Identification Of Parathyroid Glands Research Articles

Increased Identification of Parathyroid Glands Using Autofluorescence Imaging during Thyroidectomy

Increased Identification of Parathyroid Glands Using Autofluorescence Imaging during Thyroidectomy

Intraoperative Real-Time Localization of Normal Parathyroid Glands With Autofluorescence Imaging.

This biomedical investigation is valuable for identification and localization of parathyroid glands during thyroidectomy, which can provide an intraoperative real-time visual guidance. The objective of the study was to investigate the feasibility of real-time autofluorescence imaging of the parathyroid glands without exogenous contrast dye for their localization and demonstration of relation to the background tissues. This research was undertaken at Kosin University Gospel Hospital. Sixteen normal parathyroid glands from eight patients with papillary thyroid carcinoma were enrolled. Photo images of the surgical field including the parathyroid and background tissues were taken with a digital camera, 780 nm light-emitting diode to excite the parathyroid, and infrared illuminator to visualize the entire neck. The area-averaged autofluorescence intensity of parathyroid over the area-averaged fluorescence intensity of background tissues was measured. The location of the parathyroid gland was verified with a single image. The area-averaged autofluorescence intensity of parathyroid over the area-averaged fluorescence intensity of background tissues for all parathyroid glands was higher than 1, with a minimum of 1.95 and a maximum of 5.20 (average 2.76, SD 0.79). By our technique, all 16 parathyroid glands were detected (positive predictive value of 100%), and the entire surgical field including the parathyroid and background tissues was visualized as well. The parathyroid glands that were exposed or even covered by connective tissues or blood vessels could be detected with strong emission. This method showed the precise localization of the parathyroid glands and demonstrated their relation to background tissue. We believe that this simple, nonexogenous dye technique of anatomical guidance can aid surgeons to preserve parathyroid glands during thyroidectomy.

Predictors and risk factors of hypoparathyroidism after total thyroidectomy

BackgroundThe aim of this study was to evaluate the risk factors for hypoparathyroidism after total thyroidectomy and to determine whether early postoperative serum levels of calcium and phosphorus could be used to predict its development. Materials and MethodsThe study group consisted of 1030 patients who had undergone total thyroidectomy at our institution between March 2008 and July 2014. The clinicopathologic characteristics, indications for the operation, and surgical details of normocalcemic and hypocalcemic patients were compared, and variations in serum calcium and phosphorus levels were measured every day after the operation. ResultsOf the 1030 patients, 291 (28.2%) were found to have transient hypocalcemia and 27 (2.6%) had permanent hypocalcemia. On univariate analysis, younger age (P = 0.001), female gender (P < 0.001), longer operative time (P = 0.009), extent of central neck dissection (CND) (P = 0.003), and malignancy (P = 0.005) were found to be significantly associated with transient hypocalcemia. On multivariate analysis, female gender (P = 0.001), extent of CND (P = 0.017), and the identification of parathyroid gland (PTG) tissue in permanent pathologic sections were significant factors. In addition, the occurrence of postoperative hypocalcemia was correlated with relative changes in serum calcium and phosphorus levels. Patients whose serum calcium levels decreased over 20% on postoperative day 2 were more likely to develop hypoparathyroidism, with 92% specificity. ConclusionFemale gender (P = 0.001), extent of CND (P = 0.014), and PTG in permanent pathologic sections (P = 0.035) were found to be significant factors affecting the development of hypocalcemia. Despite some study limitations, we suggest that the relative changes in the serum levels of calcium (20%) and of phosphorus (40%) on the second postoperative day may be reliable predictors of post-thyroidectomy hypoparathyroidism.

Incidence, Risk Factors, and Clinical Outcomes of Incidental Parathyroidectomy During Thyroid Surgery.

