Outpatient minimally invasive parathyroidectomy: a combination of sestamibi-SPECT localization, cervical block anesthesia, and intraoperative parathyroid hormone assay

Minimally invasive parathyroid surgery in 103 patients with local/regional anesthesia, without exclusion criteria

BACKGROUND

Parathyroid surgery for sporadic primary hyperparathyroidism (pHPT) can be accomplished with local/regional anesthesia and intraoperative monitoring of intact parathyroid hormone without exclusion criteria through a 1.0- to 1.25-inch (2.5- to 3.2-cm) incision (MIPL) in a high proportion of patients.

METHODS

One hundred thirty-one consecutive patients with pHPT were offered MIPL. One hundred three patients elected to have this procedure. Patients were not excluded because of inadequate localization, previous parathyroid surgery, or need for concomitant thyroid surgery. Preoperative localization with ultrasound and/or sestamibi-single photon emission computed tomography scan was done in all patients. Almost all patients had intraoperative monitoring of intact parathyroid hormone (IMPTH).

RESULTS

MIPL was accomplished in 89 of these 103 patients (86.4%), but 14 required conversion to general anesthesia. The main reasons for conversion were concomitant thyroid surgery, no positive preoperative localization, and previous parathyroid surgery. This procedure was accomplished in 13 patients requiring a bilateral procedure, 5 patients requiring thyroid surgery, 4 patients with no positive preoperative localization, and in 3 patients with previous parathyroid surgery. The complications of MIPL were comparable to the traditional bilateral exploration with general anesthesia. No patient experienced permanent hypoparathyroidism or postoperative bleeding. Two patients had transient recurrent laryngeal nerve paresis, and surgery failed to correct hypercalcemia in 5 (4.9%) of the patients. There appears to be less need for antiemetic medication in the MIPL patients compared with patients who had general anesthesia.

CONCLUSIONS

Parathyroid surgery for sporadic pHPT can be accomplished through a 1.0- to 1.25-inch (2.5- to 3.2-cm) incision with local/regional anesthesia, without exclusion criteria. Accurate preoperative localization, particularly localization to the same site by both ultrasound and 99mTc-sestamibi scan, and IMPTH can limit the surgery to a unilateral approach. One should be cautious in proceeding with MIPL in patients with need for concomitant thyroid surgery, no preoperative localization, or previous parathyroid surgery.

Medical and economic outcomes of point-of-care testing

Point-of-care testing is concerned with the immediacy of response, primarily because of the need to act in a life-threatening crisis or to provide counsel in the ongoing management of a chronic disease. There are both clinical, operational and economic benefits that can accrue from this testing modality which may be observed from several perspectives--the patient, the clinician, the healthcare provider, the healthcare purchaser and society. Thus point-of-care testing can improve the management of chronic diseases such as diabetes, compromised coagulation status and epilepsy--both in terms of optimisation of, and compliance with, therapy. There are also life-threatening crises that can be averted by rapid provision of test results. Each of these scenarios can lead to more efficient use of healthcare resources.

Minimally invasive parathyroidectomy using the 'focused' lateral approach. I. Results of the first 100 consecutive cases

BACKGROUND

A feasibility study of 'focused' minimally invasive parathyroidectomy (MIP) using a lateral approach was commenced in 1999. The aim of the present paper was to evaluate the effectiveness and safety of this procedure in the first 100 consecutive patients.

METHODS

This was a prospective, non-randomized case-control study. One hundred consecutive patients with primary hyperparathyroidism (mean age 63.1 years; 74 females, 26 males) who fulfilled the inclusion criteria underwent focused MIP between May 1999 and December 2000. The results for the first and last 50 consecutive patients were compared to see whether they were reflective of a learning curve. The role of intraoperative quick parathyroid hormone (QPTH) estimation was also evaluated.

