Biomedical Textiles Are Opening the Door for Less Invasive Surgical Procedures

The incorporation of biomedical textiles in medical devices is enabling procedures across a wide range of surgical markets to be simpler and less invasive. A previous column (Jan./Feb. 2021) explored the opportunities for innovation via textiles for cardiovascular and orthopedic applications, and surgical robotics—these markets remain ripe for continued transformation. But other areas are increasingly being revolutionized by textiles, too, including general surgery, neurovascular procedures, sports medicine, and endoscopy. When biomedical textile engineers work closely with medical device OEMs, they can add a greater degree of innovation and efficacy to medical devices by creating structures better aligned with how the device needs to perform today, as well as how it must function in the body over time.

Why Consider Textile Components?
New methods of changing fabric density, pattern, or fiber orientation during design are resulting in complex textile structures that get closer to biomimicry than ever before. Desired properties such as porosity, radial expansion, compaction, and flexibility can be localized to specific regions of fabrics, thanks to the most modern textile forming equipment.

Inherent strength, flexibility, and biocompatibility make textiles ideal for integrating seamlessly into the human body while enabling physicians to use lower profile devices and less invasive surgical procedures. Textiles can be formed into many complex shapes and geometries with highly customized properties. Implantable textiles are also chemically inert, corrosion-proof, and offer favorable long-term performance.

Their characteristics make them ideally suited for applications including:

General Surgery
General surgery procedures related to treating ailments of the esophagus and related organs; abdomen; breast, skin, and soft tissue; and endocrine system continue to evolve. Medical device companies are increasingly bringing smaller, lower profile medical devices to market that support less invasive general surgery approaches, largely enabled by the incorporation of specialized biomedical textiles. The resulting surgical approaches have the potential to significantly improve overall patient outcomes, as well as reduce overall costs to the healthcare system. Patients undergoing minimally invasive surgery (MIS) generally report less post-surgical pain and more rapid recovery times than those treated with traditional open surgeries. The surgeons performing these MIS procedures often find them to be easier to perform and require less time in the operating room.

Biomedical textiles can successfully be integrated into OEMs’ devices thanks to the material properties and nearly unlimited shapes and geometries that engineered textile structures can provide. Used both internally and externally for general surgery, textiles have become an important part of soft tissue repair, powered irrigation surgery, topical hemostasis, organ transplants, catheter reinforcement, catheter steering, orthopedic implants, plastic surgery applications, and breast reconstruction. Today, textiles are used in sutures, pain pads, wound dressings, surgical meshes, tissue engineering scaffolds, abdominal wall patches, medical fabrics, breast lift slings, and more—and the possibilities are growing.

Neurovascular Procedures
Many traditional neurovascular procedures are highly invasive, with the potential for devastating side effects and long recovery times. For example, cerebral clipping—an invasive surgical procedure to close off an aneurysm by removing a section of the skull to access it—can lead to a perioperative stroke.¹

Fortunately, the incorporation of implantable biomedical textile components is now allowing neurovascular medical devices to be smaller, lower profile, compressible, and flexible enough to be adeptly guided through the complex yet delicate network of blood vessels in the head and neck, while still able to perform their critical function. Textiles are proving well-suited for applications such as intracranial aneurysm repair and occlusion, flow diversion, ischemic clot retrieval/thrombus retrieval, neurostenting, nerve regeneration, and as sheaths for peripheral nerve conduits.

When it comes to neurovascular procedures, textiles allow for much less invasive surgical approaches and lower profile delivery systems leveraging micro-catheters. Braided, woven, and knitted biomedical textiles are helping to improve patient outcomes with less invasive approaches to treating aneurysms and brain hemorrhages; preventing ischemic strokes by removing debris in the vessels; and removing thrombus after a stroke.

Textiles incorporating metal alloys such as Nitinol are ideal for neurovascular devices due largely to two unique properties: shape memory effect and superelasticity. Shape memory allows nitinol to undergo deformation at one temperature, stay in its deformed shape when the external force is removed, then recover its original shape upon heating above its “transformation temperature.”

