Sonographic Features of Atypical and Initially Missed Parathyroid Adenomas: Lessons Learned From a Single-Center Cohort

CONTEXT

Awareness of typical and atypical ultrasonographic (US) features of parathyroid adenomas (PAs) is crucial since US is the most widely used first-line imaging modality.

OBJECTIVE

The purpose of this study was to describe the atypical features of PAs on US and other possible factors leading to a false negative examination in a large single-center cohort.

MATERIALS AND METHODS

The US records of 457 PAs in 445 patients with biochemically proven primary hyperparathyroidism (PHPT) were evaluated in a prospectively maintained database. Atypical size, composition, shape, echogenicity, location, and vascular pattern on US were noted. For patients who previously had at least one negative US examination in referring centers, the main possible reason was defined accordingly.

RESULTS

The study group included 359 female and 86 male patients with PHPT. Typical sonographic features were observed in 231 PAs (51%), whereas 226 (49%) had at least one atypical US feature. The most common atypical features were atypical size (29%), followed by atypical echogenicity (19%), shape (8%), location (7%), and composition (7%), respectively. There were 122 initially missed PAs in all groups. The most frequent main atypical US features leading to false negative examinations were atypical size (22.1%) and atypical location (18.8%). Inexperience was third most common reason (16.3%) for false negative US examinations.

CONCLUSIONS

Almost half of PAs have at least one atypical feature on US. Awareness of the high prevalence of atypical US features could increase the accuracy of US examination and potentially decrease demand for more expensive second-line imaging modalities.

Utility of 99mTc-Sestamibi Single-Photon Emission Computed Tomography (SPECT)/CT Single Imaging Strategy in the Preoperative Localization of Parathyroid Adenoma

Background Primary hyperparathyroidism is an endocrinopathy associated with dysregulated calcium homeostasis. The most common etiology is a parathyroid adenoma most definitely managed via a parathyroidectomy. The two main surgical approaches include a minimally invasive parathyroidectomy (MIP) and open four-gland exploration (4-GE). MIP is the preferred operative strategy since it is associated with less postoperative complications. Accurate preoperative imaging is essential in informing the optimal approach to surgery. MIP is only considered if adenoma is able to be localized precisely. The most commonly used imaging modality includes ultrasound and sestamibi single-photon emission computed tomography (SPECT)/CT, either as a single or combination strategy. Other options include MRI, PET, and 4D CT. There is no universally accepted preoperative imaging strategy. The literature is discordant and recommendations proposed by existing guidelines are incongruous. Objectives This study aimed to evaluate currently utilized preoperative parathyroid imaging modalities at our institution and correlate them with surgical and histological findings to determine the most efficient imaging strategy to detect adenomas for our patient cohort. This will ultimately guide the best surgical approach for patients receiving parathyroidectomies. Methods This is a retrospective observational study of all patients undergoing first-time surgery for biochemically proven primary hyperparathyroidism at our institution over the past five years. Multiple data points were collected including modality of preoperative disease localization, operation type, final histopathology, biochemical investigations, and cure rate. Patients were categorized into one of three groups based on the method of disease localization. Results A total of 244 patients had parathyroidectomies performed at our institution in the past five years from January 2018 to December 2022. Ninety-six percent (n=235) of all patients received dual imaging preoperatively with SPECT/CT and ultrasound performed on the same day and therefore included in this study. A total of 64.3% (n=151) underwent MIP. Eighty percent (n=188) of all histopathology revealed adenomas and 26.8% (n=63) of patients had adenoma localized on SPECT/CT only (sensitivity: 58.1%, specificity: 71%, and positive predictive value {PPV}: 85.7%). A total of 9.8% (n=23) had adenoma localized on ultrasound only (sensitivity: 15.6%, specificity: 73.3%, and PPV: 65.2%). A total of 45.1% (n=106) were dual localized on both SPECT/CT and ultrasound (sensitivity: 75.6%, specificity: 46.6%, and PPV: 84.9%). The cure rate was 91.5% in the dual-localized group, 86% in the dual-unlocalized group, and 96.5% when localized with SPECT/CT alone. Conclusion A dual-imaging modality with SPECT/CT and ultrasound should remain the first-line imaging strategy. This approach has higher sensitivity rates and poses no inherent patient or surgical-related risks. Patients with disease unlocalized on SPECT/CT alone had a positive predictive value, specificity, and likelihood ratio for adenoma detection comparable to dual-localized patients. Therefore, SPECT/CT alone is sufficient for directing MIP in the presence of a negative ultrasound.

