Reliable gastric closure after natural orifice translumenal endoscopic surgery (NOTES) using a novel automated flexible stapling device

A Look into the Future of Endoscopic Submucosal Dissection and Third Space Endoscopy: The Role for Robotics and Other Innovation

Endoscopic resection has been widely applied especially in endoscopic submucosal dissection and third space endoscopy (TSE). Flexible endoluminal robotics allow performance of endoscopic submucosal dissection with exposure of the submucosal plane for precise dissection using two robotic arms. The introduction of TSE revolutionized the horizon of therapeutic endoscopy to the submucosal space beneath and beyond the mucosa. Advantages of TSE include avoidance of full thickness incision in gastrointestinal tract through the submucosal tunneling for performance of peroral endoscopic myotomy and submucosal tunneling endoscopic resection. In future, robotic-driven devices should be developed to enhance performance of complex endoluminal procedures and TSE.

Endoscopic closure after intraluminal surgery

Endoscopic submucosal dissection is established as a curative endoscopic method for gastrointestinal epithelial neoplasms with a high possibility of complete en bloc resection; however, postoperative adverse events of bleeding and delayed perforation remain. To prevent or minimize them, several techniques for endoscopic mucosal closure have been introduced, such as using endoscopic clips, combined use of hemoclips and supplement devices, and specially designed endoscopic suturing devices. Furthermore, endoscopic full-thickness suturing technique for gastrointestinal wall defect has been developed based on the concept in natural orifice transluminal endoscopic surgery and endoscopic full-thickness resection. Several closure techniques, including over-the-scope clip, threaded bars inserted in a hollow needle, stitches or staplers, and a curved needle and thread are reported. Secure closure of the iatrogenic defect may further expand the range of therapeutic endoscopy. Accumulation of evidence for the efficacy of endoscopic closure and establishment of these techniques are desired.

Endoscopic Suturing, an Essential Enabling Technology for New NOTES Interventions

Natural orifice transluminal endoscopic surgery (NOTES) was developed as a new, minimally invasive approach for various interventions inside the peritoneal cavity. Since the first reports of NOTES animal interventions, various devices have been used for closure of the transluminal entrance site. This article reviews the most commonly used endoscopic closure devices and advantages of the latest generation of endoscopic suturing devices enabling reliable, surgical-quality closure of the full-thickness gastrointestinal wall defects.

Endoscopic full-thickness resection: Current status

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Endoscopic ultrasound-assisted direct peritoneal visualization with a small-caliber scope: A proof of concept study in a swine model

BACKGROUND

Laparoscopic and natural orifice transluminal endoscopic surgery techniques can diagnose peritoneal findings that suggest tumor cell dissemination. However, they have not been incorporated into routine practice, mainly owing to their complexity. To develop a minimally invasive endoscopic technique for the diagnosis of peritoneal findings, we conducted feasibility study using an acute swine model.

MATERIALS AND METHODS

This study involved six domestic pigs. Trans-gastric access to the peritoneal cavity was performed utilizing an endoscopic ultrasound fine needle aspiration (EUS-FNA) technique. After dilation of the needle hole with a biliary dilatation catheter and balloon, a small-caliber scope was inserted into the peritoneal cavity. Peritoneal images were obtained with the scope and a high-resolution microendoscope (HRME). Main outcome measurements were technical feasibility and time needed to access the peritoneal cavity.

RESULTS

Direct visualization of the peritoneum was successful in all six pigs and gained access to the gross appearance of the peritoneal cavity. HRME imaging with topical contrast agent also obtained reasonable quality images representing nuclei of the peritoneal mesothelium. Average operation time from the initiation of EUS-FNA to acquiring peritoneal images was 26.5 min (range 15-40 min). Autopsy found no damage to the adjacent organs, and stomach wall defects were tightly closed with hemostasis clips.

CONCLUSION

EUS-assisted direct peritoneal visualization with small-caliber scope is technically feasible. HRME may assist in the diagnosis of findings on the peritoneum.

A comparison of NOTES transvaginal and laparoscopic cholecystectomy procedures based upon task analysis

BACKGROUND

A virtual reality-based simulator for natural orifice translumenal endoscopic surgery (NOTES) procedures may be used for training and discovery of new tools and procedures. Our previous study (Sankaranarayanan et al. in Surg Endosc 27:1607-1616, 2013) shows that developing such a simulator for the transvaginal cholecystectomy procedure using a rigid endoscope will have the most impact on the field. However, prior to developing such a simulator, a thorough task analysis is necessary to determine the most important phases, tasks, and subtasks of this procedure.

