Transcolonic endoscopic cholecystectomy: a NOTES survival study in a porcine model (with video)

Integrated Sensors for Soft Medical Robotics

Minimally invasive procedures assisted by soft robots for surgery, diagnostics, and drug delivery have unprecedented benefits over traditional solutions from both patient and surgeon perspectives. However, the translation of such technology into commercialization remains challenging. The lack of perception abilities is one of the obstructive factors paramount for a safe, accurate and efficient robot-assisted intervention. Integrating different types of miniature sensors onto robotic end-effectors is a promising trend to compensate for the perceptual deficiencies in soft robots. For example, haptic feedback with force sensors helps surgeons to control the interaction force at the tool-tissue interface, impedance sensing of tissue electrical properties can be used for tumor detection. The last decade has witnessed significant progress in the development of multimodal sensors built on the advancement in engineering, material science and scalable micromachining technologies. This review article provides a snapshot on common types of integrated sensors for soft medical robots. It covers various sensing mechanisms, examples for practical and clinical applications, standard manufacturing processes, as well as insights on emerging engineering routes for the fabrication of novel and high-performing sensing devices.

Are laparoscopic cholecystectomy and natural orifice transluminal endoscopic surgery gallbladder preserving cholecystolithotomy truly comparable? A propensity matched study

BACKGROUND

Cholecystectomy is the preferred treatment option for symptomatic gallstones. However, another option is gallbladder-preserving cholecystolithotomy which preserves the normal physiological functions of the gallbladder in patients desiring to avoid surgical resection.

AIM

To compare the feasibility, safety and effectiveness of pure natural orifice transluminal endoscopic surgery (NOTES) gallbladder-preserving cholecystolithotomy vs laparoscopic cholecystectomy (LC) for symptomatic gallstones.

METHODS

We adopted propensity score matching (1:1) to compare trans-rectal NOTES cholecystolithotomy and LC patients with symptomatic gallstones. We reviewed 2511 patients with symptomatic gallstones from December 2017 to December 2020; 517 patients met the matching criteria (NOTES, 110; LC, 407), yielding 86 pairs.

RESULTS

The technical success rate for the NOTES group was 98.9% vs 100% for the LC group. The median procedure time was 119 min [interquartile ranges (IQRs), 95-175] with NOTES vs 60 min (IQRs, 48-90) with LC (P < 0.001). The frequency of post-operative pain was similar between NOTES and LC: 4.7% (4/85) vs 5.8% (5/95) (P = 0.740). The median duration of post-procedure fasting with NOTES was 1 d (IQRs, 1-2) vs 2 d with LC (IQRs, 1-3) (P < 0.001). The median post-operative hospital stay for NOTES was 4 d (IQRs, 3-6) vs 4 d for LC (IQRs, 3-5), (P = 0.092). During follow-up, diarrhea was significantly less with NOTES (5.8%) compared to LC (18.6%) (P = 0.011). Gallstones and cholecystitis recurrence within a median of 12 mo (range: 6-40 mo) following NOTES was 10.5% and 3.5%, respectively. Concerns regarding the presence of abdominal wall scars were present in 17.4% (n = 15/86) of patients following LC (mainly women).

CONCLUSION

NOTES provides a feasible new alternative scar-free treatment for patients who are unwilling or unable to undergo cholecystectomy. This minimally invasive organ-sparing procedure both removes the gallstones and preserves the physiological function of the gallbladder. Reducing gallstone recurrence is essential to achieving widespread clinical adoption of NOTES.

A reliable detachable balloon that prevents abdominal cavity contamination during transrectal natural orifice transluminal endoscopic surgery

OBJECTIVE

To evaluate the efficacy and safety of a detachable endoluminal balloon in the prevention of abdominal cavity contamination during transrectal natural orifice transluminal endoscopic surgery (NOTES).

METHODS

The efficacy and safety of a detachable endoluminal balloon to maintain disinfection in the distal colon of the pigs were evaluated. The bacterial loads and colonic cleanliness were monitored. Additionally, the device was applied to another nine pigs that underwent a cholecystotomy by transrectal NOTES. Necropsy and pathological examination were performed after 28-day follow-up.

RESULTS

All animals exposed to the device and one of the seven pigs not exposed to the device scored three points on the bowel cleanliness scale (P < 0.001). After 30 min bacterial loads of the test (with balloon occlusion) and control (without balloon occlusion) groups showed a significant difference (0.8 × 10³  CFU/mL vs 186.8 × 10³  CFU/mL, P < 0.01). Cholecystotomy by transrectal NOTES with the device was successfully performed. The mean intraperitoneal procedure time was 102.9 ± 37.7 min. There were no procedure-related adverse events. During the follow-up, all animals presented normal behavior and appetite. No peritoneal infection or adhesion was detected at autopsy. Cholecystotomy and rectal incision were histologically healed and no histological abnormalities were detected in the colon related to balloon placement.

CONCLUSIONS

The detachable balloon provides a reliable solution for preventing peritoneal contamination during transluminal operations. The technique may assist in future transrectal NOTES.

Feasibility and Technique for Transvaginal Natural Orifice Transluminal Endoscopic Surgery Liver Resection: A Porcine Model

INTRODUCTION

Natural orifice transluminal endoscopic surgery (NOTES) is a challenging minimally invasive procedure. Although laparoscopic techniques for liver resection are gaining acceptance worldwide, few studies have investigated NOTES liver resection. We used a porcine model to assess the feasibility and safety of transvaginal NOTES liver resection (TV NOTES LR).

MATERIALS AND METHODS

Nine female pigs underwent TV NOTES LR. A nonsurvival acute porcine model with general anesthesia was used in all cases. Using hybrid NOTES technique, we placed only 1 umbilical 12-mm umbilical trocar in the abdominal wall, which was used to create pneumoperitoneum. A laparoscope was then advanced to obtain intra-abdominal visualization. A 15-mm vaginal trocar was inserted under direct laparoscopic vision, and a flexible endoscope was introduced through the vaginal trocar. A long, flexible grasper and endocavity retractor were used to stably retract the liver. The liver edge was partially transected using energy devices inserted through the umbilical trocar. To transect the left lateral lobe, a flexible linear stapler was inserted alongside the vaginal trocar. A specimen extraction bag was deployed and extracted transvaginally. Blood loss, bile leakage, operative time, and specimen size were evaluated. Necropsy studies were performed after the procedures.

RESULTS

Eighteen transvaginal NOTES partial liver resections and 4 transvaginal NOTES left lateral lobectomies were successfully performed on 9 pigs. Mean operative time was 165.8 minutes, and mean estimated blood loss was 76.6 mL. All TV NOTES LRs were performed without complications or deaths. Necropsy showed no bile leakage from remnant liver.

CONCLUSIONS

Our porcine model suggests that TV NOTES LR is technically feasible and safe and has the potential for clinical use as a minimally invasive alternative to conventional laparoscopic liver resection.

Current and emerging robotic assisted intervention for Notes

INTRODUCTION

Natural orifices transluminal endoscopic surgery (notes) procedures are limited by a number of factors including closure of the internal entry point, loss of triangulation, and unstable operative platform. Areas covered: In this paper, new technical developments in different aspects of robotic assisted NOTES interventions are reviewed. We further address new research opportunities for more widespread clinical acceptance of robotic assisted NOTES procedures. Expert commentary: The application of robotics in NOTES intervention is still in its infancy. The development of more compact, smart and intuitive robotic NOTES systems holds much promise for the future of NOTES application.

