Association of symptomatic gallstones and primary hyperparathyroidism: a propensity score-matched analysis

If the prevalence of primary hyperparathyroidism (PHPT) in patients with symptomatic gallstones is higher than that in the general population, PHPT screening could reveal important clinical implications. We observed that the prevalence of PHPT in these patients was higher compared to that of healthy matched controls.

The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Cost-effectiveness of intraoperative nerve monitoring in avoidance of bilateral recurrent laryngeal nerve injury in patients undergoing total thyroidectomy

Background

Intraoperative nerve monitoring (IONM) provides dynamic neural information and is recommended for high-risk thyroid surgery. In this analysis, the cost-effectiveness of IONM in preventing bilateral recurrent laryngeal nerve (RLN) injury was investigated.

Methods

A Markov chain model was constructed based on IONM use. The base-case patient was defined as a 40-year-old woman presenting with a 4·1-cm left-sided papillary thyroid cancer who developed RLN injury with loss of monitoring signal during planned bilateral thyroidectomy. It was hypothesized that, if the surgeon had used IONM, the RLN injury would have been detected and the operation would have been concluded as a thyroid lobectomy to avoid the risk of contralateral RLN injury. Cost in US dollars was converted to euros; probabilities and utility scores were identified from the literature and government resources. Length of follow-up was set as 20 years, and willingness-to-pay (WTP) as €38 000 (US $50 000) per quality-adjusted life-year (QALY).

Results

At the end of year 20, the not using IONM strategy accrued €163 995·40 (US $215 783·43) and an effectiveness of 14·15 QALYs, whereas use of the IONM strategy accrued €170 283·68 (US $224 057·48) and an effectiveness of 14·33 QALYs. The incremental cost–effectiveness ratio, comparing use versus no use of IONM, was €35 285·26 (US $46 427·97) per QALY, which is below the proposed WTP, indicating that IONM is the preferred and cost-effective management plan. A Monte Carlo simulation test that considered variability of the main study factors in a hypothetical sample of 10 000 patients showed IONM to be the preferred strategy in 85·8 per cent of the population.

Conclusion

Use of IONM is cost-effective in patients undergoing bilateral thyroid surgery.

Endpoints for screening thyroid cancer in the Republic of Korea: thyroid specialists' perspectives

Cancer screening is aimed primarily at reducing deaths from the specific cancer. Thyroid-specific cancer mortality may be the most ambitious endpoint for obtaining estimates of screening effect. Numerous observations have accumulated over the years, indicating that thyroid cancer mortality endpoint has been difficult to study and is confounded by population heterogeneity, provision of randomization, and requirement of large cohorts with sufficiently long follow-up due to the excellent prognosis of the cancer. Accordingly, it may be important to reconsider how to best measure thyroid cancer screening efficacy. Recommendations against thyroid cancer screening should be based upon trials designed to evaluate its effectiveness not only in significant reduction in cancer mortality, but also of other distinct endpoints. It is desirable to evaluate derivative endpoints that can reliably predict reductions in mortality. The term "derivative" means a variable that is related to the true endpoint and is likely to be observable before the primary endpoint. Derivative endpoints may include thyroid cancer incidence, the proportion of early-stage tumors detected, more treatable stage, the identification of small tumors (to maintain in observation), decrease in the number of people who develop metastatic disease, the increased chance of lesser extent surgery, and the application of minimally invasive approaches, as well as no need for lifelong thyroid replacement therapy, a consistent follow-up, low-dose or no RAI administration and risk factor assessments where case findings should be continuous. The Korean guidelines for thyroid cancer national-level screening were published by a relevant group of multidisciplinary thyroid experts. It was concluded that the evidence is insufficient to balance the benefits and harms of thyroid cancer screening. However, the paper seems to raise the necessary investments in future research and demand a complete analysis for derivative endpoints, and offer screening participants with complete information necessary to make decisions that will provide them with the most value when a small thyroid cancer is screen-identified.

Recurrent laryngeal nerve injury in video-assisted thyroidectomy: lessons learned from neuromonitoring

INTRODUCTION

The objective of the study was to assess the mechanism of recurrent laryngeal nerve (RLN) injury during video-assisted thyroidectomy (VAT).

