Analysis of false-positive and false-negative results in 99mTc-MIBI SPECT/CT parathyroid imaging

Background

Exact preoperative localization is desirable to perform minimally invasive parathyroidectomy for hyperparathyroidism (HPT). This study aimed to evaluate the diagnostic values of 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) single photon emission computed tomography/computed tomography (SPECT/CT) of parathyroid glands by analyzing the relationship between lesion weight and false-negative (FN) results, as well as to explain the possible reason.

Methods

The data from 314 patients with suspected HPT who underwent 99mTc-MIBI SPECT/CT parathyroid imaging between 2011 and 2022 were retrospectively evaluated. The sensitivity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of parathyroid 99mTc-MIBI SPECT/CT were calculated, and the false-positive (FP) and FN findings were analyzed.

Results

Accurate localization by 99mTc-MIBI SPECT/CT was significantly associated with the parathyroid hormone (PTH) level. The 99mTc-MIBI SPECT/CT for diagnosis/lesion location reached a sensitivity of 84.6%/56.8%, a PPV of 97.3%/98.4%, an NPV of only 23.7%/4.18%, and an accuracy of 83.4%/57.1%, respectively. The largest diameter, shortest diameter, and lesion volume were lower in the FN group than in the TP group. A total of 7 FP cases were found, including 2 cases of thyroid nodules, 4 cases of thyroid tissue, and 1 case of hibernoma. A total of 45 FN patients, including 321 FN lesions, were confirmed, of which parathyroid hyperplasia accounted for 97.8%. Lesion weights greater than 20 µg were able to be detected, but lightweight lesions less than 100 mg were the principal source of FN results, accounting for approximately 39.3%. With lesion weights 0-100, 101-300, 301-1,000, and >1,000 mg, the FN rate was 70.8% (126/178), 51.8% (103/199), 34.6% (81/234), and 8.33% (11/132), respectively.

Conclusions

99mTc-MIBI SPECT/CT parathyroid imaging provides good sensitivity and high specificity in HPT location. Correct localization by 99mTc-MIBI SPECT/CT correlates positively with lesion weight and PTH levels. The smaller the lesion, the higher the FN rate in 99mTc-MIBI SPECT/CT parathyroid imaging, and lesions weighing less than 100 mg are the main source of FN results in 99mTc-MIBI SPECT/CT parathyroid imaging.

Vertical sleeve gastrectomy normalizes circulating glucocorticoid levels and lowers glucocorticoid action tissue-selectively in mice

Objectives

Glucocorticoids produced by the adrenal cortex are essential for the maintenance of metabolic homeostasis. Glucocorticoid activation is catalysed by 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1). Excess glucocorticoids are associated with insulin resistance and hyperglycaemia. A small number of studies have demonstrated effects on glucocorticoid metabolism of bariatric surgery, a group of gastrointestinal procedures known to improve insulin sensitivity and secretion, which were assumed to result from weight loss. In this study, we hypothesize that a reduction in glucocorticoid action following bariatric surgery contributes to the widely observed euglycemic effects of the treatment.

Methods

Glucose and insulin tolerance tests were performed at ten weeks post operatively and circulating corticosterone was measured. Liver and adipose tissues were harvested from fed mice and 11β-HSD1 levels were measured by quantitative RT-PCR or Western (immuno-) blotting, respectively. 11β-HSD1 null mice (Hsd11b1 -/-) were generated using CRISPR/Cas9 genome editing. Wild type and littermate Hsd11b1 -/- mice underwent Vertical Sleeve Gastrectomy (VSG) or sham surgery.

Results

Under the conditions used, no differences in weight loss were observed between VSG treated and sham operated mice. However, both lean and obese WT VSG mice displayed significantly improved glucose clearance and insulin sensitivity. Remarkably, VSG restored physiological corticosterone production in HFD mice and reduced 11β-HSD1 expression in liver and adipose tissue post-surgery. Elimination of the 11β-HSD1/Hsd11b1 gene by CRISPR/Cas9 mimicked the effects of VSG on body weight and tolerance to 1g/kg glucose challenge. However, at higher glucose loads, the euglycemic effect of VSG was superior to Hsd11b1 elimination.

Conclusions

Bariatric surgery improves insulin sensitivity and reduces glucocorticoid activation at the tissular level, under physiological and pathophysiological (obesity) conditions, irrespective of weight loss. These findings point towards a physiologically relevant gut-glucocorticoid axis, and suggest that lowered glucocorticoid exposure may represent an additional contribution to the health benefits of bariatric surgery.

O049 FRAX score assessment of long term follow up thyroid cancer patients

Introduction

Thyroid stimulating hormone (TSH) suppression with Levothyroxine (LT4) following thyroid cancer surgery is recommended in some patients under long term follow up. However, LT4 may cause reduced bone mineral density. We aimed to assess patients in our long-term thyroid cancer follow up clinic for risk to bone health.

Methods

We conducted a review of all patients in the thyroid cancer follow-up clinic and calculation of FRAX score for those that are >40 years old who are followed up in the Endocrine Surgical Service of NUH. Subsequently patients were categorised into risk groups according to the Osteoporosis Group Guideline (2017) and managed accordingly.

Results

78 patients were identified and had ongoing follow up. 23 patients were excluded as they were <40 years old. 10 patients did not want to participate in the study. 45 patients were assessed with the FRAX score. There were 31 female and 14 male patients, mean age 60.8 (±12.3) years. The mean follow up was 75.0 (±78.9) months. 11% (five patients) were found to require treatment for Osteoporosis without a bone mineral density (BMD) scan, 38% (17 patients) were recommended to assess their BMD, 4% had borderline risk to measure BMD, and 47% required lifestyle and dietary modification.

Conclusion

Thyroid cancer patients aged 40 and above represent a cohort in whom osteoporosis is a substantial risk and warrant assessment with a FRAX score.

Take-home message

Thyroid cancer patients aged 40 and above represent a cohort in whom osteoporosis is a substantial risk and warrant assessment with a FRAX score.

Safe provision of elective endocrine surgery operations amid the COVID-19 crisis

INTRODUCTION

The aim of this study was to determine the impact of the COVID-19 pandemic on the provision of clinical services (perioperative clinical outcomes and productivity) of the department of endocrine and general surgery at a teaching hospital in the UK.

METHODS

A retrospective chart review was conducted of all patients who were operated in our department during two periods: 1 April to 31 October 2019 (pre-COVID-19 period) and 1 April to 31 October 2020 (COVID-19 period). The perioperative clinical outcomes and productivity of our department for the two time periods were compared.

RESULTS

In the pre-COVID-19 period, 130 operations were carried out, whereas in the COVID-19 group, this reduced to 89. The baseline characteristics between the two groups did not significantly differ. Parathyroid operations decreased significantly by 68% between the two study periods. Overall, during the COVID-19 phase, the department maintained 68% of its operating workload compared with the respective 2019 time period. The clinical outcomes for the patients who had a thyroid/parathyroid/adrenal operation were not statistically different for the two study periods. There were no COVID-19 related perioperative complications for any of the operated patients and no patient tested positive for COVID-19 while an inpatient. For the COVID-19 group, the department maintained 67% of its outpatient appointments for endocrine surgery and 26% for general surgery pathologies.

CONCLUSIONS

The COVID-19 pandemic significantly reduced the clinical activity of our department. However, it is possible to continue providing clinical services for urgent/cancer cases with the appropriate safety measures in place.