RESULTS

Focused MIP was successfully completed in 93 of 100 patients, with seven conversions. Three (3.2%) of the 93 patients had persistent hyperparathyroidism. Quick PTH was measured in 81 patients and the results were true positive (for cure) in 72 patients, false negative in six patients, true negative in two patients and false positive in one patient. Transient recurrent laryngeal nerve paresis occurred in one patient. During the same time period, open parathyroidectomy was performed in 242 patients. The results were not different between the first and later 50 patients undergoing MIP, nor were the outcomes significantly different from patients undergoing open parathyroidectomy.

CONCLUSIONS

Focused MIP is a safe and effective operative approach for appropriately selected patients. Failed procedures were invariably related to shortcomings of the localization studies. Measurement of QPTH, although accurate, is unreliable in the presence of multigland disease.

Prospective evaluation of delayed technetium-99m sestamibi SPECT scintigraphy for preoperative localization of primary hyperparathyroidism

BACKGROUND

Delayed technetium-99m sestamibi single photon emission computed tomography (SPECT) scans were prospectively analyzed in a large series of patients with primary hyperparathyroidism.

METHODS

Three hundred thirty-eight patients underwent sestamibi-SPECT and were explored. Prospective data included preoperative demographics, clinical, sestamibi, and operative findings, laboratory values, and pathologic and follow-up laboratory results from all patients.

RESULTS

Between 1994 and 2000, 287 unexplored patients (85%) and 51 re-explored patients (15%) participated. The abnormal parathyroid glands excised from 336 of 338 patients included 299 single adenomas (88%) and 23 double adenomas (7%), and 14 patients had multigland hyperplasia (4%). Sestamibi SPECT correctly lateralized 349 of 400 abnormal parathyroid glands, with an overall sensitivity of 87%, an accuracy of 94%, and a positive predictive value of 86%. Precise localization occurred in 82% of the abnormal parathyroid glands. Sestamibi sensitivity was similar in unexplored (87%) and reoperative (92%) cases; two hundred eighty-six of 299 (96%) solitary adenomas, 38 of 46 (83%) double adenomas, but only 25 of 55 (45%) hyperplastic glands were identified. The mean weight of the true-positive glands (1252 +/- 1980 mg) was greater than that of the false-negative glands (297 +/- 286 mg) (P <.005). Three patients had persistent primary hyperparathyroidism, in spite of the excision of sestamibi-identified lesions in 2 cases. Follow-up indicated curative resection in 99% of the unexplored cases and 94% of the remedial cases.

CONCLUSIONS

Sestamibi SPECT is highly accurate for the localization of parathyroid adenomas in unexplored and re-explored cases, where it is often the only imaging required. Its sensitivity is limited in multiglandular disease.

Intraoperative quick parathyroid hormone versus same-day parathyroid hormone testing for minimally invasive parathyroidectomy: a cost-effectiveness study

BACKGROUND

Intraoperative quick parathyroid hormone (QPTH) measurement is claimed to eliminate failures during minimally invasive parathyroidectomy. The cost-effectiveness of QPTH (ie, true cost of avoiding a failed operation) needs careful evaluation.

METHODS

In 92 consecutive patients who underwent minimally invasive parathyroidectomy via a small lateral incision, QPTH was estimated preoperatively and at 5, 10, and 15 minutes postparathyroidectomy. QPTH results were subsequently compared with the procedure outcome. Cost-effectiveness analysis was performed for 3 subsequent theoretical management strategies: QPTH not performed, QPTH results available intraoperatively, and parathyroid hormone and serum calcium levels measured routinely with results made available the same day.

RESULTS

With criteria for cure being a decrease in the QPTH measurement to less than 50% of preoperative levels and to within normal range, QPTH predictions were true positive in 78 patients; false-negative in 7; false-positive in 1; and true negative in 2. The true cost of using QPTH measurement to avoid a failed operation was 19,801.19 US dollars, with 7 patients undergoing unnecessary conversion. Routine same-day parathyroid hormone and calcium measurements significantly reduced this to 624.73 dollars. Sensitivity analysis with varying cost assumptions demonstrated cost-effectiveness analysis to be robust.

