2017-18 HSC Section 3 Green Book

Gastroenterology and nutrition

wire under radiographic control as the primary approach to treating strictures [6 & ,7,13,27]. The advantage of balloon dilatation is that it applies radial pressure to the stricture instead of shearing longitudinal forces associated with the other tech- niques [12 & ,13]. The radial pressure is thought to minimize the risk for esophageal perforation. Balloon dilatation has been shown to be as effective as other bougienage techniques with the lower risk of perfor- ations [13,25,27]. Typically, it has been recommended that esoph- ageal dilatation be performed starting 4 6 weeks after the initial ingestion to allow for healing of the mucosa [26]. However, recent studies indicate that esophageal dilatation can be safely performed as early as 5–15 days after ingestion without the increased risk of complications [5,6 & ,27,28]. Further- more, these studies, based on small numbers of patients, propose that early dilatation may improve the outcome of esophageal injury and decrease the risk for long-term stricture formation. Larger, pro- spective, multicenter controlled studies are needed to confirm this hypothesis. Strictures may require serial dilations over several months or years. The optimal frequency and total number of dilatations have not been prospectively studied. Observational data suggest that they should be initially performed every 1 3 weeks until oral feedings are tolerated. Thereafter, the interval of dilatation sessions can be regulated based on the reoccurrence of symptoms [12 & ,13,27,28]. Factors that indicate a poor prognosis in achieving a success- ful outcome are delay in initial onset of presentation, grade 3 injury, persistent esophageal ulceration, densely fibrotic stricture that cracks with dilatation, stricture longer than 5 cm, and an inability to estab- lish lumen patency despite repeated dilatations over 1 2 years [12 & ,27]. ADJUNCTIVE TREATMENT Adjunctive treatments have been used to minimize the risk of stricture reoccurrence following dilata- tion, but there have been no large, prospective, controlled trials to determine the efficacy for any of these therapies. Triamcinolone acetate injection into the stricture site following dilatation seems to have a preventive effect on collagen synthesis, fib- rosis, and chronic scarring [25]. Larger studies are needed to confirm this approach. Observational evidence and a small double-blinded, randomized, placebo-controlled trial suggest topical application of mitomycin C solution, an inhibitor of fibroblast proliferation, to the fibrotic area immediately after dilation may slow down the regeneration of scar tissue [29,30,31 & ]. Novel techniques for the

application of mitomycin C have been developed to minimize the risk of side-effects [29]. Prospective long-term studies are needed to determine the appropriate dosage, frequency of administration, and total number of applications [32]. Some investigators have advocated the place- ment of self-expanding esophageal stents for severe burns [33–37,38 & ]. During the past 30 years, various types of stents have been used (silicone, polytetra- fluoroethylene, metal expanding, and biodegrad- able). They typically will remain in place for at least 3 6 weeks to allow for epithelialization to form [12 & ,20]. Biodegradable stents have the advantage of not requiring endoscopic removal. Stents have been associated with many complications including gas- tro-esophageal reflux, chest pain, erosions of the esophagus, displacement, tissue hyperplasia at each end of the stent, and complications associated with removal. Only small case series have been reported, and larger studies are needed to provide a clearer picture of the benefits and risks involved with the use of stents in caustic esophageal burns. Strictures that are refractory to management may require partial esophageal resection with reversed gastric tube esophagoplasty, colonic inter- position, jejunal interposition, colonic patch esoph- agoplasty, or gastric advancement [12 & ]. All of these procedures have been available for several years. Which approach is used is dependent on local experience and weighing the morbidity and mortality involved against continuation of non- surgical intervention [27]. Because there is no ideal graft that will substitute for the native esophagus, better medical therapies are needed to avoid surgical intervention. Pyloric stenosis and gastric outlet obstruction can also occur after caustic ingestion and can be treated with either balloon dilatation [39] or surgical intervention [24]. RISK OF CANCER Caustic ingestion with stricture formation is associ- ated with an increased risk of esophageal, but not gastric carcinoma. The risk of developing either adenocarcinoma or squamous cell carcinoma is 1000 times the expected occurrence rate in the general population. It is recommended that endo- scopic surveillance begin 15 20 years after caustic stricture injury, with endoscopy performed every 1 3 years thereafter [12 & ,28,40]. CONCLUSION Caustic ingestion remains a significant problem in children, despite continued efforts to educate the public about ways to avoid this preventable

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