Thyroid lobectomy for low-risk thyroid cancers

BACKGROUND

The 2016 American Thyroid Association (ATA) guidelines proposed thyroid lobectomy for low-risk differentiated thyroid cancer (DTC); however, this approach is yet to be widely adopted. The aim of the study was to review our practice over three years following the publication of these guidelines identifying patients who underwent lobectomy-only for low-risk DTC in two regional units in the same multidisciplinary team (MDT).

METHOD

A retrospective review of patients who were operated between January 2016 and December 2018 was carried out.

RESULTS

In total, 288 patients undergoing thyroid surgery were included. The preoperative distribution of cytology was: Thy 1 or 2 in 46, THY3a in 57, THY3f in 154, THY4 in 18 and THY5 in 13 patients. Median size of nodules was 26mm (range 1-70mm). DTC was diagnosed in 95 patients (33%). Overall, 39% (n = 37) of patients underwent completion thyroidectomy according to ATA recommendations on size or adverse histological features. The only variable associated with likelihood of completion was tumour size (p < 0.05, OR 1.14). Ten patients were discharged following surgery with no further follow-up as they had T1a/b well-differentiated DTC with no high-risk histological features.

CONCLUSION

Lobectomy-only appears to be the current surgical practice in two-thirds of patients presenting to our regional units with differentiated thyroid carcinoma. In the context of the current drive to reduce the extent of treatment for low-risk thyroid cancer, there is a need for a more homogeneous approach to these patients and for protocols for long-term follow-up after lobectomy-only.

1364 Quality Control of Discharge Summaries for Endocrine Surgery Patients; A Closed Loop Audit

Aim

A patient's discharge summary (TTO) should be accurate. Most of them are conducted by junior doctors at the beginning of their medical training. The information mentioned in a TTO ensures patient safety, continuity of care as well as correct clinical coding for the NHS. Therefore, a re-audit was designed to check the quality of the discharge summaries of endocrine surgical patients In Nottingham City Hospital i.e., the type of operation, diagnosis, or postoperative instructions.

Method

The first cycle included all the TTOs for the endocrine surgical patients operated from April 2018 to November 2018. Then we re-audited those who had endocrine surgeries from April 2019 to November 2019. NOTIS e-TTO, Bluespier theatre lists and Medway were used to retrieve the data. All general surgery patients were excluded.

Results

142 and 104 patients TTOs were included in each audit cycle, respectively. Type of operation was improved from 84% to 95% in the second cycle. Correct diagnosis was reported from 68% to 72% in the second cycle audit.

Conclusions

The introduction of electronic operation notes in our practice improved the correct clinical coding for the type of operation mentioned in the TTO. The accuracy of correct diagnosis remains suboptimal. Therefore, education of junior doctors and an idea of double-checking from a more senior colleague should be assessed.

Gastric perforation secondary to Rapunzel syndrome

Rapunzel syndrome is rare and describes a trichobezoar that extends through the pylorus into the jejunum, ileum or even the colon. Due to the large intraluminal size and weight they can attain, acute presentations of obstruction or perforation may occur. We report a case of a 17-year-old girl who presented to the emergency department following a syncopal episode. On examination, a left upper quadrant mass was appreciated with no signs of peritonism. Contrast-enhanced CT demonstrated a giant trichobezoar with resulting gastric perforation and intra-abdominal free fluid. Laparotomy and gastrotomy were performed and the patient had an uneventful recovery with psychiatric review prior to discharge. Though uncommon, bezoars should be included in our differential diagnosis as they can present in various ways owing to their size and weight. This case illustrates the risk of gastric perforation with large gastric bezoars.

Comparative performances of nomograms and conditional survival after resection of adrenocortical cancer

Background

Adrenocortical carcinomas (ACCs) carry a poor prognosis. This study assessed the comparative performance of existing nomograms in estimating the likelihood of survival, along with the value of conditional survival estimation for patients who had already survived for a given length of time after surgery.

Methods

This was an observational study based on a prospectively developed departmental database that recorded details of patients operated for ACC in a UK tertiary referral centre.

Results

Of 74 patients with ACC managed between 2001 and 2020, data were analysed for 62 patients (32 women and 30 men, mean(s.d.) age 51(17) years) who had primary surgical treatment in this unit. Laparoscopic (9) or open adrenalectomies (53) were performed alone or in association with a multivisceral resection (27). Most of the tumours were left-sided (40) and 18 were cortisol-secreting.

Overall median survival was 33 months, with 1-, 3- and 5-year survival rates of 79, 49, and 41 per cent respectively. Age over 55 years, higher European Network for Study of Adrenal Tumours stage, and cortisol secretion were associated with poorer survival in univariable analyses. Four published nomograms suggested widely variable outcomes that did not correlate with observed overall survival at 1, 3 or 5 years after operation. The 3-year conditional survival at 2 years (probability of surviving to postoperative year 5) was 65 per cent, compared with a 5-year actuarial survival rate of 41 per cent calculated from the time of surgery.

Conclusion

Survival of patients with ACC correlates with clinical parameters but not with published nomograms. Conditional survival might provide a more accurate estimate of survival for patients who have already survived for a certain amount of time after resection.

Understanding the clinical course of genotype-negative MEN1 patients can inform management strategies

BACKGROUND

It is unclear whether genotype-negative clinical multiple endocrine neoplasia type 1 patients derive equal benefit from prospective surveillance as genotype-positive patients.

METHODS

In this retrospective cohort study, we compared genotype-negative patients with clinical multiple endocrine neoplasia type 1 with genotype-positive index cases. Primary outcome was age-related penetrance of manifestations; secondary outcomes were disease-specific survival and clinical course of endocrine tumors.

RESULTS

We included 39 genotype-negative patients with clinical multiple endocrine neoplasia type 1 (Male: 33%) and 63 genotype-positive multiple endocrine neoplasia type 1 index cases (Male: 59%). Genotype-negative patients with clinical multiple endocrine neoplasia type 1 were 65 years old at last follow-up; genotype-positive multiple endocrine neoplasia type 1 index cases were 50 (P < .001). Genotype-negative patients with clinical multiple endocrine neoplasia type 1 were significantly older at their first and second primary manifestation. Only 1 developed a third primary manifestation. No genotype-negative patients with clinical multiple endocrine neoplasia type 1 with primary hyperparathyroidism and a pituitary adenoma developed a duodenopancreatic neuroendocrine tumor. Disease-specific survival was significantly better in genotype-negative patients with clinical multiple endocrine neoplasia type 1. In genotype-negative patients with clinical multiple endocrine neoplasia type 1, primary hyperparathyroidism was single-gland disease in 47% of parathyroidectomies versus 0% in genotype-positive multiple endocrine neoplasia type 1 index cases. In genotype-negative patients with clinical multiple endocrine neoplasia type 1, 17% of duodenopancreatic neuroendocrine tumors were multifocal versus 68% in genotype-positive multiple endocrine neoplasia type 1 index cases. Genotype-negative patients with clinical multiple endocrine neoplasia type 1 had more pituitary macroadenomas, fewer prolactinomas, and more somatotroph adenomas.

CONCLUSION

Genotype-negative patients with clinical multiple endocrine neoplasia type 1 have a different clinical course than genotype-positive multiple endocrine neoplasia type 1 index cases. This may support a separate classification and a tailored surveillance regimen. Of the genotype-negative patients with clinical multiple endocrine neoplasia type 1 who had parathyroidectomy, almost half had no evidence of multigland disease and may be potential candidates for a more targeted single-gland approach.

