An innovative, safe and sterile sigmoid access (ISSA) for NOTES

MIEO: a micro-invasive endoscopic operation port system for transluminal interventions-an acute and survival porcine study

Background

A reliable and sterile access through the intestinal wall to ease flexible endoscopic transluminal interventions is still appealing but lacks a suitable port system.

Methods

In a granted industry cooperation, we developed the MIEO-Port, a flexible three components overtube system that provides a temporary hermetic sealing of the intestinal wall to allow endoscopic disinfection and manipulation to gain access to the abdominal cavity. The port features an innovative head part which allows for coupling the port to the intestinal wall by vacuum suction and for controlled jetting the isolated intestinal surface with a disinfectant. The device was tested in vivo in 6 pigs for acute and long-term usability. All animal tests were approved by the local ethics committee.

Results

In the acute experiment, the port system supported sealed endoscopic mucosa resection and transluminal cholecystectomy. In the survival study on 5 animals, the MIEO-Port proved its reliability after transcolonic peritoneoscopy. In one animal, a port dislocation occurred after extensive retroperitoneal preparation, one animal revealed bacterial contamination at necropsy; however, all animals showed a favourable course over ten days and offered no signs of peritonitis or abscedation during post-mortem examination.

Discussion

To the best of our knowledge, the MIEO-Port system is the first device to provide a reliable and sterile flexible access to the peritoneal cavity that can be used throughout the entire gastrointestinal tract regardless of the access route and which combines hermetic sealing with local sterilization. Further studies are warranted.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07518-3) contains supplementary material, which is available to authorized users.

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.

Endoscopic resection of the pancreatic tail and subsequent wound healing mechanisms in a porcine model

BACKGROUND

Laparoscopic resection of the pancreatic body and tail is the predominant methodology to remove lesions in these locations; its safety and surgical planning are relatively mature, but it remains a complex and high-precision surgical operation, requiring abundant experience and skills in laparoscopic surgery, with a 10% rate of complications.

AIM

To verify the feasibility and safety, as well as to examine the complications of endoscopic pancreatectomy and healing mechanisms of pancreatic wounds after endoscopic resection.

METHODS

Transgastric endoscopic resections of varying sizes of pancreases were performed in 15 healthy Bama miniature pigs. The technical success rate, the incidence of serious complications, and the survival of the animals were studied. The healing of the wounds was evaluated by sacrificing the animals at various time points. Finally, the expression of transforming growth factor-β1 and Smad3/Smad7 in the surgical site was examined by immunohistochemistry to explore the role of these factors in wound healing of the pancreas.

RESULTS

Partial and total resections were successfully performed in two groups of animals, respectively. The technical success rate and the survival rate of the pigs were both 100%. We obtained 12 pancreatic tissue samples by endoscopic resection. The pancreatic wounds were closed with metal clips in one group and the wounds healed well by forming scars. There was a small amount of pancreatic leakage in the other group, but it can be fully encapsulated. The level of transforming growth factor-β1 (TGF-β1) in the wounds increased during the inflammatory and fibrous hyperplasia phases, and decreased in the scar phase. The expression of Smad3 paralleled that of TGF-β1, while the expression of Smad7 had an inverse relationship with the expression of TGF-β1.

CONCLUSION

Purely transgastric endoscopic resection of the pancreas is a safe, effective, and feasible procedure, but the incidence of pancreatic leakage in total pancreatic tail resection is high. The expression of TGF-β1 and Smad3/Samd7 is related to the progression of pancreatic wound healing.

Transcolonic Perirectal NOTES Access (PNA): A feasibility study with survival in swine model

Transrectal access still has some unsolved issues such as spatial orientation, infection, access and site closure. This study presents a simple technique to perform transcolonic access with survival in a swine model series. A new technique for NOTES perirectal access to perform retroperitoneoscopy, peritoneoscopy, liver and lymphnode biopsies was performed in 6 pigs, using Totally NOTES technique. The specimens were extracted transanally. The flexible endoscope was inserted through a posterior transmural incision and the retrorectal space. Cultures of bacteria were documented for the retroperitoneal space and intra abdominal cavity after 14 days. Rectal site was closed using non-absorbable sutures. There was no bowel cleansing, nor preoperative fasting. The procedures were performed in 6 pigs through transcolonic natural orifice access using available endoscopic flexible instruments. All animals survived 14 days without complications, and cultures were negative. Histopathologic examination of the rectal closure site showed adequate healing of suture line and no micro abscesses. The results of feasibility and safety of experimental Transcolonic NOTES potentially brings new frontiers and future wider applications for minimally invasive surgery. The treatment of colorectal, abdominal and retroperitoneal diseases through a flexible Perirectal NOTES Access (PNA) is a promising new approach.

Scarless surgery for a huge liver cyst: A case report

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Fenestration is the definitive treatment for symptomatic/complicated liver cysts.

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NOTES, which has been reported recently, enables surgery without scars.

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Multiple clinical and technological barriers impede further progress with NOTES.

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Our safe and unique method enables minimally invasive surgery with small incisions.

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This “scarless surgery” is expected to yield some clinical benefits.

Introduction

Symptomatic or complicated liver cysts sometimes require surgical intervention and laparoscopic fenestration is the definitive treatment for these cysts. We performed minimally invasive surgery, hybrid natural orifice transluminal endoscopic surgery (NOTES) without scarring, for a huge liver cyst.

Presentation of case

An 82-year-old female presented with a month-long history of right upper abdominal pain. We diagnosed her condition as a huge liver cyst by morphological studies. She denied any history of abdominal trauma. Her serum CEA and CA19-9 were normal and a serum echinococcus serologic test was negative. Laparoscopic fenestration, using a hybrid NOTES procedure via a transvaginal approach, was performed for a huge liver cyst because we anticipated difficulty with an umbilical approach, such as single incision laparoscopic surgery (SILS). Her post-operative course was uneventful and she was discharged from our hospital three days after surgery. Pain killers were not required during and after hospitalization. No recurrence of the liver cyst or bulging was detected by clinical examination two years later.