CONCLUSIONS

The fact that 97% of patients will be cured regardless of QPTH testing combined with its false-negative rates significantly reduces the cost-effectiveness of the test when compared with same-day parathyroid hormone testing.

Minimally invasive, radioguided surgery for primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism affects 1 in 700 individuals in the United States. A single adenoma is responsible in over 85% of cases. Surgery remains the most effective treatment. This study was designed to assess the feasibility of minimally invasive radioguided parathyroidectomy (MIRP) with confirmation of excision by ex vivo radioactivity alone.

METHODS

Seventy-five consecutive patients with primary hyperparathyroidism were prospectively studied. Following sestamibi scan, patients underwent unilateral neck exploration guided by a handheld gamma probe, which was also used to measure ex vivo radioactivity of excised tissue.

RESULTS

The sestamibi scan was positive in 88% of the patients. A small incision (mean, 3.2+/-0.3 cm) was sufficient. Ectopic gland sites were localized in five patients with positive scans and single adenomas. Mean operative time was 48 minutes (range, 15-125 minutes), with shorter procedures after the initial 20 cases (mean, 24 vs. 72 minutes; P < .01). Radioguided parathyroidectomy was successful in 97%, with a mean follow-up of 11 months (range, 1-26 months). As noted previously, adenomatous parathyroid glands contained more than 20% of the background radioactivity.

CONCLUSIONS

MIRP is a feasible alternative to bilateral dissection with the advantages of guided dissection and rapid confirmation, and may become the procedure of choice for primary hyperparathyroidism.

Indications and results of video-assisted parathyroidectomy by a lateral approach in patients with primary hyperparathyroidism

BACKGROUND

Different minimally invasive techniques of parathyroidectomy have been described. We performed a retrospective study to evaluate the indications and results of video-assisted parathyroidectomy by lateral approach (VAPLA) in the management of our patients with primary hyperparathyroidism (PHPT).

METHODS

From December 1997 to December 2000, we operated on 293 patients with PHPT. VAPLA was proposed for patients with sporadic PHPT in whom a single adenoma was localized by means of sonography or sestamibi scanning, or both. VAPLA was performed on the anterior border of the sternocleidomastoid muscle. A quick parathormone (PTH) assay was used during the surgical procedures.

RESULTS

Of the 293 patients, 127 (43.3%) were not eligible for VAPLA: ipsilateral previous neck surgery (28 cases), associated nodular goiter (59 cases), suspicion of multiglandular disease (15 cases), no preoperative localization (17 cases), and miscellaneous causes (8 cases). VAPLA was performed in 166 patients (56.7%). Conversion to conventional parathyroidectomy was required in 26 patients (15.6%). Morbidity included 2 local hematomas, 1 definitive recurrent nerve palsy, and 4 capsular fractures. All of the 166 patients were normocalcemic, with follow-up ranging from 3 to 33 months.

CONCLUSIONS

VAPLA is safe and effective. It should be reserved for patients with sporadic PHPT, with a small single adenoma clearly localized preoperatively.

Minimally Invasive Parathyroidectomy without Intraoperative Localization

Minimally invasive parathyroidectomy (MIP) is gaining popularity as an alternative to traditional bilateral exploration for patients with primary hyperparathyroidism. The success of MIP relies on the ability of preoperative and intraoperative localization studies to guide a directed exploration for resection of a diseased gland. We hypothesize that excellent results can be achieved with MIP when only technetium-99m sestamibi (MIBI) is used for localization. We conducted a prospective analysis of all patients presenting with a biochemical diagnosis of primary hyperparathyroidism between January 1997 and November 2000. Patients meeting inclusion criteria were given a choice of MIP and directed exploration versus traditional bilateral exploration. Fifty patients chose MIP. Three patients who chose MIP had a negative MIBI, which left 47 patients in the primary study group. The MIBI correctly identified a parathyroid adenoma in 42 patients (89.3%). In two other patients MIBI was inaccurate; however, directed exploration was successfully converted to a bilateral exploration. Overall 44 of 47 (93.6%) patients in the study group were rendered normocalcemic after the initial operation. Three patients experienced persistent hypercalcemia and subsequently underwent successful bilateral exploration. Including those patients choosing a bilateral exploration, a total of 59 positive MIBI scans were evaluated. There were 54 true positives (positive predictive value 91.5%), and if all patients had chosen a MIP 94.9 per cent would have been successfully treated at the initial operation. Mean operative time for MIP was 54.6 minutes, and in 32 patients (68.1%) MIP was performed with local anesthesia and sedation. Twenty-six patients (55.3%) were discharged the same day of the procedure. There were no significant complications in any group analyzed. We conclude that MIP can be successfully performed on the basis of a positive MIBI scan. The present study highlighting many of the advantages of MIP questions the necessity of additional adjuncts such as intraoperative parathyroid hormone measurement and γ-probe localization.