METHODS

The study examined 201 nerves at risk (NAR). VAT with laryngeal neuromonitoring (LNM) was outlined according to this scheme: (a) preparation of the operative space; (b) vagal nerve stimulation (V1); (c) ligature of the superior thyroid vessels; (d) visualization, stimulation (R1), and dissection of the RLN; (e) extraction of the lobe; (f) resection of the thyroid lobe; (g) final hemostasis; (h) verification of the electrical integrity of the RLN (V2, R2). The site, cause, and circumstance of nerve injury were elucidated with the application of LNM. Laryngeal nerve injuries were classified into type 1 injury (segmental) and 2 (diffuse).

RESULTS

Fourteen nerves (6.9 %) experienced loss of R2 and V2 signals. 80 percent of lesions occurred in the distal 1 cm of the course of the RLN. The incidence of type 1 and 2 injuries was 71 and 29 % respectively. The mechanisms of injury were traction (70 %) and thermal (30 %). Traction lesions were created during the extraction of the lobe from the mini-incision [point (e)]. Thermal injury occurred during energy-based device use in (f) and (g) circumstances.

CONCLUSIONS

RLN palsy still occurs with routine endoscopic identification of the nerve, even combined with LNM. LNM has the advantage of elucidating the mechanism of RLN injury. Traction and thermal RLN injuries are the most frequent lesions in VAT.

Implementation of systematic neuromonitoring training for thyroid surgery

Neural monitoring is increasingly applied to thyroid surgery and yet few surgeons have received formal training in intraoperative neuromonitoring (IONM). Standardized application of neural monitoring is an expected outcome of formal training programs in IONM. This study was designed to document a systematic training course that focuses on standardized state-of-art IONM knowledge. Seventeen 1-day courses were organized by the Department of Surgical Sciences, University of Insubria Medical School (Varese-Como, Italy), between 2009-2010. The course included didactic and practical training sessions. Some specific steps and checklist identified for courses included: knowledge of IONM technology and troubleshooting algorithms; IONM anesthetic perspectives, standards of IONM equipment set up and technique. A total of 75 trainees completed a questionnaire after completion of the respective courses. Questions probed demographic data, operative IONM experience and evaluation of course content. Data gathered showed that 97% of participants had no prior experience with the standardized approach of IONM technique (i.e. stimulation of the vagal nerve). The most useful parts of the course were judged to be (a) algorithms for perioperative IONM problem solving (30%), (b) live surgery with hands-on training (25%), (c) standardization of IONM technique (25%), and (d) IONM equipment set-up (20%). Poor reimbursement for hospital thyroid procedures is the main reason of limitation of IONM technology. The course offered participants novel knowledge and training and gave participants a systematic and standard approach to IONM technique.

[Laryngoscopy in patients undergoing thyroidectomy]

In a group of 365 patients undergoing thyroidectomy, the group of 21 patients with invasive thyroid malignancy was compared with 344 patients with benign thyroid disease or noninvasive cancers. It was shown that the method of indirect laryngoscopic examination was a simple and efficient method for detection of vocal cord paralysis and for the assessment of involvement of the surrounding tissues by the tumor. For the preoperative diagnosis of invasion of the recurrent nerve area such criteria as changed voice, results of CT and MRT were shown to be insufficiently reliable.

Physician experience with an optical image guidance system for sinus surgery

OBJECTIVES/HYPOTHESIS

Intraoperative guidance systems have been developed which use infrared tracking technology to assist with anatomical localization during sinus surgery. Although the introduction of this technology is intended to increase the safety and efficacy of sinus surgery, little is known about its actual impact in the clinical setting. The objective of this report was to study the application and utilization of an image guidance system shared by multiple sinus surgeons in a specialty hospital.

STUDY DESIGN

Combined prospective case study and retrospective analysis of physician surveys.

METHODS

An optical-based image guidance system (LandmarX, Xomed, Inc., Jacksonville, FL) was used by 34 physicians to perform 754 sinonasal surgeries over a 2.5-year period at Massachusetts Eye and Ear Infirmary. In 19 cases, system registration was repeated during surgery to measure the effect of fiducial placement on system accuracy.