Discussion

A recent trend of laparoscopic procedure has been towards minimizing the number of incisions to achieve less invasiveness. This hybrid NOTES, with a small incision for abdominal access, along with vaginal access, enabled painless operation for a huge liver cyst.

Conclusion

We report a huge liver cyst treated by hybrid NOTES. This approach is safe, less invasive, and may be the first choice for a huge liver cyst.

Pure Natural Orifice Transluminal Endoscopic Surgery (NOTES) with a new elongated, curved Transanal Endoscopic Operation (TEO) device for rectosigmoid resection: a survival study in a porcine model

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has seen considerable new developments in its evolution to a platform for rectal and sigmoid resection, but to date no true single NOTES procedure has been convincing. This study investigates the safety and feasibility of a further developed transanal NOTES platform for single-access NOTES rectosigmoid resection.

METHODS

Ten large female pigs, mean weight 99.3 kg [standard deviation (SD) 7 kg, range 85.1-112.6 kg], underwent transanal rectosigmoid resection. Five animals were included in an acute study group with immediate postoperative euthanization. A second group included five animals in a survival study. Transanal rectosigmoid resections were performed with an elongated and curved transanal endoscopic operation (TEO) device. Coloanal anastomosis was performed using the transanal circular stapler technique. Survival follow-up was at 7 and 28 days via colonoscopy under sedation.

RESULTS

Single-access NOTES transanal rectosigmoid resection with coloanal anastomosis was performed in nine out of ten female pigs. Mean length of rectosigmoid specimens exteriorized was 18.7 cm (SD 2.9 cm, range 14-23 cm). Mean operating time was 124 min (SD 35.7 min, range 70-166 min). Within the survival group, no complications occurred during the monitoring phase. In one case, there was ascites and colitis at necropsy as well as fibrosis at the anastomosis site.

CONCLUSIONS

Pure transanal rectosigmoid resection is a feasible procedure. The approach via a single transanal access is demanding but viable with the elongated and curved TEO device. The newly developed scope offers an excellent view of the area cephalad to the promontory.

The quest for precision in transanal total mesorectal excision

Transanal total mesorectal excision (TME) is an emerging minimally invasive approach to rectal cancer, with encouraging preliminary results. However, the new surgical anatomy of the bottom-up approach complicates surgical understanding and increases the risks of inadvertent injuries to crucial anatomical structures, including nerves. Key elements to improve the safety and stimulate interest in such a complex technique might be robotics and image guidance, to enhance the level of precision. In this editorial, some of the technologies that could be used for precision TME are outlined, in light of the experience of our Institute for Image-Guided Surgery.

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.

Inventing the future of surgery

Surgical innovation relies on patient safety and quality of life, which require a drastic iatrogenic impact reduction. A parallel development toward less invasive approaches has occurred in the field of surgery, interventional radiology, and endoscopy. Minimally invasive techniques provide unquestionable benefits to patients in terms of postoperative outcome. However, those techniques are not intuitive, and extensive training is required to overcome the inherent challenges and to be proficient and consequently to achieve a steep learning curve. Technologies have been developed by computer science and robotics departments, which might improve minimally invasive techniques. A new concept of cyber therapies is emerging through the development of computer and robotic sciences aiming at human-machine integration. Additionally, the convergence of surgery, endoscopy, and interventional radiology toward a hybrid therapeutic modality, namely image-guided minimally invasive procedures, holds promises insofar as they could well maximize benefits in terms of efficacy and iatrogenic impact. In the present manuscript, the mainstays of these new paradigm developments are briefly outlined in light of our experience and vision of the future.

Next step in minimally invasive surgery: hybrid image-guided surgery

Surgery, interventional radiology, and advanced endoscopy have all developed minimally invasive techniques to effectively treat a variety of diseases with positive impact on patients' postoperative outcomes. However, those techniques are challenging and require extensive training. Robotics and computer sciences can help facilitate minimally invasive approaches. Furthermore, surgery, advanced endoscopy, and interventional radiology could converge towards a new hybrid specialty, hybrid image-guided minimally invasive therapies, in which the three fundamental disciplines could complement one another to maximize the positive effects and reduce the iatrogenic footprint on patients. The present manuscript describes the fundamental steps of this new paradigm shift in surgical therapies that, in our opinion, will be the next revolutionary step in minimally invasive approaches.

"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.

Comparison of transrectal and transvaginal hybrid natural orifice transluminal endoscopic surgery partial nephrectomy in the porcine model

OBJECTIVE

To compare the feasibility of porcine transrectal (TR) and transvaginal (TV) hybrid natural orifice transluminal endoscopic surgery (NOTES) partial nephrectomy (PN), as NOTES nephrectomy has recently been performed in the porcine model.

MATERIALS AND METHODS

A total of 10 female pigs (weight 45 kg) underwent TR (n = 5) or TV (n = 5) NOTES PN. The pneumoperitoneum was created by a periumbilical 12-mm trocar, through which a laparoscope was advanced for intra-abdominal visualization. For TV-NOTES PN, a gastroscope was used to obtain TV peritoneal access. For TR-NOTES PN, a horizontal incision was made 2 cm above the dentate line, and a submucosal tunnel was created in the posterior rectal wall. The gastroscope was advanced through the submucosal tunnel and retroperitoneum to the kidney, and a peritoneal window was created. For both TR- and TV-NOTES PN, the gastroscope was exchanged for the SPIDER Surgical System. Flexible dissecting instruments and hook cautery introduced through the SPIDER Surgical System were used to mobilize the kidney. A harmonic scalpel introduced periumbilically was used to excise a portion of the lower pole. LAPRA-TY-secured sutured renorrhaphy was performed, followed by TR or TV specimen extraction.