METHODS

19 rigid endoscope transvaginal hybrid NOTES cholecystectomy procedures and 11 traditional laparoscopic procedures have been recorded and de-identified prior to analysis. Hierarchical task analysis was conducted for the rigid endoscope transvaginal NOTES cholecystectomy. A time series analysis was conducted to evaluate the performance of the transvaginal NOTES and laparoscopic cholecystectomy procedures. Finally, a comparison of electrosurgery-based errors was performed by two independent qualified personnel.

RESULTS

The most time-consuming tasks for both laparoscopic and NOTES cholecystectomy are removing areolar and connective tissue surrounding the gallbladder, exposing Calot's triangle, and dissecting the gallbladder off the liver bed with electrosurgery. There is a positive correlation of performance time between the removal of areolar and connective tissue and electrosurgery dissection tasks in NOTES (r = 0.415) and laparoscopic cholecystectomy (r = 0.684) with p < 0.10. During the electrosurgery task, the NOTES procedures had fewer errors related to lack of progress in gallbladder removal. Contrarily, laparoscopic procedures had fewer errors due to the instrument being out of the camera view.

CONCLUSION

A thorough task analysis and video-based quantification of NOTES cholecystectomy has identified the most time-consuming tasks. A comparison of the surgical errors during electrosurgery gallbladder dissection establishes that the NOTES procedure, while still new, is not inferior to the established laparoscopic procedure.

Endoscopic clip closure of gastrointestinal perforations, fistulae, and leaks

Development of endoscopic devices to close perforations has certainly revolutionized endoscopy. Immediate closure of perforations eliminates the need for surgery, which allows us to push the limits of endoscopic surgery from the mucosal plane to deep submucosal layers and eventually transmurally. The present article focuses on endoscopic closure devices, closure techniques, followed by a review of animal and clinical studies on endoscopic closure of perforations.

Gastrojejunostomy by pure natural orifice transluminal endoscopic surgery using a newly designed anastomosing metal stent in a porcine model

BACKGROUND

The accepted palliative treatment for malignant gastric outlet obstruction (GOO) is surgical bypass or placement of self-expandable metal stents. We developed a safe and simple natural orifice transluminal endoscopic surgery (NOTES) technique for gastrojejunostomy using a fully covered, anastomosing metal stent in a porcine model.

METHODS

Under general anesthesia, 11 pigs underwent gastrojejunostomy with a 4 cm length anastomosing metal stent. After gastrotomy formation using a needle knife, the jejunum was drawn into the stomach with alligator forceps. A jejunotomy was then performed in the gastric cavity, which was followed by deployment of an anastomosing metal stent under fluoroscopic guidance. Next, the first portion of the duodenum was resected by an endoscopic linear stapler via laparoscopy, thereby creating the model of GOO. Oral feeding was resumed 24 h after the procedure, and animals were euthanized at 1, 2, and 4 weeks after the operation.

RESULTS

Side-to-side gastrojejunostomy was successfully completed through NOTES in 10/11 animals. Ten pigs stayed healthy until the planned sacrifice. The mean gastrojejunostomy procedure time was 41 min (range 15-94 min). By postmortem examination, anastomoses were still intact without intraperitoneal necrosis or adhesion. Histological examination revealed adequate submucosal apposition in all ten experimental pigs undergoing successful endoscopic gastrojejunostomy.

CONCLUSION

Creating a gastrojejunostomy by NOTES using an anastomosing metal stent seems to be a safe, feasible, durable, and reproducible method for GOO.

NOTES. Study on patients' perspective

Introduction

Rapid development of minimally invasive surgery has led to escalation of the demands placed on health care professionals. Nowadays the patient is the one to choose where and how she/he wants to be operated on. Perioperative and postoperative quality of life is the most common item impacting the patients’ choice. Laparoscopic surgery is undoubtedly advantageous in several applications; however a further improvement of medical services has been introduced: the NOTES technique. This novel surgical approach definitively eliminates the problem of having scars. Though NOTES is still in the clinical trial stage, it might become an alternative for selected procedures soon. At this point it is necessary to define the patients’ expectations and preferences.

Aim

To evaluate patients’ opinions on the four surgical approaches: open, laparoscopic, transvaginal and transgastric.

Material and methods

For this purpose a special questionnaire was designed and one hundred randomly selected women were asked to complete it.

Results

The laparoscopic access was preferable in most aspects, closely followed by the transvaginal access. Open and transgastric approaches were considered as dangerous and disadvantageous.

Conclusions

Currently NOTES is a possible reality of tomorrow for some procedures. The transvaginal access was scored as “attractive”, “cosmetically attractive” and “technologically advanced”, as opposed to the transgastric access. The fact of manipulation in the intimate region requires thorough attention in future NOTES studies. Though the patients currently prefer the laparoscopic approach, this study proves that further development of transvaginal NOTES technology is acceptable and to some extent desired by the patients.

