Megan K. Applewhite

Normohormonal primary hyperparathyroidism is a distinct form of primary hyperparathyroidism

Background. Normohormonal primary hyperparathyroidism presents diagnostic and intraoperative challenges, and current literature is conflicting about management. We aim to better define normohormonal primary hyperparathyroidism in order to improve the care for these patients. Methods. In the study, 516 consecutive patients undergoing parathyroidectomy for primary hyperparathyroidism were divided into 2 groups: classic primary hyperparathyroidism (classic primary hyperparathyroidism, increased serum levels of calcium, and parathyroid hormone) and normohormonal primary hyperparathyroidism (hypercalcemia, normal serum levels of parathyroid hormone). We evaluated inter‐group differences in presentation, gland weight, pathology, and complications. Results. The normohormonal primary hyperparathyroidism group was comprised of 116 (22.5%) patients. Mean serum levels of parathyroid hormone and calcium were 62.1 pg/mL ± 10.1 and 10.6 mg/dL ± 0.63 in normohormonal primary hyperparathyroidism, and 142 ± 89.0pg/mL and 11.0 ± 0.88 (both P < .01) for classic primary hyperparathyroidism. Nephrolithiasis was more common in normohormonal primary hyperparathyroidism. Multigland hyperplasia was more common in normohormonal primary hyperparathyroidism 23 (19.8%) vs 44 (11%; P = .04). Concordant imaging studies were less likely in normohormonal primary hyperparathyroidism (82 [73.2%] vs 337 [87.1%; P < .01]), had a lesser total gland weight (531.8 mg ± 680.0 vs 1,039.6 mg ± 1,237.3; P < .01), and lesser 2‐week parathyroid hormone (32.5 pg/mL ± 18.95 vs 41.0 pg/mL ± 27.8; P = .01). There was no difference in hypoparathyroidism (parathyroid hormone <15 pg/mL; P = .93) at 2 weeks postoperatively. Conclusion. Normohormonal primary hyperparathyroidism represents 22.5% of our primary hyperparathyroidism population, which is greater than reported previously. It is a distinct disease process from classic primary hyperparathyroidism in presentation, imaging, and operative findings. More hyperplasia and a lesser gland weight make it challenging to resect the ideal amount of tissue. Studies with long‐term follow‐up are needed to determine optimal operative management.

Rates of secondary hyperparathyroidism after bypass operation for super-morbid obesity: An overlooked phenomenon

Background. With over 110,000 bariatric operations performed in the United States annually, it is important to understand the biochemical abnormalities causing endocrine dysfunction associated with these procedures. Here we compare 2 malabsorptive procedures, duodenal switch and Roux‐en‐Y gastric bypass, to determine the role malabsorption plays in secondary hyperparathyroidism in this population. Methods. Data from all super‐obese patients undergoing duodenal switch or Roux‐en‐Y gastric bypass between August 2002 and October 2005 were prospectively collected. Postoperatively, all patients received 1,200 mg of calcium citrate and 1,000 IU vitamin D3 per American Society for Metabolic and Bariatric Surgery guidelines. Beginning in 2007, duodenal switch patients were instructed to add daily vitamin D3 10,000 IU. Statistical analyses included Student t test, multivariate, and univariate logistic regression. Results. Of 283 patients with a body mass index ≥50, 170 (60.1%) underwent duodenal switch, while 113 (39.9%) underwent Roux‐en‐Y gastric bypass. Of 132 (46.6%) patients with secondary hyperparathyroidism, 101 (59.4%) had undergone duodenal switch and 31 (27.4%) had undergone Roux‐en‐Y gastric bypass. Symptoms were more common in the duodenal switch group (33 patients [19.4%]) than Roux‐en‐Y gastric bypass (11 patients [9.7%]). Multivariate logistic regression demonstrated that the extent of bypass and duration of follow‐up were the only 2 independent predictive risk factors for developing secondary hyperparathyroidism. Although vitamin D levels improved with increased vitamin D3 supplementation in 2007, rates of secondary hyperparathyroidism increased. Conclusion. Despite routine postoperative calcium and vitamin D3 supplementation, secondary hyperparathyroidism is common after Roux‐en‐Y gastric bypass and duodenal switch. The degree of iatrogenic malabsorption correlates with the incidence of secondary hyperparathyroidism. These rates suggest current supplementation guidelines are not sufficient in preventing secondary hyperparathyroidism. Further work is needed to better define the sequelae of long‐term hyperparathyroidism.

Is ‘Quality Science’ Human Subjects Research?

Physicians have an ethical obligation to their patients, institutions, and community to provide the highest quality of care possible. In the past 15 years, beginning with the Institute of Medicine’s To Err is Human report (Kohn et al. To err is human: building a safer health system. Washington, DC: National Academies Press, 2000), Quality Improvement (QI) in surgery has been prioritized by national organizations, including the Centers for Medicare & Medicaid Services, the Center for Disease Control, the American College of Surgeons, and the Accreditation Council for Graduate Medical Education (ACGME). The aim of QI projects is to evaluate the quality of perioperative surgical care and design projects that modify systems and behavior within individual institutions to produce better patient outcomes.