Primary hyperparathyroidism: what every orthopedic surgeon should know

The diagnosis of hyperparathyroidism should rarely by missed by the orthopedic surgeon. When a patient presents with a pathologic fracture, routine serum calcium should be obtained. If there is evidence of elevated serum calcium or any of the pathognomonic findings of primary hyperparathyroidism on plain radiographs, total and ionized calcium and an intact parathyroid hormone levels should be obtained to make the diagnosis (Figure 5). When patients require surgical treatment for an orthopedic condition and also need surgery for hyperparathyroidism, the procedures can be safely performed simultaneously. Simultaneous parathyroidectomy corrects the underlying endocrinopathy, thereby improving the outcome of the orthopedic procedure. In addition, these procedures can easily be performed simultaneously under one anesthetic and thereby minimize cost and length of hospitalization.

Primary hyperparathyroidism

Treatment of primary hyperparathyroidism depends on a clear diagnosis based on biochemical confirmation. Most patients have an elevated serum total or ionized calcium level in association with an elevated or inappropriate serum intact parathyroid hormone level. The serum calcium level can be lowered by hydration and by a variety of pharmacologic agents. However, none of these agents is effective in the long-term management of primary hyperparathyroidism. The extraordinarily high success rate of surgery, combined with its low morbidity and the ever-increasing acceptance of minimally invasive techniques, makes surgical resection the recommended treatment for virtually all patients.

Can localization studies be used to direct focused parathyroid operations?

BACKGROUND

There is considerable controversy today concerning the most appropriate surgical approach for patients with primary hyperparathyroidism. The conventional surgical operation involves a bilateral neck exploration through a collar incision with identification of all parathyroid tissue and removal of abnormal parathyroid glands while the patient is under general anesthesia. The success rate of this operation is about 95% or greater in the hands of an experienced endocrine surgeon. Preoperative localization techniques are generally considered to be unnecessary before initial parathyroid operations. The purpose of this investigation was (1) to evaluate the individual and combined accuracy of ultrasonography and technetium 99m sestamibi scans in localizing abnormal parathyroid glands and (2) to determine whether such scans could be used to direct a focused operation.

METHODS

We retrospectively studied 338 patients with sporadic primary hyperparathyroidism who had preoperative neck localization studies, ultrasonography and/or technetium 99m sestamibi scans, and parathyroid exploration (238 patients or, reexploration, 60 patients) from January 1996 to April 2000 at the University of California San Francisco/Mount Zion Medical Center. The preoperative localization studies were recorded as true-positive, false-positive, and false-negative and compared with the surgical and pathologic findings and with the outcome of the operation.

RESULTS

All of the abnormal parathyroid glands were correctly identified by ultrasonography in 184 of 303 patients (60.7%) and by technetium 99m sestamibi scanning in 183 of 237 patients (77.2%). The sensitivities of ultrasonography and sestamibi were 65% and 80%, respectively. Among the 202 patients who received both ultrasonography and sestamibi scans, a parathyroid tumor was identified at the same site in 105 (52%) of them. When both techniques identified a parathyroid tumor at the same site, the tests were correct in 101 of 105 patients and the sensitivity increased to 96%.

