endoscopic submucosal dissection ( esd ) has been performed widely and safely as an established treatment for superficial esophageal neoplasms.1 to date , the indication for esd has been gradually extended to larger lesions . however , as large superficial esophageal neoplasms became candidates for esd , a substantial number of post - esd strictures have been reported.2 in particular , esophageal stricture mostly occurs after near - circumferential or whole - circumferential esd at a rate of 88% to 100%.3 post - esd stricture decreases the patients ' quality of life and usually requires multiple sessions of risky endoscopic balloon dilatation ( ebd).4 recently , the efficacy of prophylactic oral prednisolone in preventing post - esd stricture was reported.5 according to the report , oral prednisolone may be effective in reducing the need for ebd . however , the cumulative dose of prednisolone was high and associated with serious adverse events .
a previous study reported that intralesional injection of triamcinolone reduced the incidence of stricture and the number of required ebd sessions.6 however , there is little experience in intralesional steroid injection for near- or whole - circumferential esd ulcerations . furthermore , there is no established method of injection to date .
we report a patient with superficial esophageal squamous cell carcinoma who underwent complete near - circumferential esd and then received a single session of intralesional steroid injection immediately after esd .
dysphagia and the need for ebd have not developed after a follow - up period of 6 months .
all the laboratory findings were within normal limits . computed tomography and positron emission tomography revealed no distant metastasis .
an initial upper endoscopy showed a lugol - voiding lesion involving more than three - quarters of the circumference of the lower esophagus , extending 39 to 43 cm from the incisors ( fig .
histopathological findings from another hospital revealed high - grade squamous cell dysplasia , but squamous cell carcinoma could not be excluded .
, we needed to obtain clearer views and to control the scope in detail throughout the procedure ; therefore , this patient underwent esd with tracheal intubation and general anesthesia in an operating room .
the esd procedure was performed using a single - channel upper endoscope ( gif - h260z ; olympus , tokyo , japan ) with a transparent cap .
circumferential markings were made using a hook knife ( kd-620lr ; olympus ) just outside the lesion , on soft coagulation mode of a high - frequency generator for electrosurgery with an automatically controlled system for cutting and coagulation ( erbe , tbingen , germany ) .
a total amount of 80 ml normal saline solution mixed with epinephrine was injected into the submucosal layer to lift the mucosa including the tumor .
after the lesion was lifted , mucosal incision and dissection was made with a hook knife and an it knife ( kd-611l ; olympus ) ( fig .
just after dissection and hemostasis , a single - session endoscopic triamcinolone injection was administered ( fig .
triamcinolone acetonide ( triam , 40 mg / ml ; shinpoong co. , seoul , korea ) was diluted with saline to make a 20 mg / ml solution .
a total of 80 mg ( 4 ml ) triamcinolone was injected into the deep submucosa and the superficial proper muscle layer of the ulcer base at eight sites , with a 0.5 ml dose at each site .
the depth of needling was as shallow as producing a small amount of spillage into the esophageal lumen side during injection to avoid possible abscess formation .
three neoplastic lesions ( 3817 , 117 , and 73 mm ) were found in the specimen ( fig .
the histopathologic diagnosis was well - differentiated intramucosal invasive carcinoma confined to the lamina propria without lymphovascular invasion .
serial esophagography was performed 2 and 4 weeks later to assess the post - esd stricture .
mild irregular segmental narrowing was seen in the lower esophagus , but no definite passage disturbance was observed ( fig .
follow - up upper endoscopy was performed after 4 months , which revealed only a post - esd scar ( fig .
the patient did not complain of dysphagia and showed a good outcome for 6 months after esd .
post - esd stricture is a major complication especially in esophageal esd . in a previous report
, multivariate analysis revealed that a circumferential extension of more than three - quarters and a histological depth to m2 are reliable independent predictors for post - esd stricture.3 as larger superficial esophageal neoplasms became candidates for esd , substantial post - esd strictures have been reported .
indeed , the rate of esophageal strictures after esd for near - circumferential or whole - circumferential lesions has been reported to be surprisingly as high as 88% to 100%.7 however , there are no guidelines for the treatment of post - esd esophageal stricture , and most of the previous studies have been performed retrospectively . until now , multiple sessions of ebd is the preferred treatment of esophageal stricture regardless of etiology;8 however , this can increase the risk of perforation , massive bleeding , and bacteremia.4 for this reason , the development of strategies to prevent post - esd stricture is important .
