Nitinol is a nickel-titanium alloy known for its shape memory and superelastic properties. Due to these unique properties, Nitinol is widely used in medical devices. From stents to filters, Nitinol enables the manufacture of minimally invasive surgical tools that can improve patient outcomes.

Nitinol Stents

Probably the most familiar Nitinol medical device is the coronary stent. Made from Nitinol wire mesh tubing, stents help reopen blocked arteries and improve blood flow to the heart. During insertion through a catheter, the stent can be compressed into a narrow shape. But due to its shape memory property, it regains its original tubular form once placed in the artery, holding it open indefinitely.

Over the last few decades, millions of patients have benefited from drug-eluting stents that prevent reblockage of arteries. Made from Nitinol embedded with medication, these deliver drugs locally to inhibit scar tissue formation. Newer bioabsorbable stents are now being manufactured from Nitinol and polymers. They dissolve harmlessly after holding the artery open long enough for natural healing.

Other Types of Stents

Besides coronary applications, Nitinol Medical Devices stents are used in numerous other areas. For example, tracheobronchial stents help reopen collapsed airways in conditions like cancer or tuberculosis. Biliary stents drain blocked bile ducts, resolving jaundice issues. Ureteral stents relieve kidney stone-related ureter obstruction. Vena cava filters made of Nitinol mesh trap blood clots from moving to the lungs. Renal and cerebral aneurysm stents reinforce weakened arterial walls.

Filters and Basket Devices

Another major category of Nitinol medical devices are filters and basket retrieval systems. Inferior vena cava filters trap blood clots in the vein before they reach the heart or lungs. Made of self-expanding Nitinol mesh, these removable devices are placed percutaneously for short-term use in high-risk patients.

Nitinol baskets are used to retrieve all kinds of objects unintentionally ingested or placed in the body. From biopsy forceps to stents accidentally released in vessels—these shapeable baskets can grab items safely under imaging guidance. Nitinol stone baskets extract kidney and gallbladder stones through minimally invasive procedures.

Guidewires and Catheters

Being highly flexible yet kink-resistant, Nitinol is an ideal material for guidewires used in catheter-based surgeries and imaging procedures. From 0.010 inch coronary guidewires to larger infusion catheters—their superelastic property allows deep intubation through tortuous vessels.

Catheters tipped with steerable Nitinol coils enable precise navigation through branching vessels to target lesions accurately. Balloon catheters coated over Nitinol stents facilitate their delivery and deployment in arteries. Micro coaxial catheters employ Nitinol for super selective access during neuro and transplantation surgeries.

Bone Fracture Fixation

Orthopedic applications leverage Nitinol’s bending memory effect and corrosion resistance. Shape memory bone plates and screws exactly match contour of fractures to provide stable internal fixation. Nitinol implants reduce need for hardware removal post healing. Kirschner wires guide pinning of fractured fragments into proper position, while Nitinol hip prosthesis stems prevent loosening over years.

Future Prospects

Ongoing research utilizes nanotechnologies and additive manufacturing to produce next-gen Nitinol bioimplants. Newer alloy compositions aim to custom design superelasticity parameters as per application needs. Besides vascular uses, industries are studying potential of Nitinol in wound closure devices, artificial muscles and organs printing. With its versatile functionalities translating well, Nitinol will continue shaping medical innovations and improving lives worldwide.

As evident from its increasing use in minimally invasive tools ranging from stents to catheters, Nitinol is a revolutionary metallic biomaterial. Leveraging shape memory and superelastic characteristics in novel ways, engineers are expanding Nitinol’s scope. This alloy promises to enhance surgical outcomes while reducing recovery time across therapeutic areas. With further alloy optimization and manufacturing advancements, expect Nitinol devices to usher unprecedented changes in medicine.

Get more insights on this topic: Nitinol Medical Devices