title: EUS-guided portal vein carbon dioxide angiography: a pilot study in a porcine model.
abstract: BACKGROUND
  Direct portal vein (PV) angiography can provide valuable clinical information but is not performed due to the high risk of complications.
  
  
  OBJECTIVE
  To assess the feasibility of EUS-guided PV angiography with a small-caliber FNA needle by using carbon dioxide (CO(2)) as a contrast agent in a porcine model.
  
  
  METHODS
  Acute experiments with 50-kg pigs under general anesthesia.
  
  
  METHODS
  Under linear array EUS guidance, the intrahepatic PV branch was punctured with a 25-gauge FNA needle. Portal venography was performed with iodinated contrast (Hypaque) and then with medical grade CO(2). After portography, the needle was removed from the PV and the animals were observed for 30 minutes, then euthanized for necropsy.
  
  
  METHODS
  Ability to visualize portal anatomy.
  
  
  RESULTS
  Six animal experiments were performed without complications. EUS-guided PV puncture with 25-gauge FNA needle was technically straightforward. Injection of ionic iodinated contrast through the 25-gauge FNA needle was arduous (mean [+/-SD] pressure 76.7 +/- 5.2 pounds per square inch [psi]), resulting in short (6.02 +/- 1.15 seconds) and poor opacification of the PV (visualization score 1.33 +/- 0.52). CO(2) injection through a 25-gauge needle was simple and easy (pressure 20.8 +/- 2.0 psi), producing prolonged (19.83 +/- 1.68 seconds) opacification of the entire portal system (visualization score 4.33 +/- 0.52). There was a statistically significant difference in all compared parameters (P < .0001) favoring injection of CO(2) over viscous iodinated contrast during portal angiography through a 25-gauge FNA needle. Postmortem examination revealed no active bleeding and no damage to the liver, other intra-abdominal organs, or blood vessels.
  
  
  CONCLUSIONS
  Acute animal experiments.
  
  
  CONCLUSIONS
  EUS-guided portal venography with CO(2) using a small (25 gauge) FNA needle appears feasible, technically simple, and safe.
authors: Department of Medicine, Division of Gastroenterology, Johns Hopkins Hospital, Baltimore, Maryland 21205, USA.
authors: Samuel A
authors: SA
authors: Giday
authors: Chung-Wang
authors: CW
authors: Ko
authors: John O
authors: JO
authors: Clarke
authors: Eun Ji
authors: EJ
authors: Shin
authors: Priscilla
authors: P
authors: Magno
authors: Sanjay B
authors: SB
authors: Jagannath
authors: Jonathan M
authors: JM
authors: Buscaglia
authors: Sergey V
authors: SV
authors: Kantsevoy
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage; D003287:Contrast Media / Q000008:administration & dosage*; D004195:Disease Models, Animal; D019160:Endosonography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006975:Hypertension, Portal / Q000000981:diagnostic imaging; D007275:Injections, Intravenous; D010690:Phlebography / Q000379:methods*; D010865:Pilot Projects; D011169:Portal Vein / Q000000981:diagnostic imaging*; D013552:Swine
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide