Natural orifice translumenal endoscopic surgery applications in clinical practice

Comparing outcomes of ovarian cystectomy by vaginal natural orifice transluminal endoscopic surgery versus laparoendoscopic single-site surgery: A retrospective cohort study

BACKGROUND

We aimed to compare the outcomes of ovarian cystectomy (OC) performed by vaginal natural orifice transluminal endoscopic surgery (vNOTES) vs transumbilical laparoendoscopic single-site surgery (LESS).

METHODS

We retrospectively analyzed the data of patients in our hospital who underwent OC either by vNOTES or LESS between January 2015 and September 2021. Demographic data were collected. The primary outcome was the conversion rate. The secondary outcomes were the duration of surgery, length of hospital stay, estimated blood loss, maximum body temperature within 48 hours after operation, and duration of maximum body temperature (hours), among others. Statistical analysis was done using the SPSS software.

RESULTS

Exactly 284 patients were screened. The vNOTES and LESS groups consisted of 21 and 47 patients, respectively. There was no significant difference in the conversion rates between the two groups (0 vs 8.5% in vNOTES and LESS, respectively; p = 0.303). Compared with the vNOTES group, the LESS group had a larger cyst diameter (6.00 ± 2.32 vs 4.69 ± 1.29 cm; p = 0.004), more endometriotic cysts (42.6% vs 9.5%; p < 0.001), and more pelvic adhesions requiring adhesiolysis (57.4% vs 19.0%; p = 0.003). At baseline, there were no other differences between the groups. The secondary outcomes included a shorter duration of surgery (70.14 ± 27.30 vs 99.57 ± 36.26 minutes; p = 0.001) and lower estimated blood loss (64.29 ± 39.19 vs 163.43 ± 251.20 mL; p = 0.011) in the vNOTES group. Regression analysis showed the diameter of the ovarian cyst correlated with surgical time. The complication was comparable between the two groups.

CONCLUSION

Above all, the advantages of vNOTES include an absence of visible scars, shorter surgical duration, and less blood loss when compared with LESS. Further large-scale prospective trials should confirm the results of our study.

Standardised step by step approach to adnexectomy by Vaginal Natural Orifice Transluminal Endoscopic Surgery

Vaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) combines the advantages of vaginal surgery with those of laparoscopic surgery. Feasibility of vNOTES for other indications such as hysterectomy, ovarian cystectomy and myomectomy has been established. In this article, we describe a standardised step by step process to perform adnexal surgery by vNOTES.

Comparison of Surgical Outcomes of Hysterectomy by Vaginal Natural Orifice Transluminal Endoscopic Surgery (vNOTES) versus Single-Port Access (SPA) Surgery

Single-port access (SPA) laparoscopic surgery and vaginal natural orifice transluminal endoscopic surgery (vNOTES) have many advantages. The objective of the present study is to compare patient characteristics, operative details, and postoperative outcomes between the two surgical methods. Patients who were planned to undergo vNOTES or SPA laparoscopic surgery between April 2020 and June 2021 were prospectively enrolled. The surgical method was determined by a single surgeon after imaging results evaluation and a physical exam. Those who had favorable pelvic conditions without any evidence of adhesion were scheduled for vNOTES. A total of 33 patients underwent a vNOTES hysterectomy while 40 patients received a SPA laparoscopic hysterectomy. All surgeries were performed by one surgeon. The proportion of the patients who had a history of vaginal delivery was significantly higher in the vNOTES group. The operative time for port installation was significantly longer in the vNOTES group, but the total operative time was shorter compared to the SPA group. The postoperative pain scores 12 h after the operations were also significantly lower in the vNOTES group. Other surgical outcomes were comparable between the two groups. The present study demonstrated that the early operative outcomes of vNOTES hysterectomy were comparable to those of SPA hysterectomy. It also highlights the importance of adequate patient selection when determining surgical methods based on imaging results and physical examinations.