RESULTS

The measured accuracy of anatomical localization at the start of surgery (mean value, 1.69 +/- 0.38 mm) was comparable to the perceived accuracy of 1 to 3 mm that was reported by 79% of surgeons surveyed. Operating room time (mean period, 130.6 +/- 41.1 min) correlated with the surgical procedure performed (P < .05), but not with the disease stage or revision rate. According to a majority of surgeons, use of the image guidance equipment increased operating room time by 15 to 30 minutes during initial cases and by 5 to 15 minutes once experience with the equipment had been acquired. More than 90% of surgeons anticipated their continued use of the image guidance equipment for sinus surgery at a similar or greater level in the future.

CONCLUSION

An optical-based image guidance system can be successfully integrated into a multisurgeon operating room environment. Use of the system provides accurate anatomical localization during sinus surgery and results in a relatively high level of physician satisfaction.

Medullary carcinoma of the thyroid

Medullary thyroid cancer (MTC) is a distinct C-cell tumor of the thyroid. We review the oncogenesis and management of both sporadic tumors and those tumors arising as part of specific inherited syndromes. The RET proto-oncogene plays a role in the development of inherited forms of MTC and has become important in the clinical management of patients and their families. The recognition of the high rate of regional nodal involvement has led to lymphadenectomy being strongly considered for patients undergoing thyroidectomy for MTC.

Microscopic detection of occult malignancy in the adult tonsil

Microscopic evaluation of all adult tonsillar specimens has been considered essential despite the low incidence of unsuspected pathologic conditions. We evaluate whether routine histologic examination of clinically benign adult tonsillar specimens is indicated. We retrospectively reviewed pathology results from all tonsillectomies performed on patients ages 18 years or older at our institution from 1989 through 1996. Three groups were created on the basis of indications for tonsillectomy: (1) routine tonsillectomies for benign disease, (2) asymmetric tonsils, and (3) search for unknown primary lesions. Demographic data and pathologic findings in each group were analyzed. In 1280 tonsillectomies performed for benign disease there were no malignancies (0%) and 32 cases (2.50%) with clinically unsuspected benign pathologic conditions. In 31 cases of tonsillar asymmetry, two cases with malignant lymphoma (6.5%) and three cases with benign pathology (9.7%) were identified. In nine patients with squamous cell carcinoma metastatic to the neck, two occult primary lesions were identified in the ipsilateral tonsil. Our results suggest that histologic evaluation of adult tonsils removed for benign disease may be clinically unnecessary. The elimination of microscopic examination of tonsils removed from patients whose clinical presentation is entirely consistent with benign disease poses minimal risk of missing clinically significant pathologic conditions. Substantial costs for negative examinations may be avoided.

Pulsatile administration enhances the effect and reduces the dose of oxytocin required for induction of labor

Pulsatile administration of oxytocin was compared with continuous infusion of oxytocin for induction of labor in pregnant rats. The dosages consisted of intravenous injections of 0, 2.5, and 5 mU oxytocin every 10 minutes and intravenous infusion of 1 mU/minute of oxytocin in 0.9% sodium chloride. These doses are within the range of endogenously secreted pulses. All treatments began on day 22 at 2 p.m. and continued for 8 hours. Pulsatile administration resulted in a marked reduction in the dose of oxytocin required to induce labor. Using 5 mU pulses, birth was induced with 18.4%, and using 2.5 mU pulses, with 24% of the dose needed using continuous infusion. Parturition was advanced by 12 hours on the average by oxytocin treatment, but no significant differences were observed between the various oxytocin dosage regimens in this regard or in regard to gestation length, induction-delivery interval, duration of delivery, or the proportion of living or dead pups. Significantly more uterine activity was induced with each mU of oxytocin using pulsatile administration than using continuous infusion. There was no evidence for down-regulation of oxytocin receptors during a continuous infusion of oxytocin. We postulate that the greater efficacy of oxytocin pulses to induce uterine activity and delivery in comparison to continuous infusions is due to a more effective stimulation of prostaglandin F2 alpha release from the decidua. The amount of oxytocin needed for induction of labor with 2.5 mU pulses was similar to the decrease in neurohypophyseal oxytocin content during the first stage of spontaneous labor, and uterine activity elicited was also similar to that observed during spontaneous labor.(ABSTRACT TRUNCATED AT 250 WORDS)