The application of inferior vena cava filters in orthopaedics and current research advances

Optimizing inferior vena cava filter design: A computational fluid dynamics study on strut configuration for enhanced hemodynamic performance and thrombosis reduction

Background and objective

Inferior vena cava filters have been shown to be effective in preventing deep vein thrombosis and its secondary complication, pulmonary embolism, thereby reducing the high mortality rate. Although inferior vena cava filters have evolved, specific complications like inferior vena cava thrombosis-induced deep vein thrombosis worsening and recurrent pulmonary embolism continue to pose challenges. This study analyzes the effects of geometric parameter variations of inferior vena cava filters, which have a significant impact on the thrombus formation inside the filter, the capture, dissolution, and hemodynamic flow of thrombus, as well as the shear stress on the filter and vascular wall.

Methods

This study used computational fluid dynamic simulations with the carreau model to investigate the impact of varying inferior vena cava filter design parameters (number of struts, strut arm length, and tilt angle) on hemodynamics.

Results

Recirculation and stagnation areas due to flow velocity and pressure, along with wall shear stress values, were identified as key factors. It is important to find a balance between wall shear stress high enough to aid thrombolysis and low enough to prevent platelet activation. The results of this paper show that the risk of platelet activation and thrombus filtration may be lowest when the wall shear stress of the filter ranges from 0 to 4 [Pa], minimizing stress concentration within the filter.

Conclusion

16 arm struts with a length of 20 mm and a tilt angle of 0° provide the best balance between thrombus capture and minimization of hemodynamic disturbance. This configuration minimizes the size of the stagnation and recirculation zones while maintaining sufficient wall shear stress for thrombus dissolution.

Laparoscopic-assisted retrieval of inferior vena cava filter: A case report and literature review

BACKGROUND

The retrieval of inferior vena cava filters beyond the retrieval window poses challenges, requiring alternative techniques.

OBJECTIVES

To discuss the laparoscopy-assisted retrieval approach for difficult inferior vena cava filters.

RESEARCH DESIGN

Case report.

SUBJECTS

A 57-year-old male with a retrievable inferior vena cava filter placed 8 months prior.

MEASURES

Laparoscopy-assisted retrieval technique utilized after unsuccessful interventional attempts.

RESULTS

Successful retrieval of the filter despite thickened intimal tissue involvement, with no postoperative complications.

CONCLUSIONS

Laparoscopy-assisted retrieval offers a direct visual approach for challenging filter removal, proving minimally invasive, safe, and effective.

Application of the Double Series Filter Technique for the Treatment of Acute Inferior Vena Cava Filter-Mediated Thrombosis

BACKGROUND

In this study, we examined the safety and effectiveness of removing inferior vena cava (IVC) filters with residual acute thrombosis after endovascular therapy.

METHODS

A retrospective chart review of 712 patients who underwent retrievable IVC filter implantation between July 2018 and December 2022 was conducted. Residual thrombosis with the IVC filter occurred in 18 patients, and the volume of residual acute thrombosis in the IVC filter exceeded 1 mL in all cases. Angiography was performed to evaluate the size of the residual thrombosis and its position with respect to the filter. The double series filter technique (first filter, infrarenal IVC filter; second filter, suprarenal IVC filter) was used to remove the filter and thrombosis. We summarize the diagnosis, treatment, and surgical experience of these patients.

RESULTS

In this study, 16 of 18 patients (88.9%) demonstrated residual thrombosis in the IVC filter. One patient (5.6%) demonstrated thrombosis located both inside and floating above the filter, and one patient (5.6%) demonstrated thrombosis located both inside and underneath the filter. The technical success rate of double series IVC filter retrieval was 100%. Seventeen patients (94.4%) underwent single-stage suprarenal IVC filter retrieval, and one patient (5.6%, 1/18) underwent two-stage retrieval. In terms of residual thrombosis removal, 14 patients (77.7%) achieved complete removal and 4 patients (22.3%) achieved partial removal. Residual thrombosis could not be removed through the sheath in one patient, so femoral vein thrombectomy was performed. No other procedure-related complications were observed. The median follow-up time was 22.5 ± 6.8 months. No recurrence of thrombus symptoms was reported, and B ultrasound and computed tomography demonstrated smooth blood flow in the IVC, renal veins, and pulmonary artery.

CONCLUSIONS

For patients with residual acute thrombosis on the IVC filter and in whom there was absence of a more appropriate treatment after percutaneous mechanical thrombectomy or catheter-directed thrombolysis therapy, the double series IVC filter technique was a safe approach to improve the IVC filter retrieval rate in the early stage, as well as for simultaneous residual thrombus removal.