Developing essential tools to enable transgastric surgery

Natural orifice transluminal endoscopic surgery (NOTES) is a largely theoretical but potentially exciting evolution of minimally invasive surgical care. Using technology borrowed from current diagnostic and therapeutic flexible endoscopy, the idea is to replicate current laparoscopic procedures in an “incisionless” manner. It is widely recognized that for NOTES to become a practical reality, many issues need to be resolved, both methodologic and political. One critical element of development will be the design of appropriate instrumentation for NOTES. This is currently happening and involves a complex collaboration between industry and clinicians both to adapt current equipment and to design and create new tools to enable the performance of transluminal procedures. This article describes the current process of such technology development as well as the resulting instrumentation that enables the performance of NOTES. The issues of access and platform stability, laparoscopic-like instruments, and secure tissue approximation are described, and the devices to solve these issues are detailed. Electronic supplementary material Supplementary material is available in the online version of this article at DOI and is accessible for authorized users. Plenary panel presented at the meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), Dallas, 2006.     

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.     

Rapid communication: transvaginal single-port NOTES nephrectomy: initial laboratory experience

BACKGROUND AND PURPOSE: Natural orifice translumenal endoscopic surgery (NOTES) using purpose-built equipment has never been applied to urologic surgery. Herein, we present our initial experience with a trans-vaginal single-port NOTES nephrectomy. METHODS AND RESULTS: An acute experiment was performed in a female farm pig. A single 12-mm trocar was placed in the midline and the TransPort Multi-Lumen Operating Platform (USGI Medical, San Clemente, CA) was passed transvaginally. This flexible device has four working channels and can be locked into position, thereby creating a rigid multitasking platform that allows two-handed tissue manipulation. Dissection was performed using an endoscopic needle knife and a tissue grasper for retraction. Via the 12-mm port, the renal artery and vein were taken separately with a vascular EndoGIA and standard laparoscopic titanium clips, respectively. The kidney was placed in a 10-mm EndoPouch retriever and removed intact via the vagina. The total operative time was 300 minutes. Conclusion: Transvaginal NOTES nephrectomy can be accomplished in a porcine model. Additional testing on survival animals is necessary to validate this approach.     

NOTES über den transösophagealen/transgastrischen Zugang

The new surgical concept of ?natural orifice transluminal endoscopic surgery“ (NOTES) breaks with the old dogma that gastrointestinal flexible endoscopy should be performed exclusively within the gastrointestinal lumen. It guides flexible endoscopy into the peritoneal cavity and to date any access to this was and is a feared complication. NOTES offers a new potential alternative to open surgery as well as laparoscopic surgery. Technical challenges of this new technique include the need for the development of new tools and devices. This is most important for the access to and closure of incisions to the peritoneal and thoracic cavities. The successful incision and closure is a prerequisite for the development of acceptable indications for this new method. In this overview the access and closure techniques currently used as well as some of those which are being considered will be described. Furthermore, possible indications for NOTES will be evaluated and discussed.     

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.     

Endoluminal methods for gastrotomy closure in natural orifice transenteric surgery (NOTES)

Natural orifice transenteric surgery (NOTES) is a new and rapidly evolving concept for intra-abdominal operations that offers the potential for a revolutionary advance in patient care. Conceptually, operations that currently require an open or laparoscopic approach could be performed without incisions in the abdomen, with their concomitant pain and scarring. A recent consensus statement by a joint group of gastrointestinal surgeons and gastroenterologists has identified several technical and technologic hurdles that would need to be overcome before NOTES becomes a clinical reality. One of the most significant requirements identified is the need for a very secure closure of the gastrotomy site that is required for scope passage and specimen removal. Although a rapidly expanding variety of transgastric procedures has been reported, only a few reports address the basic problem of gastrotomy closure. Availability of a safe and simple gastrotomy closure device, however, will be essential for the widespread adoption of the new field of NOTES. Unless new safe and simple devices for endoscopic gastrotomy closure are available and have proven efficacy, NOTES will remain in the hands of a few specialists at centers of excellence because the risk of complications due to insufficient gastrotomy closure will not be acceptable for the surgeon and gastroenterologist in general practice. In this article, we describe three new devices in development or newly on the market that are targeted to advance the safe endoscopic closure of gastrotomy from NOTES.     

