2.1. Patients
The current study was a single-site retrospective study. The Ethics Committees of Shenzhen Children’s Hospital approved the study protocol. The medical records of 64 pediatric patients under 18 years of age, who were treated with EBD for benign esophageal stricture in Shenzhen Children's Hospital from January 2010 to December 2014, were investigated retrospectively. The patients treated by surgery or the use of adjuvant treatments were excluded.
All the patients were diagnosed with benign ES based on detailed history as obtained from the patient or parents, dysphagia symptoms, upper gastrointestinal radiography and endoscopic appearance. The dysphagia scoring system (12) was applied to the children older than 6 months. The score scaled from 0 to 4: 0, no dysphagia; 1, unable to swallow certain solids; 2, able to swallow soft foods; 3, able to swallow only liquids; 4, unable to swallow even liquids. The infants younger than 6 months were evaluated by clinical presentation and endoscopy. The follow-up period ranged from 36 to 60 months. The demographic features, features of the strictures and outcomes were recorded. The success rate, complications, response, and recurrence rate were comparatively evaluated, and the risk factors were analyzed.
2.2. Endoscopic technique
After written consent was obtained from the children’s parents, endoscopy and dilatation were performed under general anesthesia with endotracheal intubation. Firstly, the controlled radial expansion wire-guided balloon dilator (Boston Scientific, Cork, Ireland) was introduced and positioned across the stricture under the direct guidance of the endoscope (GIF-Q260J; Olympus, Tokyo, Japan), then the balloon was inflated with saline to achieve the desired pressure and maintained for 3 minutes, after that the pressure of the balloon was released for 3 minutes. Each dilatation session consisted of 2 to 3 three-minute multistep inflations of the balloon with incremental diameter until adequate dilatation was achieved. The length of the balloon is 5.5 cm, and the diameters range from 6 to 18 mm (Boston Scientific, Cork, Ireland. REF: M0058390, M0058400, M0058410, M0058420). The size of the balloon was chosen depending on the diameter of the esophageal stricture portion which was assessed under endoscopy - the diameter of the endoscope is 9 mm. The first dilation was usually performed with a balloon about 2-3 mm larger than the stricture. All the patients were followed up as outpatients after successful dilatation. The dilatation frequency was once every 3 - 4 weeks if symptoms of obstruction were present, after that the frequency was individualized to once every 4 - 12 weeks according to stricture appearance at endoscopy or patient complaints.
The treatment effectiveness was judged based on improvement of symptoms. It was considered as effective response if a patient had disappearance or relief of dysphagia or dysphagia score of 1 for children older than 6 months for at least 1 year after last dilatation. We defined failure as resistance to EBD (no alteration of stricture diameter when dilated). The return of dysphagia more than 1 year after the last EBD was considered as recurrence.
2.3. Statistical Analysis
Statistical presentation and analysis was conducted using Statistical package SPSS 19.0 (SPSS Inc., Chicago, USA). Continuous variables are expressed as the mean ± SD. The Student’s t-test was used for the comparison between groups; if the number of groups was 2 or more, the analysis of variance (ANOVA) was applied. Categorical variables were analyzed using the chi-square test. Spearman rank order correlations analysis, for nonparametric correlation, was applied to test correlations between variables. Two-tailed p-values less than 0.05 were considered statistically significant.