Endoluminal methods for gastrotomy closure in natural orifice transenteric surgery (NOTES)

Laparoscopic surgery versus open resection in patients with gastrointestinal stromal tumors: An updated systematic review and meta-analysis

PURPOSES

The contemporary surgery has reported the safety of laparoscopic surgery (LAP) for patients with gastrointestinal stromal tumors (GISTs). However, its use is still debated due to suspicion of the oncologic equivalence to open surgery (OPEN). We conducted a systematic review and meta-analysis of updated original articles to investigate the short- and long-term clinical outcomes of LAP compared with OPEN for GISTs.

METHODS

A systematic search was performed in PubMed, Embase, Web of Science, Cochrane Library and CNKI. Comparative studies of laparoscopic and open surgery for GISTs were published before November 2016. The Newcastle-Ottawa scale was utilized to conduct quality assessment. The Review Manager (RevMan) software version 5.0 was used for meta-analysis.

RESULTS

Twenty-four studies involving 2140 patients were included for the meta-analysis. The meta-analysis results showed that, compared with OPEN, LAP indicated potentially favorable outcomes in terms of operative time (WMD, -30.71; 95% CI, -58.48 to -2.95; P = 0.03); intraoperative blood loss (WMD, -60.90; 95% CI, -91.53 to -30.28; P < 0.0001); time to flatus (WMD, -1.10; 95% CI, -1.41 to -0.79; P < 0.00001); time to oral intake (WMD, -1.25; 95% CI, -1.64 to -0.86; P < 0.00001); length of hospital stay (WMD, -3.42; 95% CI, -4.37 to -2.46; P < 0.00001); overall complications (OR, 0.38; 95% CI, 0.27 to 0.54; P < 0.00001); and recurrence (OR, 0.45; 95% CI, 0.30 to 0.66; P < 0.0001).

CONCLUSIONS

Laparoscopic surgery is safe and feasible for the treatment of GISTs including less operative time and intraoperative blood loss, earlier postoperative recovery, shorter hospital stay, and lower rate of overall complications and recurrence.

Choice of handedness and automated suturing for anthropomorphic dual-arm surgical robots

Laparoscopic and Single Port Access Surgery (SPAS) present unique dexterity challenges related to dual-arm operations in confined spaces and tele-manipulation of highly dexterous surgical slaves. In an effort to reduce tele-manipulation burden, new paradigms for semi-automating surgical tasks are needed. This paper presents a new minimal constraint suturing and automated choice of handedness for anthropomorphic dual-arm robots. The automated choice of handedness supports surgeons during tele-manipulation of complex robotic slaves where dexterity and workspace constraints are difficult to learn. This criterion is also used to support automated dual-arm rendezvous for quicker suture exchange during dual-arm suturing. The minimal constraint algorithm presented in this paper allows surgeons to operate within a shared-control tele-manipulation framework whereby the surgeon controls the needle insertion speed and the robot controls the needle orientation while respecting a minimalistic set of tissue constraints. This framework is evaluated on a novel insertable robotic end-effectors platform for SPAS. A simulation study demonstrates the effectiveness of the automated choice of handedness criterion through a study of dexterity limitations of each arm. Additional simulations show the proposed algorithm for automated rendezvous and suture exchange.

Beyond the "B": a new concept of the surgical staple enabling miniature staplers

Background

Surgical staplers currently all rely on the same staple form—the “B” which necessitates a high delivery profile (12 mm). A novel “D” shape staple allows for an extremely low profile of the applicator. The acute and long-term efficacy of a D-shaped staple (Cardica, Redwood City, CA, USA) was compared to conventional B-form staples (Covidien, Norwalk, CN, USA) in an animal model for intestinal transections and anastomoses.

Methods

Jejunojejunal anastomoses (JJ) were performed via mini-laparotomy in a swine model. White & blue D- and B-shaped staples were studied in three groups (planned survival 14–84 days). Intraoperative assessment included completeness of staple line, hemostasis, and need for intervention. Postoperatively, animals were evaluated for complications. At the time of sacrifice, gross pathological and histological assessments were performed.

Results

Twenty-three animals had 40 anastomoses (23 “D” and 17 “B” staple anastomoses) with no intraoperative mortalities. One “D” staple application required a manual extension of the cut. Acute hemostasis was 100 %. Group 1 (n = 5) compared white staples in JJs (D staple n = 5; B staple n = 5; 14-day survival = 100 %). Group 2 (n = 12) compared white staples in JJs (D staple n = 12; B staple n = 6; 34-day survival = 92 %). One animal died on day 4 for a non-staple related cause. Group 3 (n = 6) compared blue staples in JJs (D staple n = 6; B staple n = 6; 84 day survival = 84 %). One animal died on day 18 due to an obstruction at the B staple JJ caused by stricture. There were no other bleeding, leaks or strictures in any of the groups. Gross pathology and histology were unremarkable in all JJs.

Conclusions

This study showed no difference in intraoperative performance and the chronic healing response in JJs between D- and B-shaped staples. Based on these findings, the D-shaped staple elicits a normal healing response in jejunostomies and offers the possibility of clinical use of this advance in staple design.

In vivo assessment of a biological occluder for NOTES gastrotomy closure

BACKGROUND

The objective of this study is to evaluate the closure of a transgastric natural orifice transluminal endoscopic surgery (NOTES) access using a multilayer extracellular matrix (ECM) occluder in a canine model.

MATERIALS AND METHODS

Mongrel dogs (n = 4) underwent a transgastric NOTES peritoneoscopy and the gastrotomy was closed by deploying a 2-sided ECM occluder. Animals were killed at 7 days (n = 2) and 8 weeks (n = 2) for macroscopic and microscopic assessment.

RESULTS

All procedures were completed without any complications. No air leaks were detected immediately after the procedure and at 48 hours postoperatively. At 7 days, ECM appeared to be resolved and mild mucosal inflammation was found at the site of gastrotomy. At 8 weeks, the gastrotomy site was macroscopically and microscopically covered with a normal-appearing gastric mucosa. There was an absence of inflammatory cells and no evidence of the ECM.

CONCLUSION

The ECM occluder is safe and effective in this "proof-of-concept" preclinical model.

Early experience with the Incisionless Operating Platform™ (IOP) for the treatment of obesity : the Primary Obesity Surgery Endolumenal (POSE) procedure

BACKGROUND

We report our initial experience and 6-month outcomes in a single center using the per-oral Incisionless Operating Platform™ (IOP) (USGI Medical) to place transmural plications in the gastric fundus and distal body using specialized suture anchors (the Primary Obesity Surgery Endolumenal [POSE] procedure).

