title: Selective inferior petrosal sinus sampling without venous outflow diversion in the detection of a pituitary adenoma in Cushing's syndrome.
abstract: BACKGROUND
  Conventional MRI may still be an inaccurate method for the non-invasive detection of a microadenoma in adrenocorticotropin (ACTH)-dependent Cushing's syndrome (CS). Bilateral inferior petrosal sinus sampling (BIPSS) with ovine corticotropin-releasing hormone (oCRH) stimulation is an invasive, but accurate, intervention in the diagnostic armamentarium surrounding CS. Until now, there is a continuous controversial debate regarding lateralization data in detecting a microadenoma. Using BIPSS, we evaluated whether a highly selective placement of microcatheters without diversion of venous outflow might improve detection of pituitary microadenoma.
  
  
  METHODS
  We performed BIPSS in 23 patients that met clinical and biochemical criteria of CS and with equivocal MRI findings. For BIPSS, the femoral veins were catheterized bilaterally with a 6-F catheter and the inferior petrosal sinus bilaterally with a 2.7-F microcatheter. A third catheter was placed in the right femoral vein. Blood samples were collected from each catheter to determine ACTH blood concentration before and after oCRH stimulation.
  
  
  RESULTS
  In 21 patients, a central-to-peripheral ACTH gradient was found and the affected side determined. In 18 of 20 patients where transsphenoidal partial hypophysectomy was performed based on BIPSS findings, microadenoma was histologically confirmed. BIPSS had a sensitivity of 94% and a specificity of 67% after oCRH stimulation in detecting a microadenoma. Correct localization of the adenoma was achieved in all Cushing's disease patients.
  
  
  CONCLUSIONS
  BIPSS remains the gold standard in the detection of a microadenoma in CS. Our findings show that the selective placement of microcatheters without venous outflow diversion might further enhance better recognition to localize the pituitary tumor.
authors.affiliation: University Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Freiburgstrasse 4, Bern, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Andereggen
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schroth
authors.forename: Jan
authors.initials: J
authors.lastname: Gralla
authors.forename: Rolf
authors.initials: R
authors.lastname: Seiler
authors.forename: Luigi
authors.initials: L
authors.lastname: Mariani
authors.forename: Jürgen
authors.initials: J
authors.lastname: Beck
authors.forename: Hans-Rudolf
authors.initials: HR
authors.lastname: Widmer
authors.forename: Robert H
authors.initials: RH
authors.lastname: Andres
authors.forename: Emanuel
authors.initials: E
authors.lastname: Christ
authors.forename: Christoph
authors.initials: C
authors.lastname: Ozdoba
mesh_terms: D000236:Adenoma / Q000097:blood* / Q000175:diagnosis; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000368:Aged; D000792:Angiography; D002404:Catheterization; D002648:Child; D003480:Cushing Syndrome / Q000097:blood*; D005260:Female; D005268:Femoral Vein; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017591:Petrosal Sinus Sampling / Q000379:methods*; D010911:Pituitary Neoplasms / Q000097:blood* / Q000175:diagnosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000324:Adrenocorticotropic Hormone