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Figure 5-10. Bisected ex vivo parathyroid adenoma.

Figure 5-9. Parathyroid adenoma excised through a 2 cm lateral

Figure 5-10. Bisected ex vivo parathyroid adenoma.

Parathyroid carcinoma and parathyroidosis are also more frequent in patients with familial PHPT with and without other endocrinopathies.52 The approach to patients with familial PHPT differs from that in patients with sporadic disease because the former are more likely to have inadequate removal of hyperfunc-tioning tissue (persistent disease) or redevelopment of hyperfunctioning tissue after 6 months (recurrent dis-ease).49-51 When a solitary parathyroid tumor is found, occurring in only 20% of cases, the normal-appearing parathyroid glands ipsilateral to the tumor are also removed, and any remaining normal-appearing parathyroid glands are biopsied and marked with a stitch or a clip. This is recommended in case the patient develops recurrent hyperparathyroidism as only one side of the neck would usually require reexploration. The thymus should be removed bilaterally as it is a common location for ectopic parathyroid glands; in patients with MEN type I disease, it can be the site of malignant carcinoid tumors.53,54

Some surgeons recommend total parathyroidec-tomy with immediate autotransplantation in patients with familial hyperparathyroidism as disease in patients with MEN type I and familial PHT without other endocrinopathies is highly likely to recur. Cry-opreservation should be performed in these situations for insurance against possible permanent hypoparathyroidism. Unfortunately, cryopreservation is effective only in approximately 60% of patients.55 Immediately autotransplanted parathyroid tissue appears to function in about 95% of patients. If a total parathyroidectomy is performed, the surgeon should look out for early and late hypoparathyroidism, which

Figure 5-11. Example of intraoperative parathyroid assay measurements (pg/mL) obtained pre- and postexcision of adenoma. A 50% decline in the absolute values suggests cure. Reproduced with permission from Boggs JE et al.38

Prr excisión Post excision

Prr excisión Post excision

Figure 5-11. Example of intraoperative parathyroid assay measurements (pg/mL) obtained pre- and postexcision of adenoma. A 50% decline in the absolute values suggests cure. Reproduced with permission from Boggs JE et al.38

has been reported after parathyroid autotransplanta-tion.56 Autotransplantation is performed by mincing parathyroid tissue into 1 mm slices (Figure 5-12) and reimplanting into 15 to 20 individual pockets of the forearm via one skin incision. The forearm is used as it is easier to document whether the transplant is functional by documenting a twofold increase in the basilic vein PTH level compared with the contralateral side.

Patients with persistent or recurrent disease despite subtotal parathyroidectomy should usually undergo either subtotal resection of the remaining abnormal parathyroid gland or it should be removed, autotransplanted, and cryopreserved. If there is any question about the viability of the parathyroid remnant that is to remain, it should be removed and autotransplanted or another hyperplastic gland, when present, should be biopsied and marked before removing the other hyper-plastic glands. Again, tissue should be cryopreserved.

Patients with MEN type IIA should be selectively managed as they require total thyroidectomy with removal of central neck lymph nodes. This makes them more prone to hypoparathyroidism. These patients should have only the abnormal parathyroid glands removed to avoid this risk, although some surgeons recommend total parathyroid autotransplantation. This is also discussed further in other chapters.

Ethanol ablation is a new procedure under development at the Mayo Clinic. Candidates are patients who have undergone a subtotal parathyroidectomy for multigland disease with subsequent recurrence owing to the remnant. Hypoparathyroidism and RLN damage are rarely seen with this procedure. However, cure rates are much lower than with surgery, and alcohol injection can complicate future surgical attempts. Thus, using this modality should be a joint decision between the endocrine surgeon, endocrinologist, and radiologist.9

Because the majority of cases of PHPT are caused by a single parathyroid adenoma, there is much evolving interest and excitement about using minimally invasive parathyroidectomy (MIP), which is depicted in Figure 5-13. Minimally invasive approaches include (1) unilateral open approaches, (2) the open minimally invasive procedure, and (3) endoscopic parathyroidectomy. The first method uses the conventional Kocher cervical incision followed by unilateral neck exploration (UNE). The second involves small, selective incisions under local or regional anesthesia.37 This procedure is not performed with MEN, isolated familial HPT, or secondary HPT as bilateral exploration is necessary, as discussed in Chapter 6. It involves the use of ses-tamibi scans for preoperative localization, surgeon-administered cervical block anesthesia, directed exploration, and rapid IOPTH assay.

Limited parathyroid surgery is safe, cost effective, and efficacious in the management of PHPT.

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