In-stent restenosis and stent compression in iliofemoral venous stents

I read with great interest the manuscript by Yang et al. (1) that was published recently and wished to congratulate the authors for their excellent management and diagnosis of in-stent restenosis and stent compression in iliofemoral venous stents.

Some points that may be of interest to our esteemed readers are listed as follows:

• The Wallstent™ (Boston Scientific, Marlborough, MA, USA) is one of the most commonly used iliofemoral venous stents. The rate of in-stent restenosis (ISR) and stent compression (SC) with Wallstent™ has been found to be high in several clinical series (2). With the recent advent of the newer nitinol stents in the deep venous space, their long-term rates of ISR and SC are currently unknown. The authors (1) have presented their experience with ISR and SC with the laser-cut nitinol stent (Smart Control, Cordis, USA) which is a valuable addition to the current literature on the topic.
• When available, the use of intravascular ultrasound (IVUS) in the detection of stent malfunction is recommended in view of a recent systematic review on the subject (3) as multiplanar venography can underdiagnose lesions. For iliac vein compression, computed tomography venography (CTV) appears to have an excellent correlation with IVUS metrics (4). However, the use of CTV to determine ISR and SC has not yet been formally validated after performance of iliac venous stenting and this may be one of the drawbacks of the study (1). Did the authors note a correlation between duplex ultrasound and CTV findings in this particular study with regards to SC and ISR?
• Post-stenting, the use of anticoagulation in select patients with post-thrombotic syndrome, poor stent inflow or outflow and thrombophilia conditions is generally advocated (5). However, the role of anticoagulation in patients with iliac vein compression syndrome alone is not well established. The authors stated that patients with thrombophilia conditions were excluded from the study (1). However, it is requested that authors elaborate on the rationale for the use of rivaroxaban in patients who were included in this study. Also, did the authors analyze if anticoagulation had any impact on the rates of ISR or SC? Was an antiplatelet agent added to the regimen for any of the patients? There is at least one study that has reported improved stent patency with anticoagulation and antiplatelet therapy rather than anticoagulation alone (6).
• SC and ISR can occur together or as independent separate pathologies. It has been noted that ISR can occur in stents that are extended below the inguinal ligament (7). Did the authors analyze the relationship of stent extension below the inguinal ligament and ISR/SC?
• The authors (1) noted the rate of stent occlusion was low from ISR/SC (2/50, 4%). This is consistent with prior publications (8). Therefore, ISR and SC do not significantly impact the primary or secondary patency of iliofemoral venous stents. However, due to residual and recurrent symptoms, intervention maybe performed to correct ISR and SC and this will impact the primary-assisted patency of the venous stents.
• It is important to remember that intervention should consider the patient’s symptoms and failure of conservative management rather than being based on a metric that is obtained from an imaging study such as duplex ultrasound or CTV (5).
• For response of authors (1), please see supplemental material (response to “in-stent restenosis and stent compression in iliofemoral venous stents”).

Supplemental material: Response to “in-stent restenosis and stent compression in iliofemoral venous stents”.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article did not undergo external peer review.

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/qims-21-738). The author has no conflicts of interest to declare.

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References

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