Endoscopic sutured closure of a gastric natural orifice transluminal endoscopic surgery access gastrotomy compared with open surgical closure in a porcine model. A randomized, multicenter controlled trial

Endoscopic ultrasound-guided puncture suture device versus metal clip for gastric defect closure after endoscopic full-thickness resection: A randomized, comparative, porcine study

Objective:

The secure closure of the wall defect is a critical stage of endoscopic full-thickness resection (EFTR). The aim of this study was to compare the closure of post-EFTR defects using an endoscopic ultrasound-guided puncture suture device (PSD) with the metal clip (MC) technique in a randomized, comparative, porcine study.

Methods:

We performed a randomized comparative survival study that included 18 pigs. The circular EFTR defects with a diameter of approximately 20 mm were closed with either a PSD or MC. Serum levels of interleukin-6 (IL-6) were determined preoperatively and on a postoperative day (POD) 1, 3, and 7. Three animals from each group were sacrificed at the end of the 7^th, 14^th, and 30^th POD. Tissue samples retrieved from the closure sites were examined macroscopically and microscopically.

Results:

Resection and closure were performed in 18 pigs (100%) without major perioperative complications. The mean closure time was significantly longer in the MC group than in the PSD group (25.00 ± 3.16 min vs. 1.56 ± 0.39 min; P < 0.05). Preoperative and POD 7 serum levels of IL-6 did not differ between the two groups. However, on POD 1, the IL-6 levels were observed to be significantly greater in the MC group than in the PSD group (P < 0.005). No significant differences between the PSD and MC groups were observed at necropsy.

Conclusion:

In this in vivo porcine model, PSD is a feasible device that achieves post-EFTR defect closure with a much shorter closure time and with less immunological responses than the MC technique.

Endoscopic ultrasound-guided inoculation of transmissible venereal tumor in the colon: A large animal model for colon neoplasia

Background:

To develop and evaluate the feasibility of emerging interventions, animal models with accurate anatomical environment are required.

Objectives:

We aimed to establish a clinically relevant colorectal tumor model with canine transmissible venereal tumor (CTVT) utilizing endoscopic ultrasound (EUS) imaging guidance.

Design:

Survival study using a canine model.

Setting:

Endoscopic animal research laboratory at a tertiary cancer center.

Materials and Methods:

This study involved five canines.

Interventions:

A colorectal tumor model was established and evaluated in five canines under cyclosporine immune suppression. Under endoscopic imaging guidance, saline was injected into the submucosal layer forming a bleb. Subsequently, CTVT was inoculated into the bleb under EUS guidance. Endoscopy was the primary method of assessing tumor growth. Tumors developed in 60-130 days. Upon detection of lesions >1 cm, the animals were euthanized and the tumors were harvested for histopathological characterization.

Main outcome measurements:

Success rate of tumor growth. The presence or absence of vasculature inside tumors.

Results:

Colorectal tumor successfully developed in three out of the five animals (60%). Among the ones with tumor growth, average inoculated CTVT volume, incubation time, and tumor size was 1.8 cc, 65.7 days, and 2.0 cm, respectively. The two animals without tumor growth were observed for >100 days. In all the tumors, vascular structure was characterized with CD31 imunohistochemical stain.

Limitations:

Small number of animals.

Conclusion:

We succeeded in creating a new colorectal tumor canine model with CTVT utilizing EUS.

Endoscopic clip closure of gastrointestinal perforations, fistulae, and leaks

Development of endoscopic devices to close perforations has certainly revolutionized endoscopy. Immediate closure of perforations eliminates the need for surgery, which allows us to push the limits of endoscopic surgery from the mucosal plane to deep submucosal layers and eventually transmurally. The present article focuses on endoscopic closure devices, closure techniques, followed by a review of animal and clinical studies on endoscopic closure of perforations.

Evaluation of feasibility, efficiency and safety of a pure NOTES gastrojejunal bypass with gastric outlet obstruction, in an in vivo porcine model

INTRODUCTION

Natural orifice transluminal endoscopic surgery (NOTES) gastrojejunal anastomosis (GJA) is a less invasive surgery for bariatric procedures and gastric outlet obstruction. The aim of this study was to evaluate the feasibility, efficacy, and safety of a pure NOTES gastrojejunal bypass using an in vivo porcine model.