Dual-lumen natural orifice translumenal endoscopic surgery (NOTES): a new method for performing a safe anastomosis

Background Bowel anastomosis is one of the most challenging and difficult tasks to perform during natural orifice translumenal endoscopic surgery (NOTES). The difficulty is mainly due to the technical limitations of the endoscopic instruments available. Currently, endoscopic clips, T-bar sutures, or cumbersome suturing devices are used. A dual-lumen NOTES approach can facilitate bowel resection in a pig model by allowing the use of laparoscopic staplers through the rectum. Methods Acute studies were performed on four 40-kg pig models. The dual-lumen NOTES approach was used to perform small bowel resection and anastomosis. An endoscope was passed into the stomach and pushed through the stomach wall into the peritoneal cavity (first lumen), and a 12-mm trocar was placed through the anterior rectal wall, allowing access to the peritoneum (second lumen). Handling of the bowel, resection, and anastomosis were performed using endoscopic instruments through the gastric lumen and laparoscopic instruments through the rectal lumen. The resected small bowel then was removed through the rectum. Results Small bowel resection and anastomosis was successfully completed in all four animals using the dual-lumen NOTES approach. The laparoscopic stapler was used one more time to close the gastrotomy through the rectal port. At autopsy, intact suture lines were noted at the bowel anastomosis and at the stomach, with no evidence of leak from either site. Conclusions Performing a sutured anastomosis in NOTES is complex and time consuming. The use of stapling devices designed for laparoscopic procedures greatly facilitates gastrointestinal tract operations in NOTES. Using both the upper and lower gastrointestinal tract as entry sites for NOTES eliminates some of the current technical limitations of these procedures. Presented at the 2007 society of American Gastrointestinal Endoscopic Surgeons (SAGES) Meeting.     

Single-incision laparoscopic surgery - current status and controversies

Scarless surgery is the Holy Grail of surgery and the very raison d'etre of Minimal Access Surgery was the reduction of scars and thereby pain and suffering of the patients. The work of Muhe and Mouret in the late 80s, paved the way for mainstream laparoscopic procedures and it rapidly became the method of choice for many intra-abdominal procedures. Single-incision laparoscopic surgery is a very exciting new modality in the field of minimal access surgery which works for further reducing the scars of standard laparoscopy and towards scarless surgery. Natural orifice translumenal endoscopic surgery (NOTES) was developed for scarless surgery, but did not gain popularity due to a variety of reasons. NOTES stands for natural orifice translumenal endoscopic surgery, a term coined by a consortium in 2005. NOTES remains a research technique with only a few clinical cases having been reported. The lack of success of NOTES seems to have spurred on the interest in single-incision laparoscopy as an eminently doable technique in the present with minimum visible scarring, rendering a 'scarless' effect. Laparo-endoscopic single-site surgery (LESS) is, a term coined by a multidisciplinary consortium in 2008 for single-incision laparoscopic surgery. These are complementary technologies with similar difficulties of access, lack of triangulation and inadequate instrumentation as of date. LESS seems to offer an advantage to surgeons with its familiar field of view and instruments similar to those used in conventional laparoscopy. LESS remains a evolving special technique used successfully in many a centre, but with a significant way to go before it becomes mainstream. It currently stands between standard laparoscopy and NOTES in the armamentarium of minimal access surgery. This article outlines the development of LESS giving an overview of all the techniques and devices available and likely to be available in the future.     

