Bariatric reduction system - BARS: device, technique and first clinical experience.

BACKGROUND: Roux-en-Y gastric by-pass (RYGB) is one of the most effective bariatric procedures, but the rate of weight regain (WR) can reach 63% after the second year. Enlargement of the gastrojejunal anastomosis is one of the reported causes. A newly CE-marked flexible endoscopic system, Bariatric Anastomotic Reduction System (BARS) (Ovesco Endoscopy, Tuebingen, Germany), derivative of the well-established endoscopic over-the-scope-clip (OTSC) clipping system, has been recently developed. It was tested in pre-clinical and preliminary clinical use for feasibility and effectiveness in bariatric anastomotic reduction. MATERIAL AND METHODS: Using a single-channel endoscope with external supplemental working channel, the BARS device captures the two limbs of the anastomosis, reducing its size, thus slowing food passage. After preclinical assessment, six patients with at least a 15% WR and the presence of an enlarged gastrojejunostomy > 20 mm were enrolled. The mean patient age was 49 years (range 24-67). Average interval between gastric bypass and BARS procedure: 8 years (4-13). RESULTS: All procedures were safely performed without complications. Mean procedure time: 52 min (37 - 75). Preliminary results: mean weight loss 6 kg (4-9) at a 3-month FU. CONCLUSIONS: BARS could be a promising endoscopic system in case of WR after gastric bypass due to enlargement of the anastomosis.

Preclinical evaluation of a novel thermally sensitive co-polymer (LiftUp) for endoscopic resection.

Introduction: Endoscopic resection techniques can successfully resect large lesions either in "en bloc" fashion or in "piece-meal" technique by using a submucosal injection solution. The aim of this study was to evaluate the safety of a novel injectable, containing thermally sensitive co-polymer from ethylenoxide and propylenoxide (LiftUp) used as submucosal injection solution.Material and methods: We conducted an in vivo animal trial in the porcine model to evaluate the LiftUp gel in a preclinical setting and to study the effectiveness of mucosal lifting and the safety of the new injectable. In seven animals a total of 63 injections and endoscopic resections were carried out in different anatomical locations (esophagus, stomach and rectum). The resection sites were controlled endoscopically one and four weeks after resection and a histopathological evaluation of the resection sites was performed after four weeks.Results: The application of LiftUp was safe and there were no negative effects on wound healing after injection and resection. A major procedural complication rate (defined as perforation and major haemorrhage) of 3.2% was registered, which undercuts the anticipated mean complication rate of 4-8%. Furthermore, there was no necessity of reinjection after the initial submucosal injection in 90.5% and no procedural complications in 98.8%. The histopathological examination of the tissue samples indicated normal wound healing with granulation tissue and epithelialisation.Conclusion: The use of LiftUp as submucosal injection solution was feasible for different endoscopic resection techniques, with high and long-lasting elevation and fewer procedural adverse events than expected at trial planning. The new injectable is a practical advancement over the current state-of-the-art of submucosal injection and could fasten up the resection procedure and make endoscopic 'en bloc' resection safer.

Laparoscopic gastro-jejunal anastomosis using novel r2 deflectable instruments in an ex vivo model.

OBJECTIVE: A novel 5 mm steerable instrument system (r2-DRIVE) was developed with active tip deflection and tip and shaft rotation. The feasibility and training effect of the r2 instruments were determined in a phantom model. MATERIAL AND METHODS: Experienced laparoscopic surgeons and untrained novices performed laparoscopic gastro-jejunal anastomoses using porcine tissue and r2 DRIVE-instruments. Mean anastomosis time, anastomosis width and burst pressure were measured. Number of stitches, skipped stitches and dropped needles were counted. Results of trained and untrained subjects were compared. RESULTS: Mean time for suturing decreased rapidly for all participants, but was more evident for untrained persons. After five anastomoses no relevant improvement in anastomotic time was seen for the skilled group. The ease of use, efficacy of manipulation and swift training effect with the novel r2 instruments for both experienced laparoscopic surgeons and untrained non-surgeons could be demonstrated and after few cases stable anastomosis times and a fast learning curve were obtained. CONCLUSIONS: This study demonstrates the ease of use, efficacy of manipulation and swift training effect with the novel r2 instruments for both experienced laparoscopic surgeons and untrained non-surgeons. After few cases stable anastomosis times and a fast learning curve were obtained.

