Widespread EMR: a new technique for removal of large areas of mucosa

Endoluminal Instrumentation Is Changing Gastrointestinal Surgery

Advances in endoluminal instrumentation and technology are enabling endoscopists to perform increasingly sophisticated procedures. Indications for these procedures are likely to expand as outcomes studies show they are efficacious and cost-effective. This article highlights several recent advances in endoluminal suturing, dissecting, and ligating and discusses the impact of these advances on the practice of gastrointestinal surgery. Endoluminal suturing offers select patients with gastroesophageal reflux disease a safe and effective alternative to laparoscopic surgery. Devices designed for endoluminal hemostasis and endoscopic mucosal resection can be used effectively for a broader range of applications and are already being used to perform transluminal surgery in animal models; human trials are forthcoming. Gastrointestinal surgeons should support efforts to critically evaluate endoluminal techniques because they have an opportunity to improve care. Surgical residents planning careers in gastrointestinal surgery need to understand endoscopic techniques and consider their training opportunities.

The Evolution of "New Notes," Origins, and Future Directions

The transformation of the submucosa into a working space provided a paradigm shift for endolumenal endoscopic intervention. The submucosal space can provide an undermining access to the removal of overlying mucosal disease. This space can also provide a protective mucosal barrier accommodating interventions into the deep layers of the gut wall and body cavities, such as the abdomen and mediastinum.

Peroral endoscopic myotomy (POEM) for esophageal primary motility disorders: analysis of 100 consecutive patients

INTRODUCTION

Peroral endoscopic myotomy (POEM) is a flexible endoscopic approach to the lower esophageal sphincter (LES) providing access for a myotomy to relieve dysphagia. The technique has been adopted worldwide due to reports of excellent short-term clinical outcomes. We report on a consecutive patient cohort with clinical and objective outcomes representing the establishment of a POEM program within a busy esophageal surgical practice.

METHODS

Comprehensive data was collected prospectively on all patients undergoing POEM from October 2010 to November 2013 at a single institution. Patients were classified based on high-resolution manometry (HRM). Operative data and immediate outcomes were reviewed. Symptom scores, HRM, and timed barium swallow (TBS) were performed prior to the procedure. Patients were asked to undergo routine postoperative testing 6-12 months after surgery with the addition of standard 24-h pH to the preoperative protocol. Morbidity was defined as requiring additional procedures or prolonged hospital stay >2 days.

RESULTS

One hundred POEM patients were included in the final analysis. The mean age was 58 years (18-83 years). Primary presenting symptoms included dysphagia 81, chest pain 10, and regurgitation 9. The mean follow-up was 16 months. HRM diagnoses were 75 achalasia (30 type I, 43 type II, 2 type III), 12 nutcracker esophagus, 5 diffuse esophageal spasm (DES), and 8 isolated hypertensive non-relaxing LES. The mean operative time was 128 min. The median hospital length of stay (LOS) was 1 day. The overall morbidity was 6%; all were treated endoscopically or with conservative management without further sequelae (three had intra-tunnel leak diagnosed on routine esophagram and one developed a postoperative intra-tunnel hemorrhage, one developed Ogilvie's, and one required prolonged intubation for CO2 retention). The average LES resting/residual pressure significantly decreased (44.3/22.2 to 19.6/11.7 in millimeters of mercury). Esophageal emptying improved from 40 to 90% on TBS with 93% patients demonstrating >90% emptying at 1 min. Of the achalasia patients, 36% (17/47) showed some return of normal peristalsis (≥70% peristalsis) on post-op HRM. Abnormal acid exposure was present on postoperative testing in 38% (26/68). Of these, 14 were asymptomatic. No reflux patient required additional antireflux procedure. Eckardt scores decreased from 6 to 1. Dysphagia was improved or eradicated in 97% with a complete resolution accomplished in 89%. Complete dysphagia relief was better for achalasia patients (46/47 patients; 97.8%) vs. non-achalasia patients (17/24; 70.8%). Of those with preoperative chest pain, 91.5% reported complete relief. Four patients have refractory dysphagia. Two non-achalasia patients underwent subsequent laparoscopic Heller myotomy and two are improved following serial endoscopic dilatations.

