Cryotherapy for removal of an embedded, partially covered esophageal stent.

Video 1Cryotherapy for removal of an embedded, partially covered esophageal stent.

EUS for pancreatic cystic neoplasms: The roadmap to the future is much more than just a few shades of gray.

Pancreatic cystic and neoplasms are being diagnosed with increasing frequency. Accurate diagnosis and determination of benign versus malignant lesions is crucial for determining need for surveillance versus surgery or endoscopic therapy as well as avoiding unnecessary surgery in cysts with no malignant potential. Tumor markers such as KRAS and GNAS hold promise, but which molecular marker or a combination of markers is most useful and cost effective remains to be seen. Advanced imaging with confocal laser endomicroscopy can serve as an optical biopsy and play a part in the diagnostic algorithm. Microforceps aided biopsy of pancreatic cyst wall and tumor contents hold great promise as they allow direct tissue acquisition. Much progress has been made in the role of EUS guided evaluation of pancreatic cystic neoplasms over the last several years, and with the advances enumerated above, the future is more than just a few shades of gray. Future studies should include prospective multi-arm trials of microforceps biopsy versus conventional EUS-FNA and use of biochemical and molecular markers, confocal laser endomicroscopy or a combination thereof to determine best approach to pancreatic cystic neoplasms. In Osler's words, 'Medicine is a science of uncertainty and an art of probability'. Incorporation of advanced imaging and molecular markers into a new diagnostic algorithm with subsequent validation through retrospective and prospective studies has the potential to increase diagnostic accuracy and guide optimal management of patients and improve outcomes.

Utility of clinical suspicion and endoscopic re-examination for detection of esophagogastric perforation after pneumatic dilation for achalasia.

BACKGROUND AND STUDY AIMS: Esophagrams are often obtained routinely after pneumatic balloon dilation for achalasia, even in asymptomatic patients, as there is a risk of postprocedure esophagogastric perforation, which is a potentially life-threatening complication. The aim of this study was to determine whether the combination of a clinical suspicion of perforation and endoscopic re-examination after pneumatic dilation for achalasia can detect esophagogastric perforation, and thereby preclude the need for routine esophagrams in all patients. PATIENTS AND METHODS: All patients who underwent pneumatic dilation between January 2002 and June 2012 at our single tertiary referral center were identified retrospectively. Procedures were categorized into two groups: Group 1 underwent routine esophagograms after pneumatic dilation, and Group 2 underwent esophagograms only if there was a clinical suspicion of perforation. The detection rate of esophageal perforation after pneumatic dilation was compared between the two groups. RESULTS: A total of 119 achalasia dilation procedures were performed in 70 patients. Group 1 included 49/119 procedures (41.2 %), all of which were followed by routine esophagograms. Group 2 included 70/119 procedures (58.8 %), 12 of which were followed by esophagograms based on a clinical suspicion of perforation. No esophageal perforations were found in Group 1, whereas three were found in Group 2. No perforations occurred in the 58 procedures that were not followed by esophagograms. The overall rate of perforation was 3/119 (2.5 %). CONCLUSIONS: Esophagrams obtained routinely after pneumatic dilation for achalasia did not reveal unsuspected esophagogastric perforations. No esophageal perforations were missed after procedures that were not followed by esophagograms. Obtaining an esophagram only in cases of clinical suspicion of perforation and endoscopic evaluation may be an alternative to routine esophagograms in patients undergoing pneumatic dilation for achalasia.

Endoscopic Optical Coherence Tomography (OCT): Advances in Gastrointestinal Imaging.

In the rapidly evolving field of endoscopic gastrointestinal imaging, Optical Coherence Tomography (OCT) has found many diverse applications. We present the current status of OCT and its practical applications in imaging normal and abnormal mucosa in the esophagus, stomach, small and large intestines, and biliary and pancreatic ducts. We highlight technical aspects and principles of imaging, assess published data, and suggest future directions for OCT-guided evaluation and therapy.

Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos).

BACKGROUND: Radiofrequency ablation (RFA) is effective for treating Barrett's esophagus (BE) but often involves multiple endoscopy sessions over several months to achieve complete response. OBJECTIVE: Identify structural markers that correlate with treatment response by using 3-dimensional (3-D) optical coherence tomography (OCT; 3-D OCT). DESIGN: Cross-sectional. SETTING: Single teaching hospital. PATIENTS: Thirty-three patients, 32 male and 1 female, with short-segment (<3 cm) BE undergoing RFA treatment. INTERVENTION: Patients were treated with focal RFA, and 3-D OCT was performed at the gastroesophageal junction before and immediately after the RFA treatment. Patients were re-examined with standard endoscopy 6 to 8 weeks later and had biopsies to rule out BE if not visibly evident. MAIN OUTCOME MEASUREMENTS: The thickness of BE epithelium before RFA and the presence of residual gland-like structures immediately after RFA were determined by using 3-D OCT. The presence of BE at follow-up was assessed endoscopically. RESULTS: BE mucosa was significantly thinner in patients who achieved complete eradication of intestinal metaplasia than in patients who did not achieve complete eradication of intestinal metaplasia at follow-up (257 ± 60 µm vs 403 ± 86 µm; P < .0001). A threshold thickness of 333 µm derived from receiver operating characteristic curves corresponded to a 92.3% sensitivity, 85% specificity, and 87.9% accuracy in predicting the presence of BE at follow-up. The presence of OCT-visible glands immediately after RFA also correlated with the presence of residual BE at follow-up (83.3% sensitivity, 95% specificity, 90.6% accuracy). LIMITATIONS: Single center, cross-sectional study in which only patients with short-segment BE were examined. CONCLUSION: Three-dimensional OCT assessment of BE thickness and residual glands during RFA sessions correlated with treatment response. Three-dimensional OCT may predict responses to RFA or aid in making real-time RFA retreatment decisions in the future.

