Randomized clinical trial comparing regional and general anaesthesia in minimally invasive video-assisted parathyroidectomy.

BACKGROUND: This randomized clinical trial was performed in a single institution to compare the results of minimally invasive video-assisted parathyroidectomy (MIVAP) conducted under regional anaesthesia (RA) or general anaesthesia (GA). METHODS: Fifty-one patients undergoing MIVAP for primary hyperparathyroidism were assigned randomly to either RA (26 patients) or GA (25). RA involved a bilateral deep cervical block, and local infiltration of the incision site with a mixture of 0.25 per cent lignocaine and 0.15 per cent bupivacaine. GA was induced by intravenous administration of propofol, remifentanil and rocuronium bromide. RESULTS: The two groups were matched for age, sex, adenoma size, and preoperative serum calcium and parathyroid hormone levels. The interval from skin incision to closure was similar in the two groups (27.6 and 25.8 min for RA and GA respectively), whereas the total operating time (from induction of anaesthesia to return to the ward) was significantly lower with RA (72.1 versus 90.2 min; P = 0.001). The postoperative requirement for pain medication, measured in terms of amount of ketorolac administered at the request of the patient, was significantly lower in the RA group (28.5 versus 80 mg/day; P < 0.001). CONCLUSION: MIVAP performed under RA was associated with a shorter overall operating time and a reduced need for postoperative pain relief.

Radiofrequency ablation of regional recurrence from well-differentiated thyroid malignancy.

BACKGROUND: Regional recurrence of well-differentiated thyroid cancer (WTC) is primarily detected with ultrasonography (US), and current treatment is surgical. Radiofrequency ablation (RFA) has been used primarily for liver tumors as an alternative to a surgical procedure. We have applied RFA to a group of patients with locally recurrent WTC. METHODS: Eight patients underwent percutaneous RFA for biopsy-proven recurrent WTC in the neck (mean size, 2.4 cm; range, 0.8-4.0 cm) while under intravenous conscious sedation and with US guidance. The RF electrode was inserted into the site of recurrence and treated with the maximum allowable current for between 2 and 12 minutes. Follow-up consisted of US in 8 patients, thyroglobulin levels in 6 patients, biopsy in 4 patients, and surgical treatment in 2 patients. RESULTS: All 8 patients with no bleeding or infectious complications were treated as outpatients. A minor skin burn and 1 vocal cord paralysis occurred. No recurrent disease at the treatment site was detected, with a mean follow-up of 10.3 months. Histological examination showed no evidence of a tumor in the treated lymph nodes in 6 patients. Follow-up US examinations showed disappearance of previously detected color Doppler flow, as well as mass shrinkage and internal cystic change, or both. CONCLUSIONS: US-guided RFA is an exciting new treatment modality that appears to have a future role in treating locally recurrent WTC.

Minimally invasive video-assisted parathyroidectomy: multiinstitutional study.

Unilateral and minimally invasive parathyroidectomies with endoscopic and video-assisted technique have been introduced. Most of these procedures utilize preoperative localization and intraoperative monitoring of parathyroid hormone. There are only a few reports on these procedures. The objective of this study was to evaluate video-assisted parathyroidectomy (MIVAP) for surgery in patients with primary hyperparathyroidism (pHPT). From February 1997 to June 1999 a series of 123 consecutive patients with pHPT at four surgical centers were evaluated. The patients' ages ranged from 18 to 77 years (median 50 years). Preoperatively, sestamibi scintigraphy and ultrasonography for localization were performed for all patients. Selection criteria for a MIVAP procedure excluded patients with negative localization, suspicion of multiglandular disease (MGD) or thyroid malignancy, a large thyroid mass, and prior surgery or irradiation to the neck. MIVAP was performed with a 1.5 cm suprasternal incision; the operation was then done through this incision with a 30 degree 5 mm endoscope and microsurgical instruments with brief CO2 insufflation for adenoma identification. We then proceeded with an open technique through the small incision under video-assistance. Intraoperative monitoring of intact parathyroid hormone (iPTH) assays was used in all patients. Among the 123 patients in whom MIVAP was attempted, the procedure was accomplished in 109 (89%). Conversion to conventional cervicotomy was required in 14 (11%) patients because of failed localization, failure of the iPTH level to fall appropriately, or technical problems. There was no persistent or recurrent HPT during the 3 to 12-month follow-up. Oral calcium replacement for symptomatic hypocalcemia postoperatively was given in 7 (6%) cases. A unilateral transient laryngeal nerve palsy, resolving within 6 months postoperatively, occurred in two (2%) patients. The median hospital stay was 1.5 days (range 0.5-5.0 days). This study showed the feasibility of MIVAP as an alternative surgical treatment for pHPT in a selected group of patients. Further studies are necessary to evaluate the efficacy and rationale of MIVAP compared to other techniques for parathyroidectomy in pHPT patients.

