Esophageal strictures are a problem commonly encountered in gastroenterological practice and can be caused by malignant or benign lesions.Upper endoscopy is the diagnostic procedure of choice for the detection of an esophageal stricture and its underlying cause. Nevertheless, it is mandatory that biopsy samples are taken to confirm whether the stricture is benign or malignant in nature, particularly if the suspicion of malignancy is high. Most treatment options available for the relief or treatment of dysphagia can be performed endoscopically.but can also be caused by
Various modalities are currently available for the relief of dysphagia caused by malignant esophageal stricturesThe options available can be divided into endoscopic and non-endoscopic procedures, and these are equally effective for strictures resulting from either esophageal squamous cell carcinoma or esophageal adenocarcinoma.Worldwide, the most frequently used method to treat dysphagia caused by esophageal or gastric cardia cancer is stent placement. Brachytherapy with or without external beam radiation therapy is another option, which has so far been mainly used in some European countries
Over the past 15 years, SEMS have emerged as the treatment of choice for the palliation of malignant dysphagia. In general, SEMS and SEPS work by splinting open the lumen by their inherent memory that generates a radial expansile force against the obstructing disease. They differ in stent material (steel, nitinol, plas- tic, biodegradable), design, luminal diameter, radial forceexerted, flexibility, and degree of shortening after deploy- ment (braided stents shorten, whereas nonbraided stents do not). Nitinol has now have replaced stainless steel as the dominant material for SEMS given the advantages of shape memory, elasticity, ability to conform better to angulations, and higher radial resistive forces. In addition, nitinol stents are ferromagnetic and thus permit magnetic resonance imaging studies.
—inoperable, poor surgical candidate, contraindication to chemoradiation(primary or secondary mediastinal and lung tumors balloon dilation and not surgically amenable
Fara a rezolvamaiintairiscul de compresie a cailoraeriene
Radiological studies help provide knowledge of a fistula, the proximity of a tumor to airways, to help chose an appropriate length stent and avoid the devastating complications of airway compres- sion. In the latter situation, an endobronchial stent placed prior to treatment would allow for safer deployment of an esophageal stent.24,25 Also, the knowledge of a very high stricture (ie, within 2 cm of the upper esophageal sphincter) on a prior imaging or endoscopic study should probably prompt consideration of a different modality for palliation, given the intense globus sensation and pain that are associated with stents in this location in a significant majority of patients. Radiological stud- ies help provide knowledge of a fistula, the proximity of a tumor to airways, to help chose an appropriate length stent and avoid the devastating complications of airway compres- sion.23 In the latter situation, an endobronchial stent placed prior to treatment would allow for safer deployment of an esophageal stent. Also, the knowledge of a very high stricture (ie, within 2 cm of the upper esophageal sphincter) on a prior imaging or endoscopic study should probably prompt consideration of a different modality for palliation, given the intense globus sensation and pain that are associated with stents in this location in a significant majority of patients. Radiological stud- ies help provide knowledge of a fistula, the proximity of a tumor to airways, to help chose an appropriate length stent and avoid the devastating complications of airway compression. In the latter situation, an endobronchial stent placed prior to treatment would allow for safer deployment of an esophageal stent. Also, the knowledge of a very high stricture (ie, within 2 cm of the upper esophageal sphincter) on a prior imaging or endoscopic study should probably prompt consideration of a different modality for palliation, given the intense globus sensation and pain that are associated with stents in this location in a significant majority of patients.
