Comparative study on the Inflammatory Response after Endovascular Aortic aneurysm Repair and Endovascular Aneurysm Sealing

Endovascular sealing of abdominal aortic aneurysms (EVAS) is a new technique to
treat infrarenal abdominal aortic aneurysms (AAA), which can be performed more
expeditiously than endovascular aneurysm repair (EVAR). The difference with
EVAR is that fixation and seal are provided from polymer filled endobags that
are placed in the aneurysmal sac. The post-implantation syndrome (PIS) is the
clinical and biochemical expression of an inflammatory response following
endovascular repair of an aortic aneurysm. More specifically, the presence of
fever (body temperature >38 C for *1 day) and leukocytosis (WBC >12.000/mL)
with negative blood cultures and is occurring in over 30% cases after EVAR. It
is related to prolonged hospital stay and elevated CRP levels, that in turn
increase the risk on major adverse cardiac events. The presence of PIS is an
independent predictor of an adverse event during the first 30 days. Sartipy et
all (2015) showed that the magnitude of the post-operative inflammatory
response depends on the type of endoprosthesis used for EVAR. Anecdotal reports
suggest that EVAS causes a dampened inflammatory response compared to EVAR.
Berg et all (2017) recently showed that EVAS is related to a lower
postoperative CRP level, lower white blood counts and a lower temperature,
compared to standard EVAR. In addition, less cardiac complications were seen.
This difference may be due to many factors, including the avoidance of fresh
luminal thrombosis after EVAS (as the endobags completely fill the aneurysm
flow lumen) and/or the different physical properties of the endograft. If
confirmed, this may result in improved clinical outcome, as the magnitude of
the post-operative inflammatory response has been correlated with the
occurrence of complications. The one-year data of the EVAS-FORWARD Global
showed a higher than expected freedom from all-cause mortality rate (95%),
mainly driven by a 98% freedom from cardiovascular death. The current study was
designed to compare the occurrence of the post-implantation syndrome after EVAR
and EVAS of people aged 50 years and older since aneurysms that occur at young
age are mostly inflammatory. This study was also designed to unravel the
cytokines which are involved in the post-implantation syndrome after EVAR and
EVAS.

Primary objective
To establish whether EVAS results in a reduced post-operative inflammatory
response , reflected by a lower incidence of the post-implant syndrome, during
the first year after surgery, compared to EVAR as assessed by trends in
circulating inflammatory cytokine concentration.

Secondary objectives
1. To establish if there is a difference in the incidence of the Post Implant
Syndrome between EVAR and EVAS.
2. To establish whether the post-operative inflammatory response after
EVAR/EVAS is proportional to changes in aortic intra-luminal thrombus.
3. To investigate the relationship between the measured post-implant
inflammatory response and cardiac damage as measured by troponin and Pro-BNP
and cardiac adverse events.

A prospective observational comparative study.

Abdominal Aortic Aneurysm is a life threatening condition. Although treatment
of these aneurysms with endovascular devices is generally safe, intra-operative
and post-operative complications can and do occur. In this observational study
all surgical or medical procedures will performed per standard of care at each
participating Institute. The study protocol itself does not therefore introduce
any additional risk for the patient.
Patients treated with endovascular devices are generally monitored on an annual
basis to detect device related complications or disease expansion, with a more
intense surveillance during the first year. This study protocol will collect
routine clinical data at specified time points and will not require additional
patient visits or investigations, except for the blood sampling which is
mandatory.
There are no direct harms or benefits to an individual patient associated with
participation in this study. However, collectively the data generated by this
study will benefit the medical and surgical communities* understanding of the
performance of the studied devices.