METHODS

A prospective observational study was undertaken with institutional Ethics Board approval in a private hospital in Barcelona, Spain. Indicated patients were WHO obesity class I-II, or III, where patients refused a surgical approach.

RESULTS

Between February 28, 2011 and March 23, 2012, the POSE procedure was successfully performed in 45 patients: 75.6 % female; mean age 43.4 ± 9.2 SD (range 21.0-64.0). At baseline: mean absolute weight (AW, kg), 100.8 ± 12.9 (75.5-132.5); body mass index (BMI, kg/m(2)), 36.7 ± 3.8 (28.1-46.6). A mean 8.2 suture-anchor plications were placed in the fundus, 3.0 along the distal body wall. Mean operative time, 69.2 ± 26.6 min (32.0-126.0); patients were discharged in <24 h. Six-month mean AW was 87.0 ± 10.3 (68.0-111.5); BMI decreased 5.8 to 31.3 ± 3.3 (25.1-38.6) (p < 0.001); EWL was 49.4 %; TBWL, 15.5 %. No mortality or operative morbidity. Minor postoperative side effects resolved with treatment by discharge. Patients reported less hunger and earlier satiety post procedure. Liquid intake began 12 h post procedure with full solids by 6 weeks.

CONCLUSIONS

At 6-month follow-up of a prospective case series, the POSE procedure appeared to provide safe and effective weight loss without the scarring, pain, and recovery issues of open and laparoscopic bariatric surgery. Long-term follow-up and further study are required.

Early experience with the Incisionless Operating Platform™ (IOP) for the treatment of obesity : the Primary Obesity Surgery Endolumenal (POSE) procedure

BACKGROUND

We report our initial experience and 6-month outcomes in a single center using the per-oral Incisionless Operating Platform™ (IOP) (USGI Medical) to place transmural plications in the gastric fundus and distal body using specialized suture anchors (the Primary Obesity Surgery Endolumenal [POSE] procedure).

METHODS

A prospective observational study was undertaken with institutional Ethics Board approval in a private hospital in Barcelona, Spain. Indicated patients were WHO obesity class I-II, or III, where patients refused a surgical approach.

RESULTS

Between February 28, 2011 and March 23, 2012, the POSE procedure was successfully performed in 45 patients: 75.6 % female; mean age 43.4 ± 9.2 SD (range 21.0-64.0). At baseline: mean absolute weight (AW, kg), 100.8 ± 12.9 (75.5-132.5); body mass index (BMI, kg/m(2)), 36.7 ± 3.8 (28.1-46.6). A mean 8.2 suture-anchor plications were placed in the fundus, 3.0 along the distal body wall. Mean operative time, 69.2 ± 26.6 min (32.0-126.0); patients were discharged in <24 h. Six-month mean AW was 87.0 ± 10.3 (68.0-111.5); BMI decreased 5.8 to 31.3 ± 3.3 (25.1-38.6) (p < 0.001); EWL was 49.4 %; TBWL, 15.5 %. No mortality or operative morbidity. Minor postoperative side effects resolved with treatment by discharge. Patients reported less hunger and earlier satiety post procedure. Liquid intake began 12 h post procedure with full solids by 6 weeks.

CONCLUSIONS

At 6-month follow-up of a prospective case series, the POSE procedure appeared to provide safe and effective weight loss without the scarring, pain, and recovery issues of open and laparoscopic bariatric surgery. Long-term follow-up and further study are required.

Application of design rationale for a robotic system for single-incision laparoscopic surgery and natural orifice transluminal endoscopic surgery

Current endoscopes and instruments are inadequate in some respects for complex intra-abdominal surgery because they are too flexible and cannot provide robust grasping and anatomic retraction. Minimal invasive surgery devices represent a sophisticated class of mechanical instruments making use of a range of mechanisms integrated into modular platforms that can be combined to undertake complex medical procedures. Although the machine elements concerned represent classic mechanical engineering devices, issues of miniaturization, surgical procedure compliance and location control conspire to present a design challenge. In order to capture, document and resolve the design requirements for this complex application, quality functional deployment has been applied in combination with design rationale, captured through issue-based information system mapping. This article reports the use of these tools to produce robot designs with improved dexterity and triangulation that are basic requirements in laparoscopy.

Safety and effectiveness of an endoscopic suturing device in a human colonic treat-and-resect model

BACKGROUND

Despite advances in many areas of therapeutic endoscopy, the development of an effective endoscopic suturing device has been elusive. The purpose of this trial was to evaluate the safety and effectiveness of a suturing device to place and secure sutures within normal, in vivo human colonic tissue prior to surgical resection.

METHODS

Patients undergoing elective colectomy were enrolled in this treat-and-resect model. The Overstitch endoscopic suturing device (Apollo Endosurgery, Austin, TX) was used to place sutures in healthy colonic tissue during a 15-minute, time-limited period. Following colectomy, the explanted tissue was evaluated to determine the depth of suture penetration and the effectiveness of the suture/cinch element. Clinical and operative data were recorded.

RESULTS

Four patients (50% female) were enrolled. Seven sutures were successfully placed, incorporating a total of 10 tissue bites in a mean of 13.5 minutes. On inspection of the explanted tissue, all sutures were found to be located subserosal (no full thickness bites were taken). The suture and cinch elements were judged to be effective in the majority of cases. One device-related issue did not inhibit the ability to oppose tissue or place the cinch. There were no intraoperative or postoperative complications.

CONCLUSIONS

The Overstitch permitted safe and effective suturing in an in vivo human colon model. The sutures were placed at a consistent subserosal depth and at no point risked iatrogenic injury to adjacent structures. Technical issues with the device were infrequent and did not inhibit the ability to place sutures effectively.

Mechatronic design of a fully integrated camera for mini-invasive surgery

This paper describes the design features of an innovative fully integrated camera candidate for mini-invasive abdominal surgery with single port or transluminal access. The apparatus includes a CMOS imaging sensor, a light-emitting diode (LED)-based unit for scene illumination, a photodiode for luminance detection, an optical system designed according to the mechanical compensation paradigm, an actuation unit for enabling autofocus and optical zoom, and a control logics based on microcontroller. The bulk of the apparatus is characterized by a tubular shape with a diameter of 10 mm and a length of 35 mm. The optical system, composed of four lens groups, of which two are mobile, has a total length of 13.46 mm and an effective focal length ranging from 1.61 to 4.44 mm with a zoom factor of 2.75×, with a corresponding angular field of view ranging from 16° to 40°. The mechatronics unit, devoted to move the zoom and the focus lens groups, is implemented adopting miniature piezoelectric motors. The control logics implements a closed-loop mechanism, between the LEDs and photodiode, to attain automatic control light. Bottlenecks of the design and some potential issues of the realization are discussed. A potential clinical scenario is introduced.