The reported rate of incidental parathyroidectomy (IP) during thyroid surgery is between 5.2 and 21.6%. Current literature reports wide discrepancy in incidence, risk factors, and outcomes. Thus study was designed to address definitively the topic of IP and identify associated risk factors and clinical outcomes with this multi-institutional study. This retrospective cohort study included 1767 total thyroidectomies that occurred between 1995 and 2014 at two academic centers. Pathologic reports were reviewed for the presence of unintentionally removed parathyroid glands. Demographics, potential risk factors, and postoperative calcium levels were compared with matched control group. Logistic regression, t tests, and Chi squared tests were used when appropriate. IP occurred in 286 (16.2%) of thyroidectomies. Risk factors for IP were: malignancy, neck dissection, and lymph node metastases (p=0.005, <0.001, and <0.001). Fifty-three (19.2%) of IPs were intrathyroidal. Those with IP were more likely to have postoperative biochemical (65.6 vs. 42.0%; p<0.001) and symptomatic (13.4 vs. 8.1%; p=0.044) hypocalcemia than controls. The number of parathyroids identified intraoperatively was inversely correlated with the number of parathyroid glands in the specimen (p<0.001). Our findings indicate that malignancy, lymph node dissection, and metastatic nodal disease are risk factors for IP. Patients with IP were more likely to have postoperative biochemical and symptomatic hypocalcemia than controls, showing that there is a physiologic consequence to IP. Additionally, intraoperative surgeon identification of parathyroid glands results in a lower incidence of IP, highlighting the importance of awareness of parathyroid anatomy during thyroid surgery.

Intraoperative Near-infrared Imaging for Parathyroid Gland Identification by Auto-fluorescence: A Feasibility Study.

Parathyroid glands (PGs) can be particularly hard to distinguish from surrounding tissue and thus can be damaged or removed during thyroidectomy. Postoperative hypoparathyroidism is the most common complication after thyroidectomy. Very recently, it has been found that the parathyroid tissue shows near-infrared (NIR) auto-fluorescence which could be used for intraoperative detection, without any use of contrast agents. The work described here presents a histological validation ex vivo of the NIR imaging procedure and evaluates intraoperative PG detection by NIR auto-fluorescence using for the first time to our knowledge a commercially available clinical NIR imaging device. Ex vivo study on resected operative specimens combined with a prospective in vivo study of consecutive patients who underwent total or partial thyroid, or parathyroid surgery at a comprehensive cancer center. During surgery, any tissue suspected to be a potential PG by the surgeon was imaged with the Fluobeam 800 (®) system. NIR imaging was compared to conventional histology (ex vivo) and/or visual identification by the surgeon (in vivo). We have validated NIR auto-fluorescence with an ex vivo study including 28 specimens. Sensitivity and specificity were 94.1 and 80%, respectively. Intraoperative NIR imaging was performed in 35 patients and 81 parathyroids were identified. In 80/81 cases, the fluorescence signal was subjectively obvious on real-time visualization. We determined that PG fluorescence is 2.93±1.59 times greater than thyroid fluorescence in vivo. Real-time NIR imaging based on parathyroid auto-fluorescence is fast, safe, and non-invasive and shows very encouraging results, for intraoperative parathyroid identification.

Cutting Edge in Thyroid Surgery: Autofluorescence of Parathyroid Glands

Identification of parathyroid glands may be challenging during thyroid and parathyroid surgery. Accidental resection of the glands may increase the morbidity of the surgery. The aim of this study was to evaluate accuracy in identification of autofluorescent parathyroid glands with the use of near infrared light in real time. Patients undergoing thyroid and parathyroid surgery between June and August 2015 were included in the study. During the procedure, the surgical field was exposed to near infrared laser light in order to analyze the intensity of the fluorescence of different tissues (parathyroid glands, thyroid glands, and background). Surgical images were recorded and analyzed. Twenty-eight patients were included in the study. Nineteen patients were women and 9 were men. Seven patients had primary hyperparathyroidism, 4 had hyperthyroidism, 3 had goiters, and 11 had thyroid cancer. Three patients had mixed pathologies, including 2 patients with thyroid cancer and primary hyperparathyroidism and 1 patient with goiter and primary hyperparathyroidism. Identification of autofluorescent parathyroid glands was achieved in all patients with near infrared light. The mean fluorescent intensity of parathyroid glands was 40.6 (±26.5), thyroid glands 31.8 (±22.3), and background 16.6 (±15.4). Parathyroid glands demonstrated statistically higher fluorescence intensity compared with the thyroid gland and background (p < 0.0014). No postoperative hypocalcemia or other complications related to the surgery were registered. Visualization of autofluorescent parathyroid glands with the use of near infrared light allows high rates of parathyroid gland identification and could be a safe, feasible, and noninvasive method for intraoperative identification of parathyroid glands in real time. Further clinical studies must be performed to determine the cost-effectiveness and clinical application of this method.