RESULTS

TR- and TV-NOTES PN was successfully performed in all 10 pigs. A comparison of TR- and TV-NOTES PN revealed no significant differences in the mean access time (29.2 vs 29.6 minutes, P = .944), operative time (196.0 vs 183.0 minutes, P = .631), and estimated blood loss (59.0 vs 54.0 mL, P = .861). Necropsy did not demonstrate abdominal injuries.

CONCLUSION

We have demonstrated proof-of-principle for TR and TV-NOTES PN in swine, with comparable perioperative parameters. Preclinical survival studies are requisite to assess the potential of TR-NOTES as an alternative to TV-NOTES.

Euro-NOTES Status Paper: from the concept to clinical practice

BACKGROUND

The concept of natural orifice transluminal endoscopic surgery (NOTES) consists of the reduction of access trauma by using a natural orifice access to the intra-abdominal cavity. This could possibly lead to less postoperative pain, quicker recovery from surgery, fewer postoperative complications, fewer wound infections, and fewer long-term problems such as hernias. The Euro-NOTES Foundation has organized yearly meetings to work on this concept to bring it safely into clinical practice. The aim of this Euro-NOTES status update is to assess the yearly scientific working group reports and provide an overview on the current clinical practice of NOTES procedures.

METHODS

After the Euro-NOTES meeting 2011 in Frankfurt, Germany, an analysis was started regarding the most important topics of the European working groups. All prospectively documented information was gathered from Euro-NOTES and D-NOTES working groups from 2007 to 2011. The top five topics were analyzed.

RESULTS

The statements of the working group activities demonstrate the growing information and changing insights. The most important selected topics were infection issue, peritoneal access, education and training, platforms and new technology, closure, suture, and anastomosis. The focus on research topics changed over time. The principle of hybrid access has overcome the technical and safety limitations of pure NOTES. Currently the following NOTES access routes are established for several indications: transvaginal access for cholecystectomy, appendectomy and colon resections; transesophageal access for myotomy; transgastric access for full-thickness small-tumor resections; and transanal/transcolonic access for rectal and colon resections.

CONCLUSIONS

NOTES and hybrid NOTES techniques have emerged for all natural orifices and were introduced into clinical practice with a good safety record. There are different indications for different natural orifices. Each technique has been optimized for the purpose of finding a safe and realistic solution to perform the procedure according to the specific indication.

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.

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.

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.

Transanal hybrid colon resection: from laparoscopy to NOTES

BACKGROUND

Reducing access size and trauma are important issues in natural orifice transluminal endoscopic surgery (NOTES). The combination of experience with laparoscopic colorectal surgery and transanal endoscopic microsurgery has helped in the use of the transanal approach as a realistic option of NOTES techniques to introduce transanal hybrid laparoscopic-assisted colon resection into clinical practice. The purpose of this study was to assess the clinical introduction of transanal hybrid colon resection in terms of feasibility and patient safety.

METHODS

Patients with pelvic floor disorders, prolapse, and slow-transit constipation in whom a colon resection was indicated were recruited. Patients were followed prospectively with a postoperative well-being score, a pain score, and a quality-of-life score. All complications were prospectively documented. The essential change was the reduction of the number and size of ports by using the transanal route. A camera and two 5-mm ports for grasping forceps and delivering ultrasonic energy were the laparoscopic components. All tasks requiring a port diameter of >5 mm were applied via the transanal route, such as positioning of the proximal stapler anvil, application of linear stapling for resection, specimen retrieval, stapler anastomosis, and closing the bowel.

RESULTS

Fifteen patients with benign colorectal disease underwent transanal hybrid colon resection, and 11 had additional rectopexy. All patients were women with a mean age of 61 (range, 28-86) years and a body mass index of 26 kg/m(2). One patient was converted to full laparoscopy. One complication--bleeding that required no reintervention--was recorded. The procedure lasted a mean of 131 (range, 55-184) min. The Gastrointestinal Quality of Life Index was 96 before surgery and 117 after surgery.

CONCLUSIONS

From this initial experience, transanal hybrid colon resection seems a feasible and safe hybrid NOTES procedure that can be usefully introduced into clinical practice.

Evaluation of bacterial contamination after "pure" (totally) transvaginal NOTES diagnostic peritoneoscopy with biopsies in swine: a comparative study with laparoscopy

INTRODUCTION

Bacterial contamination from viscerotomy is a barrier to natural orifice translumenal endoscopic surgery (NOTES). The aim of this survival study is to evaluate pure (totally) transvaginal NOTES bacterial contamination compared with laparoscopy in pigs.

METHODS

Twelve adult female pigs underwent peritoneoscopy with liver and peritoneal biopsies, using either laparoscopy (Glap, six animals) or pure transvaginal (GNOTES) access, and were maintained alive for 7 days. In all animals, blood cultures were taken at baseline, and after 24 h and 7 days postoperatively. Swab cultures from vagina (GNOTES) and skin (Glap) were obtained pre- and post-antisepsis. Peritoneal fluid culture was obtained at necropsy. For statistical analysis, Glap and GNOTES were compared for presence of positive bacterial cultures (qualitative bacterial analysis) using Fisher's test, with level of significance set at p < 0.05.

RESULTS

All animals had good postoperative outcome. One animal had transient perioperative bleeding from a transvaginal access. Two animals in Glap and one in GNOTES had positive blood cultures after the procedure. All animals from GNOTES and Glap presented with mixed flora pre-antisepsis. After antisepsis, one animal (GNOTES) presented with a positive vaginal swab culture (a single bacterial strain was identified). There was no positive skin swab culture in Glap. There were no signs of intra-abdominal infection at necropsy. In two animals, one from Glap and another from GNOTES, intra-abdominal culture was positive for Corynebacterium spp. and Escherichia coli, respectively. There was no correlation between the bacterial flora found at the access site and in the peritoneal cultures.

CONCLUSIONS

Pure transvaginal peritoneoscopy with liver and peritoneal biopsy in swine is feasible and associated with bacterial contamination comparable to laparoscopy. Peritoneal bacterial contamination was clinically insignificant after 1 week postoperatively. Preoperative antisepsis provided significant reduction of bacterial load prior to transvaginal and laparoscopic procedures.