MATERIAL AND METHODS

A prospective study was performed on nine swine. A double-channel scope was used. The intervention steps were: (i) gastric incision; (ii) peritoneal access; (iii) jejunal loop selection and mobilization into the stomach; (iv) stoma creation within the gastric wall and incision; (v) anastomosis suture and pylorus closure using a T-tag prototype. The animals were assessed clinically for 3 weeks including the weight gain. The patency of the GJA was assessed at necropsy and a histological analysis was performed.

RESULTS

We successfully performed all the procedures with a mean (standard deviation [SD]) operative time of 108 (26) minutes. We used a mean of 5.55 (1.30) stitches. There were no intraprocedural adverse events. Five animals survived up till euthanasia at 3 weeks (65 %). These showed a significant difference in weight curves of a loss of 3.2 kg compared with gain of 5.2 kg in a control group. Four pigs died from anastomotic dehiscence complicated by peritonitis.

CONCLUSION

Gastrojejunal bypass with a pure NOTES approach is feasible. This procedure is effective, resulting in a patent anastomosis and a significant weight loss. However, the anastomotic dehiscence is a major concern because of its mortality rate, and further studies including improvement of the suturing device and the technique are needed.

Gastrojejunal Anastomosis Exclusively Using the "NOTES" Technique in Live Pigs: A Feasibility and Reliability Study

INTRODUCTION

Natural orifice transluminal endoscopic surgery (NOTES) could reduce procedure-associated morbidity and mortality. The aim of this study was to determine the feasibility of performing a simple model of gastrojejunal anastomosis in a living porcine model exclusively using NOTES.

METHODS

It was a prospective experimental animal study concerning pigs weighing between 25 and 30 kg. Endoscopies were performed using a double-channel gastroscope. A preliminary phase allowed for the development of the technique on 3 animals that were immediately euthanized. The experimental phase included the implementation of a gastrojejunal anastomosis in 9 animals. Antibiotic therapy was continued for 7 days with gradual feeding. Surviving animals were euthanized after 3 weeks. Anastomosis permeability in each animal was confirmed by opacification, endoscopy, and histopathological analysis. The main outcome measurements were the feasibility and animal survival at 3 weeks postsurgery.

RESULTS

The entire procedure was performed on 9 animals (4 males and 5 females). Anastomosis required 4.7 ± 1.2 stitches (range 4-7). The average total length of the procedure was 143 ± 50.8 minutes (range 87-225 minutes). One bleeding, 2 suture dehiscences, and a poor stomach incision were the immediate complications endoscopically resolved. At 3 weeks, 5 animals had survived. Three animals died as a result of anastomotic leakage confirmed at necropsy and histopathology. In the surviving animals, histology confirmed permeable anastomoses with collagen scar tissue and continuity of the mucosa and mucosa muscle layers.

CONCLUSION

Successful gastrojejunal anastomosis by NOTES is technically feasible but is subject to a learning curve.

Omentum patch substitute for facilitating endoscopic repair of GI perforations: an early laparoscopic pilot study with a foam matrix plug (with video)

BACKGROUND

Endoscopic perforations are surgically repaired by using an omentum patch. Omentum substitutes may have broader applications particularly in certain sites (eg, esophagus).

OBJECTIVE

Evaluate a self-expandable foam matrix plug as a synthetic omentum substitute for repairing iatrogenic gastric perforations in a 4-week survival pig model.

DESIGN

Experimental pilot study.

SETTING

Laboratory.

INTERVENTION

A laparoscopic plug repair of a 1-cm, full-thickness, gastric perforation was carried out by using either a polyurethane foam matrix plug (FMP, 8 animals) or an omentum plug (OP, 6 animals, control group).

MAIN OUTCOME MEASUREMENTS

Follow-up endoscopy was carried out at 1 and 4 weeks. At necropsy, the perforation site was evaluated for adhesions and histology by using hematoxylin and eosin analysis. A portion of the implant was sent for bacterial and fungal culture.

