Principle and history of Natural Orifice Translumenal Endoscopic Surgery (NOTES).

The field of gastrointestinal endoscopy has been witnessing major advances over the last five decades. Developing from flexible endoscopy to endoscopic retrograde cholangiopancreatography (ERCP) in the 1950's and 70's to endoscopic ultrasound in the 80's, endoscopic technology has been transformed from serving purely diagnostic purposes to therapeutic applications. One recent major advance is the notion of using the flexible endoscope, taking it beyond the gastrointestinal lumen into what lies beyond the confines of the gastrointestinal tract. Natural orifice translumenal surgery offers the exciting potential to be safer, less invasive and possibly more cost-effective than the traditional open surgical or laparoscopic approach. The history and principles of natural orifice translumenal endoscopic surgery (NOTES), along with future implications, are outlined in this article.     

Techniques for transgastric access to the peritoneal cavity

Natural orifice translumenal endoscopic surgery (NOTES) is a unique emerging surgical concept expanding flexible endoscopy beyond the gut wall. The methods and technology growing from this concept may minimize trauma from surgical access to the peritoneal cavity by completely eliminating body surface incisions. So far, NOTES surgeries have been reported by modifying laparoscopic surgery. The peroral transgastric route was chosen to access the peritoneal cavity in initial trials because of a potentially lower risk for surrounding organ injury using the anterior wall percutaneous endoscopic gastrostomy-style gastrotomy. This article reviews and describes techniques of transgastric access to the peritoneal cavity used in published animal studies.     

Training for NOTES

The foundation of skills for the performance of natural orifice translumenal endoscopic surgery (NOTES) lies in the training for general surgery (especially laparoscopy) and flexible gastrointestinal endoscopy. Physicians wishing to practice NOTES need to acquire or have both skill sets, or need to partner together to blend complementary capabilities with colleagues. In the future, however, a new cadre of NOTES specialists may emerge who will have developed individual expertise in the full spectrum of NOTES knowledge base requirements. This article highlights a body of knowledge and skills needed to become a NOTES proceduralist and review the current training paradigms for gastrointestinal endoscopists and surgeons.     

The eagle or the snake: platforms for NOTES and radical endoscopic therapy

It has only been about 3 years since natural orifice translumenal endoscopic surgery (NOTES) first began to gather the attention of the medical and surgical community at large. The concepts behind NOTES, however, have been under development for almost a decade. It is important to revisit some basic concepts regarding therapeutic flexible endoscopy and in the process understand the fundamental premises on which a sound technology development program for NOTES should be built. This article provides such a review and emphasizes general principles rather than specific embodiments, which are very much at a nascent stage.     

Submucosal endoscopy with mucosal flap safety valve (SEMF) technique: A safe access method into the peritoneal cavity and mediastinum

Natural orifice translumenal endoscopic surgery (NOTES) is a unique emerging surgical concept expanding flexible endoscopy beyond the gut wall. The methods and technology growing from this concept may minimize trauma from surgical access to the peritoneal cavity by completely eliminating body surface incisions. Our colleagues at the Mayo Clinic have explored, over several years, the concept of using the submucosa as a working space for endoscopic interventions, such as resection of mucosal neoplasias and submucosal tumors, as well as for the acquisition of muscular tissue for etiologic analysis of motility disorders. The submucosal space can also be utilized as a protective tunnel preventing peritoneal soiling by using the free overlying mucosa, as a sealant flap, and permitting a safer offset entry into the peritoneal and thoracic cavities for NOTES. In the SEMF technique, the submucosal space is mechanically created by balloon dissection facilitated by either high‐pressure CO2 gas injection or chemically ‘softening’ the submucosal connective tissues. This article reviews and describes SEMF in detail along with applications involving in vivo porcine models.     

