Comparison of a portable disposable large-channel gastroscope and a conventional reusable gastroscope in gastric endoscopic submucosal dissection

Abstract

BACKGROUND

Conventional reusable endoscopes have high disinfection costs because of their large size. In this study, we compared the effectiveness, safety, and operation performance of the portable disposable large-channel endoscope that we developed with those of a conventional gastroscope in endoscopic submucosal dissection (ESD).

AIM

To compare two gastroscopes in ESD for effectiveness and safety.

METHODS

Ten Bama pigs were subjected to gastroscopy and ESD after general anesthesia. The experiment was completed by four experienced endoscopists. First, two endoscopists randomly selected the portable disposable large-channel or conventional gastroscope to complete gastroscopy procedures. The other two endoscopists assessed the quality of endoscopic images. After endoscopy, all of the endoscopists randomly used the portable disposable large-channel endoscope or the conventional gastroscope for ESD. Endoscopic operation performance, submucosal dissection time, total procedure time, total submucosal injection volume, specimen size, success rate of en bloc resection, muscular injury rate, and complications were compared between the endoscopes.

RESULTS

No significant differences in gastroscopy duration or in the integrity, sharpness, saturation, and brightness of the gastroscopic images were observed between the gastroscopes. For ESD, no significant differences in endoscopic operation performance, incision time, submucosal dissection time, total procedure time, total submucosal injection volume, specimen size, or success rate of en bloc resection were observed between the gastroscopes. Neither gastroscope caused muscular injury or treatment-related complications.

CONCLUSION

The portable disposable large-channel endoscope can be used safely and effectively for gastroscopy and treatment.

Key Words: Portable gastroscope; Disposable gastroscope; Large-channel; Endoscopic submucosal dissection; Endoscopic Images; Treatment Efficiency; Cross-infection; Cost Savings

Core Tip: The aim of this study was two-fold: (1) To evaluate the safety and feasibility of the portable disposable large-channel endoscope for gastrointestinal examination and endoscopic submucosal dissection through animal experiments; and (2) To evaluate the quality of the endoscopic images, operational performance, and treatment efficiency. The results showed that the portable disposable large-channel endoscope can be used safely and effectively for gastroscopy and treatment.

INTRODUCTION

Gastrointestinal endoscopy is an important tool for diagnosing and treating digestive system diseases. Gastrointestinal endoscopy procedures are performed tens of millions of times each year in China. However, a conventional gastroscope system is expensive and bulky and requires cumbersome cleaning and disinfection steps and specific operation environments. Therefore, substantial manpower, material resources, and funds are needed to maintain a gastroscope system.

Due to the widespread application of gastrointestinal endoscopy, endoscopy-related iatrogenic infections should be addressed. The most common cause of endoscopy-related iatrogenic infections is inadequate procedures related to endoscope cleaning, disinfection, and drying[1]. Microbes can remain in an endoscope even after specialized cleaning and disinfection and thus can lead to the spread of infections. Therefore, an increasing number of teams have sought to develop disposable endoscopes, such as disposable bronchoscopes, disposable duodenoscopes, and disposable ureterorenoscopes, and the clinical benefits of such equipment have been confirmed[2].

Due to advances in medical device technology and the increasing demand for medical devices in clinical use, medical device miniaturization and portability have been prioritized, and portable endoscopes for various applications (e.g., portable laparoscopes, portable laryngoscopes, and portable colposcopies) have been developed. Portable medical devices can be used in a broad range of places and contexts and allow for the immediate diagnosis and rapid treatment of diseases.

To date, the research and development of portable disposable gastrointestinal endoscopes are relatively limited, and portable disposable gastrointestinal endoscopes can be applied only to the examination of the digestive tract and cannot be used for the treatment of digestive tract diseases. Therefore, we developed a portable disposable large-channel endoscope that can be used not only to examine the digestive tract but also to treat digestive system diseases. Our design includes a large-diameter working channel, which improves treatment capacity and efficiency. The aim of this study was two-fold: (1) To evaluate the safety and feasibility of using the developed portable disposable large-channel endoscope in gastrointestinal examination and endoscopic submucosal dissection (ESD) through animal experiments; and (2) To evaluate the quality of endoscopic images, operational performance, and treatment efficiency.