Open Minimally Invasive Parathyroidectomy Versus Minimally Invasive Video-Assisted Parathyroidectomy: A Systematic Review and Meta-Analysis

Various minimally invasive techniques exist for surgical parathyroidectomy. The aim of this study was to conduct a meta-analysis comparing two popular minimally invasive techniques: minimally invasive video-assisted parathyroidectomy (MIVAP) and open minimally invasive parathyroidectomy (OMIP). An extensive search was conducted of online databases to identify all previous studies that had compared MIVAP and OMIP. The primary outcome measures considered were visual analog scale (VAS) score 24 hours postoperatively, conversion of operation (to open), failure rate and analgesic consumption. The data from these studies was extracted and compiled into a meta-analysis. The literature search yielded 104 studies of which four were included, enrolling 903 patients in this analysis. A significant difference was found regarding rates of conversion to open parathyroidectomy between the two groups, with the OMIP group demonstrating fewer conversions (MD = 3.52, CI = (2.04-6.08), P< 0.00001). No statistically significant differences were found between the two groups when comparing postoperative VAS scores at 24 hours (MD = -1.75, CI = (-9.8-6.3), P = 0.67), consumption of analgesia (OR = 0.49, CI = 0.07-3.54, P = 0.48) or failure rates (OR = 1.81, CI = 0.58-5.72, P = 0.31). OMIP was seen to require less need to convert to open parathyroidectomy with shorter operative times, while similar complication rates and scar lengths to MIVAP. More studies are required to evaluate the superior technique for parathyroidectomy.

A scoping review of approaches used for remote-access parathyroidectomy: A contemporary review of techniques, tools, pros and cons

After our coauthors described the first remote-access parathyroidectomy (RAP) series in 2000, several other approaches were developed. No systematic review has been performed to classify and evaluate RAP techniques. We performed a literature search using PubMed and Cochrane Library (CENTRAL). A total of 71 studies met our inclusion/exclusion criteria. RAP can be categorized into five approaches: (1) endoscopic and robotic axillary, (2) anterior chest, (3) transoral, (4) retroauricular, and (5) a combination of these approaches. The limited data in the literature suggest that the cure rates and safety of RAP are in no way inferior to those of open parathyroidectomy. Each approach has its advantages and disadvantages, and the recommendations for the selection of each approach are listed. The selection of approach methods might depend on the surgeon's experience and familiarity and the patient's preference and disease status.

Advances in the diagnosis and the management of primary hyperparathyroidism

The parathyroid glands, one of the last organs to be discovered, are responsible for maintaining calcium homeostasis, and they continue to present the clinician with diagnostic and management challenges that are reviewed herein. Primary hyperparathyroidism (PHPT) comprises the vast majority of pathology of the parathyroid glands. The classic variant, presenting with elevated calcium and parathyroid hormone levels, has been studied extensively, but the current body of literature has added to our understanding of normocalcemic and normohormonal variants of PHPT, as well as syndromic forms of PHPT. All variants can lead to bone loss, kidney stones, declining renal function, and a variety of neurocognitive, gastrointestinal, and musculoskeletal complaints, although the majority of PHPT today is asymptomatic. Surgery remains the definitive treatment for PHPT, and advances in screening, evolving indications for surgery, new imaging modalities, and improvements in intra-operative methods have greatly changed the landscape. Surgery continues to produce excellent results in the hands of an experienced parathyroid surgeon. For those patients who are not candidates for surgery, therapeutic advances in medical management allow for improved control of the hypercalcemic state. Parathyroid cancer is extremely rare; the diagnosis is often made intra-operatively or on final pathology, and recurrence is common. The mainstay of treatment is normalization of serum calcium via surgery and medical adjuncts.

