALL adrenal masses)
- 1 mg LD dexamethasone suppression test: Patients take 1 mg Dexamethasone at 10PM, then have Cortisol levels drawn the next morning;
→ Normal/Negative Cortisol < 1.8
→ Hypercortisolism > 5
→ 1.8 - 5 → need 24h urinary free cortisol levels to confirm - Serum ACTH
- Serum Aldosterone & Renin
- DHEA-Sulfate (CA marker)
- Plasma free metanephrines; If elevated, need 24h urinary metanephrines testing to confirm
Central neck dissection
Identify & protect b/l RLN
Remove all fibroadipose tissue between carotid sheaths, hyoid bone, brachiocephalic vessels
Lateral neck dissection
Remove all fibroadipose tissue from lateral neck (all LN I-V , not central VI), borders defined by submandibular gland superiorly, IJV medially, trapezius laterally, clavicle inferiorly