The Performance of Multiple Transgastric Procedures Using the Natural Orifice Transluminal Endoscopic Surgery Technique: Is Pure NOTES Satisfactory?

Background/Aims

Although several groups have demonstrated the usefulness of natural orifice transluminal endoscopic surgery (NOTES), there is still concern about frequent serious adverse events. We performed this study to determine the technical feasibility and safety of pure NOTES with a transgastric approach in a porcine model from the endoscopist's point of view.

Methods

Diagnostic peritoneoscopy, liver biopsy, salpingo-oophorectomy, and Fallopian tube ligation with a transgastric approach using a two-channel therapeutic endoscope were performed in 10 healthy female minipigs. These procedures were performed in two acute models and eight survival models in consecutive order.

Results

The technical success rate was 100% for peritoneoscopy (10/10), liver biopsy (5/5), salpingo-oophorectomy (10/10), and Fallopian tube ligation (10/10). Eight cases of adverse events occurred, including one case of splenic injury, one case of bleeding after liver biopsy, two cases of small bowel adhesion after salpingo-oophorectomy, two cases of hematoma at the salphingo-oophorectomy site, and two cases of partial dehiscence at the gastric closure site. The gastric puncture site was closed with seven to eight hemoclips in four cases and two hemoclips and an endoloop in four cases.

Conclusions

The use of pure NOTES for peritoneoscopy, liver biopsy, salpingo-oophorectomy, and Fallopian tube ligation may be technically feasible, but considerable adverse events can occur during or after the procedure. Further studies utilizing specialized techniques overcome several limitations of pure NOTES are therefore necessary.

NOTES transvaginal hybrid cholecystectomy: the United States human experience

BACKGROUND

"Pure" NOTES and "hybrid" NOTES procedures have gained popularity during the past few years. However, most of these published series have been documented outside the United States.

METHODS

This is a prospective, nonrandomized series of patients. Female subjects who presented to the University of California at San Diego surgery clinic for elective cholecystectomy were offered participation in this study. Patients met the following criteria: aged 18-75 years; diagnosis of gallbladder disease that required cholecystectomy and American Society of Anesthesiology (ASA) class 1. Hybrid NOTES transvaginal technique was used for cholecystectomy.

RESULTS

A total of 27 women underwent hybrid transvaginal NOTES cholecystectomy during a 43-month period. The median age was 40.1 (range 23-63) years. The mean body mass index was 25.2 (range 16.4-34.1). All patients had an ASA I-II classification. The mean operative time was 92 (range 38-165) min. There was no conversion to an open operation. The mean hospital stay was 1.07 (range 1-2) days. Patients were followed for a mean of 3.32 (range 0.06-12.2) months. There were no postoperative complications. No scars were visible on the abdominal wall.

CONCLUSIONS

This study is the largest series of hybrid transvaginal cholecystectomy published in the United States. With our experience, we demonstrate that this technique is safe and clinically viable.

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 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.

A novel flexible endoluminal stapling device for use in NOTES colotomy closure: a feasibility study using an ex vivo porcine model

BACKGROUND

With advances in endoscopic diagnosis of early-stage gastrointestinal pathology, the need to offer minimally invasive treatment is attracting significant interest. It is essential that secure and consistent closure of full-thickness colonic resections and colotomy access be provided in natural orifice translumenal surgery (NOTES). This ex vivo porcine study aimed to evaluate a novel prototype flexible endoscopic stapler device for use in closure of full-thickness colonic defects.

METHODS

A feasibility study using ex vivo porcine colon was undertaken to explore the potential of the prototype stapler to close and seal a colotomy. A standardized linear colotomy was created in 30 colons. The novel flexible endostapler was used to close 20, interrupted hand-sewn sutures to close 5, and a well-validated linear stapler to close 5 of these colotomies. The colons were subsequently subjected to leak pressure testing.

RESULTS

The colotomy closure using the prototype stapler endoluminally required a median time of 280 s. No statistically significant difference in leak pressures between the stapler and the other techniques was described. Although the endostapler without any colotomy was found to have the highest median leak pressures and the interrupted sutures the lowest pressures, no significant difference could be demonstrated (p = 0.52). Furthermore, no significant difference was demonstrated when the closure integrity created by the flexible stapler was compared with that created by the well-validated linear stapler.

CONCLUSION

The results suggest that the flexible endoscopic stapler is an effective device for the safe closure of a visceral defect, which in this feasibility study was equivalent to other well-established techniques. Further studies will focus on in vivo application of the prototype stapling device in the setting of full-thickness colonic resection.