NOTES. Historia y situación actual de la cirugía endoscópica por orificios naturales en nuestro país

Natural orifice transluminal endoscopic surgery (NOTES), involves a group of new endoscopic approaches to the abdominal cavity, with potential advantages over conventional laparoscopic surgery. It is based on the possibility of performing intra-peritoneal surgical techniques through natural orifices by entering the peritoneal cavity through natural orifices perforating the organ that allows direct access to that cavity (stomach, vagina, rectum, bladder). The possibility of using this same route to access the retroperitoneum and mediastinum has subsequently been postulated.Comments are made on how the technique has been developed, as well as how it has been applied in our country, attempting to give a general view on the risks and benefits of NOTES and the basic requirements to be able to start in this new surgery.     

脐部双套管技术经脐入路腹腔镜胆囊切除术26例

目的探讨脐部双套管技术经脐入路内镜手术（transumbilical endoscopic surgery，TUES）胆囊切除术的可行性。方法26例胆囊疾病（胆囊息肉样病变5例，结石21例）行TUES胆囊切除术。沿脐下缘做横行切口，建立气腹后于切口两侧置入2只5mm操作套管。分别置入5mm腹腔镜和操作器械。于右肋下置入直径2mm抓钳用于协助牵引胆囊。用普通腹腔镜器械和超声刀完成胆囊切除。结果除1例因术中出血中转常规腹腔镜手术外，余25例手术成功。25例成功者手术时间25—50min，平均35min。均未放置引流。无出血、胆漏等并发症发生。除脐部皱褶部位外，基本无可见的腹壁瘢痕。结论双套管技术经脐入路胆囊切除术操作简单、安全，技术上是可行的。同常规腹腔镜手术相比，TUES胆囊切除难度仍较大，在开展TUES手术初期应慎重选择病例。     

Educational and training aspects of new surgical techniques: experience with the endoscopic–laparoscopic interdisciplinary training entity (ELITE) model in training for a natural orifice translumenal endoscopic surgery (NOTES) approach to appendectomy

Background

Natural orifice translumenal endoscopic surgery (NOTES) is a new surgical concept that requires training before it is introduced into clinical practice. The endoscopic–laparoscopic interdisciplinary training entity (ELITE) is a training model for NOTES interventions. The latest research has concentrated on new materials for organs with realistic optical and haptic characteristics and the possibility of high-frequency dissection. This study aimed to assess both the ELITE model in a surgical training course and the construct validity of a newly developed NOTES appendectomy scenario.

Methods

The 70 attendees of the 2010 Practical Course for Visceral Surgery (Warnemuende, Germany) took part in the study and performed a NOTES appendectomy via a transsigmoidal access. The primary end point was the total time required for the appendectomy, including retrieval of the appendix. Subjective evaluation of the model was performed using a questionnaire. Subgroups were analyzed according to laparoscopic and endoscopic experience.

Results

The participants with endoscopic or laparoscopic experience completed the task significantly faster than the inexperienced participants (p = 0.009 and 0.019, respectively). Endoscopic experience was the strongest influencing factor, whereas laparoscopic experience had limited impact on the participants with previous endoscopic experience. As shown by the findings, 87.3% of the participants stated that the ELITE model was suitable for the NOTES training scenario, and 88.7% found the newly developed model anatomically realistic.

Conclusions

This study was able to establish face and construct validity for the ELITE model with a large group of surgeons. The ELITE model seems to be well suited for the training of NOTES as a new surgical technique in an established gastrointestinal surgery skills course.     

Single access laparoscopic surgery: Complementary or alternative to NOTES?

In recent years, single access laparoscopic surgery (SALS) and natural orifice translumenal endoscopic surgery (NOTES) have gained interest from both clinical and industrial point of view, with the increased development of different laparoscopic instruments, production of various access ports, and improvement of operative endoscopes. The main advantages stimulating these two approaches are the cosmetic result, the rapid recovery of the patient, and the reduced need for pain killers. SALS and NOTES are in part complementary and in part alternative techniques. Currently, SALS is much simpler and technically easier than NOTES.     