Development of a Haptic Interface for Natural Orifice Translumenal Endoscopic Surgery Simulation

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive procedure, which utilizes the body's natural orifices to gain access to the peritoneal cavity. The NOTES procedure is designed to minimize external scarring and patient trauma, however flexible endoscopy based pure NOTES procedures require critical scope handling skills. The delicate nature of the NOTES procedure requires extensive training. Thus, to improve access to training while reducing risk to patients, we have designed and developed the VTEST, a virtual reality NOTES simulator. As part of the simulator, a novel decoupled 2-DOF haptic device was developed to provide realistic force feedback to the user in training. A series of experiments were performed to determine the behavioral characteristics of the device. The device was found capable of rendering up to 5.62N and 0.190 Nm of continuous force and torque in the translational and rotational DOF, respectively. The device possesses 18.1 and 5.7 Hz of force bandwidth in the translational and rotational DOF, respectively. A feedforward friction compensator was also successfully implemented to minimize the negative impact of friction during the interaction with the device. In this work, we have presented the detailed development and evaluation of the haptic device for the VTEST.

The Future of Teaching Surgical Endoscopy

Gastrointestinal surgery, with its emphasis on endoscopy, has renewed interest in teaching surgical endoscopy. The field is rapidly evolving, with innovative techniques emanating from the laboratory to the operating room and endoscopy suite. To ensure that surgeons spearhead the field of endoscopic surgery, a new strategy for teaching surgical endoscopy to residents and practicing surgeons must be developed.

Transvaginal Laparoscopically Assisted Endoscopic Appendectomy: a major Hybrid Natural Orifice Transluminal Endoscopic Surgery case series in Asia

OBJECTIVE

Evaluation of a Hybrid Approach to NOTES and its performance relative to conventional procedures.

BACKGROUND

Globally, numerous institutions have successfully implemented minimally invasive surgeries by applying natural orifice translumenal endoscopic surgery (NOTES) techniques and achieved decreased morbidity while performing incision-less surgery. However, these techniques are still not common in surgical practice in China and Pakistan. Documenting the experiences and challenges encountered in implementing NOTES in such environments can provide guidance for NOTES implementation elsewhere.

METHODS

From May 2010 to April 2012, 16 human transvaginal appendectomies were carried out applying a hybrid NOTES technique using a solo-umbilical trocar, which provided a safe access for laparoscopic assistance during surgical procedure. After removal of the appendix transvaginally, the colpotomy was sutured under direct vision with absorbable stitches. The outcomes of cases treated with hybrid NOTES techniques were compared to those of conventional laparoscopic appendectomy.

RESULTS

All patients underwent a successful surgical procedure with no intra- or post-operative complications and provided no specific complaints during the tenth day and a monthly follow-up for 2 years. The patients convalesced promptly with healthy and satisfactory cosmetic results. Compared to conventional laparoscopic appendectomy, the hybrid NOTES operation had less post-operative pain, lower cost, and shorter hospitalization.

CONCLUSIONS

Hybrid NOTES procedures can be performed safely using a solo-umbilical trocar. Our initial experience reveals that this hybrid technique is practically feasible and associated with minimal post-operative pain, reasonable convalescence time, and improved cosmetic outcomes.

Application of robotics in gastrointestinal endoscopy: A review

Multiple robotic flexible endoscope platforms have been developed based on cross specialty collaboration between engineers and medical doctors. However, significant number of these platforms have been developed for the natural orifice transluminal endoscopic surgery paradigm. Increasing amount of evidence suggest the focus of development should be placed on advanced endolumenal procedures such as endoscopic submucosal dissection instead. A thorough literature analysis was performed to assess the current status of robotic flexible endoscopic platforms designed for advanced endolumenal procedures. Current efforts are mainly focused on robotic locomotion and robotic instrument control. In the future, advances in actuation and servoing technology, optical analysis, augmented reality and wireless power transmission technology will no doubt further advance the field of robotic endoscopy. Globally, health systems have become increasingly budget conscious; widespread acceptance of robotic endoscopy will depend on careful design to ensure its delivery of a cost effective service.

Shifting Paradigms in Minimally Invasive Surgery: Applications of Transanal Natural Orifice Transluminal Endoscopic Surgery in Colorectal Surgery

Since the advent of laparoscopy, minimally invasive techniques such as single port laparoscopy, robotics, endoscopically assisted laparoscopy, and transanal endoscopic surgery continue to revolutionize the field of colorectal surgery. Transanal natural orifice transluminal endoscopic surgery (NOTES) represents a further paradigm shift by combining the advantages of these earlier techniques to reduce the size and number of abdominal incisions and potentially optimize rectal dissection, especially with respect to performance of an oncologically adequate total mesorectal excision (TME) for rectal cancer. Since the first experimental report of transanal rectosigmoid resection in 2007, the potential impact of transanal NOTES in colorectal surgery has been extensively investigated in experimental models and recently transitioned to clinical application. There have been 14 clinical trials of transanal TME (taTME) for rectal cancer that have demonstrated the feasibility and preliminary oncologic safety of this approach in carefully selected patients, with results comparable to outcomes after laparoscopic and open TME, including cumulative intraoperative and postoperative complication rates of 5.5 and 35.5%, respectively, 97.3% rate of complete or near-complete specimens, and 93.6% rate of negative margins. Transanal NOTES has also been safely applied to proctectomy and colectomy for benign indications. The consensus among published series suggests that taTME is most safely performed with transabdominal assistance by surgeons experienced with laparoscopic TME, transanal endoscopic surgery, and sphincter-preserving techniques including intersphincteric resection. Future applications of transanal NOTES may include evolution to a pure endoscopic transanal approach for TME, colectomy, and sentinel lymph node biopsy for rectal cancer, with a potential role for robotic assistance.

Randomized trial on the physiologic impact of NOTES

BACKGROUND

Our previous work revealed significantly less acidosis in swine undergoing natural orifice translumenal endoscopic surgery (NOTES) using endoscopic air insufflation than swine undergoing standard laparoscopy. We wanted to evaluate the differential effects of CO2 versus intra-abdominal pressure as source for this finding. In addition, we investigated the endocrine stress response between swine undergoing NOTES peritoneoscopy with CO2 insufflation and animals undergoing standard diagnostic laparoscopy with CO2.

MATERIALS AND METHODS

Twenty-eight (28) female 50-kg domestic pigs were randomly assigned to one of four groups using a permuted block randomization table: Group 1: NOTES using CO2 insufflation, Group 2: NOTES using air insufflation, Group 3: laparoscopy max pressure 12 mmHg and Group 4: laparoscopy with max pressure 7 mmHg. Invasive monitoring lines were placed. Pneumoperitoneum was established by the respective method and maintained for 90 min, visualizing liver, spleen and colon. Arterial blood gas was obtained at baseline and four additional time points. Serum TNF-α for POD (postoperative day) 1 and cumulative urine adrenaline for the procedure were determined by ELISA. ANOVA and t test were used for statistical comparison. The study was Institutional Animal Care and Use Committees approved.

