Natural orifice translumenal endoscopic surgery: critical appraisal of applications in clinical practice

Background  Natural orifice translumenal endoscopic surgery (NOTES), with its focus on eliminating incision-related complications, promises to revolutionize the way surgery is performed. This study aimed to summarize the clinical applications of NOTES for humans, outline the techniques used, and discuss the complications and limitations of current techniques. Methods  A literature search was performed using PubMed and Medline search tools to review the extent and outcomes of human procedures undertaken using the NOTES technique in its pure form or as a hybrid procedure reported until July 2008. The end points were the types of operation performed, the approach and technique used for each operation, and the procedure-related complications and technical limitations. Results  This review considered 16 publications reporting on 49 human subjects. All the studies except three used hybrid NOTES procedures, with varying amounts of transabdominal assistance. Three transvaginal cholecystectomies, one transvaginal appendectomy, and eight transgastric appendectomies have been performed using a pure NOTES technique. To date, 15 NOTES transvaginal cholecystectomies and 10 NOTES appendectomies (8 transgastric and 2 transvaginal) are reported. Other procedures including peritoneoscopy and sigmoid colectomy are described. Three cases of minor morbidity are reported and no mortality. Conclusions  Although initial human results seem encouraging, it is important that this research be conducted in a way that minimizes bad publicity and describes both favorable and adverse outcomes. Robust trials must be conducted at established centers with appropriate experience and institutional board ethical review to allow safe introduction of this novel technique, with adequate and expedient reporting of serious adverse events. The limitations of the current tools and methods are discussed, and suggestions are made for further improvements in the technology to facilitate NOTES operations.     

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.     

Natural orifice translumenal endoscopic surgery (NOTES) for innovation in hepatobiliary and pancreatic surgery: preface

Introduction  Natural orifice translumenal endoscopic surgery (NOTES) has captured the interest of interventional endoscopists and may represent the next stage of evolution of minimally invasive surgery. It provides the potential for performance of incisionless operations. It is gaining momentum both in the animal laboratory and in human case reports. Developments in the field of NOTES have led to the formation of the Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) in 2006. Materials and methods  In this special issue, the current trends in NOTES in the field of hepatobiliary and pancreatic surgery are featured, including NOTES cholecystectomy, hepatectomy splenectomy, pancreatic necrosectomy, and the future of NOTES. In this issue, we discuss the potential benefits of these procedures in hepatobiliary and pancreatic surgery. Conclusion  We have just started the evaluation process for this new technology. The concept of NOTES is becoming established and is enormously advantageous for the patient. Both the surgeon and gastroenterologist should contribute to developing NOTES in making use of their specialties.     

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

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

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.     

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

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

Completely transvaginal NOTES cholecystectomy using magnetically anchored instruments

Introduction Natural orifice translumenal endoscopic surgery (NOTES) is an evolving field and suitable instruments are lacking. The purpose of this study was to perform transvaginal cholecystectomies using instruments incorporated into a magnetic anchoring and guidance system (MAGS). Methods Non-survival procedures were conducted in pigs (n = 4). Through a vaginotomy created under direct vision, a rigid access port was inserted into the peritoneal cavity and used to maintain a CO₂ pneumoperitoneum. MAGS instruments were deployed through the port and held in place on the peritoneal surface using magnetic coupling via an external handheld magnet which was optionally exchanged for an 18ga percutaneous threaded needle anchor; instruments included a tissue retractor (a clip-fixated magnet or flexible graspers) and a cautery dissector. A gastroscope was used for visualization. Results The first two procedures ended prematurely due to instrumentation shortcomings and inadvertent magnetic coupling between instruments; one case required a laparoscopic rescue. Three new forms of instrumentation were developed: (1) a longer access port (50 cm) which provided easier deployment of instruments and suitable reach, (2) a more robust cauterizer with a longer, more rigid, pneumatically deployed tip with better reach and sufficient torque to allow blunt dissection, and (3) a more versatile tissue retractor with bidirectional dual flexible graspers which provided excellent cephalad fundus retraction and inferiolateral infundibulum retraction. With these modifications, 100% of the cholecystectomy was completed in the third and fourth animals using only a NOTES/MAGS approach. Retrieval of the tissue retractor resulted in a rectal injury in the third animal but further procedural modifications resulted in a successful procedure in the fourth animal with no complications. Conclusions While still under development with more refinements needed, completely transvaginal cholecystectomy using MAGS instruments is feasible. By offering triangulation and rigidity, MAGS may facilitate a NOTES approach while alleviating shortcomings of a flexible platform.     

Pure Natural Orifice Translumenal Endoscopic Surgery (NOTES) Transvaginal Nephrectomy

Natural orifice translumenal endoscopic surgery (NOTES) within urology has largely been limited to experimental animal studies and diagnostic procedures in humans. Attempts to complete a pure NOTES transvaginal nephrectomy have thus far been unsuccessful. We report the first clinical experience with pure NOTES transvaginal nephrectomy.     

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.     