The initial esophageal SEMS were uncovered in design, but because of rapid tumor or granulation tissue ingrowth, partially covered SEMS were developed that significantly re- duced this problem.From left to right: Ultraflex (Boston Scientific), Wallflex (Boston Scientific), An- tireflux Z-stent (Dua Stent; Cook Inc), and Evolution (Cook, Inc).Comparison between various partially covered SEMS:
From left to right: Alimaxx-ES (Merit Endotek), Wall- flex (Boston Scientific), Evolution (Cook, Inc), Niti-S (Taewoong Medical), and double-type Niti-S (Taewoong Medical).It had antimigration struts that were designed to reduce its migration and a polyurethane coating on the entire stent to reduce tissue injury and hyperplasia. However, some case reports indicated disintegration of the polyurethane, leading to stent fragmentation during removal, which was sometimes traumatic and other times technically difficult.Designed to serve the same purpose as the partially covered SEMS for malignant strictures and to be removable for benign conditions similar to the SEPS, several significant limitations still exist, of which new stricture formation at the ends of the stents and high rates of stent migration are the biggest
Currently, the only available SEPS is the Polyflex stent (Boston Scientific). It is made from a polyester mesh with an inner lining of silicone that extends from the top to the bottom of the stent and covers the ends and tends to reduce the tissue damage and resultant hyperplasia. The top of the stent is flared in an effort to reduce the migration rate, with the middle and bottom of the stent being the same size. Barium is impregnated into the proximal, distal, and mid- points of the stent to facilitate fluoroscopic placement. The stent must be loaded onto a fairly bulky delivery system measuring 12-14 mm prior to placement. This large diam- eter of the delivery systems means that a dilation of the stricture is often required prior to placement.41 The stent can be placed under direct endoscopic visualization or under fluoroscopic guidance alone.Retrieval and/or repositioning can be done with a foreign body grasp- ing forceps or a standard polypectomy snare. The same stent can be reused by reloading it back onto the delivery device in case of a complete migration
Fully and partially covered SEMS that are used to bridge the esophagogastric junction can lead to significant acid reflux and its associated symptoms and complications.Stents with antireflux valves were designed with the intent to reduce this problem. The valve is usually just an extension of the existing lining of the stent (polyurethane or silicone).
The double-type Niti-S stent (Taewoong Medical)A fully covered inner nitinol stent prevents tumor ingrowth, and an outer uncovered nitinol sleeve in the mid-portion of the stent is meant to prevent migration, thus combining the best properties of both stent types.
The largest case series using a biode- gradable stent is from Japan in 13 patients with benign strictures. Spontaneous stent migra- tion occurred in 10 patients within 10-21 days and remained in position in 3 patients. None of the patients had symptoms of restenosis requiring repeat endoscopic intervention
designed to treat refractory cases of esophageal variceal bleeding where transjugular intrahepatic portosys- temic shunt or balloon tamponade would have been the only available alternatives
The Ultraflex and the newer Wallflex stents (Boston Scientific) are both deployed over a stiff guidewire using fluoroscopic and sometimes endoscopic control.The Wallflex stent can also be reconstrained in case there is a need to reposition it prior to full deployment. The Z-stent (Cook, Inc) is also delivered over a stiff guidewire, but it does need to be preloaded into the delivery sheathGiven its nonbraided design, there is no fore- shortening, thereby potentially allowing more accurate ini- tial placement. The stent may be repositioned only proximally by pulling on a suture through the proximal flange of the stent. Given its nonbraided design, there is no fore- shortening, thereby potentially allowing more accurate ini- tial placement. The stent may be repositioned only proximally by pulling on a suture through the proximal flange of the stent.
Once the stent is deployed, it probably is a good idea to invest a few minutes to endoscopically evaluate the final resting place of the proximal end of the stent and ensure its adequate expansion.However, endoscopists should resist the temptation to pass a conventional endoscope through the stent for fear of causing early stent displacement, particu- larly if the stent has not fully expanded. Water-soluble contrast can be injected through the scope to assess the mid and distal portions of the stent if desired during the proce- dure itself. The day after stent placement, we routinely order an esophogram to evaluate its position and function. The pur- pose of this study is to answer a few questions. Does the stent adequately bridge the stricture or close the esoph- agoairway fistula? Is expansion adequate? Does it abut the contralateral wall or is it so angulated to preclude its use? After being satisfied with stent position and function, a dietary consultation and patient education about eating a soft diet with copious fluids are very important. If the stent crosses the esophagogastric junction, aspiration precautions and an antireflux regimen are advised.
(if reflux post stent placement is defined as a complication)
Prolonged chest pain caused by stent expansion is more common with larger and more flared stents.case reports of erosion of the stents into the airway or adjacent vascular structures, which can occur early or late
Fully covered SEMS and SEPS have a higher incidence migration compared with partially covered SEMSUncovered stents have the best antimi- gration properties, but lead to the quickest occlusion with tumor/tissue ingrowth, which can cause complete obstruc- tion, sometimes within weeks. At this time, the main ad- vantage of plastic stents over fully covered metal stents is the tendency to cause a lesser hyperplastic tissue response than metal. Larger stents do reduce the risk of migration, but come with the price of more discomfort and increased risk of pressure necrosis
Late recurrent dysphagia can be caused by tumor overgrowth or ingrowth, granulation tis- sue, or epithelial hyperplasia, which can be treated with debulking therapy (laser, argon plasma coagulation), bal- loon dilation, or restenting.The need for repeat procedures after esophageal stenting, according to the British Registry of Esophageal stenting, approaches 60% at 6 months, with stent migration and reocclusion being the most common reason for reintervention.