MATERIALS AND METHODS

Experimental subjects

Ten Bama miniature pigs weighing approximately 25-30 kg were used in this study. After 2 days of fasting and 6 hours of water deprivation, the pigs were anesthetized with sodium pentobarbital (intravenous injection, 20 mg/kg) and mechanically ventilated. During the procedure, the pigs were kept in the left lateral position, and an experienced anesthesiologist maintained anesthesia and monitored vital signs. This study was reviewed and approved by the animal experiment committee of the Chinese PLA General Hospital (Beijing, China).

Experimental equipment

The portable disposable large-channel endoscope system was developed by the Department of Digestive Diseases of the Chinese PLA General Hospital. The system is composed of an endoscopic host and a disposable large-channel gastroscope (Figure 1). The system parameters were as follows: 9.8 mm outer diameter, 3.4 mm channel inner diameter with 1450 mm length, 140° view angle with 3-100 mm depth of view, 180° up bending angle, and 160° down, left, and right bending angles. The volume of suction was 400 mL/min. The air and water supplies were 800 and 40 mL/min, respectively. The working time after charging was more than 6 hours. A conventional gastroscope (GIFQ260J; Olympus, Tokyo, Japan) was used in this study.

Figure 1 Portable disposable large-channel endoscope system (model HG-GS100). In this figure, the main components of the portable disposable large-channel endoscope system are shown. The endoscopic host is responsible for powering and controlling the endoscope. The disposable large-channel gastroscope has a distinct structure. The outer diameter of the gastroscope is 9.8 mm, and the channel inner diameter is 3.4 mm with a length of 1450 mm. The tip of the gastroscope contains important components such as the light-emitting diode for illumination, the camera for image capture, and the working channel through which various endoscopic tools can be inserted. The bending section of the endoscope allows for flexible maneuverability during the examination, with an up-bending angle of 180° and down, left, and right bending angles of 160°. These components work in concert to enable effective endoscopic procedures.

Experiment 1: Performance of the gastroscopes and the quality of endoscopic images were evaluated through gastroscopy

Experimental method: Two experienced endoscopists randomly selected (coin toss) the portable disposable large-channel endoscope or conventional gastroscope to perform gastroscopy on each Bama miniature pig. A total of 31 standardized endoscopic images were obtained, namely, the oropharynx, upper and middle esophagus, lower esophagus, esophagogastric junction, gastric fundus, four walls of the upper gastric body (anterior wall, posterior wall, lesser curvature, greater curvature), four walls of the middle gastric body, four walls of the lower gastric body, anterior wall of the gastric angle, posterior wall of the gastric angle, lesser curvature of the gastric angle, greater curvature of the gastric angle, four walls of the gastric antrum, pylorus, four walls of the duodenal bulb, and descending part of duodenum. The total duration of each gastroscopy procedure was recorded. Images collected during each gastroscopy were independently evaluated and scored by the other two endoscopists, and any discrepancy was resolved by a third researcher.

Evaluation indicators: For each image, we referred to some articles[3-5] and evaluated the following aspects: (1) Image integrity-an image received one point when the anatomical structure in the image was intact; otherwise, the image received zero points; (2) Sharpness-an image received one point when the details of the anatomical structure in the image were clearly discernible; otherwise, the image received zero points; (3) Saturation-an image received one point when the colors were vibrant and met the clinical requirements; otherwise, the image received zero points; and (4) Brightness-an image received one point when the image was uniformly and fully illuminated; otherwise, the image received zero points.

