Endoscopic transesophageal biopsy in the posterior mediastinum using submucosal tunneling technology and novel homemade instruments.

BACKGROUND/AIMS: This animal study was performed to evaluate the feasibility and safety of endoscopic transesophageal biopsy by using submucosal tunneling technology novel homemade instruments in the posterior mediastinum. METHODOLOGY: In six survival pigs, a mid-esophageal mucosal incision and a 10-cm submucosal tunnel was created. The endoscope attached to homemade decompression tube was passed through the muscular layers into the posterior mediastinal space. The mediastinal compartment, lung, descending thoracic aorta, vertebra, and exterior surface of the esophagus will be identified, and mediastinal living tissue as lymph node biopsy will also be accomplished. During two survival weeks, blood test and temperature monitoring and chest radiograph and endoscopic examination were performed. RESULTS: The procedure was successfully completed in all six pigs. Mediastinal structures could be identified without difficulty by the transesophageal tunneling approach. Tissue as lymph nodes and pleural biopsy under direct visualization were easily accomplished. One pig died after operation due to an unexplained pneumothorax. At necropsy, apparent atelectasis was noted in the right lobe. After applying homemade drainage tube attached to the syringe, one pig with pneumothorax soon had restoration. There were no apparent ill effects in the survival pigs. CONCLUSIONS: Endoscopic transesophageal biopsy in the posterior mediastinum using a novel tunneling technology can provide excellent visualization of mediastinal structures. These procedures could be performed safely in pigs with short-term survival. Further study about immediate complications will be needed with a larger sample size and longer survival time.

Treatment with exogenous hydrogen sulfide attenuates hyperoxia-induced acute lung injury in mice.

The aim of this work was to test the effect of treatment with hydrogen sulfide (H2S) on hyperoxia-induced acute lung injury in mice. Mice were exposed to room air or 95 % O2, and treated with NaHS (intraperitoneal injection of 0.1 ml/kg/day of 0.56 mol/l NaHS). Treatment with H2S partly restored the reduced H2S levels in plasma and lungs of mice exposed to hyperoxia. Treatment with H2S attenuated hyperoxia-induced acute lung injury marked by reduced ratio of lung weight to body weight, ratio of lung wet weight to dry weight, and cell numbers and protein content in bronchoalveolar lavage (BAL) and decreased apoptosis. Treatment with H2S markedly prolonged the survival of mice under oxygen exposure. Treatment with H2S abated hyperoxia-induced oxidative stress marked by reduced malondialdehyde and peroxynitrite formation, reduced NADPH oxidase activity, enhanced translocation of nuclear factor E2-related factor (Nrf2) into nucleus and increased activity of HO-1. Treatment with H2S decreased IL-1ß, MCP-1, and MIP-2, and increased IL-10 expression in lungs of mice exposed to hyperoxia. Treatment with H2S decreased NFκB activity and iNOS expression in lungs, and reduced NOx content in BAL of mice exposed to hyperoxia. Treatment with H2S reduced lung permeability and suppressed VEGF release and VEGFR2 expression in lungs of mice under oxygen exposure. Treatment with exogenous H2S attenuated hyperoxia-induced acute lung injury through abating oxidative stress, suppressing inflammation, and reducing lung permeability in mice.

Temporary placement of a fully covered self-expandable metal stent in the pancreatic duct for aiding extraction of large pancreatic duct stones: preliminary data.

BACKGROUND AND AIM OF STUDY: Endoscopic clearance of large stones in the pancreatic duct (PD) is very difficult, even in patients undergoing stone fragmentation by extracorporeal shock wave lithotripsy. Placement of fully covered self-expandable metal stents (FCSEMSs) has not yet been reported to aid extraction of large PD stones. This aim of this study is to evaluate the technical success and safety of temporary placement of a FCSEMS in the PD to aid extraction of large PD stones. PATIENTS AND METHODS: Here, we report a pilot study and retrospective case series. Eight patients with chronic pancreatitis and large stones in the PD received endoscopic treatment. Eight symptomatic patients with more than three PD stones of large diameter (≥10 mm) were selected for FCSEMS placement and participation in this study. The patients' PD stones were located in the head, neck, and/or body of the pancreas and could not be cleared using a balloon catheter and basket. After placement of a FCSEMS (10 mm diameter) in the PD between 1 and 5 months (mean duration: 71 days), standard endoscopic maneuvers led to clearance of large PD stones. Technical success was defined as successful stent placement and the ability to achieve PD clearance in two endoscopic sessions. Complications were assessed according to consensus criteria. RESULTS: FCSEMSs were placed successfully in all patients and PD stones were all cleared easily from the dilated PD using the retrieval balloon and basket. There were no significant complications such as acute pancreatitis, hemorrhage, migration, or stent incarceration. At the 6-month follow-up, no residual stones were observed on pancreatography, and all patients were doing well, without any symptom recurrence. CONCLUSION: Temporary placement of an FSCEMS in the PD is a minimally invasive and feasible approach for aiding extraction of large PD stones.