Transvaginal single-port natural orifice transluminal endoscopic surgery for benign uterine adnexal pathologies

Transvaginal natural orifice transluminal endoscopic surgery (NOTES) with pneumoperitoneum has been used in cholecystectomies, appendectomies, and nephrectomies, but transvaginal NOTES using a single port in gynecologic procedures has not been described despite gynecologist familiarity with the vaginal approach. We performed transvaginal single-port NOTES in 10 women with benign uterine adnexal disease: oophorectomy in 3 patients, salpingostomy and salpingectomy in 2 each, and ovarian cystectomy, paratubal cystectomy, and ovarian wedge resection in 1 each. The patients were discharged at 1 or 2 days postoperatively, and were satisfied, with minimal pain, no abdominal scar, and no complications at 2-month follow-up. We conclude that transvaginal single-port NOTES to treat benign uterine adnexal disease is a feasible and attractive option.

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.

Safe sigmoid access for natural orifice transluminal endoscopic surgery (NOTES)

One of the main challenges in transluminal surgery is sterile and safe access. For many interventions, a transanal approach would be ideal but it is considered too risky because of contamination and the danger of secondary leakage. A new safe and sterile transanal access was developed, combining four basic principles: (i) the creation of a decontaminating hydroperitoneum, (ii) the use of an overtube, (iii) defining the entry point with ultrasound and (iv) dedicated closure technique. Applicability and reliability was first proven in extensive animal experiments. Feasibility of the concept in humans was subsequently demonstrated in cadavers.

Natural orifice transluminal endoscopic surgery: New minimally invasive surgery come of age

Although in the past two decades, laparoscopic surgery, considered as a great revolution in the minimally invasive surgery field, has undergone major development worldwide, another dramatic surgical revolution has quietly appeared in recent years. Ever since Kalloo’s first report on transgastric peritoneoscopy in a porcine model in 2004, interest in a new surgical procedure named natural orifice transluminal endoscopic surgery (NOTES) has blossomed worldwide. Considering that a NOTES procedure could theoretically avoid any abdominal incision, operation-related pain and scarring, many surgeons and endoscopists have been enthusiastic in their study of this new technique. In recent years, several NOTES studies have been carried out on porcine models and even on humans, including transvaginal cholecystectomy, transgastric appendectomy, transvaginal appendectomy, and transvesical peritoneoscopy. So what is the current situation of NOTES and how many challenges do we still face? This review discusses the current research progress in NOTES.

Original technique to close the transrectal viscerotomy access in a NOTES transrectal and transgastric segmental colectomy

Segmental colectomy is an ideal procedure for natural orifice transluminal endoscopic surgery (NOTES). Transanal endoscopic approaches have enabled rectosigmoid colectomy through a viscerotomy that is resected with the specimen. To extend NOTES segmental colectomy to the entire colon and beyond, a rectal viscerotomy will have to be safely and effectively closed at the end of the procedure. A new technique for rectal viscerotomy closure using a circular EEA hemorrhoid and prolapse stapler with DST series technology (Covidien) is described.

Disinfection of the Access Orifice in NOTES: Evaluation of the Evidence Base

Introduction. Appropriate prevention of infection is a key area of research in natural orifice translumenal endoscopic surgery (NOTES), as identified by the Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR). Methods. A review of the literature was conducted evaluating the evidence base for access orifice preparation/treatment in NOTES procedures in the context of infectious complications. Recommendations based on the Oxford Centre for Evidence-Based Medicine guidelines were made. Results. The most robust evidence includes several experimental randomised controlled trials assessing infectious complications in the transgastric approach to NOTES. Transvaginal procedures are long established for accessing the peritoneal cavity following disinfection with antiseptic. Only experimental case series for transcolonic and transvesical approaches are described. Conclusion. Grade C recommendation requiring no preoperative preparation can be made for the transgastric approach. Antiseptic irrigation is recommended for transvaginal (grade C) NOTES access, as is current practice. Further human trials need to be conducted to corroborate the current evidence base for transgastric closure. It is important that future trials are conducted in a methodologically robust fashion, with emphasis on clinical outcomes and standardisation of enterotomy closure and postoperative therapy.

Perirectal NOTES access: "down-to-up" total mesorectal excision for rectal cancer

OBJECTIVES

Clinical natural orifice surgery has been applied for abdominal surgery in recent years, mostly by vaginal and oral access. The study describes preliminary successful human applications of transcolonic natural orifice transluminal endoscopic surgery (NOTES), using a new transrectal total mesorectal excision procedure for rectal cancer.

METHODS

Institutional review board approval was obtained for the study. In 2 patients with rectal adenocarcinoma, total mesorectal resection and rectosigmoidectomy with lymphadenectomy was performed using a low NOTES transcolonic access. "Down-to-up" mesorectal dissection was achieved either using a flexible scope or a transrectal single port device. The specimens were extracted transanally, and transorificial low anastomosis was performed.

RESULTS

Operative time was 350 and 360 minutes, respectively; no complications occurred and patients were discharged after 6 days.

CONCLUSION

Successful human reports on transcolonic NOTES suggest potential applications. The treatment of colorectal diseases through transorificial single port or flexible perirectal NOTES access are promising new approaches besides current methods to improve patient care.

Development of a feasible transrectal natural orifice transluminal endoscopic surgery (NOTES®) approach in a cadaveric appendectomy model: anterior is better

BACKGROUND

The transrectal natural orifice transluminal endoscopic surgery (NOTES) approach is a potentially promising alternative to transgastric or transvaginal approaches for intraperitoneal procedures. However, whether the optimal transrectal approach for intraperitoneal surgery is anterior or posterior remains unknown. To evaluate this, a prospective comparison of anterior and posterior transrectal NOTES approaches in a cadaveric appendectomy model was performed.