Using a Novel Diagnostic Nomogram to Differentiate Malignant from Benign Parathyroid Neoplasms

We sought to develop an immunohistochemical (IHC) tool to support the diagnosis of parathyroid carcinoma (PC) and help differentiate it from atypical parathyroid neoplasms (atypical) and benign adenomas. Distinguishing PC from benign parathyroid neoplasms can be challenging. Many cases of PC are histopathologically borderline for definitive malignancy. Recently, individual IHC biomarkers have been evaluated to aid in discrimination between parathyroid neoplasms. PC, atypical parathyroid neoplasms, and parathyroid adenomas treated at our institution from 1997 to 2014 were studied retrospectively. IHC analysis was performed to evaluate parafibromin, retinoblastoma (RB), protein gene product 9.5 (PGP9.5), Ki67, galectin-3, and E-cadherin expression. Receiver operating characteristic (ROC) analysis and multivariable logistic regression model for combinations of biomarkers were evaluated to classify patients as PC or atypical/adenoma. A diagnostic nomogram using 5 biomarkers was created for PC. Sixty-three patients were evaluated. The percent staining of parafibromin (p < 0.0001), RB (p = 0.04), Ki67 (p = 0.02), PGP9.5 (p = 0.04), and Galectin-3 (p = 0.01) differed significantly in the three diagnostic groups. ROC analysis demonstrated that parafibromin had the best performance in discriminating PC from atypical/adenoma; area under the curve (AUC) was 81% (cutoff, 92.5%; sensitivity rate, 64%; specificity rate, 87%). We created a diagnostic nomogram using a combination of biomarkers; AUC was 84.9% (95% confidence interval, 73.4-96.4%). The optimism-adjusted AUC for this model was 80.5% (mean absolute error, 0.043). A diagnostic nomogram utilizing an immunoexpression, a combination of immunohistochemical biomarkers, can be used to help differentiate PC from other parathyroid neoplasms, thus potentially improving diagnostic classification.

18Fluorocholine PET/CT scanning with arterial phase-enhanced CT is useful for persistent/recurrent primary hyperparathyroidism: first UK case series results

INTRODUCTION

Redo parathyroidectomy for persistent/recurrent primary hyperparathyroidism is associated with a higher risk of complications and should be planned only with convincing localisation. We assessed whether ¹⁸fluorocholine positron emission tomography/computed tomography could identify parathyroid adenoma(s) in patients with persistent/recurrent primary hyperparathyroidism and negative conventional scans.

MATERIALS AND METHODS

A departmental database was used to identify patients with failed localisation attempts (sestamibi single photon emission computed tomography/computed tomography and/or computed tomography/magnetic resonance imaging and/or selective parathyroid hormone sampling) after previous unsuccessful surgery for primary hyperparathyroidism. ¹⁸Fluorocholine positron emission tomography was performed in all patients and redo surgery offered to those with positive findings.

RESULTS

¹⁸Fluorocholine positron emission tomography incorporating arterial and portal phase enhanced computed tomography was performed in 12 patients with persistent/recurrent primary hyperparathyroidism (four men and eight women). Seven patients (58%) were cured after excision of adenomas located in ectopic positions (n = 3) or in anatomical position (n = 4). Five patients (42%) had persistent hypercalcaemia and repeat ¹⁸fluorocholine scan confirmed that the area highlighted on preoperative scans was excised. The arterial phase enhancement of the computed tomography was significantly different between cured and not-cured patients (P = 0.007). All seven cured patients had either a strong or weak enhancing pattern on computed tomography. Standardised uptake value at 60 minutes in patients with successful surgery (range 2.7-15.7, median 4.05) was higher than in patients with failed surgery (range 1.8-5.8, median 3.2) but was not statistically significant (P = 0.300).

DISCUSSION

¹⁸fluorocholine scanning can identify elusive parathyroid adenomas, including those that are ectopic, and is useful in the management of patients with persistent/recurrent primary hyperparathyroidism when first-line scans are negative. The grading of the arterial phase of computed tomography can help to differentiate between true adenomas and false positive targets (lymph nodes).

Long-term quality of voice is usually acceptable after initial hoarseness caused by a thyroidectomy or a parathyroidectomy

Background

Vocal cord (VC) palsy following a thyroidectomy or parathyroidectomy can result in significant morbidity for the patient. We aimed to investigate the incidence of VC palsy in a tertiary referral Institution, track the management of these cases and record the long-term outcomes and VC recovery rates.

Methods

Retrospective review of all thyroidectomy/parathyroidectomy operations performed over 11 years. Patients with an unequivocal hoarse voice postoperatively were included. We analysed the patient's clinical characteristics and voice outcomes, operative, pathology and laryngoscopy reports during their follow-up.

Results

Ten patients fitted the inclusion criteria and were analysed. Median age at date of operation was 47.5 years (range, 16-81 years) and the M:F ratio was 1:2.3 (M:3, F:7). The median FU was 62.5 months (range, 12-144 months). The median hospital stay was 1.5 days (range, 1-87 days). There were 7 recurrent laryngeal nerve (RLN) injuries by manipulation, 1 case of RLN resection, 1 inadvertent division (with primary nerve repair) and 1 RLN was shaved off the thyroid. Long-term voice outcomes for the 7 patients with an RLN manipulation injury were: 3/7 patients had normal voice, 3/7 had moderate hoarseness and 1/7 had long-term hoarseness. The long-term voice outcome of the patient with RLN shaving off the thyroid gland was excellent while the 2 remaining patients (RLN resection and inadvertent division) needed 12 and 18 months respectively to achieve a normal quality of voice. Four out of the 10 patients had permanent VC palsy in the long-term and their voice outcomes varied: 1 patient had a normal voice, 2 patients had moderate hoarseness and 1 patient had persistent hoarseness. Only 1/10 patients did not show any voice improvement after 12 months.

Conclusions

In the vast majority of cases post-operative hoarseness due to RLN palsy improves in the long-term, albeit voice may not return completely to normal.

Comprehensive Genomic Characterization of Parathyroid Cancer Identifies Novel Candidate Driver Mutations and Core Pathways

CONTEXT

Elucidating the genomic landscape of sporadic parathyroid carcinoma (PC) has been limited by low tumor incidence.

OBJECTIVE

Identify driver mutations of sporadic PC and potential actionable pathways.

METHODS

Patients undergoing surgical resection for sporadic PC between 1980 and 2016 at MD Anderson Cancer Center were identified. Patients with sporadic PC according to World Health Organization diagnostic criteria and with available formalin-fixed, paraffin-embedded (FFPE) PC tumor tissue were included and their clinical data analyzed to assess extent of disease. Patients with parathyroid tumors of uncertain malignancy or atypical parathyroid neoplasms were excluded. Thirty-one patients meeting diagnostic criteria had available tissue for analysis. FFPE PC tumors were subjected to DNA extraction and next-generation whole-exome sequencing. All variant calls are single-algorithm only. Twenty-nine samples passed quality assurance after DNA extraction.

MAIN OUTCOME MEASURES

Somatic or private germline mutations present in sporadic PC and identification of pathways involved in tumorigenesis.

RESULTS

We identified 35 genes with considerable mutational load; only eight genes were previously identified in other PC cohorts. These genes mediate critical processes, including chromosome organization, DNA repair, and cell cycle regulations. Gene mutations involved in MAPK signaling and immune response are also heavily implicated. These findings are limited by inherent molecular artifacts in FFPE tissue analysis and the absence of matched germline DNA. Additionally, variant calls are only single algorithm and may include false-positive/negative calls.