Superelasticity means it can undergo large deformations and immediately return to its undeformed shape upon removal of the external load.

Sports Medicine
Sports and other physical activities contribute to many injuries annually. Since patients being treated for sports injuries are often young and enjoy engaging in physical activities, when treating them, it is a high priority to restore and preserve their range of motion and natural movement. Less invasive sports medicine procedures can mean shorter recovery times and better outcomes. To support these minimally invasive procedures, medical device OEMs are increasingly innovating by incorporating braided, woven, or knitted biomedical textile structures into their products’ design.

From soft tissue tears to bone grafts to spinal stabilization, biomedical textiles are now frequently part of sports medicine procedures. Examples include tendon and ligament repair (especially when it comes to the treatment of Achilles and ACL injuries), acromioclavicular (AC) joint fixation, bone anchors, shoulder/rotator cuff repair, suture reinforcement patches, load sharing tethers, knee ligament repair, and foot and ankle injury repair. Textiles are also used to treat PCL (posterior cruciate ligament), MCL (medial collateral ligament), LCL (lateral collateral ligament), knee meniscus (lateral and medial), articular cartilage replacement, ankle/suture-based and extra-cortical fixation buttons, and injuries of the bicep and quadricep.

Braided textiles have a low profile and high tensile strength, allowing a surgeon to secure soft and bony tissue. Recent technology advancements allow for greater customization of braided textile properties (such as variable density) to facilitate a simpler and more durable surgical repair. Woven and knitted biomedical textile structures have also become increasingly sought after as foundations for implants and anchor points for attaching soft tissue due to their strength, compliance, and inherent capabilities for promoting tissue ingrowth.

Artificial ligaments can be made of a multilayered or tubular woven structure having intra-region, at least one bend region, and end regions.² These textile structures can distribute load over a larger surface area and be engineered to mimic the behavior of the ruptured tendons and ligaments they are replacing.

Endoscopy
Significant growth of the North American endoscopy market is driven largely by an increasing number of gastrointestinal tract disorders and rising awareness of endoscopy devices that allow for smaller incisions than open surgery. Devices used in procedures such as colonoscopies and upper GI endoscopies enable the surgeon to see inside the body with a video camera attached to a flexible, low-profile tube inserted non-surgically or through a small incision. The surgeon is then able to use tiny surgical instruments while seeing the organs on a computer monitor in real-time. These procedures often result in less scarring, quicker recoveries, and less risk of complications from infection or blood loss.

Biomedical textiles are proving to be an excellent replacement for wire and metal components in many endoscopic devices, such as for the flexible cable that goes inside the tube to deploy or steer a catheter during teleoperated endoscopic treatment. Textiles have much more compliant properties than metals in terms of torque, flexibility, and strength. Incorporating textiles provides medical device OEMs maximum flexibility for the design of their endoscopy innovations.

Textiles can conform to anatomical curves and bends. They also have a lower coefficient of friction, enabling smoother glide and more degrees of freedom and orientation. This is particularly important given the nature of endoscopic procedures. Textiles are smaller, thinner, and stronger than traditional metal, while also being MRI-safe. Braided textiles can bear significant weight and have customizable dimensional measurements. A cylindrical shape, for example, can make them well-suited to wind through complex areas such as the digestive tract, or to conform to twists and turns. They may also be incorporated into surgical robotics systems and used to deploy and steer an endoscopic catheter.

Conclusion
Biomedical textiles have many properties that can allow medical device OEMs to create smaller, lower profile devices to enable less invasive procedures. Textiles are inherently compressible and flexible, so they are excellent for less invasive delivery applications that benefit from shape transformation (i.e., entering through a small hole and then expanding in the body). They are also highly compatible with biologic structures and can be tailored to the needs of the procedure. By working in close collaboration, OEMs and their textile partners stand to revolutionize the way surgeries across many applications are approached. 

References

1. bit.ly/mpo220391
2. bit.ly/mpo220392