Natural orifice cholecystectomy using a miniature robot

Background  Natural orifice translumenal endoscopic surgery (NOTES) is surgically challenging. Current endoscopic tools provide an insufficient platform for visualization and manipulation of the surgical target. This study demonstrates the feasibility of using a miniature in vivo robot to enhance visualization and provide off-axis dexterous manipulation capabilities for NOTES. Methods  The authors developed a dexterous, miniature robot with six degrees of freedom capable of applying significant force throughout its workspace. The robot, introduced through the esophagus, completely enters the peritoneal cavity through a transgastric insertion. The robot design consists of a central “body” and two “arms” fitted respectively with cautery and forceps end-effectors. The arms of the robot unfold, allowing the robot to flex freely for entry through the esophagus. Once in the peritoneal cavity, the arms refold, and the robot is attached to the abdominal wall using the interaction of magnets housed in the robot body with magnets in an external magnetic handle. Video feedback from the on-board cameras is provided to the surgeon throughout a procedure. Results  The efficacy of this robot was demonstrated in three nonsurvivable procedures in a porcine model, namely, abdominal exploration, bowel manipulation, and cholecystectomy. After insertion, the robot was attached to the interior abdominal wall. The robot was repositioned throughout the procedure to provide optimal orientations for visualization and tissue manipulation. The surgeon remotely controlled the actuation of the robot using an external console to assist in the procedures. Conclusion  This study has shown that a dexterous miniature in vivo robot can apply significant forces in arbitrary directions and improve visualization to overcome many of the limitations of current endoscopic tools for performing NOTES procedures. Presented at the 2008 Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Meeting, Philadelphia, Pennsylvania, April 9–12, 2008.     

Dexterous miniature robot for advanced minimally invasive surgery

This study demonstrates the feasibility of using a miniature robot to perform complex, single-incision, minimal access surgery. Instrument positioning and lack of triangulation complicate single-incision laparoscopic surgery, and open surgical procedures are highly invasive. Using minimally invasive techniques with miniature robotic platforms potentially offers significant clinical benefits. A miniature robot platform has been designed to perform advanced laparoscopic surgery with speed, dexterity, and tissue-handling capabilities comparable to standard laparoscopic instruments working through trocars. The robotic platform includes a dexterous in vivo robot and a remote surgeon interface console. For this study, a standard laparoscope was mounted to the robot to provide vision and lighting capabilities. In addition, multiple robots could be inserted through a single incision rather than the traditional use of four or five different ports. These additional robots could provide capabilities such as tissue retraction and supplementary visualization or lighting. The efficacy of this robot has been demonstrated in a nonsurvival cholecystectomy in a porcine model. The procedure was performed through a single large transabdominal incision, with supplementary retraction being provided by standard laparoscopic tools. This study demonstrates the feasibility of using a dexterous robot platform for performing single-incision, advanced laparoscopic surgery.     

In vivo miniature robots for natural orifice surgery: State of the art and future perspectives

Natural orifice translumenal endoscopic surgery (NOTES) is the integration of laparoscopic minimally invasive surgery techniques with endoscopic technology. Despite the advances in NOTES technology, the approach presents several unique instrumentation and technique-specific challenges. Current flexible endoscopy platforms for NOTES have several drawbacks including limited stability, triangulation and dexterity, and lack of adequate visualization, suggesting the need for new and improved instrumentation for this approach. Much of the current focus is on the development of flexible endoscopy platforms that incorporate robotic technology. An alternative approach to access the abdominal viscera for either a laparoscopic or NOTES procedure is the use of small robotic devices that can be implanted in an intracorporeal manner. Multiple, independent, miniature robots can be simultaneously inserted into the abdominal cavity to provide a robotic platform for NOTES surgery. The capabilities of the robots include imaging, retraction, tissue and organ manipulation, and precise maneuverability in the abdominal cavity. Such a platform affords several advantages including enhanced visualization, better surgical dexterity and improved triangulation for NOTES. This review discusses the current status and future perspectives of this novel miniature robotics platform for the NOTES approach. Although these technologies are still in pre-clinical development, a miniature robotics platform provides a unique method for addressing the limitations of minimally invasive surgery, and NOTES in particular.     