CONCLUSION

This study represents the largest POEM series to date that includes objective data. Despite reflux in one/three of patients, POEM provides excellent relief of dysphagia (97%) and chest pain (91.5%) for patients with esophageal spastic disorders with acceptable procedural morbidity.

Investigating deeper: muscularis propria to natural orifice transluminal endoscopic surgery

Submucosal endoscopy with a mucosal flap (SEMF) safety valve technique is a global concept in which the submucosa is a free working space for endoscopic interventions. A purposefully created intramural space provides an endoscopic access route to the deeper layers and into the extraluminal cavities. The mucosa overlying the intramural space is protective, reducing contamination during natural orifice transluminal endoscopic surgery (NOTES) procedures and providing a sealant flap to repair the entry point and the submucosal space. In addition to NOTES, SEMF enables endoscopic achalasia myotomy, histologic analysis of the muscularis propria, and submucosal tumor removal.

Water-jet dissector for endoscopic submucosal dissection in an animal study: outcomes of the continuous and pulsed modes

BACKGROUND

Endoscopic submucosal dissection (ESD) allows en bloc resection of early neoplastic lesions of gastrointestinal tract. Lesions are lifted by submucosal fluid injection before circumferential incision and dissection. High-pressure fluid injection using water jet (WJ) technology is already used for lifting and dissection in surgery. The study was designed to assess WJ for ESD submucosal lifting and dissection.

METHODS

An experimental, randomized comparative, "in vivo" nonsurvival animal study on 12 pigs was designed. Stomach mucosal areas were delineated and resected using three ESD techniques: technique A-syringe injection and IT knife dissection; technique B-WJ continuous injection and IT knife dissection; technique C-WJ injection and WJ pulsed dissection. Injection and dissection speeds and complications rates were assessed.

RESULTS

Water jet continuous injection is faster than syringe injection (B faster than A, p = 0.001 and B nonsignificantly faster than C, p = 0.06). IT knife dissection is significantly faster after WJ continuous injection (B faster than A, p = 0.003). WJ pulsed dissection is significantly slower than IT knife dissection (C slower than A and B, both p < 0.001). The overall procedure speed was significantly higher and the immediate bleedings rate was significantly lower for technique B than A and C (overall procedure speed p = 0.001, immediate bleedings p = 0.032 and 0.038 respectively). There were no perforations with any technique.

CONCLUSIONS

Water jet fluid continuous injection speeds up ESD, whereas pulsed WJ dissection does not.

Long-term outcomes of an endoscopic myotomy for achalasia: the POEM procedure

BACKGROUND

Esophageal achalasia is most commonly treated with laparoscopic myotomy or endoscopic dilation. Per-oral endoscopic myotomy (POEM), an incisionless selective myotomy, has been described as a less invasive surgical treatment. This study presents 6-month physiological and symptomatic outcomes after POEM for achalasia.

METHODS

Data on single-institution POEMs were collected prospectively. Pre- and postoperative symptoms were quantified with Eckardt scores. Objective testing (manometry, endoscopy, timed-barium swallow) was performed preoperatively and 6 months postoperatively. At 6 months, gastroesophageal reflux was evaluated by 24-hour pH testing. Pre-/postmyotomy data were compared using paired nonparametric statistics.