RESULTS

All procedures were technically simple and successful. Thirteen animals thrived well for 4 weeks. One animal from the FMP group died 3 days postoperatively from diffuse peritonitis because of a misplaced plug. All remaining FMPs were intact at 4 weeks and colonized with mixed bacteria, except one animal presenting with FMP migration after 1 week. Histologically, the FMP group had more prominent inflammation and suppuration as compared with the OP group, all limited to its adjacent tissue.

LIMITATIONS

Animal study.

CONCLUSION

The FMP offered a technically simple and feasible option for repairing iatrogenic gastric perforations. With effective sealing, the clinical outcome is similar to that of an omentum patch repair. Migration and inadequate sealing is a concern, which can lead to peritonitis and sepsis. Further development is needed to improve FMP performance.

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.

Deep sedation in natural orifice transluminal endoscopic surgery (NOTES): a comparative study with dogs

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) has been mostly performed with the animal under general and inhalational anesthesia (IA-NOTES). To date, NOTES using propofol sedation (PS-NOTES) has not been investigated. This study aimed to assess the feasibility and safety of PS-NOTES for transgastric oophorectomy with carbon dioxide insufflation and to compare its success rates with those of conventional IA-NOTES.

METHODS

In this prospective randomized study, NOTES oophorectomy was performed for 19 female dogs randomized to two conditions: PS (study group) and IA (control group). Sedation success rates (ability to visualize and resect ovaries without converting to IA), operative success rates (ability to resect and retrieve both ovaries in full using only NOTES), and vital parameters including hemodynamic and respiratory changes were documented.

RESULTS

In the PS-NOTES group (n = 9), the sedation success rate was 100 %. The operative success rate was 67 % (6 of 9 animals) compared with 80 % (8 of 10 animals) in the IA-NOTES group. No purposeful movement occurred during surgical manipulation and no respiratory or cardiovascular complications in occurred the PS group. Heart rate (HR) and end-tidal carbon dioxide (ETCO(2)) were significantly higher in the PS group than in the IA group. Blood pressure (BP) was significantly higher in the PS group only during the middle part of the procedure. Only mild respiratory depression was noted in the PS group, as indicated by elevated but acceptable ETCO(2). Elevations in BP and HR are thought to be related to elevated CO(2) but did not appear to have an adverse impact on the course of the procedure. Recovery was uneventful for all the animals.

CONCLUSION

The use of PS-NOTES appears to be feasible, resulting in outcomes comparable with those for IA in dogs. Further studies are needed to determine the applicability of this concept in human NOTES.

A randomized trial comparing rates of abdominal contamination and postoperative infection among natural orifice transluminal endoscopic surgery, laparoscopic surgery, and open surgery in pigs

BACKGROUND

Bacterial contamination of the abdominal cavity and infectious complications have been debated concerning transgastric natural orifice transluminal endoscopic surgery (NOTES) procedures.

OBJECTIVE

The aim of this study was to compare bacterial contamination of the abdominal cavity and clinically relevant infections after open, laparoscopic, and transgastric NOTES procedures.

DESIGN

Randomized survival study in a porcine model.

SETTING

Animal laboratory at a university hospital.

INTERVENTION

Thirty pigs were randomized to open, laparoscopic, or transgastric NOTES uterine horn resection under sterile conditions. Bacterial cultures were obtained from the pelvic area immediately at entry of the abdominal cavity and just before closure. The left uterine horn was dissected and ligated. The animals survived for 4 weeks. At necropsy, bacterial culture was obtained from the pelvic area.

MAIN OUTCOME MEASUREMENTS

Perioperative: operation time and incision length, bacterial growth in abdominal samples. Postoperative: infections or complications, weight gain. Necropsy: signs of peritonitis or infection, abdominal bacterial growth.

RESULTS

Procedure time was significantly longer for transgastric NOTES. At the start of the procedure, 4 of the NOTES animals showed positive cultures, but only 1 showed positive cultures at the end. No open surgery or laparoscopic surgery animals showed positive cultures at these time points. At necropsy, none of the animals in the NOTES group showed bacterial growth, whereas 4 open surgery animals and 3 laparoscopic surgery animals had positive cultures. Four of these animals (2 from each group) had concurrent wound infections.