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.

Laparoscopic assisted transvaginal cholecystectomy: single centre preliminary experience

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Single loop-and-clips technique (KING closure) for gastrotomy closure after transgastric ovariectomy: a survival experiment

Introduction

A safe closure technique of transluminal access is essential for the widespread application of natural orifice transluminal endoscopic surgery (NOTES).

Aim

To evaluate the feasibility and effectiveness of a novel single loop-and-clips closure technique (KING closure).

Material and methods

An experimental survival study using female laboratory pigs was performed. A gastrotomy was performed using a standard percutaneous endoscopic gastrostomy technique. A peritoneoscopy with an ovariectomy was then performed with a double-channel endoscope, on a total of 14 pigs. Two different techniques of gastrotomy closure were analysed: a loop-and-clips closure technique (n = 7) and a standard closure using endoclips (n = 7). After a follow-up period of 30 days, the animals were euthanized for post-mortem examination.

Results

In the “loop-and-clip” closure group, the correct placement of an endoloop and clips was achieved in all animals. At necropsy, no animal showed signs of an abscess or peritonitis. Histological examination demonstrated a patent full-thickness gastric wall closure without evidence of local complications in all instances. In the “clips” group, the gastrotomy closure was assessed as probably unsafe in three animals. At necropsy 3 (42.9%) abscesses and 1 (14.3%) case of peritonitis were found.

Conclusions

A single loop-and-clips closure technique (KING closure) represents a feasible, simple and effective method of gastric incision closure. It appears to be superior to the standard endoscopic closure technique using clips.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Optimizing surgical approach for natural orifice translumenal endoscopic procedures

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) often requires some degree of retroflexion of the endoscopic operating system. This study investigates the impact of retroflexion on task performance in NOTES.

METHODS

In a bench-top simulation, surgeons were required to manipulate a single-channel endoscope to touch 4 dots in a predetermined order. The task was performed under the forward-view and retroflexed-view conditions.

RESULTS

Tasks performed under the forward-view condition were significantly faster than those performed under the retroflexed-view condition (P = .005). Also, 5 experienced surgeons completed tasks in less time than the novices (P = .043). Experienced surgeons were mildly affected by the inverted image, whereas the novices were vulnerable to image malalignment.

CONCLUSION

Careful selection of the surgical approach to avoid image malalignment is suggested for safe performance of NOTES. Extensive training is required for novices to overcome the vision-motion difficulty before they can perform NOTES safely and effectively.

Natural Orifice Surgery (NOS)-the next step in the evolution of minimally invasive surgery

Endoscopy, which was introduced in the 20(th) century, changed the outcome of surgery by reducing the need for analgesia and shortening hospital stay. Any new surgical method should improve safety and outcome. At the beginning of the 21(st) century, the use of natural orifice surgery is a promising progress. The transgastric and transdouglas approaches are currently being investigated and evaluated. The transgastric approach still has a long way to go due to objective problems such as infections, stomach acidity, and the optimal way to ensure the safe closure of gastrotomy. The transdouglas approach, however, is already starting to establish itself and it seems that with the construction of designated instruments it will prevail in the 21(st) century.

Transgastric endoscopic pneumoperitoneum versus laparoscopy: effects on host systemic and peritoneal inflammatory responses in a porcine model

BACKGROUND

The host systemic and peritoneal immune responses during natural orifice transluminal endoscopic surgery (NOTES) continues to be delineated. The immune response to laparoscopy (LAP) has been favorably depicted. However, the immunologic effects of NOTES are yet to be determined, and the introduction of contaminants via the host orificium may have deleterious effects. The purpose of this study was to characterize the effect that NOTES would have on porcine systemic and peritoneal immune function.

METHODS

Twenty-four pigs were divided into three groups: ENDO (upper-endoscopy control), NOTES, and LAP. All animals had blood and peritoneal lavage samples collected for cytokine analysis pre- and postoperatively. Interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNFα), and interferon γ (IFNγ) levels were quantified using enzyme-linked immunosorbent assay (ELISA). Peritoneal lavage samples were cultured and identified by group and time of collection for microbiological analysis.

RESULTS

TNFα was found in detectable levels in serum samples of all three groups. For the NOTES group, there was a significant increase in TNFα at t = 1 h (P < 0.01), which dropped significantly at t = 48 h (P < 0.01). IL-1β was present as an early response in NOTES lavage samples (t = 0 and t = 1 h). Both LAP and NOTES had similar elevation of IL-1β in the final lavage samples at t = 48 h. The other cytokines were not consistently found above detectable levels in any group. Similar microbiological contaminants were found in the ENDO and LAP groups. In the NOTES group, no significant growth was observed from cultures at 48 h.

CONCLUSIONS

For measurable cytokines, the NOTES inflammatory response was not significantly different from that of the LAP group. NOTES did not carry a significantly increased amount of microbiological contamination at 48 h compared to LAP. These data suggest that the host immune response to NOTES does not significantly differ from that to LAP in a porcine model.

Endoscopic treatment for gastric perforation using T-tag and a plastic protection chamber: a short-term survival study

CONTEXT: The endoscopic gastric perforation is a consequence of some endoscopic procedures and now a way to manage abdominal organs. This is the reason why endoscopists are studying a safe endoscopic repair. OBJECTIVE: To evaluate an endoscopic closure method for the gastric opening in natural orifice transenteric surgery DESIGN: Short-term survival animal study. METHODS: Ten White Landrace pigs underwent a gastric perforation of 1.8 cm in diameter under general anesthesia. The opening was repaired with stitch assembled in a T-tag anchor placed through the gastric wall with a needle. A plastic transparent chamber, adapted to the endoscope tip protected the abdominal organs from the needle puncture outside the stomach. Six T-tags were placed in most cases and the stitches were tied with a metallic tie-knot, forming three sutures. The animals received liquids in the same operative day. One shoot antibiotic was used. The leakage test was performed with a forceps and by air distention. RESULTS: No complication was detected in the postoperative course. One month later the endoscopy revealed a scar and some suture material was observed in all animals. The antral anterior gastric wall was clear with few adhesions in the laparotomy performed in the same time. The adhesions were intense in an animal in which a cholecystectomy was performed before the repair. CONCLUSION: The endoscopic repair using T-tag and a protector chamber is feasible, easy to perform and safe. Further studies are needed to show the real value of this kind of procedure.

