| 1. |
- Bergenfelz, A, et al.
(author)
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Intraoperative fall in plasma levels of intact parathyroid hormone after removal of one enlarged parathyroid gland in hyperparathyroid patients
- 1991
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In: Acta Chirurgica Scandinavica. - 0001-5482. ; 157:2, s. 12-109
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Journal article (peer-reviewed)abstract
- Plasma levels of intact parathyroid hormone (PTH) were measured intraoperatively before and after removal of one enlarged gland in 20 hyperparathyroid patients. In 13 patients with a single parathyroid adenoma, plasma levels of intact PTH-(1-84) had declined at 15 min after removal of the adenoma by 86.5 +/- 4.4% of baseline in the antecubital vein and by 85.6 +/- 4.2% in the ipsilateral internal jugular vein. In seven patients with parathyroid hyperplasia, the corresponding figures for decline at 15 min after removal of one enlarged parathyroid gland were only 26.6 +/- 6.4% and 7.8 +/- 29.4%. The fall in PTH levels was significantly less in hyperplasia than in adenoma (p less than 0.001). Thus 15 min after removal of one enlarged parathyroid gland, the decline in plasma level of intact PTH may distinguish between single adenoma and multiglandular disease as the cause of hyperparathyroidism.
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| 2. |
- Bergenfelz, A, et al.
(author)
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Persistent elevated serum levels of intact parathyroid hormone after operation for sporadic parathyroid adenoma : evidence of detrimental effects of severe parathyroid disease
- 1996
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In: Surgery. - 0039-6060. ; 119:6, s. 33-624
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Journal article (peer-reviewed)abstract
- BACKGROUND: A significant number of patients with primary hyperparathyroidism (pHPT) who are surgically treated have increased serum levels of intact parathyroid hormone (PTH) during long-term follow-up despite normocalcemia. The cause and significance of this finding remain to be established.METHODS: A total of 82 patients operated on for sporadic parathyroid adenoma were investigated before and at 8 weeks and 1 year after operation with serum levels of intact PTH, bone mineral content, and biochemical variables known to reflect PTH activity.RESULTS: All patients had low or normal serum levels of calcium during follow-up. At 8 weeks after operation 20 (24%) patients had increased serum levels of PTH. These patients had severe parathyroid disease and low levels of 25(OH) vitamin D before operation. In contrast to patients with normal levels of PTH after operation, they did not have an elevated bone mineral content but had elevated levels of serum creatinin. At 1 year after operation 13 patients had elevated serum levels of PTH. Compared with patients with normal serum levels of PTH, they were older and had an increased frequency of cardiovascular disease and biochemical indications of compromised renal function. They did not have an elevated bone mineral content.CONCLUSIONS: Persistently increased serum levels of PTH indicate harmful effects of pHPT even after surgical cure, especially in elderly patients with severe disease before operation. The results in this investigation therefore favor early treatment of pHPT.
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| 3. |
- Bergenfelz, A, et al.
(author)
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Sestamibi versus thallium subtraction scintigraphy in parathyroid localization : a prospective comparative study in patients with predominantly mild primary hyperparathyroidism
- 1997
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In: Surgery. - 0039-6060. ; 121:6, s. 5-601
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Journal article (peer-reviewed)abstract
- BACKGROUND: Technetium 99m sestamibi was recently introduced for the preoperative localization of abnormal parathyroid glands in patients with primary hyperparathyroidism with promising results. However, the sensitivity of sestamibi and thallium to detect abnormal parathyroid glands is partly dependent on the gland size. In this study we compared the sensitivity of sestamibi subtraction scintigraphy with thallium subtraction scintigraphy in patients with predominantly mild increase in serum calcium level.METHODS: Thirty-nine patients with primary hyperparathyroidism were included. The mean (+/-SD) serum level of calcium was 2.75 +/- 0.17 mmol/L. In 28 (72%) of the patients the serum level of calcium was less than 2.85 mmol/L. These patients were classified as having mild abnormalities in serum calcium. All patients were investigated before operation with both sestamibi and thallium subtraction scintigraphy.RESULTS: In two patients autonomous thyroid adenomas precluded subtraction scintigraphy. Sestamibi subtraction scintigraphy correctly localized 31 (86%) of 36 parathyroid adenomas compared with only 17 (47%) of 36 by thallium subtraction scintigraphy (p < 0.001). There was one false-positive result in the sestamibi group because of a thyroid adenoma, and two of the scans were negative. Both the sestamibi and the thallium subtraction scintigraphy localized one single enlarged gland in all three patients with multiple gland involvement. In no case was multiglandular disease predicted.CONCLUSIONS: Sestamibi subtraction scintigraphy is superior to thallium subtraction scintigraphy and has a high sensitivity to localize a solitary parathyroid adenoma in patients with mild increase in serum calcium level. The sensitivity decreases in patients with multiglandular parathyroid disease and concomitant thyroid nodular abnormalities.
