Transgastric gastropexy and hiatal hernia repair for GERD under EUS control: a porcine model

The role of therapeutic endoscopic ultrasound now and for the future

Therapeutic endoscopic ultrasound (EUS) became possible after the advent of the linear echoendoscope and the EUS guided fine needle aspiration. Over the past two decades, the indications for therapeutic EUS have expanded and evidence regarding its utility has been steadily accumulating. Randomized studies have shown EUS to be effective for cancer pain relief (celiac plexus neurolysis), pancreatic fluid collection drainage, and biliary drainage. Prospective studies have shown EUS-guided biliary drainage to be safe and effective in patients with failed ERCP. There is evidence to suggest that EUS is effective for pancreatic duct drainage, gallbladder drainage, and drainage of pelvic collections. EUS may also be useful for targeted cancer treatment via brachytherapy, radiofrequency ablation, or injection therapy. Therapeutic EUS is likely to play an increasingly important role in endoscopic therapy of gastrointestinal diseases in the near future.

Efficacy of endoluminal gastroplication in Japanese patients with proton pump inhibitor-resistant, non-erosive esophagitis

AIM: To evaluate the efficacy, safety, and long-term outcomes of endoluminal gastroplication (ELGP) in patients with proton pump inhibitor (PPI)-resistant, non-erosive reflux disease (NERD).

METHODS: The subjects were NERD patients, diagnosed by upper endoscopy before PPI use, who had symptoms such as heartburn or reflux sensations two or more times a week even after 8 wk of full-dose PPI treatment. Prior to ELGP, while continuing full-dose PPI medication, patients’ symptoms and quality of life (QOL) were assessed using the questionnaire for the diagnosis of reflux disease, the frequency scale for symptoms of gastro-esophageal reflux disease (FSSG), gastrointestinal symptoms rating scale, a 36-item short-form. In addition, 24-h esophageal pH monitoring or 24-h intraesophageal pH/impedance (MII-pH) monitoring was performed. The Bard EndoCinch^TM was used for ELGP, and 2 or 3 plications were made. After ELGP, all acid reducers were temporarily discontinued, and medication was resumed depending on the development and severity of symptoms. Three mo after ELGP, symptoms, QOL, pH or MII-pH monitoring, number of plications, and PPI medication were evaluated. Further, symptoms, number of plications, and PPI medication were evaluated 12 mo after ELGP to investigate long-term effects.

RESULTS: The mean FSSG score decreased significantly from before ELGP to 3 and 12 mo after ELGP (19.1 ± 10.5 to 10.3 ± 7.4 and 9.3 ± 9.9, P < 0.05, respectively). The total number of plications decreased gradually at 3 and 12 mo after ELGP (2.4 ± 0.8 to 1.2 ± 0.8 and 0.8 ± 1.0, P < 0.05, respectively). The FSSG scores in cases with no remaining plications and in cases with one or more remaining plications were 4.4 and 2.7, respectively, after 3 mo, and 2.0 and 2.8, respectively, after 12 mo, showing no correlation to plication loss. On pH monitoring, there was no difference in the percent time pH < 4 from before ELGP to 3 mo after. Impedance monitoring revealed no changes in the number of reflux episodes or the symptom index for reflux events from before ELGP to 3 mo after, but the symptom sensitivity index decreased significantly 3 mo after ELGP (16.1 ± 12.9 to 3.9 ± 8.3, P < 0.01). At 3 mo after ELGP, 6 patients (31.6%) had reduced their PPI medication by 50% or more, and 11 patients (57.9%) were able to discontinue PPI medication altogether. After 12 mo, 3 patients (16.7%) were able to reduce the amount of PPI medication by 50% or more, and 12 patients (66.7%) were able to discontinue PPI medication altogether. A high percentage of cases with remaining plications had discontinued PPIs medication after 3 mo, but there was no difference after 12 mo. No serious complications were observed in this study.