Individualised Timing of Radio-Guided Parathyroidectomy Using Multi-Phase SPECT/CT Increases In Vivo Sensitivity and Accuracy and Reduces Operating Time: A Randomised Clinical Trial

Background: Minimally invasive parathyroidectomy is the preferred treatment for primary hyperparathyroidism. Despite relatively accurate preoperative information, minimally invasive parathyroidectomy can be challenging, especially in the case of small and ectopic adenomas. Radio guidance aids in both in vivo identification and ex vivo confirmation of adenoma. In vivo accuracy is currently not satisfactory. The present study evaluated whether a beneficial effect (increased sensitivity, specificity, accuracy) is obtained with individualised timing of minimally invasive radio-guided parathyroidectomy (MIRGP) using preoperative multi-phase 99mTc-MIBI single photon emission computed tomography (SPECT)/computed tomography (CT). Methods: This randomised clinical trial was conducted from May 2016 to January 2020 in a tertiary referral hospital. Adult patients with primary hyperparathyroidism sent for 99mTc-MIBI SPECT/CT were included consecutively and randomly assigned to conventional (dual-phase) SPECT/CT and conventional MIRGP (group I) or multi-phase SPECT/CT and individualised MIRGP (group II). One hundred of 106 eligible patients were included, and 83 patients underwent complete intervention. Results: A total of 47 patients in group I and 35 patients in group II were analysed. Group II had a shorter operating time (p = 0.003). The in vivo sensitivity and accuracy of radio guidance was 85.1% in group I and 100% in group II (p = 0.046), and 90.4% in group I and 100% in group II (p = 0.021), respectively. We found no difference in the in vivo specificity and ex vivo parameters between groups. Conclusion: Individualised timing increased the in vivo sensitivity and accuracy of radio guidance and reduced operating time, as some parathyroid adenomas rapidly wash out the radionuclide.

Original Preoperative Localization Technique of Parathyroid Adenomas by 3-Dimensional Virtual Neck Exploration

Objective. Preoperative imaging in primary hyperparathyroidism (PHPT) is essential for planning of parathyroidectomy-particularly for selection of a minimally invasive approach. The objective of this cohort study was to evaluate the diagnostic precision of 3D virtual neck exploration (3D-VNE), to evaluate its impact on choice of surgical approach, and to document the correlation with long-term outcomes. Methods. 235 consecutive patients with PHPT were studied (January 2014 to December 2018), with 6-month follow-up. 220 patients had a preoperative computed tomography (CT), 172 of these had a 3D-VNE based on the CT, and 226 patients had a Tc-99m sestamibi scan. Results. Sensitivity of exact, per gland, adenoma localization was 57.09% (95% CI: 50.85-63.10%) for nonspecialized radiologist interpretation of CT scan, 58.17% (95% CI: 51.99-64.10%) for Tc-99m sestamibi scan, and 90.21% (95% CI: 85.21-93.64%) for 3D-VNE, and thereby favoring 3D-VNE compared to CT scan alone (OR 34.5, 95% CI: 9.19-290.56%, P < 2.2 × 10^-16) and to Tc-99m sestamibi scan (OR 16.25, 95% CI: 6.05-61.42%, P = 3.1 × 10^-15). Specificity was 87.38% for CT scan, 86.36% for 3D-VNE, and 90% for Tc-99m sestamibi scan (P > .05). The cure rate was 100%. The long-term recurrence rate (RR) was 2.978%. The RR was 1.324% in the video-assisted parathyroidectomy group of 151 patients and 5.952% in the group of 84 patients with cervicotomy (P = .0459). Conclusion. CT-based 3D-VNE proved to be the most accurate localizing study in PHPT and aided in selecting patients for targeted minimally invasive parathyroidectomy, which was associated with the lower recurrence rate. 3D-VNE could be proposed as a first-line imaging study in patients with PHPT.

