Recurrence after endoscopic mucosal resection-therapy failure?

PURPOSE: To evaluate the success and complication rates of endoscopic mucosal resections (EMR) for large flat adenomas and to identify risk factors for adenoma recurrence. METHODS: We evaluated all consecutive patients treated with EMR at our institution between 2003 and 2005 that fulfilled the following criteria: >10-mm diameter, Paris 0-Is and 0-IIa-c, and endoscopic follow-up. We conducted univariate analysis and multivariate analysis using a non-stratified logistic regression model to identify possible influencing factors. RESULT: In a median follow-up period of 6 years, we analyzed 177 EMR procedures, with a mean size of 21 mm. The majority of the resections were in the right colon. Recurrence occurred in 29 patients. Further treatment of patients with recurrence was endoscopic in 27 patients, whereas 1 patient was treated with transanal endoscopic microsurgery and one underwent surgery. The variables influencing the multivariate model were resection technique, immediate complication age, and histology. CONCLUSIONS: We show that EMR can achieve a long-term clearance of large flat adenomas. A recurrence after EMR does not equal to failed therapy. The possibility of recurrence has to be considered in the clinical implementation of EMR. An important part of the stratifying factors for follow-up is the procedural assessment of the effectiveness of the resection and the resection technique.

Fluctuating ideal-gas lattice Boltzmann method with fluctuation dissipation theorem for nonvanishing velocities.

Current implementations of fluctuating ideal-gas descriptions with the lattice Boltzmann methods are based on a fluctuation dissipation theorem, which, while greatly simplifying the implementation, strictly holds only for zero mean velocity and small fluctuations. We show how to derive the fluctuation dissipation theorem for all k, which was done only for k=0 in previous derivations. The consistent derivation requires, in principle, locally velocity-dependent multirelaxation time transforms. Such an implementation is computationally prohibitively expensive but, with a small computational trick, it is feasible to reproduce the correct FDT without overhead in computation time. It is then shown that the previous standard implementations perform poorly for non vanishing mean velocity as indicated by violations of Galilean invariance of measured structure factors. Results obtained with the method introduced here show a significant reduction of the Galilean invariance violations.

Transgastric appendicectomy.

BACKGROUND: Experimental studies and small anecdotal reports have documented the potential and feasibility of transgastric appendicectomy. This paper reports the results of the new technique in a selected group of patients. METHODS: From April 2010 transgastric appendicectomy was offered to all patients with acute appendicitis, but without generalized peritonitis or local contraindications. RESULTS: Of 111 eligible patients 15 agreed to undergo the transgastric operation. After conversion of the first case to laparoscopy because of severe inflammation and adhesions, the following 14 consecutive transgastric procedures were completed. Two patients with initial peritonitis required laparoscopic lavage 4 days after transgastric appendicectomy, but no leaks were detected at the appendiceal stump or stomach. CONCLUSION: These preliminary results have shown the feasibility of this innovative procedure. Additional studies, however, are required to demonstrate the specific advantages and disadvantages of this approach, and define its role in clinical surgery.

Temporary cystogastrostomy with self-expanding metallic stents for pancreatic necrosis.

Conventional endoscopic drainage of symptomatic pancreatic pseudocysts has its limitations when the content of the collection is nonfluid. This leads to obstruction of placed flap stents; it requires the placement of an irrigation catheter and repeated implantation of several stents. Herein we describe the temporary use of a special self-expanding partially covered metal mesh stent, which was designed to keep the pancreaticogastrostomy open for drainage of walled-off necrosis and for further endoscopic necrosectomies. The stent has a diameter of 20-25 mm and a length of 50 mm and was placed following the first transgastric removal of necrotic masses. After a treatment period of 7-11 days involving 2-3 endoscopic procedures we achieved clinical success, defined as complete removal of necrotic masses, in all cases without major complications.

Endoscopic application of hemostatic thrombin-gelatin matrix (FloSeal) in anticoagulated pigs.

