Calciphylaxis after parathyroidectomy

A 60-year-old African American man with end stage renal disease on hemodialysis (HD) for the past 2.5 years developed severe hyperparathyroidism. Other past medical history included atrial fibrillation, type II diabetes mellitus, hypertension, gout, pericardial effusion needing pericardial window, deep vein thrombosis, mitral insufficiency, and cardiomyopathy with implantable cardioversion device placement. His parathyroid hormone (PTH) level peaked at 4,191 pg/mL despite being on cinacalcet, sevelamer, and paricalcitol. He underwent a subtotal parathyroidectomy in January 2015, after which his PTH levels dropped to 184 pg/mL. Approximately 4 weeks later he developed extensive, painful necrotic skin lesions in both his lower extremities and buttocks, suggestive of calciphylaxis which was confirmed by tissue biopsy. The patient was treated with elaborate wound care, wound debridements, increased dialysis dose, and IV sodium thiosulfate (STS) during hemodialysis. Besides STS, he was treated with narcotics, gabapentin, topical lidocaine on intact skin, and oral steroids for pain control. Even though his lesions improved initially, he deteriorated due to recurrent sepsis, respiratory failure, and prolonged hospitalization which culminated in stopping dialysis before he passed away. Calciphylaxis, or calcific uremic arteriolopathy, is a life-threatening complication of end stage renal disease. Treatment of this condition is multidisciplinary which includes elaborate wound care, increasing dialysis dose, and discontinuing vitamin D supplements and calcium containing phosphate binders. Even though STS has been recommended off-label, several studies have shown promising results with resolution of lesions. Thus, sodium thiosulfate has become the mainstay of treatment. Parathyroidectomy is a recommended modality of treatment in those with high PTH levels. Our case was unique in that calciphylaxis developed after subtotal parathyroidectomy. We believe that this is due to a decreased PTH level and decreasing bone turnover which resulted in more circulating calcium facilitating vascular and soft tissue calcification. The exact mechanism of developing calciphylaxis after parathyroidectomy is unknown. Even though parathyroidectomy is an effective treatment for calciphylaxis, clinicians should be aware that it can rarely present after parathyroidectomy.