Developing essential tools to enable transgastric surgery. Surg Endosc. 2008;22:600-604. [PMID: 17973169 DOI: 10.1007/s00464-007-9632-y]

Mini-laparoscopic cholecystectomy with the MiniLap® percutaneous surgical system: a series of 32 patients

Background

In recent years, mini-laparoscopic procedures are gaining the preference of most surgeons due to their potentially better surgical outcomes. The Mini Lap Percutaneous Surgical System with MiniGrip^® Handle is currently the less invasive instrument and can be applied to a wide range of operations. The current paper presents its application on percutaneous laparoscopic cholecystectomy.

Materials and methods

From January 2017 to June 2017, 32 patients underwent percutaneous laparoscopic cholecystectomy with the MiniLap^® system. All operations were performed by the same surgical team.

Results

No conversions and no overall complications were reported. Drainage were not necessary. Mean surgical time was 35 minutes, while patients were released in <24 hours after the operation.

Conclusion

The MiniLap system with the use of the mini grip handle seems to sustain the benefits of performing laparoscopically. However, further trials should be conducted so as to establish its safety on cholecystectomies.

Choice of handedness and automated suturing for anthropomorphic dual-arm surgical robots

Laparoscopic and Single Port Access Surgery (SPAS) present unique dexterity challenges related to dual-arm operations in confined spaces and tele-manipulation of highly dexterous surgical slaves. In an effort to reduce tele-manipulation burden, new paradigms for semi-automating surgical tasks are needed. This paper presents a new minimal constraint suturing and automated choice of handedness for anthropomorphic dual-arm robots. The automated choice of handedness supports surgeons during tele-manipulation of complex robotic slaves where dexterity and workspace constraints are difficult to learn. This criterion is also used to support automated dual-arm rendezvous for quicker suture exchange during dual-arm suturing. The minimal constraint algorithm presented in this paper allows surgeons to operate within a shared-control tele-manipulation framework whereby the surgeon controls the needle insertion speed and the robot controls the needle orientation while respecting a minimalistic set of tissue constraints. This framework is evaluated on a novel insertable robotic end-effectors platform for SPAS. A simulation study demonstrates the effectiveness of the automated choice of handedness criterion through a study of dexterity limitations of each arm. Additional simulations show the proposed algorithm for automated rendezvous and suture exchange.

Natural-orifice transluminal endoscopic surgery

BACKGROUND

Natural-orifice transluminal endoscopic surgery (NOTES) represents one of the most significant innovations in surgery to emerge since the advent of laparoscopy. A decade of progress with this approach has now been catalogued, and yet its clinical application remains controversial.

METHODS

A PubMed search was carried out for articles describing NOTES in both the preclinical and the clinical setting. Public perceptions and expert opinion regarding NOTES in the published literature were analysed carefully.

RESULTS

Two hundred relevant articles on NOTES were studied and the outcomes reviewed. A division between direct- and indirect-target NOTES was established. The areas with the most promising clinical application included direct-target NOTES, such as transanal total mesorectal excision and peroral endoscopic myotomy. The clinical experience with distant-target NOTES, such as for appendicectomy and cholecystectomy, showed feasibility; however, NOTES-specific morbidity was introduced and this represents an important limitation.

CONCLUSION

NOTES experimentation in the preclinical setting has increased substantially. There has also been a significant increase in the application of NOTES in humans in the past decade. Enthusiasm for NOTES should be tempered by the risk of incurring NOTES-specific morbidity. Surgeons should carefully consider patient preferences regarding this new minimally invasive option, as opinions are not unanimously supportive of NOTES. As technical limitations are overcome, the clinical application of NOTES is predicted to increase. It is paramount that, when this complex technique is performed on humans, it is applied judiciously by appropriately trained experts with outcomes recorded in a registry.

Beyond the "B": a new concept of the surgical staple enabling miniature staplers

Background

Surgical staplers currently all rely on the same staple form—the “B” which necessitates a high delivery profile (12 mm). A novel “D” shape staple allows for an extremely low profile of the applicator. The acute and long-term efficacy of a D-shaped staple (Cardica, Redwood City, CA, USA) was compared to conventional B-form staples (Covidien, Norwalk, CN, USA) in an animal model for intestinal transections and anastomoses.

Methods

Jejunojejunal anastomoses (JJ) were performed via mini-laparotomy in a swine model. White & blue D- and B-shaped staples were studied in three groups (planned survival 14–84 days). Intraoperative assessment included completeness of staple line, hemostasis, and need for intervention. Postoperatively, animals were evaluated for complications. At the time of sacrifice, gross pathological and histological assessments were performed.

Results

Twenty-three animals had 40 anastomoses (23 “D” and 17 “B” staple anastomoses) with no intraoperative mortalities. One “D” staple application required a manual extension of the cut. Acute hemostasis was 100 %. Group 1 (n = 5) compared white staples in JJs (D staple n = 5; B staple n = 5; 14-day survival = 100 %). Group 2 (n = 12) compared white staples in JJs (D staple n = 12; B staple n = 6; 34-day survival = 92 %). One animal died on day 4 for a non-staple related cause. Group 3 (n = 6) compared blue staples in JJs (D staple n = 6; B staple n = 6; 84 day survival = 84 %). One animal died on day 18 due to an obstruction at the B staple JJ caused by stricture. There were no other bleeding, leaks or strictures in any of the groups. Gross pathology and histology were unremarkable in all JJs.

