the target lesion. ESD using the SB knife was performed safely and easily, and reduced unexpected incisions. Our aim was to retrospectively examine the safety.
Abstracts
Su1504 Endoscopic Submucosal Dissection of Superficial Esophageal Squamous Cell Neoplasia by Scissors-Like Forceps: A Safer Technique Haruka Fujinami, Takahiko Kudo, Ayumu Hosokawa, Toshiro Sugiyama Department of gastroenterology, University of Toyama, Toyama, Japan Background and Aims: Endoscopic submucosal dissection (ESD) has recently been accepted as an established treatment for superficial squamous cell neoplasia in Japan. It is reported that the rates of en bloc resection and perforation accompanied by mediastinal emphysema were 100% and 4%-7%, respectively. ESD of the esophagus is an anatomically difficult procedure. The wall of the esophagus is thinner than that of the stomach and the esophagus is located in the superior and posterior mediastina; hence life-threatening complications could occur easily. Conventionally, we used a Hook knife (KD620LR; Olympus, Tokyo, Japan) for ESD of esophageal squamous cell carcinoma. The drawback of this knife is that it is not covered with an insulator, which leads to unexpected incisions resulting in perforation and mediastinal emphysema. Therefore, safer procedures are required for esophageal ESD. The SB knife (MD47704; Sumitomo Bakelite, Tokyo, Japan), which is a scissors-like shaped forceps, can be used for excision by accurately gripping the submucosal tissue of the target lesion. ESD using the SB knife was performed safely and easily, and reduced unexpected incisions. Our aim was to retrospectively examine the safety and efficacy of ESD using two different knives. Subjects and Methods: ESD was performed on 25 lesions from 25 patients with superficial esophageal squamous cell neoplasia from September 2006 to June 2010. The patients were divided into two groups according to the type of knife used; 19 patients were operated using the hook knife (Hook group) and 6 patients were operated using the SB knife (SB group). We evaluated operating time, size of lesion, rate of en bloc resection, and rate of perforation in each group. Results: In the Hook and SB groups, the average size of lesions was 5.77 ⫾ 5.18 mm2 and 7.36 ⫾ 3.64 mm2 (not statistically significant), operating time was 107.4 ⫾ 58.2 minutes and 72.7 ⫾ 23.2 minutes, rate of en bloc resection was 89.4% (17/19) and 100.0% (6/6), and rate of perforation was 10.6% (2/19) and 0% (0/6), respectively. Conclusions: ESD of esophageal superficial squamous cell neoplasia is an anatomically difficult procedure. Therefore, accurate mucosal incision and submucosal dissection of the target lesion are necessary. From the viewpoint of accuracy and safety, the SB knife provided superior performance compared to the Hook knife in ESD of the esophagus.
SB knife is shaped scissors-like forceps.
Su1505 Preliminary Report of a Prospective Study of Cryospray Ablation With Liquid Nitrogen Using Surgical Resection Specimens to Determine Treatment Effect, Depth of Injury and Side Effects Afonso C. Ribeiro, Pablo A. Bejarano, Lynne Sparling, Dido Franceschi, Bach Ardalan, Alan S. Livingstone University Of Miami School of Medicine, Miami, FL Introduction: This study provides histologic documentation of cryospray ablation (CSA) affect on human esophageal tissue at two different doses. CSA is a noncontact method of destroying unwanted tissue using low-pressure liquid nitrogen. The rapid freezing and thawing associated with CSA evokes significant
cellular damage through a variety of pathways leaving the stroma essentially unaffected, avoiding the potential for mechanical injury attendant to other thermal modalities. Methods and Procedures: CSA was administered to unaffected esophageal tissue during a standard esophagogastroduodenoscopy seven days prior to a cancer related esophagectomy. All patients received only preoperative chemotherapy. Study design includes a comparison of two doses of CSA: four cycles of 10 sec versus two cycles of 20 sec. Pathologic inspection was performed along a 20mm segment at site of injury by two different pathologists. The area was analyzed at 5mm intervals from the center of injury: center, 5mm above and below center and 10mm above and below center (5 stations). Depth of cryonecrosis and inflammation were determined at each of the five stations. Patients were contacted at 48-72hrs to monitor for side effects. Results: Four patients have completed the study protocol, two in each arm. After seven days of CSA, there