A novel magnetic retrieval system for button battery in upper gastrointestinal

doi:10.21203/rs.3.rs-2077846/v1

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A novel magnetic retrieval system for button battery in upper gastrointestinal

https://doi.org/10.21203/rs.3.rs-2077846/v1

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BACKGROUND: Endoscope can removes the button battery embedded in the esophagus，recommend emergency for symptomatic and asymptomatic children (< 2 hours) , For intragastric button batteries(BB), food debris may make positioning difficult. The smooth disc-shaped button battery allows foreign body forceps to grasp the battery Easy to slip off.Reasons for the delay include limited access to endoscopists, referral to tertiary care institutions, or delayed anesthesia due to gastric tamponade may all cause complications,In view of the extremely short effective treatment time window of the button battery in the upper gastrointestinal tract , this study designed a simple, fast and effective magnetic retrieval system for the button battery of the upper digestive tract.

Method: A set of magnetic retrieval system(MRS) for removing the upper digestive tract button battery was designed, including the magnetic retrieval device and the external guide magnet. We verified its feasibility by finite element analysis (FEA) simulation and removed button batteries with MRS in Beagle model.

Result: The button battery in the esophagus were all retrieved, No operation-related complications occurred. the retrieval time in the magnet group and endoscopic group was 92.91±82.47 s and 327.64±270.63 s respectively,P=0.012. 4 shifts happened in the endoscopic group during operation, 3 button batteries slipped off the forceps in the endoscopic group,resistance when retrieved was 2.1±1.02 N. The button battery in the stomach was all retrieved , the median time for magnetic aggregation using a guide magnet is 87s (70-135s), the median retrieved time was 21s (19-35s), and the resistance during the retrieved was 1.98N (1.67-2.4N).

Conclusion: we designed a novel magnetic retrieval system in this study. The MRS has a short magnetic retrieval time, is safe,cheapness and easy to operate, We suggest that the MRS could be used for the retrieval of BB during children ingestion button batteries.

magnetic retrieval system(MRS)

ingested button battery

magnetic surgery

With the wide application of button batteries in various toys, watches and remote controls, children inadvertently put button batteries into their mouths during play^[1]. Every year, about 10 people in every million people swallow button batteries, most of them children. One in every 1000 button battery intake will cause serious injury^[2]. Under normal circumstances, the button battery is smoothly discharged from the body through the digestive tract. However, once the button battery is forced to stay somewhere in the digestive tract, especially the three physiological stenosis of the esophagus, the button battery can cause serious complications and even death^{[3, 4]}, even after removing the button battery for a long period of time, children may suffer from the long-term sequelae of button battery ingestion. The mechanism of button battery damage may include leakage of alkaline battery contents, heavy metal ingestion, and local pressure damage leading to ischemic necrosis, but the most important mechanism is that the esophageal tissue contacts the anode and cathode to form a local circuit, which will quickly lead to liquid hydrolysis and the formation of hydroxides, resulting in alkaline corrosion^[5], and it has been proved that within 2 hours of ingestion, it will cause clinically serious ulcers and esophageal perforation, even shorter than this time. In the dog experiment of Tanaka et al., obvious mucosal damage reached the lamina propria within only 15 minutes, and extended to the outer muscular layer of the esophagus in 30 minutes^[6]. The clinical manifestations of button battery insertion vary from patients with normal vital signs to dysphagia and intermittent vomiting to patients with hemorrhagic shock^[7]. A more difficult diagnosis is that ingestion usually occurs in the population of children without witness evidence, further increasing the difficulty of diagnosis. Obviously, time control is very important in the management of button battery ingestion, the purpose is to quickly identify and remove foreign objects. Once there is any suspicious clinical symptoms, chest and neck X-ray examination is the most important diagnostic method. Imaging features: the X-ray film has a "bilateral" or "halo" sign in frontal view, which can helps to differentiate BB from coin ingestion. (the latter looks solid) ^[8]. The side piece can show the "stepped shape" when the anode with smaller diameter protrudes from the battery.It should be noted that for very thin button batteries, the steps are too small to be identified on the X-ray (these button batteries usually do not stay in In the esophagus); its negative pole is the most damaged part, so its position can also predict the location of subsequent complications^[9], and pay attention to whether there is the possibility of free air and perforation.