vNOTES for adnexal procedures

This work aims to describe the technique and review all transvaginal natural orifice transluminal endoscopic surgery (vNOTES) for adnexal procedures performed and to acknowledge vNOTES as an alternative to conventional laparoscopy. The procedure consisted of an incision in the Pouch of Douglas, insertion of a single port device, laparoscopic surgery through the device, extraction of specimens through the vagina and closure of the vaginal apex with a direct suture. Eighteen procedures have been successfully completed, 1 patient required conversion to conventional abdominal surgery due to intolerance to pneumoperitoneum. Surgeries' length range was 45-210 minutes. The estimated blood loss was less than 100 mL. The patients required minimal analgesia, were discharged the day after and had no postoperative complications. No patients complained of dyspareunia. Two patients conceived after surgery. vNOTES is a safe and desirable approach to the adnexa and a reasonable alternative to conventional laparoscopy or vaginal surgery.Impact statementWhat is already known on this subject? Natural Orifice Transluminal Surgery (NOTES) is a technique used to access the abdominal cavity through natural orifice. Compared to conventional laparoscopy, it's expected to have fewer complications.What do the results of this study add? This is one of the few works addressing vNOTES adnexal surgery, which appears to be a good alternative to conventional laparoscopy.What are the implications of these findings for clinical practice and/or further research? vNOTES may be a desirable approach to the adnexa. This work opens a door to new research regarding vNOTES in more complex gynaecologic procedures.

A spontaneous heterotopic pregnancy presenting with acute abdomen treated with natural orifice transluminal endoscopic surgery procedure: Case report

Heterotopic pregnancy occurs 1 in 30000 pregnancies. We present case of an acute abdomen caused by a ruptured ectopic component. Our patient had no known risk factors, which made the diagnosis even more challenging. Intrauterine pregnancy was desired by patient and her husband. A natural orifice transluminal endoscopic surgery (NOTES) procedure was performed, which is a next-generation minimally invasive procedure in this area. After the procedure, our patient was discharged one day after surgery with a viable intrauterine pregnancy.

Face and content validation of a Virtual Translumenal Endoscopic Surgery Trainer (VTEST™)

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) is an emerging surgical paradigm, where peritoneal access is achieved through one of the natural orifices of the body. It is being reported as a safe and feasible surgical technique with significantly reduced external scarring. Virtual Translumenal Endoscopic Surgical Trainer (VTEST™) is the first virtual reality simulator for the NOTES. The VTEST™ simulator was developed to train surgeons in the hybrid transvaginal NOTES cholecystectomy procedure. The initial version of the VTEST™ simulator underwent face validation at the 2013 Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) summit. Several areas of improvement were identified as a result, and the corresponding modifications were implemented in the simulator. This manuscript outlines the results of the subsequent evaluation study, performed in order to assess the face and content validity of the latest VTEST™ simulator.

METHODS

Twelve subjects participated in an institutional review board-approved study that took place at the 2014 NOSCAR summit. Six of the 12 subjects, who are experts with NOTES experience, were used for face and content validation. The subjects performed the hybrid transvaginal NOTES cholecystectomy procedure on VTEST™ that included identifying the Calot's triangle, clipping and cutting the cystic duct/artery, and detaching the gallbladder. The subjects then answered five-point Likert scale feedback questionnaires for face and content validity.

RESULTS

Overall, subjects rated 12/15 questions as 3.0 or greater (60 %), for face validity questions regarding the realism of the anatomical features, interface, and the tasks. Subjects also highly rated the usefulness of the simulator in learning the fundamental NOTES technical skills (3.50 ± 0.84). Content validity results indicate a high level of usefulness of the VTEST™ for training prior to operating room experience (4.17 ± 0.75).

Graphic and haptic simulation for transvaginal cholecystectomy training in NOTES

BACKGROUND

Natural Orifice Transluminal Endoscopic Surgery (NOTES) provides an emerging surgical technique which usually needs a long learning curve for surgeons. Virtual reality (VR) medical simulators with vision and haptic feedback can usually offer an efficient and cost-effective alternative without risk to the traditional training approaches. Under this motivation, we developed the first virtual reality simulator for transvaginal cholecystectomy in NOTES (VTEST™).

METHODS

This VR-based surgical simulator aims to simulate the hybrid NOTES of cholecystectomy. We use a 6DOF haptic device and a tracking sensor to construct the core hardware component of simulator. For software, an innovative approach based on the inner-spheres is presented to deform the organs in real time. To handle the frequent collision between soft tissue and surgical instruments, an adaptive collision detection method based on GPU is designed and implemented. To give a realistic visual performance of gallbladder fat tissue removal by cautery hook, a multi-layer hexahedral model is presented to simulate the electric dissection of fat tissue.

RESULTS

From the experimental results, trainees can operate in real time with high degree of stability and fidelity. A preliminary study was also performed to evaluate the realism and the usefulness of this hybrid NOTES simulator.