CONCLUSION: ELGP was safe, resulted in significant improvement in subjective symptoms, and allowed less medication to be used over the long term in patients with PPI-refractory NERD.

Interventional EUS

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of new or emerging endoscopic technologies that have the potential to have an impact on the practice of GI endoscopy. Evidence-based methodology is used by performing a MEDLINE literature search to identify pertinent preclinical and clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but, in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. For this review, the MEDLINE database was searched through August 2009 by using the keywords "interventional endoscopic ultrasound," "EUS," and "interventional endoscopy." Reports on Emerging Technologies are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. These reports are scientific reviews provided solely for educational and informational purposes. Reports on Emerging Technologies are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Natural Orifice Trans-Luminal Endoscopic Surgery in the esophagus

As limited as are the studies regarding peritoneal Natural Orifice Trans-Luminal Endoscopic Surgery, mediastinal transluminal experiments are certainly in their infancy. The authors evaluate the parallel development of minimally invasive thoracic surgery with regard to its counterpart in peritoneal laparoscopy to NOTES. Transesophageal interventions by both endosonographic and direct visualization are examined in the context of minimally invasive surgery and mediastinal NOTES. Techniques of viscerotomy creation, visualization, and closure are examined with particular emphasis on mediastinal structures. The state of current interventions is examined. Finally, current morbidity (including infectious complications) and survival outcomes are examined in those animals that have undergone transesophageal exploration.

[Diagnostic and interventional endoscopy in gastroenterology : from high-resolution chips and procedures for endoscopic resection to NOTES]

In the past 10 years endoscopic diagnostics has benefited from technologies such as big chips, high-definition television (HDTV) and narrow band imaging (NBI). Video capsule endoscopy and double balloon enteroscopy have facilitated visualization of the entire small bowel. A number of studies on mucosal Barrett's and gastric cancers could prove that endoscopic mucosal resection (EMR) is oncologically equivalent to surgical resection when certain criteria are respected. However, EMR is less invasive and carries a substantially lower complication risk and mortality compared to surgery. Endoscopic submucosal dissection (ESD) facilitates en bloc resection with thorough histopathologic evaluation of the specimen, e.g. for mucosal lesions in the stomach and rectum. Endosonography (EUS) guided transgastric necrosectomy using a flexible gastroscope has set a milestone in the treatment of infected pancreatic necroses and has replaced open surgery in many centers. Natural orifice transluminal endoscopic surgery (NOTES) uses natural body openings as minimally invasive access to the abdomen and mediastinum. Interventional GI endoscopists and minimally invasive surgeons have profited from these innovations in micromechanics and microelectronics.

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.

Omentoplasty for gastrotomy closure after natural orifice transluminal endoscopic surgery procedures (with video)

INTRODUCTION

The utility of the greater omentum has not been assessed in transluminal access closure after natural orifice transluminal endoscopic surgery (NOTES) procedures.

OBJECTIVE

Our purpose was to evaluate the feasibility, efficacy, and safety of omentoplasty for gastrotomy closure.

METHODS AND PROCEDURES

Survival experiments in 9 female 40-kg pigs were randomly assigned to 3 groups: group A, endoscopic full-thickness resection (EFTR) for transgastric access and peritoneoscopy without closure; group B, ETFR and peritoneoscopy with omentoplasty (flap of omentum is pulled into the stomach and attached to the gastric mucosa with clips but no clips are used for gastrotomy closure itself); group C, balloon dilation for opening and peritoneoscopy followed by omentoplasty for closure. The animals were observed for 2 weeks and then underwent endoscopy and necropsy with histologic evaluation.

RESULTS

Transgastric opening and peritoneoscopy were achieved in all pigs. In groups B and C, a flap of omentum was easily placed to seal the gastrotomy and then attached to the gastric mucosa with 2 to 5 clips (median 4) in 7 to 20 minutes (median 15 minutes). In group A, peritonitis developed in all animals. In both groups B and C, all animals survived 15 days with no peritonitis and minimal adhesions outside the gastrotomy site. In addition, all achieved complete healing (transmural, n = 4; mucosal ulceration, n = 2) of the gastrotomy site. One animal in group B had an 18-mm abscess in the omental flap.