Occult papillary carcinoma of the thyroid presenting as a cervical cyst.

BACKGROUND: A cystic neck mass representing metastatic papillary thyroid cancer to a cervical lymph node may be the presenting symptom in patients with an occult papillary cancer of the thyroid. This cystic change can cause diagnostic problems and not infrequently delay identification of the primary thyroid tumor. This study investigates the frequency, treatment, and pathologic features of this entity. METHODS: All clinical charts and microscopic slides of 136 consecutive patients who underwent thyroid operation for papillary carcinoma (PC) from 1990 to 1995 were reviewed. Hematoxylin-and-eosin and immunohistochemical stains (IMHS) for thyroglobulin also were reviewed. RESULTS: Eight patients (5.8%) presented with a cystic neck mass and no palpable thyroid lesion. In all 8 patients, the diagnosis was made by an excision of the cystic neck mass. In 3 patients, the cyst demonstrated classical features of PC, such as papillae and psammoma bodies. In the remaining 5 (62%), only focal papillae or nuclear features of papillary carcinoma were present. A careful review of the histology and IMHS were necessary to arrive at the correct diagnosis in these 5 patients. CONCLUSIONS: Occult papillary cancer of the thyroid presenting as a cystic neck mass is not uncommon and must be considered in the differential diagnosis. Excision and careful review of the histology and IMHS is necessary to prevent delay of the proper diagnosis. Although the thyroid tumor was less than 1 cm and sometimes only microscopic, the extensive nodal metastasis has led us to favor near total or total thyroidectomy and modified neck dissection in this entity.

Pre-operative localization of parathyroid adenomas: a comparison of power and colour Doppler ultrasonography with nuclear medicine scintigraphy.

AIM: To compare power and colour Doppler ultrasonography (US) with nuclear medicine scintigraphy (NM) in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT). MATERIALS AND METHODS: Thirty-one patients with biochemical evidence of PHPT underwent pre-operative US and NM for parathyroid adenoma localization. Both studies were interpreted independently without prior knowledge of the other study's findings. All patients had surgical removal of the parathyroid adenoma utilizing standard neck exploration or minimally invasive unilateral surgical techniques with rapid serum assay of circulating parathyroid hormone levels. RESULTS: All patients had single parathyroid adenomas at surgery. Prospective sensitivities for US, NM and both studies combined were 65%, 68%, and 74%, respectively, with a positive predictive value of 100% each. The adenoma was localized by only one imaging modality in 16% of cases. CONCLUSIONS: US and NM provide complementary roles in the pre-operative localization of parathyroid adenomas in patients with PHPT.

The necessity for a thoracic approach in thyroid surgery.

HYPOTHESIS: A thoracic approach is commonly required in certain subsets of patients with a mediastinal thyroid mass. DESIGN: A retrospective review. SETTING: A tertiary referral center. PATIENTS: Nine hundred seventy-six consecutive patients who underwent thyroid surgery by a single surgeon from June 1, 1991, to March 30, 1999. Symptoms of airway compression, including respiratory distress, dyspnea, hoarseness, dysphagia, and persistent cough, were the most common presenting symptoms. The patients ranged in age from 27 to 89 years (mean, 63 years). RESULTS: Patients in whom the computed tomographic scan and operative findings revealed that at least 50% of the thyroid mass was below the thoracic inlet were considered to have a mediastinal mass. These strict criteria identified 94 patients with a mediastinal thyroid mass. Twenty-seven (29%) of these patients required a thoracic approach. The thoracic approach consisted of 21 partial sternotomies, 5 full sternotomies, and 1 right posterolateral thoracotomy. Fifteen patients had a malignant neoplasm. Fourteen patients had a papillary carcinoma, and 3 of these patients had a multifocal microscopic papillary carcinoma within a multinodular colloid goiter. One patient had a follicular carcinoma. Seven patients underwent reoperative surgery, 5 for a malignant tumor and 2 for a benign tumor. Five patients had a posterior tumor, and 2 had an aberrant mediastinal thyroid mass. Twenty-two (81%) of the 27 patients who underwent a thoracic approach fell into one of the following categories: malignant neoplasm, reoperation, or aberrant or posterior mediastinal thyroid mass. CONCLUSIONS: Subsets of patients with a mediastinal thyroid mass are at considerably increased risk for requiring a thoracic surgical approach. These subsets include patients with malignant mediastinal tumors, patients undergoing reoperative thyroid surgery, and patients with posterior or aberrant mediastinal thyroid masses. Surgeons should be prepared for the increased likelihood of a thoracic approach in these subsets of patients.