CONCLUSIONS

When both the ultrasonography and sestamibi scans identified the same, solitary parathyroid tumor in patients with sporadic primary hyperparathyroidism, this was the only abnormal parathyroid gland in 96% of the patients. A focused parathyroidectomy could therefore be performed in such patients with an acceptable ( approximately 95%) success rate.

Evaluation of the Performance and Clinical Impact of a Rapid Intraoperative Parathyroid Hormone Assay in Conjunction with Preoperative Imaging and Concise Parathyroidectomy

Background: 99mTc-sestamibi scans and rapid, intraoperative intact parathyroid hormone (PTH) assays allow preoperative identification of diseased glands and intraoperative confirmation of diseased gland removal, respectively. Use of these two new technologies may facilitate simpler, more concise surgery, shorter hospital stays, and decreased costs for frozen-section analysis. One major drawback to this new strategy has been the high cost of rapid point-of-care PTH assays.

Methods: We performed rapid PTH assays with the DPC Turbo PTH assay on the DPC IMMULITE automated analyzer. The number of intraoperative frozen sections, type of anesthesia, surgical approach, length of hospital stay, and pre- and postoperative calcium values were compared between a group of 49 patients undergoing parathyroidectomy where the intraoperative PTH assay was used in conjunction with preoperative imaging, and a historical control group of 55 patients before the use of these two technologies in our institution.

Results: Comparison of the Turbo PTH assay to the standard IMMULITE PTH assay gave the following: y = 1.08x − 4.36 (r = 0.97; n = 48). For the 49 patients, the median turnaround time for each intraoperative PTH determination was 19 min (range, 14–40 min). The median decrease in PTH values from baseline was 88% (range, 33–99%). Thirty-seven patients required two PTH determinations, 7 required three, 4 had four, and 1 required five determinations. The average laboratory cost for the rapid intraoperative PTH assays was &lt;$100 per patient (range, $55 to $113). Compared with the control group, the experimental group had significantly fewer frozen sections (1.4 vs 2.5; P &lt;0.0001), shorter hospital stays (17 discharged on the day of surgery vs none discharged on the day of surgery; P &lt;0.0001), greater use of local anesthesia (33% vs 0%; P &lt;0.001), and more unilateral, rather than bilateral neck explorations (65% vs 0%; P &lt;0.001).

Conclusions: The combination of intraoperative Turbo PTH assay and preoperative 99mTc-sestamibi scans can lead to significant decreases in laboratory and surgical pathology costs, hospital stays, and exposure to general anesthesia by facilitating concise parathyroidectomy surgery.

Nonoperative management of hyperparathyroidism: present and future

Parathyroidectomy provides effective treatment for primary and secondary hyperparathyroidism with a predictable response of symptoms related to hypercalcemia and elevated parathyroid hormone. Calcium and vitamin D supplementation has reduced the need for parathyroidectomy in dialysis patients with secondary hyperparathyroidism. However, surgery continues to be the only effective treatment of primary hyperparathyroidism. Potential nonoperative treatments for hyperparathyroidism have included the use of estrogen replacement, bisphosphonates, and a new class of drugs known as calcimimetics. Hormone replacement therapy with estrogen has been reported to improve cortical bone density in postmenopausal women with asymptomatic or mildly symptomatic primary hyperparathyroidism. Calcimimetic agents are a new class of drugs that increase the sensitivity of the calcium receptor to ionized calcium. Initial studies have shown that calcimimetics can acutely lower parathyroid hormone levels in patients with primary and secondary hyperparathyroidism. These drugs are currently being evaluated in phase II clinical trials. Ultimately, these medical modalities will need to be compared to parathyroidectomy in randomized controlled clinical trials.

An initial experience with radioguided parathyroid surgery

BACKGROUND

Recent reports have shown the effectiveness of preoperative parathyroid scintiscanning as an aid to parathyroidectomy. Less attention has been paid to limitations of this approach based on patient characteristics.