Conclusions

This study showed no difference in intraoperative performance and the chronic healing response in JJs between D- and B-shaped staples. Based on these findings, the D-shaped staple elicits a normal healing response in jejunostomies and offers the possibility of clinical use of this advance in staple design.

A state of the art review and categorization of multi-branched instruments for NOTES and SILS

BACKGROUND

Since the advent of Natural Orifice Translumenal Endoscopic Surgery (NOTES) and single incision laparoscopic surgery (SILS), a variety of multitasking platforms have been under development with the objective to allow for bimanual surgical tasks to be performed. These instruments show large differences in construction, enabled degrees of freedom (DOF), and control aspects.

METHODS

Through a literature review, the absence of an in-depth analysis and structural comparison of these instruments in the literature is addressed. All the designed and prototyped multitasking platforms are identified and categorized with respect to their actively controlled DOF in their shafts and branches. Additionally, a graphical overview of patents, bench test experiments, and animal and/or human trials performed with each instrument is provided.

RESULTS

The large range of instruments, various actuation strategies, and different direct and indirect control methods implemented in the instruments show that an optimal instrument configuration has not been found yet. Moreover, several questions remain unanswered with respect to which DOF are essential for bimanual tasks and which control methods are best suited for the control of these DOF.

CONCLUSIONS

Considering the complexity of the currently prototyped and tested instruments, future NOTES and SILS instrument development will potentially necessitate a reduction of the available DOF to minimize the control complexity, thereby allowing for single surgeon bimanual task execution.

Transanal natural orifice transluminal endoscopic surgery total mesorectal excision in animal models: endoscopic inferior mesenteric artery dissection made easier by a retroperitoneal approach

Purpose

We report the performance of natural orifice transluminal endoscopic surgery (NOTES) low anterior resection in animals using transanal total mesorectal excision (TME) with laparoscopic assistance and endoscopic inferior mesenteric artery (IMA) dissection.

Methods

Four pigs weighing 45 kg each, and one dog weighing 25 kg, underwent surgery via a transanal approach. The rectum was occluded transanally using a purse-string suture, approximately 3-4 cm from the anal verge. The rectal mucosa was incised circumferentially just distal to the purse-string. A SILS or GelPOINT port was inserted transanally. Transanal TME was assisted by laparoscopy and proceeded up to the peritoneal reflection. More proximal dissection, including IMA dissection, was performed along the retroperitoneal avascular plane by endoscopy alone and facilitated by CO₂ insufflation. The IMA was clipped and divided endoscopically. The mobilized rectosigmoid were exteriorized transanally and transected. A colorectal anastomosis was performed using a circular stapler with a single stapling technique.

Results

Endoscopic dissection of the IMA was successful in all five animals. The mean operation time was 125 minutes (range, 90-170 minutes). There were no intraoperative complications or hemodynamic instability. The mean length of the resected specimen was 14.4 cm (range, 12-16 cm).

Conclusion

A NOTES retroperitoneal approach to the IMA with CO₂ insufflation and intact peritoneal covering overcame the difficulties of retraction and exposure of endoscopic dissection in animals.

Mastering instruments before operating on a patient: the role of simulation training in tool use skills

BACKGROUND

We examined the impact of tool complexity on surgeons' performance and evaluated the value of using a simulation-based program for reducing training cost.

METHODS

Three pairs of surgical graspers with increasing mechanical complexity, which were designed for open, laparoscopic, and endoscopic procedures, were used in performing a simple object transportation task. Task times and mental workload of 17 surgeons were compared using all 3 variations of the graspers to test the impact of tool complexity on surgical performance. Subsequently, 4 of these surgeons decided to enter a 3-week training phase and practiced with these 3 surgical instruments on a daily basis. Learning curves were plotted to examine the value of using simulation for proficiency training with these tools.

RESULTS

Task time was significantly prolonged as tool complexity increased. Practice in a simulated environment shortened the task time significantly and moderately reduced mental workloads. However, the difference in task time varied among the 3 types of tools. Between days 1 and 9, task times for each types of grasper were reduced by 55% (endoscopic), 42% (open), and 22% (laparoscopic).

CONCLUSIONS

Tool complexity may degrade a surgeon's performance. Extensive simulation training programs are important for surgeons to gain proficiency in handling a tool before they practice on patients.

Improvements in robotic natural orifice surgery with a novel material handling system

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) has many potential advantages over other minimally invasive surgical techniques, but it presents a number of challenges introduced by the restrictive natural access points. Fully insertable dexterous in vivo robots have been developed that eliminate the spatial restrictions of the entry point, but they also are isolated within the abdomen. A material handling system (MHS) developed to bridge the gap between the in vivo robots and the surgical team promises a number of improvements over other current technologies.

METHODS

The MHS was implemented with two different nonsurvival swine models to validate the utility and benefits of the system. The first procedure was attempted transgastrically but proved too difficult because the geometry of the esophagus was prohibitively small. The system was instead inserted via a 50-mm GelPort and tested for robustness. The second procedure used a transvaginal insertion via a custom 25-mm trocar. Throughout both procedures, the practitioners were asked for qualitative feedback regarding the effectiveness of the device and its long-term efficiencies.