Minimally invasive parathyroid surgery.

BACKGROUND: Minimally invasive access for the treatment of primary hyperparathyroidism is becoming widespread, but several different approaches have been proposed in the literature. METHODS: We describe the three main types of mini-invasive parathyroidectomy, with particular attention to the gasless video-assisted procedure, which is now routinely performed at our institution. RESULTS: Eighty-nine patients with a preoperatively localized single adenoma were successfully treated. Operative time was 58 mins, and there were only five conversions. DISCUSSION: After comparing the different approaches described in literature, we conclude that mini-invasive parathyroidectomy is feasible and can provide additional benefits not available with traditional surgery. At present, however, this operation can be recommended only for patients with sporadic disease, localized lesions, and absence of goiter and prior neck surgery.

Subcutaneous forearm transplantation of autologous parathyroid tissue in patients with renal hyperparathyroidism.

BACKGROUND: Parathyroidectomy is required in up to 5% of patients with chronic renal failure. Intramuscular transplantation of autologous parathyroid tissue in the forearm has been the traditional method of transplantation at the time of total parathyroidectomy. The removal of an intramuscular transplantation can be technically difficult should graft-dependent hyperparathyroidism (GRH) occur. This problem resulted in our initiating a study of subcutaneous transplantation with total parathyroidectomy in patients with renal failure. METHODS: Twenty-six patients who were receiving dialysis therapy underwent total parathyroidectomy and subcutaneous transplantation. Parathyroid tissue was diced into 1- to 2-mm pieces, and 6 pieces were grafted into 6 subcutaneous pockets of the forearm. Intact parathyroid hormone was measured within 48 hours of operation and in the bilateral antecubital veins 1 to 24 months after the operation to assess completeness of resection and graft function, respectively. RESULTS: No major surgical complications occurred. Symptoms improved in 24 patients (85%). Graft failure rate was 4.3%. No GRH was observed. Follow-up was 4 to 55 months (mean, 27 months). CONCLUSIONS: This study indicates that the subcutaneous transplantation function is comparable to intramuscular transplantation and suggests a decreased incidence of GRH. Subcutaneous transplantation is technically easier than intramuscular transplantation and has the additional advantage of easy removal should GRH occur.

Role of surgery in stage IE non-Hodgkin's lymphoma of the thyroid.

BACKGROUND: Controversy persists regarding the role of surgery in the treatment of stage IE non-Hodgkin's lymphoma of the thyroid. Treatment options vary from complete surgical resection only to needle biopsy as the only invasive procedure required. METHODS: During a 29-year period 15 patients with stage IE non-Hodgkin's lymphoma were treated, with complete follow-up available in all patients. All patients had surgical exploration, followed in most cases by radiation therapy and/or chemotherapy. RESULTS: After operation six patients exhibited no gross residual tumor, all with intrathyroid disease, and all remained disease free; five of nine patients with residual disease, all with extrathyroid lesions, had persistent or recurrent disease (p < 0.04). Among patients with residual disease after operation five of six receiving postoperative radiation therapy exclusively have died of or had recurrence of disease, whereas no further persistent or recurrent disease occurred in the three patients who received adjuvant chemotherapy (p < 0.02). CONCLUSIONS: Surgery permitted the distinction between intrathyroid tumor, which may be treatable by local therapy alone, and extrathyroid lesions, which appear to require systemic chemotherapy. Surgery provides not only the same diagnostic ability as needle biopsy but also important therapeutic implications regarding adjuvant therapy.

Color Doppler sonography: an adjunctive technique in assessment of parathyroid adenomas.

In evaluating primary parathyroid adenomas with high-resolution color Doppler sonography, initial detection relied on the observation of a hypoechoic soft tissue mass adjacent to the thyroid gland. Using color Doppler sonography, many adenomas had a demonstrable blood supply from the inferior thyroidal artery branches, identified as a vascular arc surrounding the gland from 90 to 270 degrees. The vascular arc assists the interpreter with establishing the nature of the mass, differentiating it from masses such as regional lymph nodes, which demonstrate hilar flow. Sixty-three percent (20 of 32) of parathyroid adenomas had a color arc. The identification of a vascular arc is a useful adjunctive finding, improving diagnostic specificity and quickly confirming the diagnosis of parathyroid adenoma.

Role of the oral calcium-loading test with measurement of intact parathyroid hormone in the diagnosis of symptomatic subtle primary hyperparathyroidism.