Challenges and Limitations of Narrow-Band Optical Imaging for Intra-Operative Parathyroid Identification

Background: Surgical resection of the parathyroid glands can be challenging due to poor visual contrast between the parathyroid and surrounding tissues. We hypothesized that narrow-band imaging (NBI) could enhance subtle differences in the colors of these tissues for improved visual contrast during parathyroid surgery. Methods: The diffuse optical reflectances of parathyroid, fat, muscle, and thyroid tissue were measured in vivo as a function of wavelength during six surgical procedures, using a fiber-optic probe and spectrophotometer. Analysis of these data led to three candidate NBI wavelength bands which exhibited the largest differences in reflectance between parathyroid and other tissue types. Color filters at these wavelength bands were attached to the surgeon’s loupes for qualitative visual assessment, and also to a digital camera for quantitative assessment of tissue contrast in seven additional surgeries. Results: Spectroscopic measurements showed that diffuse optical reflectance at green (515 - 565 nm), yellow (570 - 613 nm), and red (604 - 644 nm) wavelengths showed the greatest difference in intensity (appearing brighter or darker) between parathyroid and surrounding tissues. However, visual and digital NBI of the parathyroid using these wavebands generated measured intensities which were not significantly improved as compared to white light, providing only minimal contrast enhancement for the surgeon. Conclusions: Narrow-band color filters can be added to conventional loupes to selectively view the surgical field with light at specific wavelengths. When the parathyroid is viewed with filters chosen to maximize visual contrast between tissue types, there appears to be little benefit in contrast enhancement between tissues due to diminished overall brightness. J Curr Surg. 2016;6(1):14-20 doi: http://dx.doi.org/10.14740/jcs295w

Establishing the clinical utility of autofluorescence spectroscopy for parathyroid detection

The inability of surgeons to identify parathyroid glands accurately during cervical endocrine surgery hinders patients from achieving postoperative normocalcemia. An intrinsic, near-infrared fluorescence method was developed for real-time parathyroid identification with high accuracy. This study assesses the clinical utility of this approach. Autofluorescence measurements were obtained from 137 patients (264 parathyroid glands) undergoing parathyroidectomy and/or thyroidectomy. Measurements were correlated to disease state, calcium levels, parathyroid hormone, vitamin D levels, age, sex, ethnicity, and body mass index. Statistical analysis identified which factors affect parathyroid detection. High parathyroid fluorescence was detected consistently and showed wide variability across patients. Near-infrared fluorescence was used to identify 256 of 264 (97%) of glands correctly. The technique showed high accuracy over a wide variety of disease states, although patients with secondary hyperparathyroidism demonstrated confounding results. Analysis revealed body mass index (P < .01), disease state (P < .01), vitamin D (P < .05), and calcium levels (P < .05) account greatly for variability in signal intensity. Age, sex, parathyroid hormone, and ethnicity had no effect. This intrinsic fluorescence-based intraoperative technique can detect nearly all parathyroid glands accurately in real time. Its discrimination capacity is largely unlimited by patient variables, but several factors affect signal intensity. These results demonstrate potential clinical utility of optical guidance for parathyroid detection.

Electrical Impedance Spectroscopy to Aid Parathyroid Identification and Preservation in Central Compartment Neck Surgery: A Proof of Concept in a Rabbit Model.

Accurate identification of parathyroid glands during thyroid surgery is crucial to avoid postthyroidectomy hypocalcemia. Electrical impedance spectroscopy has the potential to differentiate between tissues of different morphology. The aim of this study was to determine the electrical impedance patterns of the thyroid, parathyroid, and other soft tissue structures in the rabbit neck. The central compartments were exposed in 9 freshly culled New Zealand White rabbits. In situ and ex vivo electrical impedance was measured from thyroid lobes, external parathyroid glands, adipose tissue, and strap muscle using the APX100 device. Specimens of all identified glands were sent for histopathology examination. Histology confirmed correct identification of all excised thyroid and parathyroid glands. The impedance was higher for thyroid tissue at lower frequencies and for parathyroid tissue at higher frequencies. Ex vivo electrical impedance spectra were significantly higher compared with the in situ spectra across all frequencies for thyroid and parathyroid tissues (P < .001). The ratio of low to high frequency in situ impedance of thyroid, parathyroid, and muscle was significantly different (P < .001), allowing for differentiation between these tissues. The electrical impedance spectra of rabbit thyroid and parathyroid glands are distinct and different from each other and from skeletal muscle. If these results are replicated in human tissue, they have the potential to improve patient outcomes by achieving early identification and preservation of parathyroid glands.

