Enteral stents

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stents used in gastroenterology

Transcript of Enteral stents

  • 1. DR VARUN K

2. History Introduction Types of Stents Indications for stenting Procedure Side effects Esophageal stents Gastroduodenal stents Colonic stents 3. Invented in 1856 by the English dentist Charles Stent . Jan F. Esser, a Dutch plastic surgeon who in 1916 used the word stent to describe a dental impression compound to craft a form for facial reconstruction 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 4. The evolution of enteral stents has gone through stages over the last 125 years. Sir Charters Symonds was the first to successfully place an esophageal prosthesis across a malignant stricture. There were many modifications of rigid esophageal stents in which various materials (wood, metal, plastic, latex) and designs were used 5. Celestin designed a new prosthesis and, following its commercial availability in the 1970, the stent revolution accelerated. The rigid prosthesis (plastic and latex) was extensively used from the 1970s to the 1990s, but the complication rates and mortality associated with insertion-related perforations remained significant. In the early 1990s, self-expandable metal stents (SEMS) were developed for esophageal use a decade after their introduction into the vascular and biliary tree 6. Stents are devices used to maintain or restore the lumen of hollow organs, vessels, and ducts. There are three types of expandable stents: metal, plastic, and biodegradable 7. There are three varieties of metal stents: uncovered, partially covered, and fully covered. The advantage of covered stents is that they resist tumor ingrowth, but they have a higher migration rate, especially when fully covered but advantage of potentially being removable. 8. Partially covered stents are uncovered at their ends, which allows the stent to embed in the tissue and helps to prevent migration. Uncovered stents are less likely to migrate, but are subject to tumor ingrowth and resultant obstruction. 9. SEMSs consist of woven, knitted, or laser-cut metal mesh cylinders that exert self-expansive forces until they reach their maximum fixed diameter. SEMSs are composed of stainless steel, alloys such as elgiloy and nitinol, or a combination of nitinol and silicone. 10. Elgiloy, an alloy composed primarily of cobalt, nickel, and chromium, is corrosion resistant and capable of generating high radial forces. Nitinol, an alloy of nickel and titanium, yields increased flexibility that is helpful for stenting sharply angulated regions at the cost of lesser radial force. 11. To prevent tumor ingrowth, the interstices between the metal mesh of esophageal SEMSs may be wholly or partially covered by a plastic membrane or silicone. For tumors located near the GE junction (Esophageal Z-stent with Dua Anti-reflux valve; Wilson-Cook Medical, Winston-Salem, NC) uses an extended polyurethane membrane 8 cm beyond the metal portion of the stent to prevent gastroesophageal reflux 12. An SEPS (Polyflex; Boston Scientific, Natick, Mass) has been developed for esophageal strictures. This stent has a woven polyester skeleton and is completely covered with a silicone membrane. 13. The silicone prevents tissue in growth through the mesh. Polyester braids on the external surface anchor the stent to the mucosa to limit migration. 14. Esophageal Degradable BD (Ella-CS, Czech Republic) is made from woven surgical suture material, polydioxanone. It is uncovered and does not have an anti-reflux valve. The stent fully degrades in approximately three months 15. PROXIMAL RELEASE DISTAL RELEASE COAXIAL RELEASE SUTURE RELEASE 16. Dysphagia from esophageal malignancy. benign esophageal strictures (peptic, radiation induced, anastomotic, and caustic). Postoperative leaks. iatrogenic perforations. 17. external compression from extraesophageal tumors. tracheoesophageal fistulas. Achlasia cardia. Bleeding varices. 18. Stents vary in length from 6 to 19.5 cm and in shaft diameter from 10 to 23 mm. Wallflex (Boston Scientific, Inc, Natick, MA) partially and fully covered nitinol stents without an anti-reflux valve Esophageal Z stent (Cook Endoscopy, Winston-Salem, NC) partially covered stainless steel stent, available only with the Dua anti-reflux variant 19. Evolution (Cook Endoscopy) partially covered and fully covered nitinol stents without an anti-reflux valve Ultraflex stent (Boston Scientific, Inc) partially covered and uncovered nitinol stents without an anti-reflux valve Alimaxx-E stent (Merit Endotex) fully covered nitinol stent with and without an anti-reflux valve. Niti-S (Taewoong Medical Co, Korea) fully covered nitinol stent without an anti-reflux valve; this stent comes in two versions, the covered Niti-S and the double-layered Niti-S that has an additional layer of nitino 20. ELLA-CS FerX-Ella Esophageal Stent -Stainless steel (fully covered with polyethylene) SX-Ella Esophageal Stent- Nitinol (fully covered with silicone) 21. 