RESULTS

The MHS was able to deliver a standard surgical staple securely to the peritoneal cavity. The practitioner was able to use the laparoscopic grasper both to insert and to remove the staple from the MHS. The system also proved capable of maintaining insufflation pressure throughout a procedure. It was cycled a total of five times in both the insertion and the retraction directions. Visualization from the MHS camera was poor at times because the lighting on the system was somewhat inadequate. No excessive bleeding or collateral damage to surrounding tissues was observed during the procedure.

CONCLUSIONS

This study demonstrated that the MHS is fully capable of achieving payload transport during a NOTES operation. The system is intuitive and easy to use. It dramatically decreases collateral trauma in the natural access point and can advantageously reduce the overall duration of a procedure.

Euro-NOTES Status Paper: from the concept to clinical practice

BACKGROUND

The concept of natural orifice transluminal endoscopic surgery (NOTES) consists of the reduction of access trauma by using a natural orifice access to the intra-abdominal cavity. This could possibly lead to less postoperative pain, quicker recovery from surgery, fewer postoperative complications, fewer wound infections, and fewer long-term problems such as hernias. The Euro-NOTES Foundation has organized yearly meetings to work on this concept to bring it safely into clinical practice. The aim of this Euro-NOTES status update is to assess the yearly scientific working group reports and provide an overview on the current clinical practice of NOTES procedures.

METHODS

After the Euro-NOTES meeting 2011 in Frankfurt, Germany, an analysis was started regarding the most important topics of the European working groups. All prospectively documented information was gathered from Euro-NOTES and D-NOTES working groups from 2007 to 2011. The top five topics were analyzed.

RESULTS

The statements of the working group activities demonstrate the growing information and changing insights. The most important selected topics were infection issue, peritoneal access, education and training, platforms and new technology, closure, suture, and anastomosis. The focus on research topics changed over time. The principle of hybrid access has overcome the technical and safety limitations of pure NOTES. Currently the following NOTES access routes are established for several indications: transvaginal access for cholecystectomy, appendectomy and colon resections; transesophageal access for myotomy; transgastric access for full-thickness small-tumor resections; and transanal/transcolonic access for rectal and colon resections.

CONCLUSIONS

NOTES and hybrid NOTES techniques have emerged for all natural orifices and were introduced into clinical practice with a good safety record. There are different indications for different natural orifices. Each technique has been optimized for the purpose of finding a safe and realistic solution to perform the procedure according to the specific indication.

Dimensionality Reduction in Controlling Articulated Snake Robot for Endoscopy Under Dynamic Active Constraints

This paper presents a real-time control framework for a snake robot with hyper-kinematic redundancy under dynamic active constraints for minimally invasive surgery. A proximity query (PQ) formulation is proposed to compute the deviation of the robot motion from predefined anatomical constraints. The proposed method is generic and can be applied to any snake robot represented as a set of control vertices. The proposed PQ formulation is implemented on a graphic processing unit, allowing for fast updates over 1 kHz. We also demonstrate that the robot joint space can be characterized into lower dimensional space for smooth articulation. A novel motion parameterization scheme in polar coordinates is proposed to describe the transition of motion, thus allowing for direct manual control of the robot using standard interface devices with limited degrees of freedom. Under the proposed framework, the correct alignment between the visual and motor axes is ensured, and haptic guidance is provided to prevent excessive force applied to the tissue by the robot body. A resistance force is further incorporated to enhance smooth pursuit movement matched to the dynamic response and actuation limit of the robot. To demonstrate the practical value of the proposed platform with enhanced ergonomic control, detailed quantitative performance evaluation was conducted on a group of subjects performing simulated intraluminal and intracavity endoscopic tasks.

Biopsy with thermally-responsive untethered microtools

Thermally activated, untethered microgrippers can reach narrow conduits in the body and be used to excise tissue for diagnostic analyses. As depicted in the figure, the feasibility of an in vivo biopsy of the porcine bile duct using untethered microgrippers is demonstrated.

Magnetic instrumentation and other applications of magnets in NOTES

Modern surgery is developing towards a minimally invasive approach. To minimize the trauma the number of ports is either limited as in single incision laparoscopic procedures or ports are introduced through natural orifices as in natural orifice translumenal endoscopic surgery (NOTES). To provide surgeons with appropriate instrumentation novel technologies are employed involving magnets. This article summarizes the theoretical background, technology and currently developed magnetic instrumentation for NOTES, laparoscopic surgery and endoscopy. Moreover, current limitations and future goals are addressed to outline the prospects for use of magnetic instrumentation in the surgery of tomorrow.

Selective automation and skill transfer in medical robotics: a demonstration on surgical knot-tying

BACKGROUND

Transferring non-trivial human manipulation skills to robot systems is a challenging task. There have been a number of attempts to design research systems for skill transfer, but the level of the complexity of the actual skills transferable to the robot was rather limited, and delicate operations requiring a high dexterity and long action sequences with many sub-operations were impossible to transfer.

METHODS

A novel approach to human-machine skill transfer for multi-arm robot systems is presented. The methodology capitalizes on the metaphor of 'scaffolded learning', which has gained widespread acceptance in psychology. The main idea is to formalize the superior knowledge of a teacher in a certain way to generate support for a trainee. In our case, the scaffolding is constituted by abstract patterns, which facilitate the structuring and segmentation of information during 'learning by demonstration'. The actual skill generalization is then based on simulating fluid dynamics.

