Perioperative inflammatory response in natural orifice translumenal endoscopic surgery

Background

Natural orifice translumenal endoscopic surgery (NOTES) could offer multiple advantages compared with the laparoscopic approach. One such potential advantage, not yet proven, is the inferior inflammatory response, which translates into less significant operative stress. This study aimed to compare the immuno-inflammatory response between transgastric NOTES and laparoscopy for simple surgical procedures (oophorectomy) with reference to the cytokine levels.

Methods

For this study, 20 female pigs were randomly assigned to either NOTES or laparoscopic oophorectomy. Seven animals were used as a control group and received only general anesthesia, with no other procedure performed. Blood samples were obtained before surgery, 1 h after the start of the procedure, and at the end of the intervention. The serum levels of IL1β and IL6 were determined using a porcine enzyme-linked immunosorbent assay (ELISA) kit. The mean operative time, intraoperative incidents, and postoperative complications were recorded. On postoperative day 14, the animals were killed, and gastric leak tests were performed.

Results

Both the NOTES and laparoscopic procedures were successfully completed. No gastric leaks were observed during necropsy. The transgastric oophorectomy required a significantly longer time to perform than the laparoscopic surgery. Compared with the NOTES procedures, laparoscopic oophorectomy resulted in significantly higher levels of interleukin-1β (IL1β) (42.34 ± 5.26 ng/ml with NOTES vs 46.93 ± 4.79 ng/ml with laparoscopy; p = 0.028) and IL6 (66.95 ± 7.29 ng/ml with NOTES vs 71.75 ± 4.76 ng/ml with laparoscopy, p = 0.049) during the postoperative phase. No statistical difference was detected between the pre- and postoperative cytokine levels in the NOTES group.

Conclusion

The study findings suggest that pure transgastric endoscopic surgery is a safe approach resulting in less perioperative inflammatory response than laparoscopy in the early postoperative phase.     

Current status and prerequisites for natural orifice translumenal endoscopic surgery (NOTES)

Natural orifice translumenal endoscopic surgery (NOTES) is a sophisticated form of endoscopic surgery whose use has recently spread rapidly around the world. Although hundreds of reports of animal studies and clinical cases about NOTES have been published since 2004, NOTES is still in the experimental phase. The formation of an iatrogenic incision in the lumenal wall of intraperitoneal organs is a major disadvantage of NOTES. No reliable technique for complete closure has yet been established, and this problem must be resolved before NOTES can be adopted as a routine clinical practice. Several devices for the closure of lumenal incisions in the stomach or colorectum have been developed, and their safety and usefulness have been examined in animal studies and clinical cases. Kyushu University has been involved in furthering the adoption of NOTES as a routine clinical practice, and the Kyushu University Training Center for Minimally Invasive Surgery holds training sessions on endoscopic surgical techniques for surgeons from all over Japan. Studies to develop a navigation system and robotic technology for use with NOTES are also in progress at Kyushu University. The further development of endoscopy-related technologies and equipment, such as robotic technology, is therefore essential to allow the safe, widespread adoption of pure NOTES.     

Adrenalectomy using natural orifice translumenal endoscopic surgery (NOTES): A transvaginal retroperitoneal approach