NOTES and anastomosis

The history and development for forming anastomoses using natural orifice translumenal endoscopic surgery (NOTES) techniques is described. Sutured gastrojejunostomy, enteroenteral anastomosis, and ileocolonic anastomoses using rigid and circular staplers passed through the rectum and vaginal wall using a transgastric supervising endoscope using a natural orifice translumenal endoscopic surgery hybrid approach. The staplers for this type of approach have to change. They need to be longer, more flexible, and able to change shape (eg, becoming smaller for introduction and then expanding in the peritoneal cavity). Different methods of introduction over guidewires or in combination with flexible gastroscopes are also needed. There is still a requirement for more ingenuity, persistence, and research if the goal of safer effective formation of anastomoses by less invasive means is to be realized.     

Submucosal endoscopy, a new era of pure natural orifice translumenal endoscopic surgery (NOTES)

Natural orifice translumenal endoscopic surgery (NOTES) involves the intentional perforation of the viscera with an endoscope to access the abdominal cavity and perform an intraabdominal operation. In a brief time period, NOTES has been shown to be feasible in laboratory animal and human studies. Easy access to the peritoneal cavity and complete gastric closure should be secured before NOTES can be recommended as an acceptable alternative in clinical practice. The concept of submucosal endoscopy has been introduced as a solution to overcome these two primary barriers to human NOTES application. Its offset entry/exit access method effectively prevents contamination and allows the rapid closure of the entry site with a simple mucosal apposition. In addition, it could be used as an endoscopic working space for various submucosal conditions. Herein, the detailed procedures, laboratory results and human application of the submucosal endoscopy will be reviewed.     

Endoluminal minirobots for transgastric peritoneoscopy

The performance of surgeries through small incisions or natural orifices minimizes the invasiveness to the patient as compared to open procedures. However, the constraints on visual feedback and dexterity limit the scope of these procedures. Recent robotic technologies attempt to mitigate these constraints for flexible endoscopy and laparoscopy. Much of the current work in flexible endoscopy is in the development of a fully autonomous endoscope capable of providing the surgeon with better control. Advancements in laparoscopic technologies have demonstrated abilities to improve visualization and dexterity through telerobotics and in vivo robotics. The application of new robotic technologies in flexible endoscopy and laparoscopy to natural orifice surgery promises to further benefit the patient by eliminating abdominal incisions, scarring, and the pain associated with these incisions. The safety and feasibility of such robotic technology has been successfully demonstrated for natural orifice transluminal endoscopic surgery (NOTES) in animal models.     

NOTES: past,present and future

Once in a few decades in science or medicine, an idea emerges that is so powerful that it changes forever how we think about that field. Natural Orifices Translumenal Endoscopic Surgery (NOTES) has the potential to break the physical barrier between bodily trauma and surgery. At the dawn of surgery, excellence was associated with big incisions: “big scar ‐ big surgeon”. In the 80s, minimally invasive surgery was born representing one of the greatest surgical evolutions of the 20th century. After Kalloo's first report in 2004 on transgastric peritoneoscopy in a porcine model, the interest in natural orifice transluminal endoscopic surgery (NOTES) has blossomed. Theoretically the same operation performed laparoscopically could be carried out through natural orifices without any abdominal incision avoiding pain and scarring. The lesson learned from the advent of laparoscopic surgery, thought us that we could be witnessing the birth of another surgical revolution. Since 2004 many abdominal procedures that use a NOTES approach have been successfully performed in animal models. However, the initial excitement for NOTES has been somewhat tempered by the reality that a NOTES procedure in human without laparoscopic assistance has not been performed by most groups. Indeed, a major issue is the lack of stable operative platform and flexible instruments that allow retraction and exposure of the organs, such as appendix or gallbladder. Will this issue change the future of NOTES?     

Infection prevention in NOTES

Prevention of infection during natural orifice translumenal endoscopic surgery (NOTES) was identified as one of the most important challenges for translumenal surgery. Does infection prevention during NOTES warrant such attention? This article summarizes the accumulated data about septic complications during translumenal surgery.     