Initial experience from the transgastric endoscopic peritoneoscopy and biopsy: a stepwise approach from the laboratory to clinical application

BACKGROUND AND AIM

Natural-orifice translumenal endoscopic surgery (NOTES) is a newly minimally invasive technique that gives access to the abdominal cavity via transgastric, transcolonic, transvaginal or transvesical routes. The aim of the present study was to evaluate the safety and feasibility of transgastric endoscopic peritoneoscopy and biopsy from laboratory to clinical application.

METHODS

With the animals under general anesthesia, a sterile esophageal overtube was placed and a gastric antibiotic lavage was performed. Subsequently, a needle-knife and through-the-scope dilating balloon were used to make an anterior gastric wall incision through which a therapeutic gastroscope was advanced into the peritoneal cavity. After 2 weeks, another transgastric endoscopic exploration was performed in a different location of the stomach. The peritoneal cavity was examined before the gastric incision was closed. After 4 weeks of observation, necropsy was performed. In the clinical application, after gastric lavage, the first step was the creation of the gastrotomy under general anesthesia, sometime under direct vision of the laparoscopic scope. Then the endoscope can be maneuvered in the peritoneal cavity. And peritoneoscopy and biopsy were performed. Biopsies can be obtained from any suspicious areas using punch biopsy forceps. The gastrotomy was then closed with clips. The gastroscopy was examined after one week.

RESULTS

Twenty-eight transgastric endoscopic peritoneoscopies and biopsies in pigs and a total of five transgastric human endoscopic peritoneoscopies and biopsies have been performed. All procedures were completed satisfactorily in the pig model and all patients. There were no intraoperative or postoperative complications.

CONCLUSIONS

The advantages of peritoneoscopy and biopsy appeared to be enhanced by this approach. Patients had minor postoperative pain and minimal scarring. It is safe and feasible for us to use transgastric endoscopic peritoneoscopy and biopsy in humans.

Laparoscopic-assisted endoluminal hybrid surgery: a stepping stone to NOTES

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) is the anticipated progression of minimally invasive surgery. As it approaches, surgeons will need to develop the fundamental skills and spatial orientation needed to perform safely in this new field. The Natural Orifice Surgery Consortium for Assessment and Research has established several fundamental challenges to the safe introduction of NOTES. Our institutional experience with laparoscopic-assisted endoluminal surgery is reviewed to display the techniques and efficacy of procedures that address many of these challenges and may provide a safe transition for the general surgeon to NOTES or as an alternative to pure NOTES.

METHODS

A retrospective review of all laparoscopic-assisted endoluminal surgeries from 1991 to 2007 was performed. Patients had been referred to the institution and selected after either unsuccessful attempts from traditional endoscopic resection of pathology by a gastroenterologist or being deemed an unfavorable candidate for traditional endoscopic resection. All procedures involved establishment of pneumoperitoneum, placement of trochar ports under laparoscopic visualization, balloon ports in gastric cases combined with endoscopy, intraluminal insufflation, coordinated resection of intraluminal pathology using both the endoscopic and laparoscopic instruments, and closure of the intraluminal port sites with intracorporeal suturing.

RESULTS

A total of 175 procedures were performed from 1991 to 2007 using these techniques. These procedures varied and included laparoscopic monitored colonoscopic polypectomy, resection of gastric polyps, intraluminal cystgastrostomy, gastric ulcer resection, and foreign body removal. The average age was 55 years (range 38 to 75 y), length of operation 95 minutes (range 60 to 137 min), hospital stay 3.5 days, and 5 complications (2.8%). Of the total procedures, 18 (10.2%) patients were found to have malignancy on frozen section and preceded with a formal resection. There are no cancer recurrences to date with a mean follow up of 74 months (6 to 196 mo).

CONCLUSIONS

Our institutional experience with these procedures seems to be a natural transition to developing skills for NOTES procedures and displays a safe and effective approach to a wide range of intraluminal pathology. The general surgeon in practice can use this union of laparoscopy and endoscopy using current instruments and technology for safe transition into the emerging field of NOTES, or even as an alternative to pure NOTES. Mastery of intraoperative endoscopy and intraluminal surgery will be essential to this transition.

Single-Port Laparoscopic Cholecystectomy With the X-Cone: A Feasibility Study in 9 Pigs

Objective: Virtually any port system for single-port laparoscopic surgery is for single usage only. The aim of this study was to trial the novel and completely reusable port X-Cone in order to perform a cholecystectomy by one infraumbilical incision. Methods: Single access cholecystectomies were performed in 9 anesthetized domestic pigs in nonsurvival studies. Only one infraumbilical incision was performed for placing the reusable, multichannel steel port system. A newly developed angulated forceps was used besides regularly used instruments in laparoscopic surgery. Results: The gallbladder was successfully removed in 9 pigs. At postmortem examination, the clips placed on the cystic duct and the cystic artery. No bile leakage was found at the operative field. Conclusion: Single-port cholecystectomy with the reusable X-Cone single-port system is safe and feasible. No additional incisions were needed. The system is ergonomically designed, easy to handle, and the learning curve for cholecystectomy is steep.

Endoscopic closure of GI fistulae by using an over-the-scope clip (with videos)

BACKGROUND

Preclinical studies have demonstrated the over-the-scope clip (OTSC) to be feasible and safe for closure of gastric, duodenal, and colonic perforations. A retrospective clinical study demonstrated the feasibility and preliminary safety of the OTSC for the treatment of GI bleeding and closure of acute GI perforations.

OBJECTIVE

Because the OTSC allows rapid and easy endoscopic organ wall closure, we hypothesized that it might be a useful tool to close GI fistulae.

DESIGN

Case series.

SETTING

Academic medical center.

PATIENTS

Four consecutive patients with GI fistulae.

INTERVENTIONS

In all patients, a 12-mm OTSC, in combination with the dedicated twin grasper, anchor device, or endoscopic suction, was used to facilitate endoscopic closure.

MAIN OUTCOME MEASUREMENTS

In 2 cases, OTSCs allowed complete closure of a posttraumatic esophagopulmonary fistula and a chronic gastrocutaneous fistula. Leak tests and follow-up examination demonstrated complete leakproof closures. In 1 esophagopulmonary fistula and 1 jejunocutaneous fistula, the initial closure attempts using OTSCs were not successful because of chronic fibrotic changes and scarring at the fistula site. Both OTSCs were removed by using an endoscopic grasping forceps. The mean procedure time was 54 minutes (range 24-93 minutes). There were no procedure-related complications.

LIMITATIONS

Small sample size.

CONCLUSIONS

The OTSC seems to be a feasible device to close chronic fistulae of the GI tract. It can achieve leakproof, full-thickness closure of transmural defects. Nevertheless, in circumstances of severe fibrosis and scarring, complete incorporation of the defect into the applicator cap and successful OTSC application might not be possible.

