Abstracts of the 20 th National Congress of Digestive Diseases / Digestive and Liver Disease 46S (2014) S1–S144 S19 OC.07.4 PERORAL ENDOSCOPIC MYOTOMY FOR THE TREATMENT OF ACHALASIA IN CHILDREN G. Gigante *,1 , P. Familiari 1 , M. Marchese 2 , I. Boskoski 1 , V. Perri 1 , A. Tringali 1 , V. Bove 1 , M. Campanale 1 , G. Costamagna 1 1 Unità Operativa di Endoscopia Digestiva Chirurgica, Policlinico Gemelli Roma, Italy; 2 Unità Operativa di Endoscopia Digestiva, L’Aquila, Italy Background and aim: Esophageal achalasia is very rarein children, with an estimated annual incidence of 0.02-0.11 cases per 100,000. Peroral Endo- scopic Myotomy (POEM) has been recently introduced in clinical practice for the treatment of esophageal achalasia. Published studies demonstrated a very low complication rate and excellent results at short term follow-up, in adults. POEM has been seldom used in pediatric patients. In this series we describe seven children with achalasia who underwent POEM. Material and methods: From January 2012 to October 2013, 7 children (4 female, median age 11.14 [range 6–16]) with achalasia underwent POEM. Eckardt score (ECKs) was used for symptoms evaluation before the procedure and during the follow-up. Esophageal manometry, and EGDS were performed during the follow-up at regular intervals (3, 6, 12 months). Esophageal pH- metry was performed after 6- or 12-months. One child had already undergone a pneumatic dilation with 18 mm balloon. Results: POEM was successfully completed in all 7 cases. Mean symptoms duration before POEM was 17,4 months (4-60 months). Mean preoperative basal LES pressure and 4sIRP were 43.3 mmHg (29-83 mmHg) and 31.7 mmHg (11-51 mmHg). Mean preoperative ECKs was 6 (4-10). Mean operat- ing time was 63 minutes (49-82 minutes). The mean length of the submucosal tunnel was 14.3 cm. Myotomy length mean was 10.3 cm (range 8–12 cm). The first two children completed a 18 month follow-up, complete symptoms relief (ECKs = 0) after the procedure was documented in both patients at 18 months, with a significant reduction of the basal LES pressure at manome- try (10 and 15 mmHg, respectively), 24-hour esophageal pH-metry did not demonstrate pathological gastroesophageal reflux (total reflux time 2.4% and 3.7%). Patients gained weight and grew regularly. The follow-up of the other 5 patient is still ongoing. However, at one month follow-up a significant drop of the Eckardt score (from 6 to 0) was documented. Conclusions: Our results confirm the feasibility, safety and efficacy of POEM in children. In the two patients who completed a 12-month follow-up, complete symptoms relief was documented, as well as a significant drop of the basal LES pressure. Larger studies with a longer follow-up are necessary, before the role of POEM for the treatment of pediatric achalasia can be definitely established. OC.07.5 COLORECTAL ENDOSCOPIC SUBMUCOSAL DISSECTION: RESIDUAL/RECURRENT LESIONS VERSUS PRIMARY LESIONS G. Andrisani * , L. Petruzziello, G. Vitale, S. Greco, S. Cristiano, G. Costamagna Digestive Endoscopy Unit, Catholic University, Rome, Italy Background and aim: Residual/locally recurrent lesions may occur after endoscopic resection: endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) or after transanal endoscopic microsurgery (TEM) for rectal lesions. ESD may be useful for resection of scar-embedded lesions, not lifted by standard injection of saline solution, but may be more technically difficult. We evaluated the feasibility and safety of ESD, as a salvage therapy for residual/locally recurrent lesions compared to primary lesions. Material and methods: From January 2011 to March 2013 we performed 30 colonic ESD. Fifteen patients were on the first endoscopic treatment and the remaining fifteen had residual/recurrent lesions (median diameter of 21 mm) and have received at least an attempt at endoscopic resection using standard techniques including snare polypectomy, EMR or argon plasma coagulation, or TEM (5/15). The tumor size, the procedure duration, complications and early recurrence rate were compared between the two groups. Results: Procedure time was similar between groups (70±22 min vs 72±35 min). The lesions were significantly smaller (23±9 mm vs 35±15 mm; P<0.05) in the residual/locally recurrent group, compared with primary lesions. Imme- diate bleeding rate was significantly higher in primary lesions group (46.6% vs 6.6%; P<0.05). However, there were no cases of delayed bleeding in both groups. Intraprocedural perforations were observed only in residual/locally recurrent group (3/15: 20%): surgery was needed in one patient, while two patients were managed using endoclips. Early recurrence, evaluated at three months, was similar between groups (20%). Conclusions: Endoscopic submucosal dissection for residual/locally recurrent lesions was more difficult with higher risk of perforation due to presence of scar. However, the presence of lesions of smaller size and the low risk of intra-procedural bleeding, may recommend this procedure for scar-embedded lesions instead of surgical resection. OC.07.6 HYBRID-KNIFE ASSISTED-POEM FOR PATIENTS WITH ESOPHAGEAL MOTILITY DISTURBANCES. PRELIMINARY RESULTS FROM A SINGLE CENTER PROSPECTIVE STUDY A. Repici * , U. Fumagalli, M. Ceolin, E. Carlani, A. Anderloni, S. Carrara, L. Barbieri, R. Rosati istituto Clinico Humanitas, Rozzano (MI), Italy Background and aim: Peroral endoscopic myotomy (POEM) is a novel approach for esophageal myotomy. Two different techniques for tunneling and myotomy are TT-knife and Hybrid-knife (HK). HK is a novel technology device which allows to inject the submucosa and cut/coagulate with the same instrument. Aim: To investigate the feasibility and safety of POEM with HK. Material and methods: Consecutive patients (pt) with esophageal dismotility on high-resolution manometry were considered for the study. Primary out- come: symptom relief at 3 months (Eckhard score ≤3). Secondary outcomes: procedure-related adverse events, lower esophageal sphincter (LES) pressure on manometry, and medication use before and after POEM. POEM performed under general anesthesia with standard upper GI scope and distal attachment on the tip. After submucosal injection with HK, a mucosal incision was made on the anterior side of the esophagus about 15 cm above the gastroesophageal junction (GEJ). A long submucosal tunnel was created to extend below the GEJ. The endoscopic myotomy started 10cm above and extended 2cm below the GEJ. Results: 12 patients (10M/3F), mean age 57y (range 44–67y) were included in the study. Primary diagnosis: achalasia a (10pt), diffuse esophageal spasm (1pt), nutcracker esophagus (1pt). Two patients have been already treated by pneumatic dilation, one by Heller myotomy and two with nifedipine. POEM was successfully completed in all patients. Mean operating time was 72 min (range 66–100). No early complications were recorded. Mean hospitalization time was 3.6 days (2-9). The long stays were due to persistent postoperative pneumomediastinum of pneumoperitoneum. A 3-month follow-up was com- pleted for all patients. Treatment success (Eckhard score ≤3) was achieved in 91% of cases (mean score pre- vs. post-treatment (7.8 vs. 0.9); P < 0.001). Mean LES pressure was 27.2 mm Hg pre-treatment and 11.8 mm Hg post- treatment (P<0.001). No patient developed symptoms of gastro-esophageal reflux after treatment, but one patient was found to have an erosive lesion (LA grade A) on follow-up endoscopy. Conclusions: HK assisted POEM is a promising new treatment for achalasia resulting in short-term symptom relief in >90% of cases. The use of HK is associated with a short procedure time and absence of early or late adverse events.