Perioperative Complete Blood Count Changes After Endovascular Aneurysm Repair (EVAR) and Fenestrated EVAR (FEVAR): A Retrospective Cohort Study

Background Endovascular aneurysm repair (EVAR) and fenestrated EVAR (FEVAR) expose the abdominal and pelvic regions to localized radiation, but their hematologic effects remain unclear. Purpose To characterize perioperative changes in complete blood count (CBC) after EVAR/FEVAR and to explore potential associations with radiation exposure in a hypothesis-generating manner. Methods We retrospectively analyzed 75 procedures (64 EVAR, 11 FEVAR) performed in 2022. Hemoglobin (Hb), white blood cells (WBC), neutrophils (Neu), lymphocytes (Lym), and platelets (Plt) were measured at baseline and on postoperative day 1, and at one week, one month, and six months after intervention. Associations with radiation dose (reference-point air kerma), blood loss, and patient characteristics were evaluated. Results CBC parameters showed characteristic early postoperative fluctuations on postoperative day 1: Hb and Plt decreased, Lym declined markedly, and WBC and Neu increased (all P < 0.01). Most values approached baseline by six months. No clear dose-response relationship was observed in the overall cohort; however, exploratory subgroup analyses suggested more sustained reductions in Hb and Lym among males, patients with BMI <23 kg/m², and those receiving ≥1 Gy. Conclusion EVAR/FEVAR were associated with transient perioperative CBC shifts that largely resolved within six months. While radiation dose was not a clear determinant of hematologic changes in the overall cohort, exploratory subgroup findings suggested possible differences in patients with higher exposure or lower BMI; these observations should be interpreted as hypothesis-generating. Further investigations incorporating organ-specific dosimetry are needed to better understand potential hematopoietic effects of complex endovascular procedures.