Flexible endoscopy is the method of choice for the diagnosis and therapy of upper gastrointestinal bleeding, but there are still problems during therapy of patients with coagulation disorders. FloSeal((R)) is a hemostatic matrix largely independent of the body's own clotting system. A newly developed endoscopic applicator for FloSeal((R)) was tested in a survival study on pigs with impaired clotting. In a total of eight pigs ulcerous lesions Forrest Ib were induced and the bleeding stopped by applying FloSeal((R)). Thirty minutes before intervention six pigs were given full weight-adjusted heparinization or a maximum dose of ASS in advance. The Hb course was monitored over the next 48 hours and a postmortem examination was performed. In each case, FloSeal((R)) was successfully applied and all bleedings could be stopped. In both groups (except the control group) spontaneous extraintestinal bleeding occurred, but in only one case in the ASS group a gastrointestinal bleeding happened. The Hb course was stable in all other animals. FloSeal((R)) can also be used endoscopically using the applicator being presented here for the first time. It is suited for primary hemostasis of excavated sources of bleeding especially in situations where coagulation is impaired.

Comparison of standard endoscopic submucosal dissection (ESD) versus an optimized ESD technique for the colon: an animal study.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a promising therapeutic technique for en bloc resection of large gastrointestinal tumors. However, this technique has disadvantages such as a long intervention time, complexity of the procedure, and a higher rate of complications. The primary aims of the study were to show the feasibility of ESD in the pig colon and to evaluate a new ESD technique comprising the use of a newly developed hybrid knife for colon procedures combining RF (radiofrequency) application and a distance-dependent water-jet application. MATERIALS AND METHODS: ESD was conducted at three different locations in the colon according to the computer-generated randomization list, using either the standard technique (injection needle, flex knife, and hook knife as therapeutic instruments and DRY CUT and SWIFT COAG as RF currents), or the new ESD technique (hybrid knife as the therapeutic instrument combined with the new cutting mode ENDO CUT D) in 12 healthy pigs. The perforation and bleeding rates were documented and statistically analyzed. Intervention time, resected specimen size, thermal and mechanical damage of the resection bed, and number of instrument changes required were also recorded. RESULTS: A total of 16 and 18 ESD procedures were performed by the standard and new techniques, respectively. Complete en bloc resection was achieved in all cases. The standard ESD technique showed a perforation rate of 25 % (4/16) whereas the new ESD technique resulted in a 5.5 % perforation rate (1/18) ( P = 0.035); bleeding rates were similar. The new ESD technique was significantly safer compared with the standard ESD technique. CONCLUSIONS: A new ESD technique for the successful en bloc resection in thin-walled regions such as pig colon has been described. This procedure is as effective as the standard procedure but is easier to handle and significantly safer.

Endoscopic closure of the natural orifice transluminal endoscopic surgery (NOTES) access site to the peritoneal cavity by means of transmural resorbable sutures: an animal survival study.

BACKGROUND AND STUDY AIMS: Endoscopic closure of the transgastric access site is still a critical area of active research and development into natural orifice transluminal surgery (NOTES). To date, no endoscopic technique has utilized resorbable transmural sutures for closure of the NOTES gastrostomy. MATERIAL AND METHODS: Endoscopic gastrostomy closure by means of resorbable sutures was performed in ten female domestic pigs in an animal survival study. Peritoneal cavity access was gained through the anterior gastric wall using the percutaneous endoscopic gastrostomy (PEG) technique and an 18-mm balloon dilator. NOTES exploration of the gallbladder and tubal ligation were performed prior to endoscopic gastrostomy closure. Necropsy was performed 3 weeks post procedure. RESULTS: Mean suturing time was 26 minutes (range 14 - 35 minutes). In total 90 % (9/10) of gastrostomy closures were performed by means of two transmural resorbable sutures. One gastrostomy was closed using a single resorbable suture. One case of gallbladder perforation occurred during peritoneoscopy and the pig was sacrificed due to subsequent peritonitis 2 days after the procedure. All other pigs (9/10) were found to be healthy 3 weeks after the NOTES procedure and were sacrificed as planned per protocol. Of all the 17 sutures that were applied in the remaining nine pigs, 16 (94 %) had been absorbed, releasing the pledgets intraluminally. During laparotomy no signs of injury to adjacent organs were found in any of these nine animals. In 8/10 pigs (80 %) the gastrostomy site did not burst with pressures exceeding 100 mmHg. Two suturing sites did burst at pressures of 57 and 62 mmHg, respectively. CONCLUSIONS: Endoscopic transmural suturing enables rapid and easy placement of leak-proof resorbable sutures and is suitable for closure of the NOTES transgastric access.

