Refractory Hypocalcemia Following Total Thyroidectomy in an Adult Patient With Bariatric Surgery

Obesity poses a global health challenge with significant individual and societal impacts. Bariatric surgery, including Roux-en-Y gastric bypass (RYGB) and biliopancreatic diversion/duodenal switch (BPD/DS), is effective for long-term weight management but can lead to serious nutritional deficiencies, particularly hypocalcemia. This report presents the rare case of a 35-year-old woman with severe, recurrent hypocalcemia following BPD/DS surgery, complicated by iatrogenic hypoparathyroidism from prior thyroidectomy. Despite aggressive oral and intravenous calcium and vitamin D supplementation, the patient's hypocalcemia remained refractory, necessitating multiple hospitalizations. Laboratory studies confirmed severe hypocalcemia, low parathyroid hormone (PTH), and deficiencies in fat-soluble vitamins, complicating her clinical management. As conventional treatments failed, the patient underwent surgical revision from BPD/DS to RYGB anatomy, aimed at improving calcium absorption by restoring functional small bowel length. Postoperatively, her serum calcium levels normalized, and she was successfully discharged on oral calcium supplementation, with stable calcium levels at follow-up. This case underscores the challenges of managing hypocalcemia in patients with BPD/DS anatomy and hypoparathyroidism. The greater malabsorption associated with BPD/DS can severely impair calcium absorption, leading to refractory hypocalcemia. This report is the first documented case where surgical conversion from BPD/DS to RYGB effectively treated this condition. The findings underscore the critical need for preoperative risk assessment for, and careful postoperative management of, hypoparathyroidism in bariatric surgery patients with complex medical histories. This case report outlines a potential treatment pathway for managing refractory hypocalcemia, emphasizing the importance of preserving calcium-absorbing bowel function in patients with BPD/DS anatomy. It provides valuable insights into treating severe hypocalcemia and demonstrates a successful surgical intervention that could inform the management of similar cases.