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| 4. |
- Bergenfelz, A, et al.
(author)
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Side localization of parathyroid adenomas by simplified intraoperative venous sampling for parathyroid hormone
- 1996
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In: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 20:3, s. 60-358
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Journal article (peer-reviewed)abstract
- Side localization of parathyroid adenomas was performed by venous sampling for intact parathyroid hormone (PTH) in 20 consecutive patients with primary hyperparathyroidism (pHPT) after induction of anesthesia. The results were thus available during surgery. Nineteen of the patients had solitary parathyroid adenoma, and one had hyperplasia. There was no complication to the procedure. A lateralizing PTH gradient for a parathyroid adenoma was obtained in 13 patients. At surgery 12 of them (92%) were proved correct; that is, the adenoma was localized on the same side. Thus the technique correctly lateralized the adenoma in 12 of 19 patients (63%). We therefore conclude that the method of intraoperative venous sampling for intact PTH is safe, and the predictive value of a lateralizing gradient is high. It could therefore be used as an adjunct to surgical skill and noninvasive localization procedures in selected cases, for instance in patients with prior neck surgery and hypercalcemic crisis.
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| 5. |
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| 6. |
- Bergenfelz, A, et al.
(author)
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Hyperthyroxinemia after surgery for primary hyperparathyroidism
- 1994
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In: Langenbecks Archiv für Chirurgie. - 0023-8236. ; 379:3, s. 81-178
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Journal article (peer-reviewed)abstract
- Episodes of transient thyrotoxicosis after surgery for primary hyperparathyroidism have previously been described, and surgical trauma to the thyroid gland has been suggested as an etiologic factor. However, there are several links between the thyroid and parathyroid hormonal systems, and therefore other explanations are possible as well. In this study we investigate pre- and postoperative serum levels of thyroid hormones in 20 patients operated upon because of primary hyperparathyroidism. The mean (SD) serum levels of T4 increased from 16(2) pmol/l preoperatively to 21(6) pmol/l on the fourth postoperative day (P < 0.01), and four (20%) of the patients developed biochemical thyrotoxicosis in the immediate postoperative period. The serum levels of T4 on the fourth postoperative day correlated highly with preoperative serum levels of PTH (r = 0.75; P < 0.001). This suggests that biochemical thyrotoxicosis in the immediate postoperative period after operation for primary hyperparathyroidism is not uncommon and could be related to the disease rather than to surgical trauma.
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| 7. |
- Bergenfelz, A, et al.