Cervical inlet patch-optical coherence tomography imaging and clinical significance.

AIM: To demonstrate the feasibility of optical coherence tomography (OCT) imaging in differentiating cervical inlet patch (CIP) from normal esophagus, Barrett's esophagus (BE), normal stomach and duodenum. METHODS: This study was conducted at the Veterans Affairs Boston Healthcare System (VABHS). Patients undergoing standard esophagogastroduodenoscopy at VABHS, including one patient with CIP, one representative patient with BE and three representative normal subjects were included. White light video endoscopy was performed and endoscopic 3D-OCT images were obtained in each patient using a prototype OCT system. The OCT imaging probe passes through the working channel of the endoscope to enable simultaneous video endoscopy and 3D-OCT examination of the human gastrointestinal (GI) tract. Standard hematoxylin and eosin (H and E) histology was performed on biopsy or endoscopic mucosal resection specimens in order to compare and validate the 3D-OCT data. RESULTS: CIP was observed from a 68-year old male with gastroesophageal reflux disease. The CIP region appeared as a pink circular lesion in the upper esophagus under white light endoscopy. OCT imaging over the CIP region showed columnar epithelium structure, which clearly contrasted the squamous epithelium structure from adjacent normal esophagus. 3D-OCT images obtained from other representative patients demonstrated distinctive patterns of the normal esophagus, BE, normal stomach, and normal duodenum bulb. Microstructures, such as squamous epithelium, lamina propria, muscularis mucosa, muscularis propria, esophageal glands, Barrett's glands, gastric mucosa, gastric glands, and intestinal mucosal villi were clearly observed with OCT and matched with H and E histology. These results demonstrated the feasibility of using OCT to evaluate GI tissue morphology in situ and in real-time. CONCLUSION: We demonstrate in situ evaluation of CIP microstructures using 3D-OCT, which may be a useful tool for future diagnosis and follow-up of patients with CIP.

Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos).

BACKGROUND: Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples. OBJECTIVE: To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy. DESIGN: Cross-sectional study. SETTING: Single teaching hospital. PATIENTS: Twenty-six male and 1 female white patients with BE undergoing RFA treatment. INTERVENTIONS: 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia (pre-CE-IM group) and in 16 patients after CE-IM (post-CE-IM group). MAIN OUTCOME MEASUREMENTS: Prevalence, size, and location of buried glands relative to the squamocolumnar junction. RESULTS: 3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and standard biopsy and sufficient imaging depth for detecting buried glands. Based on 3D-OCT results, buried glands were found in 72% of patients (13/18) in the pre-CE-IM group and 63% of patients (10/16) in the post-CE-IM group. The number (mean [standard deviation]) of buried glands per patient in the post-CE-IM group (7.1 [9.3]) was significantly lower compared with the pre-CE-IM group (34.4 [44.6]; P = .02). The buried gland size (P = .69) and distribution (P = .54) were not significantly different before and after CE-IM. LIMITATIONS: A single-center, cross-sectional study comparing patients at different time points in treatment. Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo. CONCLUSION: Buried glands were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation.

Intraoperative NOTES endosonography and identification of mock hepatic lesions.

PURPOSE: Intraoperative ultrasound is commonly used during standard transabdominal surgery. The feasibility of endoscopic ultrasound (EUS) through Natural Orifice Translumenal Endoscopic Surgery (NOTES) for identification of abdominal lesions with a flexible echoendoscope has not been studied. AIM: To test the feasibility of NOTES-EUS for abdominal exploration and identification of mock hepatic lesions. METHODS: Five pigs underwent transvaginal or transcolonic NOTES and endosonographic exploration. In 3 anesthetized pigs, mock hepatic lesions were created and NOTES-EUS was then performed to identify these mock lesions. Necropsy was performed in all cases. RESULTS: All target organs were consistently identified by NOTES-EUS in all animals. Mock hepatic lesions were successfully created in 3 animals and were able to be located by NOTES-EUS. No complications were observed at necropsy. CONCLUSIONS: Abdominal exploration and localization of mock lesions by NOTES-EUS is technically feasible. As natural orifice surgery evolves, intraoperative NOTES-EUS would be an essential addition to the NOTES armamentarium.