RESULTS

All experiments were completed as outlined. Blood pH showed a significant difference between groups. Serum TNF-α revealed higher levels for NOTES CO2 on POD 1 than standard laparoscopy (p = 0.03).

CONCLUSION

NOTES animals with CO2 insufflation initially experienced similar pH compared to standard laparoscopy but recovered to levels seen in low-pressure laparoscopy and NOTES with air. NOTES with CO2 appears to elicit a stronger stress response in this study than standard or low-pressure laparoscopy or NOTES with air.

System characterization of a novel haptic interface for natural orifice translumenal endoscopic surgery simulation

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive procedure, which utilizes the body's natural orifices to gain access to the peritoneal cavity. The VTEST(©) is a virtual reality NOTES simulator developed at the CeMSIM at RPI to train surgeons in NOTES. A novel 2 DOF decoupled haptic device was designed and built for this simulator. The haptic device can render 5.62 N and 190.05 N-mm of continuous force and torque respectively. In this work we have evaluated the haptic interface and developed a model to accurately describe the system behavior, to further incorporate into an impedance type controller for realistic haptic rendering in the VTEST(©).

Characterization of force and torque interactions during a simulated transgastric appendectomy procedure

We have developed an instrumented endoscope grip handle equipped with a six-axis load cell and measured forces and torques during a simulated transgastric natural orifice translumenal endoscopic surgery appendectomy procedure performed in an EASIE-R ex vivo simulator. The data were collected from ten participating surgeons of varying degrees of expertise which was analyzed to compute a set of six force and torque parameters for each coordinate axis for each of the nine tasks of the appendectomy procedure. The mean push/pull force was found to be 3.64 N (σ = 3.54 N) in the push direction and the mean torque was 3.3 N · mm (σ = 38.6 N · mm) in the counterclockwise direction about the push/pull axis. Most interestingly, the force and torque data about the nondominant x and z axes showed a statistically significant difference (p < 0.05) between the expert and novice groups for five of the nine tasks. These data may be useful in developing surgical platforms especially new haptic devices and simulation systems for emerging natural orifice procedures.

Role of transgastric natural orifice transluminal endoscopic surgery in the diagnosis of ascites of unknown origin (with videos)

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has been established in animal models and human studies.

OBJECTIVE

The aim of this study was to assess the feasibility and efficacy of applying transgastric NOTES to diagnose patients with ascites of unknown origin.

DESIGN

Prospective study.

SETTING

Two university and teaching hospitals.

PATIENTS

Patients with ascites of unknown origin.

INTERVENTIONS

Diagnostic transgastric NOTES.

MAIN OUTCOME MEASUREMENTS

Characteristic of ascites cases, conditions of the abdominal cavity, diagnostic accuracy, adverse events, and follow-up time.

RESULTS

Transgastric NOTES was performed successfully in 78 patients with ascites of unknown origin, and 72 cases (92.3%) were clearly diagnosed. They included malignant tumors (39 cases), tuberculous peritonitis (28 cases), chronic hepatic inflammation (3 cases), necrotizing lymphadenitis (1 case), and eosinophilic serositis of the small intestine (1 case). In addition, there were 6 nondiagnostic cases, and no severe adverse events were found.

LIMITATIONS

Nonrandomized control analysis.

CONCLUSION

Transgastric NOTES in combination with biopsy can elucidate the causes of ascites of unknown origin in the majority of cases. Therefore, it is a feasible and effective approach to access the peritoneal cavity and also a valuable modality to detect the cause of diseases with ascites of unknown origin.

A novel, new robotic platform for natural orifice distal pancreatectomy

Laparoendoscopic technology has revolutionized the practice of surgery; however, surgeons have not widely accepted laparoscopic techniques for pancreatic surgeries due to the complexity of the operation. Natural orifice transluminal endoscopic surgery (NOTES) offers a great new potential for pancreatic procedures, with early data showing benefits of reduced visible scarring and the potential for decreased wound infections, hernias, pain, and postoperative complications. However, there are significant limitations to the currently used flexible endoscopy tools, including a diminished visual field, spatial orientation and tissue manipulation issues, and 2-dimensional visual feedback. We have adopted a novel snake-like robot, the minimally invasive cardiac surgery (MICS) robot, which addresses these issues. In the current pilot study, the MICS robot was evaluated for transrectal distal pancreas exploration and resection in 2 nonsurvival porcine models. Abdominal navigation and accessing the pancreas was investigated in the first pig, and based on its success, pancreas resection was studied in pig 2. The MICS robot was successful in accessing and visualizing the right upper, left upper, and left lower quadrants of the abdomen in pig 1 and was able to perform a successful complex NOTES procedure with distal pancreas resection in pig 2, with only minimal laparoscopic retraction assistance. In conclusion, preliminary results showing the MICS robot in natural orifice distal pancreatectomy are positive. Enhancements to optics and instrumentation will help further increase the usability in pancreatic interventions. Future indications may include transgastric NOTES approaches, endoluminal procedures, and single-port applications.

EUS assisted transmural cholecystogastrostomy fistula creation as a bridge for endoscopic internal gallbladder therapy using a novel fully covered metal stent

Background

Laparoscopic cholecystectomy (LC) has become the “gold standard” for treating symptomatic gallstones. Innovative methods, such as a scarless therapeutic procedure through a natural orifice are being introduced, and include transgastric or transcolonic endoscopic cholecystectomy. However, before clinical implementation, instruments still need modification, and a more convenient treatment is still needed. The aim of this study was to evaluate the feasibility of endoscopic internal gallbladder therapy such as cholecystolithotomy in an animal survival model.

Methods

Four pigs underwent endoscopic-ultrasound (EUS)-guided cholecystogastrostomy and the placement of a novel covered mental stent. Four weeks later the stents were removed and an endoscope was advanced into the gallbladder via the fistula, and cholecystolithotomy was performed. Two weeks later the pigs were sacrificed, and the healing of the fistulas was assessed.

Results

EUS-guided cholecystogastrostomy with mental stent deployment was successfully performed in all the animals. Four weeks after the procedure, the fistulas had formed and all the stents were removed. Endoscopic cholecystolithotomy was performed through each fistula. All the animals survived until they were sacrificed 2 weeks later. The fistulas were found to be completely healed.

Conclusions

This study reports the first endoscopic transmural cholecystolithotomy after placement of a novel mental stent in an animal survival model.

"Down-to-Up" transanal NOTES Total mesorectal excision for rectal cancer: Preliminary series of 9 patients

BACKGROUND:

Applications for natural orifice translumenal endoscopic surgery (NOTES) to access the abdominal cavity have increased in recent years. Despite potential advantages of transanal and transcolonic NOTES for colorectal pathology, it has not been widely applied in the clinical setting. This study describes a series of nine patients for whom we performed transanal retrograde (“Down-to-Up”) total mesorectal excision for rectal cancer.

MATERIALS AND METHODS:

Under IRB approval, informed consent was obtained from each patient with rectal adenocarcinoma. Rectosigmoidectomy with total mesorectal excision was performed using low rectal translumenal access to the mesorectal fascia and subsequent dissection in a retrograde fashion. This was achieved using either a single port device or flexible colonoscope with endoscopic instrumentation and laparoscopic assistance. This was followed by transanal extraction of the specimen and hand-sewn anastomosis.