The mainstay of treatment for benign esophageal strictures is dilation. Although dilation usually results in symptomatic relief, recurrent strictures do occur. In order to predict which types of stric- tures are most likely to recur, it is important to differentiate between esophageal strictures that are simple and those that are more complex
Of these, the Savary-Gilliard® and TTS balloon dilators are currently by far the most frequently used. The main difference between these two dilators is their mechanism of action. A Savary-Gilliard® dilator exerts a radial force as it is passed down, but some of its dilating force is transmitted longitudinally because of its shearing effects. By contrast, longitudinal forces are not transmitted with balloon-type dilators.Nonetheless, no clear advantage has been demonstrated for either one of these two dilator typesSavary-Gilliard® dilators are more cost-effective as they can be re- used, whereas TTS balloon dilators are intended for single use only.
Simple stricture- 1–3 dilations are required to relieve symptoms, with an additional 25–35% of patients requiring repeat dilationsComplex stricture- at least three dilation sessions to relieve symptoms recur within a time interval of 2–4 weeks, or require ongoing (more than 7–10) dilation sessions stent placement and incisional therapy
The main complications associated with esophageal dilation include perforation, hemor- rhage and bacteremia. To minimize the risk of perforation, the "rule of threes”:
Esofag - Mamaia 2011
Complicatiile dilatarii si protezarii stenozelor esofagiene
Stenoza esofagiana Benigna: injurie caustica, inel Schatzki, membrane esofagiene, post iradiere, stenoze anastomotice Maligna Cancer esofagian primar Tumori extraesofagiene care comprima esofagul. Disfagia este simptomul comun, indiferent de cauza stenozei (maligna sau benigna).
SEMS: Aliaj nichel si titaniu (nitinol) Neacoperite, acoperite total, partial acoperite Impletite, neimpletite – scurtare 25-30% de la ambele capete dupa insertie SEPS Biodegradabile Stenturi active farmacologic (chimioterapice)
Indicatii pentru montarea SEMS si SEPS Stenoze esofagiene maligne nerezecabile Recidiva maligna postchirurgicala Compresie extrinsica esofagiana Fistula traheoesofagiana –maligna sau benigna Perforatie esofagiana—iatrogena sau spontana Stenoze benigne refractare Acalazia refractara—ELLA-BD stent Varice esofagiene cu sangerare (alternativa /contraindicatie TIPS Temporizare chirurgie
Contraindicatii SEMS si SEPS Stenoza maligna rezecabila Pacient terminal cu speranta de viata limitata Stenoza < 2 cm sfincterul esofagian superior Risc de compresie a cailor aeriene Chimioterapie recenta (< 3-6 saptamani) Obstructie gastroduodenala si/sau intestin subtire netratata Sepsa Coagulopatie
SEMS partial acoperite Prezinta capete de metal proximal si distal care permit ancorarea la nivelul peretelui esofagian Nu exista diferente: Succes terapeutic Imbunatatirea disfagiei Status performanta Supravietuire Complicatii Disfagia recurenta Migrarea stentului a fost asociata cu diametrul redus/nu cu tipul de stentVerschuur et al., Am J Gastroenterol 2008
SEMS acoperite total Stent din nitinol acoperit in intregime cu poliuretan si silicon Dispozitive de extragere atasate la capetele proximal/distal Dezintegrarea poliuretanului Fragmentarea stentului in timpul extragerii Limitari: Formare de noi stenoze la capete Procent ridicat de migrare
SEPS acoperite total Proteza Polyflex(Boston Scientific) retea poliester tapetata intern cu silicon insertie sub control fluoroscopic (markeri bariu) Dilatarea stenozei anterior insertiei sistem de insertie 12-14 mm 1-2 cm deasupra si sub stenoza extragere si/sau repozitionare/refolosire Stenoze esofagiene maligne: procent mai ridicat de complicatii si migrare decat SEMS Stenoze esofagiene benigne: migrare procent crescut de complicatii rata scazuta de succes pe termen lung