Revisiting a Case of Parathyroid Adenoma With Bilateral Staghorn Calculus

Parathyroid gland adenoma is responsible for approximately 80%-85% cases of primary hyperparathyroidism. Although not much is diagnostic on clinical examination, the blood investigations of the patients reveal raised serum calcium and serum parathyroid hormone levels. We present a case of chronic kidney disease with bilateral staghorn calculi and a right parathyroid adenoma localized on ultrasonography. Parathyroid adenoma was surgically excised by minimally invasive parathyroidectomy.

Intraoperative Adjunct Methods for Localization in Primary Hyperparathyroidism

Primary hyperparathyroidism (pHPT) is a frequently seen endocrine disease, and its main treatment is surgery. In the majority of pHPT, the disease involves only a single gland, and the majority of the pathological glands can be determined by preoperative localization methods.In addition to preoperative localization studies in parathyroidectomy, the use of adjunct methods to improve intraoperative localization in order to increase success of surgery is becoming widespread. These methods include different approaches, mainly intraoperative parathyroid hormone (PTH) measurement, followed by intraoperative gamma probe application, intraoperative ultrasonography, parathyroid imaging with methylene blue, and frozen section examination. Recently, especially promising new imaging methods have been described in the literature with various optical technologies to increase the localization of the parathyroid glands and to evaluate their viability. These methods include parathyroid imaging with autofluorescence, indocyanine green imaging with autofluorescence, autofluorescence imaging with methylene blue, autofluorescence imaging with 5-aminolevulinic acid, optical coherence tomography, laser speckle contrast imaging, dynamic optical contrast imaging, and Raman spectroscopy. Currently, minimally invasive parathyroidectomy has become the standard treatment for selected pHPT patients with the aid of preoperative imaging and intraoperative auxiliary methods . The aim of the present study was to evaluate the routinely used new promising intraoperative adjunct methods in pHPT.

Surgical options in treating patients with primary hyperparathyroidism

Background

Primary hyperparathyroidism is the third most common endocrine disorder for which surgical procedure called parathyroidectomy is the most effective treatment. Since the early 20^th century, parathyroid surgery has improved extensively. With the advances in preoperative imaging and with understanding the causes of disease, new and minimally invasive surgical approaches overrode the standard bilateral exploratory operations. Directed parathyroidectomy is currently the standard technique for treatment of primary hyperparathyroidism worldwide.

Conclusions

Surgery is the only definitive treatment of primary hyperparathyroidism. The most appropriate type of surgical procedure depends on the number and localization of the hyperactive parathyroid glands, availability of modern imaging techniques, limitation of each type of procedure and expertise.

Surgery versus Imaging in Non-Localizing Primary Hyperparathyroidism: A Cost-Effectiveness Model

OBJECTIVE

To determine whether advanced imaging is cost-effective compared to primary bilateral neck exploration in the management of non-localizing primary hyperparathyroidism.

STUDY DESIGN

Cost-effectiveness analysis.

METHODS

Cost-effectiveness analysis based on decision tree model and available Medicare financial data using data from 347 consecutive patients having parathyroidectomy for primary hyperparathyroidism with either 1) positive, concordant ultrasound and sestamibi or 2) negative sestamibi and negative ultrasound.

RESULTS

Bilateral neck exploration (BNE) costs $9578 and has a success rate of 97.3%. Single photon emission computed tomography (SPECT) + minimally invasive parathyroidectomy (MIP) was modeled to have a total cost of $8197 with a success rate of 98.6%. SPECT/computed tomography (CT) + MIP was modeled to have a total cost of $8271 and a 98.9% success rate. Four-dimensional (4D)-CT + MIP was modeled to cost $8146 with a success rate of 99%. Incremental cost-effectiveness ratios (IECR) (as compared to BNE) were -536.1, -605.5, and -701.6 ($/percent cure rate) for SPECT, SPECT/CT, and 4D-CT respectively. One-way sensitivity analyses demonstrate the change in IECR and cut-off points (IECR = 0) for four major variables.

CONCLUSIONS

In patients with non-localizing primary hyperparathyroidism, advanced imaging is associated with cost-savings compared to routine bilateral neck exploration. Increased cost-savings were predicted with increased imaging accuracy and decreased imaging costs. Increasing time for BNE or decreasing time for MIP were associated with increased cost savings.

