In Stent Re-stenosis Biopsy Findings and Stent Failure Risk Factors in Iliofemoral Venous Stenting: Analysis of 151 Biopsy Samples in 84 Patients and Long Term Outcomes.

Abstract

Endovascular iliofemoral venous stenting has low morbidity; however, in stent re-stenosis (ISR) remains a significant complication that may require re-intervention. This single centre, retrospective study aimed to evaluate ISR biopsy findings and risk factors for stent failure in patients with iliofemoral venous stents. Eighty-four patients (mean age 45.3 ± 16.0 years) who underwent iliac vein stenting and endovascular biopsies between January 2008 and January 2021 were included. Catheter based venography and endovascular biopsies were performed at 3 - 12 and 12 - 24 months after stenting. Logistic regression and Cox regression analyses were conducted to assess the factors associated with severe ISR (ISR degree ≥ 50%) and stent failure. Stent patency time was estimated using Kaplan-Meier curves. Over a mean follow up of 67.4 ± 43.4 months, stent failure occurred in 27 patients (32.1%), including 10 (11.9%) before the second venographic evaluation. At the first biopsy, 38.1% exhibited fresh or organising thrombus, while 61.9% exhibited old thrombus or diffuse intimal thickening (DIT). At the second biopsy, 28.1% had fresh or organising thrombus and 71.9% had old thrombus or DIT. A prothrombotic state (odds ratio 17.862; p = .003) was the significant risk factor for severe ISR within 12 months after stenting, whereas age > 45 years was protective (odds ratio 0.102; p = .009). Patients with fresh or organising thrombus had a statistically significantly higher incidence of stent failure compared with those with old thrombus or DIT (first: 50.0 vs. 21.2%, p = .008; second: 56.3 vs. 19.5%, p = .010). Jalaie type 3 lesions exhibited statistically significantly greater ISR than Jalaie type 2 at both time points (p = .008 and p = .001). Severe ISR between 12 - 24 months after stenting was the predictor for stent failure (hazard ratio 21.573; p = .001). ISR biopsy demonstrating fresh or organising thrombus was associated with a significantly higher risk of stent failure. Early identification of high risk patients can inform risk stratification and post-stenting management strategies.