METHODS

All patients evaluated for primary hyperparathyroidism by an endocrine surgeon from December 1, 1998, through October 31, 1999, were retrospectively reviewed. Data were gathered to determine which patients were candidates for the radioguided approach, the effectiveness of this approach, and the reasons why some patients were not candidates for this approach.

RESULTS

Thirty-three patients were evaluated. Based on history, 4 patients were not candidates for a radioguided approach. Of the remaining 29 patients, 19 had positive sestamibi scans (65.5%) and successful radioguided operations. The 10 patients (34.5%) with negative scans had successful standard parathyroidectomy.

CONCLUSION

Although radioguided parathyroid surgery is an effective surgical approach, only 57.6% of patients in this series could have a radioguided operation. Standard four-gland exploration will continue to be needed for many patients.

Late parathyroid function after successful parathyroidectomy guided by intraoperative hormone assay (QPTH) compared with the standard bilateral neck exploration

BACKGROUND

Controversy continues between bilateral neck exploration and limited parathyroidectomy. One approach depends on gland size and histopathologic factors; the other approach limits excision to only hypersecreting glands. Both have excellent early operative success, but late recurrence rates with limited exploration are unknown.

METHODS

Three hundred twenty consecutive patients with primary hyperparathyroidism were followed 6 to 313 months after successful parathyroidectomy. One hundred seventy-six patients had bilateral neck exploration with excision of enlarged glands (group I); 144 patients had glands excised based on hyper-secretion (group II). Calcium and intact parathyroid hormone (iPTH) levels were measured yearly. Parathyroid gland hypersecretion was determined by elevated iPTH levels.

RESULTS

In group I, 1 gland was excised in 160 patients (91%); 19 of 176 patients (11%) had elevated iPTH levels. In group II, 139 patients (97%) had 1 gland excised; 19 of 144 patients (13%) had high iPTH levels. The number of patients with more than 1 gland excised in group I (9%) is 3 times higher than in group II (3%) (P <.05). There was no significant difference in the incidence of recurrent hyperfunctioning glands between the 2 different operative approaches (chi-squared test).

CONCLUSIONS

Late parathyroid gland function was comparable with both approaches. Multiple gland excision based on size alone may lead to excision of normal functioning glands.

Intraoperative Parathyroid Hormone Analysis: A Study of 200 Consecutive Cases

Background: Immunoassays for parathyroid hormone (PTH), with short incubation times and results available in &lt;15 min, have allowed intraoperative monitoring of the success of parathyroid surgery. The purpose of this study was to evaluate the analytical performance of a rapid PTH assay and its clinical performance in a series of 200 patients.

Methods: PTH was measured with a modified immunochemiluminometric assay with a 7-min incubation time (QuiCk-IntraOperative™ Intact PTH assay). The rapid assay was compared with results in a central laboratory (immunoradiometric assay) in 44 EDTA-plasma specimens. The rapid assay was used intraoperatively in 200 consecutive cases with specimens analyzed before and 5–10 min after resection of the hypersecreting parathyroid gland(s).

Results: Intraassay imprecision was 12% at 28 ng/L and 11% at 278 ng/L. Regression analysis of results of the rapid PTH assay and the IRMA PTH assay in 44 parathyroidectomy patients yielded y = 1.26x − 12 ng/L, Sy|x = 26.3 ng/L, r = 0.984, and in 40 of 44 patients with values &lt;200 ng/L, y = 1.02x + 1.9, Sy|x = 13.9, r = 0.947. In the 195 cases using intraoperative PTH testing with complete results and defined clinical outcomes, the overall accuracy of the assay in predicting surgical success was 88% using the criterion of a 50% decrease at 5–10 min and 97% including the subset of patients with delayed decreases of PTH.

Conclusions: The rapid PTH assay had excellent analytical performance and excellent agreement with the PTH immunoradiometric assay and predicted the success of parathyroid surgery in this large series of consecutive patients.

One hundred consecutive minimally invasive parathyroid explorations

OBJECTIVE

To review the outcomes of 100 consecutive minimally invasive parathyroid explorations.