RESULTS:

Mean operative time was 311 min. Mean hospital stay was 7.56 days. Complications occurred in two patients, and consisted of one anastomotic leakage with reoperation and one intraoperative conversion to open surgery because of impossibility to dissect the specimen. TME specimen integrity was adequate in six patients.

CONCLUSION:

This series suggests that a retrograde mesorectal dissection via a NOTES technique is feasible in patients with rectal adenocarcinoma. This technique may act as a complimentary part of operative treatment for rectal cancer alongside other minimally invasive strategies. Long-term follow up will be needed to assess oncological results.

"Down-to-Up" transanal NOTES Total mesorectal excision for rectal cancer: Preliminary series of 9 patients

BACKGROUND

Applications for natural orifice translumenal endoscopic surgery (NOTES) to access the abdominal cavity have increased in recent years. Despite potential advantages of transanal and transcolonic NOTES for colorectal pathology, it has not been widely applied in the clinical setting. This study describes a series of nine patients for whom we performed transanal retrograde ("Down-to-Up") total mesorectal excision for rectal cancer.

MATERIALS AND METHODS

Under IRB approval, informed consent was obtained from each patient with rectal adenocarcinoma. Rectosigmoidectomy with total mesorectal excision was performed using low rectal translumenal access to the mesorectal fascia and subsequent dissection in a retrograde fashion. This was achieved using either a single port device or flexible colonoscope with endoscopic instrumentation and laparoscopic assistance. This was followed by transanal extraction of the specimen and hand-sewn anastomosis.

RESULTS

Mean operative time was 311 min. Mean hospital stay was 7.56 days. Complications occurred in two patients, and consisted of one anastomotic leakage with reoperation and one intraoperative conversion to open surgery because of impossibility to dissect the specimen. TME specimen integrity was adequate in six patients.

CONCLUSION

This series suggests that a retrograde mesorectal dissection via a NOTES technique is feasible in patients with rectal adenocarcinoma. This technique may act as a complimentary part of operative treatment for rectal cancer alongside other minimally invasive strategies. Long-term follow up will be needed to assess oncological results.

A novel method for endoscopic perforation management by using abdominal exploration and full-thickness sutured closure

BACKGROUND

Perforation of the GI tract during endoscopy can result in significant morbidity and mortality. Early recognition and immediate management of endoscopic perforation are essential to optimize outcome. Larger perforations, defects with complex geometry, and those complicated by leakage of luminal contents have traditionally required surgical management.

OBJECTIVE

To assess the feasibility of a new method for managing complex perforations that incorporates abdominal exploration and endoscopic sutured closure.

DESIGN

Case series.

SETTING

Tertiary care center.

PATIENTS

Two patients with large, complicated perforations and peritoneal contamination.

INTERVENTIONS

Endoscopic exploration of abdomen with angiocatheter placement under direct visualization, management of leaked luminal contents, and full-thickness sutured defect closure.

RESULTS

Endoscopic abdominal exploration through the perforation site allowed safe placement of an angiocatheter for management of pneumoperitoneum, inspection for injury that may warrant surgical management, and removal of leaked luminal contents. Endoscopic sutured closure allowed safe and robust perforation management. Repair of gastrojejunal anastomotic perforation required 2 sutures and 63 minutes. Repair of gastric perforation required 4 sutures and 48 minutes. Patients had successful endoscopic defect closure confirmed by an upper GI series and were discharged 1 day later.

LIMITATIONS

Report of a new method in 2 patients performed at tertiary care center.

CONCLUSIONS

We demonstrate successful management of complex perforations with peritoneal contamination by incorporating endoscopic exploration and sutured closure with standard treatment measures. Traditional practice would have directed these patients to surgical management, which introduces additional morbidity and cost. A means for safe and broad implementation of these techniques should be evaluated.

Flexible platforms for natural orifice transluminal and endoluminal surgery

The flexible endoscope is playing an increasingly pivotal role in minimally invasive transluminal and endoluminal surgery. Whilst the flexible nature of the platform is desirable in order to navigate through the abdominal cavity or through a lumen, there are a number of issues with using the platform for this purpose. The challenges associated with using flexible endoscopes such as a lack of triangulation of instruments and force transmission, which is often inadequate for endoscopic surgery are discussed in this review. As a result of these difficulties, a number of mechanically and robotically driven devices based upon the flexible endoscope are emerging. The design of these devices and potential problems are also reviewed. Finally, future robotic systems which are still in the development and validation stage are briefly discussed. The field of gastroenterology is diverging. The narrowing divide between minimally invasive and endoluminal surgery has led to a surge of innovative and novel devices which may in the future enable precise, seamless and scar less surgery.

Natural-orifice translumenal endoscopic surgery (NOTES): minimally invasive evolution or revolution?

Since the first animal experimental laparoscopy in 1902, minimal access techniques have revolutionized surgery. Using the natural orifice dates back to at least the second century when Soranus performed a vaginal hysterectomy. The main difference between traditional endolumenal surgery and the translumenal approach of natural-orifice translumenal endoscopic surgery (NOTES) is the intentional puncture of a healthy organ in NOTES to access a cavity or other organ. The aim of this review was to examine the past, present, and potential future role of NOTES in the context of other developments in minimal access surgery. NOTES is at an early stage in its development and a convincing benefit over laparoscopy has not been demonstrated. Concerns regarding complications, for example of viscerotomy closure, have limited the widespread uptake of pure NOTES. However, it is likely that technological advances for NOTES surgery will enhance conventional laparoscopic and endoscopic techniques.

Prophylactic mastectomy with immediate reconstruction combined with simultaneous laparoscopic salpingo-oophorectomy via a transmammary route: a novel surgical approach to female BRCA-mutation carriers

INTRODUCTION

Breast reconstruction with salpingo-oophorectomy can easily be performed in patients with genetic mutations increasing the risk for mammary and ovarian carcinoma. However, many patients are skeptical about having several surgeries, as they may result in additional anesthesiological risks as well as multiple visible scars. Therefore, the purpose of this study was to evaluate the feasibility of prophylactic mastectomy and breast reconstruction combined with simultaneous transmammary salpingo-oophorectomy for BRCA carriers.

MATERIALS AND METHODS

Of the six patients (1 %) who chose prophylactic mastectomy with salpingo-oophorectomy at our hospital four patients had BRCA-1 mutations, one patient had a BRCA-2 mutation and one patient had a family inheritance pattern with no mutations. All patients chose to reduce their risk for mammary and ovarian cancer by undergoing bilateral mastectomy and bilateral salpingo-oophorectomy. Prophylactic mastectomy with immediate reconstruction was performed, followed by bilateral salpingo-oophorectomy with a procedure that relies on transmammary access and reduces the number of necessary surgeries without compromising cosmetic results, surgical risks and operating time.

RESULT

The mean age of the patients was 46.7 ± 1.8 years (SD). The mean operative time was 190.2 ± 13.7 min. No complications were observed during the operations. The mean intra-operative loss of blood was 363.3 ± 77.9 ml. The operative method was successful in all six cases and was performed with no complications. All of the patients were satisfied with the cosmetic results.