A reliable method for monitoring intraabdominal pressure during natural orifice translumenal endoscopic surgery

Background Natural orifice translumenal endoscopic surgery (NOTES) provides surgical access to the peritoneal cavity without skin incisions. The NOTES procedure requires pneumoperitoneum for visualization and manipulation of abdominal organs, similar to laparoscopy. Accurate measurement of the pneumoperitoneum pressure is essential to avoid potentially deleterious effects of intraabdominal compartment syndrome. A reliable method for monitoring pneumoperitoneum pressures during NOTES has not been identified. This study evaluated several methods of monitoring intraabdominal pressures with a standard gastroscope during NOTES. Methods Four female pigs (25 kg) were sedated, and a single-channel gastroscope was passed transgastrically into the peritoneal cavity. Pneumoperitoneum was achieved via a pressure insufflator through a percutaneous, intraperitoneal 14-gauge catheter. Three other pressures were recorded via separate catheters. First, a 14-gauge percutaneous catheter passed intraperitoneally measured true intraabdominal pressure. Second, a 14-gauge tube attached to the endoscope was used to measure endoscope tip pressure. The third pressure transducer was connected directly to the accessory channel of the endoscope. The abdomen was insufflated to a range of pressures (10–30 mmHg), and simultaneous pressures were recorded from all three pressure sensors. Results Pressure correlation curves were developed for all animals across all intraperitoneal pressures (mean error, –4.25 to –1 mmHg). Endoscope tip pressures correlated with biopsy channel pressures (R ² = 0.99). Biopsy channel and endoscope tip pressures fit a least-squares linear model to predict actual intraabdominal pressure (R = 0.99 for both). Both scope tip and biopsy channel port pressures were strongly correlative with true intraabdominal pressures (R ² = 0.98 and R ² = 0.99, respectively). Conclusion This study demonstrates that monitoring pressure through an endoscope is reliable and predictive of true intraabdominal pressure. Gastroscope pressure monitoring is a useful adjunct to NOTES. Future NOTES procedures should incorporate continuous intraabdominal pressure monitoring to avoid the potentially deleterious effects of pneumoperitoneum during NOTES. This can be achieved by the integration of pressure-monitoring capabilities into gastroscopes. Presented at the 2006 Scientific Session of Society of American Gastrointestional and Endoscopic Surgeons (SAGES), April 2006, Dallas, TX, USA     

Pure natural orifice transluminal endoscopic surgery (NOTES) nephrectomy using standard laparoscopic instruments in the porcine model

PURPOSE: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is an emerging technology that uses endoscopic instruments passed into the peritoneal cavity through hollow viscera to perform surgical procedures without the use of abdominal incisions. There are, however, limitations regarding the equipment available to simulate traditional surgery. The aim of this study was to determine the feasibility of a pure NOTES nephrectomy by using standard laparoscopic instruments through a modified transvaginal trocar. MATERIALS AND METHODS: One 40-kg female swine underwent transgastric peritoneoscopy. Transgastric endoscopic visualization guided the introduction of a second transvaginal endoscope through a novel laparoscopic trocar/endoscopic overtube device. The retroflexed transgastric endoscope provided triangulated visualization as standard endoscopic instruments provided retraction, which allowed dissection of the kidney with standard laparoscopic instruments through our modified transvaginal trocar device. Each renal hilum, artery, vein, and ureter was dissected and divided with a transvaginal laparoscopic stapler. RESULTS: Transgastric and transvaginal NOTES accesses were easily achieved, and bilateral nephrectomies were performed. Completion of peritoneoscopy revealed complete hemostasis and identification of ligated ureters and hilar vessels. Total operative time was 40 and 20 minutes for the right and left kidney, respectively. One kidney was captured with a laparoscopic retrieval sac and removed intact through the vaginal defect. CONCLUSIONS: Pure NOTES nephrectomies are technically feasible in the porcine model by using standard laparoscopic instruments. Survival studies are necessary to determine the long-term complications and physiologic implications of NOTES nephrectomy. The development of innovative NOTES access trocars may allow for an increased armamentarium of NOTES instruments.     