(author)
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Immunoheterogeneity of parathyroid hormone pre- and postoperatively in primary hyperparathyroidism
- 1995
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In: Langenbecks Archiv für Chirurgie. - 0023-8236. ; 380:2, s. 24-119
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Journal article (peer-reviewed)abstract
- In primary hyperparathyroidism (pHPT), a preferential release of intact PTH (i-PTH) versus carboxylterminal PTH fragments is known to occur. We studied whether the release of amino-terminal PTH fragments (N-PTH) is also changed. Serum levels of i-PTH and N-PTH were determined under basal conditions and following oral intake of calcium in six patients with pHPT before and immediately after surgery and in seven healthy subjects. In the patients, baseline levels of both i-PTH and N-PTH were increased preoperatively. The increase was larger in i-PTH compared to N-PTH. Therefore, the N/i ratio was reduced compared to healthy subjects (P < 0.05). On the first postoperative day, serum i-PTH decreased to a larger extent than N-PTH, which increased the N/i ratio above that in healthy subjects (P < 0.05). On the 5th postoperative day, the N/i ratio was normalized. Preoperatively, the suppressibility of i-PTH calcium was impaired in the patients (P < 0.05), whereas the suppressibility of N-PTH was normal, resulting in unchanged N/i ratio during the oral calcium load. In contrast, the N/i ratio increased normally during the calcium load at day 5 postoperatively (P < 0.05). We therefore conclude that: (1) in pHPT, circulating PTH immunoheterogeneity is altered with a preferential release of intact PTH compared to N-terminal PTH fragments and this alteration is normalized after surgery, (2) the secretion of intact PTH and N-terminal PTH shows different sensitivity to inhibition by calcium.
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| 8. |
- Bergenfelz, A, et al.
(author)
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Calcium metabolism after hemithyroidectomy
- 1993
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In: Hormone Research. - : S. Karger AG. - 0301-0163 .- 1423-0046. ; 39:1-2, s. 56-60
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Journal article (peer-reviewed)abstract
- It is not known whether thyroid surgery evokes changes in calcium metabolism. We therefore studied 6 patients operated upon with hemithyroidectomy for benign thyroid diseases, preoperatively and at 3 months and 1 year postoperatively. We measured changes in serum levels of intact parathyroid hormone (PTH), vitamin D metabolites, ionized calcium, phosphate, osteocalcin, thyroid hormones and bone density. Further, the dynamic function of the parathyroid glands was investigated by an oral calcium load test pre- and at 3 months postoperatively. At follow-up, all patients were euthyroid. During the oral calcium load, serum levels of intact PTH were reduced by the same degree before and after hemithyroidectomy, showing normal parathyroid function. Serum levels of 1,25-dihydroxyvitamin D declined from 86 +/- 16 to 57 +/- 4 pmol/l (p < 0.01) at 1 year after hemithyroidectomy, and serum levels of phosphate increased slightly from 0.96 +/- 0.08 to 1.06 +/- 0.08 mmol/l (p < 0.05), whereas serum levels of ionized calcium, intact PTH, osteocalcin and bone density did not change. Our results demonstrate that thyroid operation evokes changes in vitamin D metabolism in spite of normal parathyroid function.
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| 9. |
- Bergenfelz, A, et al.
(author)
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Functional recovery of the parathyroid glands after surgery for primary hyperparathyroidism
- 1994
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In: Surgery. - 0039-6060. ; 116:5, s. 36-827
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Journal article (peer-reviewed)abstract
- BACKGROUND: The immediate postoperative function of the parathyroid glands after surgery for primary hyperparathyroidism (pHPT) has not been established. We therefore examined the influences of hypercalcemia and hypocalcemia on serum parathyroid hormone (PTH) levels in the immediate postoperative period in patients with pHPT.METHODS: Ethylenediaminetetraacetic acid was infused in patients on the first (n = 5) and fourth (n = 6) postoperative days, and in patients at 1 year after surgery (n = 6), and in healthy subjects (n = 7). Calcium was given orally before operation and on the second and fifth postoperative days in six patients and in seven healthy subjects.RESULTS: The increased set point seen in pHPT was normalized on the first postoperative day, and the decreased PTH suppressibility by calcium was normal on the second postoperative day. However, on the fifth postoperative day an increased suppressibility of PTH was evident. During the ethylenediaminetetraacetic acid infusion test the secretory reserve for PTH increased after operation with increasing hypocalcemia-induced levels of intact PTH between the first and fourth postoperative days (p < 0.001), and between the fourth postoperative day and the test at 1 year (p < 0.05).CONCLUSIONS: In the immediate postoperative period after surgery for pHPT, baseline serum levels of PTH are rapidly normalized; this is followed by an increase in the secretory reserve for PTH secretion and the development of an increased sensitivity to calcium.
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| 10. |
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