title: The inferior emissary vein: a reliable landmark for right adrenal vein sampling.
abstract: BACKGROUND
  Right adrenal vein (RAV) catheterization can be a very challenging step in adrenal venous sampling (AVS). Visualization of the inferior emissary vein (IEV) may be an indication of successful RAV catheterization.
  
  
  OBJECTIVE
  To compare the rate of successful RAV sampling in the presence of the IEV.
  
  
  METHODS
  Retrospective review of all consecutive patients with PA who underwent AVS between April 2009 and April 2012 was performed. A total of 30 patients were identified. Procedural images, cortisol, and aldosterone values obtained from sampling of the RAV and inferior vena cava (IVC) were reviewed. Cortisol measurements obtained from RAV samples were divided by measurements from the infra-renal IVC blood samples in order to calculate the selectivity index (SI). An SI >3 was considered indicative of technically successful RAV sampling.
  
  
  RESULTS
  RAV sampling was considered technically successful in 29 out of 30 cases (97%). In cases of successful RAV sampling (29 patients), the IEV was identified in 25 patients (86%). The IEV was visualized in isolation in 16 patients (64%), and in conjunction with visualization of the RAV or right adrenal gland stain in nine patients (36%). The IEV was not visualized in the one case of unsuccessful RAV sampling. Visualizing the IEV had a sensitivity of 86.2% for successful RAV sampling.
  
  
  CONCLUSIONS
  The IEV may serve as a reliable landmark for the RAV during RAV sampling.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA maureen.kohi@ucsf.edu.
authors.forename: Maureen P
authors.initials: MP
authors.lastname: Kohi
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Vishal K
authors.initials: VK
authors.lastname: Agarwal
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Naeger
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Taylor
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: K Pallav
authors.initials: KP
authors.lastname: Kolli
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Fidelman
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: LaBerge
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Kerlan
mesh_terms: D000293:Adolescent; D000311:Adrenal Glands / Q000098:blood supply*; D000328:Adult; D000368:Aged; D001800:Blood Specimen Collection / Q000379:methods*; D002406:Catheterization, Peripheral / Q000379:methods*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014680:Veins / Q000033:anatomy & histology*; D055815:Young Adult
chemical_list: D006854:Hydrocortisone
keywords: Interventional; adrenal; adults; anatomy; endocrine disorders; veins