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.

International multicenter trial on clinical natural orifice surgery--NOTES IMTN study: preliminary results of 362 patients

OBJECTIVES

Natural orifice translumenal endoscopic surgery (NOTES) is evolving as a promising alternative for abdominal surgery. IMTN Registry was designed to prospectively document early results of natural orifice surgery among a large group of clinical cases.

METHODS

Sixteen centers from 9 countries were approved to participate in the study, based on study protocol requirements and local institutional review board approval. Transgastric and transvaginal endoscopic natural orifice surgery was clinically applied in 362 patients. Intraoperative and postoperative parameters were prospectively documented.

RESULTS

Mean operative time for transvaginal cholecystectomy was 96 minutes, compared with 111 minute for transgastric cholecystectomy. A general complication rate of 8.84% was recorded (grade I-II representing 5.8%, grade III-IV representing 3.04%). No requirement for any analgesia was found in one fourth of cholecystectomy and appendectomy patients.

CONCLUSIONS

Results of clinical applications of NOTES in the IMTN Study showed the feasibility of different methods of this new minimally invasive alternative for laparoscopic and open surgery.

Clinical experience with a multifunctional, flexible surgery system for endolumenal, single-port, and NOTES procedures

BACKGROUND

Single-port and incisionless surgical approaches hold the promise of fewer complications, reduced pain, faster recovery, and improved cosmesis compared with traditional open or laparoscopic approaches. The ability to select an access approach (i.e., endolumenal, single-port, transvaginal, or transgastric) with one platform may be important to optimization of individual patient results. The authors report their results using these four separate surgical approaches tailored to three different therapeutic procedures, all with the use of a single flexible platform, the Incisionless Operating Platform (IOP).

METHODS

After institutional review board approval, the IOP was used to perform nine cholecystectomies via transvaginal (TV) (n=4), transgastric (TG) (n=4), and single-port transumbilical (TU) (n=1) access. Two appendectomies were performed via TG access. Endolumenal access was used for 18 gastric pouch and stoma reductions after Roux-en-Y gastric bypass. The TG and TV procedures involved the use of one to three trocars. The recorded data included safety, procedural success, operative time, patient pain assessment (on a 0-10 scale) at discharge, and length of hospital stay.

RESULTS

Procedural success was achieved for 16 of 18 endolumenal procedures, 1 of 1 single-port procedure, and 10 of 10 NOTES procedures. For 5 of 10 NOTES procedures, only one small trocar was required. The mean operative times were 79 min for pouch with stoma reduction, 171 min for cholecystectomy, and 274 min for appendectomy. Of 29 patients, 27 were discharged in 24 h or less. The average pain scores were 0.44 for pouch with stoma reduction, 1.3 for cholecystectomy, and 2.5 for appendectomy. No significant complications occurred. The ergonomics of IOP allowed the surgeon to interface with the system using an endoscopic or laparoscopic orientation.

CONCLUSION

Availability of a multifunctional, flexible surgery platform provides a choice of a single-port or incisionless surgical approach with the potential to reduce complications, pain, and recovery time while improving cosmesis.

Durability of the self-approximating translumenal access technique (STAT) for potential use in natural orifice translumenal surgery (NOTES)

BACKGROUND

The self-approximating translumenal access technique (STAT) has been shown to provide a safe and reliable means of abdominal access for natural orifice translumenal endoscopic surgery (NOTES). However, the feasibility of using STAT for translumenal organ resection is unknown. This study aimed to evaluate the technical performance of organ resection using STAT, the integrity of the STAT gastric tunnel after organ resection, and the postoperative morbidity of organ resection using STAT.

METHODS

In this study, 14 domestic swine underwent transgastric organ resection (7 cholecystectomies, 7 uterine horn resections) followed by sequential removal of two different sizes of standardized specimens. Evaluation of operative injury to the tunnel and difficulty of specimen extraction was performed. After 2 weeks of observation, necropsy was performed for evaluation and documentation of gross findings.

RESULTS

The mean operating room time (intubation recovery) was 4.1 h. A tunnel with a mean length of 12 cm and a mean width of 4 cm was created. The tunnel remained fully intact in 14 of 14 animals after organ resection, in 13 of 13 animals after balloon extraction, and in 12 of 14 animals after rigid specimen extraction (1 clinically significant tear occurred). Postoperatively, all the animals gained weight appropriately. Necropsy findings included adhesions (n = 4), bile leak (n = 2), minor lap-port abscess (n = 1), and ventral hernia (n = 1).

CONCLUSIONS

Although this study was a limited, prospective, animal survival study without a control arm, it again indicates that STAT allows safe abdominal access, a reliable means of closure, and directed endoscope positioning. Although one significant mucosal tear did occur, this study suggests STAT will tolerate the mechanical forces of peroral transgastric procedures provided the organ resected is small to moderate in size (<8 × 3 cm).

Esophagogastroduodenoscopy-associated gastrointestinal perforations: a single-center experience

BACKGROUND

Esophagogastroduodenoscopy (EGD) is commonly used in the diagnosis and treatment of gastrointestinal (GI) disorders. Our aim was to define the risk of perforation associated with EGD and identify patients who required operative intervention.

METHODS

We retrospectively reviewed 72 patients from our institution plus 5 transferred patients who sustained EGD-associated perforations from January 1996 through July 2008. Percutaneous endoscopic gastrostomy, endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, transthoracic echocardiography, and concurrent colonoscopy procedures were excluded.

RESULTS

Perforations in 72 of 217,507 EGD procedures were identified (incidence, 0.033%); 124,844 EGDs included an interventional procedure and 92,663 were examination only. The incidence of perforation was similar whether an interventional procedure was performed or not (0.040% vs 0.029%; P = .181). The esophagus was injured most commonly (51%), followed by the duodenum (32%), jejunum (6%), stomach (3%), and common bile duct (3%). Overall mortality after perforation was 17% with a morbidity rate of 40%. Thirty-eight patients (49%) were initially treated nonoperatively, 7 of whom (18%) failed nonoperative management. The only factors we could determine that were associated with failure were free fluid or contrast extravasation on computed tomography (75% vs 23% [P < .005] and 33% vs 0% [P = .047], respectively). The morbidity of failures was equivalent to those who underwent initial operative management (63% vs 61%; P = .917), with mortality seeming to be greater (43% vs 21%; P = .09).

CONCLUSION

EGD is safe in the majority of patients; however, iatrogenic perforation is associated with considerable morbidity and mortality. Nonoperative management of GI perforation can be successful if there is no evidence of contrast extravasation or free fluid on radiographic studies. If nonoperative management fails, the outcomes may be worse than those treated initially with operative repair.

