title: Intra-aneurysm sac pressure measurements after endovascular aneurysm repair: differences between shrinking, unchanged, and expanding aneurysms with and without endoleaks.
abstract: OBJECTIVE
  Our objective was to study intra-aneurysm pressure after endovascular aneurysm repair (EVAR) in shrinking, unchanged, and expanding abdominal aortic aneurysms (AAAs) with and without endoleaks.
  
  
  METHODS
  Direct intra-aneurysm sac pressure measurement (DISP) by percutaneous translumbar puncture of the AAA under fluoroscopic guidance was performed 46 times during the follow-up of 37 patients (30 men; median age, 73 years [range, 58-82 years]; AAA diameter: median, 60 mm [range, 48-84 mm]). Three patients were included in two different groups because DISP was performed more than once with different indications. Tip-pressure sensors mounted on 0.014-inch guidewires were used for simultaneous measurement of systemic and AAA sac pressures. Mean pressure index (MPI) was calculated as the percentage of mean intra-aneurysm pressure relative to the simultaneous mean intra-aortic pressure.
  
  
  RESULTS
  Median MPI was 19% in shrinking (11 patients), 30% in unchanged (10 patients), and 59% in expanding (9 patients) aneurysms without endoleaks. Pulse pressure was also higher in expanding (10 mm Hg) compared with shrinking (2 mm Hg; P <.0001) AAAs. Four of the nine patients with expanding AAAs underwent five repeated DISPs later in the follow-up, and MPIs were consistently elevated. Seven of the 10 patients with unchanged AAAs without endoleaks underwent further computed tomography follow-up after DISP; 2 expanded (MPI, 47%-63%), 4 shrank (MPI, 21%-30%), and 1 remained unchanged (MPI, 14%). Type II endoleaks (6 patients, 7 DISPs) were associated with wide range of MPI (22%-92%). Successful endoleak embolization (n = 4) resulted in pressure reduction.
  
  
  CONCLUSIONS
  Intra-aneurysm sac pressure measurement is an important adjunctive for EVAR evaluation, possibly allowing early detection of failures. High pressure is associated with AAA expansion and low pressure with shrinkage. Type II endoleaks can be responsible for AAA pressurization, and successful embolization appears to result in pressure reduction.
authors.affiliation: Endovascular Center, Department of Radiology, UMAS, Malmö University Hospital, S-205 02 Malmö, Sweden. nunovdias@hotmail.com
authors.forename: Nuno V
authors.initials: NV
authors.lastname: Dias
authors.forename: Krassi
authors.initials: K
authors.lastname: Ivancev
authors.forename: Martin
authors.initials: M
authors.lastname: Malina
authors.forename: Timothy
authors.initials: T
authors.lastname: Resch
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindblad
authors.forename: Björn
authors.initials: B
authors.lastname: Sonesson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D003971:Diastole / Q000502:physiology; D004621:Embolization, Therapeutic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D012086:Reoperation; D013548:Sweden; D013599:Systole / Q000502:physiology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures