Israel Medical Association Journal

Background: Direct aspiration from suspected pathological tissue and rapid parathyroid hormone analysis may offer a reliable, cost effective alternative to currently used “gold standard” tests.

Objectives: To validate the accuracy of intraoperative measurements of parathyroid hormone levels in parathyroid adenomas.

Methods: A prospective study included 22 patients diagnosed with primary hyperparathyroidism who underwent parathyroidectomy due to an adenoma or hyperplasia. Aspirations of tissues extracted from three adjacent areas (the pathological parathyroid, thyroid, and muscle tissues) were sent for rapid parathyroid hormone analysis. The assay values of these tissue aspirates were compared to the results of the pathology report based on frozen section analysis and the final pathology report.

Results: All assay results were significantly higher for parathyroid tissue 16,800 to 1,097,986 pmol/L (median 26,600), than for either thyroid 1.7 to 415 pmol/L (median 6.5), P < 0.001, or muscle tissue 1.1 to 1230 pmol/L, (median 11.3), P < 0.001. All tissues showing high parathyroid assay values were also verified by pathology examinations: 7 had adenomas and 15 had a differential diagnosis of adenoma or hyperplasia. The frozen section identified all but one (false negative). Rapid intraoperative parathyroid levels > 1500 predicted parathyroid tissue with a 99% level of confidence, while levels between 1000 and 1500 predicted it with 95% confidence. The intraoperative parathyroid hormone assay showed > 70% decrease in 15/21 cases.

Conclusions: Rapid intraoperative parathyroid hormone analysis is a reliable and precise technique, equally accurate for frozen section analysis in predicting with high certainty intraoperative parathyroid tissue.

Background: Hypocalcaemia following thyroid and parathyroid surgery is a well-recognized potential complication.

Objectives: To determine the utility of intraoperative quick parathormone assay in predicting severe hypocalcemia development following parathyroidectomy for a single-gland adenoma causing primary hyperparathyroidism.

Methods: A retrospective cohort study was performed. IO-QPTH[1] values were measured at time 0 (T0) before incision, and 10 (T10) and 30 minutes (T30) following excision of the hyperfunctioning gland. Percent decrease in IO-QPTH at 10 minutes (T10), maximum percent decrease of IO-QPTH value, and lowest actual IO-QPTH value obtained at surgery were used to determine any correlation with the development of postoperative hypocalcemia requiring treatment.

Results: Percent decrease in IO-QPTH at 10 minutes, maximum percent decrease in IO-QPTH and lowest IO-QPTH value did not correlate with the lowest postoperative calcium levels measured 18 hours after surgery (r = 0.017, P = 0.860 r = 0.018, P = 0.850 and r = 0.002, P = 0.985 respectively). For the purposes of our analysis, patients were subdivided into three groups. Group 1 comprised 68 patients with normal calcium levels (serum Ca 8.6¨C10.3 mg/dl) Group 2 had 28 patients with hypocalcemia (8.1¨C8.6 mg/dl) Group 3 included 12 patients with severe hypocalcemia (calcium level ¡Ü 8.0 mg/dl) requiring calcium supplementation due to symptoms of hypocalcemia. There was no difference between the three groups in the lowest IO-QPTH value (P = 0.378), percent decrease in IO-QPTH (P = 0.305) and maximum percent decrease in IO-QPTH (P = 0.142).

Conclusions: IO-QPTH evaluation was not useful in predicting the group of patients susceptible to develop severe postoperative hypocalcemia.  

[1] IO-QPTH = intraoperative quick parathormone

Objective: To evaluate the contribution of the sestamibi-SPECT (MIBI) localization, cervical ultrasonography, and intraoperative rapid turbo intact parathormone assay in minimal invasive parathyroidectomy.

Methods: Between August 1999 and March 2004, 146 consecutive hyperthyroid patients were treated using the MIBI and ultrasound for preoperative localization and iPTH[1] measurements for intraoperative assessment.

Results: Parathyroid adenoma was detected in 106 patients, primary hyperplasia in 16, secondary hyperplasia in 16, tertiary hyperplasia in 5 and parathyroid carcinoma in 1 patient. Minimal invasive exploration of the neck was performed in 84 of the 106 patients (79.2%) with an adenoma, and in 17 of them this procedure was performed under local cervical block anesthesia in awake patients. Adenoma was correctly diagnosed by MIBI scan in 74% of the patients, and by ultrasound in 61%. The addition of ultrasonography to MIBI increased the accuracy of adenoma detection to 83%. In 2 of the 146 patients (1.4%) iPTH could not be significantly reduced during the initial surgical procedure. Minimal invasive surgery with minimal morbidity, and avoiding bilateral neck exploration, was achieved in 79.2% of patients with a primary solitary adenoma.