Submucosal cushioning with water jet before endoscopic mucosal resection : Which fluids are effective?

BACKGROUND: Several new techniques have recently been described that allow the endoscopic mucosal resection even of broad-based flat lesions in the gastrointestinal tract. The technique recently described by us of using a water jet dissector (Helix HydroJet) for a selective deposition of liquid in the submucosal lamina has now been combined with different substances, and their effects have been compared. MATERIAL AND METHODS: Gastroscopies were carried out in 8 pigs under intubation anesthesia, and 2 submucosal cushions each were created in the stomach using one out of 4 test substances (gelatin, glucose 50, hydroxyethyl starch [HES] 10%, dextran 40), as well as one cushion of isotonic saline solution placed in each area via the Helix HydroJet). The height of the submucosal cushions was intermittently measured over a period of 40 or 20 min, respectively, by miniprobe endosonography. In 7 of the animals the stomach was subsequently subjected to mucosal resection. The specimens and the gastric wall were histologically assessed to evaluate the localization of the liquid cushion and the effect on adjacent layers of the gastric wall. RESULTS: All test substances produced strictly selective liquid cushions in the submucosa. With HES 10% and dextran the maximum height of the cushions initially increased and then decreased during the further course to an average of 90% of the initial height within 40 min. Isotonic saline solution showed the most rapid decrease in height (72% after 20 min). The histological assessment confirmed the selective nature of the liquid deposit in the submucosa. DISCUSSION: Plasma expanders produced cushions that initially increased in height but then remained constant for a longer period than cushions produced using glucose 50, gelatin, or isotonic saline solution. The combination of transmucosal jet application for elevation of the mucosa with plasma expanders is therefore an interesting approach to optimize endoscopic mucosal resections.

Selective fluid cushion in the submucosal layer by water jet: advantage for endoscopic mucosal resection.

BACKGROUND/AIM: Numerous new techniques have recently been reported and described for the endoscopic mucosal resection of large superficial lesions of the gastrointestinal tract. We present here for the first time the application of a water jet dissector for mucosa elevation. MATERIALS AND METHODS: In an ex vivo study, the effectiveness of a water jet dissector (Helix Hydro-Jet) placed directly on the stomach walls of 8 pigs was examined to create a mucosal elevation. After having determined optimal pressures, angle of application, and application times, 13 submucosal fluid cushions were produced in different areas of the stomach walls of 8 pigs in vivo, and the sizes of the resulting submucosal cushions were measured. RESULTS: Using pressures between 30 and 70 bar, it was routinely possible to create submucosal fluid cushions in the stomach wall ex vivo as well as in vivo. Histological examination showed a selective edema in the submucosa without damage to the deeper mucosal layers of the gastric wall. CONCLUSIONS: The capacity of a targeted high-pressure water jet to penetrate the mucosa and selectively create a fluid cushion in the submucosa facilitates endoscopic resection of the mucosa. This new method could contribute to ameliorate the endoscopic treatment of mucosal tumors which previously could not be resected endoscopically due to their size, extent, or location.

A new technique of endoscopic full-thickness resection using a flexible stapler.

There is a significant need for a safe and easy technique for endoluminal endoscopic resection of gastrointestinal lesions, but such procedures are usually restricted to resection of the mucosal layer in order to preserve the integrity of the wall of the gastrointestinal tract. We present two patients, one with early cancer and one with a carcinoid tumor, who were treated by endoscopic full-thickness resection. We used a stapling device, consisting of a flexible shaft, which was positioned intraluminally, and a remote control. After pilot investigations in pigs and in human anatomical preparations, we performed a full-thickness resection of the gastric wall in these patients, using the flexible stapling device under gastroscopic control. Gastric wall specimens up to 4 cm x 4 cm in size were resected with the use of two to three stapler magazines. Both procedures followed an uneventful course and the patients made an uncomplicated recovery. Further studies are necessary to test the applicability of the technique in the management of other gastric neoplastic lesions.