Feasibility of fibrin glue versus endoclips to close the transgastric peritoneal access site in NOTES in a survival porcine study

INTRODUCTION

Safe peritoneal access and gastric closure are the most important concerns in clinical applications of NOTES. Our past study demonstrated usefulness of the submucosal tunnel technique for safe peritoneal access and closure with endoclips. However, such closure is sometimes difficult and time-consuming. This study investigated the feasibility of fibrin glue for submucosal tunnel closure in a NOTES porcine model.

METHODS

In 10 female pigs each weighing 40 kg, transgastric peritoneoscopy was performed through a 60 mm-long submucosal tunnel created using the endoscopic submucosal dissection technique. After transgastric peritoneoscopy for 30 min, the submucosal tunnel was closed with endoclips in five pigs and fibrin glue in five pigs. After a 7 d follow-up period, the pigs were euthanized for post-mortem examination. Outcome measures included (a) technical feasibility of closure with endoclips versus fibrin glue, (b) clinical monitoring for 7 d, (c) follow-up necropsy at 7 d, and (d) histopathologic examination of the peritoneal access site.

RESULTS

Transgastric peritoneoscopy with submucosal tunnel technique was successful in all pigs. Mean time required to close the mucosal incision site with fibrin glue was 1.6 ± 0.5 versus 19 ± 18.7 min with endoclips. All pigs survived well without complications. Necropsy revealed no peritonitis. There were no differences in transgastric peritoneal access sites between endoclips and fibrin glue. Histopathologic examination of the submucosal tunnel demonstrated wound healing with transmural fibrosis. No adverse effects from fibrin glue were noted.

CONCLUSION

Compared with endoclips, the application of fibrin glue is easy and simple in the closure of transgastric peritoneal access in NOTES.

Closure of gastrotomy in natural orifice transluminal endoscopic surgery: a feasibility study using an ex vivo model comparing endoloop with endoclip

BACKGROUND

Closure of access site is one of the key issues that will determine the development of natural orifice transluminal endoscopic surgery. Our study was designed to compare the effectiveness of gastrotomy closure using endoloop and endoclip with hand-sewn closure as a control.

METHODS

Gastrotomy was carried out on 24 ex vivo porcine stomachs and the gastrotomies were randomized to be closed with either hand-sewn, endoloop or endoclip techniques. A 2 cm gastrotomy was created with a needle knife and sphincterotome and the defects closed thereafter. We measured the time to closure of gastrotomy and the pressure at which the closure leaked.

RESULTS

Three endoloops were required for all the closures in the endoloop group. In the endoclip group, the mean (range) number of endoclips used was 10 (8-13). There was no difference in the median closure times between endoloop 28 (16-58) min and endoclip 30 (21-40) min; however, time for hand-sewn closure was much shorter (3-5 min). All stomachs were successfully distended with air without leak at the end of the procedure and none experienced fluid leak. The endoclip closure endured a significantly higher median (range) pressure of 72.5 mmHg (15-80 mmHg) before leaking compared to that of an endoloop 25 mmHg (15-37 mmHg) (P < 0.001). The hand-sewn gastrotomy leaked at pressure of 95 mmHg (75-130 mmHg). The majority of air leaks were from the wound site. In the endoclip group, two leaks were noted at the clip bite site.

CONCLUSION

  In a bench-top model, endoclips seem to be better for gastrotomy closure because of their potential to endure relatively higher pressure without any prolongation of application time. Animal survival studies are needed to explore technical and wound-closure-related problems arising as a result of use of endoclips and endoloops for gastrotomy closure.

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.

Current developments in natural orifices transluminal endoscopic surgery: An evidence-based review

Tremendous advances have been made in recent years addressing the key obstacles to safe performance and introduction of human natural orifice transluminal endoscopic surgery (NOTES). Animal studies have focused on identifying optimal solutions to these obstacles, in particular methods of creating transluminal access, safe closure of the point of access, and development of a multitasking platform with dedicated instruments. Whether the performance data generated from these animal studies can be reproduced in humans has yet to be determined. Reports of human NOTES procedures are emerging, and the possibility of accomplishing human NOTES based on existing technology has been demonstrated. However, dedicated platforms and devices are still lacking to allow for pure NOTES procedures, and whether NOTES can deliver the postulated benefits of earlier recovery and improved cosmesis remains uncertain.

What are the elements of safe gastrotomy closure in NOTES? A systematic review

INTRODUCTION

The safe closure of the gastrotomy needs to be established before natural orifice translumenal endoscopic surgery (NOTES) can be extended to routine clinical practice. As yet no optimum closure method has been identified.

METHODS

A systematic review of the literature on gastrotomy closure modalities for NOTES up until December 2009 was undertaken. An assessment of each closure modality was determined using specified quantitative and qualitative parameters.