Experiment 2: Operational performance of the gastroscopes and their effectiveness and safety in ESD was evaluated with ESD

Experimental method: Four endoscopists with ESD experience completed the ESD. Four hypothetical lesions with a diameter of approximately 2 cm in the gastric body and gastric antrum were examined for each pig. The hypothetical lesions were resected using a conventional or portable disposable large-channel gastroscope. Before the experiment, the four endoscopists first used the lottery method to determine the order in which they would operate, and then each endoscopist was given a sealed envelope containing the type of gastroscope to be used (disposable or conventional gastroscope) and operation site (gastric body or antrum). During the operation, the submucosal dissection time, total procedure time of ESD, total submucosal injection volume, specimen size, success rate of en bloc resection, muscular injury rate, and complications were recorded. After the operation, each surgeon scored the performance of the endoscopes.

Evaluation indicators: The submucosal dissection time was defined as the time from the start of dissection after the end of the circumferential resection to the complete dissection of the specimen. The total procedure time of ESD was defined as the time from the start of the submucosal injection to the completion of the removal of the resection specimen. The total submucosal injection volume was defined as the total volume of fluid injected during the entire ESD operation. Moreover, we assessed the operation performance of the endoscopes in terms of image acquisition, water supply, air supply, suction, large-knob operation, small-knob operation, body rigidity, field of view (FOV), light illumination, tip flexibility, and working channel. Each item was scored using the following criteria[3-4]: Four points for fully meeting the clinical operation requirements, three points for meeting the clinical operation requirements but having slight defects, two points for completing the clinical operation but having obvious defects, one point for initially failing to meet the clinical operation requirements but meeting the requirements after considerable improvement, and 0 points for complete failure.

Operation procedure for ESD: The entire procedure included five steps: Marking, lifting, circumferential resection, dissection, and wound management. First, a transparent cap was installed on the front end of the gastroscope. After the gastroscope reached the hypothetical lesion site, the lesion was marked with an electrosurgical knife. Then submucosal injection (normal saline and a small amount of methylene blue solution) was performed at multiple sites on the periphery of the lesion to lift the lesion up completely. Subsequently, an electrosurgical knife was used in making an incision along the edge of the mucosa. After the circumferential resection was complete, the lesion was dissected until the specimen was completely removed. During the operation, the lesion was fully lifted up by multiple submucosal injections. When bleeding occurred, an electrosurgical knife or hot biopsy forceps were used to stop the bleeding. After the complete dissection of the lesion, the wound was observed for complications such as active bleeding, muscular injury, and perforation. When active bleeding, muscular injury, or perforation occurred, further hemostasis or closure of the perforation were performed.

Statistical analysis

We used SPSS version 25.0 (IBM SPSS Statistics, Chicago, IL, United States) for data analyses. The t-test, χ² test, and Mann-Whitney U test were performed for the appropriate data types. P < 0.05 was considered statistically significant.

RESULTS

Assessment of gastroscopy performance and endoscopic image quality

Gastroscopy was performed 10 times with the portable disposable large-channel gastroscope and 10 times with the conventional gastroscope. Each gastroscopy was successfully completed, and endoscopic images were successfully collected (Figure 2). No significant differences in the duration of gastroscopy (287.33 ± 38.15 s vs 284.78 ± 70.75 s; P = 0.673), image integrity scores (30.80 ± 0.42 points vs 30.90 ± 0.32 points; P = 0.739), image sharpness scores (30.50 ± 0.71 points vs 30.80 ± 0.42 points; P = 0.436), image contrast scores (30.10 ± 1.20 points vs 30.80 ± 0.42 points; P = 0.218), and image brightness scores (29.67 ± 1.23 points vs 30.67 ± 0.50 points; P = 0.203) (Table 1) were found between the portable disposable large-channel endoscope group and Olympus endoscope group (i.e. conventional gastroscope group).

