Stent

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For people named Stent, see Stent (surname).
Stent
Intervention
Blausen 0034 Angioplasty Stent 01.png
3D rendering of a stent in a coronary artery
MeSH D015607
MedlinePlus 002303

In medicine, a stent is a tube or other device placed in the body to create a passage between two hollow spaces, and stenting is the placement of such a stent. There are a wide variety of stents used for different purposes, from expandable coronary, vascular and billiary stents, to simple plastic stents used to allow the flow of urine between kidney and bladder. Stent is also used as a verb to describe the placement of such a device, particularly when a disease such as atherosclerosis has pathologically narrowed a structure such as an artery.

Stent types[edit]

Type and description Illustration
Coronary stents are placed during a percutaneous coronary intervention, also known as angioplasty. The most common use for coronary stents is in the coronary arteries, into which a bare-metal stent, a drug-eluting stent, a bioabsorbable stent, a dual-therapy stent (combination of both drug and bioengineered stent), or occasionally a covered stent is inserted.
A coronary stent
Vascular stents are commonly placed as part of peripheral artery angioplasty. Common sites treated with peripheral artery stents include the carotid, iliac, and femoral arteries. Because of the external compression and mechanical forces subjected to these locations, flexible stent materials such as nitinol are used in a majority of peripheral stent placements.[1]
Compressed and expanded peripheral artery stents
A stent graft or covered stent is type of vascular stent with a fabric coating that creates a contained tube but is expandable like a bare metal stent. Covered stents are used in endovascular surgical procedures such as endovascular aneurysm repair. Stent grafts are also used to treat stenoses in vascular grafts and fistulas used for hemodialysis.
Example of a stent used in an endovascular aneurysm repair
Ureteral stents are used to ensure the patency of a ureter, which may be compromised, for example, by a kidney stone. This method is sometimes used as a temporary measure to prevent damage to a blocked kidney until a procedure to remove the stone can be performed.
Example of a uretal stent used to alleviate hydronephrosis of the kidney
Prostatic stents are places from the bladder through the prostatic and penile urethra to allow drainage of the bladder through the penis. This is sometimes required in benign prostatic hypertrophy.
Example of a stent / catheter used in the prostate to treat an enlarged prostate and provide relief in cases of obstructed urination
Esophageal stents are a palliative treatment for advanced esophageal cancer.
Biliary stents provide bile drainage from the gallbladder, pancreas and bile ducts to the duodenum in conditions such as ascending cholangitis due to obstructing gallstones.
Endoscopic image of a biliary stent seen protruding from the ampulla of Vater at the time of duodenoscopy
Glaucoma drainage stents are recent developments and are awaiting approval in some countries. They are used to reduce intraocular pressure by providing a drainage channel.
Other types are duodenal stents, colonic stents, and pancreatic stents, the designations referring to the location of their placement.

Overuse[edit]

In 2007 the New England Journal of Medicine published the results of a trial called COURAGE.[2] The trial gave recommendations about the practice of stenting in PCI, a heart intervention.[2] This study was recognized as strong evidence for the need for a field-wide change in practice.[3][4][5]

Medical societies recommend that surgeons not perform stenting in the usual surgery of otherwise healthy individuals during percutaneous coronary intervention.[6][7] A report by the Chicago Tribune also noted that the use of cardiac coronary artery stents was too high in cases where the patient was in at least stable condition and the coronary artery stent(s) was implanted on an elective basis—many times more than one is implanted in the same procedure, even in the same vessel. However, the report was careful to note that they are indisputably still a viable therapy that often produces satisfactory results for those with acute coronary artery disease, such as relief of an arterial occlusion that has caused a heart attack (myocardial infarction), or where there is a danger of a piece of the blockage detaching and traveling (a thrombosis) to occlude a vessel in the cardiopulmonary system or the brain.[8]

Etymology[edit]

The origin of the word "stent" remains unsettled. The verb form "stenting" was used for centuries to describe the process of stiffening garments (a usage long obsolete, per the Oxford English Dictionary) and some believe this to be the origin. According to the Merriam Webster Third New International Dictionary, the noun evolved from the Middle English verb stenten, shortened from extenten, meaning to stretch, which in turn came from Latin extentus, past participle of extendere, to stretch out. Others attribute the noun "stent" to Jan F. Esser, a Dutch plastic surgeon who in 1916 used the word to describe a dental impression compound invented in 1856 by the English dentist Charles Stent (1807–1885), whom Esser employed to craft a form for facial reconstruction. The full account is described in the Journal of the History of Dentistry.[9] According to the author, from the use of Stent's compound as a support for facial tissues evolved the use of a stent to hold open various bodily structures. The first (self expanding) "stents" used in medical practice in 1986 by Ulrich Sigwart in Lausanne were initially called "Wallstents". Julio Palmaz et al. created a balloon expandable stent that is currently used.[10]

