In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.

Prosthetic venous valves for chronic venous insufficiency:Advancements and future design directions

With the serious aging population and lifestyle changes,chronic venous insufficiency accounts for approximately 25.95%of the population,which may lead to lower limb edema and leg heaviness,as well as severe infections of skin ulcers that can result in sepsis and necessitate amputation.Conservative treatment and other supportive measures can only slow the disease's progression but are unable to drastically reverse it;surgical interventions are rarely used due to the high risk of catastrophic postoperative consequences.As one of the most promising minimally invasive therapies,percutaneous prosthetic valve replacement has emerged in light of this situation,providing novel alternatives for patients with deep venous valve insufficiency.We reviewed the historical prosthetic venous valve designs,including their structure and materials,animal evaluation models,and assessment criteria.On the basis of the findings from in vitro tests,animal studies,and clinical trials,we summarized the major challenges and potential solutions for the development of advanced prosthetic venous valves.