LIMITATIONS

Small sample size and lack of power calculation.

CONCLUSION

This study indicates that clinically relevant infections are rare after transgastric NOTES procedures despite evidence of bacterial contamination and longer operating times.

A new in vivo method for testing closures of gastric NOTES incisions using leak of the closure or gastric yield as endpoints

BACKGROUND

We developed a non-survival in vivo model for testing of gastric natural orifice translumenal endoscopic surgery (NOTES) closures based on the gastric yield pressure. The aim of this study was to test our model comparing different endoscopic closure techniques with surgical closure of a NOTES gastric incision.

METHODS

Laparotomy was performed in 30 pigs. One tube for air inflation and one manometry tube were inserted into the stomach via the pylorus, which was closed gas-tight, and the abdominal wall was closed. The stomach was inflated with air, and the gastroesophageal yield pressure was measured. A gastroscopy was performed, and a standard NOTES access was created followed by randomization to closure by surgical suturing, T-tags, Padlock-G over-the-scope (OTS)-clips, OVESCO OTS-clips, and traditional clips. All closures were tested twice with air insufflation. Gastric yield pressure or leak pressure of each closure was recorded.

RESULTS

The mean baseline gastric yield pressure was 80.5 mm Hg. Post-closure yield pressure was 79.9 mm Hg. Leak test results after closure were as follows: surgery, 0/6 leaked; T-tags, 1/6 leaked before reaching yield pressure (56 mm Hg); Padlock-G, 2/5 leaked (71.5 mm Hg); OVESCO OTS-clips, 3/6 leaked (27.2 mm Hg); and traditional clips, 5/6 leaked (27.2 mm Hg). TAS T-tags and surgical closures leaked significantly less than the other groups (P=.01). Traditional clips and OVESCO OTS-clips leaked at significantly lower pressures than the other three groups (P=.007).

CONCLUSION

This in vivo model using leak of the closure or the gastric yield pressure as endpoints for testing of the closure strength of a NOTES gastric access site seems to be reproducible. Our results support closure with T-tags and Padlock-G-clips over OVESCO OTS-clips and standard endoscopic clips.

New methods for innovation: the development of a toolbox for natural orifice translumenal endoscopic surgery (NOTES) procedures

BACKGROUND

Devices used for flexible intralumenal procedures are inadequate when used for intraperitoneal surgical procedures such as cholecystectomy.

OBJECTIVE

To assess/address limitations of flexible endoscopic devices in intraperitoneal surgery.

DESIGN

To describe processes used to invent new devices to facilitate this new surgical genre.

SETTING

Engineering laboratory.

PATIENTS

None. INTERVENTIONS AND INVENTIONS: Reviews of the limitations of flexible endoscopic instruments and instrumentation/invention needs for a "NOTES cholecystectomy" were completed.

MAIN OUTCOME MEASURES

The appropriateness of existing methods of device innovation was evaluated against an inventory of new technologies necessary to perform NOTES. The deficiencies in traditional innovation methods led to the creation of a novel process for invention of new medical devices: the "Inventorama."

METHODS

Cooperation between clinicians and industry to develop device concepts to enable NOTES.

RESULTS

The devices included: (1) steerable flex trocar, (2) rotary access needle, (3) bipolar hemostasis forceps, (4) Maryland dissectors, (5) articulating hook knife, (6) rotating hook knife, (7) articulating graspers, (8) scissors, (9) ligating clip applier, and (10) tissue apposition system. Six of these ten were built and tested as initial crude prototypes in the Inventorama process; two underwent major modifications. Three were invented via alternate methods, including by independent clinicians.

CONCLUSIONS

A new method for efficient medical device invention and development was created to address key technology needs for NOTES. The result was a "toolbox" of devices designed to address the key surgical activities necessary for advanced intralumenal and translumenal flexible endoscopic procedures.

