It's estimated that 6 million people in the United States suffer from severe symptoms of chronic venous insufficiency (CVI). Up to 500,000 of these individuals have or will develop venous ulcers, which cause severe pain, limited mobility, absence from work, psychological stress, and exude an odor that can lead to social isolation of the patient. The annual healthcare cost associated with CVI is more than $1 billion in the United States and more than $650 million in the UK. Current treatments of CVI include surgical stripping and ligation of refluxing veins, sclerotherapy, and endovenous ablation. The current gold standard for treating CVI is endovenous ablation (EVA). However, recurrence rates as high as 32% have still been reported after EVA treatment. Other limitations of EVA are the complexity of the procedure, inability to be used in excessively tortuous or short vessels, and the procedural pain reported by patients. The proposed project outlines the development of a shape memory polymer (SMP) foam vascular occlusion device (VOD) to treat complications associated with CVI. The VOD will provide rapid, complete occlusion of the great saphenous vein with minimal risk of device dislocation, vessel rupture, and damage to surrounding tissue and nerves. The time required, and procedural difficulty, to complete endovenous ablation procedures will also be significantly reduced. Benchtop verification studies will be performed to ensure the proposed devices are stable at the treatment region under flow rates four times greater than what is typically seen in patients. Device migration from the treatment region will also be monitored when subjected to flexion and compression to mimic the conditions that would be seen in the peripheral vessels during ambulation and muscle contraction. Verification studies will also be performed to ensure no particulates are created during perfusion of the device. These studies will subject the VOD to various flow rates at body temperature for 30 minutes, and all perfused fluid containing any particulates will be collected in a collection basin The perfused fluid will then be strained through a 5m pore filter that will be subsequently analyzed via microscopy to determine compliance with the criteria dictated in USP <788>. Finally, the VOD will be delivered to a PDMS model of the great saphenous vein by a practicing interventional radiologist and vascular surgeon using conventional endovenous techniques and ultrasonography. The device will be evaluated for navigability, visualization, ease of use and deployment, and effectiveness in occluding the target vessel.
It is estimated that more than 6 million people in the United States suffer from severe complications associated with chronic venous insufficiency. These complications include pain, psychological stress, limited mobility, absence from work, and recurrent, open wounds in the legs, which account for approximately $1 billion in annual healthcare costs in the United States. The proposed technology addresses these complications by minimizing operation time and procedural difficulty, enhancing the long-term healing outcomes of chronic wounds, reducing patient pain, and extending the capabilities of minimally invasive treatments to include a larger population of individuals.
| Landsman, Todd L; Bush, Ruth L; Glowczwski, Alan et al. (2016) Design and verification of a shape memory polymer peripheral occlusion device. J Mech Behav Biomed Mater 63:195-206 |