A miniaturized robotic platform for natural orifice transluminal endoscopic surgery: in vivo validation.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) involves accessing the abdominal cavity via one of the body natural orifices for enabling minimally invasive surgical procedures. However, the constraints imposed by the access modality and the limited available technology make NOTES very challenging for surgeons. Tools redesign and introduction of novel surgical instruments are imperative in order to make NOTES operative in a real surgical scenario, reproducible and reliable. Robotic technology has major potential to overcome current limitations. METHODS: The robotic platform described here consists of a magnetic anchoring frame equipped with dedicated docking/undocking mechanisms to house up to three modular robots for surgical interventions. The magnetic anchoring frame guarantees the required stability for surgical tasks execution, whilst dedicated modular robots provide the platform with adequate vision, stability and manipulation capabilities. RESULTS: Platform potentialities were demonstrated in a porcine model. Assessment was organized into two consecutive experimental steps, with a hybrid testing modality. First, platform deployment, anchoring and assembly through transoral-transgastric access were demonstrated in order to assess protocol feasibility and guarantee the safe achievement of the following experimental session. Second, transabdominal deployment, anchoring, assembly and robotic module actuation were carried out. CONCLUSIONS: This study has demonstrated the feasibility of inserting an endoluminal robotic platform composed of an anchoring frame and modular robotic units into a porcine model through a natural orifice. Once inserted into the peritoneal cavity, the platform provides proper visualization from multiple orientations. For the first time, a platform with interchangeable modules has been deployed and its components have been connected, demonstrating in vivo the feasibility of intra-abdominal assembly. Furthermore, increased dexterity employing different robotic units will enhance future system capabilities.

Single-port live donor nephrectomy using a novel Curved Radius r2 Surgical System in an in vivo model.

OBJECTIVE: Single-port laparoscopic donor nephrectomy provides low morbidity and satisfactory cosmetic results for patients. The aim of this animal study was to establish a surgical technique of single-site (LESS) living donor nephrectomy using novel curved r2 CURVE manipulators specially designed for single-port access. MATERIAL AND METHODS: A total of six LESS nephrectomies were performed in three female pigs. r2 CURVE-instruments (Tuebingen Scientific Medical GmbH) were used providing a curved rotatable shaft, endless tip rotation, as well as 90° tip deflection. A 10 mm 30° extra long laparoscope, r2-curved Grasper, Maryland dissector and bipolar scissors were used for mobilization and dissection. RESULTS: All LESS nephrectomies were performed successfully. Average operative time was 80 min (range, 42-149 min). No technical problems were observed. Insertion and extraction of the instruments through the single-port were easy to conduct. The diameter of the used single-port was sufficient for safe manual organ harvesting. Potential conflict between the laparoscope and the instrument handles was avoided by using an extra long laparoscope. CONCLUSIONS: The new curved and deflectable instruments showed that single-port nephrectomy using the R2 manipulators is feasible. Single-port laparoscopic nephrectomy might be more patient-friendly and improve the willingness of potential donors to donate live organs.

Endoluminal full-thickness resection of GI lesions: a new device and technique.

Full-thickness resection techniques are of growing interest in the field of endoscopic removal of tumors or their precursors in the digestive tract. A new dedicated full-thickness resection device has been developed based on the combination of the OTSC clip, an enlarged resection cap and an integrated snare. The device prototype allows combined resection of all gastrointestinal organ wall layers in one maneuver, up to a size of 3 x 3 cm. The device has been pre-clinically tested to demonstrate feasibility of full-thickness resection in the colon. Two clinical cases have been performed successfully to date.

Over-the-scope clip closure of two chronic fistulas after gastric band penetration.

Gastrointestinal perforations are conservatively managed at endoscopy by through-the-scope endoclips and covered self expandable stents, according to the size and tissue features of the perforation. This is believed to be the first report of successful closure of two gastro-cutaneous fistulas with over-the-scope clips (OTSCs). After laparoscopic gastric banding, a 45-year old woman presented with band erosion and penetration. Despite surgical band removal and gastric wall suturing, external drainage of enteric material persisted for 2 wk, and esophagogastroduodenoscopy demonstrated two adjacent 10-mm and 15-mm fistulous orifices at the esophagogastric junction. After cauterization of the margins, the 10-mm fistulous tract was grasped by the OTSC anchor, invaginated into the applicator cap, and closed by a traumatic OTSC. The other 15-mm fistula was too large to be firmly grasped, and a fully-covered metal stent was temporarily placed. No leak occurred during the following 6 wk. At stent removal: the OTSC was completely embedded in hyperplastic overgrowth; the 15-mm fistula significantly reduced in diameter, and it was closed by another traumatic OTSC. After the procedure, no external fistula recurred and both OTSCs were lost spontaneously after 4 wk. The use of the anchor and the OTSC seem highly effective for successful closure of small chronic perforations.