RESULTS

Eighteen achalasia patients underwent POEMs between October 2010 and October 2011. The mean age was 59 ± 20 years and mean body mass index was 26 ± 5 kg/m. Six patients had prior dilations or Botox injections. Myotomy length was 9 cm (7-12 cm), and the median operating time was 135 minutes (90-260). There were 3 intraoperative complications: 2 gastric mucosotomies and 1 full-thickness esophagotomy, all repaired endoscopically with no sequelae. The median hospital stay was 1 day and median return to normal activity was 3 days (3-9 days). All patients had relief of dysphagia [dysphagia score ≤ 1 ("rare")]. Only 2 patients had Eckardt scores greater than 1, due to persistent noncardiac chest pain. At a mean follow-up of 11.4 months, dysphagia relief persisted for all patients. Postoperative manometry and timed barium swallows showed significant improvements in lower esophageal relaxation characteristics and esophageal emptying, respectively. Objective evidence of gastroesophageal reflux was seen in 46% patients postoperatively.

CONCLUSIONS

POEM is safe and effective. All patients had dysphagia relief, 83% having relief of noncardiac chest pain. There is significant though mild gastroesophageal reflux postoperatively in 46% of patients in 6-month pH studies. The lower esophageal sphincter shows normalized pressures and relaxation.

Advantages of endoscopic submucosal dissection versus endoscopic oblique aspiration mucosectomy for superficial esophageal tumors

BACKGROUND AND AIM

In the treatment of superficial esophageal tumors (SET), en bloc histologically-complete resection reduces the risk of local recurrence. Endoscopic oblique aspiration mucosectomy (EOAM) and endoscopic submucosal dissection (ESD) have been applied to resect SET. The aim of this study was to retrospectively determine whether ESD is more advantageous than EOAM for SET.

METHODS

In the present study, there was a total of 122 patients in whom 162 SET were resected endoscopically at Hiroshima University Hospital. EOAM (83 lesions/63 patients) or ESD (79 lesions/59 patients) was performed. En bloc histologically-complete resection rates, operation time, complications, and the local recurrence rate were studied.

RESULTS

In SET > 20 mm, the en bloc histologically-complete resection rate was significantly higher with ESD than with EOAM (94% vs 42%, P < 0.001). In SET of 16-20 mm, the rate tended to be higher with ESD than with EOAM (100% vs 81%, P = 0.08). In SET < 15 mm, the rates did not differ significantly between groups. The average operation time was significantly longer for ESD than for EOAM, regardless of tumor size (49.7 ± 33.0 min vs 19.1 ± 6.1 min, P < 0.001). Complication rates did not differ significantly between groups. The local recurrence rate was significantly lower with ESD than with EOAM (0%, mean observation period: 18.9 months vs 9%, mean observation period: 30.7 months, P = 0.03).

CONCLUSION

Although increased operation time with ESD remains problematic, SET > 15 mm should be treated with ESD to reduce local recurrence. In lesions ≤ 15 mm, EOAM might be preferable, especially in high-risk patients.

Combination of water-jet dissection and needle-knife as a hybrid knife simplifies endoscopic submucosal dissection

BACKGROUND

The safety and efficacy of endoscopic submucosal dissection (ESD) is very dependent on an effective injection beneath the submucosal lamina and on a controlled cutting technique. After our study group demonstrated the efficacy of the HydroJet in needleless submucosal injections under various physical conditions to create a submucosal fluid cushion (Selective tissue elevation by pressure = STEP technique), the next step was to develop a new instrument to combine the capabilities of an IT-Knife with a high-pressure water-jet in a single instrument. In this experimental study, we compared this new instrument with a standard ESD technique.

METHODS

Twelve gastric ESD were performed in six pigs under endotracheal anesthesia. Square areas measuring 4-cm x 4-cm were marked out on the anterior and posterior wall in the corpus-antrum transition region. The HybridKnife was used as an standard needle knife with insulated tip (i.e., the submucosal injection was performed with an injection needle and only the radiofrequency (RF) part of the HybridKnife was used for cutting (conventional technique)) or the HybridKnife was used in all the individual stages of the ESD, making use of the HybridKnife's combined functions (HybridKnife technique). The size of the resected specimens, the operating time, the frequency with which instruments were changed, the number of bleeding episodes, and the number of injuries to the gastric wall together with the subjective overall assessment of the intervention by the operating physician were recorded.