RESULTS

There were 46 studies included in this review describing 20 closure techniques. Some robustly designed experimental studies have now been published particularly in relation to the over-the-scope clip system.

CONCLUSION

Current evidence is experimental and therefore limited, but there appears to be some clarification in the direction of the innovative process in this area outlining favorable characteristics of an ideal system. Based on the studies examined in this review, a standardized assessment method is summarized for future in vivo studies, necessary prior to phase 1 trials.

Loop-Anchor Purse-String Closure of Gastrotomy in NOTES® Procedures: Survival Studies in a Porcine Model

Introduction: Transgastric NOTES® procedures remain without a simple method to close the gastrotomy. In four survival swine studies, we have tested a novel gastric closure device: the loop-anchor purse-string (LAPS) closure system. Methods: In four anesthetized pigs, an endoscopic gastrotomy was performed. Four loop anchors were arrayed in a 2-cm square pattern around the gastrotomy. The endoscope was passed into the abdominal cavity, and the gastrotomy was cinched closed. Results: Procedure times ranged from 50-180 minutes. Three pigs survived 14 days. One animal was sacrificed early due to signs of sepsis. Another animal developed fevers and was treated with antibiotics. At necropsy, there were no abscesses, including in the septic animal. Histologic examination revealed evidence of healing in all animals. Discussion: The LAPS system holds promise with early success in an animal model. Future human studies are needed to determine viability as a human visceral closure device.

NOTES: The question for minimal resection and sentinel node in early gastric cancer

Surgical therapy for gastric cancer involves both removal of the cancer lesion and complete lymph node dissection. Natural orifice transluminal endoscopic surgery (NOTES) is considered to represent the next revolution in surgery. Many surgeons and endoscopists believe that NOTES may be a superior alternative for early gastric cancer treatment. Sentinel node (SN) navigation surgery for gastric cancer: Single institution results of SN mapping for early gastric cancer are increasingly being considered acceptable. Furthermore, a major large-scale clinical trial of SN mapping for gastric cancer has recently been completed by The Japan Society of SN Navigation Surgery study group. They reported false negative rate of 7.0% while the sensitivity of metastasis detection based on SN status was 93%. Combination of SN biopsy and NOTES: This concept was first described by Cahill et al who proved the feasibility of lymphatic mapping and SN biopsy by NOTES. Lymphatic channel filling was immediately observable via the intraperitoneal optics. Partial resection of the stomach by hybrid NOTES: Several centers have already reported gastrectomy assisted by NOTES using the transvaginal route. However, the main problem of full-thickness resection of gastric wall remains endoscopic gastric closure. Establishing an endoscopic suturing method would be an important step toward expanding potential indications. NOTES is met with both enthusiasm and skepticism but will gain its own place as human creativity eventually provides solutions to its technical limitations. In the near future, NOTES can evolve the capacity to complement the existing armamentarium for gastric cancer surgery.

Transgastric cholecystectomy: From the laboratory to clinical implementation

After the first report by Kalloo et al on transgastric peritoneoscopy in pigs, it rapidly became apparent that there was no room for an under-evaluated concept and blind adoption of an appealing (r)evolution in minimal access surgery. Systematic experimental work became mandatory before any translation to the clinical setting. Choice and management of the access site, techniques of dissection, exposure, retraction and tissue approximation-sealing were the basics that needed to be evaluated before considering any surgical procedure or study of the relevance of natural orifice transluminal endoscopic surgery (NOTES). After several years of testing in experimental labs, the revolutionary concept of NOTES, is now progressively being experimented on in clinical settings. In this paper the authors analyse the challenges, limitations and solutions to assess how to move from the lab to clinical implementation of transgastric endoscopic cholecystectomy.

A novel double-endoloop technique for natural orifice transluminal endoscopic surgery gastric access site closure

BACKGROUND

Effective and safe access site closure is critical for clinical application of natural orifice transluminal endoscopic surgery.

OBJECTIVE

The current study evaluated a simple novel technique of gastrotomy closure.

DESIGN

Feasibility study with a survival animal model.

SETTING

Animal laboratory.

SUBJECTS

Ten female domestic pigs.

INTERVENTIONS

Endoscopic closure of a gastrotomy incision was evaluated in 10 pigs in a survival study. A standard double-channel endoscope was advanced into the peritoneal cavity through an incision made by a needle-knife and an 18-mm dilation balloon. After peritoneoscopy and salpingectomy, gastric closure was performed by using an endoscopic grasper and sequential application of 2 endoloops. After a follow-up period of 1 to 3 weeks, the pigs were killed for postmortem examination.