CONCLUSIONS

This prototyped simulation system has been verified by surgeons through a pilot study. Some items of its visual performance and the utility were rated fairly high by the participants during testing. It exhibits the potential to improve the surgical skills of trainee and effectively shorten their learning curve.

[Natural orifice transluminal endoscopic surgery in Germany: Data from the German NOTES registry]

BACKGROUND

The German NOTES registry (GNR) was initiated by the German Society for General and Visceral Surgery (DGAV) as a treatment and outcome database for natural orifice transluminal endoscopic surgery (NOTES).

AIM

The aim of this study was the descriptive analysis of all GNR data collected over a 5-year period since its start in 2008 with more than 3000 interventions.

MATERIAL AND METHODS

The GNR is an online database with voluntary participation available to all German-speaking clinics. Demographic data, therapy details, complications and data on the postoperative course of patients are recorded. All cases in the GNR between March 2008 and November 2013 were included in the analysis.

RESULTS

From a total of 3150 data sets 2992 (95 %) were valid and suited for the analysis. Hybrid transvaginal cholecystectomy was the most frequently used procedure (88.7 %), followed by hybrid transvaginal/transgastric appendectomy (6.1 %) and hybrid transvaginal/transrectal colon procedures (5.1 %). Intraoperative complications occurred in 1.6 %, postoperative complications in 3.7 % and conversions were reported in 1.5 %. Intraoperative bladder injuries and postoperative urinary tract infections were identified as method-specific complications of transvaginal procedures. Bowel injuries occurred as a rare (0.2 %) but potentially serious complication of transvaginal operations.

CONCLUSION

The German surgical community ensures a safe and responsible introduction of the new NOTES operation techniques with its active participation in the GNR. Despite an overall low complication rate, the high number of procedures in the GNR permitted the identification of method-specific complications. This knowledge can be used to further increase the safety of NOTES in practice.

A multicenter study of initial experience with single-incision robotic cholecystectomies (SIRC) demonstrating a high success rate in 465 cases

BACKGROUND

Recently, the robotic single-site platform has been used to ameliorate the difficulties seen in single-incision laparoscopic surgery (SILC) while preserving the benefits of standard laparoscopic cholecystectomy. The purpose of this study is to describe the clinical outcomes of a large series of single-incision robotic cholecystectomy (SIRC).

METHODS

Medical records of consecutive patients who underwent SIRC were retrospectively reviewed. All procedures were performed by six surgeons at five different North American centers involved in the study. All patients included in the study underwent a cholecystectomy attempted through single site at the umbilicus, using the da Vinci(®) Surgical System (Intuitive Surgical Inc. Sunnyvale, CA).

RESULTS

A total of 465 patients met study criteria. Median age was 48 years (range 18-89); 351 (75.5 %) were female and 304 (66.4 %) were overweight or obese. Except for gender, case characteristics differed significantly by surgeon/site. Previous abdominal surgery was reported for 226 (48.6 %) cases. SIRC was successfully completed in 455 (97.8 %) cases, and there were no conversions to open surgery. Median surgical time was 52 min with a decreasing trend after 55-85 cases. Male gender, obesity and diagnoses other than biliary dyskinesia were independent predictors of longer surgical times. The complication rate was 2.6 %.

CONCLUSIONS

Our large, multicenter study demonstrates that robotic single-site cholecystectomy is safe and feasible in a wide range of patients.

Comparison of outcome and side effects between conventional and transvaginal laparoscopic cholecystectomy: a meta-analysis

Transvaginal laparoscopic cholecystectomy (TVC) is becoming an attractive alternative to conventional laparoscopic cholecystectomy (CLC). We conducted a meta-analysis study to compare the outcome and side effects between TVC and CLC. Clinical studies on TVC with CLC as control were identified by searching PubMed and EMBASE (from 2007 to December 2013). Nine studies were identified for meta-analysis. Our results showed that TVC required much longer operative time [MD, 30.82; 95% confidence interval (CI), 13.00-48.65; P=0.0007] and had significantly lower pain score on postoperative day 1 as compared with CLC (MD, -1.77; 95% CI, -2.91 to -0.63; P=0.002). No statistical difference in days of hospital stay (MD, -1.60; 95% CI, -4.73 to 1.54; P=0.32) and number of complications was found between the 2 groups (risk ratio, 0.52; 95% CI, 0.25-1.10; P=0.09). Safety of TVC is similar as CLC. In conclusion, TVC patients have significantly less postoperative pain but need much longer operative time.