Rapid diagnosis and removal of button batteries are the most important^[10]. The European Society of Gastrointestinal Endoscopy (ESGE) and European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) both recommend emergency for symptomatic and asymptomatic children (< 2 hours) ,Endoscope removes the BB embedded in the esophagus^{[11, 12]}. Endoscopic foreign body forceps removal is an established method for the treatment of esophageal foreign body^{[13, 14]}. For intragastric BBs, food debris may make positioning difficult. The smooth disc-shaped BB allows foreign body forceps to grasp the battery easy to slip off. Litovitz et al. ^[1] estimated the battery removal time of 73 patients as follows: <4 hours 7 cases, < 8 hours 17 cases, < 12 hours 27 cases, < 24 hours 36 cases, < 2 days 42 cases, < 3 days 48 cases, < 1 week 60 cases, < 2 weeks 67 cases, < 6 weeks 72 cases, 1 case completely unknown. Only a very low percentage (23.3%) of patients removed their BBs without "delay" (G8 hours). However, the BB can cause serious tissue damage even within 2 hours. Reasons for the delay include limited access to endoscopists, referral to tertiary care institutions, or delayed anesthesia due to gastric tamponade may all cause complications^[15].

In view of the fact that the button battery causes serious complications in the upper digestive tract and the effective treatment time window is extremely short, and the shortcomings of easy slipping when the BB is grasped by the foreign body forceps under the endoscope, this study designed a simple, fast and effective magnetic retrieval system(MRS) for the BB of the upper digestive tract, we verified its feasibility by finite element analysis (FEA) simulation and removed BBs with MRS in Beagle model.

2.1 The magnetic retrieval system

In this study, a set of magnetic retrieval system(MRS) for removing the upper digestive tract BB was designed, including the magnetic retrieval device(MRD) and the external guide magnet. The MRD includes a cylindrical magnet made of neodymium iron boron (diameter 8mm, length 12mm), a polyvinyl chloride(PVC) tube (diameter 3mm, length 600mm), and a guide wire (Figure 1 A). The PVC tube is connected to the internal magnet. The front end of the magnet is a concave spherical structure, and the guide wire is inserted into the PVC tube to play a guiding role to prevent folding. The external guide magnet was φ50 mm × 80 mm, N40 NdFeB (Figure 1 B). Two types of button batteries were used in this study, 2412 and 2025 (Panasonic, 3V). The 24mm BB can be easily embedded in the physiological constrictifon of the beagle's esophagus, while the 20mm BB can reach the stomach through the beagle's esophagus under endoscope.

Mechanical properties of the magnetic retrieval device : We simulated the attraction force between the retrieved magnet and the BB in the horizontal and vertical states. The attraction force between the retrieved magnet and the BB in the horizontal and vertical states was also measured on a universal testing machine (SUNS technology, LTD, Shenzhen, China, model UTM6202). The results from this experiment were compared with those from the FEA simulation.

2.2 Study cohort

Place the BB (24mm) into the esophagus of 22 Beagle dogs under endoscope, and randomly divide them into two groups: magnet group and endoscope group. Under general anesthesia, use different methods to remove the bb in the esophagus. The endoscope group is clamped under the endoscope with foreign body forceps, and the magnet group is removed using the MRD. Also place the BB (20mm) into the stomach of 5 beagle dogs under endoscopic, Use the guide magnet attracts the insternal magnet and paramagnetic substance (button battery) in the stomach to the same target position and then attracts them together, the MRD attracts the BB to take out(Figure 2).

Institutional review board statement: The entire study was carried out in strict accordance with protocols approved by the Ethics Committee of the First Affiliated Hospital of Xi’an Jiaotong University (Permit Number: 2018-008).

Informed consent statement: This article does not contain any studies with human participants. For this type of study informed consent statement is not required.

2.3 Anesthesia

We used the intravenous injection of 3% sodium pentobarbital (1 mg/kg) to induce anesthesia and inhalation of isoflurane (1.5%-5.0%) to maintain intraoperative anesthesia.

2.4 Operation procedure

The button battery in the esophagus is magnetically retrieved: we record the entire operation process through continuous X-ray fluoroscopy and in vitro photography. Regardless of the upper, middle, and lower sections of the esophagus, the sterilized button battery MRD is placed into the esophagus through the mouth. The operation method is similar to the process of placing a gastric tube. When the internal magnetic meets the button battery in the esophagus, the sense of vibration generated during adsorption can be clearly felt by the operator through the guide wire, and then slowly pull the MRD at a uniform speed, the BB and the MRD can be removed smoothly（Figure 3 A-C）.

