MSI Stent Securement Testing Overview

Summary

In this presentation, Melissa Lockwitzer from Machine Solutions discusses the importance of stent securement testing for patient safety and regulatory compliance. She compares three methods—shim, tape, and the MSI SR-1000—evaluating their ease of setup, operation, and data consistency. The SR-1000 stands out for its automation, precision, and reduced variability in results. Lockwitzer highlights how the SR-1000 offers more consistent and efficient testing than traditional methods, emphasizing its advantages in improving stent testing practices. The presentation also includes a demonstration of the SR-1000 in action.

Takeaways

• 🩺 The presentation is by Melissa Lockwitzer, focusing on stent securement testing methods and their importance.
• 🏥 Stent securement testing is crucial for patient safety and is required by the FDA to ensure that stents reach the intended treatment site without issues.
• ⚙️ Three different stent securement methods are compared: the shim method, the tape method, and the SR-1000 by MSI.
• 🔧 The SR-1000 is the most automated of the three methods, launched last year by Machine Solutions (MSI), and features segmental compression technology.
• 📊 The tape method shows the highest standard deviation and requires significant setup time, often leading to misleadingly high retention forces.
• 📉 The SR-1000 had the lowest standard deviation (0.06 lbs) and the most consistent results in terms of stent securement forces.
• ⏳ Setup time comparison: The tape method takes over 6 minutes, the shim method takes around 3 minutes, and the SR-1000 takes only 1 to 1.5 minutes.
• 🔍 The SR-1000 integrates a video system that links to the test data, helping to identify the exact moment of stent dislodgement.
• 📐 The SR-1000 also provides control over diameter and force, minimizing operator variability and ensuring a more accurate stent securement test.
• 🚀 The conclusion suggests that the longstanding belief about minimum retention forces may be based on the outdated tape method and should be reconsidered.

Q & A

What is the primary purpose of stent securement testing?

The primary purpose of stent securement testing is to ensure that balloon-expandable stents are securely crimped onto the delivery system, making sure they reach the intended treatment site safely and function effectively. This testing is crucial for patient safety, as failure to secure the stent can result in serious complications, including prolonged procedures or even open-heart surgery.

What are the three failure modes discussed in the presentation?

The three failure modes discussed are: 1) Straight dislodgement, where the stent moves outside the proximal and distal marker bands, causing issues with deployment. 2) Stent compression or buckling, which can cause vessel damage or perforation. 3) Complete dislodgement of the stent, where it detaches from the delivery system and can lead to severe complications such as the need for open-heart surgery.

What are the three methods of stent securement testing compared in the presentation?

The three methods compared in the presentation are: 1) The shim method, which uses stainless steel shims and an Instron tensile tester. 2) The tape method, which uses adhesive tape to secure the stent. 3) The MSI SR-1000 method, which utilizes segmental compression technology for more automated and controlled testing.

What are some of the challenges associated with the shim method?

Some challenges with the shim method include difficulties with sample alignment. If the sample isn't perfectly straight, axial angulation can result in higher stent securement forces that are not indicative of the actual securement. Additionally, different-sized shims are required for various stent and balloon sizes, adding complexity to the setup.

Why does the tape method yield the highest securement forces?

The tape method yields the highest securement forces because the tape often adheres to the balloon underneath the stent in addition to the stent itself. This adhesion increases the perceived securement forces, even though it may not accurately reflect the actual securement of the stent on the balloon.

What are the key advantages of the MSI SR-1000 over the other methods?

The key advantages of the MSI SR-1000 include a more automated setup that reduces operator variability, the ability to control both the diameter and force applied to the balloon, and a shorter setup time of around one to one and a half minutes per sample. It also provides more consistent and accurate data with lower standard deviation compared to the other methods.

How does the SR-1000 system ensure accurate stent securement testing?

The SR-1000 system ensures accuracy through its segmental compression technology, which grips the catheter and balloon with precise radial force. It controls both the diameter and the force applied to ensure consistent and linear alignment of the sample, eliminating side axial loading that can skew results. The system is also fully PC-controlled, minimizing operator error.

What were the findings regarding the standard deviation of the securement forces for each method?

The tape method had the highest standard deviation (0.36 pounds), indicating significant variability in the results. The shim method had a lower standard deviation (0.1 pounds), while the MSI SR-1000 had the smallest standard deviation (0.06 pounds), showing that it produced the most consistent and reliable results.

Why is the video system integrated into the SR-1000 system beneficial?

The video system integrated into the SR-1000 is beneficial because it allows operators to visually confirm the moment the stent starts to dislodge. This feature is linked to the data in real-time, ensuring accurate identification of the initial dislodgement point, which helps when analyzing forces and ensuring precise testing.

What conclusion was drawn about the commonly accepted minimum retention force of 0.5 to 1 pound?

The presentation concludes that the long-standing notion of a minimum retention force of 0.5 to 1 pound may be based on the tape method, which produces artificially high securement forces. This standard should not necessarily be applied to other methods, like the MSI SR-1000 or the shim method, which provide more accurate measures of stent securement.