A randomized controlled trial comparing post-operative pain in single-incision laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy

INTRODUCTION

An increasing body of evidence is being published about single-incision laparoscopic cholecystectomy (SILC), but there are no well-powered trials with an adequate evaluation of post-operative pain. This randomized trial compares SILC against four-port laparoscopic cholecystectomy (LC) with post-operative pain as the primary endpoint.

METHODS

Hundred patients were randomized to either SILC (n = 50) or LC (n = 50). Exclusion criteria were (1) Acute cholecystitis; (2) ASA 3 or above; (3) Bleeding disorders; and (4) Previous open upper abdominal surgery. Patients and post-operative assessors were blinded to the procedure performed. The site and severity of pain were compared at 4 h, 24 h, 14 days and 6 months post-procedure using the visual analog scale; non-inferiority was assumed when the lower boundary of the 95% confidence interval of the difference was above -1 and superiority when p ≤ 0.05.

RESULTS

The study arms were demographically similar. At 24 h post-procedure, SILC was associated with less pain at extra-umbilical sites (rest: p = 0.004; movement: p = 0.008). Pain data were inconclusive at 24 h at the umbilical site on movement; SILC was otherwise non-inferior for pain at all other points. Operating duration was longer in SILC (79.46 vs 58.88 min, p = 0.003). 8% of patients in each arm suffered complications (p = 1.000). Re-intervention rates, analgesic use, return to function, and patient satisfaction did not differ significantly.

CONCLUSIONS

SILC has improved short-term pain outcomes compared to LC and is not inferior in both short-term and long-term pain outcomes. The operating time is longer, but remains feasible in routine surgical practice.

Single-incision laparoscopic cholecystectomy: will it succeed as the future leading technique for gallbladder removal?

BACKGROUND

The quest for less traumatic abdominal approaches is changing paradigms in times of minimally invasive surgery. While natural orifice translumenal endoscopic surgery remains experimental, the single-incision approach could be the future of gallbladder surgery.

METHODS

Prospectively collected data from 875 patients subjected to conventional single-incision laparoscopic cholecystectomy (SILC) or 4-port [laparoscopic cholecystectomy (LC)] were retrospectively analyzed and discussed with the current literature.

RESULTS

Between 2008 and 2011, 201 (23%) SILCs and 674 (77%) LCs were performed. Mean age was 51.7±17.5 years (SILC: 45.1 vs. LC: 53.7 y). Patients were predominantly female (SILC: 75.1% vs. LC: 56.5%). Preoperative body mass index was 27.4±9.1 (SILC: 26.4 vs. LC: 27.8; P<0.05) and American Society of Anesthesiologists' score counted 1.67±0.57 in SILC and 1.86±0.7 in LC patients. Acute inflammation of the gallbladder (AIG) was not considered as a contraindication for SILC (AIG in SILC: 17.4% vs. LC: 35.5%). The mean operative time was significantly lower in the SILC group (SILC: 71±31 vs. LC: 79±27 min) and duration of postoperative hospital stay was shorter (SILC: 3.2±1.7 vs. LC: 4.5±2.6 d). No significant difference was observed between SILC and LC in any of the registered complications, including postoperative bleeding, trocar hernias, wound infection, abdominal abscess formation, bile duct injury, or cystic duct leakage.

CONCLUSIONS

In the near future SILC could overrule conventional LC as the leading technique for gallbladder surgery. Our data reconfirm an excellent risk profile for SILC that is equal to that of LC. Large multicenter randomized controlled trials will be required to finally legitimize SILC as the succeeding principal method.

Women’s Perception of Transvaginal Natural Orifice Transluminal Endoscopic Surgery (NOTES)

Objective. Over the past 8 years, natural orifice transluminal endoscopic surgery (NOTES) has developed from preclinical to routine clinical practice. However, there are still concerns regarding the transvaginal approach. In our survey, we were interested in females with a professional medical background, thus having at least a basic medical understanding, which might discriminate between objective and subjective concerns. Material and Methods. A questionnaire with 14 items was distributed among 1895 female physicians and nursing and administration staff of the University Medical Center Hamburg-Eppendorf. In addition, a qualitative literature review was performed. Data analysis was carried out using statistical package R version 2.15.0. Results. The questionnaire was answered anonymously by 553 employees (29%). Fifty-seven percent were nurses, 18.6% belonged to administration, and 17% were physicians. A total of 63.1% of our respondents would choose the transvaginal NOTES technique for an assumed ovariectomy, while only 30.4% would choose this access for cholecystectomy. Doubts regarding transvaginal NOTES were related to sexual dysfunction (44.8%), its experimental nature (43.8%), future pregnancies (36.8%), and ethical reasons (30.3%). The literature review showed that women’s perception of the transvaginal access is documented very heterogeneously and therefore difficult to compare. Conclusions. Despite the good reported results of NOTES and the medical background of the surveyed female employees, our study and the literature review clearly shows that there are  fears regarding the transvaginal access, which might be a result of limited information. More accurate explanation of the available methods by the attending surgeon can lead to a better choice of the patient’s preferred method.