CONCLUSION

We identified 33 candidate driver genes of sporadic PC, in addition to previously known driver genes CDC73 and MEN1.

Seventeen Cases of Primary Hyperparathyroidism in Pregnancy: A Call for Management Guidelines

Context

The risks of primary hyperparathyroidism (pHPT) to pregnant women and their fetuses appear to increase commensurate with serum calcium levels. The management strategy for pHPT must be adapted in pregnancy and should reflect the severity of hypercalcemia. However, no guidelines exist to assist clinicians.

Methods

The experience of a high-volume multidisciplinary endocrine surgical service in treating a consecutive series of pregnant women with pHPT referred for parathyroidectomy is presented and data are compared with a nonpregnant cohort with pHPT. A review of pHPT and pregnancy outcomes in the literature is provided.

Results

Seventeen pregnant women and 247 age range-matched nonpregnant women with pHPT were referred for surgery over 11 years. Mean serum calcium level was higher in the pregnant cohort (2.89 vs 2.78 mmol/L; P = 0.03). Preoperative localization with ultrasound succeeded in eight pregnant women (47%) and sestamibi scanning did in two of six (33% imaged preconception), compared with 84 (34%) and 102 (42%) control subjects, respectively (not significant). Parathyroidectomy was performed under general anesthesia between 12 and 28 weeks' gestation with no adverse pregnancy outcomes resulting. Cure rate was 100% vs 96% in controls.

Conclusion

pHPT in pregnancy is a threat to mother and child. Medical management may be appropriate in mild disease, but in moderate to severe disease, parathyroidectomy under general anesthesia in the second trimester is safe. Localization using ionizing radiation/MRI is unnecessary, because surgical intervention in a high-volume multidisciplinary setting has excellent outcomes. Guidelines on the topic would assist clinicians.

Operation duration and adrenal gland size, but not BMI, are correlated with complication rate for posterior retroperitoneoscopic adrenalectomy for benign diseases

BACKGROUND

We sought to determine whether obesity is correlated with complications after posterior retroperitoneoscopic adrenalectomy for benign diseases and to develop surrogate markers of abdominal fat in preoperative computed tomography.

METHODS

We conducted a retrospective chart review of all patients who had undergone posterior retroperitoneoscopic adrenalectomy and preoperative computed tomography between January 1, 2008 and December 31, 2015. The cross-sectional components of fat assessed by computed tomography included total fat area, subcutaneous fat area, retroperitoneal fat area, and peritoneal fat area. The patients were grouped into 2 categories according to the absence or presence of a postoperative complication (the no-complications group and the complications group, respectively).

RESULTS

Of 116 study patients, 20 patients (17%) had a postoperative complication. Operations of greater duration and smaller adrenal gland size were significantly correlated with complications both in univariate and multivariate analyses. Body mass index, total fat area, subcutaneous fat area, retroperitoneal fat area, peritoneal fat area, and distance of skin to muscle (in axial and sagittal images) correlated with complications in univariate analysis but not in multivariate analysis. In the no-complications group, the removed adrenal gland was larger than that removed in the complications group (6 vs 4 cm, respectively, P = .001), whereas the complications group had a greater operative duration (139 vs 104 min, respectively, P = .001) and a greater duration of hospital stay (3 days vs 1 day, respectively, P = .001).

CONCLUSION

In this study, operations of greater duration and smaller adrenal gland size were better predictors of complications after posterior retroperitoneoscopic adrenalectomy for benign disease than measures of obesity, including body mass index.

Gender differences in bone mineral density in patients with sporadic primary hyperparathyroidism

CONTEXT

Primary hyperparathyroidism reduces bone mineral density, which increases the risk of fracture.

OBJECTIVE

To investigate differences in bone mineral density and clinical characteristics after parathyroidectomy between men and women (premenopausal and postmenopausal) with sporadic primary hyperparathyroidism.

DESIGN

This is a retrospective study of adult patients who underwent parathyroidectomy in a tertiary referral center from 1990 to 2013.

PATIENTS

A total of 1529 patients underwent parathyroidectomy during the study period; 80 patients met the inclusion criteria. Of these, 24 were men and 56 were women (10 premenopausal and 46 postmenopausal).

MEASUREMENTS

Demographics, preoperative and postoperative biochemical analysis, preoperative and postoperative T-scores, preoperative Z-scores, preoperative and postoperative absolute bone mineral density values, and percentage change in bone mineral density from baseline to 12 ± 6 months after parathyroidectomy in the lumbar spine, femoral neck, total hip and distal one-third of the nondominant radius.

RESULTS

Preoperative 24-hour urinary calcium levels were significantly higher in men than in women overall (P = 0.02) and postmenopausal women (P = 0.01). Men had significantly lower preoperative Z-scores than women overall, premenopausal women and postmenopausal women. Men had greater percentage change of increase in bone mineral density in the femoral neck than did women overall (2.77%; P = 0.04) and postmenopausal women (2.98%; P = 0.03) 1 year after parathyroidectomy.

CONCLUSIONS

From this study, men demonstrated a greater improvement of bone mineral density in the femoral neck from baseline after parathyroidectomy compared with women.

Metastasis to the thyroid gland from a tonsil squamous cell carcinoma

We present a case of rare metastasis of tonsil squamous cell carcinoma to the thyroid gland, after 2 years of treatment without recurrence at the primary site. The patient had incidental finding of a nodule in the left lobe of the thyroid gland during a screening scan for his previous tonsil squamous cell carcinoma that was treated surgically 2 years ago. The patient was completely asymptomatic with normal thyroid function tests. After further investigations and discussion in the MDT meeting, the patient underwent left thyroid lobectomy as a definitive treatment for his thyroid metastasis.

Establishing a successful rat model of duodenal- jejunal bypass: A detailed guide

Gastric bypass surgery, an operation that restricts the stomach and bypasses the duodenum and part of the jejunum, results in major improvement or remission of type 2 diabetes. Duodenual-jejunal bypass was developed by one of the authors (FR) as an experimental, stomach-sparing variant of gastric bypass surgery to investigate weight-independent mechanisms of surgical control of diabetes. Duodenual-jejunal bypass has been shown to improve various aspects of glucose homeostasis in rodents and in humans, thus providing an experimental model for investigating mechanisms of action of surgery and elusive aspects of gastrointestinal physiology. Performing duodenual-jejunal bypass in rodents, however, is associated with a steep learning curve. Here we report our experience with duodenual-jejunal bypass and provide practical tips for successful surgery in rats. Duodenual-jejunal bypass was performed on 50 lean rats as part of a study aimed at investigating the effect of the procedure on the physiologic mechanisms of glucose homeostasis. During the study, we have progressively refined details of anatomic exposure, technical aspects of duodeno-jejunostomy and peri-operative care. We analysed the role of such refinements in improving operative time and post-operative mortality. We found that refinement of exposure methods of the gastro-duodenal junction aimed at minimizing tension on small visceral vasculature, technical aspects of duodeno-jejunal anastomosis and peri-operative management played a major role in improving the survival rate and operative time. Overall, an experimental model of duodenual-jejunal bypass was successfully reproduced. Based on this experience, we describe here what we believe are the most important technical tips to reduce the learning curve for the procedure.