Figure 2 Endoscopic image obtained by the portable disposable large-channel endoscope system. A: Oropharynx. This area is the initial part of the digestive tract examined during gastroscopy. Clear visualization of the oropharynx is crucial as it can help detect any abnormalities such as inflammation, tumors, or structural defects; B: Esophagus. The esophagus is a key passage for food and liquid transport. Endoscopic examination of the esophagus can identify conditions like esophagitis, esophageal varices, or early-stage cancers. The clear and sharp image of the esophagus obtained by the portable disposable large-channel endoscope system allows for accurate diagnosis; C: Esophagogastric junction. This is the transition area between the esophagus and the stomach. It is an important site for detecting gastroesophageal reflux disease, Barrett's esophagus, and some types of cancer. The image integrity and quality at this junction are essential for proper diagnosis; D: Gastric fundus. The gastric fundus is the upper part of the stomach. It stores food temporarily and plays a role in the initial digestion process. Observing the gastric fundus can help diagnose diseases such as gastric polyps or gastric ulcers; E: Gastric body. The gastric body is the main part of the stomach where most of the digestion and absorption processes occur. Endoscopic evaluation of the gastric body can detect various diseases, and the high-quality image from the endoscope helps in accurate assessment; F: Gastric angle. The gastric angle is a critical anatomical structure for endoscopic examination. It can be a challenging area to visualize clearly, but the portable disposable large-channel endoscope system provides clear images, facilitating the detection of any lesions or abnormalities; G: Gastric antrum. The gastric antrum is involved in the mixing and propulsion of food in the stomach. Abnormalities in this area, such as gastritis or tumors, can be detected through endoscopic images; H: Duodenum. The duodenum is the first part of the small intestine. Endoscopic examination of the duodenum can help diagnose conditions like duodenal ulcers, duodenitis, and some types of tumors. The high-quality images obtained by the endoscope system contribute to accurate diagnosis and treatment planning.

Table 1 Assessment of gastroscopy performance and endoscopic image quality, mean ± SD.

	Experimental group (n = 10)1	Control group (n = 10)2	P value
Duration of gastroscopy	287.33 ± 38.15	284.78 ± 70.75	0.673
Image integrity scores	30.80 ± 0.42	30.90 ± 0.32	0.739
Image sharpness scores	30.50 ± 0.71	30.80 ± 0.42	0.436
Image contrast scores	30.10 ± 1.20	30.80 ± 0.42	0.218
Image brightness scores	29.67 ± 1.23	30.67 ± 0.50	0.203

¹Portable disposable large-channel gastroscope.

²Conventional reusable gastroscopes.

Evaluation of gastroscopy performance and effectiveness and safety of ESD

ESD was performed 20 times with the portable disposable large-channel gastroscope (Figure 3) and 20 times with the conventional gastroscope. No significant differences in operational performance scores (image acquisition, water supply, air supply, suction, large-knob operation, small-knob operation, body rigidity, FOV, light illumination, tip flexibility, and working channel; all were P > 0.05) were found between the endoscopes. In the conventional gastroscope group, image acquisition, air supply, large-knob operation, small-knob operation, body rigidity, FOV, tip flexibility, and working channel completely met the clinical operation requirements in all 20 operations (all four points). Regarding the disposable portable gastroscope group, image acquisition, suction, FOV, light illumination, tip flexibility, and working channel completely met the clinical operation requirements in all 20 operations (all four points); small-knob operation was obviously defective in one operation, but the clinical operation was completed (two points; Table 2).

Figure 3 Endoscopic submucosal dissection was performed with the portable disposable large-channel gastroscope. A: Marking: Marking is the first step in endoscopic submucosal dissection (ESD). It is used to demarcate the boundary of the lesion clearly. This is crucial as it determines the resection margin and ensures complete removal of the lesion. The accurate marking ability of the portable disposable large-channel endoscope system is essential for successful ESD; B: Lifting: Lifting the lesion through submucosal injection is a key step. It separates the lesion from the deeper layers of the digestive tract, making it easier to resect and reducing the risk of perforation. The endoscope's ability to assist in precise lifting is important for the safety and effectiveness of the procedure; C: Circumferential resection: This step involves cutting around the marked lesion. A clear view provided by the endoscope is necessary to ensure a complete and accurate circumferential resection, which is vital for the en-bloc resection of the lesion; D: Dissection: During dissection, the lesion is carefully separated from the underlying tissues. The high-quality image and maneuverability of the portable disposable large-channel endoscope system enable the endoscopist to perform this delicate operation with precision, minimizing the risk of damage to surrounding tissues; E: Specimen: The removed specimen is an important outcome of ESD. The size and integrity of the specimen are used to evaluate the success of the resection and for pathological examination; F: Healing wound: After the ESD procedure, observing the healing wound is crucial. The endoscope can be used to monitor the wound for any signs of bleeding, infection, or improper healing. The clear image quality of the portable disposable large-channel endoscope system helps in accurate wound assessment.

