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Parathyroidectomy

From Wikipedia, the free encyclopedia
Parathyroidectomy
surgical photo of parathyroid gland removal
Parathyroidectomy for parathyroid adenoma
SpecialtyGeneral surgery, endocrine surgery
ComplicationsHypo­para­thyroidism
ApproachOpen
Other optionsCalcimimetics

Parathyroidectomy is the surgical removal of one or more of the (usually) four parathyroid glands. This procedure is used to remove an adenoma or hyperplasia of these glands when they are producing excessive parathyroid hormone (PTH), a condition termed hyper­para­thyroidism. The glands are usually four in number and located adjacent to the posterior surface of the thyroid gland, but their exact location is variable. When an elevated PTH level is found, a sestamibi scan or an ultrasound may be performed in order to confirm the presence and location of abnormal parathyroid tissue.

Indications

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The main indication for parathyroidectomy is primary hyper­para­thyroidism, a condition in which one or more of the parathyroid glands produce excessive parathyroid hormone. Not all cases of primary hyper­para­thyroidism require surgery, but it is recommended if the condition causes significant symptoms or if it affects the kidneys (nephro­calcin­osis) or bone health (osteo­por­osis), and also in people under 50 even if they do not have symptoms.‍[1] It is not always possible to anticipate if a parathyroid tumor is malignant (i.e. capable of invading other tissues or spreading elsewhere). Any suspicion of parathyroid carcinoma is therefore also an indication for surgery.‍[1]

Parathyroidectomy may also be required in secondary hyper­para­thyroidism. This situation arises mainly in people with severe chronic kidney disease (CKD) in which the parathyroid glands are overactive to compensate for the low calcium (hypo­calcemia) and vitamin D (vitamin D deficiency) levels often present in CKD. In many cases, the parathyroid hormone production improves when these abnormalities are treated with medication. A small proportion, however, have persistently raised hormone levels six months after treatment has started, thought to be autonomous production of hormone by the glands and loss of feedback mechanisms. In this situation surgical para­thyroid­ectomy may be required, especially if calcium and phosphate levels remain elevated (respectively, hyper­calcemia and hyper­phospha­temia), there is calcium deposition in the wall of blood vessels (calciphylaxis in severe cases) or there is worsening bone disease. In people on kidney dialysis, para­thyroid­ectomy can improve survival. It does appear that the procedure may be underused.‍[2]

Procedure

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The operation requires general anesthesia (unconscious and pain-free) or local anesthesia (pain-free). The surgeon makes an incision around 2+12 centimetres (1 inch) long in the neck just under the larynx ("Adam's apple"), and locates the offending parathyroid glands. Pre­operative testing using sestamibi scanning can help identify the location of glands. It can also be used to limit the extent of surgical exploration when used in conjunction with intra­operative parathyroid hormone (PTH) monitoring.‍[3] The particular problem or disease process will determine how many of the parathyroid glands are removed. Some parathyroid tissue must be left in place to help prevent hypo­para­thyroidism.

Recovery after the operation tends to be swift. The PTH level is back to normal within 10 to 15 minutes, and can be confirmed by intraoperative rapid assessment during the operation. However, the remaining parathyroid glands may take hours to several weeks to return to their normal functioning levels (as they may have become dormant). Calcium supplements are therefore often required to prevent symptoms of hypocalcemia and to restore lost bone mass.‍[4]

The patient is placed in a semi-Fowler position and the neck is extended. An abbreviated Kocher incision is made and the platysma muscle is dissected horizontally. The strap muscles are released off of the thyroid gland. Then the thyroid gland is mobilized and the parathyroid arterial blood supply is suture ligated. The entire parathyroid adenoma is identified and dissected out. Intra­operative PTH monitoring can begin at this time and will show falling PTH levels if the entire adenoma has been resected.‍[5]

Complications

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While mild hypocalcemia is common after partial para­thyroid­ectomy, some people experience persistently prolonged low calcium levels. This is called hungry bone syndrome. In such a scenario, despite re­activation of unresected parathyroid glands producing normal-to-elevated levels of parathyroid hormone, serum calcium continues to be low. The balance between calcium influx and efflux within the bone continues to be disrupted, favoring the former. The bone is said to be "hungry" as it consumes minerals without regard to parathyroid hormone levels; calcium, magnesium, and phosphate continue to be deposited into the bones, resulting in ongoing hypo­calcemia, hypo­magnesemia, and hypo­phospha­temia. Prolonged calcium supplementation may be required. Hungry bone syndrome is particularly common in people who are on long-term kidney dialysis.‍[2][6]

See also

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References

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  1. ^ a b Wilhelm, Scott M.; Wang, Tracy S.; Ruan, Daniel T.; Lee, James A.; Asa, Sylvia L.; Duh, Quan-Yang; Doherty, Gerard M.; Herrera, Miguel F.; Pasieka, Janice L.; Perrier, Nancy D.; Silverberg, Shonni J.; Solórzano, Carmen C.; Sturgeon, Cord; Tublin, Mitchell E.; Udelsman, Robert; Carty, Sally E. (1 October 2016). "The American Association of Endocrine Surgeons Guidelines for Definitive Management of Primary Hyperparathyroidism". JAMA Surgery. 151 (10): 959–968. doi:10.1001/jamasurg.2016.2310. eISSN 2168-6262. ISSN 2168-6254. PMID 27532368. S2CID 4007319.
  2. ^ a b Lau, Wei Ling; Obi, Yoshitsugu; Kalantar-Zadeh, Kamyar (7 June 2018). "Parathyroidectomy in the Management of Secondary Hyperparathyroidism". Clinical Journal of the American Society of Nephrology. 13 (6): 952–961. doi:10.2215/CJN.10390917. eISSN 1555-905X. ISSN 1555-9041. LCCN 2005214803. OCLC 60194474. PMC 5989682. PMID 29523679.
  3. ^ Augustine, Mathew M.; Bravo, Paco E.; Zeiger, Martha A. (Mar–Apr 2011). "Surgical treatment of primary hyperparathyroidism". Endocrine Practice. 17 (Suppl 1): 75–82. doi:10.4158/EP10359.RA. eISSN 1934-2403. ISSN 1530-891X. OCLC 35074613. PMID 21324817. CODEN EPNRAT.
  4. ^ The American Association of Endocrine Surgeons (10 January 2024) [First published 24 October 2023]. "Parathyroid Surgery". The AAES Endocrine Disease Patient Education Website. Archived from the original on 15 June 2024.
  5. ^ Carling, Tobias (19 April 2022). "Minimally invasive parathyroidectomy under local cervical block anesthesia for primary hyperparathyroidism and parathyroid adenoma". J Med Insight. 2022 (225). doi:10.24296/jomi/225.
  6. ^ Jain, Nishank; Reilly, Robert F. (July 2017). "Hungry bone syndrome". Mineral Metabolism. Current Opinion in Nephrology and Hypertension. 26 (4). Lippincott Williams & Wilkins: 250–255. doi:10.1097/MNH.0000000000000327. eISSN 1473-6543. ISSN 1062-4821. PMID 28375869. S2CID 4630106.
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