RESULTS

The resected specimens were the same size, with average sizes of 16.96 cm(2) and 15.85 cm(2) resp (p = 0.8125). Bleeding episodes have been less frequent in the HybridKnife group (2.83 vs. 3.5; p = 0.5625). The standard knife caused more injuries to the lamina muscularis propria (0.17 vs. 1.33; p = 0.0313). The operating times had a tendency to be shorter with the HybridKnife technique (47.18 vs. 58.32 minute; p = 0.0313).

DISCUSSION

The combination of a needle-knife with high-pressure water-jet dissection improved the results of endoscopic submucosal dissection in this experimental setting. Because the frequency of complications is still high, further improvements to the instrument are necessary.

Submucosal injection solution for gastrointestinal tract endoscopic mucosal resection and endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have provided new alternatives for minimally invasive treatment of gastrointestinal adenomas and early-stage cancers that involve a minimum risk of lymph-node metastasis. The use of submucosal injections is essential to the success of these endoscopic resection techniques. The “ideal” submucosal injection solution should provide a sufficiently high submucosal fluid cushion for safe and effective EMRs and ESDs while also preserving lesion tissue for accurate histopathological assessment. In the past, normal saline (NS) solution was commonly used for this purpose, but it is difficult to achieve the proper submucosal elevation and maintain the desired height with NS. Therefore, other safe and effective facilitative submucosal injection solutions have been developed that also take into account relevant cost-benefit considerations. This review examines recent advances in the development of effective submucosal injection solutions for use during endoscopic resections.

En bloc esophageal mucosectomy for concentric circumferential mucosal resection (with video)

BACKGROUND

With conventional EMR, specimens are fragmented, metaplasia may be left behind, and invasive lesions could be missed because of incomplete sampling. Concentric subtotal esophageal mucosectomy would address these limitations.

OBJECTIVE

To examine en bloc esophageal mucosectomy (EEM).

DESIGN

A prospective case series.

SETTING

An academic hospital.

SUBJECTS

Nine swine.

INTERVENTIONS

Conventional EMR was performed in the proximal esophagus. The submucosal space was entered, and the distal two thirds of the esophageal mucosa was freed with blunt dissection. A snare was threaded over the column of mucosa to the gastroesophageal junction. The column was resected, and the mucosa was retrieved.

MAIN OUTCOME AND MEASUREMENTS

Clinical examination, follow-up endoscopy, necropsy, and gross and histopathologic examination.

RESULTS

EEM permitted subtotal esophageal mucosectomy in 9 of 9 swine (tissue specimens removed ranged 9-15 cm in length). The mean procedure duration was 110 minutes. In the survival series, 4 of 4 swine thrived after surgery, for 9 to 13 days. At 9 days, there was no evidence of a perforation, stricture, or leak. At 13 days, 2 swine had a mild proximal stricture, which was easily traversed with a 9.8-mm gastroscope. On necropsy, the mediastinal and thoracic cavities were unremarkable in 3 of 4 swine. One swine was found to have a contained abscess containing cellulose, presumably secondary to ingestion of wood-chip bedding material postoperatively. Reepithelialization was present on histologic examination.

LIMITATIONS

An animal study.

CONCLUSIONS

EEM is feasible and enabled concentric subtotal esophageal mucosal resection. The technique could completely and circumferentially excise intramucosal lesions. Longer follow-up and larger studies are needed to evaluate infection, stricture, and safety.

Submucosal cushioning with water jet before endoscopic mucosal resection : Which fluids are effective?

BACKGROUND

Several new techniques have recently been described that allow the endoscopic mucosal resection even of broad-based flat lesions in the gastrointestinal tract. The technique recently described by us of using a water jet dissector (Helix HydroJet) for a selective deposition of liquid in the submucosal lamina has now been combined with different substances, and their effects have been compared.