Transvaginal endoscopic partial gastrectomy in porcine models: the role of an extra endoscope for gastric control

Background  Transvaginal natural orifice translumenal endoscopic surgery (NOTES) gastrectomy is technically challenging, because wide perigastric dissection under appropriate tissue triangulation is unfeasible with current endoscopic instruments alone. The aim of this study was to investigate the feasibility of transvaginal NOTES gastrectomy with the use of an extra endoscope as a retracting device of the stomach. Methods  This acute in vivo feasibility study was performed under the approval of the Institutional Animal Care and Use Committee (IACUC). Four female 40-kg pigs received general anesthesia and underwent transvaginal endoscopic partial gastrectomy. Under laparoscopic guidance, the uterus was fixed anteriorly and transvaginal access was established in a standard fashion. The perigastric ligaments were dissected with needle knife/insulation-tipped electrosurgical knife (IT) via transvaginally placed double-channel endoscope. This step was assisted with the second, CO₂-insufflating endoscope advanced in the stomach (i.e., so-called endoscopic gastric control). A linear stapling device with a flexible shaft was then passed transvaginally, and the anterior gastric wall was partially resected. The specimen was isolated and retrieved through the vagina. Concluding endoscopy was carried out to confirm the absence of mucosal damage due to endoscopic gastric control. This was further confirmed at necropsy immediately after sacrifice. Results  All animals underwent successful transvaginal NOTES gastrectomy. Endoscopic gastric control greatly facilitated perigastric dissection by providing appropriate tissue countertraction on the ligaments. Use of transabdominal (laparoscopic) graspers was thus minimized. There were no intraoperative complications directly related to use of the primary (transvaginal) endoscope or the additional (gastric) endoscope. Distention of downstream bowel after gastric insufflation was minimal with CO₂. No major injuries were noted on gastric mucosa at postmortem investigations. Conclusions  Transvaginal NOTES partial gastrectomy is feasible in porcine models. Use of an extra endoscope to retract the stomach is effective to minimize transabdominal assistance. Further studies on human subjects are necessary to establish this as a safe and attractive ancillary technique in NOTES.     

Adrenalectomy using natural orifice translumenal endoscopic surgery (NOTES): A transvaginal retroperitoneal approach

Background  Endoscopic adrenalectomy currently is performed using either a retroperitoneal or transperitoneal approach. The retroperitoneal approach is ideal for patients with small lesions who have undergone previous intraabdominal surgery. This study aimed to explore transvaginal retroperitoneal right and left adrenalectomies in porcine and cadaver models. Methods  Right and left adrenalectomies were performed for two female pigs. With the pig supine under general anaesthesia, the retroperitoneal space was entered with a double-channel endoscope (Storz) through a posterior colpotomy. A retroperitoneal tunnel was fashioned using blunt dissection with the assistance of low carbon dioxide insufflation up to the inferior pole of the kidney. Dissection of the upper renal pole allowed access to the adrenal gland. Using blunt dissection, a plane was created between the aorta on the left and the adrenal gland and inferior vena cava on the right. The left main middle vascular pedicle was identified and taken between clips, whereas an endoloop was used on the right side. The specimen was retrieved intact with a polypectomy snare. The same access then was reproduced with two female cadavers. Results  Transvaginal retroperitoneal adrenalectomies were successfully accomplished with a transvaginal approach using natural orifice translumenal endoscopic surgery (NOTES). The operative time was 70 min, and there was no injury to the retroperitoneal structures. The access was effectively reproduced in the cadaver model, with prompt identification of the retroperitoneal anatomic landmarks. Conclusion  Transvaginal retroperitoneal NOTES adrenalectomy is feasible in the porcine model. It reaches the adrenal proper anatomic plane with no need for dissection or retraction of the surrounding organs. This technique might be especially valuable for patients with multiple previous abdominal operations and obese patients in that allows direct access to the adrenal gland and minimizes the cardiovascular and pulmonary risk related to carbon dioxide pneumoperitoneum. Although the operation was successfully validated with cadavers, further experiments and better tools are needed before NOTES transvaginal retroperitoneal access is considered for humans. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