Stent antireflux jonctiunea gastroesofagiana nu exista beneficii semnificative comparativ cu protezele clasice partial acoperite (Ultraflex) cand se adauga terapia cu IPP. Sabharwal T, et al: J Gastroenterol Hepatol 2008
SEMS duble Niti-S stent (Taewoong Medical) Design special stent-in-stent: reduce migrarea si invazia tumorala Procentul cel mai scazut de migrare in stenozele maligne: 8% Verschuur EM, et al. Am J Gastroenterol 2008
Stenturi biodegradabile Aliaj magneziu, polimeri acid poliglicolic, polidiaxona markeri radio-opaci la ambele capete capetele proximal si distal sunt evazate pentru a reduce migrarea Integritatea si forta radiala se mentin timp de 6-8 saptamani Dezintegrarea stentului apare dupa 11-12 saptamani pH scazut (reflux acid) poate produce dezintegrare mai rapida Dificultati inerente cu preincarcarea stentului si radioopacitatea diminuata Ella-BD stent (ELLA-CS)
SEMS acoperite total pentru tratamentul varicelor esofagiene refractare Nitinol / retea cu ochiuri variabile permite miscarile de peristaltica esofagiana capete atraumatice Markeri radio-opaci la ambele capete si in portiunea medie/ dispozitiv de extragere la ambele capete Se recomanda extragerea la 7 zileWright G, et al: Gastrointest Endosc 2010 SX-ELLA-Danis stent (ELLA-CS)
Stentarea esofagului - tehnica 2 cm deasupra si sub tumora Marcare: marcheri externi (agrafa) marcheri interni (clip/substanta contrast) viziune directa (eliberarea proximala) Dilata anterior – sistem de insertie proteza Marginea tumorala proximala > 2 cm distal de SES Control fluoroscopic si endoscopic
Ingrijire post protezare Alimentatie semisolida Scaderea apetitului post protezare Proteza impiedica peristaltica fiziologica a esofagului Evaluare endoscopica a capatului proximal al protezei – expasiunea eficienta Nu se recomanda pasarea endoscopului prin proteza deplasare precoce a stentului, mai ales daca acesta nu este expandat complet Protezarea jonctiunii GE regim antireflux, preventia aspiratiei Esofagograma a 2-a zi post protezare eficienta inchiderii fistulei eso-traheale / permeabilizare stenoza verificare pozitie proteza
Dilatare esofag sonde de cauciuc cu mercur Maloney [Medovations, WI] dilatatoare rigide cu fir ghid Savary-Gilliard [Cook Medical] dilatatoare cu balon prin endoscop (TT sau cu fir ghid [Boston Scientific]
Dilatarea esofagiana Acalazie Depinde de lungime si diametru Stenoze stranse sau complexe < 10 mm in diametru > 2 cm in lungime Bujii cu fir ghid sau baloane sub control fluoroscopic si endoscopic Stenoze simple - bujii Maloney Dilatare progresiva (saptamani-luni) cu cresterea graduala a diametrului bujiilor Remisia disfagiei dupa dilatare la 40 - 54 French Nu necesita terapie de mentinere Studiu cu gastrografin post dilatare /Ba pasaj Exclude perforatia esofagiana
Complicatii Dilatare esofagiana perforatie , sangerare , bacteriemie - 0 ) Stenoze maligne sau post-iradiere – risc crescut perforatie Regula de trei: Maxim 3 dilatari succesive /sesiune Diametru esofagian > 15 mm din pacientii dilatati la mm nu prezinta recurenta la 24 luni
Stenoze esofagiene benigne Rezultate dezamagitoare? Durata si severitatea raspunsului inflamator: Temporar in stenozele peptice Cronic in stenoze post-anastomotice, post-iradiere si caustice Tip stent: SEMS partial acoperite se asociaza cu roliferãri de tesut conjunctiv reactiv SEPS procent ridicat de migrare Dua KS, et al. Am J Gastroenterol 2008
Concluzii Acoperit e mai bine (JGE – migrare) Nitinol (curbe) vs otel (forta radiala mai mare) Diametrul mai mare este mai eficient Protezarea JGE – doza dubla IPP, prokinetice
Concluzii UltraflexTM, Wallflex si Niti-S stents – paliatia disfagiei maligne Z-stents si Polyflex® - procent ridicat de complicatii Nu exista diferente in ceea ce priveste eficienta bujiilor Savary-Gilliard® si dilatatoarelor cu balon in tratamentul stenozelor esofagiene benigne Protezele sunt montate la pacientii cu stenoze benigne complexe refractare la terapia de dilatare