Background  Endoscopic adrenalectomy currently is performed using either a retroperitoneal or transperitoneal approach. The retroperitoneal approach is ideal for patients with small lesions who have undergone previous intraabdominal surgery. This study aimed to explore transvaginal retroperitoneal right and left adrenalectomies in porcine and cadaver models. Methods  Right and left adrenalectomies were performed for two female pigs. With the pig supine under general anaesthesia, the retroperitoneal space was entered with a double-channel endoscope (Storz) through a posterior colpotomy. A retroperitoneal tunnel was fashioned using blunt dissection with the assistance of low carbon dioxide insufflation up to the inferior pole of the kidney. Dissection of the upper renal pole allowed access to the adrenal gland. Using blunt dissection, a plane was created between the aorta on the left and the adrenal gland and inferior vena cava on the right. The left main middle vascular pedicle was identified and taken between clips, whereas an endoloop was used on the right side. The specimen was retrieved intact with a polypectomy snare. The same access then was reproduced with two female cadavers. Results  Transvaginal retroperitoneal adrenalectomies were successfully accomplished with a transvaginal approach using natural orifice translumenal endoscopic surgery (NOTES). The operative time was 70 min, and there was no injury to the retroperitoneal structures. The access was effectively reproduced in the cadaver model, with prompt identification of the retroperitoneal anatomic landmarks. Conclusion  Transvaginal retroperitoneal NOTES adrenalectomy is feasible in the porcine model. It reaches the adrenal proper anatomic plane with no need for dissection or retraction of the surrounding organs. This technique might be especially valuable for patients with multiple previous abdominal operations and obese patients in that allows direct access to the adrenal gland and minimizes the cardiovascular and pulmonary risk related to carbon dioxide pneumoperitoneum. Although the operation was successfully validated with cadavers, further experiments and better tools are needed before NOTES transvaginal retroperitoneal access is considered for humans. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Feasibility of radical sigmoid colectomy performed as natural orifice translumenal endoscopic surgery (NOTES) using transanal endoscopic microsurgery

Background Natural orifice translumenal endoscopic surgery (NOTES), a recent development in the field of minimally invasive surgery, may offer advantages over open and laparoscopic surgery. Most investigations to date have focused on small end-organ resections, and none have described en bloc regional lymphadenectomy. This study aimed to describe a method of anal transcolonic sigmoid colon resection. Methods A fresh frozen then thawed cadaver model was used. Three male human cadavers were subjected to transanal sigmoid colon mobilization, high vascular ligation, en bloc lymphadenectomy, and stapled end-to-end anastomosis performed by a single operator using transanal endoscopic microsurgery instrumentation. Results The findings showed that NOTES sigmoid colon resection with en bloc lymphadenectomy and primary anastomosis can be performed successfully. The critical steps of the procedure were (1) luminal suture occlusion of the sigmoid colon, (2) transrectal bowel division, (3) entry through the mesorectum into the presacral space, (4) en bloc mobilization of the sigmoid colon mesentery off of the retroperitoneum, (5) high ligation of the superior hemorrhoidal artery, (6) transanal delivery of the intact sigmoid colon specimen, (7) extracorporeal division of the colon, and (8) creation of a stapled end-to-end colorectal anastomosis. Postprocedure laparotomy confirmed adequate lymphadenectomy and anastomosis with no untoward events. Conclusions It is possible to complete the critical steps of a NOTES sigmoid resection, en bloc lymphadenectomy, primary anastomosis, and retrieval of an intact specimen without any incisions using transanal endoscopic microsurgery instrumentation.     

Natural orifice translumenal endoscopic surgery (NOTES) in urology: initial experience

BACKGROUND AND PURPOSE: For years, urologists have been champions of surgery performed through natural body openings. The next frontier is intraperitoneal or retroperitoneal surgery performed via natural body openings. We reviewed the initial experience with natural orifice translumenal endoscopic surgery (NOTES) in urology. METHODS: The first experimental application of NOTES was published in 2002 when transvaginal nephrectomy was performed in the porcine model. Confirmatory experimental studies using the gastrointestinal tract for NOTES were first published in 2004. The bladder was first experimentally evaluated as a portal for NOTES in 2006. Urologists have developed and evaluated novel magnetic anchoring systems and operative platforms for NOTES. To date, clinical application of NOTES in urology is limited to transvesical peritoneoscopy. RESULTS: Analysis of the literature suggests that technologic, anatomic, physiologic, ethical, and philosophical questions must be answered before NOTES will be widely introduced or justified clinically. The premise that NOTES will be associated with a better recovery and fewer postoperative risks also remains to be evaluated. CONCLUSIONS: Largely in experimental models, urologists have show feasibility of NOTES. Ongoing evaluation and the introduction of new technologies are required for the field to advance. In addition, NOTES should be carefully embraced only after detailed evaluations prove a measured benefit in comparison to established minimally invasive techniques.     