CONCLUSION

In conclusion, prophylactic mastectomy and breast reconstruction combined with simultaneous laparoscopic salpingo-oophorectomy via transmammary access is feasible, easy to perform and provides an intriguing and novel approach to female BRCA carriers who desire operative prophylactic measures in one surgical session with no visible abdominal scars and no additional risks and complications.

Endoscopic closure of experimental iatrogenic gastric fundus perforation using over-the-scope clips in a surviving canine model

BACKGROUND AND AIM

To evaluate the effectiveness and outcomes of endoscopic closure of a gastric fundus perforation using over-the-scope clips (OTSCs) system in a surviving canine model.

METHODS

Gastric fundus perforations (20-mm diameter) were created by an endoscopic needle-knife in six dogs. The perforations then were closed by the OTSC system. Gastroscopy was performed to evaluate the postoperative perforation healing every week. The animals were sacrificed 4 weeks later to examine the possible intraperitoneal complications, and the healing of the perforation was examined histopathologically.

RESULTS

The gastric fundus perforations could primarily be closed using one OTSC in each experimental dog, and the mean time of the procedure was 17.3 ± 7.6 min (9-26 min). All animals survived without postoperative complications. The OTSC retention was observed in one dog at the end of 4 weeks, and the apparent foreign-body reaction was examined pathologically.

CONCLUSIONS

Our surviving animal study demonstrated that the OTSC clip system could reliably close gastric fundus perforations without complications.

NOTES for the management of an intra-abdominal abscess: transcolonic peritonoscopy and abscess drainage in a canine model

BACKGROUND

We studied natural orifice transcolonic drainage of intra-abdominal abscesses in a canine survival model to evaluate the difficulty of peritonoscopy and abscess drainage and the reliability of endoluminal colotomy closure.

METHODS

We placed a 7 cm nonsterile saline-filled latex balloon intra-abdominally to mimic or induce an abscess or inflammatory mass. Seven days later, we advanced a single-channel endoscope transanally into the sigmoid colon of the animal, made a colotomy and then advanced the endoscope intraperitoneally. We evacuated the identified abscess and placed a drain transabdominally. We closed the colotomy endoluminally with a tissue approximation system using 2 polypropylene sutures attached to metal T-bars. Two weeks later, we evaluated the colotomy closure at laparotomy.

RESULTS

We studied 12 dogs: 8 had subphrenic balloon implants and 4 had interbowel loop implants. Eleven survived and underwent transcolonic peritonoscopy; we identified the "abscess" in 9. The colotomy was successfully closed in 10 of 11 dogs. Although abscesses were easily identified, the overall difficulty of the peritonoscopy was moderate to severe. One dog required colotomy closure via laparotomy, while 9 had successful endoluminal closure. After colotomy closure, 8 animals survived for 2 weeks (study end point) without surgical complications, sepsis or localized abdominal infections. On postmortem examination, all closures were intact without any adjacent organ damage or procedure-related complications.

CONCLUSION

Natural orifice transluminal endoscopic surgery provides a novel alternative to treating intra-abdominal pathology. It is technically feasible to perform endoscopic transcolonic peritonoscopy and drainage of an intra-abdominal abscess with reliable closure of the colotomy in a canine experimental model.

A pilot study of natural orifice transanal endoscopic total mesorectal excision with laparoscopic assistance for rectal cancer

BACKGROUND

The objective of this pilot study was to evaluate the feasibility and safety of natural orifice endoscopic transanal total mesorectal excision (TME) with laparoscopic assistance in a cohort study of five patients with stage I and IIA rectal cancer.

METHODS

Five eligible patients with node-negative rectal cancer located 4-12 cm from the anal verge were enrolled in an IRB-approved pilot study. All patients underwent transanal endoscopic TME with laparoscopic assistance, hand-sewn coloanal anastomosis, and a diverting loop ileostomy. Primary and secondary end points included adequacy of the mesorectal excision and 30-day postoperative complications, respectively.

RESULTS

Between November 2011 and May 2012, three males and two females underwent transanal endoscopic TME with laparoscopic assistance. Patient mean age and BMI were 48.6 ± 9.8 years and 25.7 ± 2.3 kg/m(2), respectively. Tumors were located an average of 5.7 ± 2.4 cm from the anal verge and preoperatively staged as T1N0M0 (2), T2N0M0 (1), and T3N0M0 (2). Mean operative time was 274.6 ± 85.4 min with no intraoperative complications. Partial intersphincteric resection was performed in conjunction with transanal endoscopic TME in three patients. Pathologic examination of TME specimens demonstrated complete mesorectal excision in all cases with negative proximal, distal, and radial margins. Mean length of hospital stay was 5.2 ± 2.6 days and three minor complications occurred, including one ileus and two cases of transient urinary dysfunction. At a mean early follow-up of 5.4 ± 2.3 months, all patients remain disease-free.

CONCLUSIONS

In this pilot study of five patients with rectal cancer, transanal endoscopic TME with laparoscopic assistance is feasible and safe, and is a promising alternative to open and laparoscopic TME. Evaluation of long-term functional and oncologic outcomes of this approach is needed before widespread adoption can be recommended.

Robot-assisted transrectal hybrid natural orifice translumenal endoscopic surgery nephrectomy and adrenalectomy: initial investigation in a cadaver model

OBJECTIVE

To assess the feasibility of robotic transrectal hybrid natural orifice translumenal endoscopic surgery (NOTES) nephrectomy and adrenalectomy.

MATERIALS AND METHODS

A male cadaver was used for the present investigation and placed in lithotomy position. An 8- and 12-mm port was inserted through the same periumbilical skin incision. An incision was then created in the rectum 1 cm above the pectinate line, and a submucosal tunnel was developed, through which a robotic 8-mm port was inserted under vision. The cadaver was then placed in the right side up, flank position. The laparoscope and the right robot instrument were introduced through the umbilicus while the left robot instrument was introduced through the rectal port aiding the peri-umbilical ports in kidney and adrenal dissection. After completion of the nephrectomy, the kidney was placed in a specimen bag and extracted intact through the rectum. Closure of the rectal incision was accomplished extracorporeally using 2 suture layers.

RESULTS

Robotic transrectal hybrid NOTES nephrectomy and adrenalectomy were completed successfully. The total operative time was 145 minutes, of which the access and robotic docking required 20 minutes. Kidney dissection and hilar control was achieved within 60 minutes. Right adrenalectomy, specimen extraction, and rectal closure was completed in 15, 30, and 20 minutes, respectively.

CONCLUSION

We report the first investigation of a robot-assisted transrectal hybrid NOTES nephrectomy and adrenalectomy in a cadaver model to assess the range of motion and articulation of the robotic platform. Additional investigations in live animal model are needed to evaluate the safety of the transrectal approach.

Endolumenal colon occlusion device for transanal and transrectal surgery--a porcine feasibility study

PURPOSE

Although several studies have demonstrated the feasibility of transrectal natural orifice translumenal endoscopic surgery (NOTES), its clinical application has been hindered by concerns regarding potential infectious complications. The aim of this study was to evaluate the feasibility of a newly developed device for endolumenal colon occlusion (ColoShield) in an acute porcine model.

METHODS

The principle of the ColoShield device is based on two balloons, with negative pressure in between. The ColoShield device and a gauze tamponade as a control group were evaluated in a non-survival study on 16 pigs. The efficacy of the occlusion system in establishing a leak-proof pneumorectum and in sealing the colon from proximal (watertight sealing) was tested by a standardized study course. Finally, the colon/rectum was explanted for macroscopic and microscopic examination.