NOTES: cadaveric rendezvous hybrid small bowel resection

Background  Natural orifice translumenal endoscopic surgery (NOTES) is an emerging field in minimally invasive surgery that is driving the development of new technology and techniques [1–4]. Before NOTES gains widespread popularity, it must be proven to be a safe and efficacious technique [5]. There are several proposed benefits to the NOTES approach, including potentially decreased abdominal pain, wound infections, and hernia formation. Methods  Currently, most investigational NOTES procedures are performed using a single transgastric, transcolonic, or transvaginal access point to the abdomen. In order to provide greater range of motion and freedom of movement, a rendezvous procedure using simultaneous transgastric and transcolonic approaches was used to perform a small bowel resection. This video demonstrates a successful NOTES hybrid small bowel resection with the use of two laparoscopic ports in a cadaveric model. A powered stapling device attached to a flexible shaft is introduced transcolonically and facilitates division and re-anastamosis of the small bowel. A dual-channel operating endoscope introduced transgastrically allows for precise dissection and creation of enterotomies necessary for the small bowel resection. Conclusions  While technically challenging, NOTES hybrid small bowel resection can be accomplished with specially designed instrumentation utilizing the rendezvous technique. There are several technical limitations preventing this procedure from being completed in a pure NOTES fashion. A safe method of creating blind enterotomies will be needed to eliminate laparoscopic visualization of the enterotomy sites. Adequate endoscopic exposure and retraction of tissue is still difficult and currently requires percutaneous adjuncts. New closure devices will be needed for safe and reliable NOTES enterotomy closure. With the development of such instruments, this, as well as other NOTES procedures, will become more technically feasible. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Tool guidance using a compact robotic assistant

Surgical robots in popular clinical use are generally large machines, which limits their practical use to some extent. This study aims to investigate the potential of a small, table-mounted robot for tool guidance in minimally invasive surgery (MIS). In particular, its multipurpose use for guidance of various tools was investigated. A compact robot capable of manipulating MIS tools was designed and built. The robot can move in four degrees of freedom (DOF): three rotational and one translational. These DOF correspond to motion constrained by a trocar. The robot kinematics are based on a bevel-geared “spherical mechanism,” which allows trocar-constrained motion using a small mechanical device. The robot was tested in a porcine model by manipulating scopes and robotic grasping tools using a joystick as directed by a surgeon. Holding a laparoscope, the robot provided superior stability as a camera assistant. It manipulated the scope for visualization of the liver, spleen, bowel, etc. during manual tissue manipulation. Its compactness allowed increased space around the operating table, and the robot was in fact manipulated by joystick from across the room. Maneuvering grasping tools, the robot similarly provided a stable and dexterous platform for tissue manipulation. The test results suggest that the use of robotics for surgery may be enhanced via compact devices to include more hybrid robotic–manual procedures. The robot motion is smoother and more repeatable than that of a human operator. Use of a foot joystick could also place camera control directly with the surgeon. Flexible endoscopes can also be used with the robot for highly dexterous visualization. Notably, changing tools with this system is a very straightforward process and can be achieved without re-registration of the robot’s position/orientation. Therefore, combined with other simple robotic tools for grasping, cautery, etc., compact robotic systems based on this technology could replace the large systems in current use, potentially increasing the impact of robots on medical care. This represents an important step towards multifunctional compact surgical robots.     