RESULTS

The approach has been successfully evaluated in the medical domain for the delicate task of automated knot-tying for suturing with standard surgical instruments and a realistic minimally invasive robotic surgery system.

Transgastric small bowel resection with the new multitasking platform EndoSAMURAI™ for natural orifice transluminal endoscopic surgery

BACKGROUND

Recently, natural orifice transluminal endoscopic surgery has been introduced using flexible endoscopic technology. Traditional endoscopes lack several capabilities that are needed to perform complex surgical procedures safely. The purpose of this study was to evaluate the new multitasking platform for transgastric small bowel resection including dissection of the mesentery and suturing an anastomosis.

METHODS

A new prototype of endoscopic multifunctional platform, EndoSAMURAI™ (ES), was tested. A standardized in vitro setting was established with segments of small bowel and an anastomosis was sutured with the device and compared with that by stapler (ST) and hand-sewn (HS). Leak pressure was measured. In addition, the system was tested in an experimental in vivo situation by performing a transgastric small bowel segmental resection under general anesthesia.

RESULTS

Median time to perform an anastomosis in the bench test was 41 min; median leak pressure for the anastomosis by ES was 14 mmHg, by ST 25 mmHg, and HS 15 mmHg. For the in vivo study, the median total procedure time was 110 min and leak pressure 53 mmHg. These results show that the end-to-end small bowel anastomosis can be sutured sufficiently.

CONCLUSIONS

This study has shown that with a multifunctional platform such as the EndoSAMURAI™, the majority of complex surgical tasks can be performed if technically independently moving instruments can be used via an ergonomic workstation interface that allows for laparoscopy-like maneuvers by the operator. Even with the shortcomings of the prototype, it was possible to perform an anastomosis of the small bowel of acceptable quality within a reasonable time.

Natural Orifice Surgery (NOS)-the next step in the evolution of minimally invasive surgery

Endoscopy, which was introduced in the 20(th) century, changed the outcome of surgery by reducing the need for analgesia and shortening hospital stay. Any new surgical method should improve safety and outcome. At the beginning of the 21(st) century, the use of natural orifice surgery is a promising progress. The transgastric and transdouglas approaches are currently being investigated and evaluated. The transgastric approach still has a long way to go due to objective problems such as infections, stomach acidity, and the optimal way to ensure the safe closure of gastrotomy. The transdouglas approach, however, is already starting to establish itself and it seems that with the construction of designated instruments it will prevail in the 21(st) century.

Self-folding devices and materials for biomedical applications

Because the native cellular environment is 3D, there is a need to extend planar, micro- and nanostructured biomedical devices to the third dimension. Self-folding methods can extend the precision of planar lithographic patterning into the third dimension and create reconfigurable structures that fold or unfold in response to specific environmental cues. Here, we review the use of hinge-based self-folding methods in the creation of functional 3D biomedical devices including precisely patterned nano- to centimeter scale polyhedral containers, scaffolds for cell culture and reconfigurable surgical tools such as grippers that respond autonomously to specific chemicals.

Natural orifice transluminal endoscopic surgery: New minimally invasive surgery come of age

Although in the past two decades, laparoscopic surgery, considered as a great revolution in the minimally invasive surgery field, has undergone major development worldwide, another dramatic surgical revolution has quietly appeared in recent years. Ever since Kalloo’s first report on transgastric peritoneoscopy in a porcine model in 2004, interest in a new surgical procedure named natural orifice transluminal endoscopic surgery (NOTES) has blossomed worldwide. Considering that a NOTES procedure could theoretically avoid any abdominal incision, operation-related pain and scarring, many surgeons and endoscopists have been enthusiastic in their study of this new technique. In recent years, several NOTES studies have been carried out on porcine models and even on humans, including transvaginal cholecystectomy, transgastric appendectomy, transvaginal appendectomy, and transvesical peritoneoscopy. So what is the current situation of NOTES and how many challenges do we still face? This review discusses the current research progress in NOTES.

Survey on surgical instrument handle design: ergonomics and acceptance

Minimally invasive surgical approaches have revolutionized surgical care and considerably improved surgical outcomes. The instrumentation has changed significantly from open to laparoscopic and robotic surgery with various usability and ergonomics qualities. To establish guidelines for future designing of surgical instruments, this study assesses the effects of current surgical approaches and instruments on the surgeon. Furthermore, an analysis of surgeons' preferences with respect to instrument handles was performed to identify the main acceptance criteria. In all, 49 surgeons (24 with robotic surgery experience, 25 without) completed the survey about physical discomfort and working conditions. The respondents evaluated comfort, intuitiveness, precision, and stability of 7 instrument handles. Robotic surgery procedures generally take a longer time than conventional procedures but result in less back, shoulder, and wrist pain; 28% of surgeons complained about finger and neck pain during robotic surgery. Three handles (conventional needle holder, da Vinci wrist, and joystick-like handle) received significantly higher scores for most of the proposed criteria. The handle preference is best explained by a regression model related only to comfort and precision (R(2) = 0.91) and is significantly affected by the surgeon's background (P < .001). Although robotic surgery seems to alleviate physical discomfort during and after surgery, the results of this study show that there is room for improvement in the sitting posture and in the ergonomics of the handles. Comfort and precision have been found to be the most important aspects for the surgeon's choice of an instrument handle. Furthermore, surgeons' professional background should be considered when designing novel surgical instruments.