MATERIAL AND METHODS

Gastroscopies were carried out in 8 pigs under intubation anesthesia, and 2 submucosal cushions each were created in the stomach using one out of 4 test substances (gelatin, glucose 50, hydroxyethyl starch [HES] 10%, dextran 40), as well as one cushion of isotonic saline solution placed in each area via the Helix HydroJet). The height of the submucosal cushions was intermittently measured over a period of 40 or 20 min, respectively, by miniprobe endosonography. In 7 of the animals the stomach was subsequently subjected to mucosal resection. The specimens and the gastric wall were histologically assessed to evaluate the localization of the liquid cushion and the effect on adjacent layers of the gastric wall.

RESULTS

All test substances produced strictly selective liquid cushions in the submucosa. With HES 10% and dextran the maximum height of the cushions initially increased and then decreased during the further course to an average of 90% of the initial height within 40 min. Isotonic saline solution showed the most rapid decrease in height (72% after 20 min). The histological assessment confirmed the selective nature of the liquid deposit in the submucosa.

DISCUSSION

Plasma expanders produced cushions that initially increased in height but then remained constant for a longer period than cushions produced using glucose 50, gelatin, or isotonic saline solution. The combination of transmucosal jet application for elevation of the mucosa with plasma expanders is therefore an interesting approach to optimize endoscopic mucosal resections.

A new device to simplify flexible endoscopic treatment of Zenker's diverticulum

BACKGROUND

Endoscopic treatment of a Zenker's diverticulum (ZD) is challenged by maintaining a stable position and visual field. An oblique transparent cap and an overtube have been used with success. The porcine hypopharyngeal pouch is similar to a ZD. While using the widespread EMR device (WEMR) in the esophagus, we realized that the design may be advantageous for treatment of a ZD.

OBJECTIVE

To use the WEMR cap device to incise the porcine hypopharyngeal pouch septum.

DESIGN

WEMR cap incision of the porcine hypopharyngeal pouch septum.

SETTINGS

Animal laboratory.

INTERVENTIONS/METHODS

Six female domestic pigs underwent endoscopy with the prototype WEMR cap. The cutting wire incised the hypopharyngeal-esophageal septum. Three pigs were immediately euthanized and underwent neck dissection. Three pigs were keep alive for 3 weeks and then underwent excisional neck dissection.

RESULTS

The procedure was technically easy. The average time was 10 minutes. Limited bleeding occurred by using cutting current and was eliminated by blended current. The entire septum could be incised with the cap edges working as a stopper, until the septum almost completely disappeared. No overt complications occurred. A follow-up endoscopy showed a small residual septum and scar. A barium swallow revealed no pouch, with ready passage into the esophageal lumen.

CONCLUSIONS

The WEMR wire-cutting cap can incise the hypopharyngeal septum in an animal model simulating ZD. This device has the advantage of providing a stable position throughout the procedure and a protective rim that controls the incision. The device facilitates this procedure.

Autologous blood as a submucosal fluid cushion for endoscopic mucosal therapies: results of an ex vivo study

OBJECTIVE

Submucosal injection of fluid is used to elevate lesions in order to prevent perforation, which is the most calamitous complication during endoscopic resection therapies. There are several injection options when performing mucosal elevation (normal saline (NS), sodium hyaluronate (SH), etc.). Submucosal injection of fresh, autologous blood offers some advantages because of its specific properties: corpuscular components ensure prolonged elevation and procoagulatory constituents prevent post-interventional bleeding. The purpose of this study was to compare the ex vivo performance of autologous blood as a submucosal fluid cushion (SFC) with that of NS, SH and DW (dextrose water).

MATERIAL AND METHODS

The proximal third of a resected porcine stomach was cut into squares. One millilitre NS, DW, SH and fresh porcine blood was injected into the submucosa. The height and duration of the submucosal injections were objectively measured during 1 h. Mucosal elevations were resected using an electro snare.