Background: Among the various new technologies in the field of parathyroid surgery are intraoperative quick parathormone measurements.

Objectives: To evaluate the contribution of QPTH[1] measurements during parathyroidectomy to the achievement of higher success rates. 

Methods: QPTH assay using Immulite Turbo Intact PTH[2] was measured in 32 patients undergoing parathyroidectomy: 30 for primary and 2 for secondary hyperparathyroidism.  QPTH levels were measured at time 0 minutes (before incision) and at 10, 20, and 30 minutes after excision of the hyperfunctioning gland.  Only a drop of 60% or more from the 0’ level was considered to be a positive result.

Results: The mean QPTH level at time 0’ for PHPT[3] patients was 38.12 ± 25.15 pmol/L (range 9.1–118 pmol/L).  At 10 minutes post-excision of the hyperfunctioning gland (or glands), QPTH dropped by a mean of 73.80% to 9.89 ± 18.78 pmol/L. 

Conclusions: Intraoperative QPTH level measurement is helpful in parathyroid surgery.  A drop of 60% or more from 0’ level indicates a successful procedure, and further exploration should be avoided.

Background: Technetium-99m sestamibi scintigraphy has become one of the most popular techniques for localization of the parathyroid gland after failure of primary neck exploration.

Objective: To examine the efficacy of sestamibi with the hand-held gamma ray detecting probe for the identification of parathyroid adenomas during revision parathyroidectomy.

Methods: We reviewed six cases of probe-assisted neck exploration for parathyroid lesions following unsuccessful primary exploration.

Results: In all cases, the pathologic glands were successfully detected and removed.

Conclusions: With careful planning, a gamma ray detecting probe can be used optimally at 2–3 hours after technetium-99m sestamibi injection. The probe is efficient, easy and convenient to use.
 

Background: Primary hyperparathyroidism in elderly patients is usually associated with additional co-morbidity that increases operative risk, and thus many geriatric patients are denied the benefit of surgery for a single parathyroid adenoma.

Objectives:  To evaluate the safety and efficacy of accurate single photon emission computed tomography sestamibi scintigraphy, enabling precise localization of a single adenoma, in the geriatric population

Methods: Twenty-two patients aged 70 years and over with biochemically proven PHPT[1] and with a single parathyroid adenoma identified by localization studies (sestamibi SPECT[2] scan and ultrasonography) underwent 23 operations over 29 months (out of a total of 140 patients operated upon during the same period). Immediate preoperative sestamibi scintigraphy and marking of focal adenoma uptake followed by intraoperative hand-held gamma probe were used for the removal of the parathyroid adenoma by unilateral minimal access surgery. Associated major co-morbid conditions and pre- and postoperative calcium, phosphorus and parathormone levels were recorded. Indications for surgery were listed and operative and postoperative complications were noted. The patients were followed for a mean period of 17.7 months using the same parameters.

Results: The 22 patients with PHPT had a mean age of 76.3 ± 5.9 years (range 70–88 years)  and a female to male ratio of 13:9. Associated co-morbidity included ischemic heart disease (n=15), hypertension (n=22), non-insulin-dependent diabetes mellitus (n=9), chronic obstructive pulmonary disease (n=3), and previous neck surgery (n=3). Mean preoperative serum calcium, phosphorous and PTH[3] were 11.7 ± 1.3 mg/dl, 2.5 ± 0.5 mg/dl and 160.9 ± 75.4 pg/ml respectively. In 20 of the 22 patients, surgery was successful in curing PHPT (91%). One patient had persistent hypercalcemia due to a missed adenoma, and repeat operation (by focused minimal access surgery) was successfully performed 2 weeks later. There were no complications and no morbidity postoperatively. Mean postoperative serum calcium, phosphorous and PTH were 9.6 ± 1.2 mg/dl, 3.0 ± 0.5 mg/dl and 35.2 ± 24 pg/ml respectively. In all patients, serum calcium levels remained normal (9.7 ± 1.3 mg/ml) after long-term follow-up (mean 17.7 ± 9.6 months).

Conclusions: Minimally invasive, radio-guided focused parathyroidectomy for a single adenoma is a safe and effective method to cure hyperparathyroidism in the elderly. Success of surgery is directly related to the surgeon's experience and to the precise localization marking provided by sestamibi scintigraphic SPECT localization and concurrent sonographic findings.