title: The carina as a useful radiographic landmark for positioning the intraaortic balloon pump.
abstract: BACKGROUND
  The aortic knob is thought to be the most useful radiographic landmark for the proper positioning of the intraaortic balloon pump (IABP) tip. However, this has not been studied formally. In this study we assessed whether the aortic knob is a reliable landmark for positioning the IABP and compared it with another potential landmark, the carina.
  
  
  METHODS
  We measured the distance from the top of the distal aortic arch (aortic knob) to the left subclavian artery (LSCA) on three-dimensional computed tomography angiography in 100 patients. The distance from the level of the LSCA origin to the level of the carina was also measured using three-dimensional computed tomography in 150 additional patients.
  
  
  RESULTS
  In 16% of the aortic knob study population, the LSCA to aortic knob distance was <0 cm or 0 cm. The median distance from the LSCA to the carina was 42 mm (range: 30-63 mm). In the carina study population, the origin of the LSCA was 35-55 mm above the carina in 95.3% of patients.
  
  
  CONCLUSIONS
  In 16% of patients, the IABP was too close to the LSCA origin when it was placed at the aortic knob, whereas positioning the IABP at 2 cm above the carina provided an adequate position for the IABP tip (1.5-3.5 cm distal to the origin of the LSCA) in 95.3% of patients. The carina may be a more reliable landmark for positioning the IABP than the aortic knob.
authors: Department of Anesthesiology, College of Medicine, Seoul National University, Seoul, Korea.
authors: Jin-Tae
authors: JT
authors: Kim
authors: Jeong-Rim
authors: JR
authors: Lee
authors: Jae-Kwang
authors: JK
authors: Kim
authors: Seung Zhoo
authors: SZ
authors: Yoon
authors: Yunseok
authors: Y
authors: Jeon
authors: Jae-Hyon
authors: JH
authors: Bahk
authors: Ki-Bong
authors: KB
authors: Kim
authors: Chong-Sung
authors: CS
authors: Kim
authors: Young-Jin
authors: YJ
authors: Lim
authors: Hee-Soo
authors: HS
authors: Kim
authors: Seong-Deok
authors: SD
authors: Kim
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001027:Aortography / Q000379:methods; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007423:Intra-Aortic Balloon Pumping / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013348:Subclavian Artery / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014132:Trachea / Q000000981:diagnostic imaging*