New endoscopic classification system for biliary stricture after liver transplantation.

AIM: A new classification system for biliary stricture (BS) after liver transplantation (LT) is proposed, aiming to standardize endoscopic treatment for this condition. METHODS: Data were retrospectively collected from patients who had undergone endoscopic retrograde cholangiography after LT, and who provided endoscopy images clear enough to reveal the biliary system. Images were classified separately by two endoscopists, who discussed and resolved any disputed findings. From these images, a new classification system is proposed (Ling classification): type A, normal biliary structure; type B, anastomotic stricture and normal intrahepatic biliary structure; type C, narrow and stiff intrahepatic biliary structure or beaded intrahepatic biliary structure or intrahepatic biliary cast without anastomotic stricture; type D, narrow and stiff intrahepatic biliary structure or beaded intrahepatic biliary structure or intrahepatic biliary cast with anastomotic stricture. RESULTS: Analysis involved 93 patients: 76 men and 17 women, median age 54 years (range, 12-69 years). Type B was the most commonly observed BS after LT, accounting for 44 cases (47.3%). Type A, the least commonly observed type, accounted for nine (9.7%), type C for 22 (23.7%) and type D for 18 (19.3%) cases. CONCLUSION: A new endoscopic classification system for BS after LT is proposed, to help determine the most appropriate treatment for patients with each type of stricture.

[Comparison of endoscopic submucosal tunnel dissection with endoscopic submucosal dissection for large esophageal superficial neoplasms].

OBJECTIVE: To compare the safety and efficiency of endoscopic submucosal tunnel dissection (ESTD) and endoscopic submucosal dissection (ESD) for large esophageal superficial neoplasms. METHODS: A total of 235 consecutive patients undergoing endoscopic resection for esophageal neoplasms between October, 2010 and June, 2013 in our endoscopy center were analyzed retrospectively. According to the inclusion and exclusion criteria, 29 patients receiving ESTD or ESD for large esophageal superficial neoplasms were enrolled for data analysis. RESULTS: Of the 29 patients, 11 underwent ESTD and 18 received ESD. The dissection speed of ESTD was significantly higher than that of ESD (22.4∓5.2 mm(2)/min vs 12.2∓4.0 mm(2)/min, P<0.05). Despite a similar en bloc rate between the two groups (100% [11/11] vs 88.9% [16/18], P>0.05), the radical curative rate of ESTD was significantly greater than that of ESD (81.8% [9/11] vs 66.7% [12/18], P<0.05). No serious bleeding or perforation occurred in the patients except for 1 in ESD group with intraoperative bleeding, which was managed with hemostatic forceps. Eight patients had postoperative esophageal strictures in relation with circumferential extension and the longitudinal length (P<0.05). CONCLUSION: ESTD is a safe and effective alternative for large esophageal superficial neoplasms with a shortened operative time, a higher dissection speed and a higher radical curative rate in comparison with ESD, but postoperative esophageal strictures should be closely monitored especially for lesions more than 3/4 of the circumferential extension or exceeding 50 mm.

[Comparison of peroral endoscopic myotomy with transverse entry incision versus longitudinal entry incision for achalasia].

OBJECTIVE: To compare the safety and efficiency of transverse-incision peroral endoscopic myotomy (POEM) with longitudinal-incision POEM. METHODS: POEM, with a transverse or longitudinal entry incision, was performed in 53 consecutive patients with confirmed achalasia (AC) between December 2010 and September 2012. Data of those patients was collected including the time spent for different procedures and complications. RESULTS: All the 53 patients underwent POEM successfully, among whom 41 patients had a transverse entry incision and 12 had a longitudinal incision. Treatment success (Eckardt score≤3) with a follow-up for 3-24 months (median 5 month) was achieved in 96.2% of the cases (mean score pre-treatment vs. post-treatment: 7.5 vs 0.6, P<0.001). The whole operation time of transverse-incision group was slightly shorter than that of longitudinal-incision group (65.0∓18.0 min vs 74.1∓18.2 min, P=0.142), but it took much less time in tunnel built-up and muscle dissection in the transverse-incision group (36.3∓9.0 min vs 45.4∓10.5 min; 10.2∓4.6 min vs 15.5∓5.5 min, P<0.05). In addition, patients in transverse incision group were much less likely to develop pneumatosis- related complications [9.8% (4/41) vs 41.7% (5/12), P<0.05). No serious complications occurred in these two groups such as pleural effusion, mediastinitis or digestive tract fistula. CONCLUSIONS: POEM with a transverse entry incision can significantly decrease the operation time and reduce the incidence of pneumatosis-related complications while obviously relieving the symptoms.