Endoscopic mucosal resection and endoscopic submucosal dissection for early gastric cancer: Current and original devices

Use of current automatic smoke evacuation system in flexible gastrointestinal endoscopy: Its feasibility and potential usefulness

Objectives

Flexible endoscopy does not have a system that can automatically evacuate surgical smoke generated in the gastrointestinal lumen. We aimed to investigate the feasibility and potential usefulness of automatic smoke evacuation systems in flexible endoscopy.

Methods

[Bench] After surgical smoke generated in the stomach was evacuated by the evacuator, the degree of residual smoke and gastric luminal collapse were evaluated to optimize the evacuator settings. [Animal] Insufflation, suction, and total operation time to complete the protocol of 10 cauterizations of the gastric mucosa were measured in three groups: "manual suction only," "manual suction with automatic evacuation (50% force)," and "manual suction with automatic evacuation (70% force)." The stability of endoscopic visualization and operability was evaluated by 10 endoscopists blinded to those suction settings, and the number of manual suctions, insufflations, and total operation time were measured.

Results

[Bench] The degree of residual smoke and gastric luminal collapse were inversely correlated. [Animal] When the automatic evacuator was partially used, there was no difference in the insufflation time, but the suction time (vs 50%; p = 0.011, vs. 70%; p = 0.011) and total operation time (vs. 50%; p = 0.012, vs. 70%; p = 0.036) were significantly reduced compared to manual operation only. Furthermore, manual suction with automatic evacuation (50% force) significantly improved the stability of endoscopic visualization and operability compared to manual operation only (p = 0.041, p = 0.0085).

Conclusions

The automatic smoke evacuation in flexible gastrointestinal endoscopy was potentially feasible and useful by improving the device setting.

Mathematical Analysis of Entropy Generation in the Flow of Viscoelastic Nanofluid through an Annular Region of Two Asymmetric Annuli Having Flexible Surfaces

In this manuscript, the authors developed the mathematical model for entropy generation analysis during the peristaltic propulsion of Jeffrey nanofluids passing in a midst of two eccentric asymmetric annuli. The model was structured by implementation of lubrication perspective and dimensionless strategy. Entropy generation caused by the irreversible influence of heat and mass transfer of nanofluid and viscous dissipation of the considered liquid was taken into consideration. The governing equations were handled by a powerful analytical technique (HPM). The comparison of total entropy with the partial entropy was also invoked by discussing Bejan number results. The influence of various associated variables on the profiles of velocity, temperature, nanoparticle concentration, entropy generation and Bejan number was formulated by portraying the figures. Mainly from graphical observations, we analyzed that, in the matter of thermophoresis parameter and Brownian motion parameter, entropy generation is thoroughly enhanced while inverse readings were reported for the temperature difference parameter and the ratio of temperature to concentration parameters.

Deployable, Variable Stiffness, Cable Driven Robot for Minimally Invasive Surgery

Minimally Invasive Surgery (MIS) imposes a trade-off between non-invasive access and surgical capability. Treatment of early gastric cancers over 20 mm in diameter can be achieved by performing Endoscopic Submucosal Dissection (ESD) with a flexible endoscope; however, this procedure is technically challenging, suffers from extended operation times and requires extensive training. To facilitate the ESD procedure, we have created a deployable cable driven robot that increases the surgical capabilities of the flexible endoscope while attempting to minimize the impact on the access that they offer. Using a low-profile inflatable support structure in the shape of a hollow hexagonal prism, our robot can fold around the flexible endoscope and, when the target site has been reached, achieve a 73.16% increase in volume and increase its radial stiffness. A sheath around the variable stiffness structure delivers a series of force transmission cables that connect to two independent tubular end-effectors through which standard flexible endoscopic instruments can pass and be anchored. Using a simple control scheme based on the length of each cable, the pose of the two instruments can be controlled by haptic controllers in each hand of the user. The forces exerted by a single instrument were measured, and a maximum magnitude of 8.29 N observed along a single axis. The working channels and tip control of the flexible endoscope remain in use in conjunction with our robot and were used during a procedure imitating the demands of ESD was successfully carried out by a novice user. Not only does this robot facilitate difficult surgical techniques, but it can be easily customized and rapidly produced at low cost due to a programmatic design approach.

Therapeutic options for early cancer of the esophagogastric junction

Early-stage (T1) esophagogastric junction cancer continues to represent 2-3% of all cases. Adenocarcinoma is the most frequent and important type, the main risk factors for which are gastroesophageal reflux and Barrett's esophagus with dysplasia. Patients with mucosal (T1a) or submucosal (T1b) involvement initially require a thorough digestive endoscopy, and narrow-band imaging can improve visualization. Endoscopic treatment of these lesions includes endoscopic mucosal resection, radiofrequency ablation and endoscopic submucosal dissection. Accurate staging is necessary in order to provide optimal treatment. The most precise staging technique in these cases is endoscopic ultrasound. The suspicion of deep invasion of the submucosa, presence of unfavorable anatomopathological characteristics or impossibility to perform endoscopic resection make it necessary to consider surgical resection.