Cholecystectomy by a combined transgastric and transparietal approach using two flexible endoscopes

Objective  This experimental study was designed to assess the technical feasibility and benefits of our novel approach for transgastric NOTES (natural orifice translumenal endoscopic surgery) cholecystectomy. Methods  Four pigs were subjected to NOTES cholecystectomy by the combined transgastric and transparietal approach using two flexible endoscopes. Under the guidance of a transparietal endoscope inserted through a trocar placed in the right upper abdomen, a gastrotomy was constructed, and a peroral endoscope was advanced into the peritoneal cavity through the gastrotomy and moved on retroflexion toward the gallbladder. Gallbladder excision with ligation of the cystic artery and duct using endoclips was performed using the peroral endoscope. After gastrotomy closure with endoclips inside the stomach, intraperitoneal lavage were carried out using the transparietal endoscope. Results  A complete gallbladder excision was carried out without major adverse events in all cases. The gastrotomies were successfully closed using endoclips (n = 3) or by the omentum-plug method (n = 1). Conclusion  This approach is technically feasible and makes transgastric NOTES cholecystectomy easier and safer.     

NOTES: issues and technical details with introduction of NOTES into a small general surgery residency program.

BACKGROUND AND OBJECTIVES: Natural orifice translumenal endoscopic surgery (NOTES) is a development of recent origin. In 2004, Kalloo et al first described NOTES investigation in an animal model. Since then, several investigators have pursued NOTES study in animal survival and nonsurvival models. Our objectives for this project included studying NOTES intervention in a laboratory environment using large animal (swine) models and learning to do so in a safe, controlled manner. Ultimately, we intend to introduce NOTES methodology into our surgical residency training program. The expertise of an experienced laparoscopic surgeon, fellowship-trained laparoendoscopic surgeon, and veterinarian along with a senior surgical resident was utilized to bring the input of several disciplines to this study. The Institutional Animal Care and Use Committee (IACUC) of Northeastern Ohio Universities College of Medicine and Pharmacy (NEOUCOM/COP) approved this study. METHODS: A series of 5 laboratory sessions using mixed breed farm swine varying in weight from 37 kg to 43.1 kg was planned for the initial phase of NOTES introduction into our residency program. Animals were not kept alive in this investigation. All animals were anesthetized using a standard swine protocol and euthanized following guidelines issued by the American Veterinary Medical Association Panel on Euthanasia. Equipment included a Fujinon EVE endoscope 0.8 cm in diameter with a suction/irrigation channel and one working channel. Initially, a US Endoscopy gastric overtube, 19.5 mm OD and 50 cm in length, was used to facilitate passage of the endoscope. However, this device was found to have insufficient length. Subsequently, commercially available 5/8" diameter clear plastic tubing, 70 cm to 80 cm in length, was adapted for use as an overtube. Standard endoscopic instruments included Boston Scientific biopsy forceps, needle-knife, papillotome, endoscopic clip applier, and Valley Lab electrosurgical unit. A Karl Storz laparoscope and tower were used for laparoscopic observation of NOTES maneuvers. Necropsy was performed to determine specific details of surgical intervention. RESULTS: NOTES intervention is feasible in an animal model. Insight into the potential of NOTES was obtained in this investigation. CONCLUSIONS: NOTES investigation in a controlled, laboratory setting using an animal model proved to have value for our program. A steep learning curve was encountered despite the availability of an investigator familiar with elementary NOTES procedures. The authors strongly suggest investigators adopt the ASGE/SAGES working group recommendations for a multidisciplinary team possessing advanced therapeutic endoscopic and advanced laparoscopic skills to study NOTES before human investigation. Animal laboratory facilities to perform research and training should be available to the multidisciplinary team for exploration of NOTES techniques and procedures. Institutional Review Board (IRB) approval must be obtained before introduction of NOTES procedures in human patients.     

NOTES transanal rectal cancer resection using transanal endoscopic microsurgery and laparoscopic assistance

Background  

The feasibility and safety of Natural Orifice Translumenal Endoscopic Surgery (NOTES) transanal endoscopic rectosigmoid resection using transanal endoscopic microsurgery (TEM) was previously demonstrated in human cadavers and a porcine survival model. We report the first clinical case of a NOTES transanal resection for rectal cancer using TEM and laparoscopic assistance, performed by a team of surgeons from Barcelona and Boston with extensive experience with NOTES and minimally invasive approaches to colorectal diseases.     

