Are Intra-sac Pressure Measurements Useful Following Endovascular Repair of Abdominal Aortic Aneurysms?

Abstract

Although the need for long term postoperative surveillance following endovascular abdominal aortic aneurysm repair is universally agreed upon, the specific surveillance regimen remains controversial. Over the last number of years we have seen the progression of this surveillance from regular CT scans to ultrasounds and plain films. Physiologic or hemodynamic surveillance has been explored via direct intrasac pressure measurements or noninvasive sac pressure monitoring which is the subject of the current debate between Dr. Milner and Professor Cao. Prior to the development of this technology, aneurysm sac behavior, as determined by CT scans or ultrasounds, was used as a surrogate marker for sac pressurization. It is assumed that a shrinking aneurysm is a sign of a successfully excluded aneurysm, while an enlarging aneurysm is indicative of systemic pressurization, irrespective of the presence or type of endoleak. Early proponents of intrasac pressure monitoring envisioned a role for this technology in determining which type II endoleaks in stable aneurysm sacs required further intervention. As type II endoleak development and behavior is unpredictable, sensors would have to be implanted in all patients if they are to benefit this group. So the question remains whether the additional cost of such implants is warranted given the current information available? Dr. Milner and Professor Cao outline the information obtained to date, and seem to arrive at similar conclusions. Although there is evidence to support the usefulness of implantable sensors in selected individual patients, this is often after the fact and there is insufficient evidence to support their implantation in all patients undergoing endovascular aneurysm repair. They have, however, allowed us to learn more about sac pressure patterns and behavior post repair, and have moved us closer to a truly noninvasive, physiologic based surveillance tool. Part One: For the Motion. Serial Sac Pressure Measurements can Determine Which Type II Endoleaks can be TreatedEuropean Journal of Vascular and Endovascular SurgeryVol. 41Issue 2PreviewRepair of abdominal aortic aneurysms (AAA) was revolutionized by the introduction of endovascular aneurysm repair (EVAR) by Dr. Juan Parodi.1 The devices utilized to treat aortic aneurysms have improved significantly since his initial report in 1991. Therefore, the incidence of device-related endoleaks (type I and III) occurs less frequently in this 3rd decade of EVAR as compared to when devices first received FDA approval. On the other hand, type II endoleaks remain controversial. The branch vessel filling of the sac (e.g. Full-Text PDF Open ArchivePart Two: Against the Motion. Measuring Intra-sac Pressure Measurements is of No Benefit to the PatientEuropean Journal of Vascular and Endovascular SurgeryVol. 41Issue 2PreviewThe goal of any treatment of aortic aneurysm is to prevent rupture. From an endovascular standpoint this purpose is achieved by eliminating flow in the aneurysm sac. Failure to completely exclude the aneurysm from systemic circulation (e.g. endoleak, endotension) results in continued pressurisation and persisting risk of expansion/rupture. Measurement of sac pressure provides a physiological assessment of success. After the first experiences showing feasibility and reliability of direct percutaneous translumbar intra-sac pressure measurement with catheters1,2 the development of minimally invasive implantable telemetric pressure sensors was increasingly advocated in the last decade as an easy and convenient method for surveillance after endovascular aneurysm repair. Full-Text PDF Open Archive