LIMITATIONS

Animal model, small sample size, lack of appropriate controls for group C.

CONCLUSIONS

Omentoplasty of the gastrotomy site is a technically feasible method to seal balloon-created transgastric access to the peritoneal cavity after NOTES procedures.

Some control-related issues in mini-robotics for endoluminal surgery

This paper introduces some issues related to the development of robotics for endoluminal surgery from control point of view. Endoluminal surgery are incisionless procedures performed through natural orifices within the natural pathways. New devices are then required to achieve these new surgical procedures. Besides the development of new devices, control issues arise in both technological and theoretical aspects. The paper presents some of them and we propose a teleoperation architecture that has already been tested for needle insertion that could be used for teleoperated endoluminal surgery especially for instance for biopsies or anastomoses.

Nephrectomy and natural orifice translumenal endoscopy (NOTES): transvaginal, transgastric, transrectal, and transvesical approaches

This paper outlines recent developments in the field of natural orifice translumenal endosurgery (NOTES) in urology and nephrectomy from the perspective of a flexible endoscopist. The history of transvaginal extraction of kidney specimens using rigid laparoscopic instruments and early studies of transvaginal nephrectomy as a precursor of NOTES are reviewed. Transgastric approaches to nephrectomy using flexible instruments and transvesical hybrid approaches to nephrectomy and other intra-abdominal procedures including cholecystectomy and transvesical lung biopsy are outlined, as are other experimental approaches including transrectal kidney removal. The paper reviews the rationale for a NOTES approach to abdominal surgery and discusses recent human studies. The limitations of NOTES and need for better instrumentation and more studies are stressed.

Endoscopic therapy for GERD: does it have a future?

Approximately 20% of patients with gastroesophageal reflux disease (GERD) have symptoms refractory to long-term proton pump inhibitor (PPI) therapy. Furthermore, PPI therapy is expensive. Fundoplication is considered the gold standard of GERD therapy in terms of normalization of esophageal acid exposure and symptom control; however, this exposes the patient to the risks of surgery and anesthesia. Therefore, an endoscopic approach to treating GERD that obviates the need for PPIs and avoids surgical morbidity is desirable. Several endoscopic methods have been used, including radiofrequency ablation, implantation of foreign substances as bulking agents, and various tissue apposition strategies. The emerging field of GERD endotherapy is promising, but more rigorous, sham-controlled, long-term studies are required to elucidate its exact role in clinical practice. This review discusses the evolution of these concepts, describes specific endoscopic devices that have been developed, and explores the future of endotherapies as viable treatment alternatives for GERD.

Evaluation of a novel access and closure device for NOTES applications: a transcolonic survival study in the porcine model (with video)

BACKGROUND

Natural orifice transluminal endoscopic surgery (NOTES) is a novel, potentially less invasive alternative to laparoscopic surgery. However, the problems of transluminal access and closure represent significant obstacles to its successful introduction in humans.

OBJECTIVE

Our purpose was to evaluate the feasibility and safety of a novel device designed for transluminal access and closure.

DESIGN

Experimental endoscopic study of transcolonic incision and closure with use of a prototype device in a survival porcine model.

SUBJECTS

Four adult female Yorkshire pigs were used in the study.

INTERVENTIONS

While under general anesthesia, the animals were prepped with multiple tap water enemas followed by instillation of an antibiotic suspension and povidone-iodine lavage. At a distance of 15 to 20 cm from the anus, the prototype device deployed a circumscribing purse-string suture around the planned incision site and subsequently used a blade mechanism to create a 2.5-cm linear incision. The peritoneum was then accessed with a standard double-channel enodoscope. The transcolonic incision was then closed by cinching and securing the purse-string suture with a titanium knot by use of a separate hand-activated suture-locking device. All animals were allowed to eat immediately after recovering from general anesthesia.

