Background: Hypocalcemia is one of the most frequent complications after thyroid surgery. The aim of this study was to investigate the clinical relevance, outcome, follow-up and management of patients with incidental parathyroidectomy during thyroid surgery.
Subjects and methods: Two hundred and thirty-one patients (5.2%, 200 females and 31 males) of 4206 operated patients, which presented between 1989 and 2007 in our out-patient endocrine department, suffered from hypoparathyroidism and were retrospectively evaluated. Fifty-eight percent of these patients had undergone total thyroidectomy, 42% partial thyroidectomy. Preoperative diagnoses were: goiter with or without thyroid nodules 64%, Graves’ disease 12%, thyroid cancer 20%.
PTH and serum calcium were assessed on the first visit and further on.
Results: Patients presented after a mean of 84±132 months after thyroid surgery. Clinical symptoms at the first visit were: paresthesia in 36% and cramps/tetany in 24%/13%.
A total of 57% recieved no treatment – neither calcium nor vitamin D – at the first visit, 22% of patients received 1,25-hydroxyvitamine D3, 13% dihydrotachysterol, 8% vitamin D3 and 1% 1-alpha-hydroxyvitamie D3. PTH levels at the first visit under the different treatment regimens were 14.24±6 pg/ml, calcium levels 2.16±0.6 mmol/l.: At a second visit 4–12 months later symptoms had decreased to: paresthesia in 24% (at visit 4 (V4) after another year or more: 6%), cramps/tetany in 5%/2% (V4: 3/0%). Most patients received treatment with 1,25-hydroxyvitamine D3: 27% at visit 2 and 18% at V4. Calcium levels at visit 2 were: 2.18±0.51 and 2.17±0.21 mmol/l at visit 4.
Conclusions: Permanent hypoparathyroidism following incidental parathyroidectomy during thyroid surgery is a common but often disregarded complication – mainly in female patients. Patients after thyroid surgery should be regularily screened for clinical symptoms and low PTH- or calcium-levels. Treatment with 1,25-hydroxyvitamine D3 seems to be an appropriate therapy to maintain (near-) normal calcium levels and preserve patients from symptoms of hypocalcemia.