Conservative treatment vs thrombus removal for Iliofemoral vein thrombosis in patients with congenital abnormalities of the inferior vena cava: a case report and systematic review of the literature

Deep venous thrombosis in patients with atresia of the inferior vena cava and right kidney hypoplasia (KILT syndrome): Systematic review of the literature

Inferior vena cava (IVC) anomalies are uncommon congenital causes of deep vein thrombosis (DVT). KILT syndrome (kidney and IVC abnormalities with leg thrombosis) has only been described as case reports in the literature. Therefore, the characteristics, evaluation, and management of patients with KILT syndrome have not yet been standardized. This study aimed to systematically review and analyze the clinical and radiographic data and treatment of previously reported cases of KILT syndrome. In this systematic review, we performed a literature search of the PubMed, Scopus, and Web of Science databases in December 2023, with no restrictions on the publication date. After duplicate extractions, 4195 articles were screened. Case reports and case series reporting on KILT syndrome were included. In addition to previously published cases, we included a new case of a previously healthy 25-year-old man with KILT syndrome in the analysis. A total of 34 cases were therefore included in this study. The majority (76.5%) were male patients with a median age of 24 years. In most patients, unprovoked bilateral iliofemoral thrombosis was diagnosed, and 64.7% had left kidney abnormalities. Our study suggests that anomalies of the IVC should be suspected in all young patients, especially male patients, with proximal, recurrent, or idiopathic DVT. If an IVC anomaly is confirmed, the kidneys should be examined to monitor and preserve healthy kidneys in cases of KILT syndrome. The data collected from all patients emphasize the requirement of long-term anticoagulation and risk factor control. Surgical measures may be effective for treating symptomatic refractory cases.

Mechanism of effect of stenting on hemodynamics at iliac vein bifurcation

When performing stent intervention for iliac vein compression syndrome, the operator selects the appropriate stent and determines its implantation depth according to the type and severity of iliac vein stenosis in the patient. However, there is still uncertainty regarding how the structure of the stent and its implantation depth affect hemodynamics at the site of lesion. In this paper, we analyzed three commonly used stents (Vena stent from Venmedtch, Venovo from Bard, and Smart stent from Cordis) with different implantation depths (0, 10, 20 mm) using computational fluid dynamics (CFD). We focused on evaluating hemorheological parameters such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), etc., within one pulsatile cycle after stent implantation. The correlation between geometric parameters of the stents and hemodynamic indicators was assessed using Pearson correlation coefficient (r), which was further validated through PIV velocity measurement experiment. The results revealed that an increase in implantation depth led to a more pronounced disturbance effect on blood flow at bifurcation for densely arranged support body-type stents. This effect was particularly significant during periods of smooth blood flow. On the other hand, crown-shaped Vena stents exhibited relatively less disruption to blood flow post-implantation. Implantation depth showed a strong negative correlation with TAWSS but a strong positive correlation with OSI and RRT. These findings suggest an increased risk of thrombosis at iliac vein bifurcation following stent placement. Amongst all three tested stents, Vena Stent demonstrated more favorable periodic parameters after implantation compared to others. These results provide valuable theoretical insights into understanding contralateral circulation thrombosis associated with iliac vein stenting.