Intra-aneurysm Sac Pressure Measurement Using a Thin Pressure Wire During Endovascular Aneurysm Repair

Background: An endoleak is a typical complication of endovascular aneurysm repair (EVAR). It is characterized by persistent blood flow between a stent graft and the aneurysm sac. Usually, it can be visualized during primary EVAR, but in many cases, this remains impossible. Therefore, other methods of endoleak assessment are urgently needed. The measurement of aneurysm sac pressure (ASP) seems to be a promising direction of research in this area.

Objectives: We aimed to evaluate the safety and efficacy of a new method for invasive pressure measurement inside the abdominal aortic aneurysm (AAA) during EVAR. We also assessed a correlation between pressure values and early angiographic occurrence of an endoleak after the procedure.

Material And Methods: A total of 20 patients with AAA were included in this experimental prospective study. During EVAR, systolic, diastolic and mean pressure values were recorded both for ASP and aortic pressure (AP) before procedure, after stent graft opening and after final stent graft ballooning.

Results: The measurements were successfully obtained in all participants without any complications. There were no significant differences between all ASP and AP before procedure. After the procedure, blood pressure significantly decreased in the aneurysm sac but not in the aorta. Systolic ASP was significantly lower than systolic AP both after stent graft opening (80.4 ±20.9 mm Hg compared to 110.7 ±21.6 mm Hg, p < 0.01) and after its balloon post-dilatation (65.6 ±26.1 mm Hg compared to 107.4 ±22.1 mm Hg, p < 0.001). Diastolic ASP decreased significantly in comparison to diastolic AP only after stent graft ballooning (48.0 ±14.6 mm Hg compared to 56.4 ±13.6 mm Hg, p < 0.05).

Conclusions: Our study confirmed that the novel method for the measurement of ASP during EVAR, using a thin pressure wire, is feasible and safe.