RESULTS

The initial height and width of the mucosal elevations were comparable for SH and blood, and significantly higher compared with NS and DW. Mucosal elevation after injecting autologous blood persisted significantly longer compared with NS (p <0.05), but did not differ from hyaluronate. Histopathological examination of the resected specimen confirmed the appropriate submucosal injection of these substances.

CONCLUSIONS

Submucosal injection of autologous blood with a standard endoscopic injection needle is possible and generates adequate mucosal elevation for the resection of high-quality specimens. This procedure could offer a "gratis" option for SFC as opposed to the expensive SH. Further clinical studies are needed to substantiate its use.

State of the art on endoscopic mucosal resection and endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) provide new alternatives for minimally invasive treatment of superficial gastrointestinal malignancies. Evidence suggests that these techniques can be performed safely and have comparable outcomes to surgery with less morbidity and better quality of life due to their tissue-sparing nature when compared with conventional surgery. Although the techniques and accessories have become standardized, there is room for improvement, and further research and development are required. Current challenges facing American gastroenterologists or endoscopic surgeons include access to training and lack of appropriate reimbursement for these heavy-weighted and technically demanding procedures. Nevertheless, EMR and ESD are here to stay and are only the first steps toward true radical endoluminal resection of GI malignancies.

Novel techniques and instrumentation for EMR, ESD, and full-thickness endoscopic luminal resection

Endoscopic intervention is evolving into an established therapeutic alternative for small superficial lesions, and an eventual application for en bloc resection of large lesions, deeper layers, and a reliable access to lesions outside of the gastrointestinal wall. Although further developmental and clinical evaluation is necessary, we believe endoscopic resection by the submucosal route and by full-thickness approaches will replace standard surgical procedures in the next several years.

Selective fluid cushion in the submucosal layer by water jet: advantage for endoscopic mucosal resection

BACKGROUND/AIM

Numerous new techniques have recently been reported and described for the endoscopic mucosal resection of large superficial lesions of the gastrointestinal tract. We present here for the first time the application of a water jet dissector for mucosa elevation.

MATERIALS AND METHODS

In an ex vivo study, the effectiveness of a water jet dissector (Helix Hydro-Jet) placed directly on the stomach walls of 8 pigs was examined to create a mucosal elevation. After having determined optimal pressures, angle of application, and application times, 13 submucosal fluid cushions were produced in different areas of the stomach walls of 8 pigs in vivo, and the sizes of the resulting submucosal cushions were measured.

RESULTS

Using pressures between 30 and 70 bar, it was routinely possible to create submucosal fluid cushions in the stomach wall ex vivo as well as in vivo. Histological examination showed a selective edema in the submucosa without damage to the deeper mucosal layers of the gastric wall.

CONCLUSIONS

The capacity of a targeted high-pressure water jet to penetrate the mucosa and selectively create a fluid cushion in the submucosa facilitates endoscopic resection of the mucosa. This new method could contribute to ameliorate the endoscopic treatment of mucosal tumors which previously could not be resected endoscopically due to their size, extent, or location.

Endoluminal therapy for Barrett's esophagus

This article reviews methods to minimize the complications associated with endoscopic therapy for patients with Barrett's esophagus. To place this discussion in context, the natural history of Barrett's esophagus and the risks associated with progression to dysplasia and invasive carcinoma are reviewed. Operative esophageal resection traditionally is recommended for patients with Barrett's high-grade dysplasia and early carcinoma, and these surgical risks also are reviewed. Finally, all currently approved and commercially available methods for endoscopic ablation and resection of Barrett's disease are categorized according to their application methods of ablation: focal ablation, field ablation, and mucosal resection. The clinical experience with these devices is reviewed with their associated adverse events and complications. Caveats, concerns, and recommendations are discussed to help minimize the complications associated with the use of these important technologies that hold the promise of removing or destroying Barrett's disease to prevent the development of invasive carcinoma.