Transgastric organ resection solely with the prototype R-scope and the self-approximating transluminal access technique

BACKGROUND

The self-approximating transluminal access technique (STAT) has been demonstrated to provide safe transluminal access and in-line endoscope positioning to target abdominal organs during natural orifice transluminal endoscopic surgery (NOTES). To date, organ resection with NOTES has typically required percutaneous assistance. We hypothesized that the in-line positioning and partial stability provided by STAT would allow single-access NOTES procedures if a multiarticulated endoscope could be used.

OBJECTIVE

Assessment of single-site NOTES, using STAT and a prototype, multi-articulated endoscope.

DESIGN

Animal survival study.

SETTING

Penn State Hershey Medical Center Research Laboratories.

INTERVENTIONS

Thirteen pigs underwent NOTES using a prototype endoscope with 2 articulated channels, a grasping forceps, and an insulated-tip needle-knife. The gallbladder was dissected using a fundus down technique, and hemoclips and a detachable loop were placed on the cystic duct and artery before removal. After a 2- to 3-week observation period, animals were euthanized and necropsy performed.

RESULTS

All target organs were successfully resected without laparoscopic assistance. Significant complications were 2 perforations (1 caused by a prototype duodenal occlusion device and 1 caused by enterotomy during cholecystectomy) and 1 entrapment of the small bowel with an endoloop. Postoperatively, all animals gained weight appropriately with 1 killed on postoperative day 12 because of lethargy (cystic duct leak/biloma).

LIMITATIONS

This is a limited animal survival study without control arm.

CONCLUSIONS

The combination of the R-scope and STAT does allow effective, single-site NOTES procedures; however, although the R-scope provides improved tissue manipulation and visibility, the complications incurred here suggest that further improvements in devices and technique will be required for safe and effective single-site NOTES procedures.

Do gastrotomies require repair after endoscopic transgastric peritoneoscopy? A controlled study

BACKGROUND

The optimal method for closing gastrotomies after transgastric instrumentation has yet to be determined.

OBJECTIVE

To compare gastrotomy closure with endoscopically delivered bioabsorbable plugs with no closure.

DESIGN

Prospective, controlled study.

SETTING

Animal laboratory.

SUBJECTS

Twenty-three dogs undergoing endoscopic transgastric peritoneoscopy between July and August 2007.

INTERVENTIONS

Endoscopic anterior wall gastrotomies were performed with balloon dilation to allow passage of the endoscope into the peritoneal cavity. The plug group (n = 12) underwent endoscopic placement of a 4 x 6-cm bioabsorbable mesh plug in the perforation, whereas the no-treatment group (n = 11) did not. Animals underwent necropsy 2 weeks after the procedure.

MAIN OUTCOME MEASUREMENTS

Complications related to gastrotomy closure, gastric burst pressures, relationship of burst perforation to gastrotomy, and the degree of adhesions and inflammation at the gastrotomy site.

RESULTS

After the gastrotomy, all dogs survived without any complications. At necropsy, burst pressures were 77 +/- 11 mm Hg and 76 +/- 15 mm Hg (P = .9) in the plug group and no-treatment group, respectively. Perforations occurred at the site of the gastrotomy in 2 of 12 animals in the plug group and in none of the 11 dogs in the no-treatment group (P = .5). Finally, there were minimal adhesions in all dogs (11/11) in the no-treatment group and minimal adhesions in 3 and moderate adhesions or inflammatory masses in 9 of the 12 animals in the plug group (P = .004).

LIMITATIONS

Small number of subjects, animal model, no randomization. Gastrotomy trauma during short peritoneoscopy may not be applicable to longer procedures.

CONCLUSIONS

After endoscopic gastrotomy, animals that were left untreated did not show any clinical ill effects and demonstrated adequate healing, with fewer adhesions and less inflammation compared with those treated with a bioabsorbable plug.

Endoscopic mucosal resection with full-thickness closure for difficult polyps: a prospective clinical trial

BACKGROUND

Large flat polyps may be more amenable to endoscopic resection if an endoluminal method for full-thickness closure were available.

OBJECTIVE

Assessment of feasibility of endoluminal full-thickness closure.

DESIGN

Prospective, open-label, interventional study.

SETTING

Tertiary referral center.

PATIENTS

Patients referred to surgery for endoscopically unresectable polyps.

INTERVENTIONS

Endoscopic resection of colon polyps with full-thickness closure of the resection site under laparoscopic observation by using a novel needle and T-tag tissue apposition system.

MAIN OUTCOME MEASUREMENTS

Feasibility and efficacy of tissue apposition with the TAS during procedure and safety at 3-month follow-up.

RESULTS

Nineteen patients referred with unresectable polyps at initial colonoscopy were enrolled. Five patients had successful endoscopic polypectomy and did not require closure of the resulting defect. In 6 patients, the polyp could not be resected endoscopically and surgical resection was performed. Use of the TAS was attempted in 8 and successfully deployed in 7 patients; there was 1 device malfunction. Deployment of the tags through the needle could be performed more safely under laparoscopic guidance when the resection site was visible from the peritoneal cavity. The location of the tags could not be safely determined when the needle was directed toward the retroperitoneal or mesenteric site. There were no long-term complications. Colonoscopy at a 3-month follow-up showed normal healed mucosa with the sutures and anchoring devices in place.

LIMITATIONS

Small number of patients, single-center feasibility study without control arm.

CONCLUSIONS

Full-thickness endoluminal closure of large polypectomy sites in humans is feasible for selected difficult polyps. Closure should be performed with concurrent laparoscopic guidance to maximize safety. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT00553436.).

Evaluation of endoscopy in localizing transgastric access for natural orifice transluminal endoscopic surgery in humans

BACKGROUND

To date, transgastric access in humans for natural orifice transluminal endoscopic surgery (NOTES) has been poorly evaluated.

OBJECTIVE

To compare endoscopic visualization of the transgastric access point with the laparoscopically defined ideal entrance to the peritoneal cavity.

DESIGN

Prospective pilot study in humans.

SETTING

Single tertiary-care center.

PATIENTS

This study involved 31 patients referred for laparoscopic cholecystectomy.

INTERVENTION

Access points were marked by endoscopy alone, endoscopy combined with diaphanoscopy, and endoscopy after pneumoperitoneum. Points were correlated with a laparoscopically visualized, previously defined ideal access area.

MAIN OUTCOME MEASUREMENTS

To choose the appropriate access point within the laparoscopically defined ideal access area to the peritoneal cavity away from major vessels and adjacent organs, by using endoscopy and to establish landmarks for the endoscopist, look for a learning curve, and identify potential problems.