Remove the button battery in the esophagus under the endoscope: slowly enter the endoscopy through the mouth to determine the position of the BB, use a foreign body forceps to grasp the button battery, fix the foreign body forceps, the assistant assists withdrawing the endoscopy, and removed the BB (Figure 3 D-F).

The button battery in the stomach was magnetically retrieved: The MRS is placed into the stomach in advance. Due to the influence of the stomach space and food debris, the magnetic food debris device has poor operability in the stomach and cannot be easily attracted to the BB. According to the anatomical position of the stomach, the guide magnet is placed on the anterior abdominal wall in vitro. The external guide magnet attracts the BB and the internal magnet to move in the same direction and then attracts them together. Withdraw the external guide magnet, slowly pull the PVC tube, and remove the BB in the stomach (Figure 3 G-L). whether the BB is in the esophagus or stomach, after magnetic retrieval, endoscopy is performed in time, and the retrieved time, resistance and incidence of complications are also recorded.

Mechanical properties of the magnetic retrieval device :

According to the FEA simulation, as shown in Figure 4, the range of effective attractive force of the internal magnet of the MRD to the BBy is about 10 mm,When it exceeds 10 mm, the magnet has almost no attraction force to the BB. When the BB is in the horizontal state, the maximum attraction force of the magnet to the BB (diameter 20mm) is 11.96 N; when the BB is in the vertical state, the maximum attraction force of the magnet to the BB (diameter 20mm) is 1.37N. We also tested the attractive force of the internal magnet with a concave structure at the front end to the BB on the universal testing machine. The maximum attractive force in the horizontal state is 11.06±0.1N, and the maximum attractive force in the vertical state is 3.99±0.05N. It shows that through the concave design of the front end of the internal magnet, the attractive force of the magnet to the BB in the vertical state is obviously increased while not changing the attractive force of the magnet to the BB in the horizontal state. Characteristics of the study animals are shown in Table 1.

The button battery in the esophagus was retrieved:

The BB in the esophagus and stomach were all retrieved, No operation related complications occurred. The average weight of beagle dogs in the magnet group and endoscope group were 9.09 ± 1.14kg and 9.00 ± 1.94kg, P = 0.895, no significant difference; the average removal time of the BBs in the magnet group and endoscope group was 92.91 ± 82.47 s and 327.64 ± 270.63 s, P = 0.012, with significant difference. There were 4 cases of displacement in the endoscopic group during the operation, 2 cases of BBs in the endoscope group slipped off from the foreign body forceps, and There was no BB separated from the magnet in the magnet group, and the average resistance when the MRD retrieved the BB was 2.1 ± 1.02N. Although the magnet and the BB did not separate when the MRD retrieved the BB lodged in the esophagus, there was one case where the BB was stuck on the teeth and separated from the magnet in the oral cavity，removed the BB with forceps under direct view. In the endoscope group, two BBs slipped off from the foreign body forceps. They were both embedded in the second physiological stricture of the esophagus.When the foreign body forceps was clamped and removing, they were separated at the entrance of the esophagus(the first physiological stenosis).

It is worth noting that each of the 4 cases in the endoscopic group had at least one displacement when the BB was clamped by the foreign body forceps. One of them was a BB located near the cardia of the lower esophagus. Due to the reflux of local stomach contents, it covered the BB surface,the visual effect is poor. When the foreign body forceps were repeatedly clampped, the BB falls down into the stomach.After repeated dilution and extraction of stomach contents under the endoscope, the operator still cannot determine the location of the BB. This process takes 1080s. Finally, used the MRS to take out the BB, a total of 202s, which is only 1/5 of the former, specific information is shown in the fifth case of Table 2.

The button battery in the stomach was all retrieved:

A total of 5 beagle dogs used the MRS to retrieved the BBs in the stomach (Table 2). The median weight of the beagle dog was 9kg, and the median placement time for the MRD was 28s (21-32s). The median time for magnetic aggregation using a guide magnet is 87s (70-135s), the median retrieved time was 21s (19-35s), and the resistance during the retrieved was 1.98N (1.67-2.4N). Endoscopy was performed as soon as possible after removal, and no operation-related complications occurred.

