Prevention and management of complications in parathyroid surgery

A contemporary analysis of the pre- and intraoperative recognition of multigland parathyroid disease

BACKGROUND

Despite advances in biochemical and radiological identification of parathyroid gland enlargement, primary hyperparathyroidism (PHPT) due to sporadic multigland parathyroid disease (MGPD) remains a perioperative diagnostic dilemma. Failure to recognise MGPD pre- or intraoperatively may negatively impact surgical cure rates and result in persistent PHPT and ongoing patient morbidity.

METHODS

We have conducted a comprehensive review of published literature in attempt to determine factors that could aid in reliably diagnosing sporadic MGPD pre- or intraoperatively. We discuss preoperative clinical features and examine pre- and intraoperative biochemical and imaging findings concentrating on those areas that give practicing surgeons and the wider multi-disciplinary endocrine team indications that a patient has MGDP. This could alter surgical strategy.

CONCLUSION

Biochemistry can provide diagnosis of PHPT but cannot reliably discriminate parathyroid pathology. Histopathology can aid diagnosis between MGPD and adenoma, but histological appearance can overlap. Multiple negative imaging modalities indicate that MGPD may be more likely than a single parathyroid adenoma, but the gold standard for diagnosis is still intraoperative identification during BNE. MGPD remains a difficult disease to both diagnose and treat.

Phenotypes of primary hyperparathyroidism: Does parathyroidectomy improve clinical outcomes for all?

BACKGROUND

Primary hyperparathyroidism consists of 3 biochemical phenotypes: classic, normocalcemic, and normohormonal primary hyperparathyroidism. The clinical outcomes of patients with normocalcemic primary hyperparathyroidism and normohormonal primary hyperparathyroidism are not well described.

METHOD

A retrospective review of patients who underwent parathyroidectomy at a single institution was performed. A logistical regression analysis of postoperative nephrolithiasis and highest percentage change in dual-energy x-ray absorptiometry scan comparison using Kruskal-Wallis test and Cox proportional hazard analysis of recurrence-free survival were performed.

RESULTS

A total of 421 patients were included (340 classic, 39 normocalcemic primary hyperparathyroidism, 42 normohormonal primary hyperparathyroidism). Median follow-up was 8.8 months (range 0-126). Higher rates of multigland disease were seen in normocalcemic primary hyperparathyroidism (64.1%) and normohormonal primary hyperparathyroidism (56.1%) compared to the classic (25.8%), P < .001. There were no differences in postoperative complications. The largest percentage increases in bone mineral density at the first postoperative dual-energy x-ray absorptiometry scan were higher for classic (mean ± SD, 6.4 ± 9.1) and normocalcemic primary hyperparathyroidism (4.8 ± 11.9) compared to normohormonal primary hyperparathyroidism, which remained stable (0.2 ± 14.2). Normocalcemic primary hyperparathyroidism were more likely to experience nephrolithiasis postoperatively, 6/13 (46.2%) compared to 11/68 (16.2%) classic, and 2/13 (15.4%) normohormonal primary hyperparathyroidism, P = .0429. Normocalcemic primary hyperparathyroidism was the only univariate predictor of postoperative nephrolithiasis recurrence (odds ratio [95% confidence interval] 4.44 [1.25-15.77], P = .029). Normocalcemic primary hyperparathyroidism was significantly associated with persistent disease with 6/32 (18.8%) compared to 1/36 (2.8%) and 3/252 (1.2%) in normohormonal primary hyperparathyroidism and classic (P < .001).

CONCLUSION

Three phenotypes of primary hyperparathyroidism are distinct clinical entities. Normocalcemic primary hyperparathyroidism had higher incidence of persistent disease and postoperative nephrolithiasis but demonstrated improvements in postoperative bone density. These data should inform preoperative discussions with patients with normocalcemic primary hyperparathyroidism and normohormonal primary hyperparathyroidism regarding postoperative expectations.

Minimally invasive parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IOPTH) and preoperative imaging versus bilateral neck exploration for primary hyperparathyroidism in adults

BACKGROUND

Bilateral neck exploration (BNE) is the traditional approach to sporadic primary hyperparathyroidism. With the availability of the preoperative imaging techniques and intraoperative parathyroid hormone assays, minimally invasive parathyroidectomy (MIP) is fast becoming the favoured surgical approach.

OBJECTIVES

To assess the effects of minimally invasive parathyroidectomy (MIP) guided by preoperative imaging and intraoperative parathyroid hormone monitoring versus bilateral neck exploration (BNE) for the surgical management of primary hyperparathyroidism.

SEARCH METHODS

We searched CENTRAL, MEDLINE, WHO ICTRP and ClinicalTrials.gov. The date of the last search of all databases was 21 October 2019. There were no language restrictions applied.