Natural Orifice Translumenal Endoscopic Surgery (NOTES) in urology

The concept of endoscopic surgery performed through natural orifices - Natural Orifice Translumenal Endoscopic Surgery (NOTES) - represents one of the most exciting ideas recently introduced in surgery. The use of natural orifice as a transluminal access to the peritoneal cavity has been shown to be effective and reproducible. After the introduction of the transgastric access (2004), the adaptation of the well-known transvaginal access, looking for ideal and more suitable entrance has led to the development of the transcolonic and transvescical ports. To date, the NOTES technique showed its full potential in experimental models, so as to allow the completion of most of the standard procedures performed in laparoscopic technique and thus opening the door to a new era, considered as "3rd generation surgery". However, only few experiences have been translated to humans and this concept is still at an early stage of experimental development. Many efforts are still needed to establish the standardization and validation of the techniques, the verification of safety and effectiveness. ?This article intends to photograph the actual role of NOTES, reviewing its history, analyzing the potential benefits and drawbacks, browsing and comparing the different transluminal routes, describing the equipment and platforms currently available, and finally to point out the state of the art of NOTES in the urological field.

Transgastric small bowel resection and anastomosis: a survival study

BACKGROUND

Recently, natural orifice transluminal endoscopic surgery has emerged with new ideas of a transgastric access. The authors have evaluated the possibility of transgastric bowel resection with several modifications. This study aimed to evaluate transgastic small bowel resection using an automated stapling device via an assisting trocar. In a survival experiment, the possible technical problems, medical complications, and safety of the procedure were investigated as well as the postoperative course and follow-up care.

METHODS

The study protocol was submitted to the animal research committee and approved. A total of 13 swine with a body weight of 25 kg (range, 20-46 kg) were investigated and entered into the study. General anesthesia was induced by certified personnel using ketamine, halothan, oxygen, and nitrous oxide. One trocar was used for laparoscopic assistance. A needleknife was used to complete a 1.5-cm-long gastrotomy. The gastroscope was advanced into the peritoneal cavity, and a small bowel loop was identified. Through the second channel of the scope, a coag-grasper was used to dissect the mesentery. A linear stapler was inserted through the assisting trocar, and the resection was performed. Afterward, the bowel ends were reopened, and the stapler was reinserted for a side-to-side anastomosis. The specimen was removed via the stomach. Gastric closure was completed using laparoscopic mini-instruments. All problems were prospectively documented. Follow-up evaluation was performed over 2 weeks. The animals were killed and reopened, and evidence of adhesions, infection, and abscess formation was evaluated.

RESULTS

In this study, 13 female animals with a body weight of 25 kg (range, 20-46 kg) underwent surgery. No mortality or postoperative complications occurred. The animals had stable weight development. After a follow-up period of 2 weeks, the animals were killed. The findings included minor adhesions, no abscess, and no inflammation.

CONCLUSION

Transgastric bowel resection with minor laparoscopic assistance is a safe experimental procedure when performed by surgeons with adequate and extensive training. These experimental procedures should be evaluated carefully and critically in clinical practice.

Technical and equipment challenges for laparoendoscopic single-site surgery and natural orifice transluminal endoscopic surgery

Laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES™) are new approaches to minimally invasive surgery. A number of technical challenges need to be overcome and new developments of equipment are required before widespread acceptance of either modality occurs. In this paper we discuss novel approaches and innovations as well as review examples of equipment and platforms that have previously been used for LESS and NOTES. Emphasis is given to urological applications.

Transgastric small bowel resection by using hybrid technique — Experimental study

Introduction:The Natural Orifice Transluminal Endoscopic Surgery (NOTES) is an abdominal operation carried out with flexible endoscopic instruments and their advanced versions via natural orifices. The NOTES causes theoretically less pain, operative stress, shorter hospitalization, quicker recovery and it is scarless. The aim of this investigation was to evaluate the feasibility and safety of transgastric small bowel resection. Materials and methods: Seven domestic pigs were investigated and entered the study; body weight 25 kg in average. General anesthesia was performed. One trocar was used for laparoscopic observations during gastrotomy and transgastric penetration with the gastroscope, later for assistance with a grasper for manipulation of the bowel loops and for the application of the linear stapling device. Then the needle knife was used to complete a 1.5 cm long incision in the gastric wall. The gastroscope was advanced into the peritoneal cavity and a small bowel loop was identified and elevated with a flexible grasper. Through the second channel of the scope a coag grasper was used to dissect the mesentery. Then a linear stapler was inserted through the assisting trocar and the resection was performed. Afterwards the bowel ends were opened with the needle knife and the stapler was reinserted for a side-to-side anastomosis. The specimen was removed via the stomach. Gastric closure was completed by laparoscopic mini-instruments through the stapler-port. All special events and all problems were prospectively documented. Follow-up was performed over 2 weeks and body weight was recorded. Then a laparoscopy was performed to document adhesions or abscess formation. Finally the animals were sacrificed to evaluate further evidence of infection or adhesions. Results: The operations were carried without complications, there was no case of letal outcome. On the 12th day the abdominal laparoscopic revision was carried out, after the revision in one case adhesion could be detected, no other kinds of complications were noticed. Conclusion: According to our results, the transgastric small bowel resection is a safe procedure, but further special instruments are needed. These experimental procedures should be evaluated carefully and critically in clinical practice.