Risk stratification of 282 differentiated thyroid cancers found incidentally in 1369 total thyroidectomies according to the 2015 ATA guidelines; implications for management and treatment

Introduction The purpose of this study was to evaluate the incidence of incidental differentiated thyroid carcinoma in thyroid operations for a benign preoperative diagnosis, to identify the risk factors involved and to risk stratify the cancer patients according to the 2015 American Thyroid Association (ATA) guidelines. Materials and methods The study was a retrospective review of all thyroidectomy operations performed in a single institution (January 2004 to January 2009). We excluded patients with a preoperative diagnosis of thyroid malignancy. Results Incidental differentiated thyroid carcinoma was diagnosed in 282/1369 patients (21%). The incidental group had a significantly higher number of males (19% vs 14%, P = 0.033) and a higher number of patients with histopathological evidence of thyroiditis (35% vs 25%, P = 0.004). There was a higher number of lymph nodes present in the incidental group but numbers did not reach statistical significance (17% vs 13%, P = 0.079). There were 270 cases in the ATA low-risk group (96%) and 12 cases in the ATA intermediate-risk group (4%). Patients with an ATA intermediate risk had a statistically higher number of capsule invasion, extrathyroidal extension and angioinvasion (P < 0.001, P < 0.001 and P < 0.001, respectively). Overall, 22% of patients with an incidental differentiated thyroid carcinoma should be considered for radioactive iodine 131I treatment. 29 of the 191 patients in American Joint Committee on Cancer stage I should be considered for radioactive iodine treatment (15%). Conclusions Males and patients with thyroiditis are at a higher risk for an incidental differentiated thyroid carcinoma. One of every five of patients diagnosed with cancer will need radioactive iodine treatment, even some patients with stage I disease.

Clinical features and prognosis of thymic neuroendocrine tumours associated with multiple endocrine neoplasia type 1: A single-centre study, systematic review and meta-analysis

OBJECTIVE

Thymic neuroendocrine tumour (TH-NET) accounts for almost 20% of multiple endocrine neoplasia type 1 (MEN1)-associated mortality. Identifying risk factors for the development of these rare tumours and prognostic factors for clinical outcomes will be helpful in clinical practice.

DESIGN AND PATIENTS

We performed a retrospective analysis of patients treated for TH-NET associated with MEN1 in a single institution and meta-analysis of literature reports. We used a fixed effect model to pool results across studies to evaluate the prevalence, clinical features and prognosis.

RESULTS

TH-NET was detected in 9 (7.4%) of 121 patients with MEN1 seen in our institution, and 5 (55.6%) were women. Seven additional studies were identified through a systematic review of the literature. The pool estimate of TH-NET prevalence was 3.7% (n = 99) in MEN1 (n = 2710), sex ratio was 79:20 (male vs female), and the median age at diagnosis was 43.0 years (range, 16.0-72.0 years). Forty-three patients died with a median survival time of 8.4 years. Older age at diagnosis (HR = 1.4, 95% CI = 1.0-1.8, P = .03), maximum tumour diameter (HR = 1.5, 95% CI = 1.0-2.3, P = .04) and presence of metastasis (HR = 1.6, 95% CI = 1.0-2.5, P = .04) were associated with worse outcome. A male predominance (91.9% vs 59.5%, P < .001) and history of smoking (59.0% vs 23.5%, P = .015) were more common in American/European series compared to Asian reports.

CONCLUSION

TH-NET is a rare but fatal component of MEN1. Earlier detection of TH-NET in patients with MEN1 may be recommended which should theoretically result in better outcomes. Different genetic backgrounds (race) appear to result in clinical difference.

Inadvertent parathyroidectomy risk factors in 1,373 thyroidectomies-male gender and presence of lymphadenopathy, but not size of gland, independently increase the risk

Background

Inadvertent parathyroidectomy (IP) during thyroid operations is a recognised phenomenon. We evaluated the incidence of IP during thyroid operations in a large case-series and identified the risk factors involved.

Methods

Retrospective review of all thyroidectomy operations [total thyroidectomies (TT) and near-total thyroidectomies (NTT)] performed in a single institution from January 2004 to January 2009. We excluded re-operative cases, combined thyroid and parathyroid pathology, hemithyroidectomies and neck lymph nodes (LN) dissections. Pathology reports were correlated with operative records to identify the details of the IP glands. Relevant data (patient demographic data, preoperative diagnosis and operative details) were collected and a logistic regression was performed.

Results

One thousand three hundred and seventy-three patients were included in our study, 1,149 of them females (84%). IP rate was 11.3%. Univariate analysis showed that gender, thyroid gland weight, thyroid activity pre-operatively and type of operation are associated with IP. Logistic regression analysis has shown that female gender and the absence of LN in pathology were associated with less likelihood in developing IP than males and patients with presence of LN (P=0.051 and 0.014 respectively). IP occurs 2.14 and 2.28 times more often in TT and NTT when compared to the combination of TT and NTT (P=0.047 and 0.048 respectively).

Conclusions

We present the largest single-centre case series on this topic, to our knowledge. The presence of LN, female gender and the type of operation are positively correlated to the IP rate. These factors could alert the surgeon to consider early calcium supplementation if the parathyroid glands (PG) have not been identified intraoperatively.

Postoperative local-regional radiation therapy in the treatment of parathyroid carcinoma: The MD Anderson experience of 35 years

PURPOSE

We aimed to investigate outcomes of locoregional radiation therapy (XRT) in parathyroid carcinoma (PC) patients at a single institution over 35 years.

METHODS AND MATERIALS

Retrospective review of PC patients who received postoperative locoregional XRT (1980-2015). Patients were grouped according to XRT after PC initial operation or after salvage surgery. All patients with a histopathological diagnosis of PC who had postoperative locoregional XRT at our institution were included. All patients with a histopathological diagnosis of uncertain malignancy, suggestive for malignancy, or atypical parathyroid tumors and those who had XRT outside our institution were excluded.

RESULTS

Eight patients received XRT, 4 in each group, with a median follow-up of 12.5 years. The 4 patients who had XRT after initial surgery all had an oncologic operation, including ipsilateral thyroid lobectomy and central neck dissection, and all of these patients were disease-free at last follow-up. Of the 4 patients who received XRT after salvage surgery, only 1 remained disease free. There were no major complications/long-term side effects associated with XRT.

CONCLUSIONS

XRT is well tolerated as postoperative locoregional treatment of patients with PC. Whether it is needed, and the timing of administering XRT, remains to be established.

Is estrogen exposure a protective factor for pancreatic neuroendocrine tumours in female patients with multiple endocrine neoplasia syndrome type 1?

OBJECTIVE

Pancreatic neuroendocrine tumours (PNETs) are the most common cause of death in patients with multiple endocrine neoplasia type 1 (MEN1). Women have been shown to have improved survival, which may suggest a possible protective effect of female sex hormones. The aim of this study was to evaluate the relationship between estrogen exposure and PNET tumourigenesis, tumour growth and survival in female MEN1 patients with these tumours.

DESIGN

We performed a retrospective chart review of the existing MEN1 database in our institution. Detailed information about female patients' menstrual and reproductive history, and PNET clinicopathologic characteristics was collected. Questionnaires regarding estrogen exposure were used to collect information that was missing in the database.

PATIENTS

Of 293 confirmed MEN1 cases, 141 women met the inclusion criteria.

MEASUREMENTS

We used measures of cumulative estrogen exposure time (CEET), parity, live birth pregnancies and bilateral oophorectomy to estimate estrogen exposure.