A novel percutaneous insufflating guidewire system for transgastric natural orifice translumenal endoscopic surgery (NOTES) (with video)

Background

A modified percutaneous endoscopic gastrostomy (PEG) technique has been widely used as a safe alternative for gaining peritoneal access in transgastric (TG) natural orifice translumenal endoscopic surgery (NOTES). The authors developed a novel insufflating guidewire (IGW) system, which further maximizes the safety of the modified PEG technique by preparation of a preliminary pneumoperitoneum (PP) before TG route creation. This study aimed to assess the feasibility and safety of the modified PEG technique under PP using the IGW system.

Methods

The IGW system was evaluated in porcine models (n = 5). The process of PP creation was monitored with either laparoscopy or real-time magnetic resonance imaging. The times required to create PP and to establish the TG route were prospectively registered. The animals were killed at the end of each experiment for evaluation of any injuries to adjacent organs.

Results

Preliminary pneumoperitoneum was successfully created in all the animals (median procedural time, 240 s) in rapid and highly reproducible fashion. The creation of the TG route also was quick and straightforward (median procedural time, 100 s). No injuries to the adjacent organs were noted at necropsy.

Conclusions

The establishment of the TG route under PP is feasible and safe with the authors’ newly developed IGW system. The device seems to be advantageous because the entire session is endoscopically controlled. The device may become one of the useful alternatives for adopting TG NOTES in daily practice. Further assessment with human subjects is necessary to make this system practical and universal.     

Directed submucosal tunneling permits in-line endoscope positioning for transgastric natural orifice translumenal endoscopic surgery (NOTES)

Background  

Submucosal dissection is demonstrated to be a technically feasible, safe means of obtaining peroral transgastric peritoneal access for natural orifice translumenal endoscopic surgery (NOTES). The authors hypothesized that their previously described self-approximating translumenal access technique (STAT) could be used to create directed gastric submucosal tunnels permitting in-line endoscope positioning with predetermined abdominal locations that might otherwise be difficult to access.     

Natural orifice translumenal endoscopic surgery (NOTES) renal cryoablation in a porcine model

OBJECTIVE

To present our laboratory experience with natural orifice translumenal endoscopic surgery (NOTES) renal cryoablation.

MATERIALS AND METHODS

In two female farm pigs, we performed four procedures of NOTES renal cryoablation. In each pig, NOTES was performed through a transgastric approach and a transvaginal approach for each kidney, respectively. The pig was placed in the flank position and pneumoperitoneum obtained using a transabdominal Veress needle. In the first pig, we started with the left kidney with a transgastric approach: a dual‐channel video gastroscope (Olympus, Tokyo, Japan) was used, the stomach wall was punctured using a needle‐knife, a guidewire was passed into the abdominal cavity and the access dilated using a controlled radial expansion balloon. The bowel was mobilized medially and the Gerota’s fascia overlying the upper pole was dissected. Under direct endoscopic vision, a cryoablation probe was introduced percutaneously into the anterior upper pole of the kidney. The pig was then flipped to the right flank position and a transvaginal approach was used: the gastroscope was introduced through the posterior fornix of the vagina. For the second pig, we performed initially a transgastric right‐side cryoablation then a transvaginal left‐side cryoablation as described for the first pig.

RESULTS

All four procedures were performed successfully, with no intraoperative complications. No additional laparoscopic ports or open conversions were necessary. The vision of the kidney and the ice‐ball was adequate for all cases. The mean operative duration was 83 min. Stomach closure was tested watertight, and there were no abdominal or pelvic injuries found at autopsy.

CONCLUSIONS

NOTES can provide adequate minimal surgical dissection for safe and effective percutaneous renal cryoablation under direct videoscopic monitoring at kidney locations otherwise not accessible percutaneously. Both transgastric and transvaginal approaches can be used effectively for renal cryoablation providing a minimally invasive scar‐less surgery.     

Natural orifice translumenal endoscopic surgery (NOTES): safe implementation through technological innovation

BACKGROUND: NOTES is advancing at a rapid pace with large registries of human applications and increasing evidence to support safety and efficacy. We have however arrived at a stage in the development of the technique where many conceptual applications are not supported by available technology to ensure safe implementation. METHODS: The data presented in this editorial are based on the views of the authors and reviews of the literature which have been conducted using PubMed, a search tool of the National Library of Medicine and the national institute of Health, including the MEDLINE database and the Cochrane library until the 1st of February 2011. RESULTS: This editorial reviews the technological challenges that must be overcome and novel solutions are discussed. CONCLUSIONS: For NOTES to realise its full potential, surgeons have to wait for technology to catch up with ideological innovation before embarking on more complex procedures than the hybrid transvaginal feasibility studies currently taking place.     