Current experience and future directions of completely NOTES colorectal resection

Clinical implementation and widespread application of natural orifice translumenal surgery (NOTES) has been limited by the lack of specialized endoscopic equipment, which has prevented the ability to perform complex procedures including colorectal resections. Relative to other types of translumenal access, transanal NOTES using transanal endoscopic microsurgery (TEM) provides a stable platform for endolumenal and direct translumenal access to the peritoneal cavity, and specifically to the colon and rectum. Completely NOTES transanal rectosigmoid resection using TEM, with or without transgastric endoscopic assistance, was demonstrated to be feasible and safe in a swine survival model. The same technique was successfully replicated in human cadavers using commercially available TEM, with endoscopic and laparoscopic instrumentation. This approach also permitted complete rectal mobilization with total mesorectal excision to be performed completely transanally. As in the swine model, transgastric and/or transanal endoscopic assistance extended the length of proximal colon mobilized and overcame some of the difficulties with TEM dissection including limited endoscopic visualization and maladapted instrumentation. This extensive laboratory experience with NOTES transanal rectosigmoid resection served as the basis for the first human NOTES transanal rectal cancer excision using TEM and laparoscopic assistance. Based on this early clinical experience, NOTES transanal approach using TEM holds significant promise as a safe and substantially less morbid alternative to conventional colorectal resection in the management of benign and malignant colorectal diseases. Careful patient selection and substantial improvement in NOTES instrumentation are critical to optimize this approach prior to widespread clinical application, and may ultimately permit completely NOTES transanal colorectal resection.     

NOTES: approach to the liver and spleen

Background  Minimally invasive abdominal surgery means minimal trauma to the abdominal wall, thus reducing postoperative pain and wound complications, and facilitating earlier mobilization and shorter hospitalization in comparison with conventional surgery. Natural orifice translumenal endoscopic surgery (NOTES) has the potential to further reduce the invasiveness of surgery in human patients. Here we report an experimental study of NOTES to access the liver and spleen, discuss its current status, and review the related literature. Methods  The utility of transgastric peritoneoscopy was evaluated using one 15-kg pig and four 8-kg dogs on the basis of acute experiments. Under general anesthesia with endotracheal intubation, a forward-viewing, double-channel endoscope was advanced into the peritoneal cavity through a gastric hole. Liver biopsy from the edge of the liver was performed using routine biopsy forceps. Splenectomy was performed using a laparoscopically assisted procedure, and then the spleen was pulled into the stomach using an endoscopic polypectomy snare after enlargement of the gastric orifice. The animals were then sacrificed and necropsy was performed. Results  There were no complications during incision of the gastric wall and entry into the peritoneal cavity. Peritoneoscopy gave satisfactory visualization of the abdominal cavity in all directions. Liver biopsy was performed successfully without any bleeding and adequate samples were obtained in all cases. Splenectomies were also accomplished uneventfully, except for injury of the splenic parenchyma due to excessive force during pulling into the stomach. Necropsy revealed no particular damage to other intraperitoneal organs related to this transgastric procedure. Conclusion  Although NOTES is a feasible procedure and offers several advantages to patients, surgeons and endoscopists need to resolve several key issues before its clinical introduction for routine surgical work and to establish a training system for NOTES in order to avoid critical complications.     