Feasibility of Endoscopic Transoral Surgical Lung Biopsy in a Live Canine Model

Background. The feasibility of using a transoral approach to the thoracic cavity has not yet been measured in humans or animals. The present study aimed to evaluate the feasibility of transoral surgical lung biopsy (TOLB) in 10 canines. Methods. Through an incision over the vestibulum oris, a homemade metal tube was introduced into the thoracic cavity under endoscopic guidance and used as a working channel of surgical lung biopsy. TOLB was performed on the predetermined lung lobe by using an electrocautery loop and endoscopic grasper. Results. Successful surgical lung biopsy was achieved in 8 of 10 animals in a mean time of 132 minutes (range 130-190 minutes). There were no major intraoperative or postoperative complications, and all animals survived for 2 weeks after surgery. Autopsy showed no evidence of vital structure injury, mediastinitis, or empyema. Conclusions. TOLB was demonstrated to be safe and feasible in a canine model.

Gastrointestinal perforations: role of endoscopic closure

PURPOSE OF REVIEW

Understanding the role of endoscopic closure techniques helps in expanding the endoscopist's role in the management of gastrointestinal neoplasia and explore new frontiers of minimally invasive endoluminal surgery.

RECENT FINDINGS

This article covers recent advances in endoscopic closure of various gastrointestinal perforations, with a special focus on devices, experimental evidence and clinical outcomes of endoscopic closure of gastrointestinal perforations.

SUMMARY

Endoscopic closure techniques help the endoscopist to walk on thin ice and save himself and the patient in the case of mishap.

Endoscopic fixation of the rectum for rectal prolapse: a feasibility and survival experimental study

BACKGROUND

In recent years, there has been considerable interest in developing technology as well as techniques that could widen the therapeutic horizons of endoscopy. Rectal prolapse, a benign localized condition causing considerable morbidity, could be an excellent focus for new endoscopic therapies. The aim of this study was to assess the feasibility and safety of endoluminal fixation of the rectum to the anterior abdominal wall, after pushing it up inside the body, using an in vivo animal model.

METHODS

We performed an in vivo comparative surgical study in a porcine model, including laparoscopic mobilization of the rectum and posterior rectopexy (standard surgical method) or endoluminal tacking of the rectum. After proving feasibility in ex vivo and acute studies, we performed a survival study to evaluate the safety of endoluminal tacking of the mobilized rectum to the anterior abdominal wall. The main outcome measures were successful completion of the tasks, maintenance of the fixation, complications associated with the methods, and survival studies including histopathological examinations of the fixation sites.

RESULTS

There were two groups: laparoscopic rectopexy (8 animals) and endoluminal fixation of the rectum to the anterior abdominal wall (10 animals). There were no differences between these two groups in their postoperative recovery. The group with the endoluminal fixation was found to have adequate attachment of the rectum to the anterior abdominal wall (measured attachment pressure in the endoluminal group = 6.06 ± 0.52 ft-lb, in the control group = 4.86 ± 2.00 ft-lb) on both gross and microscopic evaluation.

CONCLUSION

Endoscopic fixation of the mobilized rectum is feasible and safe in this model and in the future may provide an effective alternative to current treatment options for rectal prolapse.

Natural orifice translumenal endoscopic surgery (NOTES(®)): a technical review

INTRODUCTION

The clinical NOTES literature continues to grow. This review quantifies the published human NOTES experience to date, examines instrument use in detail, and compiles available perioperative outcomes data.

METHODS

A PubMed search for all articles describing human NOTES cases was performed. All articles providing a technical description of procedures, excluding cases limited to diagnostic procedures, specimen extraction, fluid drainage or gynecological procedures, were reviewed. Two reviewers systematically cataloged the technical details of each procedure and performed a frequency analysis of instrument use in each type of case. Available outcomes data were also compiled.