Natural orifice translumenal surgery: Flexible platform review

Natural orifice translumenal surgery (NOTES) has garnished significant attention from surgeons and gastroenterologists, due to the fusion of flexible endoscopy and operative technique. Preliminary efforts suggest that NOTES holds potential for a less invasive approach with certain surgical conditions. Many of the hurdles encountered during the shift from open to laparoscopic surgery are now being revisited in the development of NOTES. Physician directed efforts, coupled with industry support, have brought about several NOTES specific devices and platforms to help address limitations with current instrumentation. This review addresses current flexible platforms and their attributes, advantages, disadvantages and limitations.

Control of articulated snake robot under dynamic active constraints

Flexible, ergonomically enhanced surgical robots have important applications to transluminal endoscopic surgery, for which path-following and dynamic shape conformance are essential. In this paper, kinematic control of a snake robot for motion stabilisation under dynamic active constraints is addressed. The main objective is to enable the robot to track the visual target accurately and steadily on deforming tissue whilst conforming to pre-defined anatomical constraints. The motion tracking can also be augmented with manual control. By taking into account the physical limits in terms of maximum frequency response of the system (manifested as a delay between the input of the manipulator and the movement of the end-effector), we show the importance of visual-motor synchronisation for performing accurate smooth pursuit movements. Detailed user experiments are performed to demonstrate the practical value of the proposed control mechanism.

[Diagnostic and interventional endoscopy in gastroenterology : from high-resolution chips and procedures for endoscopic resection to NOTES]

In the past 10 years endoscopic diagnostics has benefited from technologies such as big chips, high-definition television (HDTV) and narrow band imaging (NBI). Video capsule endoscopy and double balloon enteroscopy have facilitated visualization of the entire small bowel. A number of studies on mucosal Barrett's and gastric cancers could prove that endoscopic mucosal resection (EMR) is oncologically equivalent to surgical resection when certain criteria are respected. However, EMR is less invasive and carries a substantially lower complication risk and mortality compared to surgery. Endoscopic submucosal dissection (ESD) facilitates en bloc resection with thorough histopathologic evaluation of the specimen, e.g. for mucosal lesions in the stomach and rectum. Endosonography (EUS) guided transgastric necrosectomy using a flexible gastroscope has set a milestone in the treatment of infected pancreatic necroses and has replaced open surgery in many centers. Natural orifice transluminal endoscopic surgery (NOTES) uses natural body openings as minimally invasive access to the abdomen and mediastinum. Interventional GI endoscopists and minimally invasive surgeons have profited from these innovations in micromechanics and microelectronics.

NOTES: new dimension of minimally invasive surgery

Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery. NOTES eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. Since the first NOTES was reported by Kalloo et al. in 2004, significant achievements in the laboratory have occurred. Clinical use in humans has been limited, but several cases and one small clinical trial were published recently. As a further technical revolution in minimally invasive surgery, NOTES has the promising potential to be safer, less invasive, provide better cosmesis and possibly be more cost-effective. The purpose of the present article was to review the development and current status of NOTES and highlight important advances associated with this innovative approach.

[The future of gastrointestinal therapeutic endoscopy: NOTES]

Natural orifice translumenal endoscopic surgery (NOTES) allows access into the peritoneal cavity with a flexible endoscope, through the wall of the digestive or urogenital tracts. NOTES can be combined to laparoscopic surgery in so-called << hybrid >> techniques. In the absence of any incision of the abdominal wall, NOTES procedures provide perfect cosmetic results, with virtually no risk of parietal complications, and with decreased postoperative pain. NOTES could particularly benefit to overweight patients and to patients receiving intensive or palliative care. Most NOTES studies have been performed on animal models, with great interest for both transgastric and transpelvic approaches. Successful NOTES peritoneoscopy, hysterectomy, oophorectomy, tubal ligation, gastrojejunal anastomosis, cholecystectomy, splenectomy, nephrectomy, and abdominal-wall hernia repair have been described. In human studies, the transvaginal route is preferred. NOTES clinical research focuses on low-morbidity procedures, such as cholecystectomy, appendectomy, and peritoneoscopy. Indirect benefits are expected from this research, with possible technological innovations in the field of endoscopic instrumentation (including sutures, anastomosis, traction and triangulation). Overall, NOTES is believed to make evolve both interventional endoscopy and minimally invasive surgery.

The natural orifice simulated surgical environment (NOSsE): exploring the challenges of NOTES without the animal model

In this paper, we introduce an inexpensive, realistic, and robust simulator model for training and requirement assessment of natural orifice transluminal endoscopic surgery (NOTES). A laparoscopic box trainer is converted into an effective NOTES environment, in which many of the challenges facing this new approach can be explored first hand in a laboratory setting. Using this simulator, experiments researching this new surgical field can be refined before moving into in vivo trials, such that the number of animals required for acquiring basic skills and validating new surgical protocols can be reduced. Additionally, the simulator has the potential to be utilized as an effective platform for education and training in NOTES, although formal validation is required before this can truly be appreciated.