LEVEL OF EVIDENCE

III Laryngoscope, 2020.

Minimally invasive parathyroidectomy using intraoperative ultrasonographic localization for primary hyperparathyroidism in pregnancy: report of two cases

Primary hyperparathyroidism (pHPT) in pregnancy is a rare entity associated with increased maternal and fetal mortality and morbidity. Diagnosis of pHPT is challenging in pregnancy. Approximately 80% of the cases are asymptomatic, while the most common symptoms are nausea, vomiting, polyuria, polydypsia, and cloudy vision in symptomatic patients. Since the most common cause of pHPT in pregnancy is adenoma, such in the general population, focused anterior or lateral approach is recommended due to shorter operation time, less risk for the fetus, and lower complication risk. Performing intraoperative ultrasonography to do the incision just over the adenoma provides quicker access to the adenoma and intraoperative parathormone assay confirms the surgical cure. Laryngeal mask anesthesia causes lesser sore throat, laryngospasm, coughing, and rapid recovery as compared to endotracheal intubation anesthesia. This study aimed to present the management of two pregnant patients diagnosed with pHPT and who underwent minimally invasive parathyroidectomy under intraoperative ultrasonography and laryngeal mask anesthesia at the second trimester of gestation. To the best of our knowledge, parathyroidectomy under laryngeal mask anesthesia in pregnancy has never been described before.

Focused Parathyroidectomy Under Local Anesthesia - A Feasibility Study

PURPOSE

We conducted this study to evaluate the feasibility, patient satisfaction, and cost of performing focused parathyroidectomy under local anesthesia (LA) and mild sedation, administered and monitored by a surgeon.

MATERIALS AND METHODS

This was a prospective observational study of 30 patients with primary hyperparathyroidism (PHPT) undergoing a focused parathyroidectomy under LA and mild sedation at a single institution. The clinical features, gland weight, operating time, procedure time, postoperative pain scores, overall patient satisfaction, postoperative nausea and vomiting, analgesic requirements, complications, cost, and cure rates were documented. Data were analyzed using SPSS software version 17.0.

RESULTS

In two patients (6.7%), the procedure had to be completed under general anesthesia (GA). Postoperative temporary hypocalcemia was witnessed in 14 of 30 (46.7%), but only 1 required intravenous calcium infusion. About 21 of 30 (75%) were completely satisfied with LA, whereas 25 of 30 (89%) were completely satisfied with surgical procedure. Furthermore, all patients were keen to recommend this procedure under LA to their friends and family. Comparing the cost between performing the procedure under LA with that under GA, a significant difference was witnessed (P = 0.001). Among the 26 patients reviewed at 6 months, all had a normal serum calcium and parathyroid hormone levels indicating 100% cure rate.

CONCLUSION

Performing focused parathyroidectomy under LA is feasible; additionally, this method can significantly reduce the cost of the procedure (P = 0.001).

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.

A rural perspective on minimally invasive parathyroidectomy: optimal preoperative imaging and patient outcomes

BACKGROUND

Our retrospective review of prospectively collected data evaluated the efficacy of minimally invasive parathyroidectomy (MIP) and compared preoperative imaging modalities in a rural referral centre.

METHODS

Patients with a diagnosis of primary hyperparathyroidism underwent surgeon-performed ultrasound (SUS) and technetium-99 m sestamibi (MIBI). Radiologist-performed ultrasound (RUS) was sought when the diagnosis remained in doubt. Four-dimensional computed tomography (4DCT) first replaced RUS in mid-2014, then MIBI as a frontline modality in 2015. MIP was conducted if possible and bilateral neck exploration (BNE) when localization remained doubtful. Treatment was evaluated by histopathology and serum parathyroid hormone and calcium levels at 6 weeks.