RESULTS

There was no significant association between CEET and time to PNET diagnosis (hazard ratio = 0·966, P = 0·380). For the correlation between estrogen exposure and PNET type, size, numbers, distant metastasis, lymph node metastasis, lymphovascular invasion, AJCC (American Joint Committee on Cancer) stage and overall survival, only CEET was significantly correlated with PNET size (P = 0·043).

CONCLUSIONS

In female patients with MEN1, estrogen exposure may inhibit PNET growth. A demonstrable protective effect against PNET tumourigenesis, tumour growth and survival of patients with these tumours may require a larger cohort.

Considering Postoperative Functional Hypoaldosteronism after Unilateral Adrenalectomy

Conn's Syndrome is an uncommon condition. Patients who have undergone adrenalectomy in the early postoperative period can demonstrate biochemical hypoaldosteronism. Given the rare nature of this phenomenon we investigated its incidence and whether it translated to clinical findings. A single-institution retrospective review of all patients with biochemically proven hyperaldosteronism from 2005 to 2014 that underwent unilateral adrenalectomy. A total of 29 patients fit the inclusion criteria. Functional hypoaldosteronism had appreciated in 18/29 (62%) patients, whereas 11 patients (38%) had normal postoperative aldosterone. No significant differences between diagnostic groups were found in terms of clinical outcomes (length of stay, postoperative symptomatology, and readmissions P = 0.669, 0.154, and 0.268, respectively). Two (7%) patients required medical therapy. Biochemical evidence of functional hypoaldosteronism was identified in two-thirds of patients undergoing unilateral adrenalectomy. Although contralateral aldosterone suppression can be anticipated, the phenotypic response varied and the outcomes were similar to patients with normal aldosterone levels. Current guidelines make no formal recommendations for assessment of hypoaldosteronism after adrenalectomy, resulting in varying practice paradigms. Surgeons should consider the risk of postoperative hypoaldosteronism in these patients and counsel patients accordingly. Prospective investigations should be performed to assist in development of an outcomes-based care delivery model for these patients.

Prognostic Scoring System to Risk Stratify Parathyroid Carcinoma

BACKGROUND

Parathyroid carcinoma is a rare endocrine malignancy that lacks an established system for risk categorization. This study evaluated a prognostic scoring system for recurrence-free survival (RFS) of patients with parathyroid carcinoma.

STUDY DESIGN

Patients diagnosed and confirmed to have parathyroid carcinoma and who were treated between 1980 and 2016 at The University of Texas MD Anderson Cancer Center were studied retrospectively. Univariate and multivariate Cox proportional hazards regression analyses of RFS were conducted. A prognostic scoring system was created based on multivariate analysis.

RESULTS

Sixty-eight patients were evaluated. After a median follow-up of 4.6 years, 26 patients experienced a recurrence. The Kaplan-Meier RFS rates were 85% at 1 year (95% CI 77% to 95%), 67% at 2 years (95% CI 55% to 81%), and 51% at 10 years (95% CI 36% to 72%) after initial operation. Multivariate analysis demonstrated that age older than 65 years, serum calcium level >15 mg/dL, and vascular invasion were negatively correlated with RFS rate. Combining these adverse variables into a prognostic scoring system, we stratified patients into 3 risk groups: low (0 variable; 2-year RFS rate, 93%), moderate (1 variable; 2-year RFS rate, 72%), and high (2 variables; 2-year RFS rate, 27%) (p = 0.001 [log-rank test]; concordance index, 0.70; 95% CI 0.47 to 0.92).

CONCLUSIONS

A prognostic scoring system using vascular invasion, age, and serum calcium level at initial parathyroidectomy can be used to predict RFS. This categorization might be helpful for clinical decisions relative to the timing and use of adjuvant therapy. Comprehensive validation using multiple cohorts will be needed to confirm applicability.

Operative intervention for primary hyperparathyroidism offers greater bone recovery in patients with sporadic disease than in those with multiple endocrine neoplasia type 1-related hyperparathyroidism

BACKGROUND

We investigated whether the outcome of bone disease of primary hyperparathyroidism differs in multiple endocrine neoplasia type 1-associated disease and sporadic hyperparathyroidism at 1-year postoperatively.

METHODS

Multiple endocrine neoplasia type 1/hyperparathyroidism and sporadic hyperparathyroidism patients who underwent parathyroidectomy from 1990 to 2013 and dual-energy x-ray absorptiometry at baseline and 1-year postoperatively were included. Preoperative and postoperative dual-energy x-ray absorptiometry measurements (bone mineral density and Z-score at the lumbar spine, total hip, and femoral neck) were analyzed.

RESULTS

We evaluated 14 multiple endocrine neoplasia type 1/hyperparathyroidism and 104 sporadic hyperparathyroidism patients. The preoperative Z-scores at the lumbar spine, total hip, and femoral neck were lower in the multiple endocrine neoplasia type 1/hyperparathyroidism group (P = .05, P = .04, and P = .0081, respectively). Comparison of preoperative and postoperative dual-energy x-ray absorptiometry measurements demonstrated that the multiple endocrine neoplasia type 1/hyperparathyroidism group had a significantly higher Z-score at the lumbar spine (P = .02) at 1 year after operation, whereas the sporadic hyperparathyroidism group had a significantly higher Z-score at the lumbar spine, total hip, and femoral neck (P < .0001, P = .0004, and P = .0001) and higher bone mineral density at the lumbar spine (P = .0001).

CONCLUSION

Long-term monitoring of these patients using dual-energy x-ray absorptiometry is required to assess outcomes and facilitate decisions on the timing of operative intervention.

Measuring the Pharmacokinetic Properties of Drugs with a Novel Surgical Rat Model

Purpose/aim of the study: The pharmacokinetic (PK) parameters in animal models can help optimize novel candidate drugs prior to human trials. However, due to the complexity of pharmacokinetic experiments, their use is limited in academia. We present a novel surgical rat model for investigation of pharmacokinetic parameters and its use in an anti-obesity drug development program.

MATERIALS AND METHODS

The model uses anesthetized male Wistar rats, a jugular, a femoral catheter, and an insulin pump for peptide infusion. The following pharmacokinetic parameters were measured: metabolic clearance rate (MCR), half-life, and volume of distribution (Vd). Glucagon-like peptide 1 (GLP-1), glucagon (GCG), and exendin-4 (Ex-4) were used to validate the model. The pharmacokinetic parameters of anti-obesity drug candidates X1, X2, and X3 were measured.

RESULTS

GLP-1 had a significantly higher MCR (83.9 ± 14.1 mL/min/kg) compared to GCG (40.7 ± 14.3 mL/min/kg) and Ex-4 (10.1 ± 2.5 mL/min/kg) (p < .01 and p < .001 respectively). Ex-4 had a statistically significant longer half-life (35.1 ± 7.4 min) compared to both GCG (3.2 ± 1.7 min) and GLP-1 (1.2 ± 0.4 min) (p < .01 for both GCG and GLP-1). Ex-4 had a statistically significant higher volume of distribution (429.7 ± 164.9 mL/kg) compared to both GCG (146.8 ± 49.6 mL/kg) and GLP-1 (149.7 ± 53.5 mL/kg) (p < .01 for both GCG and GLP-1). Peptide X3 had a statistically significant longer half-life (21.3 ± 3.5 min) compared to both X1 (3.9 ± 0.4 min) and X2 (16.1 ± 2.8 min) (p < .001 for both X1 and X2).