Forward kinematic analysis of in-vivo robot for stomach biopsy

The introduction of robotic medical assistance in biopsy and stomach cavity exploration is one of the most important milestones in the field of medical science. The research is still in its infancy and many issues like limitations in dexterity, control, and abdominal cavity vision are the main concerns of many researchers around the globe. This paper presents the design aspects and the kinematic analysis of a 4 degrees of freedom (DOF) hyper-redundant in-vivo robot for stomach biopsy. The proposed robot will be inserted through the tool channel of a conventional 4-DOF endoscope and this will increase the dexterity and ease in reaching the furthest parts of the stomach beyond the duodenum. Unlike the traditional biopsy tool, the present design will enhance dexterity due to its 4 DOF in addition to the endoscope’s DOF. The endoscope will be positioned at the entrance to the stomach in the esophagus and the robot will move to the desired position inside the stomach for biopsy and exploration. The current robot is wire-actuated and possesses better maneuverability. The forward kinematic analysis of the proposed robot is presented in this paper.     

Transvaginal laparoscopic cholecystectomy: laparoscopically assisted

Natural orifice transluminal endoscopic surgery (NOTES) is considered the new frontier for minimally invasive surgery. NOTES procedures such as peritoneoscopy, splenectomy, and cholecystectomy in animal models have been described. The aim of our experiment was to determine the feasibility and technical aspects of a new endoluminal surgical procedure. After approval from Columbia’s IACUC, a transvaginal laparoscopically assisted endoscopic cholecystectomy was performed on four 30 kg Yorkshire pigs. The first step was to insert a 1.5 cm endoscope into the vagina under direct laparoscopic vision. Then the gallbladder was reached and, with the help of a laparoscopic grasper to hold up the gallbladder, the operation was performed. At the end of the procedure the gallbladder was snared out through the vagina attached to the endoscope. There were no intraoperative complications such as bleeding, common bile duct or endo-abdominal organ damage. Total operative time ranged between 110 and 155 min. Based on our experience in the porcine model, we believe that a transvaginal endoscopic cholecystectomy is feasible in humans. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Evaluation for transvaginal and transgastric NOTES cholecystectomy in human and animal natural orifice translumenal endoscopic surgery

Background/purpose  Natural orifice translumenal endoscopic surgery (NOTES) is a novel concept using an endoscope via a translumenal access for abdominal surgery. This study was designed to evaluate the feasibility and technical aspects of NOTES cholecystectomy from our experience on humans and animals. Methods  NOTES cholecystectomies were performed in 12 animal experiments, including 8 pigs (6 by transgastric and 2 by transvaginal accesses) and 4 dogs (4 transvaginal accesses), and a human female cadaver. Results  The entire gallbladder could be removed under direct vision in all experiments. The average time was 60 min by transgastric and 40 min by transvaginal in animals. It was 87 min for human transvaginal cholecystectomy. In all animal and human procedures, there was no major complication concerning the operation. Discussion  The transvaginal route may be the easiest route for abdominal NOTES. Percutaneous endoscopic gastrostomy (PEG) allowed the safe performance of a controlled gastric perforation and shortened the time. The hybrid method allowed performance of a safe procedure and shortened the time. Conclusions  Transvaginal and transgastric NOTES cholecystectomy is technically feasible and safe in both humans and animals. New instrumentation needs to be developed to perform a pure NOTES cholecystectomy without transabdominal assistance.     

The current state of miniature in vivo laparoscopic robotics

Minimally invasive surgery (MIS) reduces patient trauma and shortens recovery time, but also limits the dexterity of the surgeon because degrees of freedom are lost due to the fulcrum effect of the entry incisions. Visual feedback is also limited by the laparoscope, which typically provides two-dimensional feedback and is constrained by the entry incision. Developments within surgical robotics aim to mitigate these constraints. However, these developments have primarily included large external machines that augment vision and improve dexterity, but are still fundamentally constrained by the use of long tools through small incisions. An alternative concept is the use of miniature in vivo surgical robots that can be placed entirely into the peritoneal cavity through either an abdominal incision, or, after insertion into the stomach through the esophagus, can enter through a gastrotomy. This paper reviews the development of fixed-base camera robots for providing auxiliary views of the surgical field and of mobile robots with a movable platform for vision and task assistance in laparoscopic procedures. Moreover, the progress towards the application of similar robots for natural orifice transluminal endoscopic surgery (NOTES) and forward environments is discussed.     