MAIN OUTCOME MEASUREMENTS

Feasibility, efficiency, and safety of a novel closure technique.

RESULTS

Correct positioning and delivery of endoloops was achieved in all animals in a median time of 17 minutes (range 13-25 minutes). All animals survived without complications. Postmortem examination demonstrated patent full-thickness gastric closure without any evidence of infection.

LIMITATIONS

Feasibility study with a small number of subjects in a porcine model.

CONCLUSION

Double endoloop technique represents a novel, simple, safe, and efficient means of gastric access site closure in natural orifice transluminal endoscopic surgery.

Single incision approach for splenic diseases: a preliminary report on a series of 8 cases

BACKGROUND

There is a current trend to reduce the invasiveness of minimally invasive procedures, and the single-incision laparoscopic approach (SILS) has been proposed for several intra-abdominal surgical interventions. The spleen poses specific problems for techniques, such as SILS, due to its volume and texture, and little clinical information is available on the topic. We describe our initial experience using SILS for the management of splenic diseases.

METHODS

Between December 2008 and September 2009, we attempted SILS in eight patients: four men and four women with a median age of 44 (range, 26-73) years, and body mass index of 24.5 (range, 18-31). Preoperative diagnosis was malignancy (n = 3), ITP (n = 1), HIV-related hypersplenism (n = 1), spherocytosis (n = 1), and splenic cyst (n = 2). SILS was attempted transumbilically in four cases and through a 15-mm subcostal single incision in the other four. As entry port we used either three trocars (one of 12 mm and two of 5 mm) inserted through the single-site incision or the umbilicus, or a multiport (Triport, Olympus) device. Instrumentation used consisted of curved instruments, a flexible-tip 10-mm scope, and the harmonic scalpel. Visualization of the spleen and standard dissection of attachments was accomplished, and splenectomy was completed by stapling of the splenic hilum. The spleen was extracted through the single-site incision. In two cases, unroofing of a splenic cyst was performed transumbilically.

RESULTS

The SILS procedure was successful in six of the eight patients (75%). Conversion to conventional laparoscopic splenectomy (LS) was required in two patients due to adhesions and spleen size. Median operative time was 97 (range, 60-150) min. There were no postoperative complications, and median stay was 4 (range, 2-5) days. Median spleen weight was 485 (range, 340-590) g.

CONCLUSIONS

SILS access can be safely used for operative visualization, hilum transection, and spleen removal, further reducing parietal wall trauma. The definitive clinical, esthetic, and functional advantages require further analysis.

Single-port access: a feasible alternative to conventional laparoscopic splenectomy

HYPOTHESIS

The laparoscopic approach has become the gold standard for splenectomy despite the fact that the spleen is a solid organ located deep in the splenic fossa. There is currently a trend to reduce the invasiveness of minimally invasive procedures. Transabdominal or transumbilical single-incision laparoscopic (SILS) approaches are an alternative to natural orifice transluminal endoscopic surgery techniques, but no reports of their use have yet been published in relation to the spleen.

AIM

To describe the SILS technique for splenectomy in 2 patients.

MATERIAL AND METHODS

Two patients were approached by SILS, a 26-year-old male diagnosed of autoimmune thrombocytopenia and a 45-year-old male with recurrent Hodgkin disease. In both cases 3 trocars (1 of 12 mm and 2 of 5 mm) were inserted through the umbilicus in one and in a left subcostal in the other, and a curved transanal endoscopic microsurgery instrument, a flexible-tip 10-mm scope, and the UltraCision were introduced. Visualization of the spleen and standard dissection of attachments were feasible, and splenectomy was completed using transumbilicus stapling of the splenic hilum. The spleen was extracted through the umbilical incision, intact in one case and after morcellation in the other.

RESULTS

The postoperative course was uneventful. Both patients had minimal postoperative pain and scarring and were discharged on the second postoperative day.

CONCLUSIONS

SILS access can be safely used for operative visualization, hilum transection, and spleen removal with conventional instrumentation, reducing parietal wall trauma to a minimum. The clinical, esthetic, and functional advantages require further analysis.

Loop-anchor purse-string versus endoscopic clips for gastric closure: a natural orifice transluminal endoscopic surgery comparison study using burst pressures

BACKGROUND

The success of natural orifice surgery depends on a reliable, secure closure of the opening in the gut. Few tests of the integrity of these closures have been published.

OBJECTIVE

To determine whether a gastrotomy can be closed safely and effectively from within the stomach by using looped T-anchors-a novel, endoscopically placed device.

DESIGN

Head-to-head comparison trial of 2 closure methods in 9 explanted porcine stomachs.

SETTING

Animal laboratory.