MAIN OUTCOME MEASUREMENTS

The animals were monitored daily for signs of peritonitis and sepsis and were electively killed on day 14. The peritoneal cavity was examined for peritonitis, and the colonic incision site was examined for wound dehiscence, pericolic abscess formation, and gross adhesions. Tissue samples from both incisional and random peritoneal sites were obtained for histologic examination.

RESULTS

Transcolonic incision and closure were successful in all 4 animals. The device performed in a rapid and reproducible fashion. All animals recovered without septic complications. At necropsy, there was no evidence of peritonitis, abscesses, or wound dehiscence. Salpingocolonic and colovesicular adhesions were noted in 3 of 4 animals. Histologic examination revealed microabscesses at the incision site in all animals.

CONCLUSIONS

The prototype incision and closure device represents a promising solution to the problems of transluminal access for NOTES. The presence of incision-related adhesions and microabscesses signal the need for further refinement in aseptic technique.

EUS-guided NOTES interventions

Entering the peritoneal cavity with the echoendoscope has been avoided because this endoscope is rather rigid and difficult to handle and maneuver in a limited space. Endoscopic ultrasound may be of help, however, to guide natural orifice translumenal endoscopic surgery (NOTES) procedures. This article provides an overview of the potential benefit and the few endoscopic ultrasound-based natural NOTES procedures performed to date.

NOTES--third generation surgery. Vain hopes or the reality of tomorrow?

BACKGROUND

Laparoscopic approach has made many procedures less invasive; however, it seems like this is not enough. The newest challenge for the medical environment is applying the scarless surgery in humans. In this article, we review the origin, current state of art, and future of natural orifice transluminal endoscopic surgery (NOTES). The registered base of research in humans is yet scarce; however, the porcine model experimental studies hold a great promise. In NOTES, peritoneal cavity can be easily achieved, and some procedures are feasible through the natural orifices like digestive tract, vagina, or urinary bladder. If safety and advantages of these approaches will be proven beyond question, NOTES procedures are likely to be adapted in humans after overcoming the critical obstacles, like reliable closure methods, indispensable equipment invention, the multidisciplinary specialists training, etc. The aim of this article was to review available literature to provide current state of art in NOTES surgery.

MATERIALS AND METHODS

Medical databases were searched for animal and human experience with NOTES to give an overview of history, current state of art, and future of this technique.

RESULTS

NOTES is currently the subject of the intensive research. It seems like this is only the matter of time when a transluminal access to the abdominal or even thoracic cavity will become the reality. Moreover, this will enable the management of some diseases in a possibly minimally invasive pattern, nearly painless and leaving no scar at all.

Endolaparoscopic approach in the management of gastroesophageal reflux disease: an experimental study in pigs

INTRODUCTION

Chronic reflux of gastric content to the esophagus causes retrosternal burning, pain, and regurgitation, and results in histopathologic changes that may culminate in adenocarcinoma. Insufficiency of the lower esophageal sphincter and hiatal hernia are the two principal causative factors. In this paper, we present the early results of a new antireflux operation in pigs.

MATERIALS AND METHODS

The status of physiologic reflux was determined in 5 pigs (approximately 40-45 kg) with 24-hour pH monitorization. Under endoscopic guidance, a trocar was inserted into the stomach (similar to the percutaneous endoscopic gastrostomy technique). The endoscope was put into the retroflexed position; a mucomuscular pursestring suture was placed around the endoscope at the cardia and tied. Ten days later, pH monitorization was repeated to evaluate the effectiveness of the method. Late postoperative results have been reevaluated by 24-hour pH monitorization in the sixth month.

RESULTS

The procedure achieved statistically significant improvements in total reflux time, number of reflux periods, number of long reflux periods, the longest reflux period, and the DeMeester score. The preoperative and postoperative DeMeester scores of the individual animals were 179.24-0.94, 11.48-0.98, 68.4-3.74, 132.2-46.49, and 38.72-5.86, respectively. Even though there appeared to be a slight increase in the pH monitorization levels after 6 months, these results did not reach significant degrees, and compared to the physiological reflux, the results were remarkable.