BACKGROUND: This study was designed to assess the diagnostic value of the oral calcium tolerance test with measurement of intact parathyroid hormone by the immunoradiometric assay (IRMA PTH) in the diagnosis of primary hyperparathyroidism in patients with symptoms who have minimal, intermittent, or no elevation of the levels of total calcium and/or intact PTH. METHODS: After baseline levels of IRMA PTH and total calcium were measured, an oral calcium load of 1000 mg elemental calcium was administered to 10 patients with hyperparathyroidism and 18 normal control subjects. Total calcium and IRMA PTH levels were measured at 30, 60, and 120 minutes after the oral calcium load was administered. RESULTS: The mean suppression of the baseline level of IRMA PTH in the patients with hyperparathyroidism was 83.7% +/- 6.5% (mean +/- 1 SEM), but the levels of the normal control subjects fell significantly (p < 0.05) lower to 58.8% +/- 3.7% (mean +/- 1 SEM). CONCLUSIONS: This study suggests that the oral calcium tolerance test may be a valuable adjunct in confirming the diagnosis of primary hyperparathyroidism in patients with symptoms who have minimal, intermittent, or no elevation of the levels of total calcium and/or IRMA PTH:

Management of Cushing's syndrome secondary to adrenal adenoma during pregnancy.

This report discusses our experience with two patients who had unilateral adrenalectomy during pregnancy as treatment for Cushing's syndrome secondary to an adrenal adenoma. Previously only five patients with this clinical problem who underwent unilateral adrenalectomy during pregnancy had been reported. We have reviewed the world literature on Cushing's syndrome in pregnancy secondary to an adrenal adenoma. A total of 19 patients who had unilateral adrenalectomy for this problem after the completion of pregnancy were identified. The review of world literature and the two patients who are the subject of this report were the basis of our analysis of fetal death, neonatal complications, and maternal complications in seven pregnancies during which unilateral adrenalectomy was performed (group 1) compared to the 19 pregnancies that were associated with unilateral adrenalectomy at the completion of pregnancy (group 2). Of the seven pregnancies in group 1, one fetal death and no neonatal complications occurred, but fetal death and neonatal complications occurred in 12 of the 19 pregnancies in group 2. Four of the seven mothers in group 1 had complications; 16 of the 19 mothers in group 2 had complications. This study suggests that adrenalectomy during pregnancy should be considered as a therapeutic option in the management of Cushing's syndrome secondary to an adrenal cortical adenoma.

Pentagastrin stimulation of calcitonin in pheochromocytoma does not always indicate multiple endocrine neoplasia type II.

The diagnosis of pheochromocytoma in a 48-year-old man was confirmed by elevated catecholamine secretion and a left adrenal mass on computerized tomography. Because of a plausible family history for Multiple Endocrine Neoplasia Type II, a calcitonin level was determined which was elevated, and pentagastrin stimulation caused a 235% increase. These findings normalized following surgical removal of the single adrenal tumor. It is concluded that pentagastrin stimulation of calcitonin is not necessarily diagnostic of medullary thyroid carcinoma, and such a response in a patient presenting with pheochromocytoma may not indicate underlying Multiple Endocrine Neoplasia Type II.

A comparative study of serum ultrafiltrable, ionized, and total calcium in the diagnosis of primary hyperparathyroidism in patients with intermittent or no elevation in total calcium.

Measurement of serum ionized calcium has been shown to be more sensitive a method of diagnosing primary hyperparathyroidism than total calcium in patients with subtle or intermittent elevations of total calcium. The measurement of ionized calcium, however, is technically difficult. The measurement of serum ultrafiltrable calcium would circumvent technical difficulties because atomic absorption spectroscopy would be used to measure the calcium of a filtrate produced by passing serum through a filter which excludes protein-complexed calcium (Worthington ultrafree filter). The normal range for ultrafiltrable calcium (4.7 to 6.8 mg/dl) was determined in 138 patients by nonlinear least-squares analysis and chart review. The serum concentration of ultrafiltrable calcium correlated well with ionized calcium (r = 0.91). Previous studies have demonstrated no benefit in measuring ionized calcium, as opposed to total calcium, in the diagnosis of primary hyperparathyroidism unless there was subtle, intermittent, or no elevation of the total calcium. This comparative study of ultrafiltrable, ionized, and total calcium was, therefore, done in six patients with primary hyperparathyroidism who exhibited intermittent, minimal, or no elevations in serum total calcium. All six patients had symptoms referrable to hyperparathyroidism. All six underwent parathyroid surgery, and a parathyroid adenoma was found in each case. These six patients had a total of 24 concurrent preoperative determinations of ionized, ultrafiltrable, and total calcium levels. The total calcium value was elevated in only 9 of these 24 determinations (38%), ultrafiltrable calcium was elevated in 15 (63%), and ionized calcium was elevated in 23 (96%). The values of ionized calcium were elevated more frequently than both total calcium (p less than 0.0005) and ultrafiltrable calcium (p less than 0.025). The values for ultrafiltrable calcium were more frequently elevated than those for total calcium; this difference, however, was not significant. This study confirms our previous reports showing that ionized calcium is a more sensitive indicator of primary hyperparathyroidism in patients with intermittent or borderline elevation of the total calcium and extends those observations to show that ionized calcium is also a more sensitive indicator of primary hyperparathyroidism than ultrafiltrable calcium in this group of patients.