Potential role for carbon nanoparticles identification and preservation in situ of parathyroid glands during total thyroidectomy and central compartment node dissection.

e17048 Background: Patients undergoing thyroid surgery are at risk for hypoparathyroidism. We hypothesized that carbon nanoparticles identification of parathyroid glands might help maximize parathy...

Intraoperative guidance in parathyroid surgery using near-infrared fluorescence imaging and low-dose Methylene Blue

Identification of diseased and normal parathyroid glands during parathyroid surgery can be challenging. The aim of this study was to assess whether near-infrared (NIR) fluorescence imaging using administration of a low-dose Methylene Blue (MB) at the start of the operation could provide optical guidance during parathyroid surgery and assist in the detection of parathyroid adenomas. Patients diagnosed with primary hyperparathyroidism planned for parathyroidectomy were included. Patients received 0.5 mg/kg MB intravenously directly after start of anesthesia. During the operation, NIR fluorescence imaging was performed to identify parathyroid adenomas. Imaging results were compared with a previous published feasibility study in which 12 patients received MB after intraoperative identification of the adenoma. A total of 13 patients were included in the current study. In 10 of 12 patients with a histologically proven adenoma, the adenoma was fluorescent. Mean signal to background ratio was 3.1 ± 2.8. Mean diameter of the resected lesions was 17 ± 9 mm (range 5-28 mm). Adenomas could be identified up to 145 minutes after administration, which was the longest timespan until resection. Interestingly, in 3 patients, a total of 6 normal parathyroid glands (median diameter 2.5 mm) with a signal to background ratio of 1.8 ± 0.4 were identified using NIR fluorescence imaging. Early administration of low-dose MB provided guidance during parathyroidectomy by identifying both parathyroid adenomas and normal parathyroid glands. In patients in whom difficult identification of the parathyroid adenoma is expected or when normal glands have to be identified, the administration of MB may improve surgical outcome.

Minilaparoscopy-Assisted Hemithyroidectomy and Central Neck Dissection (Level VI) Using Bilateral Breast Approach

Introduction: Minilaparoscopy-assisted thyroidectomy using the bilateral breast approach is a technique for thyroidectomy in patients with thyroid disease. This technique can promote the effect of cosmetology in thyroid surgery. In this video, we outline the instrument, operating room setup, and trocar position, present a minilaparoscopy-assisted hemithyroidectomy and central neck dissection (level VI), and demonstrate recurrent laryngeal nerve and two parathyroids in operation. Materials and Methods: In August 2014, we operated on a 35-year-old female patient. The patient underwent fine-needle aspiration cytology, diagnosed as left papillary thyroid carcinoma. After CT scan and ultrasonic inspection preoperation, the clinical staging is cT1aN0M0 staging I. According to the Chinese thyroid nodule and thyroid cancer guideline,1 we decided to perform left hemithyroidectomy and central neck dissection (level VI) using a bilateral areolar approach. 0.2 mL carbon nanoparticle suspension was injected to the thyroid gland with ultrasonic guidance 2 weeks before operation. The approach starts with the thyroid isthmus liberation that is dissected free from the anterior part of the trachea and transected. Then, the superior pole vessels are divided. The superior pole is then mobilized laterally and the recurrent laryngeal nerve is searched for at the inferior pole. The dissection continues between the nerve and the posterior part of the thyroid progressively, from bottom to top. After the recurrent nerve dissection, the gland can usually be extracted without difficulty, dividing the last vessels in berry ligament holding the gland. While in central neck dissection, first, we confirmed the lateral boundaries of central compartment and identified the recurrent laryngeal nerve. Then completed the central neck dissection. Finally, we present the superior thyroid artery, recurrent laryngeal nerve, and parathyroids after dissection, cleaning up, and closure. Results: The patient who was operated with this technique had a duration of hospitalization of 3 days without any postoperative complication. Carbon nanoparticle suspension is an ideal lymphatic tracer for endoscopic thyroidectomy and central neck dissection, although there is some leakage of carbon nanoparticle suspension in this patient. It does not affect the identification and preservation of recurrent laryngeal nerve and parathyroids. Conclusions: We prefer to operate cN0 thyroid cancer using this technique because it allows us to better identify and preserve the recurrent laryngeal nerve and parathyroids and same boundaries in central neck dissection. Moreover, it brings better cosmetic results for young patients. No competing financial interests exist. Runtime of video: 9 mins 57 secs

Structure-inherent targeting of near-infrared fluorophores for parathyroid and thyroid gland imaging.