CONCLUSIONS

The results obtained showed considerable decreases in physiologic reflux in all animals. We believe that this endoluminal, laparoendoscopic operation can be used in the treatment of gastroesophageal reflux disease as a minimally invasive method.

Completely transvaginal NOTES cholecystectomy using magnetically anchored instruments

INTRODUCTION

Natural orifice translumenal endoscopic surgery (NOTES) is an evolving field and suitable instruments are lacking. The purpose of this study was to perform transvaginal cholecystectomies using instruments incorporated into a magnetic anchoring and guidance system (MAGS).

METHODS

Non-survival procedures were conducted in pigs (n = 4). Through a vaginotomy created under direct vision, a rigid access port was inserted into the peritoneal cavity and used to maintain a CO(2) pneumoperitoneum. MAGS instruments were deployed through the port and held in place on the peritoneal surface using magnetic coupling via an external handheld magnet which was optionally exchanged for an 18 ga percutaneous threaded needle anchor; instruments included a tissue retractor (a clip-fixated magnet or flexible graspers) and a cautery dissector. A gastroscope was used for visualization.

RESULTS

The first two procedures ended prematurely due to instrumentation shortcomings and inadvertent magnetic coupling between instruments; one case required a laparoscopic rescue. Three new forms of instrumentation were developed: (1) a longer access port (50 cm) which provided easier deployment of instruments and suitable reach, (2) a more robust cauterizer with a longer, more rigid, pneumatically deployed tip with better reach and sufficient torque to allow blunt dissection, and (3) a more versatile tissue retractor with bidirectional dual flexible graspers which provided excellent cephalad fundus retraction and inferiolateral infundibulum retraction. With these modifications, 100% of the cholecystectomy was completed in the third and fourth animals using only a NOTES/MAGS approach. Retrieval of the tissue retractor resulted in a rectal injury in the third animal but further procedural modifications resulted in a successful procedure in the fourth animal with no complications.

CONCLUSIONS

While still under development with more refinements needed, completely transvaginal cholecystectomy using MAGS instruments is feasible. By offering triangulation and rigidity, MAGS may facilitate a NOTES approach while alleviating shortcomings of a flexible platform.

Endoscopic suturing: now and incoming

There is a particular need for inexpensive, simple multipurpose suturing methods that can be used for most applications. Such devices are in advanced stages of development and early clinical use. Complex procedure-specific devices that fix large-volume procedures such as reflux or obesity may well be needed but will need to prove their value in clinical studies.

Endosurgery: what do we need?

A paradigm shift in therapeutic endoscopy occurred with the advent of mucosectomy for the treatment of mucosal neoplasms and suture plication for gastroesophageal reflux disease. The objectives changed from finding simple, easy, and quick alternatives to surgery to reproducing surgical results. A radical version of flexible endoscopy has emerged to meet new goals of full-thickness resections, creation of anastomoses, and lumen reconfiguration. This will require a new generation of endosurgical tools that cut, stitch, and staple with added dimensions of multiaxis orientation and triangulation.

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

Natural orifice transenteric surgery (NOTES) is a new and rapidly evolving concept for intra-abdominal operations that offers the potential for a revolutionary advance in patient care. Conceptually, operations that currently require an open or laparoscopic approach could be performed without incisions in the abdomen, with their concomitant pain and scarring. A recent consensus statement by a joint group of gastrointestinal surgeons and gastroenterologists has identified several technical and technologic hurdles that would need to be overcome before NOTES becomes a clinical reality. One of the most significant requirements identified is the need for a very secure closure of the gastrotomy site that is required for scope passage and specimen removal. Although a rapidly expanding variety of transgastric procedures has been reported, only a few reports address the basic problem of gastrotomy closure. Availability of a safe and simple gastrotomy closure device, however, will be essential for the widespread adoption of the new field of NOTES. Unless new safe and simple devices for endoscopic gastrotomy closure are available and have proven efficacy, NOTES will remain in the hands of a few specialists at centers of excellence because the risk of complications due to insufficient gastrotomy closure will not be acceptable for the surgeon and gastroenterologist in general practice. In this article, we describe three new devices in development or newly on the market that are targeted to advance the safe endoscopic closure of gastrotomy from NOTES.

