title: Recalcitrant hypocalcaemia in a patient with post-thyroidectomy hypoparathyroidism and Roux-en-Y gastric bypass.
abstract: Roux-en-Y gastric bypass (RYGB) places patients at an increased risk of hypocalcaemia due to the reduction in calcium absorption (because the procedure bypasses the duodenum and jejunum) and vitamin D deficiency. Subsequent thyroid surgery increases the risk of severe hypocalcaemia due to potential post-operative hypoparathyroidism. Only a few cases have been published before of this type of treatment-challenging hypocalcaemia.
  
  
  
  We report the case of a 31-year-old woman with a previous RYGB, who suffered severe and symptomatic chronic hypocalcaemia after total thyroidectomy. She required aggressive therapy with oral calcium and calcitriol and frequent calcium infusions, but there was no improvement in serum calcium level. Due to the lack of response to standard therapy, teriparatide treatment was started (first with subcutaneous injections and thereafter with a multipulse subcutaneous infusor) but the results were disappointing. As there was no response to different medical treatments, reversal of RYGB was performed with no complications and a subsequent sustained increase in serum calcium level.
  
  
  
  This case shows that patients with postoperative hypoparathyroidism and RYGB have increased risk of severe recalcitrant symptomatic hypocalcaemia. In our case teriparatide was ineffective but, as this is the first patient reported, more results are needed to evaluate properly the effect of teriparatide in this multifactorial hypocalcaemia. Reversal of RYGB should be considered when medical therapy has failed, because surgery restores an adequate absorption of calcium and vitamin D from previously bypassed duodenum and proximal jejunum.
authors.affiliation: Endocrinology Service, 12 de Octubre University Hospital, UCM, Spain. Electronic address: gonzaloallo.endo@gmail.com.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Allo Miguel
authors.affiliation: Endocrinology Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: García Fernández
authors.affiliation: Endocrinology Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Martínez Díaz-Guerra
authors.affiliation: Endocrinology Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Valero Zanuy
authors.affiliation: General Surgery Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Pérez Zapata
authors.affiliation: General Surgery Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: de la Cruz Vigo
authors.affiliation: Endocrinology Service, 12 de Octubre University Hospital, UCM, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: Hawkins Carranza
mesh_terms: D000328:Adult; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D004386:Duodenum / Q000378:metabolism / Q000601:surgery; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000188:drug therapy / Q000209:etiology* / Q000601:surgery; D007011:Hypoparathyroidism / Q000209:etiology*; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism / Q000601:surgery; D009765:Obesity / Q000601:surgery; D011183:Postoperative Complications; D019379:Teriparatide / Q000627:therapeutic use; D013965:Thyroidectomy / Q000009:adverse effects*; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D050071:Bone Density Conservation Agents; D019379:Teriparatide; D014807:Vitamin D; D002118:Calcium
keywords: Hypocalcaemia; Hypoparathyroidism; Obesity; Roux-en-Y gastric bypass; Total thyroidectomy