The typical method for creating targeted contrast agents requires covalent conjugation of separate targeting and fluorophore domains. In this study, we demonstrate that it is possible create tissue-specific near-infrared fluorophores using the inherent chemical structure. Thus, a single compact molecule performs both targeting and imaging. We use this strategy to solve a major problem in head/neck surgery, the identification and preservation of parathyroid and thyroid glands. We synthesized 700-nm and 800-nm halogenated fluorophores that show high uptake in the specific glands after a single intravenous injection of only 0.06 mg kg−1 in a pig. Using a dual-channel near-infrared imaging system, we demonstrate the real-time, high-sensitivity, unambiguous identification of parathyroid and thyroid glands simultaneously in the context of blood and surrounding soft tissue. This novel technology lays the foundation for head/neck surgery performed with increased precision and efficiency, and potentially lowers morbidity, and a general strategy for targeted near-infrared fluorophore development.

Effectiveness of preventative and other surgical measures on hypocalcemia following bilateral thyroid surgery: a systematic review and meta-analysis.

A variety of measures have been proposed to reduce the incidence of post-thyroidectomy hypocalcemia. The aim of this study was to perform a systematic review and meta-analysis of preventive and other surgical measures on post-thyroidectomy hypocalcemia as reported in the literature. Comprehensive searches of the PubMed, EMBASE, and Cochrane databases were performed, and the quality of included papers was assessed using the Cochrane risk of bias tool or a modified Newcastle-Ottawa Scale (NOS). The results of all included studies were summarized, and meta-analyses were performed where appropriate. Thirty-nine randomized controlled trials (RCTs) and 37 observational studies were included. Measures studied included hemostatic techniques, extent of thyroidectomy and central neck dissection, surgical approach, calcium/vitamin D/thiazide diuretic supplements, parathyroid gland autotransplantation (PGAT) and intraoperative parathyroid gland (PG) identification, truncal ligation of inferior thyroid artery (ITA), preoperative magnesium infusion, and use of magnification loupes and Surgicel. Measures associated with significantly lower rates of transient hypocalcemia in meta-analysis were postoperative calcium and vitamin D supplementation compared to either calcium supplements alone (odds ratio (OR) 0.66; p=0.04) or no supplements (OR 0.34; p=0.007), and bilateral subtotal thyroidectomy (BST) compared to Hartley Dunhill (HD) procedure (OR 0.35; p=0.01). Meta-analyses did not demonstrate any measure to be significantly associated with a reduction in permanent hypocalcemia. This review identified postoperative calcium and vitamin D supplementation and bilateral subtotal thyroidectomy (over HD) as being effective in prevention of transient hypocalcemia. However, the majority of RCTs were of low quality, primarily due to a lack of blinding. The wide variability in study design, definitions of hypocalcemia, and methods of assessment prevented meaningful summation of results for permanent hypocalcemia.

Original technique for preoperative preparation of patients and intraoperative localization of parathyroid adenomas

Surgical approach of single parathyroid adenoma treatment is turning to a less invasive surgery, allowing us to obtain better aesthetic results, reduction of duration of surgical operation, reduction of post-operative morbidity and hospital stay. Tc99m-sestaMIBI scintigraphy is mainly performed for preoperative localization of parathyroid adenomas. Our technique is instead based on the possibility to inhibit the interference of Tc99m-sestaMIBI uptake of the thyroid gland by means of the administration of Lugol's solution. Indeed, to confirm the identification and removal of the hyperfunctional parathyroid, it is accepted as adequate an ex vivo radioactivity count of the adenoma 20% or 40% greater than the value of the post-excisional background radioactivity, in association or not with intraoperative measurement of PTH. This method allows us to perform surgery with no timetable restriction, and to clearly distinguish the radioactivity of parathyroid adenoma from that of the surrounding tissues and thyroid gland.