METHODS

Operations were performed on human cadavers using a transanal endoscopic microsurgery (TEM) scope to assist with access and closure. Posterior access was achieved by tunneling cephalad through the retrorectal space into the peritoneal cavity. Anterior transrectal access was established through the rectal wall just above the peritoneal reflection. A dual-channel flexible endoscope was used to perform appendectomies. Rectotomies were closed using sutures or staples. Operative time, degree of laparoscopic assistance, complications, and leak-testing results were recorded.

RESULTS

This study investigated 10 cadavers with access and closure attempted using both anterior (n = 10) and posterior (n = 5) approaches, whereas appendectomies were performed using either an anterior (n = 8) or a posterior (n = 2) approach. The anterior approach required less time than the posterior approach for peritoneal access (4 ± 1 vs. 61 ± 14 min; p < 0.001), specimen extraction (2 ± 1 vs. 5 ± 1 min; p < 0.01), and the total operation (99 ± 35 vs. 176 ± 26 min; p = 0.02). A "pure" NOTES dissection was possible with the anterior approach using rigid transanal instruments for assistance. Dissection time, closure time, and the incidence of complications were similar between the two approaches. Leak testing of closures showed significant variability for all closure types.

CONCLUSION

Transrectal NOTES appendectomy is feasible in a cadaveric model using an anterior transrectal approach. This approach is technically easier, results in shorter operative times, and allows for a "pure" NOTES dissection compared with a posterior transrectal approach. Leak pressure testing of NOTES closures is unreliable in the cadaveric model.

Transrectal hybrid natural orifice transluminal endoscopic surgery (NOTES) nephrectomy in a porcine model

OBJECTIVE

To examine feasibility of transrectal hybrid natural orifice translumenal endoscopic surgery (NOTES) nephrectomy in the porcine model. NOTES uses ports of entry to the peritoneal cavity instead of abdominal wall incisions, thereby eliminating visible scar and also potentially reducing postoperative pain.

METHODS

After obtaining Institutional Animal Care and Use Committee approval, 3 female pigs (45 kg) underwent transrectal hybrid NOTES nephrectomy (2 right, 1 left). Pneumoperitoneum was created by a periumbilically-inserted 12-mm trocar, through which a laparoscope was advanced to obtain intraabdominal visualization. A 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 window in the peritoneum 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 extraction bag was deployed transrectally and the specimen was delivered intact, followed by transrectal incision closure.

RESULTS

Transrectal hybrid NOTES nephrectomy was successfully performed in all cases. Mean operative time was 180 minutes (30 minutes for rectal access). Estimated blood loss was 50 mL. On necropsy, no intraabdominal injuries were noted.

CONCLUSIONS

In this initial report on feasibility of transrectal hybrid NOTES nephrectomy, we were able to perform the procedures with minimal blood loss and extract intact specimen. Survival studies are prerequisite to assess sterility and short- and long-term complications. This approach may be useful as an alternative to transvaginal access.

Transgastric or trans-sigmoidal? The impact of the choice of access on task performance in target natural orifice translumenal endoscopic surgery procedures

INTRODUCTION

The effect of the choice of access upon endoscope control during a navigational task is explored within a simulator model.

MATERIALS AND METHODS

The study was conducted within the endoscopic-laparoscopic interdisciplinary training entity (ELITE) model (Minimally Invasive Therapy and Intervention Research Group [MITI], Technische Universität, Germany)--a validated natural orifice translumenal endoscopic surgery (NOTES) simulator. Seventeen subjects, 15 with no endoscopic experience, navigated the endoscope from predefined trans-sigmoidal and transgastric access points to the appendix and the gallbladder. A previously defined and validated quantitative analysis of endoscope control, in addition to time taken to complete the task, was used to evaluate overall performance. The quantitative analysis extrapolated the movements of the subject's wrist in control of the endoscope and rated the movements using a scoring system of 0-3 based upon the smoothness of the movements recorded.

RESULTS

Although no significant difference in terms of performance time was demonstrated between the two approaches to the appendix (36.6 ± 14.7 seconds TG and 29.8 ± 16 seconds TS) (P = .214), when the endoscope control score was compared, a significant difference was confirmed (3 TG and 7 TS) (P < .001). With regard to the approach to the gallbladder, a significant difference in terms of both the performance time (19.8 seconds TG and 35.6 seconds TS) (P < .001) and the quality of endoscope control (7 TG and 5 TS) (P = .001) was demonstrated.

CONCLUSION

The choice of access route impacts directly on the ease with which the endoscopist navigates to the target. Within this study, the trans-sigmoidal appears the most appropriate to access the appendix and the transgastric for the gallbladder.

Transgastric small bowel resection and anastomosis: a survival study

BACKGROUND

Recently, natural orifice transluminal endoscopic surgery has emerged with new ideas of a transgastric access. The authors have evaluated the possibility of transgastric bowel resection with several modifications. This study aimed to evaluate transgastic small bowel resection using an automated stapling device via an assisting trocar. In a survival experiment, the possible technical problems, medical complications, and safety of the procedure were investigated as well as the postoperative course and follow-up care.

METHODS

The study protocol was submitted to the animal research committee and approved. A total of 13 swine with a body weight of 25 kg (range, 20-46 kg) were investigated and entered into the study. General anesthesia was induced by certified personnel using ketamine, halothan, oxygen, and nitrous oxide. One trocar was used for laparoscopic assistance. A needleknife was used to complete a 1.5-cm-long gastrotomy. The gastroscope was advanced into the peritoneal cavity, and a small bowel loop was identified. Through the second channel of the scope, a coag-grasper was used to dissect the mesentery. A linear stapler was inserted through the assisting trocar, and the resection was performed. Afterward, the bowel ends were reopened, and the stapler was reinserted for a side-to-side anastomosis. The specimen was removed via the stomach. Gastric closure was completed using laparoscopic mini-instruments. All problems were prospectively documented. Follow-up evaluation was performed over 2 weeks. The animals were killed and reopened, and evidence of adhesions, infection, and abscess formation was evaluated.