SELECTION CRITERIA

We included randomised controlled trials comparing MIP to BNE for the treatment of sporadic primary hyperparathyroidism in persons undergoing surgery for the first time.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Two review authors independently screened for inclusion, extracted data and carried out risk of bias assessment. The content expert senior author resolved conflicts. We assessed studies for overall certainty of the evidence using the GRADE instrument. We conducted meta-analyses using a random-effects model and performed statistical analyses according to the guidelines in the latest version of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We identified five eligible studies, all conducted in European university hospitals. They included 266 adults, 136 participants were randomised to MIP and 130 participants to BNE. Data were available for all participants post-surgery up to one year, with the exception of missing data for two participants in the MIP group and for one participant in the BNE group at one year. Nine participants in the MIP group and 11 participants in the BNE group had missing data at five years. No study had a low risk of bias in all risk of bias domains. The risk ratio (RR) for success rate (eucalcaemia) at six months in the MIP group compared to the BNE group was 0.98 (95% confidence interval (CI) 0.94 to 1.03; P = 0.43; 5 studies, 266 participants; very low-certainty evidence). A total of 132/136 (97.1%) participants in the MIP group compared with 129/130 (99.2%) participants in the BNE group were judged as operative success. At five years, the RR was 0.94 (95% CI 0.83 to 1.08; P = 0.38; 1 study, 77 participants; very low-certainty evidence). A total of 34/38 (89.5%) participants in the MIP group compared with 37/39 (94.9%) participants in the BNE group were judged as operative success. The RR for the total incidence of perioperative adverse events was 0.50, in favour of MIP (95% CI 0.33 to 0.76; P = 0.001; 5 studies, 236 participants; low-certainty evidence). Perioperative adverse events occurred in 23/136 (16.9%) participants in the MIP group compared with 44/130 (33.9%) participants in the BNE group. The 95% prediction interval ranged between 0.25 and 0.99. These adverse events included symptomatic hypocalcaemia, vocal cord palsy, bleeding, fever and infection. Fifteen of 104 (14.4%) participants experienced symptomatic hypocalcaemia in the MIP group compared with 26/98 (26.5%) participants in the BNE group. The RR for this event comparing MIP with BNE at two days was 0.54 (95% CI 0.32 to 0.92; P = 0.02; 4 studies, 202 participants). Statistical significance was lost in sensitivity analyses, with a 95% prediction interval ranging between 0.17 and 1.74. Five out of 133 (3.8%) participants in the MIP group experienced vocal cord paralysis compared with 2/128 (1.6%) participants in the BNE group. The RR for this event was 1.87 (95% CI 0.47 to 7.51; P = 0.38; 5 studies, 261 participants). The 95% prediction interval ranged between 0.20 and 17.87. The effect on all-cause mortality was not explicitly reported and could not be adequately assessed (very low-certainty evidence). There was no clear difference for health-related quality of life between the treatment groups in two studies, but studies did not report numerical data (very low-certainty evidence). There was a possible treatment benefit for MIP compared to BNE in terms of cosmetic satisfaction (very low-certainty evidence). The mean difference (MD) for duration of surgery comparing BNE with MIP was in favour of the MIP group (-18 minutes, 95% CI -31 to -6; P = 0.004; 3 studies, 171 participants; very low-certainty evidence). The 95% prediction interval ranged between -162 minutes and 126 minutes. The studies did not report length of hospital stay. Four studies reported intraoperative conversion rate from MIP to open procedure information. Out of 115 included participants, there were 24 incidences of conversion, amounting to a conversion rate of 20.8%.

AUTHORS' CONCLUSIONS

The success rates of MIP and BNE at six months were comparable. There were similar results at five years, but these were only based on one study. The incidence of perioperative symptomatic hypocalcaemia was lower in the MIP compared to the BNE group, whereas the incidence of vocal cord paralysis tended to be higher. Our systematic review did not provide clear evidence for the superiority of MIP over BNE. However, it was limited by low-certainty to very low-certainty evidence.

Volume-outcome relationship in parathyroid surgery

BACKGROUND

Since its first description, several studies have highlighted the role of the surgeon's experience in the outcome of parathyroid surgery, however, no uniform consensus exists regarding the minimum operative experience required for good surgical outcomes. This work aims to summarize the current data regarding the surgeon volume-outcome relationship for parathyroidectomy.

METHODS

An electronic literature review identified 85 publications, and after study selection 11 were included. An additional nine publications were added based on reference review and inclusion of publications not initially captured.