经自然腔道内镜技术和单孔腹腔镜技术在结直肠外科手术中的应用

经自然腔道内镜手术（NOTES）和单孔腹腔镜手术（LESS）是当今国际微创外科领域的研究与临床应用热点。NOTES技术尚待进一步的发展．而LESS技术是现阶段最可行的体表“无疤痕”技术。是NOTES技术的过渡阶段。虽然腹腔镜辅助的NOTES结直肠手术和完全的NOTES结直肠手术已经见诸报道．但是该手术目前仍然主要处于动物试验阶段。LESS技术在结直肠手术中的应用已经较为广泛．其可行性已经为较多的文献资料证实．而其是否符合肿瘤根治原则尚需进一步的研究确定。     

Natural Orifice Translumenal Endoscopic Surgery (NOTES) Transvaginal Cholecystectomy in a Morbidly Obese Patient

Transvaginal natural orifice translumenal endoscopic surgery (NOTES) is a new diagnostic and potentially therapeutic method of surgical endoscopy. The first case of NOTES transvaginal cholecystectomy in a morbid obese patient in the literature is described. IRB approval was obtained at the institution for transvaginal NOTES clinical trials. A 58-year-old female patient with cholelithiasis, hypertension, and type II diabetes, and BMI of 35.8 kg/m(2) was submitted to the technique. After transvaginal access, a two-channel gastroscope was introduced into the abdominal cavity along with a laparoscopic trocar. There were 2 umbilical punctures for use of 3 mm laparoscopic equipment. Operative time was 85 min. There was no use of postoperative analgesia, and the patient was discharged on the third postoperative day. Transvaginal NOTES is a feasible alternative method for cholecystectomy in the morbidly obese, although available technology is limited for natural orifice surgery.     

NOTES—third generation surgery. Vain hopes or the reality of tomorrow?

Background Laparoscopic approach has made many procedures less invasive; however, it seems like this is not enough. The newest challenge for the medical environment is applying the scarless surgery in humans. In this article, we review the origin, current state of art, and future of natural orifice transluminal endoscopic surgery (NOTES). The registered base of research in humans is yet scarce; however, the porcine model experimental studies hold a great promise. In NOTES, peritoneal cavity can be easily achieved, and some procedures are feasible through the natural orifices like digestive tract, vagina, or urinary bladder. If safety and advantages of these approaches will be proven beyond question, NOTES procedures are likely to be adapted in humans after overcoming the critical obstacles, like reliable closure methods, indispensable equipment invention, the multidisciplinary specialists training, etc. The aim of this article was to review available literature to provide current state of art in NOTES surgery. Materials and methods Medical databases were searched for animal and human experience with NOTES to give an overview of history, current state of art, and future of this technique. Results NOTES is currently the subject of the intensive research. It seems like this is only the matter of time when a transluminal access to the abdominal or even thoracic cavity will become the reality. Moreover, this will enable the management of some diseases in a possibly minimally invasive pattern, nearly painless and leaving no scar at all.     

经阴道双通道治疗内镜输卵管切除术治疗输卵管妊娠2例报告

目的探讨经阴道内镜下输卵管切除术治疗输卵管妊娠的可行性。方法2009年5月采用经阴道双通道治疗内镜下行输卵管切除术治疗2例输卵管妊娠,经阴道后穹隆置入双通道治疗内镜（OlympusSD-210U-15）,内镜下应用尼龙圈套扎及圈套器电凝电切输卵管及其孕囊。结果2例手术均顺利完成,手术时间51min、62min。住院时间3d、2d。无腹腔感染、出血等并发症发生,血β-hCG分别于术后7d、10d恢复正常,妇检阴道伤口于术后7天愈合。2例均随访90天,复查B超、妇检无异常。结论经阴道内镜下输卵管切除术治疗对无合并症的输卵管妊娠是可行的。     

Changing concepts in the surgery of renal cell carcinoma

Introduction Herein, current developments in open and minimally invasive renal surgery are presented. Materials and methods This also includes considerations on the appropriate indication for the two surgical procedures in small renal tumours, locally advanced disease (>pT2), complicated renal tumours as well as cytoreductive surgical situations. In small renal tumours, similar survival rates have been described for laparoscopic radical and partial nephrectomy. However, even experienced high volume laparoscopic centres report a high learning curve, increased complications and initial technical problems to achieve parenchymal haemostasis and renal ischaemia during nephron-sparing surgery. Surgical management of large (>T2) or complicated tumours is feasible, but long-term oncological outcome is not yet available. Conclusion Promising new developments such as natural orifice translumenal endoscopic surgery (NOTES) might add to our surgical armamentarium for minimally invasive surgery.     