Extended endoscopic mucosal resection in the esophagus and hypopharynx: a new rigid device

We present a new device allowing for the diagnosis and treatment of extended superficial lesions of the esophagus and hypopharynx such as early squamous cell carcinoma, intestinal metaplasia with high grade intraepithelial neoplasia or early adenocarcinoma arising in Barrett's esophagus. A new modified rigid esophagoscope (Karl Storz GmbH, Germany) has been designed. A large mucosal area is sucked against a transparent and perforated hemi-cylindrical window. Mucosal resection is performed by an electrical wire loop at a constant depth of 1 +/- 0.1 mm. The resected surface varies from 4 to 12 cm(2). Circumferential resection consists of two opposite individual hemi-circumferential resections. We performed three series of animal trials: hemicircumferential mucosectomies; circumferential resections of variable (2 to 6 cm) length and long-segment mucosectomies with follow-up. Hemi- and circumferential resections could be done in one or two specimens only which allowed precise histological studies. This facilitated easy orientation and analysis of the surgical margins. The deep resection margin was precisely located at the submucosal level, a prerequisite for a safe resection of superficial cancers of the esophagus and hypopharynx.

Endoprevention of esophageal cancer: endoscopic ablation of Barrett's metaplasia and dysplasia

This review describes the use of endoscopic therapy for the treatment of Barrett's disease and the prevention of esophageal carcinoma, predominantly a disease of older white men. While the term endoprevention may be novel, gastroenterologists have been using endoscopic techniques to prevent colon cancer for decades. For the endoprevention of Barrett's carcinoma, the regulatory approval for the use of porfimer sodium photodynamic therapy was an important milestone, as this treatment has been proven to safely ablate Barrett's glandular epithelium, including high-grade dysplasia, and significantly decrease the risk for the development of invasive cancer in several single-center studies, a prospective multicenter randomized controlled study using expert centralized histopathology analysis and long-term single-center results. Newer methods of mucosal ablation, such as the radiofrequency balloon, have been developed for the treatment of patients with Barrett's metaplasia or dysplasia. These newly developed techniques are able to treat large fields of glandular epithelium in a short treatment procedure using safe, effective, durable methods for the complete ablation of Barrett's metaplasia and low-grade dysplasia. These techniques may finally allow the interventional gastrointestinal endoscopist to prevent the development of esophageal carcinoma, just as colonoscopy with polypectomy has prevented colon cancer. However, it will be critically important to document the safety, durability and efficacy of these devices. Ultimately, the impact of successful Barrett's ablation on the incidence of Barrett's carcinoma, and the need for postablation surveillance endoscopy must be determined.

Extensive circumferential endoscopic mucosal resection with a new rigid esophagoscope: an animal study

OBJECTIVE

Current endoscopic mucosal resection techniques are suboptimal for large circumferential mucosal resections intended to treat Barrett mucosa with multicentric foci of high-grade intraepithelial neoplasia or early adenocarcinomas. A rigid modified endoscope was developed for extended endoscopic mucosal resection in the esophagus. This pilot animal study investigated the feasibility of circumferential endoscopic mucosal resections of different lengths in the sheep esophagus.

METHODS

Circumferential esophageal endoscopic mucosal resections of 2.2 cm (n = 6), 3.3 cm (n = 6), 4.4 cm (n = 7), and 5.5 cm (n = 5) were performed in 24 sheep. Circumferential resections consisted of two opposite hemicircumferential mucosectomies. Animals were followed up with endoscopic examinations at 1 week and then monthly to 6 months, or until complete re-epithelialization without stenosis eventually ensued. Strictures were treated with a single or repeated dilatations with Savary bougies.