periodic balloon dilations and temporary stenting were used to prevent post - esd stricture in some institutes .
fujishiro et al.9 reported that repetitive , periodic ebd was effective in controlling and preventing post - esd stricture .
however , isomoto et al.10 reported that a scheduled preventive ebd immediately after esd was needed in a median of 30 times for circumferential cases .
several studies suggested that severe inflammation , fibrosis , and scarring in the exposed submucosa after esd might play an important role in the formation of stricture . according to that theory ,
post - esd stricture might be prevented by controlling such inflammation.11 steroid can inhibit fibrosis by preventing the migration and activation of inflammatory cells and fibroblasts.12 a few studies reported on the effectiveness of prophylactic oral prednisolone for the prevention of post - esd stricture . as a result , the rate of stricture was decreased together with the number of needed ebd procedures.5,10 however , the cumulative dose of prednisolone administered was approximately 1,000 mg .
the potential risks of such a high dose , such as immune suppression , psychiatric disturbance , peptic ulceration , and optical damages , were a cause for concern .
hashimoto et al.6 reported that endoscopic intralesional injection of triamcinolone was safe and effective for the prevention of esophageal stricture after esd for superficial esophageal carcinoma .
triamcinolone was injected into post - esd ulceration 3 , 7 , and 10 days after esd .
however , it needed three additional endoscopic procedures , causing inconvenience and additional costs to the patients .
moreover , the enrolled patients had a semicircumferential mucosal defect with a relatively low risk of post - esd stricture . in a controlled prospective study ,
hanaoka et al.13 showed promising results with a single session of intralesional steroid injection immediately after esd for preventing post - esd stricture .
compared with the historical control group , the study group had a significantly lower stricture rate ( 10% vs. 66% ) .
we injected triamcinolone immediately after esd in the exposed submucosa of the post - esd ulceration in the same manner .
however , the other authors diluted triamcinolone solution up to 5 mg / ml . because the total amount of the injected triamcinolone was roughly similar to that in our case ( 100 mg vs. 80 mg ) , the injected volume and the number of needlings were larger than those in our case ( 10 ml vs. 4 ml , 20 to 40 punctures vs. 8 punctures ) .
therefore , our method of steroid injection was much simpler than that in any previous study . furthermore , our patient had a near - circumferential mucosal defect , whereas other studies excluded patients with near - circumferential defects because of the extremely high risk of esophageal stricture .
because injected triamcinolone usually remains locally active for 3 to 4 weeks , we did not repeat the injection.14 in this case , no adverse events related to triamcinolone injection occurred .
however , a previous animal study reported that direct injection of triamcinolone into the exposed esophageal submucosal tissue of four pigs resulted in the complication of esophageal abscess.15 in addition , potential risks of perforation , mediastinitis , and pleural effusion may be associated with local injection therapy .
to prevent excessively deep mural injection , we performed the triamcinolone injection very carefully while checking for minor spillage from the injection site .
there are no standard guidelines to prevent stricture in a patient with near - circumferential or circumferential mucosal defect after esd .
many methods to prevent post - esd stricture , such as repetitive ebd , temporary stent insertion , and oral steroid and intralesional steroid injection , have been used by different institutes individually . because there are no randomized controlled studies comparing those methods , any method can not be widely accepted . in this case
, we showed that a single session of intralesional steroid injection into a post - esd ulcer was an effective and convenient method to prevent post - esd stricture .
this method of steroid injection was also simpler and safer than those reported in other previous studies .
however , the true benefit and the risks of injection have not been validated yet .
 stricture frequently occurs after endoscopic submucosal dissection ( esd ) for superficial esophageal carcinoma with near- or whole - circumferential mucosal defects , and post - esd stricture is difficult to treat and usually requires multiple sessions of endoscopic balloon dilatation . 
 intralesional steroid injection has previously been used to prevent stricture ; however , there have been few experiences with this method after near- or whole - circumferential esd . 
 we present a case of a single session of intralesional steroid injection performed immediately after near - circumferential esd to prevent post - esd stricture . 
 after a follow - up period of 6 months , the patient showed good outcome without dysphagia . 
INTRODUCTION
CASE REPORT
DISCUSSION