Management of ingested button battery (BB) varies depending on its anatomic location and the potential risk of corrosive leakage which may cause severe tissue injury and subsequent perforation. There is agreement that if the BB is constantly lodged in the esophagus, immediate removal is necessary. With proper endoscopic technique, direct visualization of the mucosal condition of the esophageal and gastric lumens and concomitant prompt retrieval of the erroneously ingested BB may still be justified. Endoscopic foreing body retrieval is an established treatment for accidental ingestion, but mucus in the esophagus and the round slippery shape of the BB made it difficult. When the BB is picked up by a foreign body forceps, the force of the BB is often a point, not a surface contact, as shown in Figure 5. The BB rotates and slides off due to resistance in the physiological narrowing of the esophagus. This may be the reason for the BB slipping in this study. In a case report from China^[16] , a 2-year-old boy was referred to the otolaryngology department within 2 hours of ingesting the BB. Esophageal radiography showed a circular density in the upper part of his esophagus. Considering that general anesthesia requires fasting for 6 hours before routine surgery, it has been almost 8 hours since the BB was removed under endoscopy. Although the diagnosis is definite, the best time for treatment was delayed because of endoscopic preparation, referral, and delayed anesthesia. More unfortunately, BBs lodging in the esophagus can cause severe tissue damage even just within 2 hours^[6].

The MRS is easy to operate and easy to be grasped by clinicians, unlike endoscopic examination that requires a professional operator to complete. Not only shorten the removal time of the BB, but also get effective treatment in the first time of the patient, simplifying the treatment process. It is worth noting that subsequent endoscopic examination is still necessary to clarify the occurrence and development of complications , Related to further treatment and the patient's future prognosis.

The magnet relies on contactless magnetic force to find BBs in food and gastric juice. As early as 1982, Japanese scholar ByYasuoIto et al tried to removed under endoscope for a child patient who clearly diagnosed the BB in the stomach under general anesthesia^[17] , but the endoscopic removal was not successful because of the smooth shape of the food debris and BB in the stomach. A small ferrite magnet (5x5x15 mm) was tied to the tip of the polyethylene nasogastric tube and inserted into the stomach through the mouth with the aid of X-ray fluoroscopy. Manipulate the magnet for 15 minutes until it comes into contact with the BB. Then the same method was used to remove the gastric BBs of 15 children aged 8 months to 6 years without anesthesia. The front-end magnets use Al-Ni-Co magnets and rare earth cobalt magnets which are 2-3 times stronger than Al-Ni-Co alloy. The patients were operated under X-ray fluoroscopy for 5-20 minutes until the BB was attracted to the small magnet, and no related complications were found in all cases. But when the BB narrows physiologically in the esophagus, the BB usually gets off the magnet, especially in smaller patients. Although this method is easier and safer than endoscopy, under the X-ray fluoroscopy, depending on the operation of nasogastric tube to control the front-end magnet, the maneuverability is still poor, at the same time, there is a certain degree of radiation to patients and operators.

In 2007, Wen Jue Soong et al used an effective, safe and rapid technique of a modified magnetic endoscope (MME) to successfully retrieve the BBs^[18] . This technology requires a magnet to be fixed at the front end of the endoscope, and there is no ready-made equipment, so it needs to be made by the operator. In 2019, a case report from Japan used magnets to easily remove button batteries from the stomach under endoscope^[19] . Because the food residue in the stomach makes it difficult to find the BB, insert the endoscope into the stomach and close to the food residue, and with the aid of X-ray examination, insert the magnet into the food residue and move it close to the battery. The magnet can easily attract the BB, This process takes 5 minutes. In our study, the magnetic retrieval device made of NdFeB with stronger magnetic force, under the attraction of the external guide magnet, the button battery in the stomach can be quickly removed without the aid of endoscope and X-ray fluoroscopy, which reduces the requirements of environmental conditions when the button battery was retrieved, and greatly reducing the duration of the BB sustained injury.

The smaller diameter of the esophagus and the larger diameter of the button battery are the root causes of easy embedding. PUGMIRE et al.'s imaging study of 276 cases of BB intake showed that batteries at least 20mm in diameter were associated with esophageal impaction and higher grade of esophageal injury^[20] . In this study, a brand new BB larger than 20mm was selected, and a smaller beagle dog with a body weight below 10kg was selected. All Beagle dogs did not abstain from eating when establishing BB models, mainly simulating the uncertainty of children swallowing BBs, either on an empty stomach before or after a meal. For pediatric patients who swallowed the BB after a meal, general anesthesia is necessary during endoscopic removal. Delayed anesthesia due to gastric tamping, even returning the BB under the endoscope was very difficult. Magnetic retrieval system, similar to the insertion of a gastric tube omly, the BB can be removed at the first time.