INTERVENTION

Paired gastrotomies were made in porcine explants. One was closed by using endoscopic clips, and the other was closed by using modified T-anchors in a purse-string fashion.

MAIN OUTCOME MEASUREMENTS

Gastric transmural pressure gradients at bursting of these closures were measured while the explanted stomachs were inflated with a high-pressure insufflator.

RESULTS

The mean burst pressure of the looped T-anchors was 27.3 mm Hg, whereas that of the clip closures was 14 mm Hg. By using 10 mm Hg as a threshold for a "secure" closure, 7 of 9 clip closures failed to meet the threshold value, whereas all 9 of the T-anchor closures met or exceeded the threshold value (P = .0023, 2-tailed Fisher exact test).

LIMITATION

Nonsurvival study.

CONCLUSION

Looped T-anchors provide a secure gastric closure for natural orifice surgery and are superior to endoscopic clips for this purpose.

NOTES-assisted transvaginal splenectomy: the next step in the minimally invasive approach to the spleen

HYPOTHESIS

Natural orifice transluminal endoscopic surgery (NOTES) has marked yet another step forward in less-invasive surgical procedures. Access to solid organs located deep in the left hypochondrium can be difficult using this technique but the transvaginal approach with the patient positioned in full lateral decubitus may be an option.

MATERIAL AND METHODS

We present the case of a 60-year-old woman with a symptomatic splenic polycystic tumor. The procedure was carried out by a multidisciplinary team using a standard flexible videogastroscope and endoscopic instruments. Transvaginal visualization of the spleen and standard dissection of attachments were feasible, and splenectomy was completed using transvaginal stapling of the splenic hilum. The organ was extracted transvaginally.

RESULTS

The postoperative course was uneventful. The patient had minimal postoperative pain and minimal scars, and was discharged on the second postoperative day.

CONCLUSIONS

Transvaginal access can be safely used for operative visualization, hilum transection, and spleen removal with conventional instrumentation, reducing parietal wall trauma to a minimum. The clinical, esthetic, and functional advantages require further analysis.

[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.

Transgastric and Transperineal Natural Orifice Translumenal Endoscopic Surgery (NOTES) in an Appendectomy Test Bed

Introduction. Our purpose was to establish a NOTES appendectomy test bed to evaluate whether the transgastric or transperineal (transvaginal) approach is most efficient. Methods. Using the uterine horns of female pigs as a model for appendectomy, 18 NOTES appendectomies were performed in 2 arms: 9 transgastric and 9 transvaginal. The primary outcome was mean total operative time for each technique excluding access closure. Secondary outcomes were peritoneal access and resection times. Means were compared using Student’s t-test. Results. Transgastric cases were faster than transperineal (46.5 ± 14.5 vs 60.0 ± 20.2 minutes, P = .02). Most of the improvement in transgastric times was due to faster resection (37.9 ± 17.4 vs 51.3 ± 16.5 minutes, P = .03). Neither approach was faster for peritoneal access (8.2 ± 3.4 vs 8.3 ± 4.5 minutes, nonsignificant). A significant learning curve was not demonstrated for the transgastric approach (53.0 vs 40.3 minutes, nonsignificant). A significant learning curve was demonstrated for the transperineal approach (76.0 vs 46.7 minutes, P = .02). Transperineal times improved over the study and approached transgastric; however, the last three transgastric cases were still significantly faster than the last three transperineal (40.3 vs 46.7 minutes, P = .02). No complications occurred in either group. Conclusions. The transgastric as compared with transperineal approach to NOTES appendectomy resulted in improved operative time in this model. The transperineal approach demonstrated a significant learning curve with operative times between techniques converging over time. This NOTES appendectomy test bed is suitable for evaluating NOTES innovations.

Preliminary performance of a flexible cap and catheter-based endoscopic suturing system

BACKGROUND

Translation of natural orifice transluminal endoscopic surgery (NOTES) into clinical applications requires efficient and reliable enterotomy closure.

OBJECTIVE

To evaluate a prototype endoscopic suturing system for enterotomy closure.

DESIGN

This study took place in an ex vivo animal laboratory. Isolated porcine stomachs were contained within a plastic molded abdominal torso. The device specifications included a curved needle, end-cap assembly with a side-mounting wire-actuation channel, a needle-exchange assembly that operates within an endoscopic working channel, and a detachable needle tip attached to suture material.

INTERVENTIONS

Mucosal templates (3-cm circular markings) for targeted suture placement were created along the anterior wall of the stomach (cardia, antrum, and body). Device performance and functionality were studied in 3 ways: suture placement, purse-string closure, and edge-to-edge gastrotomy closure. Interrupted and running stitches were placed with the endoscope straight and retroflexed. Simple leak testing was conducted.

