Antonello Forgione

The Mechanism of Diabetes Control After Gastrointestinal Bypass Surgery Reveals a Role of the Proximal Small Intestine in the Pathophysiology of Type 2 Diabetes

Summary Background Data:Most patients who undergo Roux-en-Y gastric bypass (RYGB) experience rapid resolution of type 2 diabetes. Prior studies indicate that this results from more than gastric restriction and weight loss, implicating the rearranged intestine as a primary mediator. It is unclear, however, if diabetes improves because of enhanced delivery of nutrients to the distal intestine and increased secretion of hindgut signals that improve glucose homeostasis, or because of altered signals from the excluded segment of proximal intestine. We sought to distinguish between these two mechanisms. Methods:Goto-Kakizaki (GK) type 2 diabetic rats underwent duodenal-jejunal bypass (DJB), a stomach-preserving RYGB that excludes the proximal intestine, or a gastrojejunostomy (GJ), which creates a shortcut for ingested nutrients without bypassing any intestine. Controls were pair-fed (PF) sham-operated and untreated GK rats. Rats that had undergone GJ were then reoperated to exclude the proximal intestine; and conversely, duodenal passage was restored in rats that had undergone DJB. Oral glucose tolerance (OGTT), food intake, body weight, and intestinal nutrient absorption were measured. Results:There were no differences in food intake, body weight, or nutrient absorption among surgical groups. DJB-treated rats had markedly better oral glucose tolerance compared with all control groups as shown by lower peak and area-under-the-curve glucose values (P < 0.001 for both). GJ did not affect glucose homeostasis, but exclusion of duodenal nutrient passage in reoperated GJ rats significantly improved glucose tolerance. Conversely, restoration of duodenal passage in DJB rats reestablished impaired glucose tolerance. Conclusions:This study shows that bypassing a short segment of proximal intestine directly ameliorates type 2 diabetes, independently of effects on food intake, body weight, malabsorption, or nutrient delivery to the hindgut. These findings suggest that a proximal intestinal bypass could be considered for diabetes treatment and that potentially undiscovered factors from the proximal bowel might contribute to the pathophysiology of type 2 diabetes.

Transvaginal endoscopic cholecystectomy in human beings: preliminary results.

INTRODUCTION The exciting concept of performing surgery in the peritoneal cavity without abdominal incisions by means of flexible endoscopes introduced through natural orifices-natural orifice transluminal endoscopic surgery (NOTES) has been widely investigated in recent years in experimental settings. However, experience with this procedure in human beings is still lacking. In this paper, we report the preliminary results of a small consecutive series of transvaginal endoscopic cholecystectomies. METHODS A standard double-channel gastroscope introduced into the abdominal cavity through a posterior colpotomy was used to perform the cholecystectomy. The introduction of a 5-mm trocar in the left-upper abdominal quadrant was mandatory to create and monitor the pneumoperitoneum and allow the application of the standard laparoscopic clips. This port was also used to introduce a grasper that assisted in the exposure of the gallbladder. The gallbladder was removed through the vagina and was protected in a plastic bag. RESULTS Since July 2007, 3 patients were successfully operated on by this approach, including 1 morbidly obese woman with a body mass index (BMI) of 45. The mean operative time was 136 minutes (range, 110-190). No postoperative complications occurred, and the patients did not complain of pain at both access sites. At the 1-month follow-up, none of the patients complained of dyspareunia. CONCLUSIONS The transvaginal cholecystectomy is feasible, safe, and reproducible in women within a wide range of BMI. NOTES might dramatically change the way surgery will be conceived and performed in the future, as it holds the potential to abolish the historic association of surgery with pain and scars.

IN VIVO STUDY OF FORCES DURING NEEDLE INSERTIONS

Percutaneous procedures are among the developing minimally invasive techniquesto treat cancerous diseases of the digestive system. They require a very accuratetargeting of the organs, achieved by the combination of tactile sensing and medicalimaging. In this paper, we study the forces involved during in vivo percutaneousprocedures for the development of a force feedback needle insertion robotic systemas well as the development of a realistic simulation device. The paper presentsdi erent conditions (manual and robotic insertions) and di erent organs (liver andkidney). Finally, we review some bio-mechanical models of the literature in thelight of our measurements.

Two-stage totally minimally invasive approach for acute complicated diverticulitis.

Objectives  Surgical options for acute diverticulitis with peritonitis include Hartmanns procedure or resection and primary anastomosis with or without a stoma. Initial laparoscopic lavage and drainage can control the acute intra‐abdominal sepsis to allow for a delayed definitive procedure in nonemergency conditions. Potential advantages include the avoidance of a laparotomy, stoma and local infections at the origin of dehiscence and incisional hernias. We evaluated this approach in a selected group of patients.

Towards robotized beating heart TECABG: Assessment of the heart dynamics using high-speed vision

Active robotic filtering is probably the solution for beating heart Totally Endoscopic Coronary Artery Bypass Grafting (TECABG). In this work, we assess the heart motion dynamics by simultaneous use of high-speed imaging of optical markers attached to the heart, ECG signals and ventilator airflow acquisitions. Our goal is to assess the heart motions (shape, velocity, acceleration) in order to be able to make more accurate specifications for a novel, dedicated robot that could follow these motions in real time. Furthermore, using two additional inputs (ECG and airflow), we propose a novel robust prediction algorithm that could be used with a predictive control algorithm to improve the tracking accuracy.