Implantable endoscopic gastric bypass - device and experimental procedure.

Malabsorptive bariatric surgery is an effective treatment option for morbid obesity, but may be associated with complications and side effects. We have developed a new experimental approach to creating a gastric bypass through an intraluminal access. The goal is to reduce postoperative complications and to reduce mid-term side-effects of malabsorptive bypass food passage and to allow easy reversion of the procedure. The new procedure is based on an implantable gastric bypass device, installed by combined transoral flexible and minimally invasive abdominal access. The newly developed device and procedure were studied in a pilot experimental trial in the porcine animal model (n=8). Endpoints were the feasibility of the technical procedure, the ability of the animal to eat and digest food, the implant functionality over the survival period and the absence of major complications over a short-term follow-up (one week). The procedure was technically successful in all eight animals. Animals were able to take in food and water till sacrifice. Four animals had major complications (one abdominal wall dehiscence, one invagination ileus of the small bowel, one dehiscence of the gastro-jejunal anastomosis and one myocardial infarction) and did not complete follow-up. In two cases migration of the device into the stomach was observed. The difference between our experimental technique and the gold standard surgical methods for gastric bypass consists of the endoluminal approach by implanting an intraluminal gastric bypass device. This concept avoids gastric transsection and an additional anastomosis and enables an adjustable food passage between the bypass and the natural duodenal passage. Further long-term follow-up studies are required.

Propeller-based wireless device for active capsular endoscopy in the gastric district.

An innovative approach to active locomotion for capsular endoscopy in the gastric district is reported in this paper. Taking advantage of the ingestion of 500 ml of transparent liquid by the patient, an effective distension of the stomach is safely achieved for a timeframe of approximately 30 minutes. Given such a scenario, an active swallowable capsule able to navigate inside the stomach thanks to a four propeller system has been developed. The capsule is 15 mm in diameter and 30 mm in length, and it is composed of a supporting shell containing a wireless microcontroller, a battery and four motors. The motors enable the rotation of propellers located in the rear side of the device, thus obtaining a reliable locomotion and steering of the capsule in all directions in a liquid. The power consumption has been properly optimized in order to achieve an operative lifetime consistent with the time of the diagnostic inspection of the gastric district, assumed to be no more than 30 minutes. The capsule can be easily remotely controlled by the endoscopist using a joystick together with a purposely developed graphical user interface. The capsule design, prototyping, in vitro, ex vivo and preliminary in vivo tests are described in this work.

Feasibility study for secure closure of natural orifice transluminal endoscopic surgery gastrotomies by using over-the-scope clips.

BACKGROUND: The secure sealing of natural orifice transluminal endoscopic surgery (NOTES) approaches to the abdominal cavity is a problem that has not been solved. The feasibility of closing iatrogenic endoscopic GI-tract perforations by using a new over-the-scope clip was recently described. OBJECTIVE: To demonstrate the feasibility of endoscopic closure of transgastric NOTES approaches with a novel clip system. DESIGN: Acute nonsurvival animal study (porcine model; n = 9). INTERVENTIONS: Transgastric approaches were performed by using a needle-knife and balloon dilation. After abdominopelvic exploration, the transgastric approaches were closed by using the OTSC clipping system with suction. The procedure was performed under laparoscopic visualization. RESULTS: Gastrotomy lesions could primarily be closed in 8 cases. However, the laparoscopic control indicated that the clip adaptation of the wound margins was not completely airtight under maximum insufflation of the stomach in 4 of 9 cases. LIMITATION: Nonsurvival animal study. CONCLUSIONS: Sufficient closure of transgastric NOTES approaches is feasible when using the OTSC system. When considering our clinical experience, the OTSC system was shown to be an uncomplicated and secure sealing technique in human beings.

Feasibility proof of a legged locomotion capsule for the GI tract.