RESULTS

In this study, 13 female animals with a body weight of 25 kg (range, 20-46 kg) underwent surgery. No mortality or postoperative complications occurred. The animals had stable weight development. After a follow-up period of 2 weeks, the animals were killed. The findings included minor adhesions, no abscess, and no inflammation.

CONCLUSION

Transgastric bowel resection with minor laparoscopic assistance is a safe experimental procedure when performed by surgeons with adequate and extensive training. These experimental procedures should be evaluated carefully and critically in clinical practice.

Cardiopulmonary and immunologic effects of transvaginal natural-orifice transluminal endoscopic surgery cholecystectomy compared with laparoscopic cholecystectomy in a porcine survival model

BACKGROUND

A few studies have addressed the physiology related to a basic natural-orifice transluminal endoscopy surgery (NOTES) procedure, such as transgastric peritoneoscopy, but the physiologic impact of more complex NOTES procedures has not been previously examined.

OBJECTIVE

To evaluate the cardiopulmonary and immunologic effects of transvaginal NOTES cholecystectomy compared with laparoscopic cholecystectomy.

SETTING

Survival experiments in 10 40-kg female pigs assigned to transvaginal cholecystectomy and laparoscopic cholecystectomy groups.

INTERVENTIONS

Transvaginal cholecystectomy was performed with the assistance of a needlescopic device, and laparoscopic cholecystectomy was performed in the standard manner.

MAIN OUTCOME MEASUREMENTS

Cardiopulmonary and immunologic parameters in the transvaginal cholecystectomy group were compared with those in the laparoscopic cholecystectomy group. Cardiopulmonary parameters included heart rate, blood pressure, saturation pulse oximetry, intratracheal pressure, and arterial blood gases. Immunologic parameters included white blood cell count, tumor necrosis factor-α, interleukin-1β, and interleukin-6.

RESULTS

All procedures were performed successfully without complications. Although operation times were longer for transvaginal cholecystectomy than for laparoscopic surgery, cardiopulmonary changes were similar and stable in both groups. White blood cell count, interleukin-1β, and interleukin-6 did not differ between the 2 groups, and the increase in tumor necrosis factor α after transvaginal cholecystectomy was significantly smaller on postoperative day 1 than after laparoscopic cholecystectomy (133.4 pg/mL vs 200.4 pg/mL; P < .05).

LIMITATIONS

Animal model and small sample size.

CONCLUSIONS

Transvaginal cholecystectomy resulted in cardiopulmonary stability and well preserved immune function similar to those of laparoscopic cholecystectomy, suggesting that NOTES may be less invasive than laparoscopic surgery.

Randomized, blinded comparison of transgastric, transcolonic, and laparoscopic peritoneoscopy for the detection of peritoneal metastases in a human cadaver model

BACKGROUND

Natural orifice transluminal endoscopic surgery peritoneoscopy may be able to replace laparoscopic peritoneoscopy (LAP) for staging of GI malignancies if it is proven to be equally accurate and safe.

OBJECTIVE

To compare transgastric peritoneoscopy (TGP) and transcolonic peritoneoscopy (TCP) to LAP, pairwise, in a randomized, blinded (to location and number of beads) human cadaver model with simulated peritoneal metastases.

DESIGN

Metastases were simulated by 2.5-mm, color-coded beads, which were placed into the peritoneal cavity via an open approach. In previous porcine experiments, LAP resulted in a yield of 95%. By using a noninferiority design with a margin of equivalence of 15%, we needed a sample size of 34 beads for 80% power. Randomization was performed for number and location of beads. Eighteen experiments were performed on 6 fresh-frozen human cadavers.

SETTING

Experimental surgical laboratory.

INTERVENTION

LAP, TGP, and TCP were performed in randomized order by one of two surgeons/endoscopists blinded for location and number of beads.

MAIN OUTCOME MEASUREMENTS

Number of beads detected and touched.

RESULTS

LAP found and touched 33 beads (yield 97%), TGP 26 beads (76%; difference in yield vs LAP was -20.5 [95% CI, -26.3 to -9.27]), and TCP 29 beads (85%; difference in yield vs LAP was -11.8 [95% CI, -14.6 to 4.98]). Beads that were missed were mostly located at the inferior liver surface: TGP missed 6 of 9 of these beads (67%), TCP 4 of 9 (44%).

LIMITATIONS

Cadaver model.

CONCLUSION

In this prospective, blinded, comparative trial in a human cadaver model, TCP was comparable to LAP in detecting simulated metastases. TGP was inferior to LAP. Future development should focus on improved visualization of the inferior surface of the liver.

Current developments in natural orifices transluminal endoscopic surgery: An evidence-based review

Tremendous advances have been made in recent years addressing the key obstacles to safe performance and introduction of human natural orifice transluminal endoscopic surgery (NOTES). Animal studies have focused on identifying optimal solutions to these obstacles, in particular methods of creating transluminal access, safe closure of the point of access, and development of a multitasking platform with dedicated instruments. Whether the performance data generated from these animal studies can be reproduced in humans has yet to be determined. Reports of human NOTES procedures are emerging, and the possibility of accomplishing human NOTES based on existing technology has been demonstrated. However, dedicated platforms and devices are still lacking to allow for pure NOTES procedures, and whether NOTES can deliver the postulated benefits of earlier recovery and improved cosmesis remains uncertain.

Hydroperitoneum-facilitated EUS-guided peritoneal entry and closure of alternate access sites for NOTES

BACKGROUND

Access sites other than the anterior gastric wall may provide improved ergonomics for natural orifice transluminal endoscopic surgery (NOTES). Endoscopic ultrasound (EUS) guidance significantly reduces, but does not eliminate, risk of access through these alternate sites. This study evaluates the utility of hydroperitoneum as an adjunct to EUS-guided access and closure of alternate access sites for NOTES.

