Parathyroid imaging: technique and role in the preoperative evaluation of primary hyperparathyroidism

OBJECTIVE: This article discusses the commonly used techniques for imaging the parathyroid glands and their role in the preoperative evaluation of patients with primary hyperparathyroidism. CONCLUSION: The importance of sonography and sestamibi scintigraphy in the preoperative evaluation of patients with primary hyperthyroidism has increased with the adoption of minimally invasive parathyroidectomy techniques at most medical centers. When the results of these studies are concordant, the cure rates of minimally invasive surgery equal those of traditional bilateral neck exploration.     

Underuse of Oral Anticoagulants in Atrial Fibrillation: A Systematic Review

Background

Atrial fibrillation is associated with substantial mortality and morbidity from stroke and thromboembolism. Despite an efficacious oral anticoagulation therapy (warfarin), atrial fibrillation patients at high risk for stroke are often under-treated. This systematic review compares current treatment practices for stroke prevention in atrial fibrillation with published guidelines.

Methods

Literature searches (1997-2008) identified 98 studies concerning current treatment practices for stroke prevention in atrial fibrillation. The percentage of patients eligible for oral anticoagulation due to elevated stroke risk was compared with the percentage treated. Under-treatment was defined as treatment of <70% of high-risk patients.

Results

Of 54 studies that reported stroke risk levels and the percentage of patients treated, most showed underuse of oral anticoagulants for high-risk patients. From 29 studies of patients with prior stroke/transient ischemic attack who should all receive oral anticoagulation according to published guidelines, 25 studies reported under-treatment, with 21 of 29 studies reporting oral anticoagulation treatment levels below 60% (range 19%-81.3%). Subjects with a CHADS₂ (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score ≥2 also were suboptimally treated, with 7 of 9 studies reporting treatment levels below 70% (range 39%-92.3%). Studies (21 of 54) using other stroke risk stratification schemes differ in the criteria they use to designate patients as “high risk,” such that direct comparison is not possible.

Conclusions

This systematic review demonstrates the underuse of oral anticoagulation therapy for real-world atrial fibrillation patients with an elevated risk of stroke, highlighting the need for improved therapies for stroke prevention in atrial fibrillation.     

Cost-effectiveness of pneumococcal polysaccharide vaccination in adults: A systematic review of conclusions and assumptions

Streptococcus pneumoniae infections in adults are associated with substantial morbidity, mortality, and costs. A literature review was conducted to identify strengths and limitations of the cost-effectiveness of pneumococcal polysaccharide vaccine studies. A comparative analysis of the impact of model parameters on cost-effectiveness ratios was complemented by systematic assessment of the studies. We identified 11 economic evaluations of pneumococcal polysaccharide vaccine (PPV-23) in adults. In general, all 11 studies found that vaccination with PPV-23 is a cost-effective, and in some cases a cost-saving strategy for the prevention of invasive pneumococcal disease (IPD). The systematic assessment indicated that the results of the cost-effectiveness studies of PPV-23 are influenced by the values applied to vaccine efficacy, IPD incidence and case-fatality.     

Parathyroid lipoadenomas and lipohyperplasias: clinicopathologic correlations

Parathyroid lipoadenomas and lipohyperplasias are rare histologic variants with both an increase in stromal fat and parenchyma. We report the most comprehensive single institution series of lipoadenomas and lipohyperplasias to date and review the literature. Eight lipoadenomas and 3 lipohyperplasias (27 y period) were reviewed. The mean age was 60.3 years (range: 50 to 77 y) with a female predilection (1.75:1). The most common symptoms on presentation were fatigue (55.6%) and bone/joint pain (44.4%). Only 1 patient was euparathyroid. Ultrasound localized lipoadenomas in 50% of tested cases whereas sestamibi was successful in 71.4%. Despite increased stromal fat (median: 50%), the weight and the appearance of large, occasionally nodular expansions of parathyroid parenchyma within the fatty stroma distinguished lipoadenomas and lipohyperplasias from normal parathyroid tissue; none of the cases were misclassified as normal on frozen section. Mean weight for lipoadenomas was 1553 mg (range: 173 to 4587 mg), whereas the mean weight for lipohyperplasia glands was 389.1 mg. Variant morphologies included follicular patterned, oxyphil predominant, and thymic elements (thymolipoadenoma). In 1 lipohyperplasia case, not all glands were involved. Oil Red O stains showed decreased intracytoplasmic lipid in most cases. Median follow-up was 9.2 months (range: <1 to 51 mo). Only 1 lipohyperplasia patient had persistent hypercalcemia, but was asymptomatic. Lipoadenomas and lipohyperplasias are clinically similar and as histologically diverse as their conventional counterparts. Lipoadenomas are more difficult to localize preoperatively by imaging. Despite the potential difficulty at frozen section, accurate weight documentation and recognition of key histologic features diminish this challenge.     

