First-in-human study of the CAPTIS embolic protection system during transcatheter aortic valve replacement.

BACKGROUND: Stroke and other clinically significant embolic complications are well documented in the early period following transcatheter aortic valve replacement (TAVR). The CAPTIS device is an embolic protection system, designed to provide neurovascular and systemic protection by deflecting debris away from the brain's circulation, capturing the debris and thus avoiding systemic embolisation. AIMS: We aimed to study the safety and feasibility study of the CAPTIS complete cerebral and full-body embolic protection system during TAVR. METHODS: A first-in-human study investigated the safety, feasibility and debris capturing ability of CAPTIS during TAVR. Patients were followed for 30 days. The primary endpoints were device safety and cerebrovascular events at 72 hours. RESULTS: Twenty patients underwent TAVR using balloon-expandable or self-expanding valve systems. CAPTIS was successfully delivered, positioned, deployed, and retrieved in all cases, and TAVR was successfully completed without device-related complications. No cerebrovascular events were observed. High numbers of debris particles were captured in all patients. CONCLUSIONS: The use of the CAPTIS full-body embolic protection system during TAVR was safe, and it captured a substantial number of debris particles. No patient suffered from a cerebrovascular event. A randomised clinical trial is warranted to prove its efficacy.

Long-term evaluation of a compliant cushion form acetabular bearing for hip joint replacement: a 20 million cycles wear simulation.

Soft bearing materials that aim to reproduce the tribological function of the natural joint are gaining popularity as an alternative concept to conventional hard bearing materials in the hip and knee. However, it has not been proven so far that an elastic cushion bearing can be sufficiently durable as a long term (∼20 years) articulating joint prosthesis. The use of new bearing materials should be supported by accurate descriptions of the implant following usage and of the number, volume, and type of wear particles generated. We report on a long-term 20 million cycle (Mc) wear study of a commercial hip replacement system composed of a compliant polycarbonate-urethane (PCU) acetabular liner coupled to a cobalt-chromium alloy femoral head. The PCU liner showed excellent wear characteristics in terms of its low and steady volumetric wear rate (5.8-7.7 mm(3)/Mc) and low particle generation rate (2-3 × 10(6) particles/Mc). The latter is 5-6 orders of magnitude lower than that of highly cross-linked polyethylene and 6-8 orders of magnitude lower than that of metal-on-metal bearings. Microscopic analysis of the implants after the simulation demonstrated a low damage level to the implants' articulating surfaces. Thus, the compliant PCU bearing may provide a substantial advantage over traditional bearing materials.

Wear rate evaluation of a novel polycarbonate-urethane cushion form bearing for artificial hip joints.

There is growing interest in the use of compliant materials as an alternative to hard bearing materials such as polyethylene, metal and ceramics in artificial joints. Cushion form bearings based on polycarbonate-urethane (PCU) mimic the natural synovial joint more closely by promoting fluid-film lubrication. In the current study, we used a physiological simulator to evaluate the wear characteristics of a compliant PCU acetabular buffer, coupled against a cobalt-chrome femoral head. The wear rate was evaluated over 8 million cycles gravimetrically, as well as by wear particle isolation using filtration and bio-ferrography (BF). The gravimetric and BF methods showed a wear rate of 9.9-12.5mg per million cycles, whereas filtration resulted in a lower wear rate of 5.8mg per million cycles. Bio-ferrography was proven to be an effective method for the determination of wear characteristics of the PCU acetabular buffer. Specifically, it was found to be more sensitive towards the detection of wear particles compared to the conventional filtration method, and less prone to environmental fluctuations than the gravimetric method. PCU demonstrated a low particle generation rate (1-5×106 particles per million cycles), with the majority (96.6%) of wear particle mass lying above the biologically active range, 0.2-10µm. Thus, PCU offers a substantial advantage over traditional bearing materials, not only in its low wear rate, but also in its osteolytic potential.