Transgastric endoscopic peritoneoscopy does not require decontamination of the stomach in humans

Introduction  Natural orifice translumenal endoscopic surgery (NOTES) is a rapidly evolving field that provides endoscopic access to the peritoneum via a natural orifice. One important requirement of this technique is the need to minimize the risk of clinically significant peritoneal contamination. We report the bacterial load and contamination of the peritoneal cavity in ten patients who underwent diagnostic transgastric endoscopic peritoneoscopy. Methods  Patients participating in this trial were scheduled to undergo diagnostic laparoscopy for evaluation of presumed pancreatic cancer. Findings at diagnostic laparoscopy were compared with those of diagnostic transgastric endoscopic peritoneoscopy, using an orally placed gastroscope, blinding the endoscopist to the laparoscopic findings. We performed no gastric decontamination. Diagnostic findings, operative times, and clinical course were recorded. Gastroscope and peritoneal fluid aspirates were obtained prior to and after the gastrotomy. Each sample was sent for bacterial colony counts, culture, and identification of species. Results  Ten patients, with an average age of 63.7 years, have completed the protocol. All patients underwent diagnostic laparoscopy followed by successful transgastric access and diagnostic peritoneoscopy. The average time for laparoscopy was 7.2 min, compared with 18 min for transgastric instrumentation. Bacterial sampling was obtained in all ten patients. The average number of colony-forming units (CFU) in the gastroscope aspirate was 132.1 CFU/ml, peritoneal aspirates prior to creation of a gastrotomy showed 160.4 CFU/ml, and peritoneal sampling after gastrotomy had an average of 642.1 CFU/ml. There was no contamination of the peritoneal cavity with species isolated from the gastroscope aspirate. No infectious complications or leaks were noted at 30-day follow-up. Conclusions  There was no clinically significant contamination of the peritoneal cavity from the gastroscope after transgastric endoscopic instrumentation in humans. Transgastric instrumentation does contaminate the abdominal cavity but, the pathogens do not mount a clinically significant response in terms of either the species or the bacterial load.     

Current status and future perspectives in laparoendoscopic single‐site and natural orifice transluminal endoscopic urological surgery

Objective of this study is to provide an evidence‐based analysis of the current status and future perspectives of scarless urological surgery. A PubMed search has been performed for all relevant urological literature regarding natural orifice transluminal endoscopic surgery (NOTES) and laparoendoscopic single‐site surgery (LESS). In addition, experience with LESS and NOTES at our own institution has been considered. All clinical and investigative reports for LESS and NOTES procedures in the urological literature have been considered. A wide variety of clinical procedures in urology have been succesfully completed by using LESS techniques. Thus far, experience with NOTES has largely been investigational, although early clinical reports are emerging. Further development of instrumentation and platforms is necessary for both techniques to become more widely adopted throughout the urological community.     

Transgastric instrumentation and bacterial contamination of the peritoneal cavity

Introduction Natural orifice transluminal endoscopic surgery (NOTES) is a rapidly evolving technique providing access to the peritoneum utilizing an endoscope via a natural orifice. One of the most significant requirements of this technique is the need to minimize the risk of clinically significant peritoneal contamination. We report the bacterial load and contamination of the peritoneal cavity in patients requiring a gastrotomy Roux-en-Y gastric bypass (LSRYGB). Methods We prospectively studied 50 patients undergoing a gastrotomy with creation of a gastrojejunostomy during LSRYGB. We recorded the patient’s proton-pump inhibitor (PPI) utilization preoperatively and sampled gastric contents without lavage. We also sampled peritoneal fluid prior to and after gastrotomy, noting the length of time the gastrotomy was open to the peritoneum. Each of the three samples was sent for bacterial colony counts, and culture with identification of species. Results Fifty patients underwent LSRYGB with a mean operative time of 93 min. The gastrotomy was open to the peritoneal cavity for an average of 18 min. Seventeen of 50 patients were on PPIs preoperatively, resulting in a significant difference in postgastrostomy peritoneal bacterial counts. The average number of colony-forming units (CFU) of the gastric aspirate was 22,303 CFU/ml. Peritoneal aspirates obtained for examination prior to creation of a gastrotomy showed no CFUs in 44 of 50 patients. Peritoneal sampling after gastrotomy showed contamination of the abdomen with an average of 1102 CFU/ml. There was no correlation between the bacterial load in the stomach and peritoneal load after gastrotomy. No infectious complications or leaks developed. One complication of rhabdomyolysis in a patient with no peritoneal bacterial contamination developed. Conclusions Transgastric instrumentation does contaminate the abdominal cavity but pathogens are clinically insignificant due to species or bacterial load. Patients on PPIs do have an increased bacterial load in the gastric aspirate, with no clinical significant infection.     

NOTES-Natural orifice transluminal endoscopic surgery: Why not?

Since natural orifice transluminal endoscopic surgery (NOTES) was first described by Anthony Kalloo, it has attracted tremendous interest from surgeons and gastroenterologist all around the world. This special issue of the World Journal of Gastrointestinal Surgery explores the current possibilities and future potential of the most disruptive revolution in the field of surgery represented by the NOTES approach. In the future, new technologies developed for this approach and deeper insight into several gastrointestinal diseases will lead to the design of completely new interventional procedures and change the way we will operate, bringing us to the previously unimaginable goal of "no scar surgery".     

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

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