Surgical and calcium outcomes in 427 patients treated prospectively in an image-guided and intraoperative PTH (IOPTH) supplemented protocol for primary hyperparathyroidism: outcomes and opportunities

The role of Rapid Intraoperative Parathyroid Hormone (ioPTH) assay in determining outcome of parathyroidectomy in primary hyperparathyroidism: A systematic review and meta-analysis

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder. In the last few decades, the introduction of Rapid Intraoperative Parathyroid Hormone (ioPTH) monitoring has allowed to ensurance of the excision of all hyperfunctioning parathyroid tissues, reducing the risks of persistent and recurrent PHPT. However, the use of ioPTH is still debated among endocrine surgeons.

MATERIAL AND METHODS

The objective of this systematic review and meta-analysis was to assess if ioPTH monitoring is able to reduce the incidence of persistent or recurrent PHPT. A systematic literature search was performed using PubMed, Scopus, ISI-Web of Science and Cochrane Library Database. Prospective and retrospective studies addressing the efficacy of ioPTH monitoring were included in the systematic review and meta-analysis. The random-effects model was assumed to account for different sources of variation among studies. The overall effect size was computed through the inverse variance method. Heterogeneity across studies, possible outlier studies, and publication bias were evaluated.

RESULTS

A total of 28 studies with 13,323 patients were included in the quantitative analysis. The incidence of operative failure was 3.2% in the case group and 5.8% in the control group. After excluding three outlier studies, the quantitative analysis revealed that ioPTH reduced significantly the incidence of postoperative persistent or recurrent PHPT. (Risk Difference = -0.02; CI = -0.03, -0.01; p < 0.001). There was no evidence of heterogeneity among the studies (Q = 19.92, p = 0.70; I² = 0%). The analysis of several continuous moderators revealed that the effectiveness of ioPTH was larger in studies with lower preoperative serum calcium values and higher incidences of multiple gland disease.

CONCLUSION

ioPTH monitoring is effective in reducing the incidence of persistent and recurrent PHPT. Its routine use should be suggested in the next guidelines regarding management of PHPT.

Routine bilateral neck exploration and four-gland dissection remains unnecessary in modern parathyroid surgery

Objective

Recent advances in preoperative imaging techniques and intraoperative parathyroid hormone (ioPTH) assays have made single-gland, minimally invasive parathyroidectomy (MIP) the preferred treatment option for most patients with primary hyperparathyroidism (pHPT). Despite this evolution, a recommendation for bilateral neck exploration (BNE) with four-gland dissection in all patients has recently been advocated by a parathyroid surgical group. The current study compares the long-term outcomes of MIP with those of conventional BNE with four-gland dissection in patients with pHPT.

Methods

In order to objectively assess a recommendation in the literature that universal BNE with four-gland dissection is advisable, all patients undergoing an initial MIP with ioPTH assessment for pHPT in a tertiary endocrine practice during a 10-year period were reviewed. The cure rates from this procedure were compared with published results of conventional BNE with four-gland dissection.

Results

Of the 561 patients undergoing parathyroidectomy during the study period, 337 had initial surgery for pHPT; 282 of these patients met inclusion criteria and 212 had sufficient follow-up data available. A single adenoma was identified in 87.3% of cases. Preoperative imaging studies were co-localizing in 148 (69.8%), and 127 (85.8%) of these patients with co-localizing imaging required only single-gland surgery. Imaging studies did not co-localize in 49 patients, yet 32 (65.3%) of these patients were still cured with unilateral surgery. The cure rate for patients undergoing MIP was 98.6%, with a long-term recurrence rate of <2%.

Conclusion

When coupled with the ioPTH assay, patients with at least one preoperative localizing study can undergo MIP and anticipate a cure rate of 99%, which is as good as or better than the published rates for conventional BNE with four-gland dissection. With unilateral surgery, the risks of permanent hypoparathyroidism and airway obstruction from bilateral vocal fold paralysis are completely eliminated. Therefore, despite recommendations to the contrary, most patients with pHPT should not have a planned four-gland exploration.

Level of Evidence

III or IV.

Outcomes of Parathyroidectomy in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-analysis

BACKGROUND

Parathyroidectomy is a definitive treatment for primary hyperparathyroidism. Patients contemplating this intervention will benefit from knowledge regarding the expected outcomes and potential risks of the currently available surgical options.