The Cost of Prolonged Hospitalization due to Postthyroidectomy Hypocalcemia: A Case-Control Study

The aim of this study is to evaluate the additional costs associated with calcium monitoring and treatment as well as evaluate the incidence and predictors of postthyroidectomy hypocalcemia. Methods. This case-control study involved thyroidectomy and completion thyroidectomy patients operated on between January 2012 and August 2013. Cases were defined as requiring calcitriol supplementation, and controls did not require supplementation. Patient (age, sex), nodule (cytology, pathology), surgical data (neck dissection, parathyroid identification, and reimplantation), and hospital stay (days hospitalized in total and after drain removal) were compared. Comparisons were made using t-tests and chi-square tests with an alpha of 0.05. The estimated cost associated with the extended stay was then compared with the cost of supplementation. Results. A total of 191 patients were evaluated (61 cases and 130 controls). Predictors of hypocalcemia include female age, neck dissection, and parathyroid reimplantation. Hypocalcemic patients were hospitalized for a longer period of time after drain removal (2.5 versus 0.8 days, P&lt;0.001), and hospitalization costs after neck drain removal were higher in this group as well (8,367.32$ versus 2,534.32$, P&lt;0.001). Conclusion. Postoperative hypocalcemia incurs significant additional health care costs at both the local and health care system levels.

Label-free intraoperative parathyroid localization with near-infrared autofluorescence imaging.

The inability to accurately localize the parathyroid glands during parathyroidectomy and thyroidectomy procedures can prevent patients from achieving postoperative normocalcemia. There is a critical need for an improved intraoperative method for real-time parathyroid identification. The objective of the study was to test the accuracy of a real-time, label-free technique that uses near-infrared (NIR) autofluorescence imaging to localize the parathyroid. The study was conducted at the Vanderbilt University endocrine surgery center. Patients undergoing parathyroidectomy and/or thyroidectomy were included in this study. To validate the intrinsic fluorescence signal in parathyroid, point measurements from 110 patients were collected using NIR fluorescence spectroscopy. Fluorescence imaging was performed on 6 patients. Imaging contrast is based on a previously unreported intrinsic NIR fluorophore in the parathyroid gland. The accuracy of fluorescence imaging was analyzed in comparison with visual assessment and histological findings. The detection rate of parathyroid glands was measured. The parathyroid glands in 100% of patients measured with fluorescence imaging were successfully detected in real time. Fluorescence images consistently showed 2.4 to 8.5 times higher emission intensity from the parathyroid than surrounding tissue. Histological validation confirmed that the high intrinsic fluorescence signal in the parathyroid gland can be used to localize the parathyroid gland regardless of disease state. NIR fluorescence imaging represents a highly sensitive, real-time, label-free tool for parathyroid localization during surgery. The elegance and effectiveness of NIR autofluorescence imaging of the parathyroid gland makes it highly attractive for clinical application in endocrine surgery.

Effectiveness of preventative and other surgical measures on hypocalcaemia following bilateral thyroid surgery: A systematic review and meta-analysis

Background: Hypocalcaemia following bilateral thyroid surgery is common and is associated with significant short and long term morbidity. The aim of this study was to perform a systematic review and meta-analysis of preventive and other surgical measures on post-thyroidectomy hypocalcaemia as reported in the literature. Methods: Comprehensive searches of PubMed, EMBASE, and Cochrane databases were performed and quality of included papers was assessed using the Cochrane risk of bias tool and a modified NewcastleOttawa Scale (NOS). The results of all included studies were summarised and meta-analyses were performed where appropriate. Results: 39 randomised controlled trials (RCTs) and 37 cohort studies were included. Measures studied included haemostatic techniques, extent of thyroidectomy and central neck dissection, surgical approach, calcium/vitamin D supplements, parathyroid gland auto-transplantation (PGAT) and intra-operative parathyroid gland (PG) identification, truncal ligation of inferior thyroid artery (ITA), and use of magnification loupes and surgical. Measures associated with significantly lower rates of transient hypocalcaemia in meta-analysis were postoperative calcium and vitamin D supplementation compared to either calcium supplements alone (odds ratio (OR) 0.66; 95 per cent confidence interval (CI) 0.45-0.98; p=0.05) or no supplements (OR 0.34; 95 per cent CI 0.15-0.75; p=0.007) and bilateral subtotal thyroidectomy (BST) compared to Hartley Dunhill procedure (HD) procedure (OR 0.35; 95 per cent CI 0.15-0.79; p=0.01). Meta-analyses did not demonstrate any measure to be significantly associated with a reduction in permanent hypocalcaemia. Conclusion: The review identified post-operative calcium and vitamin D supplementation and bilateral subtotal thyroidectomy (over HD) as being effective in prevention of transient hypocalcaemia. However, the majority of RCTs were of low quality, primarily due to lack of blinding. The wide variability in study design, definitions of hypocalcaemia and methods of assessment prevented meaningful summation of results for permanent hypocalcaemia.

