The human body consists of many passages and conduits, which carry elements such as blood, urine, secretions, food and sometimes even air. Due to different reasons, these conduits can become narrow and may cause impairment to the flow. Because of advanced medical sciences, correction or prevention of such narrowing using an artificial conduit is possible. In medicine, such artificially produced conduits are termed as, ‘stents’.
Nature of a stent:
A stent is a barrel shaped lattice that usually made out of metal. It is rigid and strong enough to keep the walls of a conduit wide apart and therefore alleviating the possibility of a collapse following the dilatation of a narrowed segment. Although most of the stents are made of bare-metal, there are instances where a special form of fabric will give support to the metallic structure. Some stents are impregnated with medicines, which will prevent a possible blockage requiring stent replacement. These stents are also known as ‘drug-eluting’ stents because of its continuous release of a medicine in to its passage. Apart from the above, there can be different types of stents produced by different manufacturers available in the market.
Use of stents:
The main use of stents in medicine will be in relation to heart and its arteries. Stent placement or ‘angioplasty’ procedure is a frequently performed intervention in order to relieve coronary artery blockage. This can prevent an ischemic event related to heart muscles and therefore the life of a susceptible patient. However, many do not realize that, the uses of stents are not limited to cardiac interventions.
Non-cardiac uses of stents:
One of the non-cardiac uses of stents is in relation to maintaining patency of the ureters that drain urine from the kidneys in to the urinary bladder. When there is a risk of damage to the kidneys due to obstructed flow at the level of ureters, this procedure is performed to regain the patency and some of the other complications associated with such obstruction.
Prostate enlargement is another instance where there is a potential for using a stent. In such patients, the enlarged prostate may compress the prostatic part of the urethra and a stent can be placed to maintain its patency and therefore to relieve the symptoms shown by such patients.
Similar to coronary artery blockage, some of the other arteries supplying different organs can also get narrowed and compromised. One such artery is the arteries leading to the kidneys and reliving a possible renal artery obstruction could be life saving when thinking about the possible complications that may arise following a kidney failure. In certain instances, peripheral arteries supplying skin, muscles and limbs can also become narrow thus requiring placement of a stent to re-perfuse the affected region adequately.
Use of stents to prevent the extension of an aortic aneurysm is another life saving procedure performed using these devices. Fabric stents or ‘graft stents’ are used for this procedure and will provide resilience to the aortic wall to sustain pressures from the blood flow.
Biliary stents are the stents used to maintain flow of bile within the biliary tree extending from the liver. Similarly, pancreatic stents will allow flow of pancreatic juices in to the intestine if there is a segment of obstruction in its passageways.
Apart from the types of stents mentioned above, there can be other types suitable to use at different locations in the body. However, one should realize that placement of a stent might be either temporary or permanent depending on the nature of the intervention and the condition of the patient.