Flexible robotic endoscopy: current and original devices

Two current major research topics concern the incorporation of flexible robotic endoscopy systems developed for natural-orifice translumenal endoscopic surgery (NOTES), primarily for the purpose of remote forceps operation, into endoscopic submucosal dissection (ESD) and other flexible endoscopic treatments and the use of robots for the manipulation of flexible endoscopes themselves with the aim of enabling the remote insertion of colonoscopes, etc. However, there are still many challenges that remain to be addressed; the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.

[Ongoing Development and Directions in Flexible Robotic Endoscopy]

The robotic system for flexible endoscopy was first developed as a platform enabling tissue triangulation in natural-orifice translumenal endoscopic surgery (NOTES). Then endoscopic submucosal dissection (ESD) was introduced and has widely been employed for the treatment of early gastrointestinal carcinoma. Subsequently, endoscopists became well aware of the limitations of their endoscopic manipulations with the conventional flexible endoscopes developed for diagnostic use, which led to the development of robotic systems for upper/lower gastrointestinal tract endoscopes intended for therapeutic use. Most flexible robotic endoscopes have 2 mechanical arms attached to the head, allowing surgeons to perform endoscopic manipulations, such as grasping, traction, incision, excision, and hemostasis. However, there are still many challenges that remain to be addressed: the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.

Progress in research of gastric intraepithelial neoplasia

Gastric carcinoma is one of the most common malignant tumors in the world, and the accurate diagnosis of precancerous lesions plays an important role in gastric cancer prevention. Intraepithelial neoplasia is a form of precancerous lesion of gastric cancer, and many efforts have been done to explore the relationship between gastric cancer and dysplasia. Recently, there has been much progress in the research of intraepithelial neoplasia, including genetic changes at the molecular level, the eradication of Helicobacter pylori (H. pylori), regular follow-up and endoscopic therapy. All of these will play an important role in clinical management of this condition. However, the etiological mechanism, influencing factors and malignant transformation of GIN are still unclear. Hence, further multi-center and long-term prospective studies are needed to solve these problems.

Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

The technique of endoscopic submucosal dissection (ESD) is now a well-known endoscopic therapy for early gastric cancer. ESD was introduced to resect large specimens of early gastric cancer in a single piece. ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate. However, the drawback of ESD is its technical difficulty, and, consequently, it is associated with a high rate of complications, the need for advanced endoscopic techniques, and a lengthy procedure time. Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.

[Endoscopic submucosal dissection: only for expert endoscopists?]

Endoscopic submucosal dissection (ESD) can be applied to early gastrointestinal cancers. This technique was developed to achieve radical curative resection and to reduce unnecessary surgical interventions. ESD was designed in eastern countries and is not widely used in the West. Although ESD represents a major therapeutic advance in endoscopy and is performed with curative intent, the complication rate (hemorrhage, perforation) is higher than reported in other techniques, requiring from endoscopists the acquirement of technical skill and experience through a structured and progressive training program to reduce the morbidity associated with this technique and increase its potential benefits. Although there is substantial published evidence on the applications and results of ESD, there are few publications on training in this technique and a standardized training program is lacking. The current article aims to describe the various proposals for training, as well as the basic principles of the technique, its indications, and the results obtained, since theoretical knowledge that would guide endoscopists during the clinical application of ESD is advisable before training begins. Training in an endoscopic technique has a little value without knowledge of the technique's aims, the situations in which it should be applied, and the results that can be expected.

An update in endoscopic management of gastric cancer

PURPOSE OF REVIEW

Gastric cancer remains a prevalent disease with a 5-year mortality rate of less than 25%. This review focuses on the endoscopic detection, staging, and management of gastric adenocarcinoma.

RECENT FINDINGS

Confocal laser endomicroscopy and narrow band imaging have a 77-99.4% sensitivity for early cancer detection, a significant improvement when compared with white light endoscopy. Proper staging can be accomplished through endoscopic ultrasound and multidetector row-computed tomography, with accuracy as high as 90.1%. Endoscopic management of early gastric cancer is minimally invasive and can be preferable to surgery. In properly selected patients, endoscopic submucosal dissection has been found to have 100% 5-year survival.

SUMMARY

The recent advances in gastric cancer have greatly improved the care we can offer our patients in gastric oncology. The emerging technologies will hopefully continue to promote this trend.

Development of a novel endoscopic manipulation system: The Endoscopic operation robot

AIM: To develop and evaluate the endoscopic operation robot (EOR). The EOR is a robot system designed specifically for remote manipulation of the scope during gastrointestinal endoscopy by a seated endoscopist.

METHODS: Total colonoscopy examinations using a colonoscopy training model were performed compared conventional insertion by manual manipulation and remote-controlled insertion, using the EOR. The author investigated the time taken for each of the 50 examinations.

RESULTS: The median insertion time (in minutes) for each 10 examinations (EOR vs manual manipulation) was 73.70 ± 25.37 vs 3.77 ± 1.34 in the first group, 38.40 ± 6.24 vs 3.40 ± 0.97 in the second group, 27.6 ± 4.01 vs 2.70 ± 0.95 in the third group, 23.8 ± 3.65 vs 3.10 ± 0.88 in the fourth group, and 22.9 ± 5.02 vs 2.60 ± 1.08 in the fifth group.

CONCLUSION: The study suggested the possibility of the clinical application of the EOR.