Ultrasonographic evaluation of parathyroid hyperplasia in multiple endocrine neoplasia type 1: Positive correlation between parathyroid volume and circulating parathyroid hormone concentration.

There are few reports on parathyroid ultrasonography of multiple endocrine neoplasia type 1 (MEN1). This study investigated the ultrasonographic features of parathyroid glands in 10 patients with MEN1 who underwent preoperative neck ultrasonography and parathyroidectomy between 2006 and 2010 at Toranomon Hospital. We retrospectively analyzed clinical features, laboratory and ultrasonographic data, and pathological diagnosis. A total of 38 parathyroid glands were surgically removed (three to five glands from each patient). All removed parathyroids were pathologically diagnosed as hyperplasia. Seven cases (70.0%) had adenomatous thyroid nodules. Twenty-five enlarged parathyroid glands (65.8%) were detected by preoperative ultrasonography with a detection rate of 81.8% (9/11) and 59.3% (16/27) for patients without and with adenomatous nodules, respectively. Total parathyroid gland weight and potentially predictable total parathyroid volume by preoperative ultrasonography were significantly correlated with preoperative serum intact parathyroid hormone (iPTH) concentration (R=0.97, P<0.001 and R=0.96, P<0.001, respectively). The equation used for prediction of the total volume by ultrasonography was 15×iPTH (pg/ml)-1,000 and that for total weight was 20×iPTH (pg/ml)-1,400. Although adenomatous nodules often coexisted with MEN1 and made identification of enlarged parathyroid glands by ultrasonography difficult, the positive correlation between the predictable parathyroid volume by ultrasonography and serum iPTH suggests that their measurement is useful in the preoperative detection and localization of enlarged parathyroid glands in patients with MEN1. Furthermore, the presence of parathyroid glands that should be resected can be predicted before surgery using the equation proposed here.

Radioactive probe-guided parathyroidectomy for secondary hyperparathyroidism

Background The value of gamma probes in the surgical treatment of secondary hyperparathyroidism (sHPT) was determined. The aim of this study was to enhance the rate of successful total parathyroidectomy in patients with sHPT using intraoperative gamma probe investigations. Methods We retrospectively analyzed the clinical data of 48 sHPT patients between May 2007 and September 2011. Preoperative 99Tcm- methoxyisobutyl isonitrile (MIBI) scintigraphy and high-frequency ultrasonography were used for parathyroid localization. Thirty-five patients (group I) underwent conventional neck exploration and open parathyroidectomy. Thirteen patients (group II) underwent gamma probe-guided total parathyroidectomy and parathyroid transplantation. The two groups were compared in terms of the number of parathyroid resections, operative time, and postoperative changes in the blood levels of parathyroid hormone (PTH), calcium, and phosphate. Results The clinical manifestations, PTH and calcium levels, age distribution, and clinical characteristics did not differ between the two groups. The accuracy of preoperative 99Tcm-MIBI scintigraphy (89.74%) for the diagnosis of hyperparathyroidism did not differ from that of ultrasonography (81.25%). However, the accuracy of 99Tcm-MIBI scintigraphy (66.67%) for localizing hyperfunctioning parathyroids was significantly lower than that of ultrasonography (76.86%). The operation time was significantly longer in group I ((120±25) minutes) than in group II ((90±30) minutes). The accuracy of parathyroid identification was significantly higher in group II (92.59%) than in group I (80.39%). On average, significantly fewer parathyroid specimens were obtained in group I (2.5±0.5) than in group II (3.5±0.5). Compared with group I, group II showed a significant increase (15.4%) in the number of parathyroid resections. The PTH, calcium, and phosphate levels significantly decreased postoperatively in all patients. Conclusions Intraoperative gamma probe examination confirmed that the excised specimen was parathyroid tissue and improved the accuracy of parathyroid resection. The parathyroidectomy rate was increased by 15.4% due to the use of these probes. However, the probes did not detect all ectopic parathyroids, and further research is required to clarify the underlying reasons.