Table 2 Comparison of the operational performance scores between the portable disposable large-channel gastroscope (experimental group) and conventional reusable gastroscopes (control group).

Operational performance	Score	Experimental group	Control group	P value
Image acquisition	0	0	0
	1	0	0
	2	0	0
	3	0	0
	4	20	20
Water supply	0	0	0	0.602
	1	0	0
	2	0	0
	3	3	1
	4	17	19
Air supply	0	0	0	0.602
	1	0	0
	2	0	0
	3	2	0
	4	18	20
Suction	0	0	0	0.289
	1	0	0
	2	0	0
	3	0	4
	4	20	16
Large-knob operation	0	0	0	0.602
	1	0	0
	2	0	0
	3	2	0
	4	18	20
Small-knob operation	0	0	0	0.108
	1	0	0
	2	1	0
	3	5	0
	4	14	20
Body rigidity	0	0	0	0.183
	1	0	0
	2	0	0
	3	5	0
	4	15	20
Field of view	0	0	0
	1	0	0
	2	0	0
	3	0	0
	4	20	20
Light illumination	0	0	0	0.183
	1	0	0
	2	0	0
	3	0	5
	4	20	15
Tip flexibility	0	0	0
	1	0	0
	2	0	0
	3	0	0
	4	20	20
Working channel	0	0	0
	1	0	0
	2	0	0
	3	0	0
	4	20	20

The en bloc resection of all hypothetical lesions was successfully completed using the portable disposable large-channel gastroscope and the conventional gastroscope. There were no significant differences in submucosal dissection time (median: 9.92 min [interquartile range (IQR): 8.19–16.30] vs 11.21 minutes [IQR: 9.06–13.25]; P = 0.864], total procedure time of ESD (median: 18.00 minutes [IQR: 12.11–23.80] vs 17.99 minutes [IQR: 14.82–20.51]; P = 0.938), total submucosal injection volume (median: 20.50 mL [IQR: 11.50–39.00] vs 20.50 mL [IQR: 14.00–23.00]; P = 0.767), and specimen size (median: 20.35 mm [IQR: 16.45–24.43] vs 18.72 minutes [IQR 17.04–21.12]; P = 0.501] between the portable disposable large-channel and conventional gastroscope groups. For both groups, no muscle layer injury occurred during ESD, and no complications occurred during or after ESD (Table 3).

Table 3 Comparison of the performance between portable disposable large-channel gastroscope (experimental group) and reusable gastroscopes (control group) in endoscopic submucosal dissection, median (25^th-75^th percentiles).

	Experimental group	Control group	P value
En bloc resection rate (%, n/n)	100% (20/20)	100% (20/20)	-
Submucosal dissection time (minutes)	9.92 (8.19, 16.30)	11.21 (9.06, 13.25)	0.864
Total procedure time of endoscopic submucosal dissection, minutes	18.00 (12.11, 23.80)	17.99 (14.82, 20.51)	0.938
Total submucosal injection volume (mL)	20.50 (11.50, 39.00)	20.50 (14.00, 23.00)	0.767
Specimen size, mm	20.35 (16.45, 24.43)	18.72 (17.04, 21.12)	0.501
Muscle layer injury	-	-	-
Complications	-	-	-

DISCUSSION

Our team developed a portable disposable large-channel endoscope. In this study, we compared the effectiveness, safety, and operation performance of the portable disposable large-channel gastroscope and those of a reusable conventional gastroscope in gastroscopy and ESD.