Endoscopic full-thickness resection: circumferential cutting method

BACKGROUND

Endoscopic full-thickness resection (EFTR) at flexible endoscopy might allow less-invasive removal of more deeply penetrating cancers that have not spread to the serosal surface and more complete histologic examination of the excised tissue.

OBJECTIVE

A method for closure of full-thickness defects in the stomach wall would be valuable for other endosurgical applications.

SETTING

A method that uses an end cap and band-ligation without prior injection of saline solution to perform EFTR gave good results and was safe in pig studies. There is a size limitation of cancers that can be resected en bloc when using this method. The depth of resection was also variable.

DESIGN AND INTERVENTIONS

EFTR was achieved by circumferential cutting with a sphincterotome and a snare. A prototype bidirectional cutter was tested. Sutured closure was accomplished by using a sheathed needle, a metal tag, and a thread at the tip, passed through a 2.8-mm accessory channel. Knot-tying devices secured the sutured defect.

MAIN OUTCOME MEASUREMENTS

EFTR was studied in non-survival (n = 4) and survival (n = 8) experiments in pigs.

RESULTS

Full-thickness specimens were resected from the gastric wall (100%, 12/12), and the defects were closed by using sewing and knot-tying devices (100%, 12/12).

LIMITATIONS

A healing ulcer at the suturing site was evident at follow-up endoscopy in the survival experiments. Bleeding, which was stopped by suturing, occurred in 1 pig (8.3%, 1/12). All pigs survived these experiments without complications (100%, 8/8).

CONCLUSIONS

Circumferential EFTR was feasible and appeared safe in survival experiments. This method might allow larger and deeper resection of tumors in the gastric wall.

Endoscopic transgastric lymphadenectomy by using EUS for selection and guidance

BACKGROUND

EUS-guided fine needle aspiration (EUS-FNA) is a reliable tool for tissue diagnosis of unexplained mediastinal or perigastric lymphadenopathy but may be ineffective in sampling a small malignant focus in it or removing an entire node.

OBJECTIVE

To develop a new EUS-guided endoscopic-transgastric method to approach (sentinel) lymph nodes, including node marking and lymphadenectomy.

DESIGN

Experimental study.

SETTING

Animal experiments at an approved university college.

SUBJECTS

Six pigs had a linear-array EUS examination 1 week after a transgastric procedure. All had reactive perigastric lymph nodes.

INTERVENTIONS

Selected nodes were punctured with a 19-gauge EUS needle. A metal anchor with thread, loaded onto the needle, was placed across the lymph nodes to pull the node toward the stomach. After gastric-wall dissection with a needle knife at the point of emergence of the thread, the nodes were removed by pulling on the thread and the anchor. The gastric incision was closed with an endoscopic suturing system.

MAIN OUTCOME AND MEASUREMENTS

Proof of the feasibility to endoscopically remove paragastric lymph nodes by an EUS-guided transgastric approach.

RESULTS

In all pigs, lymph-node marking with an anchor and thread was possible. Traction exerted on these nodes showed that they could be pulled against the gastric wall for subsequent removal. In 2 of 6 examinations, the entire sequence of the procedure, node tagging, gastric-wall incision, lymphadenectomy, and wall closure was performed. No serious complication occurred.

LIMITATIONS

Animal study throughout, small numbers, no humans to date.

CONCLUSIONS

Transgastric lymphadenectomy with EUS for node selection and capturing seems feasible.