European association of endoscopic surgeons (EAES) consensus statement on the use of robotics in general surgery

Following an extensive literature search and a consensus conference with subject matter experts the following conclusions can be drawn: 1. Robotic surgery is still at its infancy, and there is a great potential in sophisticated electromechanical systems to perform complex surgical tasks when these systems evolve. 2. To date, in the vast majority of clinical settings, there is little or no advantage in using robotic systems in general surgery in terms of clinical outcome. Dedicated parameters should be addressed, and high quality research should focus on quality of care instead of routine parameters, where a clear advantage is not to be expected. 3. Preliminary data demonstrates that robotic system have a clinical benefit in performing complex procedures in confined spaces, especially in those that are located in unfavorable anatomical locations. 4. There is a severe lack of high quality data on robotic surgery, and there is a great need for rigorously controlled, unbiased clinical trials. These trials should be urged to address the cost-effectiveness issues as well. 5. Specific areas of research should include complex hepatobiliary surgery, surgery for gastric and esophageal cancer, revisional surgery in bariatric and upper GI surgery, surgery for large adrenal masses, and rectal surgery. All these fields show some potential for a true benefit of using current robotic systems. 6. Robotic surgery requires a specific set of skills, and needs to be trained using a dedicated, structured training program that addresses the specific knowledge, safety issues and skills essential to perform this type of surgery safely and with good outcomes. It is the responsibility of the corresponding professional organizations, not the industry, to define the training and credentialing of robotic basic skills and specific procedures. 7. Due to the special economic environment in which robotic surgery is currently employed special care should be taken in the decision making process when deciding on the purchase, use and training of robotic systems in general surgery. 8. Professional organizations in the sub-specialties of general surgery should review these statements and issue detailed, specialty-specific guidelines on the use of specific robotic surgery procedures in addition to outlining the advanced robotic surgery training required to safely perform such procedures.

Motion Prediction for Computer-Assisted Beating Heart Surgery

Off-pump totally endoscopic coronary artery bypass grafting is a milestone for cardiac surgery, and still a technical challenge. Indeed, the fast and complex cardiac motion makes this operating method technically demanding. Therefore, several robotic systems have been designed to assist the surgeons by compensating for the cardiac motion and providing a virtually motionless operating area. In the proposed systems, the servoing schemes often take advantage of a prediction algorithm that supplies the controller with some future heart motion. This prediction enlarges the control-loop bandwidth, thus allowing a better motion compensation. Obviously, improving the prediction accuracy will lead to better motion-compensation results. Thus, a current challenge in computer-assisted cardiac surgery research is the design of efficient heart-motion-prediction algorithms. In this paper, a detailed survey of the main existing prediction approaches is given and a classification is provided. Then, a novel prediction technique based on amplitude modulation is proposed, and compared with other techniques using in vivo collected datasets. A final discussion summarizes the main features of all the proposed approaches.

Cardiolock: An active cardiac stabilizer. First in vivo experiments using a new robotized device

Off-pump Coronary Artery Bypass Grafting (CABG) is still a technically difficult procedure. The mechanical stabilizers used for local suppression of the heart excursion have been demonstrated to exhibit significant residual motion, which could lead to a lack of accuracy in performing the surgical task, particularly when using a minimally invasive surgery (MIS) approach. We therefore propose a novel active stabilizer to compensate for the residual motion whose architecture is compatible with MIS. An experimental evaluation of a commercially available totally endoscopic stabilizer is first presented to demonstrate the unsatisfactory behavior of this device. Then, the interaction between the heart and a mechanical stabilizer is assessed in vivo using an animal model. Finally, the principle of active stabilization, based on the high-speed vision-based control of a piezo-actuated compliant mechanism, is presented, along with in vivo experimental results obtained using a prototype to demonstrate its efficiency.

Toward robotized beating heart TECABG: assessment of the heart dynamics using high-speed vision

Active robotic filtering is a promising solution for beating heart Totally Endoscopic Coronary Artery Bypass Grafting (TECABG). n this work, we assess the heart motion dynamics using simultaneously igh speed imaging of optical markers attached to the heart, ECG signals and ventilator airflow acquisitions. Our goal is to make an assessment of the heart motion (shape, velocity, acceleration) in order to be able to make more accurate specifications for a dedicated robot that could follow this motion in real-time. Furthermore, using the 2 additional inputs (ECG, airflow), we propose a prediction algorithm of the motion that could be used with a predictive control algorithm to improve the tracking accuracy.

Active Stabilization for Robotized Beating Heart Surgery

In this paper, control strategies for an active stabilizer dedicated to beating heart coronary artery bypass grafting are investigated. The active stabilizer, which consists of a piezoactuated compliant mechanism, has to be controlled to compensate for the displacements induced by the beating heart in order to provide the surgeon with a locally motionless myocardium surface. Three controllers, including different levels of prior knowledge about the heart motion, are presented. Their performance with respect to modeling uncertainties, arising unknown interactions of the stabilizer with its positioning mechanism, and the heart, is studied through simulations, as well as laboratory and in vivo experiments. Finally, the selection of the most adequate control scheme and the performance of the device from a clinical point of view are discussed.