Addressing the Biocompatibility Issue of the Venous Stent

Vein narrowing or vein obstruction are conditions wherein a vein in our body is partially or completely impeded from allowing blood to flow through it, leading to a variety of complications, some merely discomforting (e.g., slight pain or swelling), but some fatal (e.g., stroke). One procedure used to resolve this condition is stenting, which is the insertion of a stent in the obstructed vein that is made of sturdy yet flexible material to open it up and allow resumption of normal blood flow.

Major concern on stenting

One major concern with regard to stenting is biocompatibility or the level of acceptance of stent (which is a foreign body) by the human body. The lower the biocompatibility, the more prone the human body will be to complications (e.g., restenosis, or the re-narrowing of the veins, and thrombosis, or the formation of blood clots).

Two approaches

There are two approaches to addressing the biocompatibility issue.

  • Use of materials with high biocompatibility. The most practical material to produce stents is stainless steel, but this material is relatively low in biocompatibility. Medication to prevent the body from “attacking” the foreign object is needed to prevent blood clot formation, which could lead to fatal complications, such as strokes. Materials that are more biocompatible are gold, tantalum, cobalt-chromium, and nickel-titanium (among others). However, these are also more expensive and/or follow a more difficult stent production process. The choice of materials would most likely depend on how bad the results of biocompatibility complications will be to the human body overall.
  • Use of bioabsorbable stents. There are now stents that are made of materials that are naturally absorbed by the body over a specified period of time to allow the vein to heal and/or normalize, and limit the time wherein medication is needed to inhibit the body from attacking the stent and forming potentially fatal blood clots. The limitation to these types of stents is one of longevity, i.e., it cannot be used for conditions that require a longer healing time.

Stenting is an effective medical procedure to restore the flow of blood to the veins and other body vessels. Care must be taken, however, those complications brought about by the biocompatibility level of the stent are likewise addressed.