RESULTS

A total of 122 of 165 (73.9%) glands were removed by MIP and 43 of 165 (26.1%) by BNE. Of 15 cases with non-localizing preoperative investigations, one patient had a negative BNE. A total of 160 of 165 (97.0%) patients underwent a successful operation, with five (3.0%) suffering persistent post-operative hypercalcaemia. SUS had a sensitivity of 79.4% (131/165) and a positive predictive value (PPV) of 97.0% (131/135). MIBI had a sensitivity of 60.0% (81/135) and a PPV of 95.3% (81/85). RUS produced a sensitivity of 65.5% (76/116) and PPV of 98.7% (76/77). When used as a second-line modality, 4DCT had a sensitivity of 76.9% (10/13) and PPV of 100%. The sensitivity and PPV were 85.7% (18/21) and 94.7% (18/19) after 4DCT's promotion to first-line use.

CONCLUSION

MIP can be safely performed in rural centres of adequate volume. We recommend that operations be guided by SUS with routine use of an adjunctive modality. Our study has seen 4DCT replace MIBI in this regard.

[The minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism]

AIM

To study feasibility, effectiveness and safety of minimally invasive video-assisted parathyroidectomy in patients with primary hyperparathyroidism; to define the advantages and disadvantages of this technique compared with conventional open surgery.

MATERIAL AND METHODS

The study includes the results of 33 minimally invasive video-assisted parathyroidectomies performed in patients with primary hyperparathyroidism. The control group included 36 patients who underwent conventional open surgery.

RESULTS

There were significantly increased time of surgery in the main group (41.2±12.7 min vs. 28.4±10.9 min, p<0.05), decreased need for postoperative analgesia (1,2±0.3 vs. 1.9±0.5 days, p<0.05) and significantly longer postoperative scar (1.8±0.2 vs. 6.2±0.5 cm, p<0.01). Incidence of complications was similar in both groups (6.1% vs. 8.3%, p>0.05).

CONCLUSION

Minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism is feasible, safe and effective intervention that improves early postoperative course and cosmetic outcomes.

Minimally invasive parathyroidectomy without using intraoperative parathyroid hormone monitoring or gamma probe

OBJECTIVE

Minimal invasive parathyroidectomy (MIP) is a common surgical technique for the treatment of primary hyperparathyroidism (PHPT) and is usually done in conjunction with positive imaging techniques. We aimed to assess the results of this technique, performed without the use of intraoperative tests, in cases with PHPT caused by a single parathyroid adenoma.

MATERIAL AND METHODS

The data for patients who were diagnosed with PHPT were assessed retrospectively. Only those who had undergone a parathyroid adenoma localization study with ultrasonography (US) and parathyroid scintigraphy (PS) before the surgery, along with those patients for whom the MIP technique was routinely performed with frozen pathology, were included.

RESULTS

The study group was made up of 65 patients who had undergone the MIP technique. The mean age of the patients was 56±14 (20-81), with most being females [M/F: 19 (29.2%)/46 (70.8%)]. The mean calcium values before the operation were 11.24±1.26 mg/dL (8-15.5) (normal range: 8.4-10.2), and the parathyroid hormone (PTH) values were 388 pg/mL (249-707.75). These same values, measured 24 hours after the operation, were determined as 9.04±1.04 mg/dL (6.8-13.9) and 27 pg/mL (6-86), respectively. The follow-up period for the patients was an average of 26.6±9.4 (3-76) months, and only 3 (4.6%) cases of persistent hyperparathyroidism were detected within this period.

CONCLUSION

Our success rate with MIP in PHPT cases was determined to be 95.4%; therefore, this technique may be applied with a high success rate without any assistance from intraoperative tests, such as rapid serum PTH (rPTH) assays or gamma probes, in the presence of localization results of PS and US.

A retrospective case-controlled study of video-assisted versus open minimally invasive parathyroidectomy

INTRODUCTION

Minimally invasive parathyroidectomy (MIP) with intraoperative parathyroid hormone assay (IOPTH) has successfully replaced conventional neck exploration in most patients with primary hyperparathyroidism (pHPT) and preoperatively localized parathyroid adenoma.

AIM

To compare outcomes of video-assisted MIP (MIVAP) to open MIP (OMIP).