Successful gastric examination is the most basic function of a gastroscope. In this study, both types of gastroscope facilitated the successful completion of endoscopic examinations without causing any intraoperative complication. The gastroscopes were used in the standardized examination of the esophagus, cardia, gastric fundus, gastric body, gastric angle, gastric antrum, pylorus, and duodenum. No significant difference in the duration of gastroscopy was found, indicating that the portable disposable large-channel endoscope is highly ergonomic and compatible. Endoscopists successfully completed endoscopic operations at first use, demonstrating the potentially wide application of the portable disposable large-channel endoscope. Obtaining the high-quality endoscopic images of various parts is an important component of endoscopic examinations. The obtained endoscopic images were evaluated for integrity, sharpness, saturation, and brightness. The images obtained using the portable disposable large-channel endoscope were basically intact, and their sharpness, saturation, and brightness were not different from those obtained using the conventional gastroscope. This result indicates that the portable disposable large-channel endoscope system can meet the performance requirements of upper gastrointestinal examinations.

Furthermore, we compared the application of two types of gastroscope in ESD. We focused on evaluating the performance of the portable disposable large-channel endoscope. The quality of the operating system directly affected the use of an endoscope, and the endoscopes were evaluated in terms of image acquisition, water supply, air supply, suction, large-knob operation, small-knob operation, body rigidity, FOV, lighting illumination, tip flexibility, and working channel. No statistically significant differences in the abovementioned aspects were found between the gastroscopes. However, the endoscopist gave an evaluation score of two points for small-knob operation in one operation involving the portable disposable large-channel endoscope because he believed that although he was able to complete the endoscopic operation, he found obvious defects in small-knob operation. The endoscopists gave an evaluation score of three points for small-knob operation in five endoscopic operations because of defects in the small-knob operation. Although the statistical results indicated that the gastroscopes showed no differences in small-knob operation, the sample size may have been extremely small for identifying a difference. Had the sample size been further expanded, the difference would have become noticeable. The endoscopists who reported defects in the small-knob operation noted that solely adjusting the small knob can cause the slight rotation of the large knob, resulting in the failure of the endoscope tip to accurately reach the expected position. Therefore, in subsequent research and development, we will further optimize the performance of the small knob. The endoscopists reported slight defects in the water supply function in three operations involving the disposable gastroscope, and they indicated that the sensitivity of the water supply function of the disposable gastroscope was slightly lower than that of the conventional gastroscope. The endoscopists reported slight defects in the air supply function in two operations involving the portable disposable large-channel endoscope. Although the air supply function of the portable disposable large-channel gastroscope has three levels (low, medium, and high), the air supply rate might still be not fast enough. The endoscopists reported slight defects in the large-knob operation in two operations involving the portable disposable large-channel gastroscope because of the slight loosening of the large knob. The endoscopists reported slight defects in body rigidity in five operations involving the portable disposable large-channel gastroscope because the endoscopists were accustomed to using the conventional Olympus gastroscope. The portable disposable large-channel gastroscope was different from the conventional Olympus gastroscope in terms of tactile feeling, body rigidity, and maneuverability because of the rubber and polycarbonate materials in the body of the disposable gastroscope. However, this difference did not have an actual impact on gastroscope operation. Although no significant difference in suction or light illumination was found between the gastroscopes, the portable disposable large-channel gastroscope seemed to have better suction and light illumination. No defects were reported in the suction or light illumination of the portable disposable large-channel gastroscope, but slight defects were reported in those of the conventional gastroscope (four and five times, respectively). During ESD, bleeding may occur in surgical FOV. Thus, quickly clearing the surgical FOV, quickly locating the site of bleeding, and stopping bleeding immediately are important. Our large-channel design facilitates FOV clearing and reduces the risk of the channel being blocked by food residues or blood clots, laying the foundation for improving suction efficiency and achieving rapid hemostasis. Given that the Olympus gastroscope used in this study was not brand new (that is, it had been in use for a while), its light illumination intensity was lower than that of the portable disposable large-channel gastroscope. Thus, the illumination and clarity of the FOV were affected, and the portable disposable large-channel gastroscope was superior to the conventional gastroscope in maintaining optimal properties and eliminating challenges associated with the maintenance and replacement of components. ESD is of great importance to the treatment of digestive system diseases but is a delicate and difficult operation. We compared the performance of the two types of gastroscope in ESD in terms of submucosal dissection time, total procedure time of ESD, total submucosal injection volume, specimen size, success rate of en bloc resection, muscular injury rate, and complications. No differences in total submucosal injection volume, specimen size, or success rate of en bloc resection were found between the gastroscopes. Neither gastroscope caused any muscular injury. The Bama pigs showed stable vital signs during the operation, had no intraoperative or postoperative complications, and survived well after the operation. These findings indicate that the performance of the portable disposable large-channel gastroscope can fully meet the clinical requirements for endoscopy and be used in completing fine endoscopic treatments. Moreover, no difference in treatment performance was observed between the portable disposable large-channel and conventional gastroscopes. The former can be used as an alternative to the latter. When wound bleeding occurred during ESD, an electrosurgical knife or hot biopsy forceps were used to stop bleeding. The use of hot biopsy forceps may have caused an increase in the temperature of the endoscope because of the large contact area and large energy release. In addition, the tip was extremely delicate and easily damaged, and the light-emitting diode (LED) light bulb in the portable disposable large-channel gastroscope was installed on the tip. However, no tip damage occurred after repeated use of hot biopsy forceps, and the LED bulb provided stable lighting. These findings indicate that the quality of the portable disposable large-channel gastroscope met the clinical treatment standards.