Hybrid NOTES transvaginal cholecystectomy: operative and long-term results after 18 cases

PURPOSE

Natural orifice transluminal endoscopic surgery (NOTES) is a novel technique that aims at reducing or abolishing skin incisions and potentially also postoperative pain. The purpose of this study was to analyse operative and long-term results of a series of hybrid transvaginal cholecystectomy.

MATERIALS AND METHODS

Between July 2007 and May 2009, transvaginal NOTES cholecystectomy for symptomatic cholelithiasis was performed by a hybrid technique in 18 women (mean age 54 years), including four women with a body mass index >30 kg/m(2). Dissection was conducted in the first four cases by a round-tip unipolar electrode (UE) introduced through the operative channel of the endoscope coming from the vagina and in the last 14 cases by a ultrasonic scalpel (US) introduced through a 5-mm abdominal port. The short-term outcomes and the long-term results of the two methods were compared.

RESULTS

The transvaginal approach entailed no intraoperative complication and no conversion. The overall mean duration of procedures was 75 min (range 40-190). In the first four cases (UE), the operating time was 148 min (range 140-190), whilst in the last 14 (US), it was considerably shorter, 53 min (range 40-60, p < 0.01). We experienced one biliary leak in the UE group, whilst morbidity with US was nil (p < 0.005). The biliary leak healed in 7 days with nasobiliary drainage. No other complications were encountered in either group. The mean follow-up was 12 months (range 1-22), and none of the patients has complained of dyspareunia or other colpotomy-related complications so far.

CONCLUSIONS

Until specifically designed endoscopic tools are available for NOTES, the hybrid technique with US dissection conducted through a 5-mm port should be preferred in transvaginal cholecystectomy in order to shorten the duration of surgery and make this approach effective, safe and reproducible. After a mean follow-up of 1 year, none of our patients has complained of any problem related to transvaginal approach.

Navigation systems and platforms in natural orifice translumenal endoscopic surgery (NOTES)

INTRODUCTION

The latest evolution in minimally invasive surgery is to avoid skin incisions by using natural orifices, called natural orifice translumenal endoscopic surgery (NOTES). However, to safely and efficiently perform NOTES, the requirements of the operating platform used need to be modified from the conventional endoscope. The aim of this paper is to systematically review specialised operating platforms used or in development for NOTES procedures.

METHODS

A review of the literature was conducted using Ovid EMBASE, Ovid MEDLINE, ISI Current Contents Connect and PubMed, a search tool of the National Library of Medicine and the national institute of Health, until the 1st of December 2008. Data was extracted to specifically characterise the available platforms, their availability, advantageous characteristics and potential disadvantages.

RESULTS

There were 9 studies included in this review describing 6 different navigation platforms and 3 robotic systems for NOTES. Based on this analysis, it is our opinion that although the described surgical systems and navigation platforms possess some attractive characteristics, such as maneuverability, stability, enhanced optics, and the ability to provide triangulation and insufflation with proper suction/irrigation maintenance, there does not appear to be one platform which is clearly superior to others.

CONCLUSION

Current instruments are not suited for effective surgery in a NOTES environment. There are several important requirements for NOTES platform: 1) to provide safe access to the peritoneal cavity; 2) to provide a stable channel for instrumentation passageway and safe navigation, 3) to provide good visualization and illumination, thereby decreasing disorientation, 4) to maintain proper insufflation and suction/irrigation, and 5) to provide maneuverability and triangulation of the instruments. Effective collaborations between clinicians, engineering departments and industry are essential to maximise and expedite the innovative process in producing an optimal NOTES platform.

Development and validation of a new generation of flexible endoscope for NOTES

BACKGROUND

The concept of intraperitoneal flexible endoscopy has created much interest and investigation. Both gastroenterologists with a surgical leaning and surgeons with advanced endoscopy interests are researching the feasibility of this new approach. Current flexible scopes and instruments are extremely limited for use in natural orifice transluminal endoscopic surgery (NOTES). We describe the development of an endoscopic system specifically designed for endoluminal and NOTES procedures and demonstrates benefits and efficacy in benchtop and cadaver models.

TECHNIQUE

In conjunction with industry, an 18-mm 4-channel rigidizing access device was designed. Measurements of the strength (torsional and lifting) of standard endoscopes and the new scope were made. The new device and instruments are used in 8 cadavers to document its feasibility in a variety of specific tasks: endoluminal plication, upper abdomen and lower abdomen visualization, bowel manipulation, solid organ retraction, cholecystectomy, and enterotomy closure.

RESULTS

Benchtop comparison between a standard scope and the new scope showed equal maneuverability but the newer scope had greater force delivery at the tip (0.042 vs 1.96 lb, P < .001) and greater instrument application force (0.09 vs 0.23 lb, P < .002). Introduction of the scope was possible in all cadavers but difficult in cadavers <60 kg. Intragastric manipulation was feasible and exiting the stomach was possible although it required a 2-cm gastrotomy. The scope system was maneuverable in both lower quadrants without difficulty. The upper abdomen was viewable, with variable success in steering the scope between left and right quadrants. The entire gastrointestinal tract was able to be visualized in most cadavers. The scope generated sufficient force to lift and manipulate intraabdominal structures. Cholecystectomy was successful in 5 of 5 attempts.