CONCLUSIONS

There are insufficient data to dogmatically conclude a minimum number of cases required to achieve optimal surgical results. However, extrapolation from the inclusive studies support the conclusions that higher operative volumes improve cure rates and decrease the rates of complications, recurrent disease, and perioperative costs. Endocrine Surgery fellowships or mentorships may help prepare the less experienced surgeon for successful outcomes. Although reticent to offer firm minimal volume requirements, we have made suggestions in this manuscript.

Morbidity in parathyroid surgery for renal disease is under reported: a comparison of outcomes with primary hyperparathyroidism

Introduction Parathyroidectomy is considered to be a safe procedure with low morbidity. However, while this is true for primary hyperparathyroidism, whether it applies to tertiary disease is not so well documented. The aim of this study was to assess the morbidity of surgery for tertiary hyperparathyroidism compared with primary disease and to establish whether there are predictive factors for poor outcomes. Methods Data for patients subjected to parathyroidectomy during the period 2007-2015 were retrospectively analysed from a prospectively collected database. Patient age, sex, American Society of Anesthesiologists (ASA) score, renal status, extent of operation and indications for surgery were examined. The complication and mortality rate were compared and independent predictors of outcome were examined. Results A total of 1079 patients were scheduled for a parathyroidectomy during the study period of whom 158 for renal related hyperparathyroidism (renal group) and 921 for primary disease (non-renal group). There was a significantly higher complication rate in the renal parathyroid group, including a higher mortality (1.3% vs 0.1%, P = 0.011), overall complication rate (7.0% vs 2.3%, P = 0.001), surgery related complication rate (4.4% vs 1.7%, P = 0.03) and systemic complication rate (2.5% vs 0.4%, P = 0.005). In patients with ASA score ≤ 2 reoperative surgery (OR 9.25, 95% confidence interval, CI 1.41-60.75), male sex (OR 4.12, 95% CI 1.46-11.63) and renal impairment were (OR 5.86, 95% CI 1.65-20.78) were predictors of worse outcomes. In patients with ASA score ≥3 renal impairment, in addition to other variables, were not predictors of complications. Conclusions Parathyroidectomy in renal-related disease is associated with a significantly higher risk of morbidity and mortality compared with primary hyperparathyroidism.

Association of Parathyroid Gland Biopsy Excision Technique With Ex Vivo Radiation Counts During Radioguided Parathyroid Surgery

Importance

Parathyroid biopsy represents a means for normal and hyperfunctional glands to be distinguished intraoperatively. However, no data exist to guide surgeons regarding how much of a parathyroid gland must be biopsied to satisfy the 20% rule.

Objective

To quantify the relative proportion of a hyperfunctional parathyroid gland that must be evaluated with the gamma probe to satisfy the 20% rule.

Design, Setting, and Participants

A retrospective review of surgical data for 24 consecutive patients (16 women, 18 men; mean [SD] age, 66.6 [10] years; range, 51-83 years) who underwent surgery for primary hyperparathyroidism between May and October, 2015, in a tertieary academic medical center.

Main Outcomes and Measures

Extirpated parathyroid glands were sectioned into parallel or pie-shaped biopsies and evaluated ex vivo with a gamma probe to determine what percentage of a hyperfunctional gland must be sampled to meet the Norman 20% rule. The hypothesis was formulated during data collection.

Results

In total, 253 ex vivo biopsy specimens were obtained from 33 surgically removed parathyroid glands. Parathyroid biopsies satisfied the 20% rule with an accuracy that depended on the relative proportion of the parent gland represented: half or more (96.6%; 95% CI, 91.7%-100.0%), a quarter to one-half (87.0%; 95% CI, 79.3%-94.7%), less than a quarter (63.6%; 95% CI, 54.5%-72.8%). When less than a quarter of the gland was removed, pie-shaped biopsies were more likely to satisfy the 20% rule compared with parallel biopsies of the same weight (78.4% vs 56.2%; absolute difference, 22.2%; 95% CI, 4.7%-39.7%).

Conclusions and Relevance

Unless half of a parathyroid gland is biopsied during radioguided parathyroidectomy, the 20% rule cannot reliably rule out the presence of a hyperfunctional parathyroid lesion. Pie-shaped biopsies originating from the center of the gland are associated with a lower rate of false-negative results compared with peripheral biopsies of similar size. Pie-shaped biopsies and biopsy of half or more of each nonexcised parathyroid gland for ex vivo counts may increase the risk of remnant devascularization and resultant hypoparathyroidism.

Primary Hyperparathyroidism: Effects on Bone Health

Primary hyperparathyroidism (PHPT) is the most common cause of chronic hypercalcemia. With the advent of routine calcium screening, the classic presentation of renal and osseous symptoms has been largely replaced with mild, asymptomatic disease. In hypercalcemia caused by PHPT, serum parathyroid hormone levels are either high, or inappropriately normal. A single-gland adenoma is responsible for 80% of PHPT cases. Less frequent causes include 4-gland hyperplasia and parathyroid carcinoma. Diminished bone mineral density and nephrolithiasis are the major current clinical sequelae. Parathyroidectomy is the only definitive treatment for PHPT, and in experienced hands, cure rates approach 98%.

