Stent-Induced Inflammation: A Comparative Cross-Sectional Study of Post-Implantation Syndrome in Venous and Arterial Procedures

<b>Background:</b> Postimplantation syndrome (PIS) is a known inflammatory response following endovascular stent placement, yet comparative data between venous and arterial stenting remains limited. This study seeks to evaluate the incidence, characteristics, and clinical implications of PIS across these two distinct vascular territories. <b>Methods:</b> We retrospectively analyzed 191 patients who underwent either venous (n = 36) or arterial (n = 155) stent placement. Data collection encompassed demographic profiles, perioperative laboratory findings, and clinical outcomes. The primary endpoint was the incidence of PIS, defined as the presence of fever (≥38 °C), leukocytosis, and elevated C-reactive protein (CRP) within 30 days postprocedure. Secondary outcomes included length of hospital and ICU stay, incidence of endoleaks, reintervention rates, and 30-day mortality. Comparative statistical analyses were conducted to assess differences between the venous and arterial stent groups. <b>Results:</b> PIS was observed more frequently in arterial stent patients, as evidenced by significantly elevated postoperative white blood cell counts at 24 and 48 h (<i>p</i> = 0.046 and <i>p</i> = 0.014, respectively), along with borderline CRP increases (<i>p</i> = 0.052). Fever occurrence peaked at 72 and 96 h postprocedure, predominantly in the arterial cohort. Furthermore, patients with arterial stents had significantly longer hospital stays (5.59 ± 0.46 days vs. 3.42 ± 0.36 days; <i>p</i> = 0.0018) and a higher rate of 30-day endoleaks (7.1% vs. 0%; <i>p</i> = 0.005). Despite similar mortality and major adverse cardiac event (MACE) rates between groups, arterial stent patients exhibited a greater need for reintervention. While PIS was less common among venous stent recipients, its potential impact on postoperative recovery warrants careful monitoring. <b>Conclusions:</b> Arterial stenting is associated with a higher incidence of PIS and a more pronounced systemic inflammatory response, contributing to longer hospitalization and increased postoperative complications. Although venous stent patients experience PIS less frequently, its occurrence should not be overlooked, as it may influence overall recovery and clinical outcomes. Recognition and management of PIS in both venous and arterial stent patients are critical to improving patient care and optimizing procedural success.