It is necessary to improve the efficiency of diagnosis and treatment of BB intake and shorten the residence time of button batteries in the patients. Especially in primary and secondary medical institutions, it is necessary to reduce the chance of referral to tertiary medical institutions. The redesigned BB magnetic retrieval system has strong suction power, and the operation is similar to the process of gastric tube insertion. For cases where it was clearly diagnosed that the BB was embedded in the esophagus, it is possible to use a convenient MRD in the emergency department or pediatrics of any medical institution. For the BB that stays in the stomach for a long time, it may be considered to use a MRS to retrieve the BB in the stomach under the guide magnetic congregation.

Admittedly, there are several limitations that could be improved in a further study. First, although we tested the feasibility of the novel magnetic retrieval system with guide magnet by FEA simulation, mechanical measurements, and in vivo experiments, clinical trials with a lager sample size are required to further verify our novel system. Secondly,the shape of the internal magnet needs to be further improved, as well as the improvement of the external coating to improve the patient's medical experience. Finally, the diameter and hardness of polyethylene pipes need to be improved. We must choose polyethylene pipes of different diameters for patients of different ages. Next, we will further study the endoscopic magnetic retrieval system and animal experiment verification.

In summary, we designed a novel magnetic retrieval system in this study. The Magnetic navigation technology was introduced to the MRS for the first time. The MRS has a short magnetic retrieval time, is safe,cheapness and easy to operate, it can improve the treatment efficiency of foreign body in the upper digestive tract caused by the BB and reduce the incidence of complications and mortality. Overall, this MRS could be used for the retrieval of BB during children ingestion BBs.

Button batteries(BB)

European Society of Gastrointestinal Endoscopy (ESGE)

European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN)

Finite element analysis (FEA)

Modified magnetic endoscope (MME)

Magnetic retrieval device(MRD)

Magnetic retrieval system(MRS)

Polyvinyl chloride(PVC)

Ethics approval and consent to participate:

This study was reviewed and approved by the Institutional Animal Care and Use Committee of Xi’an Jiaotong University Health Science Center. All animals received humane care according to the criteria outlined in the “Guide for the Care and Use of Laboratory Animals” and the experimental procedures conformed to the Guideline for ethical review of animal welfare(GB/T 35892-2018) and were in accordance with ARRIVE guidelines. The experiments do not involve client-owned animals.

Consent for publication:

Not applicable

Availability of data and materials:

All data generated or analysed during this study are included in this published article.

Competing interests:

The authors declare that they have no competing interests.

Funding:

Key industrial chain projects of Shaanxi Province (2020ZDLSF04-08)

Authors' contributions:

Rongfeng Wang and Yiwen Lu are co-first authors of the article. All authors read and approved the final manuscript.

Acknowledgements:

Not applicable

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Table 1

Comparison of the retrieval of the button battery in the esophagus between the magnet group and the endoscope group

	Beagle weight(Kg)	Retrieve time(s)	Displacement	Slip off	Complication	Resistance (N)
Magnet group （n=11）	9.09±1.14	92.91±82.47	0/11	0/11	0	2.1±1.02
endoscope group（n=11）	9.00±1.94	327.64±270.63	4/11	2/11	0	-
P value	0.895	0.012	-	-	-	-

Note: The size of the internal magnet is 8 * 10mm, the diameter of the button battery is 24mm

Table 2

The basic characteristics and operation process of using the magnetic retrieval system to retrieved the button battery in the stomach

Number	Beagle weight(Kg)	Placement time (s)	Magnetic aggregation time (s)	Retrival time(s)	Resistance (N)	Complication
1	9	30	100	21	1.98	No
2	9	28	87	24	2.4	No
3	9	25	76	20	1.67	No
4	8	21	70	19	1.93	No
5	8	32	135	35	2.31	No

Note: The size of the internal magnet is 8 * 10mm; the diameter of the 1-4 button battery is 20mm, and the diameter of the 5th button battery is 24mm.

No competing interests reported.

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A novel magnetic retrieval system for button battery in upper gastrointestinal

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Abstract

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1. Background

2. Materials And Method

3. Results

4. Discussion

Conclusion

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