Development of a new access device for transgastric surgery

Flexible endoscope-based endoluminal and transgastric surgery for cholecystectomy, appendectomy, bariatric, and antireflux procedures show promise as a less invasive form of surgery. Current endoscopes and instruments are inadequate to perform such complex surgeries for a variety of reasons: they are too flexible and are insufficient to provide robust grasping and anatomic retraction. The lack of support for a retroflexed endoscope in the peritoneal cavity makes it hard to reach remote structures and makes vigorous retraction of tissues and organs difficult. There is also a need for multiple channels in scopes to allow use of several instruments and to provide traction/countertraction. Finally, secure means of tissue approximation are critical. The aim was to develop and test a new articulating flexible endoscopic system for endoluminal and transgastric endosurgery. A multidisciplinary group of gastrointestinal physicians and surgeons worked with medical device engineers to develop new devices and instruments. Needs assessments and design parameters were developed by consensus. Prototype devices were tested using inanimate models until usable devices were arrived at. The devices were tested in nonsurvival pigs and dogs. The devices were accessed through an incision in the wall of the stomach and manipulated in the peritoneal cavity to accomplish four different tasks: right upper quadrant wedge liver biopsy, right lower quadrant cecal retraction, left lower quadrant running small bowel, and left lower quadrant exposure of esophageal hiatus. In another three pigs, transgastric cholecystectomy was attempted. The positions of the device, camera, and endosurgical instruments, with and without ShapeLock technology, were recorded using laparoscopy and endoscopy and procedure times and success rates were measured. Instrument design parameters and their engineering solutions are described. Flexible multilumen guides which could be locked in position, including a prototype which allowed triangulation, were constructed. Features of the 18-mm devices include multidirectional mid body and/or tip angulation, two 5.5-mm accessory channels allowing the use of large (5-mm) flexible endosurgical instruments, as well as a 4-mm channel for an ultraslim prototype video endoscope (Pentax 4 mm). Using the resulting devices, the four designated transgastric procedures were performed in anesthetized animals. One hundred percent of the transgastric endosurgical procedures were accomplished with the exception of a 50% success for hiatal exposure, a 90% success rate for wedge liver biopsy, and a 33.3% success rate for cholecystectomy. A new endosurgical multilumen device and advanced instrumentation allowed effective transgastric exploration and procedures in the abdominal cavity including retraction of the liver and stomach to allow exposure of the gallbladder, retraction of the cecum, manipulation of the small bowel, and exposure of the esophageal hiatus. This technology may serve as the needed platform for transgastric cholecystectomy, gastric reduction, fundoplication, hiatus hernia repair, or other advanced endosurgical procedures.

Depth of endoscopically placed sutures: an experimental study in a human cadaver model

BACKGROUND

Endoscopic suturing devices offer interesting access for interventional procedures used on the gastrointestinal tract. For the time being, the main indication is endoluminal suturing at the gastroesophageal junction for the management of gastroesophageal reflux disease. There is some evidence that endoluminal endoscopic suturing offers an alternative to the closure of esophageal fistulas and to the fixation of feeding tubes and stents in the near future. A review of the literature found no anatomic data on wall layers stitched by sutures. The aim of this study was to determine the depth of sutures placed endoscopically in the esophagus of a human cadaver model.

METHODS

Altogether, 62 sutures were placed in the esophagi of 10 cadavers (complete exenterative cadaver model) at three different suction levels (0.4, 0.6, and 0.8 bar) using the EndoCinch suturing machine. After preparation of the esophagus from its mediastinal bed, all sutures were fixed in formalin and stained with hematoxylin and eosin for histologic examination.

RESULTS

No sutures were placed in the mucosa alone. As observed, 1.6% were placed in the submucosa, 4.8% in the circular muscularis propria, and 56.5% in the longitudinal muscularis propria, with 37% placed transmurally. At a suction level of 0.4 bar (0.6, 0.8 bar), 0% (0%, 1.6%) were placed in the submucosa, 3.2% (0%, 1.6%) in the circular muscularis propria, and 11% (25.8%, 12.9%) in the longitudinal muscularis propria, with 12.9% (6.5%, 17.7%) placed transmurally.

