Background
Many clinicians will prescribe anticoagulation therapy for patients after iliac vein stenting to prevent early or late stent thrombosis. At present, it is unknown whether therapeutic anticoagulation has any effect on stent patency. Thus, we assessed the role of short-term anticoagulation on iliac vein stent patency in patients with nonthrombotic iliac vein lesions (NIVLs).
Methods
We performed a retrospective medical record review of all iliac vein stents placed for NIVLs at the Center for Vascular Medicine from January 2018 to December 2019. We compared the stent patency in the two groups. The anticoagulation (AC) group had received rivaroxaban or apixaban postoperatively for a minimum of 90 days and were compared with a group that had received no postoperative anticoagulation (NAC). Stent patency was assessed using transabdominal ultrasound at 3, 6, 12, 18, 24, and 30 months. At the discretion of the treating physician, the patients who demonstrated thrombus layering on surveillance ultrasound scanning continued rivaroxaban or apixaban until thrombus resolution was observed. The demographics and stent location, diameter, and length were assessed. Stent patency was analyzed using life table analyses. Differences in stent patency were analyzed using GraphPad Prism, version 8, statistical software (GraphPad Software Inc, La Jolla, Calif) and the log-rank (Mantel-Cox) test.
Results
The number of patients and stents in each group were as follows: AC group, 299 patients and 308 stents; and NAC group, 77 patients and 90 stents. The average age was 52.24 ± 13.44 years and 55.63 ± 14.49 years in the AC and NAC groups, respectively (P ≤ .065). Women constituted 76% of the patients in the AC group and 72% in the NAC group. The average stent diameter and length for the AC group was 20 ± 2 mm and 77 ± 13 mm and for the NAC group was 19 ± 2 mm and 82 ± 9 mm, respectively. The stents had been placed in the right common iliac vein, bilaterally, or left common iliac vein territory in 15%, 3%, and 82% in the AC group and 18%, 2%, and 80% in the NAC group, respectively. The cumulative stent patency at 30 months was 98.7% and 94.6% for the NAC and AC groups, respectively (P ≤ .83). All the stents placed were Wallstents (Boston Scientific, Marlborough, Mass). A total of eight insertion site thromboses occurred that did not affect stent patency: five in the AC group (1.6%) and three in the NAC group (4.5%; P = .15). In addition, 19 patients demonstrated evidence of thrombus layering, with 6 receiving extended anticoagulation.
Conclusion
Our data indicate that perioperative stent thrombosis in patients with NIVLs is uncommon. Thus, anticoagulation for perioperative stent thrombosis prophylaxis is not necessary. Anticoagulation should only be used for patients with insertion site thromboses and should be considered if thrombus layering is observed on surveillance scanning.