Endoscopic full-thickness resection of the stomach: an experimental approach.

BACKGROUND: Endoluminal endoscopic resections of the gastrointestinal (GI) tract have had increasing significance in recent years. Except for the extraperitoneal part of the rectum, endoscopic resections are restricted to the mucosal and submucosal layer to preserve the integrity of the GI tract wall. METHODS: The SurgAssist is the first flexible stapling device consisting of a 2,000-mm-long flexible shaft and a stapling magazine that can be positioned intraluminally and used with a remote control. To prove the principle, we investigated the endoluminal application of an endoscopically assisted and intraluminally visualized full-thickness resection of the gastric wall in a pilot study of three pigs and a series of three human exenterates. RESULTS: Full-thickness resection of the gastric wall in pigs can be performed with the SurgAssist flexible stapling device from an endoluminal access. However, due to the small lumen of the esophagus, the simultaneous transesophageal introduction of the stapler shaft and gastroscope is not possible in pigs. The same procedure in three human exenterates showed that the simultaneous introduction of the flexible stapler and a standard gastroscope could be achieved without damaging the esophageal wall. Full-thickness resections of up to 4 x 4 cm were carried out with the use of two or three stapler magazines. The resulting sutures were found to be airtight upon endoscopic inflation of the stomach. CONCLUSION: The clinical use of the SurgAssist intraluminal stapling device for endoscopic full-thickness resection of the gastric wall seems applicable for lesions in suitable locations of the stomach. Gastrointestinal stroma tumors and T1 tumors of the lower gastric corpus and antrum region are possible indications.

[Localization of bleeding using 4-row detector-CT in patients with clinical signs of acute gastrointestinal hemorrhage]. / Blutungslokalisation mittels 4-Zeilen-Spiral-CT bei Patienten mit klinischen Zeichen einer akuten gastrointestinalen Hämorrhagie.

PURPOSE: There is no gold-standard regarding the diagnostic work-up and therapy of an acute gastrointestinal (GI) hemorrhage. In most cases endoscopy provides the diagnosis but in a low percentage this modality is not feasible or negative. Purpose of this study was to evaluate the role of multi-phase Multi-Slice-Computertomography (MSCT) as a modality to diagnose and locate the site of acute GI hemorrhage in case of unfeasible or technically difficult endoscopy. MATERIALS AND METHODS: 58 patients, presenting with clinical signs of lower GI hemorrhage, were examined through a 24-month period. Preliminary endoscopy was either negative or unfeasible. Images were obtained with a four-detector row CT with an arterial (4 x 1 mm collimation, 0.8 mm increment, 1.25 mm slice width, 120 kV, 165 mAs) and portal venous series (4 x 2,5 mm collimation, 2 mm increment, 3 mm slice width, 120 kV, 165 mAs). Time interval between endoscopy and CT varied between 30 minutes and 3 hours. The results of the MSCT were correlated with clinical course and surgical or endoscopical treatment. RESULTS: 20 of the 58 patients (34 %) undergoing MSCT had a bleeding site identified, thus providing decisive information for the following intervention. In case of a following therapeutic intervention there was 100 % correlation regarding the bleeding site. In 38 of the 58 patients (66 %), a bleeding site was not identified by MSCT. Twenty of these 38 patients (53 %) were stable and required no further treatment. In 18 of these 38 patients further interventional therapy was required due to continuing hemorrhage and in all of those patients the bleeding site was detected by intervention. CONCLUSION: Compared to other diagnostic methods MSCT is a fast, widely-available and low-risk technique for the localization of active GI hemorrhage. The clinical use seems to be justified since in more than one third of the patients, MSCT demonstrates the site of bleeding and provides decisive information for further interventional therapy. Concerning those patients, in whom MSCT is negative (38 out of 58 patients), only every second patient requires any additional diagnostic work-up.