History[edit]

The first use of a coronary stent is typically attributed to Jacques Puel and Ulrich Sigwart when they implanted a stent into a patient in Toulouse, France in 1986.[11] It was used as a scaffold to prevent the vessel from closing and to avoid restenosis in coronary surgery - a condition where scar tissue grows within the stent and interferes with vascular flow. Shortly thereafter in 1987, Julio Palmaz (known for patenting a balloon-expandable stent) and Richard Schatz implanted their a similar stent into a patient in Germany. The use of these bare-metal stents helped reduce the incident of restenosis from 30-40% in coronary surgery to 20-30%.

Though many doctors have created the stent, the first FDA approved stent was invented by Gary S. Roubin.[citation needed]

To further reduce the incidence of restenosis, drug-eluting stents (DES) were introduced which consisted of stents coated in anti proliferative agents. Animal studies and later clinical trials showed a reduction in restenosis to approximately 5%.

See also[edit]

References[edit]

  1. ^ Vogel, T; Shindelman, L.; Nackman, G.; Graham, A. (2003). "Efficacious Use of Nitinol Stents in the Femoral and Popliteal Arteries.". Journal of Vascular Surgery 38 (6): 1178–1183. doi:10.1016/j.jvs.2003.09.011. 
  2. ^ a b Boden, W. E.; O'Rourke, R. A.; Teo, K. K.; Hartigan, P. M.; Maron, D. J.; Kostuk, W. J.; Knudtson, M.; Dada, M.; Casperson, P.; Harris, C. L.; Chaitman, B. R.; Shaw, L.; Gosselin, G.; Nawaz, S.; Title, L. M.; Gau, G.; Blaustein, A. S.; Booth, D. C.; Bates, E. R.; Spertus, J. A.; Berman, D. S.; Mancini, G. B. J.; Weintraub, W. S.; Courage Trial Research, G. (2007). "Optimal Medical Therapy with or without PCI for Stable Coronary Disease". New England Journal of Medicine 356 (15): 1503–1516. doi:10.1056/NEJMoa070829. PMID 17387127.  edit
  3. ^ Fay Corte, Michelle (26 March 2007). "Stents Fail to Cut Deaths, Heart Attacks in New Study (Update5)". bloomberg.com. Retrieved 6 September 2012. 
  4. ^ Husten, Larry (September 4, 2012). "ESC Trials: The Best And The Worst - Forbes". forbes.com. Retrieved September 6, 2012. 
  5. ^ WINSTEIN, KEITH J. (11 Feb 2011). "Why Health Policies Can Fail to Keep Up With Key Medical Findings". The Wall Street Journal (New York: Dow Jones). ISSN 0099-9660. Retrieved 6 September 2012. 
  6. ^ American College of Cardiology, "Five Things Physicians and Patients Should Question" (PDF), Choosing Wisely: an initiative of the ABIM Foundation (American College of Cardiology), retrieved August 17, 2012 
  7. ^ Patel, M. R.; Dehmer, G. J.; Hirshfeld, J. W.; Smith, P. K.; Spertus, J. A. (2009). "ACCF/SCAI/STS/AATS/AHA/ASNC 2009 Appropriateness Criteria for Coronary Revascularization". Journal of the American College of Cardiology 53 (6): 530–553. doi:10.1016/j.jacc.2008.10.005. PMID 19195618.  edit
  8. ^ "Topic Galleries". Chicago Tribune. 
  9. ^ Ring, Malvin (2001). "How a Dentist's Name Became a Synonym for a Life-saving Device: The Story of Dr. Charles Stent". Journal of the History of Dentistry 49 (2): 77–80. PMID 11484317. Retrieved 27 January 2015. 
  10. ^ Palmaz JC, Sibbitt RR, Reuter SR, Tio FO, Rice WJ. Expandable intraluminal graft: a preliminary study. Work in progress. Radiology. 1985 Jul;156(1):73–77.[PubMed]
  11. ^ Roguin, Ariel (2011). "Historical Perspectives in Cardiology". Circulation: Cardiovascular Interventsions (4): 206–209. doi:10.1161/CIRCINTERVENTIONS.110.960872. Retrieved 6 April 2015. 

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