title: Non-super-selective venous sampling for persistent hyperparathyroidism using a systemic hypocalcemic challenge.
abstract: OBJECTIVE
  To describe a new protocol employing an acute systemic hypocalcemic challenge (SHC) aimed at augmenting the parathyroid hormone (PTH) gradient to enable non-super-selective venous sampling (VS) in patients with persistent primary hyperparathyroidism (PHPT).
  
  
  METHODS
  In a retrospective study, 37 patients (39 studies-20 SHC, 19 super-selective VS) who underwent VS for persistent or recurrent PHPT were examined. Study patients were pretreated with intravenous hydration, diuretics, and bicarbonate to induce temporary relative hypocalcemia and then underwent non-super-selective VS targeted at large vessels within the neck and chest with rapid PTH testing. The traditional VS protocol involved super-selective VS with arteriography.
  
  
  RESULTS
  SHC decreased ionized calcium by 0.098 mmol/L ± 0.18 (P = .07) and increased peripheral PTH by 10.2 pg/mL (P = .58). Positive VS gradients, defined as a ≥ 1.4-fold difference from baseline to after SHC, were detected in 95% of patients. VS findings guided successful surgery in 77% of SHC cases and 90% of super-selective VS cases; the peak gradient site was concordant with operative findings in 46% of SHC cases and 80% of super-selective VS cases. Avoidance of super-selective sampling decreased mean fluoroscopy time from 91 minutes to 33 minutes and decreased contrast material administered from 204 mL to 63 mL (both P < .0001).
  
  
  CONCLUSIONS
  The SHC protocol to enable non-super-selective VS in patients with persistent PHPT had the same ability as super-selective VS to detect a positive (≥ 1.4-fold) PTH gradient, was associated with decreased accuracy in identifying the site of the adenoma compared with super-selective VS, and significantly decreased contrast material used and fluoroscopy time.
authors: David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
authors: Lilah F
authors: LF
authors: Morris
authors: Christopher
authors: C
authors: Loh
authors: Kevin
authors: K
authors: Ro
authors: James E
authors: JE
authors: Wiseman
authors: Antoinette S
authors: AS
authors: Gomes
authors: Amy
authors: A
authors: Asandra
authors: Samuel
authors: S
authors: Wariri
authors: Michael W
authors: MW
authors: Yeh
mesh_terms: D000236:Adenoma / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001639:Bicarbonates; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood*; D002405:Catheterization, Central Venous; D002406:Catheterization, Peripheral; D004232:Diuretics; D015536:Down-Regulation; D005260:Female; D005440:Fluid Therapy; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D006996:Hypocalcemia / Q000097:blood*; D016015:Logistic Models; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010281:Parathyroid Hormone / Q000097:blood*; D010282:Parathyroid Neoplasms / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D016105:Parathyroidectomy; D011237:Predictive Value of Tests; D015641:Radiography, Interventional; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D001639:Bicarbonates; D015415:Biomarkers; D004232:Diuretics; C470125:PTH protein, human; D010281:Parathyroid Hormone; D002118:Calcium