Outcomes after subtotal parathyroidectomy for primary hyperparathyroidism due to hyperplasia: significance of whole vs. partial gland remnant

INTRODUCTION

Primary hyperparathyroidism (PHPT) due to multigland hyperplasia is managed by subtotal parathyroidectomy (sPTX), with a partial gland left in situ. However, smaller, hyperplastic glands may be encountered intraoperatively, and it is unclear if leaving an intact gland is an equivalent alternative. This study evaluates the rates of permanent hypoparathyroidism and cure of PHPT patients with four-gland hyperplasia that were left with either a whole gland remnant (WGR) or a partial gland remnant (PGR) after sPTX.

METHODS

We reviewed the outcomes of PHPT patients with hyperplasia who underwent sPTX at an academic institution. Surgeon intraoperative judgment determined remnant size (a WGR vs. a PGR).

RESULTS

Between 2002 and 2013, 172 patients underwent sPTX for PHPT. There were 108 patients (62.8%) who had a WGR. Another 64 patients (37.2%) had a PGR. Mean age was 60 ± 14 years. There were 82.6% female patients. Cases with positive family history for PHPT were more likely to have a PGR (12.5 vs. 3.7%; p = 0.03). Patients had similar preoperative and postoperative laboratories. Individuals with a PGR tended to have larger glands encountered by surgeons intraoperatively (525 ± 1,308 vs. 280 ± 341 mg; p = 0.02). One patient with a WGR developed permanent hypocalcemia. Overall, the cure rate was 97.1%. A mean of 29 ± 28.7 months follow-up revealed a recurrence rate of 5.2%. Disease persistence and recurrence rates were similar in patients.

CONCLUSION

PHPT due to hyperplasia is managed by sPTX, leaving WGR without increased rates of disease persistence/recurrence. Patients without family history for hyperparathyroidism and those with smaller glands may be the best candidates for this approach.

Endoscopic neck surgery

Endoscopic surgery in the neck was attempted in 1996 for performing parathyroidectomy. A similar surgical technique was used for performing thyroidectomy the following year. Most commonly reported endoscopic neck surgery studies in literature have been on thyroid and parathyroid glands. The approaches are divided into two types i.e., the total endoscopic approach using CO(2) insufflation and the video-assisted approach without CO(2) insufflation. The latter approach has been reported more often. The surgical access (port placements) may vary-the common sites are the neck, anterior chest wall, axilla, and periareolar region. The limiting factors are the size of the gland and malignancy. Few reports are available on endoscopic resection for early thyroid malignancy and cervical lymph node dissection. Endoscopic neck surgery has primarily evolved due to its cosmetic benefits and it has proved to be safe and feasible in suitable patients with thyroid and parathyroid pathologies. Application of this technique for approaching other cervical organs such as the submandibular gland and carotid artery are still in the early experimental phase.

Limitations of Tc99m-MIBI-SPECT imaging scans in persistent primary hyperparathyroidism

Background

In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83–100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands.

Method

We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery.

Results

In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy.

Conclusions

Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidism.

Immediate post-parathyroidectomy stridor resolved with intravenous calcium

A 73-year-old woman underwent an uncomplicated focused parathyroidectomy for an adenoma. Immediately after extubation she developed respiratory distress and her airway became compromised. No obvious cause could be found for the stridor and no response was obtained from nebulised adrenaline (norepinephrine). An intravenous bolus of calcium provided immediate but temporary relief. Lasting relief was obtained following the administration of an intravenous calcium infusion. Serology later confirmed a small decrease in calcium concentrations but at the time of the respiratory compromise the values were still within normal range.

Nuclear imaging and minimally invasive surgery in the management of hyperparathyroidism

Primary hyperparathyroidism is the most common cause of hypercalcemia, and the treatment is primarily surgical. Because of biochemical screening, more patients now present with asymptomatic primary hyperparathyroidism, and consensus guidelines have been developed for the treatment of these patients. There is now considerable interest in minimally invasive approaches to the treatment of hyperparathyroidism. Sestamibi scanning as a localizing study, used in combination with anatomic imaging and intraoperative rapid parathyroid hormone assays, has enabled focused surgical approaches. Patients with localizing studies that indicate a single parathyroid adenoma are candidates for such approaches, including unilateral neck exploration, minimally invasive single-gland exploration, or endoscopic exploration instead of the traditional approach of bilateral neck exploration. Nuclear imaging is also critical to the successful management of patients with persistent or recurrent hyperparathyroidism.