Natural orifice surgery applied for colorectal diseases

Clinical natural orifice surgery has been applied to abdominal surgery in recent years, mostly using transvaginal and transgastric access. Rectal and transcolonic natural orifice transluminal endoscopic surgery (NOTES) were tested in animal and cadaver models by a few research groups. Despite the potential advantages of transcolonic NOTES for colorectal diseases, it has not yet been clinically applied. The first successful series of human applications of transcolonic NOTES in the literature from the NOTES Research Group in Brazil provide new possibilities in the field in new transrectal procedures for rectal cancer and benign disease. Successful first human reports on Transcolonic NOTES potentially brings new frontiers and applications for minimally invasive surgery. The treatment of colorectal diseases through flexible Perirectal NOTES Access is a promising new approach alongside existing laparoscopic and open surgery to improve patient care.     

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.     

LESSons in minimally invasive urology

Since the introduction of laparoscopic surgery, the promise of lower postoperative morbidity and improved cosmesis has been achieved. LaparoEndoscopic Single Site (LESS) surgery potentially takes this further. Following the first human urological LESS report in 2007, numerous case series have emerged, as well as comparative studies comparing LESS with standard laparoscopy. Technological developments in instrumentation, access and optics devices are overcoming some of the challenges that are raised when operating through a single site. Further advances in the technique have included the incorporation of robotics (R-LESS), which exploit the ergonomic benefits of ex vivo robotic platforms in an attempt to further improve the implementation of LESS procedures. In the future, urologists may be able to benefit from in vivo micro-robots that will allow the manipulation of tissue from internal repositionable platforms. The use of magnetic anchoring and guidance systems (MAGS) might allow the external manoeuvring of intra-corporeal instruments to reduce clashing and facilitate triangulation. However, the final promise in minimally invasive surgery is natural orifice transluminal endoscopic surgery (NOTES), with its scarless technique. It remains to be seen whether NOTES, LESS, or any of these future developments will prove their clinical utility over standard laparoscopic methods.     

Single Laparoscopic Incision Transabdominal (SLIT) Surgery—Adjustable Gastric Banding: A Novel Minimally Invasive Surgical Approach

Natural orifice transluminal endoscopic surgery (NOTES) has become an exciting area of surgical development. However, there are significant limitations to this surgical concept due to the lack of surgical expertise and appropriate flexible instrumentation. An alternative and competing technology to NOTES is single-access surgery. We present a novel surgical technique for placement of an adjustable gastric band utilizing a single laparoscopic incision which was ultimately used for implanting the subcutaneous access port. This new technique is called single laparoscopic incision transabdominal (SLIT) surgery which describes an advanced laparoscopic bariatric operation that can be performed through a tiny slit. The operative time was 55 min. There were no intraoperative complications. The patient did well postoperatively and was discharged on postoperative day 1. There were no postoperative complications at 1-month follow-up. Adjustable gastric banding performed through a single laparoscopic incision is technically feasible. The procedure was performed with mostly existing ports, laparoscopic instrumentations, and visualization platform. Advantages of SLIT surgery compared to conventional laparoscopic surgery will ultimately require further randomized clinical trials.     

Toward scar-free surgery: an analysis of the increasing complexity from laparoscopic surgery to NOTES

Background

NOTES is an emerging technique for performing surgical procedures, such as cholecystectomy. Debate about its real benefit over the traditional laparoscopic technique is on-going. There have been several clinical studies comparing NOTES to conventional laparoscopic surgery. However, no work has been done to compare these techniques from a Human Factors perspective. This study presents a systematic analysis describing and comparing different existing NOTES methods to laparoscopic cholecystectomy.

