Zhang, et al. Management of complicated aortic aneurysms using multiple overlapping uncovered stents: mid-term outcome from a cohort study
Supplement 4: Aneurysm sac pressure measurement
Methods: A 5Fr selective catheter (Cook, Bloomington, Indiana) in connection with a pressure transducer was placed in the aneurysm sac to monitor the local sac systolic pressure (SSP), which was then normalized by the synchronous radial artery pressure (RAP) to get an adjusted value (adjusted sac systolic pressure, ASSP):
, and
in which and stand for the pre- and post-stenting sac systolic pressure, respectively; and stand for the synchronous radial artery pressure before and after stening, respectively. The pressure-taking catheter was withdrawn after all stents were deployed (Figure).
Results:Aneurysm sac pressure was monitored in 19 patients (14 saccular aneurysms and 5 fusiform aneurysms). ASSP decreased form 141.2±20.6 mmHg before stenting to 138.2±17.4 mmHg after stenting, but the change was of no statistical significance (p=.22). Subgroup analysis documented no significant change in ASSP in both saccular (141.5±20.4 mmHg pre-stenting vs. 137.5±16.7 mmHg post-stenting, p=.13) and fusiform aneurysms (140.2±23.8 mmHg vs. 140.2±21.1 mmHg, p＞.99).
Figure: A: the pressure-taking catheter was placed into the aneurysm sac prior to stents deployment to measure the pre-stenting sac systolic pressure (SSPpre); meanwhile the synchronous radial artery pressure (RAPpre) was also documented to adjust SSP (adjusted sac systolic pressure, ASSPpre). B and C: after stents deployment, SSP and RAP was measured again to demonstrate the sac pressure change (SSPpost and RAPpost). Then the pressure-taking catheter was withdrawn from the aneurysm sac.D-G: pressure measurement in a clinical case. D: Pre-operative angiogram confirmed the location of the aneurysm (asterisk) and the segmental arteries adjacent to the lesion segment (black arrow head). E: the pressure-taking catheter (white arrow) was placed into the aneurysm sac before stenting to measure the SSPpre. White arrow head: the stent in position. F: deployment of the stent, leaving the catheter inside the sac to measure the SSPpost(white arrow). White arrow head: the stent deployed. G: completion angiogram showed the patency of segmental arteries within the stenting zone (black arrow heads).