RESULTS

The percentage of access points within the laparoscopically defined ideal area was 35.5% with endoscopy alone, 13.8% using the diaphanoscopy method, and 45.2% after transcutaneous pneumoperitoneum. A safe access point (> or = 3 cm from major gastric vessels) could be achieved with the 3 techniques in 83.9%, 65.5%, and 87.1% of patients, respectively. A positive learning curve for endoscopic localization was identified before (P = .008) and after (P = .014) pneumoperitoneum. Virtual complications were greater in obese patients.

LIMITATIONS

This was a small pilot study with hypothetical complications and problems, because actual transgastric access was not performed. The criteria for an ideal access area were very strict.

CONCLUSION

Endoscopy, especially with the use of pneumoperitoneum, can reliably locate a safe transgastric entrance point. However, the endoscopically chosen site correlates poorly with the ideal laparoscopically determined site for transgastric access.

Early healing of transcolonic and transgastric natural orifice transluminal endoscopic surgery access sites

BACKGROUND

Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a developing, minimally invasive surgical approach whose potential benefits are being investigated. Little is known about secure access site closure and early healing kinetics of transvisceral access.

STUDY DESIGN

Transvisceral access incisions were created in the colon (C-NOTES, n = 8) and stomach (G-NOTES, n = 8) for peritoneal exploration. Incisions were closed primarily with endoloops, endoclips, or t-tags. Macroscopic and histologic analyses performed on postoperative day 7 assessed gross appearance, granulation tissue, inflammation, ulceration, and complications.

RESULTS

Macroscopically, incisions appeared closed without intraperitoneal spillage. Incisions closed by endoloop and t-tags showed intense granulation tissue fill of defect despite partial (G-NOTES, n = 3) and transmural ulceration (C-NOTES, n = 8; G-NOTES, n = 3). Of the 30 t-tags applied, 40% broke or deployed into the peritoneal cavity. Endoclip closures (C-NOTES, n = 1; G-NOTES, n = 1) did not show histologic mucosal continuity. Healing complications included transmural necrosis (C-NOTES, n = 1; G-NOTES, n = 1), foreign body material (C-NOTES, n = 3; G-NOTES, n = 2), and microabscesses (G-NOTES, n = 1).

CONCLUSIONS

This study provides a reproducible model to assess noninvasive repair of planned visceral perforations. Of investigated technologies, endoloop closure was favored for transcolonic incisions, and t-tags with omental patch for transgastric incisions, although these have significant limitations. Endoclips were inadequate for primary closure, but may be useful as an adjunctive closure modality. Additional studies are needed to examine visceral repair at later time points, as they will help determine the quality and kinetics of repair of a variety of incision closure strategies. This study demonstrates the need for improved technologies to more reliably close visceral transluminal defects.

Gastric transmural pressure measurements in vivo: implications for natural orifice transluminal endoscopic surgery (NOTES)

BACKGROUND

The success of natural orifice surgery depends on a reliable, secure closure of the opening in the gut. Forces that might be exerted on the gastric wall to disrupt closure have not been measured in humans or animals.

OBJECTIVE

To determine how transmural gastric pressure gradients vary under different experimental conditions.

DESIGN

In vivo porcine model.

SETTING

Animal laboratory.

PATIENTS

Eleven laboratory pigs.

INTERVENTIONS

Pressure transducers were placed in the abdomen and stomachs of the test animals. Simultaneous pressure measurements were obtained to determine the stresses applied to the gastric wall during various maneuvers.

MAIN OUTCOME MEASUREMENTS

Continuous intra-abdominal and intragastric pressures in vivo. Transgastric pressure gradients (DeltaP) were computed in real time by subtracting gastric pressure from abdominal pressure.

RESULTS

In all cases, the measured gastric pressures were nearly identical to those measured in the abdominal cavity because the stomach is entirely contained within the abdomen. The transmural gastric pressure gradients were near zero during a variety of experimental conditions.

LIMITATION

Anesthetized animal model, not engaged in usual activities. Relatively low pressures generated during a cough sequence and a Valsalva maneuver compared with reported values in the literature.

CONCLUSION

Estimates of gastric pressures that must be tolerated by gastric closure devices after natural orifice transluminal endoscopic surgery procedures have been greatly overestimated. Absolute gastric pressure is counteracted by external (intra-abdominal) pressure such that the net transmural gastric pressure gradient remains near zero under a variety of conditions.

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

BACKGROUND

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

METHODS

In this study, 14 domestic farm swine underwent peroral transgastric peritoneoscopy. Under direct endoscopic visualization, a submucosal tunnel was created by dissecting between the mucosal and muscular layers of the stomach. Each tunnel was created with one of four intraabdominal locations (right upper quadrant, left upper quadrant, lesser sac, and pelvis) as the final target for in-line endoscope positioning. Once peritoneal access had been achieved, in-line positioning was assessed and peritoneoscopy was performed. The submucosal tunnels were closed with endoscopically placed clips. The animals were killed 2 weeks after the procedure, and necropsy was performed.

RESULTS

Submucosal tunnels were successfully directed at predetermined intraabdominal targets in 12 of the 14 animals. The mean dissection time required to create the tunnel was 51 +/- 32 min. All the transgastric tunnels were successfully closed with endoscopically placed clips (mean, 3.2 +/- 1.1), and at necropsy showed no evidence of gastrotomy leak in any of the animals. One animal experienced a duodenal perforation unrelated to the transgastric tunneling and was killed on postoperative day 2. The remaining animals recovered and gained weight (mean, 5.5 +/- 1.2 kg) in the 2-week survival period.

CONCLUSIONS

Directed submucosal dissection is technically feasible in a porcine model and permits in-line endoscope positioning with predetermined abdominal target locations. The STAT approach provides safe peritoneal access, allows for a simple reliable endoclip closure, and has an excellent short-term survival rate. This method of achieving transgastric access may be an enabling technique for future NOTES procedures.

In vivo assessment of gastrotomy closure with over-the-scope clips in an experimental model for varicocelectomy (with video)

BACKGROUND

Gastrotomy closure remains the major limiting factor for human translation of transgastric surgery; the over-the-scope clip (OTSC) system was proposed as a possibility for this purpose. Transgastric access is good for a pelvic approach, making varicocelectomy a possible indication for natural orifice transluminal endoscopic surgery (NOTES).

OBJECTIVE

To evaluate the reliability of the OTSC system in vivo after transgastric testicular vessel ligation (varicocelectomy model).

DESIGN

There were 3 experimental groups (5 animals in each): groups 1 and 3, gastrotomy dilation up to 18 mm, surgery was performed with a double-channel endoscope; group 2, gastrotomy dilation up to 13 mm, surgery was performed with a single-channel endoscope.