0Able to consume a normal diet 1Dysphagia with certain solid foods 2Able to swallow semi-solid soft foods 3Able to swallow liquids only 4Unable to swallow saliva (complete dysphagia) 22. Assessment of the length of the stricture and degree of obstruction is the first step If the stricture is too tight to advance a standard gastroscope, an ultrathin endoscope may be used. To guide accurate stent deployment, the proximal and distal ends of the stricture need to be marked appropriately 23. During stent selection, it is important to choose a stent length that is 4 cm longer than the stricture being stented. This allows for 2 cm of stent on either end of the stricture to decrease the risk of migration. 24. Foreshortening is the property of the stent by which, on fluoroscopy, the stent constrained in its catheter will appear longer than the unconstrained deployed stent length. stenting a stricture in the cervical esophagus ensure at least a 2-cm distance between the proximal end of the stent and the upper esophageal sphincter 25. misplacement (0.3 percent), failed expansion (3.9 percent), failed deployment (0.8 percent), and migration (0.3 percent) gastroesophageal reflux disease (3.7 percent), recurrent dysphagia (8.2 percent), tracheoesophageal fistula (2.8 percent), 26. bleeding (3.9 percent), perforation (0.8 percent), and death within 30 days that was not related to immediate stent placement (7.4 percent) Esophageal self-expandable metallic stents--indications, practice, techniques, and complications: results of a national survey.Ramirez FC, Dennert B, Zierer ST, Sanowski RA Gastrointest Endosc. 1997;45(5):360 27. Benign esophageal strictures are classified as simple or complex. Simple strictures are straight and short (< 1 cm) and can be easily passed with a normal diameter (8 to 10 mm) endoscope. Complex strictures are often longer (> 2 cm), angulated, and sufficiently narrow that passing a normal diameter endoscope is difficult. 28. Complex strictures are due to radiation, photodynamic therapy, caustic ingestions, and surgical anastomoses. Refractory strictures are defined as those that cannot be dilated to 14 mm over 5 sessions at 2-week intervals. Recurrent strictures are defined as those that do not maintain satisfactory luminal diameter for 4 weeks after dilation to at least 14 mm. Kochman M, McClave S, Boyce H. The refractory and recurrent esophageal stricture a definition. . 2005;62(3):474-475 29. SEPS should optimally be left in place for at least six weeks to allow for remodeling of the scar tissue. A longer period may be required in patients with post- radiation or anastomotic strictures, which have a greater tendency to recur. 30. Systematic review: the role of self-expanding plastic stents for benign oesophageal strictures.Repici A, Hassan C, Sharma P, Conio M, Siersema P Aliment Pharmacol Ther. 2010;31(12):1268. Results:Data of 10 studies with 130 treated patients were included. SEPS insertion was technically successful in 128 of 130 patients (98%).. 31. A comparison of temporary self-expanding plastic and biodegradable stents for refractory benign esophageal strictures. van Boeckel PG, Vleggaar FP, Siersema P Clin Gastroenterol Hepatol. 2011;9(8):653 Placement of SEPSs or biodegradable stents provides long-term relief of dysphagia in 30% and 33%, respectively, of patients with RBES. Biodegradable stents require fewer procedures than SEPSs, offering an advantage. Although stent placement is a viable strategy in patients with RBES, the ideal strategy still needs to be defined 32. The use of expandable uncovered metal stents for benign esophageal strictures is not recommended. 33. Four studies examined the use of a FCSEMS without flared flanges (Alimaxx-ES esophageal stent, Merit Medical Systems Inc) in benign esophageal disease . Treatment success varied from 21 to 100 percent, depending upon the indication for stent placement (fistula/leak or perforation and strictures 34. Three additional types of newly developed FCSEMSs with the presence of flared flanges (ie, "dog bone" design) have been used with success: Wallflex esophageal stent (Boston Scientific Inc, Natick, MA) Bonastent esophageal stent (EndoChoice Inc, Alpharetta, GA) Evolution esophageal stent (Cook Medical Inc, Winston-Salem, NC) 35. A comparison of the temporary placement of 3 different self- expanding stents for the treatment of refractorybenign esophageal strictures: a prospective multicentre study. Temporary placement of a biodegradable stent or of a FCSEMS in patients with RBES may lead to long-term relief of dysphagia in 30 and 40% of patients, respectively. The use of SEPSs seems least preferable, as they are associated with frequent stent migration, more reinterventions