BACKGROUND: A colonoscopy and a gastroscopy are the most important screening measures for malignant diseases in the GI tract. One of the main limitations is the lack of patient adherence to come in for a flexible endoscopy, especially in asymptomatic conditions. OBJECTIVE: The feasibility proof of a new generation of endoscopic capsules based on a novel propelling mechanism that features electromechanical legs. DESIGN: Teleoperated endoscopic 8-legged capsule. SETTING: Scuola Superiore Sant'Anna, Pisa, Italy, and novineon Healthcare Technology Partners GmbH, Tübingen, Germany. MAIN OUTCOME MEASUREMENTS: Successful locomotion in a lower-GI tract (LGI) phantom model and in a porcine colon. RESULTS: The testing session was organized into repetitive ex vivo trials and in vivo tests. The repetitive tests were performed for collecting reproducible data in various small series of individual experiments in standardized conditions, thus defining the best locomotion parameters. In vivo tests were performed in a porcine colon: the capsule, inserted transanally, traveled upward in the oral direction for 15 cm in about 5 minutes, against peristalsis. LIMITATIONS: The current version of the capsule travels curves by bouncing back from the wall and following step by step the direction of the curved bowel. Steering mechanisms are not yet implemented. CONCLUSIONS: This study shows the systematic development and medical assessment of an imaging capsule with self-propelling abilities. A full colonic passage was successfully demonstrated in the ex vivo phantom model. A net movement in in vivo tests has been achieved, thus giving a feasibility proof of the legged locomotion as a possible solution to the problem of self-locomoting endoscopic devices in the LGI.

A new endoscopic over-the-scope clip system for treatment of lesions and bleeding in the GI tract: first clinical experiences.

BACKGROUND: We report on 11 patients with gastric or colonic bleeding or lesions who were treated with a new endoscopic over-the-scope clip (OTSC) system. OBJECTIVE: The aim of this retrospective analysis was the evaluation of the clinical outcome and description of the new endoscopic device. DESIGN: The data of the patients were evaluated retrospectively. SETTING: The OTSC system is composed of an application cap, which is mounted onto the distal tip of the endoscope and a connected releasing mechanism, installed on the handle of the scope. Two different variants of the clip, consisting of a shape-memory alloy (nitinol) are available: the "traumatic" and the "atraumatic" versions. In contrast to common endoscopic clips, the OTSC is able to compress larger quantities of tissue. PATIENTS: We treated 11 patients (range, 51-84 years; 8 men, 3 women) with severe bleeding or deep wall lesions, or perforations of the GI tract. RESULTS: All treatments were primarily successful, hemostasis was achieved, and lesions could be closed. We reexamined the patients after the intervention and did not see any complications that could be ascribed to the clip itself or to the applicator cap. CONCLUSIONS: The OTSC system is a new tool for the endoscopic compression of tissue. Indications for its use are difficult nonvaricose bleedings and lesions or perforations of the GI tract.

Wireless capsule endoscopy: from diagnostic devices to multipurpose robotic systems.

In the recent past, the introduction of miniaturised image sensors with low power consumption, based on complementary metal oxide semiconductor (CMOS) technology, has allowed the realisation of an ingestible wireless capsule for the visualisation of the small intestine mucosa. The device has received approval from Food and Drug Administration and has gained momentum since it has been more successful than traditional techniques in the diagnosis of small intestine disorders. In 2004 an esophagus specific capsule was launched, while a solution for colon is still under development. However, present solutions suffer from several limitations: they move passively by exploiting peristalsis, are not able to stop intentionally for a prolonged diagnosis, they receive power from an internal battery with short length, and their usage is restricted to one organ, either small bowel or esophagus. However the steady progresses in many branches of engineering, including microelectromechanical systems (MEMS), are envisaged to affect the performances of capsular endoscopy. The near future foreshadows capsules able to pass actively through the whole gastrointestinal tract, to retrieve views from all organs and to perform drug delivery and tissue sampling. In the long term, the advent of robotics could lead to autonomous medical platforms, equipped with the most advanced solutions in terms of MEMS for therapy and diagnosis of the digestive tract. In this review, we discuss the state of the art of wireless capsule endoscopy (WCE): after a description on the current status, we present the most promising solutions.

Comparative Study of the Use of a Suturing System and Titanium Clips.

There is a need for secure and easy methods for suturing in laparoscopic surgery, no matter whether vessels are to be ligated, two structures sutured together, or the cystic duct is to be occluded in cholecystectomy. Laparoscopic suturing can be done with a suture, using automatic sewing devices or clips. Improper ligation of a vessel for example can result in bleeding, which is more difficult to treat in a laparoscopic procedure than in an open procedure. By using a Roeder knot in laparoscopic suturing, tying of the knot requires some expertise and makes the procedure more complicated and time-consuming.