SETTING

Surgical Sciences Research Domain, Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.

INTERVENTIONS

Bilateral testicular vessel ligation by transgastric access. Gastrotomy closed with the largest version of OTSC system (12 mm): a single clip in groups 1 and 2, and 2 clips in group 3. Animals were monitored for 2 weeks, killed, and submitted for necropsy.

MAIN OUTCOME MEASUREMENTS

Adequacy of closure and healing after the use of the OTSC system. Statistical analysis.

RESULTS

Vessel ligation was easily achieved in all groups. Although differences in the complication rate did not reach statistical significance (P = .099), there was a clear tendency for a better prognosis in groups 2 and 3 than group 1. In fact, only 2 animals from group 1 had complications related to incomplete gastrotomy closure.

LIMITATIONS

Small number of animals per group; nonrandomized study.

CONCLUSIONS

The OTSC system was shown to be easy and efficient for gastrotomy closure in a survival experimental model of varicocelectomy, when correctly matching the gastrotomy size with the clip size and/or number.

Loop-anchor purse-string versus endoscopic clips for gastric closure: a natural orifice transluminal endoscopic surgery comparison study using burst pressures

BACKGROUND

The success of natural orifice surgery depends on a reliable, secure closure of the opening in the gut. Few tests of the integrity of these closures have been published.

OBJECTIVE

To determine whether a gastrotomy can be closed safely and effectively from within the stomach by using looped T-anchors-a novel, endoscopically placed device.

DESIGN

Head-to-head comparison trial of 2 closure methods in 9 explanted porcine stomachs.

SETTING

Animal laboratory.

INTERVENTION

Paired gastrotomies were made in porcine explants. One was closed by using endoscopic clips, and the other was closed by using modified T-anchors in a purse-string fashion.

MAIN OUTCOME MEASUREMENTS

Gastric transmural pressure gradients at bursting of these closures were measured while the explanted stomachs were inflated with a high-pressure insufflator.

RESULTS

The mean burst pressure of the looped T-anchors was 27.3 mm Hg, whereas that of the clip closures was 14 mm Hg. By using 10 mm Hg as a threshold for a "secure" closure, 7 of 9 clip closures failed to meet the threshold value, whereas all 9 of the T-anchor closures met or exceeded the threshold value (P = .0023, 2-tailed Fisher exact test).

LIMITATION

Nonsurvival study.

CONCLUSION

Looped T-anchors provide a secure gastric closure for natural orifice surgery and are superior to endoscopic clips for this purpose.

NOTES: new dimension of minimally invasive surgery

Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery. NOTES eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. Since the first NOTES was reported by Kalloo et al. in 2004, significant achievements in the laboratory have occurred. Clinical use in humans has been limited, but several cases and one small clinical trial were published recently. As a further technical revolution in minimally invasive surgery, NOTES has the promising potential to be safer, less invasive, provide better cosmesis and possibly be more cost-effective. The purpose of the present article was to review the development and current status of NOTES and highlight important advances associated with this innovative approach.

Natural orifice translumenal endoscopic surgery 2009: what is the future for the gastroenterologist?

PURPOSE OF REVIEW

In order to predict whether the gastroenterologist will have a role in the rapidly developing field of natural orifice translumenal endoscopic surgery (NOTES), it is helpful to examine the new developments in this field. Our goal in this review is to examine the recent developments in the field and study the gastroenterologists' role to best make this prediction.

RECENT FINDINGS

Perhaps the most significant development in the field of NOTES has been the favorable patient and physician preferences for NOTES. There is evidence that patients would prefer NOTES cholecystectomy to laparoscopic cholecystectomy. The most common reason for this choice appears to be the lack of pain and visible scar. Another very significant development has been the reality of human NOTES procedures. Multiple centers have reported human NOTES procedures, including transgastric appendectomies, transgastric liver biopsies, transgastric tubal ligation and transvaginal cholecystectomy without major complications. Gastroenterologists' expertise with flexible endoscope was critical in the above cases. Recently, a few publications have also shown how gastroenterologists with expertise in endosonography can have a role in affirming safe access.

SUMMARY

Although no one can predict with certainty where the field of NOTES will be in 1 year, it seems likely that gastroenterologist involvement will be necessary and advancements in this field will be applicable and diffuse into our daily practice.

Endoluminal fundoplication – the Hill procedure

Endoluminal operations for reflux are currently limited by the inability to visualise and manipulate structures outside the wall of the gut. This may be possible using endoscopic ultrasound (EUS). The aim of this study was to define EUS-anatomy of structures outside the gut which influence reflux; to place stitches in the median arcuate ligament (MAL); to perform posterior gastropexy (Hill procedure) and test the feasibility of crural repair under EUS control in pigs. In survival experiments in 14 pigs, using linear array echo-endoscopes the MAL and part of the right crus were identified and punctured with a needle, which served as a carrier for a tag and thread. These were anchored into the muscle. An endoscopic sewing device was used allowing stitches to be placed through a 2.8 mm accessory channel to any predetermined depth. New methods allowed knot-tying and thread-cutting through the 2.8 mm channel of the echo-endoscope. Stitches were placed through the gastric wall into the MAL and one just beyond the wall of the lower esophageal sphincter (LES). They were tied together and locked against the gastric wall. Preoperative manometry showed a median LES pressure of 11 mm/Hg and 21 mm/Hg after stitch placement (p = 0.0028). The length of the LES increased from median 2.8 cm pre-procedure to 3.5 cm post-procedure. At post mortem, the force to pull the tags out of the MAL was 2.8 kg median. This study shows that transgastric gastro-esophageal reflux surgery using stitching under EUS control can significantly increase the lower oesophageal sphincter pressure in pigs.

Development of advanced endoscopes for Natural Orifice Transluminal Endoscopic Surgery (NOTES)

Natural orifice transluminal endoscopic surgery (NOTES) is a hybrid procedure which uses flexible endoscopic technology to perform laparoscopic surgical procedures within the abdominal cavity. Initial reports of animal studies describe the use of standard endoluminal endoscopes to accomplish intra-abdominal surgeries. Current flexible scopes suffer from several deficiencies which make them unlikely to be able to be used for large scale human NOTES experiences. This review analyzes the deficiencies of current endoscopes, discusses the requirements of the ideal NOTES endoscope and reviews some of the possible "endoscopes of the future" that are being developed for the next generation of surgery. Discussion focuses on the "R" scope (Olympus, Tokyo, Japan) and the Transport and Cobra scopes (USGI Medical, San Capistrano, CA).