Endovascular repair of thoracic and abdominal aortic aneurysms (EVAR/TEVAR) has become a
preferred alternative to open surgical repair due to its association with reduced
perioperative morbidity and mortality. However, a notable proportion of patients
undergoing these procedures may develop postimplantation syndrome (PIS), a systemic
inflammatory response first described in 1999. Despite its clinical relevance, PIS
remains poorly defined, with varying diagnostic criteria across the literature.
PIS is typically characterized by postoperative fever, fatigue, and an increase in
inflammatory markers such as white blood cell (WBC) count, C-reactive protein (CRP), and
interleukin-6 (IL-6). The neutrophil-to-lymphocyte ratio (NLR), a readily obtainable
marker from complete blood count tests, has also gained attention as a reliable indicator
of systemic inflammation. In contrast, procalcitonin levels in PIS patients often remain
within normal limits, helping differentiate PIS from bacterial infections.
In this prospective observational study, 200 patients undergoing elective EVAR or TEVAR
procedures under general anesthesia were included. All procedures were performed via
bilateral femoral artery access using open femoral incisions. Patients were followed
postoperatively and assessed for the development of PIS based on clinical and laboratory
parameters.
Body temperature was measured at regular intervals, and inflammatory markers-including
CRP, WBC count, IL-6, NLR, and procalcitonin-were recorded preoperatively and at 24, 48,
and 72 hours postoperatively. PIS was defined as the presence of fever (>38°C) in
association with elevated CRP and/or leukocytosis, in the absence of any clinical or
microbiological evidence of infection.
Preliminary results showed that patients who developed PIS had significantly higher
postoperative levels of WBC, CRP, IL-6, and NLR, while procalcitonin levels remained
normal, supporting a non-infectious inflammatory etiology. Imaging and laboratory
evaluations ruled out alternative sources of infection. No significant differences were
observed in operative time or graft type between patients with and without PIS.
All data were collected prospectively and analyzed using the SPSS statistical software.
The study aims to clarify the diagnostic criteria of PIS by identifying specific
laboratory biomarkers that can reliably differentiate PIS from other postoperative
complications, particularly infection. Furthermore, by better understanding the
inflammatory response following EVAR/TEVAR, the study may contribute to improved
postoperative management strategies.
