Study Of Clnical Application Of The Covered Stent In The Treatment Of Esophageal Diseases

Objective:To evaluate the clinical efficacy and complications of the covered esophageal stents in the treatment of esophageal stricture resulted from benign or malignant diseases and esophageal rupture,retrospectively. Materials:Under fluoroscopic guidance,369 stents were placed in 326 patients (202 men, 124 women,age ranged from 5 to 94 years ,mean 62.6 years),314 patients with dysphagia due to benign (including 41 cases of stricture at the site of anastomosis, 16 cases with caustic erosion,3 cases of systemic disease )or malignant (including 254 cases of carcinoma of esophagus or cardia)obstruction,and 12 patients with esophageal rupture were treated with covered stents.The main symptoms included progressive dysphagia or aphagia,chest pain,choking,emaciation and bleeding.All patients came with their X—ray,CT or MRI films. 108 patients had undergone surgical resection of esophagus ,66 patients were diagnosed with endoscopy,5 patients were punctured percutanuously .All those patients who were diagnosed as benign lesions had unequivocal history or had endoscopic corroboration.An additional stent was necessary to be placed in 37 patients(8 benign cases and 29 malignant cases),the third one was placed in 3 patients (all were benign cases).In our study,two kinds of stents were used :one was nitinol stent(NTS),the other was stainless steel "Z"stent(SSZS).NTS was made of 0.2mm nitinol wire,woven in a crisscross fashion to form a cylindrical mesh,which had a shape memory that allowed the stent to assume the proper configuration once released from its constraining delivery assembly. 112 NTS were placed in our study.The stent was 18—20mm in diameter and 60—140mm in length.One or both ends ofthe stent about 10mm were flared and bared to prevent the stent's migration,while the body of the stent was covered with silicone membrance to prevent ingrowth.The other kind of stent was made of stainless steel wire,woven in a zigzag fashion,with a soft connection between two "Z"bodies and one or two pairs of inversus thorns to prevent stents migration.This kind of stent was 13—19mm in diameter and 55—190mmin length. 257 SSZS were placed in our study.Methods of stentplacement and removal:All of the stent insertion were performedunder fluoroscopic guidance.An aerosol spray for topical anesthesia(spray and gel lidocaine) was applied to the mouth and pharynx.Drugs such as 10—20mg 654—2 or 0.5mg atropine was administered routinely before the procedure.Picked out the patients'movable false—tooth.With the patient in the right lateral or supine position and in full extension of the neck,a 8F big lumen catheter with a super smooth guidewire was passed into the esophagus perorally.Let the patient swallow when the guidewire passed through the pharynx.The catheter was passed over the guidewire as far as the distal portion of the stricture. Withdrew the guidewire and injected some water—soluble contrast while pulling the catheter upward to show the range of the lesion to verify the diagnosis made previously.Then the location of the lesion in the esophagus was marked on the patients' skin under fluoroscopic guidance both in supine and lateral position.Let the catheter with super smooth guidewire go through the lesion,exchanged the super smooth guidewire with a super stiff steel wire until its distal spring end was kept in stomach to be used.Savry—Gilliard dilator,whose distant part was lubricated with paraffin oil ,was passed over the kept guidewire into the esophagus and advanced until the dilator reached the spring part of the wire to dilate the stricture(if necessary) from 5mm to 9mm,one by one.In this procedure,if the resistance from the tight stricture was magnificent,dilated it with the next thicker dilator. Without massive bleeding,the stent assemblywas introduced into the esophagus until the distal tip of the stent reached about 2cm beyond the stricture marked before. Locating the stent carefully,released the stent under fluoroscopic guidance on end.Withdrew the stent assembly together with the guidewire.If patients had no obvious complications,let them have fluid food in 3 days,soft food 3—6 days and ordinary food 1 week later.For those patients with split esophagus,kept a good drainage and gave sufficient antiphlogistic and nutritional supplement.Stent removal:Inserted an 8F big lumen cathether with a super smooth guidewire as above—mentioned in stent placement.The catheter should be confirmed with contrast in the lumen of the stent which would be removed .A steel wire with a hook on its distal end was introduced into the lumen of catheter.When the hook appeared beyond the catheter,withdrew the catheter together with the hook until the kook neared the upper inner edge of the stent.Tried to hook the removal string.When the stent shrinked,withdrew the hook while pushing the catheter to tighten up the string.Pulled the hook and the catheter out of the mouth fast.Then the stentwas removed successfully.ResultS:369 stents(112 NTS,254 SSZS) were placed in 326patients.343 stents (92.9%)were placed one time ,23 stents(6.2%) at the second time and 3 stents(0.9%) at the third time.lt was satisfactory of immediate location in 337 stents(91.3%) and 32 stents (8.7%) after adjustment.Patients condition improved in a short time.X2 test showed that there was significant difference (P<0.001) of swallow after placement of stent.Esophagus—trachea(or bronchus) fistula or esophagus rupture or fistula at the site of anastomosis in 74 and 76 cases diappeared 24 and 72 hours after stent placement ,accounting for 91.3% and 93.8%,respectively.In our group,complications included chest pain(118 cases),restenosis(61 cases),stent migration(83 cases),esophagus reflux(67 cases),bleeding(52 cases,one patient died of massive bleeding 30 hours later),stent blockage(46 cases) and eructation(12 cases).X2 test showed thatstent in CE resulted in much more severe pain(P<0.01) and stent migration(P<0.05) than in other regions.NTS resulted in more restenosis than SSZS(PO.Ol) while SSZS had higher rate of stent migration than NTS(P<0.01).There were no significant difference (P>0.05) both about bleeding resulted from different stents in different regions of esophagus and esophagus reflux resulted from two kinds of non—antiruflux.Stents Adjustment (6cases),an additional stent (25cases) and only dialation(30cases) palliated 61 restenosis patients effectively.Conclusion:l.Esophageal stent placement was a safe,simple and relatively cheap and dependable management with microtrauma for those who had lost the chance of surgical resection or refused to undergo operation.2.Clinical application of retrieavable stent set up a new way to treat benign esophagus stricture or rupture.Of course,patients needed a series of treatment such as endoscopy,medical supporting,surgical drainage,life rescue and so on.3.It was necessary to have an ample dilation in advance if the stent was placed in CE.SSZS was intensely recommended when the scope of the lesion was higher than T2,while antireflux stent should be used at the site of anastomosis or when striding cardiaAFor malignant lesions,placement of stent was only a pallative measure because the stent had no use in treating tumor. When permitted,these patients should undergo one or more other treatment such as chemotherapy,radiation or immunization therapy.5.Stent removal was easy to do,but it would be impossible,despite the aid of endoscopy,to remove the stent when the removal string was covered deeply by tumor or other tissue .6.During and after the placement of stent ,there existed some unavoidable complications such as chest pain,stent migration,restenosis,bleeding,stent blockage,esophagus reflux and eructation.If the stricture was too stiff and narrow to pass the guidewire through,we can do nothing about the procedure.7.Long term observation of the cytological and histological...