SUMMARY BACKGROUND DATA

Minimally invasive parathyroidectomy (MIP) has challenged the traditional approach of bilateral neck exploration for patients with primary hyperparathyroidism. Most patients with primary hyperparathyroidism have a single adenoma that when resected results in cure. It therefore appears logical to perform a directed approach to adenoma extirpation. MIP involves high-quality sestamibi images obtained with single photon emission computed tomography to localize enlarged parathyroid glands in three dimensions, limited exploration after surgeon-administered cervical block anesthesia, rapid intraoperative parathyroid hormone assay to confirm the adequacy of resection, and discharge within 1 to 3 hours of surgery.

METHODS

MIP was offered to 100 selected consecutive patients during an 18-month period beginning in March 1998.

RESULTS

Ninety-two cases were accomplished under cervical block anesthesia and 89 of these on an ambulatory basis. The cure rate was 100%, and there were no long-term complications. The mean hospital charge for MIP was less than 40% of that associated with traditional exploration.

CONCLUSIONS

Outpatient MIP appears to be the procedure of choice for most patients with primary hyperparathyroidism.

Minimally invasive parathyroidectomy: 50 consecutive cases

OBJECTIVE

To determine the effectiveness and outcomes of minimally invasive parathyroidectomy.

DESIGN

Prospective, non-randomised, non-blinded trial.

SETTING

Affiliated university teaching hospitals of the Northern Clinical School, University of Sydney, New South Wales, May 1998 to October 1999.

PATIENTS

50 consecutive patients who underwent minimally invasive parathyroidectomy for primary hyperparathyroidism, and 150 consecutive patients undergoing open parathyroidectomy over the same period.

RESULTS

Minimally invasive parathyroidectomy was successfully completed and resulted in cure (normocalcaemia) in 42 of 50 patients (84%). Seven patients (14%) required conversion to an open procedure, all of which also resulted in normocalcaemia, giving an overall cure rate of 98%. One patient had persistent hyperparathyroidism after minimally invasive parathyroidectomy which was cured at subsequent open reoperation. Three patients had a temporary recurrent laryngeal nerve palsy. Open parathyroidectomy was successful in 147 of 150 patients (98%) at initial operation; one patient had a temporary recurrent laryngeal nerve palsy. Intraoperative measurement of parathyroid hormone levels by a quick technique in 23 of the patients (13 having minimally invasive and 10 open procedures) correctly identified the presence of multiple-gland disease.

CONCLUSION

Minimally invasive parathyroidectomy is a feasible procedure, although there are concerns about the complication rate.

Retrospective analysis of sequential changes in serum intact parathyroid hormone levels during conventional parathyroid exploration

BACKGROUND

The purpose of this study was to assess sequential changes in serum parathyroid hormone (PTH) levels during conventional parathyroidectomy.

METHODS

Sera were collected before and 10 minutes after resection of each parathyroid tumor from 112 consecutive patients and assayed postoperatively within 48 hours for PTH.

RESULTS

PTH reductions corroborated cures for 94 of 112 cases (84%), including 70 of 71 patients with solitary adenomas (SAs). However, there were 15 false positives (13%), in which PTH decreased more than 50% within 10 minutes of resection of 1 parathyroid tumor while additional parathyroid tumors remained in situ (1 of 71 SAs, 4 of 6 double adenomas, 7 of 15 primary hyperplasias, and 3 of 17 tertiary hyperplasias). There were 3 false negatives (3%), with PTH unchanged, even though postoperative PTH and calcium values confirmed cure (1 SA, 1 primary hyperplasia, and 1 tertiary hyperplasia). There were only 2 of 112 failed explorations (1.8%), which would not have been avoided by PTH monitoring because both subsequently were found to have mediastinal parathyroid adenomas.

CONCLUSIONS

We conclude that intraoperative PTH changes corroborated outcome in SA but may under-estimate the extent of resection required in parathyroid hyperplasia.