Calcified in-stent restenosis in a venous stent

TNFα activation and TGFβ blockage act synergistically for smooth muscle cell calcification in patients with venous thrombosis via TGFβ/ERK pathway

Venous calcification has been observed in post‐thrombotic syndrome (PTS) patients; yet, the cell types and possible mechanisms regulating this process are still unclear. We evaluated the calcium deposition within the venous wall, the cell type involved in the calcified remodelling of the venous wall after thrombosis and explored possible mechanisms in vitro. Calcium deposition was found in human specimens of superficial thrombotic veins and was co‐localized with VSMCs markers αSMA and TAGLN (also known as SM22α). Besides, the expression of osteogenesis‐related genes was dramatically changed in superficial thrombotic veins. Moreover, the inhibition of the TGFβ signalling pathway after TNFα treatment effectively induced the expression of osteogenic phenotype markers, the calcium salt deposits and the obvious phosphorylation of ERK1/2 and JNK2 in the VSMCs calcification model. Supplementing TGFβ2 or blocking the activation of the ERK/MAPK signalling pathway prevented the transformation of VSMCs into osteoblast‐like cells in vitro. Taken together, VSMCs have an important role in venous calcification after thrombosis. Supplementing TGFβ2 or inhibiting the ERK/MAPK signalling pathway can reduce the appearance of VSMCs osteogenic phenotype. Our findings may present a novel therapeutic approach to prevent of vascular calcification after venous thrombosis.

An overview of in-stent restenosis in iliofemoral venous stents

BACKGROUND

Although endovenous stents have been associated with overall low morbidity, they can require reinterventions to correct stent malfunction due to in-stent restenosis (ISR). ISR has often occurred iliofemoral venous stents but has not been well described. It has been reported to develop in >70% of patients who have undergone iliofemoral venous stenting. We sought to provide an overview of ISR in iliofemoral venous stents, including the pathologic, diagnostic, and management considerations and the identification of several areas of potential research in the future.

METHODS

A search of reported English-language studies was performed in PubMed and the Cochrane Library. "In-stent restenosis," "vein," "venous," "iliac," and "iliofemoral" were used as keywords. The pertinent reports included in the present review had addressed the pathology, diagnosis, and current management options for ISR.

RESULTS

ISR refers to the narrowing of the luminal caliber of the stent owing to the development of stenosis inside the stent itself. ISR should be differentiated from stent compression. Two main types of ISR have been described: soft and hard lesions. These lesions respond differently to angioplasty. Stent inflow and shear stress are important factors in the development of ISR. The treatment options available at present include balloon angioplasty (hyperdilation or isodilation), laser ablation, atherectomy, and Z-stent placement.

CONCLUSIONS

Reintervention for ISR should be determined by the presence of residual or recurrent symptoms and not simply by a numeric value obtained from an imaging study. Overall stent occlusion due to ISR is rare, and no role exists for prophylactic angioplasty to treat asymptomatic ISR. The current treatment options for ISR are mostly durable and effective. However, more research is needed on methods to prevent the development of ISR. The role of antiplatelet and anticoagulant agents in the prevention of ISR requires further investigation, with particular attention to unique subset of patients (after thrombosis vs nonthrombotic iliac vein lesions). For high-risk, post-thrombotic patients, anticoagulation can be considered to prevent ISR. The role of triple therapy (anticoagulation and dual antiplatelet therapy) in the prevention of ISR remains unclear.

Histopathology of Iliocaval Venous In-Stent Restenosis Treated With Directional Atherectomy

Purpose: To report the use of directional atherectomy to treat venous in-stent restenosis (ISR) and subsequent histopathological analysis of retrieved intrastent tissue. Case Report: A 55-year-old man presented with recurrent symptoms of venous congestion following iliofemoral stenting. The stents were found to be occluded on imaging. Directional atherectomy was used to recanalize the iliofemoral venous stents, which provided significant symptom relief. Tissue retrieved from within the stent demonstrated patterns of cellular components similar to arterial ISR. At 6-month follow-up, the stents remain patent, with no evidence of further ISR. Conclusion: Directional atherectomy is a potential treatment option for iliofemoral venous ISR. The pathological process of venous ISR demonstrates cellular changes similar to arterial ISR.

[Stenting of calcified iliofemoral venous segment in post-thrombotic syndrome]

Stenting of the iliac veins in patients with post-thrombotic syndrome is an intervention associated with a low risk of complications, high primary and secondary patency rates, low incidence of restenosis, leading to a significant decrease in the severity of symptoms of chronic venous disease and a high rate of trophic ulcer healing, as compared with conservative therapy. Unlike subcutaneous veins, the formation of calcinates in deep veins after endured thrombosis is of considerably less frequent occurrence. Described in the article is a clinical case report concerning successful stenting of the iliofemoral venous segment in a female patient presenting with post-thrombotic syndrome, a trophic ulcer of the crus, and the presence of linear calcinosis in the lumen of the iliac veins and common femoral vein. This case report demonstrates the possibilities of contemporary endovenous techniques in treatment of this cohort of patients. Despite calcified segments, stenting was performed without technical obstacles and with a favourable clinical outcome. Such interventions may be regarded as justified and safe provided the operating surgeon has appropriate skill and experience.