Back to 2016 Annual Symposium Abstacts

Objective: The optimal catheter directed therapy for femoropopliteal in-stent restenosis (ISR) remains controversial with limited durability. The natural history of untreated ISR is not well characterized. We evaluated the mid-term outcomes of patients with asymptomatic isolated femoropopliteal ISR who were observed under a surveillance program.
Methods: Femoropopliteal stents placed in patients from January 2009-December 2013 were retrospectively investigated for the development of ISR. ISR was classified using duplex criteria with >50% defined as peak systolic velocity (PSV) twice that of normal vessel, and >75% as PSV >400cm/s or four times normal PSV. Asymptomatic patients with ISR of >50% were tracked for progression to high-grade (>75%) stenosis, occlusion, need for re-intervention, and amputation.
Results: Asymptomatic ISR of >50% was identified in 62 (15.3%) of 402 patients with isolated femoropopliteal stents. Mean time to develop ISR was 22.1 (+/- 20.1) months. Mean age was 72 (+/- 9.7) years old, and 34 (55.7%) patients were female. Thirty one (50%) patients were diabetic, 18 (29.1%) were smokers, and 8 (12.9%) had chronic kidney disease. Indications for treatment were claudication in 49 (79.0%), tissue loss in 9 (14.5%) and rest pain in 4 (6.4%) patients. TASC A, B, and C lesions were treated in 13 (21%), 24 (38.7%) and 25 (40.3%) patients respectively. Three, two and one vessel runoff was identified in 25 (40.3%), 18 (29.0%), and 19 (30.6%) patients, respectively.
While under surveillance, ISR of >50% progressed to >75% or occlusion in 20 (32.3%) patients. Mean time to progression was 17.4 months, and mean overall follow-up was 33.1 months. Re-intervention was required in 22 (35.0%) patients with an average of 1.95 (range 1-4) interventions per patient. Nineteen (86%) patients were re-intervened on for claudication and 3 (18%) for critical limb ischemia. One patient required an amputation despite prior re-intervention for progression. Progression to >75% stenosis was predictive of need for re-intervention (P=0.004).
Conclusion: Under a surveillance program, asymptomatic patients with femoropopliteal ISR greater than 50% may be followed with a low risk of limb loss. Given the slow rate of progression, and the poor durability of re-intervention, surveillance with delayed intervention may be warranted.

Patients with >50% ISR (n=62)

	Time to progression (months)	Mean Follow-up (months)	Patients requiring Intervention (%)	No. of Interventions (per pt)
Unchanged >50% (n=42)		33.9 (range: 6.3-104.3)	10 (23.8%)	18 (1.8)
>75% (n=17)	20.5(range: 6.9-68.3)	37.8 (range: 6.9-68.3)	10 (58.8%)	24 (2.2)
Occluded (n=3)	14.3(range: 5.4-16.8)	30.3 (range: 11.4-63.2)	2 (66.7%)	3 (1.5)