CONCLUSIONS

We present an affordable and easily accessible platform for the measurement of PK parameters of peptides. This novel surgical rat model produces consistent and reproducible results while minimizing animal use.

Utility of chromogranin A, pancreatic polypeptide, glucagon and gastrin in the diagnosis and follow-up of pancreatic neuroendocrine tumours in multiple endocrine neoplasia type 1 patients

OBJECTIVE

Pancreatic neuroendocrine tumours (PNETs) are the major source of disease-specific mortality in multiple endocrine neoplasia type 1 (MEN1) patients. Chromogranin A (CgA), pancreatic polypeptide (PP), glucagon and gastrin have some diagnostic value in sporadic PNETs, but there is very little evidence for their efficacy in diagnosing PNETs in MEN1 patients.

DESIGN

We performed a retrospective chart review of the existing MEN1 database in our institution.

PATIENTS

One hundred and thirteen patients were eligible for diagnostic value analysis of tumour markers. Patients were excluded if measurement of tumour markers was missing, either 3 months prior to PNET diagnosis (PNET patients) or prior to abdominal imaging (non-PNET patients).

MEASUREMENTS

Clinicopathologic characteristics and of tumour marker measurements were analysed.

RESULTS

Of 293 confirmed MEN1 cases, 55 PNETs and 58 non-PNETs met inclusion criteria. The area under the curve (AUC) for CgA, PP, glucagon and gastrin in MEN1 cases was 59·5%, 64·1%, 77·0% and 75·9%, respectively. The AUC for the combination of CgA, PP and gastrin was 59·6%. PP, but not CgA, glucagon or gastrin was significantly associated with both age and PNET functional status (P = 0·0485 and 0·0188, respectively). No markers were significantly associated with sex, PNET size, tumour number, tumour location, American Joint Committee on Cancer (AJCC) stage, presence of lymph node metastasis, lymphovascular invasion or overall survival. CgA values were not significantly lower following PNET resection than pre-operatively (P = 0·554).

CONCLUSIONS

The value of blood markers for diagnosing PNETs in MEN1 patients is relatively low, even when used in combination.

Proglucagon-Derived Peptides Do Not Significantly Affect Acute Exocrine Pancreas in Rats

OBJECTIVES

Reports have suggested a link between treatment with glucagon-like peptide 1 (GLP-1) analogs and an increased risk of pancreatitis. Oxyntomodulin, a dual agonist of both GLP-1 and glucagon receptors, is currently being investigated as a potential antiobesity therapy, but little is known about its pancreatic safety. The aim of the study was to investigate the acute effect of oxyntomodulin and other proglucagon-derived peptides on the rat exocrine pancreas.

METHODS

Glucagon-like peptide 1, oxyntomodulin, glucagon, and exendin-4 were infused into anesthetized rats to measure plasma amylase concentration changes. In addition, the effect of each peptide on both amylase release and proliferation in rat pancreatic acinar (AR42J) and primary isolated ductal cells was determined.

RESULTS

Plasma amylase did not increase postpeptide infusion, compared with vehicle and cholecystokinin; however, oxyntomodulin inhibited plasma amylase when coadministered with cholecystokinin. None of the peptides caused a significant increase in proliferation rate or amylase secretion from acinar and ductal cells.

CONCLUSIONS

The investigated peptides do not have an acute effect on the exocrine pancreas with regard to proliferation and plasma amylase, when administered individually. Oxyntomodulin seems to be a potent inhibitor of amylase release, potentially making it a safer antiobesity agent regarding pancreatitis, compared with GLP-1 agonists.

Clinical Features, Treatments, and Outcomes of Patients with Thymic Carcinoids and Multiple Endocrine Neoplasia Type 1 Syndrome at MD Anderson Cancer Center

Thymic carcinoids are rare neuroendocrine tumors that occur in 1-5 % of patients with multiple endocrine neoplasia type 1 (MEN1) and are a major cause of morbidity and mortality. The few published reports associate these tumors with male sex and smoking. Our objective was to describe cases of these tumors treated at our institution. We performed a retrospective chart review of all patients diagnosed with MEN1 at our tertiary referral center from 1980 to 2014. Patients with a histopathologic, fine-needle aspiration, or clinical diagnosis of a thymic carcinoid were included. Two hundred ninety-one patients fulfilled the criteria for a diagnosis of MEN1. Clinicopathologic characteristics, MEN1 genetic testing results, treatments, and survival rates were analyzed. Nine patients had a thymic carcinoid, six men (67 %) and three women (33 %). Six patients were non-smokers (67 %). Two patients had synchronous (22 %) and eight patients (89 %) had metachronous distant metastasis. The 10-year overall survival rate was 45 % (lower 95 % upper 95 % CI 20-100 %). The 10-year disease-free survival rate was 42 % (lower 95 % upper 95 % CI 15-100 %). Five patients had MEN1 genetic testing, and the genotypes of affected individuals were p.W341X, c.275_286delGCTTCACCGCCC, p.R98X, c.1350+(1_11)del11, and partial duplication of exons 9 and 10. A higher percentage of MEN1-related thymic carcinoids can occur in women and in non-smokers than previously reported. Both novel and known mutations were present in our cohort. Eighty nine percent of patients developed a metachronous metastasis from the thymic carcinoid. Patients with MEN1 and thymic carcinoids should be followed closely.

Do flow volume loops alter surgical management in patients with a goitre?

INTRODUCTION

Flow volume loops (FVLs) are considered part of the workup of patients with thyroid enlargement presenting to the endocrinology clinic. They are used to detect upper airway obstruction (UAO) secondary to tracheal compression (TC) from a goitre. Surgical assessment in contrast tends to focus on clinical evaluation supplemented when required by imaging. The aim of this study was to investigate whether FVLs influence the decision to operate in patients with a goitre.

METHODS

We identified patients with a goitre referred by the department of endocrinology for FVLs between 2006 and 2011. The results of the FVL were collated, and their impact on patient management was assessed.

RESULTS

Ninety-six patients were referred for FVL. In 38 patients, the indication was specifically to evaluate the effects of a goitre. Of these, 33 were reported as normal. Five FVLs were reported as abnormal (3 suggesting lung pathology and 2 TC). Both patients with TC on FVL presented no CT evidence of TC and underwent surgery due to abnormal cytology. Of the 33 normal FVLs, 7 underwent surgery: 2 for local compression, 4 for abnormal cytology and 1 for Graves' disease. None of the FVLs influenced the decision to operate.

CONCLUSION

FVLs may detect subradiological TC, but rarely influence management in patients with a goitre. In view of this and the cost of £235 per investigation, FVL should be reserved for goitre patients with suspected primary lung pathology, where the distinction between large and small airway compression is likely to influence management.

Learning curve of vessel cannulation in rats using cumulative sum analysis

BACKGROUND

Intravascular access routes are widely used for administering agents or taking blood samples in rodents. Vessel cannulation in rats is a technically challenging procedure with a risk for significant complications. The use of cumulative sum (CUSUM) analysis allows continuous monitoring of the performer's outcomes to evaluate the learning curve for a particular procedure. The aim of the present study was to assess a researcher's learning curve in the cannulation of the jugular and femoral vein in rats using CUSUM analysis.

MATERIALS AND METHODS

A single researcher performed two hundred microsurgical operations between September 2012 and September 2013. The animals (male Wistar rats) were anesthetized with isoflurane whereas the right jugular vein and the left femoral vein were catheterized. Prospective data were collected and analyzed using CUSUM analysis. For the purposes of the study, the rat population was divided in four groups based on the order of studies; group 1 represents the first 50 animals cannulated, group 2 the next batch of 50 animals, and so forth.