RESULTS

Sutures could accurately be placed at preset templated markings. Creation of a purse-string gastrotomy closure confirmed the capability to place a set of circumferential full-thickness running sutures during a single endoscopic intubation that resulted in a leak-proof closure. Edge-to-edge full-thickness tissue apposition was accomplished, which provided a water-tight closure of an 18-mm gastrotomy. The device worked consistently, without any problems.

CONCLUSIONS

This endoscopic suturing device provided accurate placement of full-thickness sutures during a single intubation and permitted satisfactory tissue apposition. Standardized leak testing is needed for further development and evaluation of new devices. The catheter-driven needle actuator and the transfer-component system were intuitive and universally adaptable to any endoscope. This closure device may advance transluminal therapies by offering a secure, efficient method of hollow viscus closure.

Supplementation of endoscopic submucosal dissection with sentinel node biopsy performed by natural orifice transluminal endoscopic surgery (NOTES) (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is proving to be effective for the resection of selected early gastric and colon cancers. Its application and appropriateness could be extended if a means of determining lymphatic dissemination without recourse to a conventional operation could be provided.

OBJECTIVE

To demonstrate the feasibility of companion sentinel node biopsy (SNB) by natural orifice transluminal endoscopic surgery (NOTES) concurrent with intraluminal ESD in both the sigmoid colon and stomach.

DESIGN

Acute porcine model.

INTERVENTION

Arbitrarily selected mucosal foci were targeted for combined NOTES-SNB and ESD in the sigmoid and stomach of 2 separate anesthetized animals. NOTES peritoneal access was obtained either transgastrically or transvaginally. A second intraluminal endoscope was passed either orally or rectally, as appropriate, to perform submucosal injection for lymphatic mapping under direct vision of the NOTES endoscope. This endoscope then identified the first-order draining (sentinel) nodes and allowed their excisional biopsy. The sigmoid was retracted by magnetic assistance as required, while torque of an intraluminal gastroscope manipulated the stomach. After retrieval of the nodes, 1-cm and 1.5-cm specimens were resected from the sigmoid and stomach, respectively, by conventional ESD. At procedure end, necropsy was performed.

RESULTS

All sentinel nodes were identified, underwent biopsy, and were retrieved intact. ESD was subsequently readily performed without complication. SNB completeness and ESD quality were confirmed postprocedure.

LIMITATIONS

Experimental model with limited sample size.

CONCLUSIONS

Although not yet appropriate for human use, this proposal merits serious consideration as a potential means of augmenting the effectiveness and appropriateness of ESD techniques for GI neoplasia.

Natural orifice translumenal endoscopic surgery (N.O.T.E.S)

Natural orifice translumenal endoscopic surgery (N.O.T.E.S) is a technique that allows access to the peritoneal cavity through natural orifices (oral, rectal, vaginal, vesical) without passing through the anterior abdominal wall. Rapid strides have been made in developing this technique, especially in animal models. Majority of research work in this field is originating from USA, while human clinical trials are being reported from India and Southern America. Morbidly obese patients and ITU patients are two target groups where N.O.T.E.S if implemented, will have the highest potential and bearing. With increasing evidence of safe practice in human models, questions on indications and feasibility of practice need to be addressed by rigorous research, strong evidence and collaboration between surgical centers worldwide.

New developments for endoscopic hollow organ closure in prospective of NOTES

The closure of the gastrotomy in Natural Orifice Endoscopic Surgery (NOTES) is a prerequisite for transgastric endoscopic procedures in the abdominal cavity. Different techniques have been proposed and are under experimental or early clinical investigation. These include the use of conventional endoscopic clips, newly designed clips or T-BARS in different shapes or more complicated devices such as linear endoscopic staplers and septal occluders, originally used for the treatment of cardiac septal defects. We describe here a further alternative of endoscopic organ closure in NOTES, using the OTSC, a novel type of clip attached to the tip of the endoscope. The OTSC clip as a CE-marked device is widely used clinically for various endoscopic procedures, such as the treatment of gastrointestinal bleeding and iatrogenic defects of the digestive tract, e.g. colonic perforations after endoscopic interventions. Now an enlarged version of the OTSC clip can be applied for the closure of transluminal access to the abdominal cavity and is currently being evaluated for use in NOTES. In animal tests we could demonstrate the relatively easy achievement of a full thickness closure of the gastric wall after NOTES in the experimental model. The current data base on OTSC and on other techniques proposed for organ closure after NOTES does not yet allow determining clear advantages or disadvantages of the different options. We believe the hollow organ defect closure now represents the most important issue to decode whether or not we are going to proceed with NOTES. Ongoing surviving animal labs will give us indications on how to proceed.