Can a Lightbulb Sestamibi SPECT Accurately Predict Single-Gland Disease in Sporadic Primary Hyperparathyroidism?

Background Technetium-99m sestamibi scintigraphy with single photon emission computed tomography (SPECT) is widely used to guide minimally invasive exploration in patients with sporadic primary hyperparathyroidism (SPH), although its sensitivity in multiglandular disease is limited. We examined the incidence of missed multiglandular disease and associated anatomic findings when sestamibi SPECT was positive for a single intense focus of delayed tracer uptake, termed a lightbulb scan (LBS). Methods Prospectively entered data from 764 patients with SPH treated with initial parathyroid exploration from March 5, 2000, to December 31, 2006, were reviewed. A single radiologist performed blinded interpretation of 585 available sestamibi SPECT images, classifying 167 (28.5%) patients with a LBS. Clinical findings were compared among LBS patients with a single adenoma (true positive) and LBS patients with multiglandular disease (false negative). Results One hundred fifty of 167 (89.8%) LBS patients had a single adenoma and 3 (1.8%) had carcinoma. Multiglandular disease was anatomically present in 14 of 167 (8.4%) LBS patients compared with 60 of 418 (15.6%) non-LBS patients (p = 0.05). Parathyroid hyperplasia occurred less frequently in LBS patients [5/167 (3%)] compared with non-LBS patients [36/418 (8.6%)], (p = 0.02), while double adenomas occurred equally often in LBS patients [9/167 (5.4%)] compared with non-LBS patients [24/418 (5.7%)], (p = 0.87). Double adenomas in LBS patients were more likely ipsilateral (7/9, p = 0.005) and left-sided (7/7, p = 0.008). LBS patients with multiglandular disease were more likely to have a history of neck irradiation, prior neck exploration, and concomitant thyroid pathology. Conclusions In patients with SPH, sestamibi SPECT studies show a single bright focus of uptake in only 29% of patients. LBS findings do not exclude multiglandular disease. To avoid unacceptable rates of failure at initial parathyroid exploration, the expert surgeon should use validated adjuncts such as intraoperative PTH monitoring or four-gland exploration.     

A technique for removal of broken cannulated tricortical syndesmotic screws

Breakage rates of tricortical syndesmotic screws after weight bearing range from 10% to 29%. Removal of the portion of the broken screw buried within the tibia often proves quite difficult. We report a new technique to remove a broken cannulated syndesmotic screw. This technique is simple, time saving, and less traumatic than previously reported methods of broken syndesmotic screw removal.     

Establishing methodological rigour in international qualitative nursing research: a case study from Ghana

BACKGROUND: Attention to rigour, from the identification of the problem to the dissemination of the findings, is essential in all qualitative research. In this paper, research carried out in Ghana in 1999 is used to highlight methodological issues in relation to rigour in international qualitative nursing research. AIM: The purpose of this paper is to review the literature in relation to rigour in qualitative research, highlight the methodological decisions enhancing rigour during this research project, and describe the criteria used to assess rigour during the research process. DESIGN: A participatory action research design was used to explore the cultural, social, economic, and political factors that influenced Ghanaian women's vulnerability to HIV infection. Collaboration with participants and partnerships with key professionals were integral to the design of the study. FINDINGS: Participatory action research provided a flexible, socially, and culturally adaptable framework to guide this international research project. Prior to the initiation of international research it was essential to establish the relevance and feasibility of the proposed project. This international research project posed additional methodological challenges to the establishment of rigour. Patience, flexibility and sensitivity were required of the researcher to overcome these challenges. CONCLUSION: Collaboration with participants and with culture-specific 'experts' may be key to culturally competent scholarship, particularly in unfamiliar settings.