RESULTS

The operating times required for cannulation of the jugular vein for groups 1, 2, 3, and 4 were 24.6 ± 4.8, 15.9 ± 2.5, 15.2 ± 3.2, and 15.7 ± 3.3 min, respectively. Group 1's operating time was significantly longer than all the other groups (P < 0.001 compared with all other groups). The operating times for groups 2, 3, and 4 did not differ significantly (P > 0.05). The cannulation of the femoral vein required a mean of 32 ± 5.3 min for group 1, 24.9 ± 5.7 min for group 2, 18.4 ± 4 min for group 3, and 17.2 ± 3.4 min for group 4. The operating time of group 1 was significantly longer when compared with all groups (P < 0.001 for all groups). Group 2 also had a longer operating time than groups 3 and 4 (P < 0.001 compared with both groups). Groups 3 and 4 did not show any statistical significant difference when their operating time was compared (P > 0.05). CUSUM analysis suggested that the number of cases required to achieve the required experience to most effectively cannulate the jugular and femoral vein is approximately 50 and 100 cases, respectively. The adverse effects of the procedure included two unexpected deaths, both of which occurred in group 1 (0.5% in total).

CONCLUSIONS

The authors' experience regarding the learning curve of the cannulation of the femoral and jugular vein in rats from 200 animals operated over a period of 1 y for the evaluation of the pharmacokinetic properties of drug candidates suggests significant experience is required to optimize the operating time required for the procedure.

Rats fed diets with different energy contribution from fat do not differ in adiposity

OBJECTIVE

To determine whether rats reaching the same body mass, having been fed either a low-fat (LFD) or a high-fat diet (HFD), differ in white adipose tissue (WAT) deposition.

METHODS

In experiment 1, 22 Sprague-Dawley rats of the same age were divided into 11 rats with body mass below the batch median and fed a HFD, and 11 above the median and fed a LFD. In experiment 2, 20 Sprague-Dawley rats of the same age and starting body mass were randomised to either a HFD or LFD. When all groups reached similar final body mass, WAT was quantified using magnetic resonance imaging (MRI), dissection, and plasma leptin.

RESULTS

In experiment 1, both groups reached similar final body mass at the same age; in experiment 2 the HFD group reached similar final body mass earlier than the LFD group. There were no significant differences in WAT as assessed by MRI or leptin between the HFD and LFD groups in both experiments. Dissection revealed a trend for higher retroperitoneal and epididymal adiposity in the HFD groups in both experiments.

CONCLUSIONS

We conclude that at similar body mass, adiposity is independent of the macronutrient composition of the feeding regimen used to achieve it.

Systematic review and meta-analysis of retroperitoneoscopic versus laparoscopic adrenalectomy

BACKGROUND

Laparoscopic adrenalectomy (LA) has replaced open adrenalectomy as the standard operation for non-malignant adrenal tumours. Retroperitoneoscopic adrenalectomy (RA) is an increasingly popular alternative minimally invasive approach. Advocates of each technique claim its superiority, but the issue has yet to be resolved and conclusions are complicated by the existence of a lateral (LRA) and true posterior (PRA) RA.

METHODS

A literature search was performed for all comparative studies of RA versus LA. Meta-analysis was performed according to PRISMA guidelines. Odds ratios and standardized mean differences (SMD) were used to compare dichotomous and continuous outcomes respectively.

RESULTS

Twenty-two studies were included, reporting on 1257 LAs, 471 LRAs and 238 PRAs. Both PRA and LRA were associated with a reduced length of hospital stay: SMD - 1·45 (95 per cent confidence interval - 2·76 to - 0·14) and - 0·54 (-1·04 to - 0·03) days respectively compared with LA. Interstudy heterogeneity was present throughout the comparisons of hospital stay. When considering only the two randomized clinical trials (RCTs) there was no statistically significant difference in this outcome. One RCT, however, found a reduction in the median time to convalescence of 2·4 weeks in the LRA group. There were no differences in duration of operation, blood loss, time to ambulation and oral intake, or complication rates between techniques.

CONCLUSION

RA overall has equivalent outcomes to LA but may be associated with a shorter hospital stay.

Measuring the stress of the surgeons in training and use of a novel interventional program to combat it

Purpose

Stress poses a serious risk for training surgeons since their performance and well-being in reflected in patients' health. This study focuses on measuring the stress of training surgeons and at the same time evaluates prospectively the results of an innovative program that uses alternative techniques to combat the effects of stress.

Methods

The study was a pilot randomized controlled trial, with a duration of 6 months. Participants were allocated to a control and an intervention group. Trainees then completed three questionnaires, quality of life, perceived stress scale (PSS) and job content questionnaire serving as a baseline measurement. Only the intervention group used diaphragmatic breathing and progressive muscular relaxation techniques, twice a day, for 20 minutes each, and for a total period of eight weeks. At the end of the study, the same questionnaires were completed again by both groups.

Results

The sample of the study included 28 and 32 trainees in the control and the intervention group, respectively. The Cronbach's α value for the PSS stress-measuring questionnaire was 0.772. The intervention group presented statistically significant lower values of stress (30.50, P < 0.05) in comparison to the control group (27.54).

Conclusion

The medical community, and especially surgeons, have been reluctant up to now to embrace interventional programs that go beyond the traditional use of medication in order to address stress related issues. The positive results and feedback from small studies, such as ours, can provide the driving force for further research that will give us solid, evidence-based, answers.

Minimally invasive parathyroidectomy in patients with previous neck surgery

OBJECTIVE

Previous neck surgery (PNS) in patients with primary hyperparathyroidism (PHP) is considered as a contraindication for minimally invasive parathyroidectomy (MIP). The purpose of our study was to determine the effectiveness of MIP in such patients.

DESIGN

From January 2003 to June 2011, 380 patients with PHP were treated in our department; 42 had had previous neck surgery. Twenty-seven (27/42) were selected to have MIP; the remaining 15 patients had traditional neck explorations. Selection criteria for MIP were unilateral single or two gland disease localized preoperatively with at least two imaging techniques and patient's informed consent. Imaging studies included high resolution neck ultrasound and sestamibi scan in the majority, and CT scan, selective venous sampling and MRI in seven patients. The type of operation done included unilateral approach under local anesthesia (UALA) (22 cases) with one conversion to general anesthesia and minimally invasive parathyroidectomy under general anesthesia (MIPG) (5 cases).

RESULTS

Twenty-six of the 27 patients became normocalcemic after the operation. The patient with persistent hypercalcemia underwent successful parathyroidectomy 8 months later via mesothoracoscopy, since the parathyroid gland was localized correctly but was beyond access via neck. A single adenoma was found in 21 cases and hyperplasia in six. There were no conversions to traditional exploration and no postoperative complications. Mean duration of the procedure and length of stay were similar to MIP in patients without PNS. Mean follow-up of 40 months (4-89 months) did not reveal any recurrence.

CONCLUSION

These results illustrate that MIP is a valuable option in selected patients with PHP and PNS associated with no morbidity (0%), high biochemical cure rate (96.3% in this series) and rapid recovery, while it also substantially lowers the cost of the procedure. Preoperative localization with two or more agreeing imaging techniques eliminates the need for intraoperative sestamibi or qPTH test.