RESULTS

A 20-mmHg leak-proof pneumorectum over a period of 10 min could be achieved in seven of eight (87 %) animals with the ColoShield device and in none of eight (0 %) animals with gauze tamponade (p < 0.001). In the watertight sealing test, mean intracolonic pressures of 23.5 ± 18.1 (0-53) mmHg using the ColoShield device and 0 ± 1.1 (0-3) mmHg using gauze tamponade (p = 0.003) were documented proximal to the occlusion system before a leakage occurred. Macroscopic and histopathological examinations revealed no significant impairment of the colon specimen in either group.

CONCLUSIONS

ColoShield proved to be a safe and effective device for a reversible endolumenal colon occlusion. Further studies should evaluate its impact on procedural sterility during transrectal NOTES.

Is the transvaginal route appropriate for intra-abdominal NOTES procedures? Experience and follow-up of 222 cases

BACKGROUND

Since 2007, natural orifice transluminal endoscopic surgery (NOTES) has been applied in humans. We performed this prospective study to evaluate the transvaginal route in terms of risks, complication rate, and long-term side effects such as dyspareunia.

METHODS

From June 2007 to September 2011, we performed 222 transvaginal hybrid NOTES procedures: 220 transvaginal cholecystectomies (TVC) and 2 transvaginal appendectomies (TVA). All patients were asked to present to our associated gynecologists within 1 week for an examination. After at least 3 months, the patients were interviewed using a standard questionnaire.

RESULTS

All operations could be successfully performed in this technique except two cases, which were converted to conventional laparoscopic cholecystectomy. The only intraoperative complication was the puncture of the urine bladder. We observed two postoperative complications: one biliary fistula 3 days after TVC, and one abscess in the Douglas pouch 3 weeks after TVC. The gynecological examinations revealed no abnormalities. The interview (median postoperative time, 6 months) with a follow-up rate of 93 % revealed no pain in the pelvis, dyspareunia, or sexual dysfunction after TVC.

CONCLUSIONS

The transvaginal route is appropriate for NOTES procedures; there is only a minor and acceptable rate of intra- and postoperative morbidity.

Recent advances of natural orifice transluminal endoscopic surgery in urological surgery

Natural orifice transluminal endoscopic surgery designates a surgical procedure that utilizes one or more patent natural orifices of the body with the intention to puncture a hollow viscera in order to enter the abdominal cavity. First carried out at the beginning of the 2000s in experimental models, it can be considered the natural evolution of laparoscopy towards the ideal of scarless surgery, as the avoidance of a large abdominal scar is associated with better cosmetic results and better recovery. However, the technology currently available does not allow the performance of complete pure natural orifice transluminal endoscopic surgery procedures. The surgical tools used are not specially designed for this approach, so difficulties in retracting organs, bleeding control and clashing of instruments are the main obstacle surgeons face. For this reason, the current available technique is the so-called hybrid approach, where a natural orifice approach is combined with some abdominal trocars, using the natural orifice as the exit door for the specimen removal. As not many comparative studies have been published evaluating the advantages of natural orifice transluminal endoscopic surgery in front of traditional laparoscopic surgery, a review of the history of natural orifice transluminal endoscopic surgery, and an assessment of the available evidence of this technique regarding renal and urological pelvic surgery are performed in this article.

Laparoscopic assisted transvaginal cholecystectomy: single centre preliminary experience

BACKGROUND

Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a new approach that allows abdominal surgery to be performed through a natural orifice such as the oral cavity, vagina or rectum. We present our preliminary experience of laparoscopic assisted transvaginal cholecystectomy (LATC).

METHODS

Women affected by cholelithiasis, age below 65 years, BMI under 30, ASA I or II, previous full-term pregnancies, and without previous abdominal surgery underwent LATC. Patients' biographic data, operative time, intraoperative and postoperative complications were collected.

RESULTS

We performed 21 LATCs. Median operative time was 58 min. There were no intraoperative complications. The postoperative course was uneventful in all patients. At 1 year there were no complications and no impaired sexual activity.

CONCLUSIONS

The results of NOTES are promising, but currently only hybrid NOTES can be safely performed. LATC seems to guarantee better cosmetic results, less postoperative pain, faster mobilization and shorter hospitalization than laparoscopic cholecystectomy.

Feasibility of transrectal hybrid natural orifice transluminal endoscopic surgery (NOTES) nephrectomy in the cadaveric model

OBJECTIVE

To examine feasibility of transrectal hybrid natural orifice transluminal endoscopic surgery (NOTES) nephrectomy in human cadavers in the evolution of this technique, as transrectal hybrid NOTES nephrectomy has been demonstrated in the porcine model.

METHODS

Four hybrid transrectal NOTES nephrectomies were performed on 4 cadavers (3 female/1 male, 2 right/2 left). Pneumoperitoneum was created by periumbilical 12-mm trocar, through which a laparoscope was advanced to obtain intra-abdominal visualization. A 4-cm horizontal incision was made 2-cm above the dentate line and a submucosal tunnel was created in the posterior rectal wall/presacral space. A dual-channel gastroscope was advanced through the submucosal tunnel and retroperitoneum to the level of the kidney using air insufflation. A peritoneal window was created and renal mobilization was completed. A transumbilically applied laparoscopic 45-mm stapler was used to transect the ureter and renal hilum. A specimen entrapment bag was deployed transrectally for specimen extraction, followed by transrectal incision closure.

RESULTS

Transrectal NOTES nephrectomy was successfully performed in all cases, with intact specimen extraction. Median weight was 77 kg (range 74-85 kg); median body mass index (BMI) was 30.1 kg/m(2) (range 25.6-31.2 kg/m(2)). Mean operative time was 175 minutes (range 150-210 minutes). Median transrectal access time was 36 minutes (range 24-47 minutes). Median dimensions of removed kidneys were length 11.2 cm (range 10-12 cm), width 5 cm (range 4.5-6 cm), and thickness 3.8 cm (range 3-4.5 cm).

CONCLUSION

Transrectal hybrid NOTES nephrectomy in the cadaver model is feasible with intact specimen extraction and acceptable operative times. Preclinical survival studies are requisite to assess sterility and complications. This approach may be an alternative to transvaginal access.

Gastric surgery and notes

Rather than being an end point in and of itself, NOTES offers an approach that encompasses the potential use of a natural orifice in conjunction with flexible instruments as a less invasive and more cosmetically appealing method of performing certain surgical procedures. Gastric surgery through natural orifices is one of the cutting-edge procedures in the evolving field of NOTES. The potential indications for NOTES involve a wide spectrum of upper gastrointestinal diseases, including achalasia, reflux disease, submucosal tumors, cancer, and morbid obesity. Although NOTES is becoming more widely used, most studies still involve only small numbers of patients, and the design of larger series and comparative trials to evaluate the early indications and results of NOTES is needed.

An ex vivo bacteriologic study comparing antiseptic techniques for natural orifice translumenal endoscopic surgery (NOTES) via the gastrointestinal tract

BACKGROUND

NOTES via the gastrointestinal tract raises the specter of intra-peritoneal infection. Various anti-microbial techniques have been employed in animal and human survival studies, including saline lavage, intravenous and topical antibiotics, and povidone-iodine, although there is a paucity of data regarding their general effectiveness.