Natural orifice translumenal endoscopic surgery (NOTES): emerging trends and specifications for a virtual simulator

INTRODUCTION AND STUDY AIM

A virtual translumenal endoscopic surgical trainer (VTEST) is being developed to accelerate the development of natural orifice translumenal endoscopic surgery (NOTES) procedures and devices in a safe and risk-free environment. For a rapidly developing field such as NOTES, a needs analysis must be conducted regularly to discover emerging research trends and areas of potential high impact for a virtual simulator. This paper presents a survey-based study which follows a similar study conducted by this group in 2011 (Sankaranarayanan et al. in Surg Endosc 27:1607-1616, 2013).

METHODS

A 32-point questionnaire was distributed at the 2012 Natural Orifice Surgery Consortium for Assessment and Research annual meeting. These data were subsequently augmented by an identical online survey, targeted at the members of the American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons, and analyzed.

RESULTS

Twenty-eight NOTES experts participated in the 2012 study. Cholecystectomy (CE) procedure remained the most commonly performed NOTES technique, with 18 positive responses (64%). In contrast to 2011, the popularity of the NOTES appendectomy (AE) was significantly lower, with only 2 (7%) instances (CE vs. AE, p < 0.001), while the number of peroral endoscopic myotomy (POEM, PE) cases had increased significantly, with 11 (39%) positive responses, respectively (PE vs. AE, p = 0.013). Strong preference toward hybrid rather than pure NOTES techniques (82 vs. 11%, p < 0.001) was also expressed. Other responses were similar to those in the 2011 study, with the VTEST™ utility in developing and testing new techniques and instruments ranked particularly high.

CONCLUSION

Based on the results of this study, a decision was made to focus exclusively on the transvaginal hybrid NOTES cholecystectomy procedure, including both rigid and flexible scope techniques. The importance of developing a virtual NOTES simulator was reaffirmed, with POEM identified as a promising candidate for future simulator development.

Transvaginal organ extraction: potential for broad clinical application

BACKGROUND

Natural orifice transluminal endoscopic surgery procedures have evolved over the past few years. A transvaginal approach is a promising alternative for intraperitoneal procedures. Our objective was to evaluate the safety and feasibility of transvaginal organ extraction.

METHODS

This institutional review board-approved protocol involved retrospective review of an ongoing prospective study. Female subjects who presented to our hospital for elective cholecystectomy, appendectomy, or sleeve gastrectomy were offered participation in the study. Eligible patients met the following criteria: age between 18 and 75, diagnosis of gallbladder disease, acute appendicitis, or morbid obesity who desired surgical treatment. A hybrid transvaginal natural orifice approach was used in this series.

RESULTS

Thirty-four women underwent transvaginal organ extraction between September 2007 and January 2012. The mean age was 40 ± 12.1 years (range 23-63 years). The mean body mass index was 27 ± 6.4 kg/m(2) (range 16-43 kg/m(2)). All patients had an American Society of Anesthesiologists classification of two or below. The mean operative time for cholecystectomy, appendectomy, and sleeve gastrectomy was 90, 71, and 135 min, respectively. There were no conversions to open operation and no intraoperative complications. The mean hospital stay was 2 days for all cases. Patients were followed for a mean of 24 months (range 1-61 months). There were two pregnancies and two successful vaginal deliveries. Six patients (18 %) had minor complaints of spotting or heavy menses in the immediate postoperative period that resolved with conservative measures. There were no abdominal wall complications. There were no long-term complications and no mortalities.

CONCLUSIONS

This initial experience suggests that this surgical approach is safe, does not increase length of stay, and has no long-term vaginal complications. Given this attractive profile, a transvaginal approach may prove to be a superior mode of organ extraction, although randomized studies and long-term follow-up are needed.