Out-of-hospital rescue, bedside diagnosis and treatment, on-site treatment in battlefield military operations, and remote and accompanying health care have introduced new requirements (simplified structure and high portability) for the development of endoscopic technology beyond complete functionality, such as the development of compact, portable, and intelligent endoscopes[6]. The outbreak of the coronavirus disease 2019 pandemic and the emergence of monkeypox virus have made reducing the risk of cross-infection an important medical goal. The United States Food and Drug Administration recommend that “health care facilities and manufacturers begin transitioning to duodenoscopes with disposable components to reduce risk of patient infection”[7]. To reduce the risk of infection, hospitals have further refined endoscope cleaning and disinfection procedures. According to the guidelines provided by the Gastroenterological Nurses College of Australia and Gastroenterological Society of Australia[8], reprocessing typically consists of eight steps: Precleaning, leak testing, manual cleaning, rinsing after cleaning, visual inspection, high-level disinfection, rinsing after high-level disinfection, and drying. However, although detailed cleaning and disinfection procedures have been developed and a large amount of disinfection costs have been invested, iatrogenic infections caused by reusable gastroscopes still occur. Outbreaks have been reported in the United States, France, China, Germany, the Netherlands, and the United Kingdom. The causative organisms reported were Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Salmonella enteritidis[9]. The use of disposable endoscopes can solve the problem of cross-infection. The development of disposable bronchoscopes, disposable duodenoscopes, and disposable ureterorenoscopes is relatively mature, and these disposable endoscopes have been gradually implemented in clinical practice and have achieved efficacy comparable to those of reusable endoscopes[10-12]. In addition, the use of these disposable endoscopes can further achieve potential cost savings. Conventional gastroscope systems are bulky, cumbersome to clean and disinfect, and expensive to maintain, and maintaining and replacing their components are time consuming and laborious and require substantial costs. The use of disposable gastroscopes addresses some of these issues. A study on ureteroscopes noted that the use of disposable ureteroscopes can generate potential cost savings[13].