AIM

To assess the effectiveness of existing sterilization techniques for NOTES by quantifying and speciating colony-forming units (CFUs) before and after treatment.

DESIGN

Ex vivo animal studies; bacteriological study.

METHODS

Stomachs and distal colons were harvested en bloc from ten fasted adult white pigs following euthanasia. Half received cefazolin 1 g intravenously prior to killing. Multiple tissue samples were obtained from each resected organ. Each tissue sample was then assigned to one of five treatment arms: (1) normal saline, (2) Betadine, (3) cefazolin/metronidazole suspension, (4) chlorhexidine, (5) no treatment. Fifteen samples were used per arm. After treatment, the mucosal surface of each sample was swabbed and inoculated in normal saline, followed by serial dilutions, which were then plated onto sheep's blood agar plates and incubated under aerobic and anaerobic conditions. CFUs were quantified and speciated.

RESULTS

Median bacterial density was estimated to be 8.0 × 10(5) CFUs/ml (stomach) and 1.9 × 10(6) CFUs/ml (colon). The predominant organisms were Escherichia coli (stomach) and both E. coli and Enterococcus sp. (colon). Saline and antibiotic suspension lavages caused a 1-log reduction in stomach and colon. Betadine/chlorhexidine lavage resulted in a 4-log reduction. Intravenous antibiotics alone resulted in a 4-log reduction. Combining intravenous antibiotics and either Betadine or chlorhexidine decreased counts to the 10(1) level. By Kruskal-Wallis method, differences were statistically significant (p = 0.001).

CONCLUSIONS

The use of intravenous antibiotics in addition to topical Betadine or chlorhexidine effectively reduced microbial burden in both gastric and colonic mucosa in this porcine model to the 10(1) level.

Perirectal Oncologic Gateway to Retroperitoneal Endoscopic Single-Site Surgery (PROGRESSS): a feasibility study for a new NOTES approach in a swine model

INTRODUCTION

A transanal, posterior, retrorectal approach has been demonstrated as a feasible natural orifice transluminal endoscopic surgery (NOTES) total mesorectal excision (TME) procedure. The aim was to assess the feasibility of a transrectal approach with a completely retroperitoneal mobilization of the left colon and mesenteric vessels in an acute porcine model.

MATERIALS AND METHODS

Eight pigs were used. A purse-string suture was made 3 cm above the anal sphincter. Next, the retroperitoneal, perirectal space was entered with an endoscope through a single (or twin) anterior lateral, transrectal viscerotomy. A retroperitoneal tunnel was created using pneumodissection or endoscopically guided dissection to the inferior mesenteric artery (IMA). The IMA was skeletonized and lymph nodes retrieved using the IsisScope or other instruments. The IMA was divided with the Ligasure, clips, or ligature performed with the IsisScope. The rectum was dissected transanally in the "Holy" plane. After achieving mobilization using a completely retroperitoneal approach, the peritoneal attachments were then divided and the rectosigmoid specimen exteriorized through the anus. An explorative laparoscopy was then performed to evaluate the quality of the mobilization.

RESULTS

The procedure was successfully completed and the IMA correctly identified and ligated in all cases. In all but one case, no further mobilization was possible, even by a laparoscopic approach.

CONCLUSIONS

Perirectal oncologic gateway to retroperitoneal endoscopic single-site surgery for left-sided colonic resections using both flexible and rigid surgical endoscopic platforms was feasible and reproducible in an acute porcine model. This technique might represent a step toward pure NOTES left-sided colorectal procedures.

New laser soldering-based closures: a promising method in natural orifice transluminal endoscopic surgery

BACKGROUND

Complete closure of gastrotomy is the linchpin of safe natural orifice transgastric endoscopic surgery.

OBJECTIVE

To evaluate feasibility and efficacy of a new method of gastrotomy closure by using a sutureless laser tissue-soldering (LTS) technique in an ex vivo porcine stomach.

DESIGN

In vitro experiment.

SETTING

Experimental laboratory.

INTERVENTIONS

Histological analysis and internal and external liquid pressure with and without hydrochloric acid exposure were determined comparing gastrotomy closure with LTS and with hand-sewn surgical sutures.

MAIN OUTCOME MEASUREMENTS

Comparison of LTS and hand-sewn surgical gastrotomy closure. The primary outcome parameter was the internal leak pressure. Secondary parameters were the difference between internal and external leak pressures, the impact of an acid environment on the device, histological changes, and feasibility of endoscopic placement.

RESULTS

The internal liquid leak pressure after LTS was almost twice as high as after hand-sewn surgical closure (416 ± 53 mm Hg vs 229 ± 99 mm Hg; P = .01). The internal leak pressure (416 ± 53 mm Hg) after LTS was higher than the external leak pressure (154 ± 46 mm Hg; P < .0001). An acidic environment did not affect leak pressure after LTS. Endoscopic LTS closure was feasible in all experiments. Histopathology revealed only slight alterations beneath the soldering plug.

LIMITATIONS

In vitro experiments.

CONCLUSIONS

Leak pressure after LTS closure of gastrotomy is higher than after hand-sewn surgical closure. LTS is a promising technique for closure of gastrotomies and iatrogenic perforations. Further experiments, in particular survival studies, are mandatory.

A technical review of flexible endoscopic multitasking platforms

BACKGROUND

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform.

METHODS

Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed.

RESULTS

Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human.

CONCLUSION

Alternative forms of instrument actuation, camera control and master console ergonomics should be explored to improve instrument precision, sphere of action, size and minimize assistance required.

Current progress on natural orifice transluminal endoscopic surgery (NOTES)

Natural orifice transluminal endoscopic surgery (NOTES) has received considerable interest in recent years as a novel surgical technique. Here, we aim to review the current progress on NOTES, particularly focusing on the advantages and complications related to NOTES, the recent advances of surgical approaches, new instruments for closure of the natural orifice incision, and the newly developed platform for NOTES. Finally, we make a prediction of the conceivable applications of NOTES on human subjects.

Efficacy and safety of transgastric closure in natural orifice transluminal endoscopic surgery using the OTSC system and T-bar sutures: a survival study in a porcine model

BACKGROUND

In natural orifice transluminal endoscopic surgery (NOTES), procedures are performed with an endoscope passed through a natural orifice. One of the most important factors that will determine the future of transgastric NOTES is obtaining a reliable closure of the access site. The aim of this study was to determine the efficacy and safety of transgastric closure using the over-the-scope clip (OTSC) system or T-bar sutures.

METHODS

We performed a survival study that included 15 pigs. A standardized transgastric approach to the peritoneal cavity and a peritoneoscopy were performed. The gastrotomy was closed using the OTSC system or T-bar sutures. The gastrotomy closure was tested for leaks with the methylene blue test. All animals were observed for 2 weeks before they were sacrificed and necropsy was performed. Histopathological examination of tissue samples retrieved from the access sites was performed.

RESULTS

There were no perioperative complications. The methylene blue test did not demonstrate any leakage of fluid. Necropsy after 2 weeks confirmed completeness of gastric closure in all animals with full-thickness healing and no spillage of gastric contents into the peritoneal cavity. No differences between the OTSC system and T-bar sutures were observed.