RESULTS

Circumferential resections 2.2 to 5.5 cm in length were successfully performed in 23 of 24 of the animals. One perforation occurred directly after mucosectomy. Accurate depth of resection through the submucosa was obtained in 85% of the specimens. Cicatricial stenosis was controlled in 95% by bougienage.

CONCLUSION

Endoscopic mucosal resection performed with the rigid esophagoscope allowed extensive circumferential resections in a single session. There is thus potential to eradicate complete Barrett esophagus with high-grade intraepithelial neoplasia or early adenocarcinomas.

Photodynamic therapy for Barrett's esophagus with high-grade dysplasia

This article describes advances in photodynamic therapy for patients with Barrett's esophagus and high-grade dysplasia-an important, minimally invasive treatment option proven to safely and durably ablate Barrett's dysplasia and prevent carcinoma while preserving the gastroesophageal junction.

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.

Advanced polypectomy

Advanced polypectomy includes the approach to large polyps, polyps that are difficult to access, and polyps that require special maneuvers for removal. Sessile polyps are considered difficult to remove, the larger diameters falling into the "very difficult" category, requiring advanced polypectomy techniques. Some pedunculated polyps may require advanced techniques. Most polyps in the colon are sessile, and many of these are located in the right colon, from the hepatic flexure to the cecal caput. Pedunculated polyps, with a pedicle of pulled-out mucosa and submucosa caused by the constant action of peristalsis in the colon's attempt to evacuate the polyp, usually are located in the sigmoid colon.

Uses of photodynamic therapy in premalignant and malignant lesions of the gastrointestinal tract beyond the esophagus

Much has recently been written regarding the use of photodynamic therapy for the treatment of esophageal carcinoma and dysplastic Barrett's esophagus. This review, however, describes the clinical experience using photodynamic therapy with various photosensitizer agents for the treatment of diseases in other areas of the gut, especially the pancreaticobiliary tract where European studies have established the role of porfimer sodium photodynamic therapy in the management of patients with cholangiocarcinoma.

Endoscopic mucosal resection: treatment of neoplasia

Techniques of endoscopic mucosal resection (EMR) can dramatically improve the ability to diagnose and treat superficial lesions in the gastrointestinal (GI) tract. Early cancers, submucosal tumors, and sessile polyps can be safely and completely removed in a single procedure, with long-term outcome results comparable to surgery. This is accomplished with a minimum cost, morbidity, and mortality and with little or no impact on the quality of life of patients. This article provides an overview of the techniques, indications, and outcomes of EMR in the management of GI malignancy.

Emerging endoscopic techniques in oncology

New techniques have expanded the role of endoscopy in the diagnosis, staging, therapy, and palliation of malignancies. Three major areas of emerging technologies--endoscopic ultrasound (EUS), luminal stent technology, and photodynamic therapy (PDT)--are discussed in this article. Although EUS and PDT have been used for more than two decades, they have only recently emerged as established integral methods in the armamentarium of the gastrointestinal endoscopist.

Endoscopic treatment of high-grade dysplasia and early cancer in Barrett's oesophagus

Barrett's oesophagus is the premalignant precursor of oesophageal adenocarcinoma. Non-dysplastic metaplasia can progress to low-grade dysplasia, high-grade dysplasia, and finally to invasive cancer. Although the frequency of adenocarcinoma in patients with Barrett's oesophagus is low, surveillance is justified because the outcome of adenocarcinoma is poor. Oesophagectomy remains the standard treatment for patients with high-grade dysplasia and superficial carcinoma. However, it has been associated with substantial morbidity and mortality and some patients are judged unfit for surgery. In this review, the present status of less invasive procedures is discussed. Endotherapy preserves the integrity of the oesophagus and allows a better quality of life to patients at low risk of developing lymph-node metastases. Opposition to endoscopic treatment is based mainly on the identification of undetected foci of cancer and high-grade dysplasia in oesophagectomy samples. The current ablative techniques used are photodynamic therapy, argon plasma coagulation, laser treatment, and endoscopic mucosal resection.