Spectrally encoded fiber-based structured lighting probe for intraoperative 3D imaging

Three dimensional quantification of organ shape and structure during minimally invasive surgery (MIS) could enhance precision by allowing the registration of multi-modal or pre-operative image data (US/MRI/CT) with the live optical image. Structured illumination is one technique to obtain 3D information through the projection of a known pattern onto the tissue, although currently these systems tend to be used only for macroscopic imaging or open procedures rather than in endoscopy. To account for occlusions, where a projected feature may be hidden from view and/or confused with a neighboring point, a flexible multispectral structured illumination probe has been developed that labels each projected point with a specific wavelength using a supercontinuum laser. When imaged by a standard endoscope camera they can then be segmented using their RGB values, and their 3D coordinates calculated after camera calibration. The probe itself is sufficiently small (1.7 mm diameter) to allow it to be used in the biopsy channel of commonly used medical endoscopes. Surgical robots could therefore also employ this technology to solve navigation and visualization problems in MIS, and help to develop advanced surgical procedures such as natural orifice translumenal endoscopic surgery.     

Current status and activity regarding natural orifice translumenal endoscopic surgery (NOTES) in Japan

Natural orifice translumenal endoscopic surgery (NOTES) is a new, minimally invasive technique in the field of gastroenterological surgery. Research on NOTES has rapidly progressed all over the world. A joint committee on NOTES organized by the Japan Society for Endoscopic Surgery (JSES) and the Japan Gastroenterological Endoscopy Society (JGES) established Japan NOTES to encourage the responsible development and safe adoption of NOTES into clinical practice. This paper provides an overview of the current activity in regard to NOTES in Japan.     

EUS-guided NOTES interventions

Entering the peritoneal cavity with the echoendoscope has been avoided because this endoscope is rather rigid and difficult to handle and maneuver in a limited space. Endoscopic ultrasound may be of help, however, to guide natural orifice translumenal endoscopic surgery (NOTES) procedures. This article provides an overview of the potential benefit and the few endoscopic ultrasound-based natural NOTES procedures performed to date.     

NOTES: a surgeon's perspective

Natural orifice transluminal endoscopic surgery (NOTES) is an exciting concept gaining national attention as a novel and minimally invasive approach to gastrointestinal surgery and endoscopy. The hope of combining the talents and experience of surgeons and gastrointestinal endoscopists with emerging technologies has created enthusiasm for developing this approach as a specialty itself. Upon initial review, many procedures seem to naturally lend themselves to this approach and include endoscopic mucosal resection, small tumor excision, and access to the peritoneum. The main question to be answered in this short article is: What is gained and what is lost with NOTES?     

Evolution of laparoscopic surgery: lessons for NOTES

Natural orifice translumenal endoscopic surgery (NOTES) is considered by some to be the next revolution in surgery. To advance into clinical NOTES safely and responsibly, the lessons learned from laparoscopic surgery should be applied to the development of NOTES as much as possible. This novel technique is still in evolution and newly designed instruments and devices should be developed. Industry has a considerable role in research and development and collaboration between clinicians and engineers for this matter is crucial.     

Endoluminal minirobots for transgastric peritoneoscopy.

The performance of surgeries through small incisions or natural orifices minimizes the invasiveness to the patient as compared to open procedures. However, the constraints on visual feedback and dexterity limit the scope of these procedures. Recent robotic technologies attempt to mitigate these constraints for flexible endoscopy and laparoscopy. Much of the current work in flexible endoscopy is in the development of a fully autonomous endoscope capable of providing the surgeon with better control. Advancements in laparoscopic technologies have demonstrated abilities to improve visualization and dexterity through telerobotics and in vivo robotics. The application of new robotic technologies in flexible endoscopy and laparoscopy to natural orifice surgery promises to further benefit the patient by eliminating abdominal incisions, scarring, and the pain associated with these incisions. The safety and feasibility of such robotic technology has been successfully demonstrated for natural orifice transluminal endoscopic surgery (NOTES) in animal models.     

