title: Aneurysmal pressure changes with nondetachable balloon placement and fluid infusion: rationale for liquid embolization.
abstract: OBJECTIVE
  To improve the safety and efficacy of liquid embolization, we evaluated changes in pressures in experimental aneurysms.
  
  
  METHODS
  We created three replicas of a lateral sidewall aneurysm and placed them in a physiologic flow circuit. A 3 x 10-mm nondetachable balloon was positioned in the parent vessel across the aneurysmal neck. Intra-aneurysmal pressures were measured at baseline and after balloon inflation. Fluid was infused into the sac via a 1.45F microcatheter during inflation, and maximal pressures were noted. Measurements were repeated eight times in each aneurysm.
  
  
  RESULTS
  After balloon inflation, average intra-aneurysmal pressures increased: 12 mm Hg (13%, sigma(n - 1) = 0.46) for aneurysm 1 (baseline mean arterial pressure [MAP], 94 mm Hg), 15 mm Hg (58%, sigma(n - 1) = 0.88) for aneurysm 2 (baseline MAP, 26 mm Hg), and 15 mm Hg (58%, sigma(n - 1) = 0.92) for aneurysm 3 (baseline MAP, 26 mm Hg). During inflation and infusion, pressures increased slightly: 1.1 (0.94%, sigma(n - 1) = 0.64), 1.6 (3.9%, sigma(n - 1) = 1.1), and 1.9 (4.6%, sigma(n - 1) = 1.2) mm Hg for aneurysms 1, 2, and 3, respectively. Despite complete balloon occlusion of the distal aneurysmal neck, a channel between the proximal aneurysmal neck and the parent-vessel lumen persisted along the microcatheter. Fluid exited the sac via this channel, preventing a concomitant, significant increase in pressure during infusion.
  
  
  CONCLUSIONS
  Intra-aneurysmal pressure modestly increased with inflation of a parent-vessel balloon across the neck. When liquid was infused into the sac during inflation, further increases were minimal.
authors.affiliation: Department of Radiology, University of California, San Diego Medical Center, Mail Code 8756, San Diego, CA 92103, USA.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Imbesi
authors.forename: Kimberly
authors.initials: K
authors.lastname: Knox
authors.forename: Charles W
authors.initials: CW
authors.lastname: Kerber
mesh_terms: D000800:Angioplasty, Balloon / Q000295:instrumentation; D004621:Embolization, Therapeutic / Q000295:instrumentation / Q000379:methods*; D002532:Intracranial Aneurysm / Q000503:physiopathology* / Q000628:therapy*; D011312:Pressure