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

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

Natural orifice translumenal endoscopic surgery (NOTES) partial nephrectomy in a porcine model

Background  

This study aimed to evaluate the feasibility of natural orifice translumenal endoscopic surgery (NOTES) transgastric partial nephrectomy without hilar clamping in a porcine model.     

Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy

Enthusiasm for natural orifice transluminal endoscopic surgery (NOTES) has been partly tempered by the reality that most NOTES procedures to date have been laparoscopically assisted. After safely performing transvaginal cholecystectomy in an IACUC-approved porcine model, the authors embarked on an institution review board (IRB)-approved protocol for ultimate performance of pure NOTES cholecystectomy in humans. They describe their experience performing a true NOTES transvaginal cholecystectomy after safely accomplishing three laparoscopically assisted or hybrid procedures in humans. One of the patients was a 35-year-old woman presenting with symptoms of biliary colic. Ultrasound confirmed gallstones, and her liver enzymes were normal. Pneumoperitoneum to 15 mmHg was obtained via a transvaginal trocar placed through a colpotomy made under direct vision. A double-channel endoscope then was advanced into the abdomen. To overcome the retracting limitations of currently available endoscopes, the authors used an extra-long 5-mm articulating retractor placed into the abdomen via a separate colpotomy made under direct vision using the flexible endoscope in a retroflexed position. Endoscopically placed clips were used for control of both the cystic duct and the artery. These techniques obviated the need for any transabdominally placed instruments or needles. This patient was the first to undergo a completely NOTES cholecystectomy at the authors’ institution, and to their knowledge, in the United States. She was discharged on the day of surgery and at this writing has not experienced any complication after 1 month of follow-up evaluation. Performance of NOTES transvaginal cholecystectomy without aid of laparoscopic or needleoscopic instruments is feasible and safe for humans. Additional experience with this technique are required before studies comparing it with standard laparoscopy and hybrid techniques are appropriate.     

Colonic sterilization for natural orifice translumenal endoscopic surgery (NOTES) procedures: a comparison of two decontamination protocols

Background  This study aimed to evaluate the effect of two different sterilization protocols on the bacterial counts in the swine colon as preparation for natural orifice translumenal endoscopic surgery (NOTES) surgery. Methods  In this study, 16 swine were randomized to two different colonic sterilization protocols: low colonic irrigation using 300 ml of a 1:1 dilution of 10% povidone–iodine (Betadine) with sterile saline, followed by 1 g of cefoxitin dissolved in 300 ml of saline or two consecutive 300-ml irrigations using a quaternary ammonium antimicrobial agent (Onamer M). Colonic cultures were taken before colonic cleansing after a decontamination protocol and after completion of the NOTES procedure. The Invitrogen live/dead bacterial viability kit was used to assess for change in the bacterial load. A qualitative culture of peritoneal fluid was obtained at the end of the NOTES procedure. Colon mucosal biopsies obtained immediately after the sterilization procedure and at the 2-week necropsy point were evaluated for mucosal changes. Results  Protocol 1 resulted in an average 93% decrease in live colonic bacteria versus 90% with protocol 2 (nonsignificant difference). After a NOTES procedure, group 1 had a 62% increase in live bacteria and group 2 had a 31% increase (nonsignificant difference). Peritoneal cultures also were obtained. Bacteria were isolated from the peritoneal fluid of all the animals, and two or more species were isolated from 75% of the animals. There was no evidence of peritoneal infection at necropsy. Reactive epithelial changes and mild inflammation were the only pathologic abnormalities. No changes were noted at histologic evaluation of colonic mucosa after 2 weeks, demonstrating that these were temporary changes. Conclusion  Colonic irrigation with Betadine and antibiotics are as effective for bacterial decontamination of the swine colon as a quaternary ammonium compound. The results of this study support the use of either protocol. Despite thorough decontamination, peritoneal contamination occurs. The significance of this for humans is unknown. Presented at the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) 2008.     