was no evidence of scarring, stricturing or perforation. The stroma was not affected by CSA. Complete mucosal ablation was achieved in all four patients at the entire mucosal length analyzed. Cryonecrosis was wider and deeper in the 20 sec treated patients. In patients treated for 10 sec, cryonecrosis reached submucosa (SM) in 5 of 10 sites of analysis (50%). In patients treated for 20sec, cryonecrosis reached SM in 9 of 10 sites (90%). In one patient treated for 20 sec. cryonecrosis/inflammatory reaction was transmural reaching adventitia at the center of spray without evidence of perforation. Depth of inflammation reached SM or beyond in 9 of 10 sites (90%) in the 10 sec patients and in all patients treated for 20 sec (100%). Side effects included dysphagia and moderate chest pain, both of which resolved spontaneously and required no medications. Adjacent organs were not affected and CSA did not affect the patient’s surgical outcome. Conclusions: Initial results from this study demonstrate transmural esophageal injury without evidence of perforation or stricture. Based on this limited sample size, 20 sec. x 2 sprays induce a more consistent, deeper injury pattern than 10 seconds x 4 sprays. Deeper cryonecrosis with 20 sec. also support treatment of advanced disease in other reported uses of cryoablation.
Su1506 Efficacy and Safety of the Fully Covered Esophageal Wallflex Stent: A Prospective Study Mihir S. Wagh, Christopher E. Forsmark, Shailendra S. Chauhan, Peter V. Draganov Division of Gastroenterology, University of Florida, Gainesville, FL Background: Various self-expandable metal esophageal stents are currently available for esophageal endotherapy. Fully covered esophageal stents have shown promising results in the endoscopic management of benign and malignant esophageal diseases. However, there is no data on the use and safety of the fully covered esophageal Wallflex stent (Boston Scientific, Natick, MA). Aim: To assess the efficacy and safety of the fully covered esophageal Wallflex stent in the endoscopic management of esophageal diseases. Methods: This prospective study was approved by the Institutional Review Board at our tertiary care referral center. Patients undergoing upper endoscopy for esophageal stent placement were enrolled in the study. Clinical, endoscopic, radiological, surgical and pathological records were maintained as required for clinical care and for the study. Dysphagia score was recorded before and after stent therapy. All stents placed for benign indications were removed or exchanged at 6 weeks per protocol unless side-effects or complications required earlier endoscopy. Response was based on the following parameters: (1) improvement in dysphagia score, (2) stricture or fistula resolution based on endoscopic assessment, radiographic imaging (CT scan, esophagram) and clinical status. Results: 24 fully covered esophageal Wallflex stents were placed in 14 patients (8 male, 57%; mean age 62.6, range 27 - 82 years) from 12/2009 - 8/2010. Indications for stent placement included strictures (1 radiation, 2 anastomotic, 1 malignant) in 4/14, esophageal fistulas (3 malignant, 1 benign radiation) in 4/14, and benign esophageal perforations in 6/14 patients. Stents were successfully placed in all 14 patients. Mean follow-up was 3.25 months with a range of 1-7 months. Mean dysphagia score of 4 (complete dysphagia) prior to stent placement in patients with dysphagia in the stricture group improved to 1.75 (score 1⫽ able to eat some solid food) with stent therapy; however strictures recurred after stent removal in all 3 patients with benign strictures and required subsequent endoscopic dilation. Esophageal leak resolved in 3/4 (75%) patients with fistulas after stent placement while perforations resolved in 4/6 (67%) patients. Overall response was seen in 8/14 (57%) patients. Stent removal was successful in all cases where it was attempted. Complications were seen in 7/14 (50%) patients and included chest pain in 4/14 (29%), tissue overgrowth at the ends of the stent in 3/14 (21%) and migration in 5/14 (36%). Conclusion: Though limited by small number of patients and short follow-up, this study shows that endotherapy with the fully covered esophageal Wallflex stent has moderate efficacy with a tolerable safety profile. Response rate in patients with esophageal perforations or fistulas was better than in patients with benign refractory strictures.
AB286 GASTROINTESTINAL ENDOSCOPY Volume 73, No. 4S : 2011
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