Methods

Videos of endoscopic/laparoscopic views from fifteen live cholecystectomies were analyzed to conduct a detailed task analysis of the NOTES technique. A hierarchical task analysis of laparoscopic cholecystectomy and several hybrid transvaginal NOTES cholecystectomies was performed and validated by expert surgeons. To identify similarities and differences between these techniques, their hierarchical decomposition trees were compared. Finally, a timeline analysis was conducted to compare the steps and substeps.

Results

At least three variations of the NOTES technique were used for cholecystectomy. Differences between the observed techniques at the substep level of hierarchy and on the instruments being used were found. The timeline analysis showed an increase in time to perform some surgical steps and substeps in NOTES compared to laparoscopic cholecystectomy.

Conclusion

As pure NOTES is extremely difficult given the current state of development in instrumentation design, most surgeons utilize different hybrid methods—combination of endoscopic and laparoscopic instruments/optics. Results of our hierarchical task analysis yielded an identification of three different hybrid methods to perform cholecystectomy with significant variability among them. The varying degrees to which laparoscopic instruments are utilized to assist in NOTES methods appear to introduce different technical issues and additional tasks leading to an increase in the surgical time. The NOTES continuum of invasiveness is proposed here as a classification scheme for these methods, which was used to construct a clear roadmap for training and technology development.

     

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.     

A primer on natural orifice transluminal endoscopic surgery: building a new paradigm

Access to the abdominal cavity is required for diagnostic and therapeutic endeavors for a variety of medical and surgical diseases. Historically, abdominal access has required a formal laparotomy to provide adequate exposure. Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery that eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. During NOTES, commercially available flexible video endoscopes are used to create a controlled transvisceral incision via natural orifice access to enter the peritoneal cavity. Common incision-related complications such as wound infections, incisional hernias, postoperative pain, aesthetic disdain, and adhesions could be minimized or eliminated by NOTES. NOTES has evolved from more than 2 centuries of technological innovations and continued growth in the field of surgical endoscopy. Innovative surgical endoscopists have slowly developed means to surpass the constraints of the gastrointestinal lumen by using a flexible endoscope. The future of surgical endoscopy may be the shared entity of NOTES, which further integrates endoscopy, gastroenterology, and minimally invasive and general surgery. Although the promise of NOTES is electrifying to surgeons and endoscopists, several key issues need to be characterized prior to the incorporation of NOTES into routine practice. This article reviews the status, contemporary body of literature, limitations, and potential future implications accompanying the development of NOTES.     

Transvaginal cholecystectomy without laparoscopic support using prototype flexible endoscopic instruments in a porcine model

Background

Transvaginal cholecystectomy with laparoscopic assistance has been performed safely in humans. The next goal was to develop a natural orifice transluminal endoscopic surgery (NOTES) technique to perform cholecystectomy without laparoscopic instruments using one flexible endoscope and flexible accessories. The aim of the study was to test the feasibility of the procedure in a survival porcine model.

Methods

Cholecystectomies were attempted in five 88–130-lb. pigs with a planned 2-week survival. Prototype flexible instruments (NOTES Toolbox, Ethicon Endo-Surgery, Inc.) were used to aid in access, dissection, and removal of the gallbladder via the transvaginal route.

Results

Cholecystectomy could be completed without abdominal incision using prototype instruments in four out of five pigs. The cystic duct could be exposed with a flexible hook knife and clips applied. The steerable trocar improved stability and the precision of the dissection. The critical view was established in all five pigs. Dissection of the gallbladder off the liver bed was imprecise resulting in gallbladder perforation in all pigs and liver hemorrhage in two. At necropsy, all clips on the cystic duct were secure and no bile leak, bowel injury, or adhesions were present.

Conclusions

NOTES cholecystectomy without laparoscopic support is feasible but challenging using prototype flexible endoscopic devices. A prototype clip applier was effective in controlling the cystic duct. Further improvements in instrument design to ensure precision and safety are needed before flexible devices should be used for pure NOTES procedures in humans.