[Intraoperative intact parathyroid hormone determination as a predictive factor of hyperparathyroidism resolution]

[Primary hyperparathyroidism and acute toxic hypercalcaemic crisis]

OBJECTIVES

To describe the clinical characteristics and surgical treatment of patients with acute hypercalcaemia due to primary hyperparathyroidism (PHPT) and compare them with other patients with PHPT without associated acute hypercalcaemia.

MATERIAL AND METHODS

A prospective, observational study (1998-2010) was conducted on 158 patients with PHPT treated by parathyroidectomy. Those with acute hypercalcaemia (>14 mg/dl -3.5 mmol/L- or >3 mmol/L with symptoms of calcium toxicity) were evaluated by recording their clinical and treatment characteristics, and comparing them, using the Mann-Whitney U test and the Fisher test, with the 146 PHPT patients without hypercalcaemic crisis.

RESULTS

Twelve patients (7.6%) had acute hypercalcaemia with symptoms of calcium toxicity and other symptoms of chronicity. The preoperative calcium and PTH values were 14.5 ± 1.3mg/dL and 648.2 ± 542 pg/dL, respectively. There were 10 adenomas, 1 hyperplasia and 1 carcinoma. The mean weight of the surgical pieces was 4.075 ± 2.918 mg, with a diameter greater than 27 ± 14 mm. The gradients of PTH at 10 and 25 minutes were 79 ± 18% and 92 ± 6%, respectively. Post-operative calcium values on discharge and at 6 months were 8.2 ± 0.7 mg/dL and 9.1 ± 0.9 mg/dL, respectively. The plasma concentrations of calcium, PTH, and the size of the surgical pieces were higher in patients with hypercalcaemic crisis (P<0.001). There were no differences in the other parameters studied or in the cure rate.

CONCLUSIONS

Hypercalcaemic crises were caused by larger and heavier tumours that led to higher plasma Ca and PTH plasma concentrations. All patients had long-standing symptoms and parathyroidectomy led to cure of the disease.

[Relationship between parathormone concentration during surgery and the post-operative outcome of primary hyperparathyroidism]

INTRODUCTION

The relationship between the intra-operative concentration of parathyroid hormone (IOPTH) and the long-term outcome of patients intervened due to primary hyperparathyroidism (PHPT).

PATIENTS AND METHODS

A prospective observational study was performed with 120 patients. Three determinations were made of PTH in blood: baseline, when the diseases gland was located, and 10 minutes after its extirpation. The calcium, PTH and vitamin D (25-OH-D3) levels were measured during follow up.

RESULTS

A decrease in IOPTH > 50% was observed in 96 (80%) patients, and the post-extirpation value returned to the normal range (Group I), in 18 (15%) a decrease of > 50% but the final value remained higher than normal (Group II) and in 6 (5%) the decrease was<50% (Group III). Persistent PHPT was detected during follow up in 6 patients (5%): one in Group I (1%), 3 (16.7%) in II and 2 (33.3%) in group III (P<.001). The risk of persistent PHPT was higher in Group II (odds ratio: 19; 95% CI: 1.85-194) and in Group III (odds ratio: 47; 95% CI: 3.53-639). There were no cases of recurrent PHPT. A normal calcium with an increased PTH was detected in 20 patients of Group I (20.8%), 11 (61.1%) in II and 3 (50%) in III (P<.001). These patients had a lower concentration of post-operative vitamin D (17 ng/ml, range: 24; compared to 28 ng/ml, range: 21) (P=.008) and higher frequency of hypovitaminosis D (70.6% compared to 26.2%) (P>.001).

CONCLUSION

The risk of persistent PHPT is higher when the IOPTH decreases more than 50% but still remains high.

[Utility of methoxy isobutyl isonitrile (MIBI) scintigraphy, ultrasound and computerized axial tomography in preoperative topographic diagnosis of hiperparathyroidism]

OBJECTIVES

1. To assess the sensitivity of scintigraphy using methoxy isobutyl isonitrile (MIBI). 2. To compare its resolution with that of ultrasound (US) and computerized axial tomography (CAT). 3. To use its diagnostic reliability to determine whether selective approaches can be used to treat hyperparathyroidism (HPT).

PATIENTS AND METHOD

A study of 76 patients who underwent surgery for HPT between 1996 and 2005 was performed. MIBI scintigraphy and cervical US were used for whole-body scanning in all patients; CAT was used in 47 patients. Intraoperative and postoperative biopsies were used for final evaluation of the tests, after visualization and surgical extirpation.

RESULTS

The results of scintigraphy were positive in 65 patients (85.52%). The diagnosis was correct in all of the single images. Multiple images were due to hyperplasia and parathyroid adenomas with thyroid disease (5.2%). Three images, incorrectly classified as negative (3.94%), were positive. The sensitivity of US was 63% and allowed detection of three MIBI-negative adenomas (4%). CAT was less sensitive (55%), but detected a further three MIBI-negative adenomas (4%).

CONCLUSIONS

1. The sensitivity of MIBI reached 89.46%. In the absence of thyroid nodules, MIBI diagnosed 100% of single lesions. Pathological thyroid processes produced false-positive results (5.2%) and there were diagnostic errors (4%). 2. MIBI scintigraphy was more sensitive than US and CAT. 3. Positive, single image scintigraphy allows a selective cervical approach. US and CAT may help to save a further 8% of patients (with negative scintigraphy).