Previous studies on portable disposable gastroscopes are limited[3,14,15], only focusing on the application of disposable gastroscopes in gastroscopy. No studies have explored the application of disposable gastroscopes in the treatment of gastrointestinal diseases. In this study, we not only enlarged the working channel of the disposable gastroscope but also further explored its performance in endoscopic treatment.

This study had some limitations: (1) The sample size was small; thus, the performance of the disposable large-channel endoscope needs to be verified by studies with a larger sample size; (2) We preliminarily explored the application of the portable disposable large-channel endoscope in animals and will apply it clinically to verify its clinical efficacy; and (3) Although we expanded the working channel of the endoscope, the benefits of the large channel were not fully reflected in this study. Further experiments are needed to verify the benefits of this modification.

Using Bama miniature pigs as experimental subjects in this study offers several advantages. Bama miniature pigs have a gastrointestinal tract structure and physiological functions that are relatively similar to those of humans. Their stomach and intestinal anatomy, mucosal characteristics, and digestive processes share many similarities with human counterparts. This similarity allows for a more accurate simulation of human endoscopic procedures, such as gastroscopy and ESD. For example, the size and curvature of their esophagus and stomach are comparable to those of humans to a certain extent, enabling endoscopists to practice and evaluate the performance of the endoscopes in a more relevant environment. Moreover, Bama miniature pigs are widely available, and their relatively small size compared to other pig breeds makes them more convenient to handle in the laboratory setting. They are also docile in nature, which is conducive to the smooth progress of experimental operations. However, this experimental model also has some limitations. Although the gastrointestinal tract of Bama miniature pigs has similarities to that of humans, there are still differences in certain aspects. For instance, the microbiota composition in the digestive tract of pigs may vary from that of humans, which could potentially affect the endoscopic environment and the healing process after ESD. Additionally, the immune response of pigs may differ from that of humans, which might influence the occurrence and manifestation of complications during and after the operation. These differences may limit the direct extrapolation of the experimental results to the human clinical situation. Therefore, while the use of Bama miniature pigs provides valuable insights into the performance of the portable disposable large-channel endoscope, further clinical studies are needed to fully validate its safety and efficacy in humans.

To address the issue of the small sample size, in future studies, we plan to collaborate with multiple research centers. This multicenter approach will allow us to recruit a significantly larger number of experimental animals, such as increasing the number of Bama miniature pigs to at least 50. Additionally, we aim to include a diverse range of animal species, including other pig breeds and potentially nonporcine models with similar gastrointestinal characteristics to humans, like certain primates. This will enhance the generalizability of our findings and provide more robust evidence for the performance of the portable disposable large - channel endoscope.

For clinical verification of the endoscope's efficacy, we will design a prospective, randomized controlled clinical trial. We will enroll a sufficient number of patients with appropriate digestive tract diseases, such as early-stage gastric cancer or precancerous lesions suitable for ESD. The trial will be carefully monitored to assess not only the safety and effectiveness of the portable disposable large-channel endoscope but also patient-reported outcomes, such as comfort during the procedure. We will also closely observe any potential long-term complications, such as wound healing issues or recurrence of the disease.

Regarding the un-fully-realized benefits of the large-channel design, we will conduct a series of in vitro and in vivo experiments. In vitro, we will simulate various endoscopic scenarios, such as different levels of bleeding and the presence of different types of debris, to test the suction efficiency and the ability of the large-channel to prevent blockages more comprehensively. In vivo, we will perform ESD on a larger number of animals and use advanced imaging techniques, such as high-resolution confocal endomicroscopy, to visualize the treatment process in real-time and accurately evaluate how the large-channel affects the treatment efficiency and quality. Based on the results of these experiments, we will further optimize the design of the large-channel, for example, by adjusting its diameter, shape, or the material of the inner lining to enhance its performance.

CONCLUSION

The developed portable disposable large-channel endoscope can be used safely and effectively for gastroscopy procedures and treatment, can reduce iatrogenic infections, and broadens the location and context in which endoscopy is useful.