Natural orifice translumenal endoscopic surgery (NOTES) navigation performance: a pilot study comparing surgeons and gastroenterologists

BACKGROUND: As an emerging surgical paradigm, NOTES is currently performed using conventional flexible endoscopes. Gastroenterologists are experts in handling this instrument; however, NOTES involves manipulation of the endoscope outside the lumen of the gastrointestinal tract. Surgeons are used to operating within the spatial environment of the peritoneal cavity. The aim of this study was to investigate whether either surgeons or gastroenterologists are superior at navigating the endoscope in a NOTES environment using the Imperial College Natural Orifice Simulated surgical Environment (NOSsE) as an assessment tool. METHODS: Nine novices, 5 gastroenterologists and 4 laparoscopic surgeons were recruited to navigate through a series of targets in the NOSsE phantom. End-points were time taken to complete the course and number of targets successfully visualised. RESULTS: Gastroenterologists and surgeons completed the course faster (p < 0.001) and revealed more targets than novices (p < 0.001). Overall, surgeons completed the course in less time than gastroenterologists (mean time 228 sec vs. 134 sec; p = 0.172) and visualised more targets (mean 8.83 vs. 7.53; p = 0.217) although neither reached statistical significance. CONCLUSIONS: The results of this pilot study suggest that surgeons are not disadvantaged when it comes to navigating an endoscope within a simulated NOTES environment compared to gastroenterologists. Therefore, as appears to be the current practice, it is acceptable for surgical teams to perform initial NOTES studies, provided they possess adequate skill, appropriate laboratory experience and ethical review board approval. With the evolution in surgical tools, we are likely to see improved instrumentation to aid in navigation in NOTES.     

Human NOTES Cholecystectomy: Transgastric Hybrid Technique

Background  Natural orifice translumenal endoscopic surgery (NOTES) is an emerging field in minimally invasive surgery that is driving the development of new technology and techniques. There are several proposed benefits to the NOTES approach, including potentially decreased abdominal pain, wound infections, and hernia formation Ko and Kalloo (Chin J Dig Dis 7:67–70, 2006); Wagh et al. (Clin Gastroenterol Hepatol 3(9):892–896, 2005); ASGE/SAGES Working Group on Natural Orifice Transluminal Endoscopic Surgery (Gastrointest Endosc 63(2):199–203, 2006); and Pearl and Ponsky (J GI Surg 12:1293–1300, 2008). Cholecystectomy has been one of the most commonly performed NOTES procedures to date, with the majority being performed through the transvaginal approach Marescaux et al. (Arch Surg 142:823–826, 2007); Zorron et al. (Surg Endosc 22:542–547, 2008); and Ramos et al. (Endoscopy 40:572–575, 2008). Transgastric approaches for cholecystectomy have been shown to be technically feasible in animal models and in several unpublished human patients Sumiyama et al. (Gastrointest Endosc 65(7):1028–1034, 2007). This video demonstrates the technique by which we perform transgastric NOTES hybrid cholecystectomy in human patients. Method  Patients with symptomatic gallstone disease are enrolled under an IRB approved protocol. A diagnostic EGD is performed to confirm normal anatomy. Peritoneal access is gained using a needle-knife cautery and balloon dilation under laparoscopic visualization. Dissection of the critical view of safety is performed endoscopically. The cystic duct and artery are clipped laparoscopically and the gallbladder is dissected off of the liver. The gastrotomy is closed intralumenally and over-sewed laparoscopically. The gallbladder is extracted out the mouth. Results  This technique was used to successfully perform four NOTES hybrid transgastric cholecystectomies without operative complications. Conclusions  NOTES hybrid transgastric cholecystectomy can be performed safely in human patients. This procedure is still technically challenging given the current instrumentation that is available. In order to perform a pure NOTES transgastric cholecystectomy, a safe blind access method, improved retraction, endoscopic hemostatic clips, and reliable closure methods need to be developed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Presented at SSAT/DDW, May 2008, San Diego, CA.