MATERIAL AND METHODS

A retrospective case-controlled study of 455 patients with sporadic pHPT undergoing MIP with IOPTH at our institution in 2003-2012 was undertaken. The primary outcome measure was postoperative pain. Secondary outcome measures were: duration of surgery, recurrent laryngeal nerve (RLN) identification rate, conversion rate, length of hospital stay, cure rate, patients' satisfaction with cosmetic outcome, morbidity, costs, and diagnostic accuracy of IOPTH.

RESULTS

Of 455 patients with pHPT and a solitary parathyroid adenoma on preoperative imaging, 151 underwent MIVAP and 304 had OMIP. The following outcomes were favourable for MIVAP vs. OMIP: lower pain intensity during 24 h postoperatively (p < 0.001), lower analgesia request rate (p < 0.001), lower analgesics consumption (p < 0.001), higher recurrent laryngeal nerve identification rate (p < 0.001), shorter scar length (p < 0.001), and better cosmetic satisfaction at 1 month (p = 0.013) and at 6 months (p = 0.024) after surgery. However, MIVAP vs. OMIP had longer duration of surgery (p < 0.001), and was more expensive (p < 0.001). No differences were noted in the conversion rate, length of hospital stay, and morbidity.

CONCLUSIONS

Both MIVAP and OMIP approaches were equally safe and effective. However, the outcomes of MIVAP operations were superior to OMIP in terms of lesser postoperative pain, lower analgesics consumption, and better cosmetic satisfaction resulting from a smaller scar.

Clinical impact of SPECT-CT in the diagnosis and surgical management of hyper-parathyroidism

Hyper-functioning parathyroid glands with autonomous overproduction of PTH is the most frequent cause of hypercalcemia in outpatient populations with primary hyper-parathyroidism. It is generally caused by a solitary adenoma in 80%-90% of patients. Despite the various methodologies that are available for preoperative localization of parathyroid lesions, there is still no certain preoperative imaging algorithm to guide a surgical approach prior to the management of primary hyper-parathyroidism (P-HPT). Minimally invasive surgery has replaced the traditional bilateral neck exploration (BNE) as the initial approach in parathyroidectomy at many referral hospitals worldwide. In our study, we investigated diagnostic contributions of SPECT-CT combined with conventional planar scintigraphy in the detection of hyper-functioning parathyroid gland localization, since planar imaging has limitations. We also evaluated the efficacy of preoperative USG in adding to initial diagnostic imaging algorithms to localize a parathyroid adenoma.

METHODS

A total of 256 consecutive surgically naive patients with hyper-parathyroidism diagnosis were included in the following preoperative localization study. The study consisted of 256 consecutive patients with HPT, with a selected 154 patients who had neck surgery with definitive histology reports. All patients had 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) double-phase scintigraphy. The SPECT-CT procedure, combined with standard 99mTc-MIBI planar parathyroid scintigraphy with a pinhole and parallel-hole collimator to evaluate whether the SPECT-CT procedure was able to provide additional information in the localization of the pathology, caused hyper-parathyroidism in both P-HPT and S-HPT.

RESULTS

In the 154 P-HPT patients, 168 lesions (142 adenomas including 2 intrathyroidal and 2 double adenoma, 2 carcinoma, and 22 hyperplastic glands (four patients had MEN I, each with four hyperplastic glands)), were found at surgery. SPECT-CT detected more lesions than planar imaging in P-HPT (97.8% vs. 87.6%). SPECT-CT detected all adenomas and increased sensitivity, particularly in small lesions. Regardless of their size, the number of detected hyperplastic glands by SPECT-CT was remarkably higher than planar imaging.

Intraoperative adjuncts for parathyroid surgery

In recent years, parathyroid surgery has evolved from traditional bilateral neck exploration to minimal invasive parathyroidectomy. This trend became possible due to preoperative localization imaging that guides the surgeon in the search for a parathyroid adenoma. Intraoperative adjuncts are complementary to preoperative localization and assist in localizing parathyroid glands, confirming parathyroid tissue and establishing a cure. Institutions and surgeons utilize different intraoperative adjuncts in different protocols with varying results. The purpose of this article is to review the available intraoperative adjuncts to parathyroid surgery and critically evaluate their utility, accuracy and their added value to the surgeon.