METHODS

Access and closure procedures were initially performed with EUS guidance alone, and subsequently, because of complications resulting from this technique, the procedures were performed with the aid of a transabdominal hydroperitoneum.

RESULTS

In this nonrandomized study, 6 access and closure procedures performed with EUS guidance alone resulted in 4 complications. After modifying the technique to incorporate pre-access hydroperitoneum, 7 EUS-guided access and closure procedures were performed without significant complications.

CONCLUSIONS

Hydroperitoneum appears to be an effective adjunct to ensure the safety of EUS-guided peritoneal entry and closure of alternate access sites for NOTES.

Getting ready for surgery through natural orifice

The technical background of pure Natural Orifice Translumenal Endoscopic Surgery (NOTES) surgery has not been created yet, but ever more reports are being published on hybrid NOTES surgery and single-port surgical interventions, which have appeared as a result of device development inspired by NOTES. Surgery carried out through single ports only differ from pure NOTES in respect of the access orifice, which makes learning this technique extremely important for anyone whishing to implement a surgical intervention through a natural orifice. Numerous publications have appeared by now on the single port or hybrid NOTES surgery of various organs (gall bladder, kidney, large bowel). Based on these, most surgery is safely feasible through one port as well, but the surgery takes longer and it is not significantly less painful than a “traditional” laparoscopic intervention. Long-term results are still missing, primarily in what concerns the frequency of infections and post-operative hernia. We have received an answer to part of the dilemmas formulated in the White Paper. Besides specially bent laparoscopic devices robot technology and devices controlled by extracorporal magnets may both be a solution to the problem of triangulation. The transvaginal and transgastric paths do not seem to cause significant risks from the viewpoint of infections, but the closing of viscerotomy in the case of the stomach is far from being solved. In respect of learning and practicing new surgical techniques no method exists at the moment that could be considered the “gold standard”. Besides the earlier questions there are new ones as well awaiting partial solutions (e.g. necessity of drain following a NOTES surgery, oncologic principles).

Transgastric small bowel resection by using hybrid technique — Experimental study

Introduction:The Natural Orifice Transluminal Endoscopic Surgery (NOTES) is an abdominal operation carried out with flexible endoscopic instruments and their advanced versions via natural orifices. The NOTES causes theoretically less pain, operative stress, shorter hospitalization, quicker recovery and it is scarless. The aim of this investigation was to evaluate the feasibility and safety of transgastric small bowel resection. Materials and methods: Seven domestic pigs were investigated and entered the study; body weight 25 kg in average. General anesthesia was performed. One trocar was used for laparoscopic observations during gastrotomy and transgastric penetration with the gastroscope, later for assistance with a grasper for manipulation of the bowel loops and for the application of the linear stapling device. Then the needle knife was used to complete a 1.5 cm long incision in the gastric wall. The gastroscope was advanced into the peritoneal cavity and a small bowel loop was identified and elevated with a flexible grasper. Through the second channel of the scope a coag grasper was used to dissect the mesentery. Then a linear stapler was inserted through the assisting trocar and the resection was performed. Afterwards the bowel ends were opened with the needle knife and the stapler was reinserted for a side-to-side anastomosis. The specimen was removed via the stomach. Gastric closure was completed by laparoscopic mini-instruments through the stapler-port. All special events and all problems were prospectively documented. Follow-up was performed over 2 weeks and body weight was recorded. Then a laparoscopy was performed to document adhesions or abscess formation. Finally the animals were sacrificed to evaluate further evidence of infection or adhesions. Results: The operations were carried without complications, there was no case of letal outcome. On the 12th day the abdominal laparoscopic revision was carried out, after the revision in one case adhesion could be detected, no other kinds of complications were noticed. Conclusion: According to our results, the transgastric small bowel resection is a safe procedure, but further special instruments are needed. These experimental procedures should be evaluated carefully and critically in clinical practice.

[Transsigmoid access for NOTES]

Transsigmoidal access for NOTES operations is not limited by gender and offers an outstanding controllability of the entry point. Practically all anatomical regions of the abdomen are easily accessible. However, it is particularly prone to contamination and leakage and insufficiency of the access mean that it is far more prone to complications than using alternative access points. Currently, only few data are available on the results of animal experiments and differing technical approaches have been employed. Dedicated surgical instruments are required which should be modified according to the well proven transanal endoscopic microsurgery (TEM) set of instruments. In addition, specialized instrumentation (overtubes/trocars) and the use of transanal ultrasound seem to be recommendable.

[Orientation of endoscopic images: rectification by gravity]

A known problem in endoscopic surgery (especially with flexible video endoscopes) is the absence of a stable horizon in endoscopic images displayed on a monitor. With our "ENDOrientation" approach, image rectification, even in non-rigid endoscopic surgery (particularly NOTES), can be realized with a tiny MEMS tri-axial inertial sensor placed on the tip of an endoscope. This sensor measures the impact of gravity on each of the three orthogonal accelerometer axes in real time. After an initial calibration and temporal filtering of these three data steams, the rotation angle of an endoscope can be estimated directly. The achievable sampling rate of the inertial sensor is above the usual endoscopic video frame rate of 25 Hz; the rotation accuracy is approximately one degree. The image rectification can be performed in real time by digitally rotating the endoscopic video signal. Improvements and benefits have been evaluated in animal studies: coordination and movement of different instruments was rated to be much more intuitive with a stable horizon on endoscopic images. The recorded time stamps and position tracks clearly support this observation.

