A medical mesh tube is an implantable device used to provide structural support or create a conduit within the human body. These devices are generally constructed from synthetic materials, often woven or extruded into a flexible, porous scaffold. Their design allows them to be deployed in various anatomical locations to restore function or reinforce weakened tissue structures. Applications range from small-scale interventions in coronary arteries to large-scale reconstruction of major blood vessels.
Maintaining Patency in Blood Vessels
One of the most common applications of medical mesh tubes is as vascular stents, which are small, expandable scaffolds placed inside a narrowed artery to restore proper blood flow. This procedure is frequently performed in the coronary arteries to treat blockages caused by atherosclerosis, where plaque restricts the vessel’s diameter. The stent provides mechanical support, exerting radial force against the vessel wall to prevent it from collapsing or recoiling after balloon angioplasty.
The earliest versions were bare metal stents (BMS), but their effectiveness was often limited by restenosis, the re-narrowing of the artery. Drug-eluting stents (DES) feature a polymer coating that slowly releases an antiproliferative medication, such as sirolimus or paclitaxel. These drugs inhibit the smooth muscle cell proliferation that leads to neointimal hyperplasia, significantly reducing the likelihood of re-blockage. Mesh tubes are also routinely used in peripheral arteries to maintain patency and treat peripheral artery disease.
Repairing and Replacing Major Arteries
Mesh tubes are engineered to repair or replace damaged sections of large-diameter blood vessels. These larger devices, known as vascular grafts or stent-grafts, are used when an artery is compromised by disease or trauma, such as an aneurysm. Open surgical repair traditionally involves excising the damaged segment and replacing it with a fully synthetic woven tube.
A less invasive approach, endovascular aneurysm repair (EVAR), utilizes a stent-graft, which is a fabric tube supported by a metal mesh frame. This device is delivered through small incisions in the groin and deployed within the damaged artery. Once positioned, the stent-graft effectively lines the diseased section, diverting blood flow through the synthetic conduit and excluding the weakened aortic wall from the high-pressure circulation. For complex aneurysms near branch vessels, specialized bifurcated or fenestrated (windowed) endografts are used to ensure blood flow is preserved to critical arteries like those supplying the kidneys.
Materials and Design of Medical Mesh Tubes
The selection of material is dictated by the device’s intended function, balancing the need for mechanical strength with biocompatibility. Stents require materials with high radial strength and flexibility, using metallic alloys like stainless steel or Nitinol. Nitinol, a nickel-titanium alloy, is valued for its superelasticity and shape memory, allowing the stent to self-expand once deployed at body temperature.
Conversely, larger vascular grafts and endografts often incorporate durable polymeric fabrics, such as expanded polytetrafluoroethylene (ePTFE) or Dacron (a type of polyester). These materials are chosen for their long-term biostability and ability to be woven into a compliant tube that can be sutured into place or incorporated into a stent frame. Bioresorbable mesh tubes are also used; these are made from polymers that dissolve over a predictable period, leaving behind a healed vessel and eliminating the risk of long-term scaffold complications.