CONCLUSION

We observed no differences between the efficacy and safety of the OTSC system and those of T-bar sutures used in closing gastric incisions in NOTES. Both methods are safe and effective.

Natural orifice transesophageal endoscopic surgery: state of the art

The main goal of Natural Orifice Transluminal Endoscopic Surgery (NOTES) is performing surgery avoiding skin incisions. Theoretical advantages of NOTES include decreased postoperative pain, reduction/elimination of general anesthesia, improved cosmetic outcomes, elimination of skin incision-related complications such as wound infections and hernias, and increased overall patient satisfaction. Although various forms of port creation to accomplish thoracic NOTES procedures have been proposed, transesophageal NOTES has been shown to be the most reliable one. The evolution of endoscopic submucosal transesophageal access resulted in the development of per-oral endoscopic myotomy (POEM), which had a fast transition to clinical practice. The authors present a review of the current state of the art concerning transesophageal NOTES, looking at its potential for diagnostic and therapeutic interventions as well as the hurdles yet to be overcome.

Infection during natural orifice transluminal endoscopic surgery peritoneoscopy: a randomized comparative study in a survival porcine model

BACKGROUND

Infection in natural orifice transluminal endoscopic surgery (NOTES) remains controversial.

OBJECTIVE

To estimate the frequency of infection during NOTES peritoneoscopy with different routes of access and to compare with laparoscopy.

DESIGN

Prospective randomized controlled study (Canadian Classification type I).

METHODS

Forty female pigs were randomly assigned to 3 NOTES (transgastric, transrectal, and transvaginal) and laparoscopic groups. Antiseptic technique was used for NOTES, whereas laparoscopy was performed in a sterile environment. Preoperative and postoperative intravenous antibiotics were administered. Closure of the transluminal access site was performed in all animals. Peritoneal fluid was collected for culture at the end of surgery and at necropsy at day 14.

RESULTS

Thirty-nine peritoneoscopies were successfully completed. Necropsy confirmed complete healing of NOTES incisions, but 2 animals in the laparoscopy group had small abscesses in the abdominal incisions. There were no statistical differences in the presence of peritoneal adhesions. Positive culture results were seen in all groups at the end of the procedure and in all animals at necropsy, but this did not lead to clinical signs of gross infection. The most common organisms that colonized the peritoneum were gram-positive cocci and gram-negative bacilli from the normal swine gastrointestinal flora.

LIMITATIONS

Animal model and small sample size.

CONCLUSIONS

In these small series of animals and with the careful lavage and preparation used, NOTES appeared to be comparable to laparoscopy in terms of peritoneal contamination and clinical infection. Despite the adherence to a strict antiseptic protocol, peritoneal contamination occurs but does not lead to septic complications in the swine.

Transvaginal cholecystectomy without laparoscopic support using prototype flexible endoscopic instruments in a porcine model

BACKGROUND

Transvaginal cholecystectomy with laparoscopic assistance has been performed safely in humans. The next goal was to develop a natural orifice transluminal endoscopic surgery (NOTES) technique to perform cholecystectomy without laparoscopic instruments using one flexible endoscope and flexible accessories. The aim of the study was to test the feasibility of the procedure in a survival porcine model.

METHODS

Cholecystectomies were attempted in five 88-130-lb. pigs with a planned 2-week survival. Prototype flexible instruments (NOTES Toolbox, Ethicon Endo-Surgery, Inc.) were used to aid in access, dissection, and removal of the gallbladder via the transvaginal route.

RESULTS

Cholecystectomy could be completed without abdominal incision using prototype instruments in four out of five pigs. The cystic duct could be exposed with a flexible hook knife and clips applied. The steerable trocar improved stability and the precision of the dissection. The critical view was established in all five pigs. Dissection of the gallbladder off the liver bed was imprecise resulting in gallbladder perforation in all pigs and liver hemorrhage in two. At necropsy, all clips on the cystic duct were secure and no bile leak, bowel injury, or adhesions were present.

CONCLUSIONS

NOTES cholecystectomy without laparoscopic support is feasible but challenging using prototype flexible endoscopic devices. A prototype clip applier was effective in controlling the cystic duct. Further improvements in instrument design to ensure precision and safety are needed before flexible devices should be used for pure NOTES procedures in humans.

Intramural acellular porcine dermal matrix (APDM)-assisted gastrotomy closure for natural orifice transluminal endoscopic surgery (NOTES)

BACKGROUND

A highly reliable and safe means of gastric closure for natural orifice transluminal endoscopic surgery (NOTES) has yet to be developed. The authors have previously described the self-approximating transluminal access technique (STAT) as a means for gastrotomy closure in transgastric surgery. It has yet to be determined whether biologic mesh can be utilized in facilitating gastrotomy closure via STAT. The aim of this study was to determine the feasibility of implanting an acellular porcine dermal matrix (LifeCell) into the STAT tunnel and investigate whether it will become incorporated into the submucosal plane of the STAT tunnel.

METHODS

Five pigs underwent transgastric left uterine horn resection utilizing STAT. For closure, the acellular porcine dermal matrix was implanted within the submucosal plane, occluding the seromuscular incision. The mucosal incision was then closed over the matrix with endoscopically placed clips. Necropsy was performed after a 3 week survival period. Histopathological evaluation of the tunnel and matrix was performed.

RESULTS

The matrix was successfully implanted in all five animals. Average OR time was 151 ± 68 min. Average time to anchor and embed the matrix within the tunnel was 4 ± 1 and 9 ± 12 min, respectively. There was one duodenal perforation related to a balloon occlusion device. Postoperative course was unremarkable; the average weight gain at 3 weeks was 22 ± 5 lbs. On necropsy, one animal had some protrusion of the matrix at the serotomy, with adhesions to small bowel and liver. Histopathology revealed one clinically insignificant microabscess but otherwise demonstrated local inflammation and fibrovascular ingrowth into the matrix.

CONCLUSIONS

The porcine dermal matrix can be successfully implanted within the gastric submucosal plane and evidence of incorporation into the gastric wall by 3 weeks was demonstrated.

Intraoperative NOTES endosonography and identification of mock hepatic lesions

PURPOSE

Intraoperative ultrasound is commonly used during standard transabdominal surgery. The feasibility of endoscopic ultrasound (EUS) through Natural Orifice Translumenal Endoscopic Surgery (NOTES) for identification of abdominal lesions with a flexible echoendoscope has not been studied.

AIM

To test the feasibility of NOTES-EUS for abdominal exploration and identification of mock hepatic lesions.

METHODS

Five pigs underwent transvaginal or transcolonic NOTES and endosonographic exploration. In 3 anesthetized pigs, mock hepatic lesions were created and NOTES-EUS was then performed to identify these mock lesions. Necropsy was performed in all cases.

RESULTS

All target organs were consistently identified by NOTES-EUS in all animals. Mock hepatic lesions were successfully created in 3 animals and were able to be located by NOTES-EUS. No complications were observed at necropsy.

CONCLUSIONS

Abdominal exploration and localization of mock lesions by NOTES-EUS is technically feasible. As natural orifice surgery evolves, intraoperative NOTES-EUS would be an essential addition to the NOTES armamentarium.