Intraoperative sac pressure measurement during endovascular abdominal aortic aneurysm repair

Intraoperative sac pressure was measured during endovascular abdominal aortic aneurysm repair (EVAR) to evaluate the clinical significance of sac pressure measurement.

A microcatheter was placed in an aneurysm sac from the contralateral femoral artery, and sac pressure was measured during EVAR procedures in 47 patients. Aortic blood pressure was measured as a control by a catheter from the left brachial artery.

The systolic sac pressure index (SPI) was 0.87 +/- 0.10 after main-body deployment, 0.63 +/- 0.12 after leg deployment (P < 0.01), and 0.56 +/- 0.12 after completion of the procedure (P < 0.01). Pulse pressure was 55 +/- 21 mmHg, 23 +/- 15 mmHg (P < 0.01), and 16 +/- 12 mmHg (P < 0.01), respectively. SPI showed no significant differences between the Zenith and Excluder stent grafts (0.56 +/- 0.13 vs. 0.54 +/- 0.10, NS). Type I endoleak was found in seven patients (15%), and the SPI decreased from 0.62 +/- 0.10 to 0.55 +/- 0.10 (P = 0.10) after fixing procedures. Type II endoleak was found in 12 patients (26%) by completion angiography. The SPI showed no difference between type II endoleak positive and negative (0.58 +/- 0.12 vs. 0.55 +/- 0.12, NS). There were no significant differences between the final SPI of abdominal aortic aneurysms in which the diameter decreased in the follow-up and that of abdominal aortic aneurysms in which the diameter did not change (0.53 +/- 0.12 vs. 0.57 +/- 0.12, NS).

Sac pressure measurement was useful for instant hemodynamic evaluation of the EVAR procedure, especially in type I endoleaks. However, on the basis of this small study, the SPI cannot be used to reliably predict sac growth or regression.