经阴道与经脐单孔腹腔镜在子宫肌瘤手术中的应用比较

目的 对比分析经阴道自然腔道内镜手术（V-NOTES）与经脐单孔腹腔镜在子宫肌瘤切除术中的优缺点。方法 选取2019年1月－2019年10月因子宫前壁单发肌瘤住院行经阴道自然腔道子宫肌瘤切除术的患者23例（观察组）、经脐单孔腹腔镜子宫肌瘤切除术的患者44例（对照组）,对比分析两组患者手术时间、术中出血量、术后肛门排气时间、术后第1天疼痛情况［数字评分法（NRS）］、术后住院时间、术后平均峰值体温和住院费用。结果 观察组术后肛门排气时间（25.52±4.17）h较对照组（32.72±3.06）h短（P < 0.05）,观察组术后第1天NRS疼痛评分（2.65±0.98）分低于对照组（4.50±1.00）分（P < 0.05）;两组患者手术时间、术中出血量、住院时间、术后平均峰值体温和住院费用比较,差异均无统计学意义（P > 0.05）。结论 V-NOTES用于子宫前壁单发肌瘤切除是可行的,患者术后肛门排气时间更短、疼痛程度更轻。     

Combined endoscopy/laparoscopy/percutaneous transhepatic biliary drainage,hybrid techniques in gastrointestinal and biliary diseases

In recent years, a wide range of gastrointestinal endoscopy techniques have been developed, such as endoscopic submucosal dissection (ESD) and endoscopic retrograde cholangiopancreatography (ERCP). Although ESD and ERCP have an important role in gastrointestinal and biliary diseases, each technique has its limitations. Hybrid techniques that combine endoscopic and surgical procedures have emerged that have the advantages of different procedures and negate their limitations at the same time. Laparoscopic endoscopic cooperative surgery and modified laparoscopic endoscopic cooperative surgery combine ESD and laparoscopic techniques to resect submucosal tumors with minimum resection area. Air leak test by intraoperative endoscopy can effectively identify a mechanically insufficient anastomosis and decrease the complication rate. The rendezvous technique that combines percutaneous transhepatic biliary drainage and endoscopy can be performed as a rescue approach for the treatment of biliary obstruction, stenosis and bile duct injuries. For patients with simultaneous presence of stones in the gallbladder and the common bile duct, the laparo-endoscopic rendezvous technique can perform ERCP and laparoscopic cholecystectomy at the same time and reduces the risk of pancreatic injury caused by ERCP. Biliobiliary and bilioenteric anastomosis using magnetic compression anastomosis is another choice for biliary obstruction. The most common used approach to deliver the magnets is by percutaneous-peroral tract. Laparoscopic-assisted ERCP is a safe and highly effective therapy for patients who develop biliary diseases after Roux-en-Y gastric bypass surgery.     

NOTES: the future

The concept of natural orifice translumenal endoscopic surgery (NOTES) has grown in acceptance since the time of its introduction in 2000. Developments in techniques of peritoneal access and closure, surgical techniques, and equipment modification have already been published and intensive research is ongoing. Current and future endoscopists will reap the benefit of this research because many techniques and devices that are developed for NOTES will enhance the ability to perform luminal intervention, including polypectomy, endoluminal hemostasis, and submucosal resection. The authors attempt to predict the future of NOTES by describing potential applications for certain clinical scenarios and conditions.     

NOTES: human experience

Human natural orifice translumenal endoscopic surgery (NOTES) is already being reported from numerous centers, and the results seem promising. There are key issues to be addressed and benefits over traditional safe procedures need to be demonstrated. Interestingly, however, human NOTES seem to be progressing at a fast pace compared with the evolution of surgical procedures or techniques described previously. This article examines the current status of NOTES in humans, the challenges, and the implications on the future of minimal access surgery.