CONCLUSION

A new flexible access endoscope with 4 large access channels showed utility in a cadaver model-satisfying some of the requirements for performance of NOTES procedures.

Bimanual coordination in natural orifice transluminal endoscopic surgery: comparing the conventional dual-channel endoscope, the R-Scope, and a novel direct-drive system

BACKGROUND

The devices used for natural orifice transluminal endoscopic surgery procedures are endoscopes or inspired by endoscopic design, which makes it difficult to accomplish bimanual coordination.

OBJECTIVE

We evaluated 3 operating systems in simulated natural orifice transluminal endoscopic surgery procedures requiring complex bimanual coordination.

DESIGN

Operators were required to perform an identical bimanual task by using 3 operating systems: a dual-channel endoscope (DCE); the R-Scope, which has 2 elevators for independent movement of endoscopic instruments; and the Direct Drive Endoscopic System (DDES), which allows separation of instruments and vision, emulating more of a laparoscopic surgery paradigm.

SETTING

A bench-top simulation was used. Twelve teams were recruited for DCE and R-Scope testing. Twelve individuals participated in the DDES setup. The task included 3 steps: picking up a ring, passing it between endoscopic instruments, and placing it on a designated location.

MAIN OUTCOME MEASUREMENTS

Task performance was evaluated by movement speed and accuracy.

RESULTS

Task performance was significantly faster when using the DDES system (29 +/- 28 seconds) compared with the other operating systems (DCE: 140 +/- 55 seconds, R-Scope: 160 +/- 71 seconds; P < .001). The difference between the DCE and the R-Scope was not significant (P = .370).

CONCLUSION

Designs that separate vision and motion have more degrees of freedom at the tip of the instruments, and an ergonomic user interface provides benefits for bimanual performance compared with more traditional endoscopic designs. With the DDES, a single operator can perform complex endoscopic tasks faster than 2 operators with a DCE or R-Scope.

[Training design and improvement of technical skills in the transvaginal cholecystectomy (NOTES)]

INTRODUCTION

The current surgical scenario of the surgery through natural orifices or <<no-scar surgery>> requires acquiring new technical skills by the surgeon. We introduce the initial experience of the Minimally Invasive Surgery Centre Jesús Usón (MISCJU) in the design and setting-up of a surgical training programme using the the natural orifices approach for the acquisition of surgical skills and abilities, based on the preliminary trials in simulators and a pig model.

MATERIAL AND METHODS

After initial training, using a laparoscopic pelvic-trainer, 7 female pigs, with weights between 35-40 kg, were operated on. The transvaginal approach was completed using a one-channel gastroscope in all the animals. After accessing the abdomen, the abdominal cavity was explored, and the surgery was concluded with the endoscopic cholecystectomy.

RESULTS

Endoscopic cholecystectomy was successfully completed in 6 cases. In one of the animals, the procedure was stopped because of technical problems regarding the endoscope leaning to one end. The average surgical time was 107.14 min (range, 80-150 min). The transvaginal approach enabled the abdominal to be explored and the dissection, ligature and section of the cystic duct and the cystic artery. After cholecystectomy, the gallbladder was extracted through the vagina. After the procedure necropsy did not reveal intra-abdominal lesions or intraoperative complications.

CONCLUSIONS

The pure transvaginal cholecystectomy is a feasible and reproducible procedure in the animal model. A systematized training model, which includes physiopathology knowledge as well as technical knowledge, in order to translate these procedures to the clinical practice in a safe way, is needed.

In vivo microrobots for natural orifice transluminal surgery. Current status and future perspectives

The possibility to operate inside the peritoneal cavity through small holes performed in hollow organs that is presented by Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a major paradigm shift in general surgery. While this new approach seems very appealing from patients' perspectives because it eliminates completely abdominal wall aggression and promises to reduce postoperative pain, it is very challenging for surgeons because of the major constraints imposed by both the mode of access and the limited technology currently available. For this reason NOTES applications at the present time are performed by only a few surgeons and mainly to perform non-complex procedures. While new devices are under development, many of them are trying mainly to simply improve current endoscopic platforms and seem not to offer breakthrough solutions. The numerous challenges introduced by natural orifice approaches require a radical shift in the conception of new technologies in order to make this emerging operative access safe and reproducible. The convergence of several enabling technologies in the field of miniaturization, communication and micro-mechatronics brings the possibility to realize on a large scale the revolutionary concept of miniature in vivo co-operative robots. These robots provide vision and task assistance without the constraints of the entry incision and have been shown in experimental settings to possess many qualities that could be ideal to partner with Natural Orifice Surgery. This article explores the current status of microrobotics as well as presents potential future scenarios of their applications in NOTES.

Endoscopic transcolonic catheter-free pelvic abscess drainage

Natural orifice transluminal endoscopic surgery is a novel therapeutic method in development that uses different routes of surgical approach. The use of various methods, instruments and accessories during this procedure are currently being investigated. A case of appendicitis-related intra-abdominal abscess that was resolved by a transcolonic endoscopic approach using a wide-channel colonoscope with the help of precut and standard sphincterotome without radiological percutaneous drainage is presented.

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.