RESULTS

Forty-three discrete articles were reviewed in detail, describing a total of 432 operations consisting of transvaginal (n = 355), transgastric (n = 58), transesophageal (n = 17), and transrectal (n = 2) procedures, with 90% of cases performed in hybrid fashion with laparoscopic assistance. Cholecystectomy (84% of cases) was the most common procedure. Analysis of key steps included choice of endoscope, establishment of peritoneal access, dissection, specimen extraction, and closure of the access site. Analysis of instrument use during transvaginal cholecystectomy revealed variation in the choice of endoscope and the technique for establishment of access. A majority of these procedures relied heavily on the use of rigid and transabdominal instrumentation. Closure of the vaginotomy site was found to be well standardized, performed with an open suturing technique. Similar analysis for transgastric procedures revealed consistency in the choice of flexible endoscope as well as access and closure techniques. Perioperative outcomes from NOTES procedures were reported, but the data are currently limited due to small case numbers.

CONCLUSIONS

NOTES is most commonly performed using a hybrid, transvaginal approach. Although some aspects of these procedures appear to be well standardized, there is still significant variability in technique. More outcomes data with standardized reporting are needed to determine the actual risks and benefits of NOTES.

Natural orifice translumenal endoscopic surgery (NOTES(®)): a technical review

INTRODUCTION

The clinical NOTES literature continues to grow. This review quantifies the published human NOTES experience to date, examines instrument use in detail, and compiles available perioperative outcomes data.

METHODS

A PubMed search for all articles describing human NOTES cases was performed. All articles providing a technical description of procedures, excluding cases limited to diagnostic procedures, specimen extraction, fluid drainage or gynecological procedures, were reviewed. Two reviewers systematically cataloged the technical details of each procedure and performed a frequency analysis of instrument use in each type of case. Available outcomes data were also compiled.

RESULTS

Forty-three discrete articles were reviewed in detail, describing a total of 432 operations consisting of transvaginal (n = 355), transgastric (n = 58), transesophageal (n = 17), and transrectal (n = 2) procedures, with 90% of cases performed in hybrid fashion with laparoscopic assistance. Cholecystectomy (84% of cases) was the most common procedure. Analysis of key steps included choice of endoscope, establishment of peritoneal access, dissection, specimen extraction, and closure of the access site. Analysis of instrument use during transvaginal cholecystectomy revealed variation in the choice of endoscope and the technique for establishment of access. A majority of these procedures relied heavily on the use of rigid and transabdominal instrumentation. Closure of the vaginotomy site was found to be well standardized, performed with an open suturing technique. Similar analysis for transgastric procedures revealed consistency in the choice of flexible endoscope as well as access and closure techniques. Perioperative outcomes from NOTES procedures were reported, but the data are currently limited due to small case numbers.

CONCLUSIONS

NOTES is most commonly performed using a hybrid, transvaginal approach. Although some aspects of these procedures appear to be well standardized, there is still significant variability in technique. More outcomes data with standardized reporting are needed to determine the actual risks and benefits of NOTES.

Colonic endoscopic full-thickness biopsies: from the neuropathological analysis of the myenteric plexus to the functional study of neuromuscular transmission

BACKGROUND

Better understanding of the pathophysiological mechanisms involved in severe dysmotility disorders is crucial to improve patient management and identify novel therapeutic targets. Recent studies suggested that endoscopic full-thickness biopsies (eFTBs) could be developed as an alternative to surgical biopsies. However, currently it remains unknown whether eFTBs would allow myenteric plexus analysis on whole mounts and the evaluation of neuromuscular transmission.

OBJECTIVE

To determine with eFTB specimens the ability to analyze on whole mounts the key parameters of the myenteric plexus, ie, ganglia and neurons, and to perform functional evaluation of neuromuscular transmission.

DESIGN

An experimental pilot study in 6 pigs was conducted in accordance with French institutional guidelines.

INTERVENTION

Under general anesthesia, pigs underwent a rectosigmoidoscopy. In each pig, an eFTB was performed at 25, 30, and 35 cm from the anal margin with an EMR-based technique. Tissue specimens were immediately processed for immunohistochemical and/or functional ex vivo analysis of neuromuscular transmission. In 2 pigs, over-the-scope clips were used to seal the perforation.

MAIN OUTCOME MEASUREMENTS

Feasibility of obtaining specimens containing myenteric plexus and muscularis propria, quantitative and standardized immunohistochemical evaluation of ganglia and myenteric neurons, ex vivo assessment of neuromuscular transmission and its pharmacology, and closure rate (ancillary study).