Current experience and future directions of completely NOTES colorectal resection

Clinical implementation and widespread application of natural orifice translumenal surgery (NOTES) has been limited by the lack of specialized endoscopic equipment, which has prevented the ability to perform complex procedures including colorectal resections. Relative to other types of translumenal access, transanal NOTES using transanal endoscopic microsurgery (TEM) provides a stable platform for endolumenal and direct translumenal access to the peritoneal cavity, and specifically to the colon and rectum. Completely NOTES transanal rectosigmoid resection using TEM, with or without transgastric endoscopic assistance, was demonstrated to be feasible and safe in a swine survival model. The same technique was successfully replicated in human cadavers using commercially available TEM, with endoscopic and laparoscopic instrumentation. This approach also permitted complete rectal mobilization with total mesorectal excision to be performed completely transanally. As in the swine model, transgastric and/or transanal endoscopic assistance extended the length of proximal colon mobilized and overcame some of the difficulties with TEM dissection including limited endoscopic visualization and maladapted instrumentation. This extensive laboratory experience with NOTES transanal rectosigmoid resection served as the basis for the first human NOTES transanal rectal cancer excision using TEM and laparoscopic assistance. Based on this early clinical experience, NOTES transanal approach using TEM holds significant promise as a safe and substantially less morbid alternative to conventional colorectal resection in the management of benign and malignant colorectal diseases. Careful patient selection and substantial improvement in NOTES instrumentation are critical to optimize this approach prior to widespread clinical application, and may ultimately permit completely NOTES transanal colorectal resection.

Needle-based confocal endomicroscopy for in vivo histology of intra-abdominal organs: first results in a porcine model (with videos)

BACKGROUND

Probe-based confocal laser scanning endomicroscopy enables in vivo real time histopathology of the mucosa layer. Recently, a prototype of a new confocal miniprobe has been developed that is small enough to be introduced through a 22-gauge puncture needle.

OBJECTIVE

The aim of this study was to evaluate the feasibility of such needle-based confocal laser scanning endomicroscopy (nCLE) for in vivo histology of various organs in a porcine model.

DESIGN

Feasibility study.

SETTING

Nonsurvival animal experiments with the animals under general anesthesia at three academic centers.

INTERVENTIONS

Ten pigs were examined while they were under general anesthesia. Either EUS-guided organ puncture or natural-orifice transluminal endoscopic surgery (NOTES) procedure was used. The confocal miniprobe was inserted through the 22-gauge needle, and puncture of various intra-abdominal structures and organs was performed (lymph nodes, diaphragm, ovaries, liver, spleen, and pancreas) after intravenous injection of fluorescein (5-10 mL 1% or 2 mL 10% solution). Real-time sequences were recorded. Biopsy specimens were taken for standard histopathology.

MAIN OUTCOME MEASUREMENTS AND RESULTS

It was technically feasible to introduce the needle-based confocal miniprobe into various organs at the time of EUS or NOTES procedures. The device enabled real-time in vivo collection of images at histologic resolutions and of acceptable image quality from several intra-abdominal organs interrogated.

LIMITATIONS

Data were assessed in an experimental animal setting and on healthy organs only.

CONCLUSIONS

Needle-based confocal laser endomicroscopy (CLE) of intra-abdominal organs is feasible in a porcine model. This innovative, minimally invasive technique has the potential to facilitate in vivo histology during EUS punctures or NOTES peritoneoscopy.

Usefulness of a flexible port for natural orifice transluminal endoscopic surgery by the transrectal and transvaginal routes

We developed a flexible port for NOTES which allows the use of conventional forceps for laparoscope-assisted surgery without change. The port is not affected by the location of the through hole in the gastrointestinal tract or vagina which elicits a problem in conventional NOTES, and its length can be adjusted during surgery by cutting the port itself. The port is made of polymer resin with a low friction coefficient. Furthermore, the port walls have a square wave structure which contributes to (1) the prevention of devices, for example, endoscope, from getting stuck at the time of insertion and retrieval, (2) the prevention of port slippage in the surgical opening for port insertion, (3) the prevention of unexpected port removal, (4) the prevention of port bore deformation, and (5) the improvement of port flexibility in the longitudinal direction. We validated the insertion and retrieval capacities of commercially available forceps for laparoscope-assisted surgery and power devices. Furthermore, we used the flexible port to conduct cholecystectomy and partial gastrectomy. We could confirm that the selection of the flexible port diameter according to the device type allowed the smooth insertion and retrieval of the device and that the port produced no air leakage. We affirmed that it is possible to conduct surgery by the cross or parallel method similarly to single port surgery. We considered that the flexible port has a potential of becoming a revolutionary port in NOTES.

Cirurgia por orifícios naturais transcolônica: acesso NOTES peri-retal (PNA) para excisão mesoretal total

OBJETIVOS: Cirurgia por orifícios naturais tem sido recentemente aplicada em series clínicas para cirurgia abdominal. Apesar de potenciais vantagens do acesso NOTES transcolônico para doenças colorretais, este ainda não havia sido utilizado clinicamente. O presente trabalho descreve a primeira aplicação bem-sucedida de NOTES transcolônico da literatura, em uma nova abordagem de excisão mesoretal total (TME) para cancer de reto. MÉTODOS: Foi obtida aprovação de Comitê de Ética em Pesquisa para cirurgias por orifícios naturais, e o paciente assinou termo de consentimento informado. Em um paciente de 54 anos portador de adenocarcinoma de reto, o procedimento de retossigmoidectomia e linfadenectomia, com excisão mesoretal total foi realizada utilizando um acesso posterior transcolônico pouco acima da borda anal. A dissecção mesorretal foi conseguida utilizando um colonoscópio flexível e instrumentos endoscópicos, com assistência laparoscópica. O espécime foi retirado via transanal, e anastomose foi transorificial, com estoma proximal de proteção. RESULTADOS: O tempo operatório foi de 350 min, não ocorrendo complicações operatórias. A evolução pós-operatória foi favorável, e o paciente recebeu alta no sexto dia de pós-operatório com dieta plena. CONCLUSÃO: Este primeiro relato bem sucedido de cirurgia NOTES transcolônica traz potencialmente novas fronteiras de aplicações clínicas na cirurgia minimamente invasiva. O tratamento de doenças colorretais utilizando o novo acesso flexível PNA (Perirectal NOTES Access) é uma promissora nova abordagem, paralelamente à laparoscopia e cirurgia aberta, para melhoria do tratamento dos pacientes.