PURPOSE

To appraise and summarize the available evidence regarding benefits and harms of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE).

DATA SOURCES

A comprehensive search of multiple databases (MEDLINE, EMBASE, and Scopus) from each database's inception to September 2014 was performed.

STUDY SELECTION

Eligible studies evaluated patients with primary hyperparathyroidism undergoing MIP or BNE.

DATA EXTRACTION

Reviewers working independently and in duplicate extracted data and assessed the risk of bias.

DATA SYNTHESIS

We identified 82 observational studies and 6 randomized trials at moderate risk of bias. Most of them reported outcomes after MIP (n = 71). Using random-effects models to pool results across studies, the cure rate was 98 % (95 % CI 97-98 %, I (2) = 10 %) with BNE and 97 % (95 % CI 96-98 %, I (2) = 86 %) with MIP. Hypocalcemia occurred in 14 % (95 % CI 10-17 % I (2) = 93 %) of the BNE cases and in 2.3 % (95 % CI 1.6-3.1 %, I (2) = 87 %) with MIP (P < 0.001). There was a statistically significant lower risk of laryngeal nerve injury with MIP (0.3 %) than with BNE (0.9 %), but similar risk of infection (0.5 vs. 0.5 %) and mortality (0.1 vs. 0.5 %).

LIMITATIONS

The available evidence, mostly observational, is at moderate risk of bias, and limited by indirect comparisons and inconsistency for some outcomes (cure rate, hypocalcemia).

CONCLUSION

MIP and BNE are both effective surgical techniques for the treatment of primary hyperparathyroidism. The safety profile of MIP appears superior to BNE (lower rate of hypocalcemia and recurrent laryngeal nerve injury).

Outpatient Parathyroid Surgery: Ten-Year Experience: Is it Safe?

Outpatient parathyroid surgery is increasing in frequency especially for patients undergoing minimally invasive operations. From January 1, 2000 to December 31, 2009, 585 operations were performed on patients with untreated primary hyperparathyroidism. Outpatient operations were performed on 43 per cent (249/585), whereas 57 per cent (336/585) were admitted. Comorbidities were present in 63 per cent of outpatients and 72 per cent of inpatients, whereas systemic complications occurred in 0.8 per cent of outpatients and 7 per cent of inpatients. Ninety-four per cent of outpatients were minimally invasive although inpatient procedures were evenly divided. Local complications were low (8% and 6%) in both groups. Using zip codes to determine distance from home to hospital, no differences were noted. Readmission rates were low (< 0.5%) and the same in each group. Inpatients longer than 23 hours tended to be older with higher local and systemic complication rates. Over a decade, most patients undergoing same day parathyroid surgery had minimally invasive operations with lower comorbidities and lower systemic complications than inpatients. Minimally invasive and less complex nonminimally invasive operations can safely be performed on an outpatient basis with careful patient selection. Patient with more severe comorbidities and multiple comorbidities are less favorable candidates for outpatient surgery because of a higher risk of systemic complications.

Minimally Invasive Parathyroid Surgery, The Norman 20% Rule: Is It Valid?

The 20 per cent rule proposed by Norman established a guideline using radioactivity in the minimally invasive radioguided parathyroidectomy (MIRP) technique to localize and confirm removal of an abnormal parathyroid gland in patients with primary hyperparathyroidism. If radioactivity in the resected gland was at least 20 per cent of excision site/background radioactivity, the 20 per cent rule was satisfied. Patients meeting these criteria underwent unilateral MIRP without intraoperative parathyroid hormone assay or intraoperative frozen section. The study aim was to independently evaluate the 20 per cent rule in MIRP patients with primary hyperparathyroidism. Using the University of Louisville Parathyroid Database from January 1, 1999 to December 31, 2007, 216 MIRP patients with complete radioguided and postoperative management data were identified. The average percentage of ex vivo parathyroid gland radioactivity compared with excision site/background radioactivity was 107 per cent with a range from 14 to 388 per cent. For 99 per cent (196/198) radioactivity recorded from the excised gland was at least 20 per cent of radioactivity recorded from the excision site. Normocalcemia was documented in 98.5 per cent (195/198) at 12 month follow-up. Our data supports the 20 per cent rule in that in 99 per cent of MIRP patients the resected gland radioactivity was at least 20 per cent of excision site radioactivity allowing localization and confirmation of an overactive gland without intraoperative parathyroid hormone monitoring or tissue analysis.