RESULTS

Adequate tissue specimens were obtained in 100% of the procedures, on average, in 6±2 minutes. Immunohistochemical analysis of a whole mount of the myenteric plexus showed that each eFTB contained 14±5 ganglia and 1562±1066 myenteric neurons. In circular muscle strips, electrical field stimulation or exposure to a pharmacological agent induced a specific tissue response. A successful closure was achieved in 50% of cases.

LIMITATIONS

Nonsurvival study; safety of the procedure needs to be specifically assessed and compared with recently published data.

CONCLUSIONS

We demonstrate, for the first time, that full-thickness biopsy specimens obtained by using an endoscopic approach allow the performance of a precise study of the ENS phenotype on whole mounts of the myenteric plexus and the performance of functional studies such as evaluation of neuromuscular transmission. However, further studies are warranted to identify the optimal and safest endoscopic procedure before application of eFTB in humans.

Gastrotomy closure with a new tissue anchoring device: A porcine survival study

AIM: To evaluate the feasibility, reproducibility and efficacy of a new tissue anchoring device in a porcine survival model.

METHODS: Gastrotomies were performed using a needle-knife and balloon dilator in 10 female Yorkshire pigs weighing 30-35 kg. Gastric closure was attempted using a new tissue anchoring device. The tightness of the closure was confirmed by means of air insufflation and the ability to maintain gastric distension with stability in peritoneal pressure measured with a Veress needle. All animals were monitored daily for signs of peritonitis and sepsis over 14 d. During necropsy, the peritoneal cavity and the gastric access site were examined.

RESULTS: Transgastric access, closure and 14 d survival was achieved in all pigs. The mean closure time was 18.1 ± 19.2 min and a mean of 2.1 ± 1 devices were used. Supplementary clips were necessary in 2 cases. The closure time was progressively reduced (24.8 ± 13.9 min in the first 5 pigs vs 11.4 ± 5.9 min in the last 5, P = NS). At necropsy, the gastric access site was correctly closed in all cases with all brace-bars present. One device was misplaced in the mesocolon. Minimal adhesions were observed in 3 pigs and signs of mild peritonitis and adhesions in one.

CONCLUSIONS: The use of this new tissue anchoring device in porcine stomachs is feasible, reproducible and effective and requires a short learning curve.

Yes, we can: reliable colonic closure with the Padlock-G clip in a survival porcine study (with video)

BACKGROUND

Secure closure of the colonic access site is one of the most important issues for the development of natural orifice transluminal endoscopic surgery.

OBJECTIVE

To evaluate the feasibility, reproducibility, and efficacy of a new over-the-scope clip.

DESIGN

Descriptive study, in vivo porcine colon.

INTERVENTION

In 10 female Yorkshire pigs weighing 30 to 35 kg, a 10-mm colotomy was performed by using a needle-knife and advancing the endoscope to the peritoneal cavity. Colonic closure was performed by using the Padlock-G clip (Aponos Medical, Kingston, NH) delivered with the Lock-It system (Aponos).

MAIN OUTCOME MEASUREMENTS

Animals were monitored daily for signs of peritonitis and sepsis over a period of 14 days. During necropsy, the peritoneal cavity was examined, and the colon segment containing the incision was excised for pathological study.

RESULTS

Closure was achieved in all cases. Nine of 10 pigs survived 14 days without complications, but 1 pig was killed immediately after the procedure because of severe bleeding during the colonic incision. The median closure time was 8 minutes (range 1-30 minutes). At necropsy, adhesions were observed in 5 cases. The incision was hardly visible at the serosa side in 3 cases and was not identified in 6 cases. In 6 cases, the clip was still slightly attached to the mucosa, and it was not found in 3 cases. The pathological study revealed a complete remodeling of the colonic wall in all cases.

LIMITATIONS

Animal model, noncomparative study.

CONCLUSION

The Padlock-G clip procedure is feasible, reproducible, effective, and easy to perform, and it provides a reliable colonic closure.