CONCLUSIONS

This study reports, for the first time, a systematic examination of the depth of sutures placed endoscopically in the esophagus. Most of the sutures were found in the muscular wall of the esophagus at a suction level of 0.6 bar. Also, transmural placements were seen. Reduction of suction pressure may lead to a decrease in transmural sutures.

Present and future of endoscopic ultrasonography

Endoscopic ultrasonography and endoscopic ultrasonography-guided fine needle aspiration are well-established techniques, encompassing a variety of diagnostic and therapeutic applications. Along with traditional indications that constitute everyday clinical practice in all endoscopic ultrasonography centres, new indications are emerging that resemble the continuing research carried on in this field. Some of these are innovative applications, developed by highly experienced endosonographers and with a putative role for clinical practice in the near future. Others are merely experimental applications, carried out on in animal models or in highly selected groups of patients, opening up new fascinating areas of research but not for imminent introduction in clinical practice. The purpose of this review, after summarising the present indications of endoscopic ultrasonography, is to focus on the future applications and try to establish their possible advent, either in the near or in the far future.

Future therapeutic indications for endoscopic ultrasound

Attempts to perform therapy guided by endoscopic ultrasound (EUS) are rare. Some new indications for interventional and therapeutic endoscopic procedures performed under EUS control have been developed in areas that have been purely surgical for many years. Indications, procedures, and related tools for EUS-guided endosurgery are described, all of which are experimental but may open a new corridor for endoscopists to enter a variety of transluminal procedures in real time without soiling the peritoneal or mediastinal cavity.

Relationship of Helicobacter pylori related gastritis, gut hormones and gastroesophageal reflux disease

AIM: To evaluate the relationship of H. pylori infection, H. pylori -related gastritis, serum gastrin and motilin levels and esophageal lesions in gastroesophageal reflux disease (GERD).

METHODS: All 53 GERD patients were divided into non-erosive reflux disease (NERD group, 32 cases) and reflux esophagitis (RE group, 21 cases ) by endoscopy. The degrees of gastritis in antrum and body as well as esophagitis were evaluated by pathological examinations. Fasting serum gastrin and motilin concentrations were determined by radioimmunoassay. H. pyloriwas examined by serum H. pylori-antibody, Warthin-Starry stain, urease-dependent test (rapid urease test or ¹⁴C-breath test).H. pylori infection was affirmed when at least two of three tests were positive. 20 normal persons were as controls. In NERD group, 18 were H. pylori positive and 14 were negative. In RE group 12 were H. pylori positive and 9 were negative. According to the classification of esophagitis, 11 were ClassⅠ, 7 ClassⅡ and 3 Class Ⅲ. There were 30 H. pylori (+) and 23 H. pylori (-) in 53 GERD patients.

RESULTS: As compared with healthy controls, fasting serum motilin levels in RE group were significantly lower (360±126 vs 440±110 mg/L, ^aP < 0.05) and those in NERD group were similar (P > 0.05). No differences in gastrin levels were found between NERD or RE group and controls (both P > 0.05). The serum gastrin levels in H. pylori (+) GERD were significantly higher than controls (35.8±11.6 vs 28.5±10.6 mg/L, ^bP < 0.05). In H. pylori (+) GERD patients, gastritis grades in the antrum and gastric body were significantly higher than that in H. pylori (-) patients (χ² = 32.97, χ² = 15.67, both P < 0.005). The esophagitis grades were similar in H. pylori (+) and H. pylori (-) GERD (χ² = 0.82, P > 0.05). The gastritis grades were not associated with the esophagitis degrees, but with H. pylori infection.

CONCLUSION: Motilin is involved in the pathogenesis of RE. H. pylori can lead to hypergastrinemia and gastritis in the antrum and gastric body.