Hewlett, Jennifer R

Abstract Disclosure: J.R. Hewlett: None. J.G. Sfeir: None. R.A. Wermers: None. J.J. Schmitz: None. Percutaneous ethanol ablation (PEA) is a non-surgical technique used in the management of hyperparathyroidism (HPT) since the 1980s. Previously published cohorts are small and/or focused on patients with primary hyperparathyroidism (PHPT) in the setting of multiple endocrine neoplasia type 1 (MEN1). New randomized controlled trial data suggests similar response rates between parathyroidectomy and PEA (98.5% vs 91.1%) for uniglandular disease, and a previously published cohort of PEA in patients with MEN1 and recurrent multiglandular PHPT at our institution reported post-PEA normocalcemia in 74.5% of patients. This retrospective cohort study examined the treatment response to PEA in those with PHPT (including MEN1) and tertiary HPT (THPT) at a single institution between 1997-2023. Those with secondary hyperparathyroidism or eucalcemic PHPT were excluded. The primary outcome was a serum calcium ≤10.1 mg/dL at 3-6 months and secondary outcomes included number and volume of ethanol injections, time to recurrence of HPT, and complications of PEA. A total of 83 patients were included. Most were women (62.7%) and the median age at diagnosis of HPT was 40 years. The majority had PHPT (90.4%), and many (86.7%) had previously undergone surgery. The most common indications for PEA were risk for hypoparathyroidism with additional surgery (72.3%) poor surgical candidacy (16.9%), and patient preference (8.4%). The mean calcium was 10.7 mg/dL (95% CI 10.56-10.85) and the mean PTH was 164 pg/mL (95% CI 120.6-208.3) prior to PEA. The mean number of ethanol injections was 3.0 (95% CI 2.6 – 3.4) and the cumulative volume of ethanol was 1.2 mL (95% CI 1.0-1.4). At 3-6 months, 68.3% of treated patients had calcium ≤10.1 mg/dL with a mean value of 9.4 mg/dL (95% CI 9.1-9.6). Of those, 42% did not have recurrence at most recent follow-up. Of those with recurrence, a post-PEA calcium ≤10.1 mg/dL at 3-6 months was associated with a longer time to recurrence than those without (36.9 months versus 3.75 months; P=0.0009). There was no significant difference between the number of times (P=0.56) or the volume (P=0.41) of ethanol injected between those with calcium of ≤10.1 mg/dL at 3-6 months and those without. Hypocalcemia was observed in 8 (9.6%; transient in 75%), hypoparathyroidism in 3 (3.6%; transient in 66.7%), laryngeal nerve injury in 2 (2.4%; transient in 50%), and hoarseness in 9 (10.8%; transient in 100%) patients. This is the largest North American cohort of patients who received PEA for HPT and represents a broader review of HPT than previously published. Our rate of post-PEA eucalcemia is lower than previously reported, however this cohort was complex with a high proportion of multiglandular disease (80.7%), MEN1 (39.8%) and prior surgeries (mean 1.7 per person; 95% CI 1.5-1.9). PEA remains a safe and effective treatment for patients with recurrent HPT, especially those at high risk of post-surgical hypoparathyroidism. Presentation: Monday, July 14, 2025

Abstract Bisphosphonates frequently provoke a cytokine-driven acute clinical response (ACR) characterized by fever, chills, arthralgias, and myalgias. More rarely, an association between aminobisphosphonates, such as alendronate and zoledronic acid, and rheumatologic and/or immune-mediated syndromes (RIMS) has been described. Herein we report 2 patients, one with a prior history of rheumatic disease and one without, who developed giant cell arteritis meeting the American College of Rheumatology 2022 criteria following zoledronic acid infusion. We subsequently review existing mechanistic and clinical literature supporting this link. The duration of symptoms and elevation of inflammatory markers may serve as indicators for differentiating between the more common ACR and less frequent but potentially morbid RIMS. Although the benefit of bisphosphonates will outweigh the risk of RIMS for most patients with high fracture risk, clinicians should be aware of this phenomenon to assist earlier diagnosis and treatment in affected individuals.