Solitary parathyroid microadenoma.

In our experience with operations for primary hyperparathyroidism, a recurring problem centers on patients whose solitary adenomas are too small to be appreciated at the initial exploration. We have seen four patients with parathyroid microadenomas, which we define as lesions less than 6 mm in diameter in externally undeformed parathyroid glands. Two such patients were fortuitously cured at the initial exploration even though the operative findings were inconclusive. One, a 25-year-old man, underwent excision of an externally normal gland that contained a 3 by 2 by 2 mm microadenoma. He is eucalcemic since the operation. The other patient, a 70-year-old woman with hypercalcemia, responded to prednisone. She then underwent a neck exploration at which the diagnosis of sarcoidosis was confirmed by lymph node biopsy examination. A 4 by 2 by 2 mm parathyroid microadenoma was incidentally removed. The patient is normocalcemic receiving low-dose steroid treatment since the operation. In a third patient, a 34-year-old practical nurse, three explorations were needed to find a parathyroid gland, which was negative for adenoma on frozen-section microscopy. The solitary adenoma, 6 by 3 by 3 mm, was appreciated only on permanent sections. The majority of oxyphil microadenomas should be suspected to be nonfunctioning, as in a 59-year-old woman in whom the lesion coexisted with primary chief cell parathyroid hyperplasia. The hyperparathyroidism responded well to three and a half-gland resection. The 2 by 2 by 2 mm oxyphil adenoma was also removed. Solitary parathyroid adenomas can be subtle and small. Appraisal of parathyroid disease at the operating table is not always straightforward. As more patients with early hyperparathyroidism appear on routine calcium screening, we may expect to see increasing numbers of challenging solitary parathyroid microadenomas.

The role of ionized calcium in the diagnosis of subtle hypercalcemia in symptomatic primary hyperparathyroidism.

This report details our continued study of the role of ionized calcium (CAI) in the diagnosis of symptomatic primary hyperparathyroidism (HPT) in patients with persistently normal total serum calcium (CAT) or fluctuating normal total serum calcium levels with elevated CAT. A patient was considered to have fluctuating CAT values if at least 40% of the CAT values were within the normal range. Our previous study demonstrated that CAI provided no additional diagnostic benefit in patients with HPT who had persistently elevated CAT levels. This retrospective study adds 15 additional patients to the four previously reported patients whose workup for HPT included normal or fluctuating normal total serum calcium with elevated CAT values. Eighteen of these 19 patients had complications or symptoms referable to HPT. Nine of these patients had renal calculi. CAT was measured by atomic absorption spectroscopy and CAI was measured by a calcium-selective ion flow-through electrode. One hundred fifty-one concurrent preoperative measurements of CAT and CAI from these 19 patients were used for analysis. Overall, 46 (30.5%) of the CAT values were elevated, whereas 134 (88.7%) of the concurrent CAI values were elevated (P less than 0.001). In three of these 19 patients all preoperative CAT values were within normal limits, however, 20 of the 21 (95%) concurrent CAI values were elevated. In the remaining 16 patients the CAT values fluctuated between normal and elevated. In all of these patients, at least 40% of the preoperative CAT values were normal, and in 15 of these 16 patients at least 50% of the preoperative CAT values were within the normal range. In this fluctuating category there were 130 concurrent values of CAT and CAI. Only 46 of these 130 (35.4%) CAT values were elevated, whereas 114 of the 130 (87.7%) CAI values were elevated (P less than 0.001). All patients underwent parathyroid operation; 15 patients had a parathyroid adenoma and four had hyperplasia. The CAI and CAT values returned to normal in all patients subsequent to operation. These data indicate that the measurement of serum ionized calcium appears to play an important role in the identification of symptomatic HPT in patients who have normal or fluctuating normal total serum calcium with elevated CAT values.