Patient attitudes and expectations regarding natural orifice translumenal endoscopic surgery

Background  Natural orifice translumenal endoscopic surgery (NOTES) has theoretical patient advantages. Because public attitude toward NOTES will influence its adoption, this study aimed to assess patients’ opinions regarding the NOTES procedure. Methods  For this study, 192 patients were surveyed. Both NOTES and laparoscopic surgery (LS) are described together with an example case. Presurgical patients rated the importance of various aspects of surgical procedures and their preference for cholecystectomy via NOTES or LS. Results  Complication risks, recovery time, and postoperative pain were considered more important than cosmesis, cost, length of hospital stay, or anesthesia type (p < 0.001). In the self-reports, 56% of the respondents preferred NOTES for their cholecystectomy and 44% chose LS. The patients perceived NOTES as having less pain, cost, risk of complications, and recovery time but requiring more surgical skill than open surgery or LS (p < 0.04). College-educated patients were more likely to choose NOTES, whereas patients 70 years of age or older and those who had undergone previous flexible endoscopy were less likely to select NOTES (p < 0.04). Although 80% of the patients choosing NOTES still preferred it even if it carried a slightly greater risk than LS, their willingness to choose NOTES decreased as complications, cost, and hospital distance increased and as surgeon experience decreased (p < 0.001). This study had a limitation in that the survey population was from surgery clinics. Conclusion  A majority of the patients surveyed (56%) would choose NOTES for their cholecystectomy. The deciding characteristics of the patients were more education, youth, and no previous flexible endoscopy. Procedure-related risks, pain, and recovery time were more important than cosmesis, cost, length of hospital stay, and anesthesia type in the choice of a surgical approach. Patients were less willing to accept NOTES as risks and costs increased and as surgeon experience and availability decreased.     

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

Background  Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of the gastrotomy incision in a porcine model. Methods  A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure, the animals were killed for a study of closure adequacy. Results  Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler loads with a cutting blade. In the three remaining animals (pigs 2–4), we were able to achieve a full-thickness closure of the gastric wall incision without any complications. Conclusions  The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal interventions. Presented in part at the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Annual Meeting, Las Vegas, Nevada, April 2007.     

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.     

Transrectal robotic natural orifice translumenal endoscopic surgery (NOTES) applied to intestinal anastomosis in a porcine intestine model

Background

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive operation using devices such as flexible endoscopes and linear or circular staplers. Nevertheless, hand-sewn anastomosis in NOTES remains challenging. This study aimed to investigate the feasibility of transrectal robotic NOTES requiring intracorporeal small intestinal anastomosis and closure of the rectal anterior wall incision in a relevant human model.

Methods

The authors developed a flexible rectal proctoscope with a diameter of 43 mm for transrectal robotic NOTES. Small intestinal anastomosis was performed in a porcine intestinal transrectal NOTES model using two robotic arms and a camera inserted through the proctoscope and a rectal anterior wall incision. The quality of transrectal small intestinal anastomosis using the da Vinci surgical system (transrectal robotic NOTES group) was compared with that of transabdominal anastomosis using the da Vinci surgical system (transabdominal robot-assisted surgery group) and transrectal anastomosis using traditional transanal endoscopic microsurgery (TEM) instruments (TEM NOTES group). The quality of transrectal rectal anterior wall suturing in the transrectal robotic NOTES group was compared with that of the TEM NOTES group and the open surgical instruments group (open group).

Results

Robotic intracorporeal suturing was performed successfully in the porcine intestine model. During small intestinal anastomosis, burst pressure in the transrectal robotic NOTES group (67.7 ± 29.3 mmHg) was similar to that in the transabdominal robot-assisted surgery group (73.3 ± 18.2 mmHg) but significantly higher than in the TEM NOTES group (20.3 ± 24.0 mmHg; p < 0.01). During rectal anterior wall suturing, the burst pressure did not differ significantly between the transrectal robotic NOTES group (149.9 ± 81.1 mmHg) and the open group (195.0 ± 60.5 mmHg).

Conclusions

The preliminary safety and efficacy of transrectal robotic NOTES was established. Further studies are required to determine the practical feasibility of this procedure.     

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.