exposure of the esophagus to caustic material can lead to necrosis , ulceration , fibrosis , and ultimately stricture .
balloon and bougie dilation have similar efficacies for treating these strictures , although stricture recurrence after balloon dilation can occur in up to 30% of these cases .
furthermore , a long - term response can not be guaranteed in cases of non - peptic strictures , and symptomatic recurrence frequently occurs within 1 year after the initial dilation .
thus , caustic esophageal strictures occasionally require a long - term treatment option , and one case report described endoscopic incisional therapy for a patient with a refractory caustic esophageal stricture .
we report a case of an intractable caustic esophageal stricture that was successfully managed with sequential treatment that comprised incision with an insulated - tip knife , balloon dilation , and an oral steroid .
a 58-year - old woman presented with severe swallowing difficulty , because of an esophageal stricture that was caused by accidental exposure to anhydrous acetic acid at infancy .
the patient reported that she had to manually compress the site of the stricture to swallow solid foods , such as meat , and she had grade 2 dysphagia .
she was originally treated using bougie dilation 22 years before the present admission , and we had attempted four balloon dilations during the last 10 years , although the esophageal stricture remained intractable ( figs . 2 , 3 ) .
therefore , we performed incisional therapy parallel to the longitudinal axis of the esophagus using an insulated - tip electrosurgical knife ( itknife nano , kd-612l / u ; olympus , tokyo , japan ) .
the electrical current was generated using an icc200 unit ( erbe elektromedizin gmbh , tubingen , germany ) , which was set to the pure cut current ( endocut mode ; effect 1 , 60 w ) .
this treatment dilated the lumen ( figs . 4 , 5 ) , and her symptoms markedly improved on the next day .
thus , we added two sessions of balloon dilation , and the balloon was inflated to a diameter of 9 mm at 4.5 atm for 30 seconds .
however , her symptoms worsened , and 2 days later , she could not swallow water because of odynophagia .
we performed esophagogastroduodenoscopy and chest computed tomography , which revealed severe wall thickening at the stricture .
therefore , we started oral prednisolone ( 20 mg / day ) , and her symptoms markedly improved by the 2-month follow - up ( grade 1 dysphagia ) .
approximately one - third of patients who experience a caustic esophageal injury subsequently develop an esophageal stricture and the resulting dysphagia can occur 2 weeks after the injury .
the cardinal feature of a caustic stricture is dysphagia because of esophageal narrowing or motility abnormalities , which are closely related to the scarred segment .
more than 80% of caustic strictures can be successfully treated with dilation , and bougie and balloon dilators are equally effective for treating benign lower esophageal strictures .
however , approximately one - third of these cases subsequently develop recurrent dysphagia within 1 year after dilation .
consequently , patients with caustic strictures require a median of five sessions to achieve adequate dilation , compared to three sessions for patients with peptic strictures .
unfortunately , a long - lasting response after dilation can not be guaranteed for non - peptic strictures , and the treatment s effect and re - treatment frequency often depends on the stricture s etiology , length , and severity . we classify esophageal strictures as simple or complex , and the complex strictures are more difficult to treat and tend to be refractory or recurrent , despite dilation therapy .
caustic strictures typically progress to the complex type , and strictures that are long ( > 2 cm ) , angulated , irregular , or severely narrowed tend to be refractory or recurrent , despite dilation therapy .
incisional therapy has been reported as a treatment for anastomotic stricture after gastrointestinal surgery , peptic esophageal stricture , schatzki s ring , esophageal caustic stenosis , esophageal stricture after chemoradiotherapy or endoscopic submucosal dissection , and in combination with another treatment modality .
the success rate of incisional therapy is 80.6% for anastomotic strictures after gastrointestinal surgery , and incisional therapy was also successful in 16 of 20 peptic stricture cases ( 80% ) .
incision and bougie dilation for schatzki s rings , and reported more favorable outcomes for incisional therapy , which provided a longer symptom - free period and a greater reduction in dysphagia scores at 1 month .
described successful incisional therapy for a refractory esophageal caustic stricture in a 44-year - old man , who was free from dysphagia at the 1-year follow - up .
evaluated the usefulness of incisional therapy combined with balloon dilation for cicatricial anastomotic strictures , and reported that five of the six patients exhibited both subjective and objective improvements for > 4 weeks.in the present case , the patient s odynophagia occurred 2 days after the treatment , and we believe that the odynophagia might be related to marked edema and narrowing caused by the electric currents from the incisional therapy , rather than the bougienage after the incision .
there is a report that local steroid injection therapy after endoscopic balloon dilation for benign esophageal stricture can decrease the recurrence of stricture .
furthermore , kim et al .   recently reported that oral steroid therapy after endoscopic submucosal dissection for an esophageal stricture can help prevent relapse after endoscopic balloon dilation .
therefore , in the present case , we used oral steroid therapy to help ameliorate the esophageal inflammatory response and prevent stricture recurrence . in conclusion , we report a rare case of an intractable caustic esophageal stricture that was successfully managed with sequential treatment that comprised incision with an insulated - tip knife , balloon dilation , and an oral steroid
. however , additional studies are needed to confirm the usefulness of this procedure for caustic esophageal strictures .
 bougie or balloon dilation is a good short - term treatment for caustic esophageal strictures , although recurrence after dilation occurs in approximately 30% of these cases . therefore , long - term treatment options are required in some cases , and endoscopic incisional therapy has been used for patients with an anastomotic stricture in the gastrointestinal tract . a 58-year - old woman presented with severe swallowing difficulty because of a caustic esophageal stricture , which was caused by accidental exposure to anhydrous acetic acid at infancy . 
 she had undergone several previous bougie and balloon dilations but the stricture did not improve . 
 we performed sequential treatment comprising incision with an insulated - tip knife , balloon dilation , and an oral steroid , which resulted in the patient s symptoms markedly improving . 
 thus , we report this case of an intractable caustic esophageal stricture , which was successfully treated using combined endoscopic sequential treatment . 
INTRODUCTION
CASE REPORT
DISCUSSION