Pure NOTES transvaginal appendectomy with gasless laparoscopy

BACKGROUND

The vagina is the most widely used approach to natural orifice transluminal endoscopic surgery. However, a gas leak can significantly affect transvaginal operations during pneumoperitoneum laparoscopy. We tried to establish the proper technique for transvaginal appendectomy under gasless laparoscopy.

MATERIALS AND METHODS

Five patients with chronic appendicitis were selected to receive gasless laparoscopic transvaginal appendectomy with concurrent vaginal hysterectomy. An abdominal wall-lifting device was applied after removal of the uterus, and the appendix was removed transvaginally. Clinical data such as operative duration, bleeding volume, morbidity, and hospital stay duration were analyzed.

RESULTS

All procedures were performed successfully, without intraoperative or major postoperative complications. The appendectomy portion of the procedure took approximately 20-30 minutes, with minimal blood loss. All patients were discharged, scar-free, 3 d after surgery.

CONCLUSIONS

Transvaginal appendectomy with gasless laparoscopy after vaginal hysterectomy appears to be a feasible and safe modification of established techniques, with acceptable outcomes.

Comparison of hemodynamic and inflammatory changes between transoral and transthoracic thoracoscopic surgery

BACKGROUND

Natural orifice transluminal endoscopy has been developed for abdominal surgical procedures. The aim of this study was to compare the surgical outcome between a novel transoral approach and a standard transthoracic approach for the thoracic cavity in a canine model.

METHODS

Twenty-eight dogs were assigned to transoral (n = 14) or standard thoracoscopy (n = 14). Each group underwent thoracic exploration, pre-determined surgical lung biopsy, and pericardial window creation. Blood draws were obtained before surgery and at postoperative days 1, 3, 7, and 14. Operative time, complications, laboratory parameters, hemodynamic parameters, and inflammatory parameters were compared between the two procedures. The animals were monitored for two weeks and necropsy were performed for surgical outcome evaluation.

RESULTS

The thoracic procedures were successfully performed in all of the dogs, with the exception of one animal in the transoral group. There were no serious acute or delayed complications related to surgery. There was no difference between the two surgical groups for each of the hemodynamic parameters that were evaluated. Regarding the immunological impact of the surgeries, transoral thoracoscopy was associated with significant elevations in interleukin 6 and c-reactive protein levels on postoperative days 1 and 3, respectively, when compared with the standard thoracoscopy. All dogs recovered well, without signs of mediastinitis or thoracic infection. Necropsy revealed absence of infection, no injury to vital organs, and confirmed the success of the novel procedure.

CONCLUSIONS

This study suggests that both techniques were comparable with respect to procedure success rate, hemodynamic impact, and inflammatory changes. Furthermore, there was no difference in the incidence of postoperative discomfort between groups.

Needs analysis for developing a virtual-reality NOTES simulator

INTRODUCTION AND STUDY AIM: Natural orifice translumenal endoscopic surgery (NOTES) is an emerging surgical technique that requires a cautious adoption approach to ensure patient safety. High-fidelity virtual-reality-based simulators allow development of new surgical procedures and tools and train medical personnel without risk to human patients. As part of a project funded by the National Institutes of Health, we are developing the virtual transluminal endoscopic surgery trainer (VTEST) for this purpose. The objective of this study is to conduct a structured needs analysis to identify the design parameters for such a virtual-reality-based simulator for NOTES.

METHODS

A 30-point questionnaire was distributed at the 2011 National Orifice Surgery Consortium for Assessment and Research meeting to obtain responses from experts. Ordinal logistic regression and the Wilcoxon rank-sum test were used for analysis.

RESULTS

A total of 22 NOTES experts participated in the study. Cholecystectomy (CE, 68 %) followed by appendectomy (AE, 63 %) (CE vs AE, p = 0.0521) was selected as the first choice for simulation. Flexible (FL, 47 %) and hybrid (HY, 47 %) approaches were equally favorable compared with rigid (RI, 6 %) with p < 0.001 for both FL versus RI and HY versus RI. The transvaginal approach was preferred 3 to 1 to the transgastric. Most participants preferred two-channel (2C) scopes (65 %) compared with single (1C) or three (3C) or more channels with p < 0.001 for both 2C versus 1C and 2C versus 3C. The importance of force feedback and the utility of a virtual NOTES simulator in training and testing new tools for NOTES were rated very high by the participants.

CONCLUSION

Our study reinforces the importance of developing a virtual NOTES simulator and clearly presents expert preferences. The results of this analysis will direct our initial development of the VTEST platform.