A novel endoesophageal magnetic device to prevent gastroesophageal reflux

Problems with repairing gut sphincters malfunctions

Correcting a gut sphincter malfunction is a difficult problem. Because each sphincter has two opposite functions, that of closure and opening, repairing one there is a risk of damaging the other. Indeed, widening a narrow sphincter, such as lower esophageal sphincter (LES) and anal sphincter, may cause gastroesophageal reflux and fecal incontinence, respectively, whereas narrowing a wide sphincter, may cause a difficult transit. All the corrective treatments for difficult or retrograde transit concerning LES and anal sphincter with their unwanted consequences have been analyzed and discussed. To overcome the drawbacks of sphincter surgical repairs, researchers have devised devices capable of closing and opening the gut lumen, named artificial sphincters (ASs). Their function is based on various mechanisms, e.g., hydraulic, magnetic, mechanical etc, operating through many complicated components, such as plastic cuffs, balloons, micropumps, micromotors, connecting tubes and wires, electromechanical clamps, rechargeable batteries, magnetic devices, elastic bands, etc. Unfortunately, these structures may facilitate the onset of infections and induce a local fibrotic reaction, which may cause device malfunctioning, whereas the compression of the gut wall to occlude the lumen may give rise to ischemia with erosions and other lesions. Some ASs are already being used in clinical practice, despite their considerable limits, while others are still at the research stage. In view of the adverse events of the ASs mentioned above, we considered applying bioengineering methods to analyze and resolve biomechanical and biological interaction problems with the aim to conceive and build efficient and safe biomimetic ASs.

Magnetic challenge against gastroesophageal reflux

Almost 15 years have passed since the first paper on the possibility of using magnets to prevent gastro-esophageal reflux (GER) was published and so it is time to assess the results obtained with the first magnetic device available on the market, the Linx magnetic sphincter augmentation (MSA) and to consider what other options are forthcoming. MSA demonstrated an anti-reflux activity similar to that of Nissen fundoplication, considered the "gold standard" surgical treatment for GER disease, and caused less gas-bloating and a better ability to allow vomiting and belching. However, unlike Nissen fundoplication, this magnetic device is burdened by complications, which are roughly similar to those of the non-magnetic anti-reflux Angelchik prosthesis, that, after considerable use in the eighties, was shelved due to these complications. It is interesting to note that some of these complications show the same pathophysiological mechanism in both devices. The upcoming new magnetic devices should avoid these complications, as their anti-reflux magnetic mechanism is completely different. The experiments in animals regarding these new magnetic appliances were examined, remarking their advantages and drawbacks, but the way to apply them in surgical practice is long and difficult, although worthy, as they represent the future of magnetic surgery.

Constant magnetic field in treating congenital esophageal and anorectal malformation: a review

Background

Congenital esophageal and anorectal malformation are common in neonates. Refractory esophageal anastomotic stricture and abnormal defecation after surgical correction in infants are challenging surgical problems. Magnetic compression anastomosis (MCA) using mated magnets with their interposed compressed tissue may result in serosa-to-serosa apposition.

Data sources

A literature search was performed to establish an algorithm for these accidents by the authors to identify relevant articles published from 1977 to 2019 in Google, Medline, ISI Web of Knowledge Ovid, CNKI and library document delivery, using search terms “magnetics”, “esophageal malformation”, “anorectal” and “perforation”. A total of 24 literatures were collected.

Results

Magnamosis is technically feasible for alimentary tract anastomoses in pediatric patients. The magnets are most commonly made of neodymium–iron–boron and samarium–cobalt alloys, which have been employed to create solid anastomosis for long-gap esophageal atresia and refractory esophageal stricture without thoracotomy in children in recent years. Furthermore, magnamosis can be used for the functional undiversion of ileostomy. In anorectal malformations with favorable anatomy, this procedure may avoid an operative repair such as posterior sagittal reconstruction.

Conclusion

Translumenal anastomosis of digestive tract using the MCA is a reliable, minimally invasive and feasible method to treat congenital esophageal and anorectal malformation.

Endoscopic applications of magnets for the treatment of gastrointestinal diseases

Endoscopic treatment of gastrointestinal diseases has developed rapidly in recent years, due to its minimally invasive nature. One of the main contributing factors for this progress is the improvement of endoscopic instruments, which are essential for facilitating safe and effective endoscopic interventions. However, the slow learning curve required in the implementation of many advanced endoscopic procedures using standard devices is associated with a high risk of complications. Other routine procedures may also be complicated by unexpected difficulties. Based on the ferromagnetic properties of many objects, both internal and external magnetic devices have been developed and applied for multiple endoscopic interventions. The applications of magnets, mainly including compression, anchoring and traction, facilitate many difficult procedures and make it feasible to operate procedures that were previously impossible. Other novel endoscopic applications, such as magnetic nanoparticles, are also under development. In this article, we reviewed published studies of endoscopic applications of magnets for the treatment of gastrointestinal diseases such as precancerous lesions and cancer, obstruction, stricture, congenital and acquired malformations, motility disorders, and ingestion of foreign bodies. Since several endoscopic applications of magnets may also be relevant to surgery, we included them in this review.

Endoscopic magnet placement into subadventitial tunnels for augmenting the lower esophageal sphincter using submucosal endoscopy: ex vivo and in vivo study in a porcine model (with video)

BACKGROUND AND AIMS

Endolumenal therapies serve as a treatment option for GERD. This study aimed to determine if magnets could be placed endoscopically using the adventitial layer to create a subadventitial space near the esophagogastric junction to augment the lower esophageal sphincter using submucosal endoscopy.

METHODS

This study consisted of 2 phases, ex vivo and in vivo, with domestic pig esophagus. A long submucosal tunnel was made at the mid to lower esophagus. The muscularis propria was incised by a needle-knife within the submucosal tunnel. A subadventitial tunnel was made by biliary balloon catheter blunt dissection, and a magnet was deployed in the subadventitial space. The same maneuver was done within the opposing esophageal wall, with magnet placement in the opposing subadventitial space.

RESULTS

Submucosal tunnels and subadventitial tunnels were successful without perforation ex vivo in all attempts and in 9 of 10 cases, respectively. Magnets were deployed in the subadventitial space in 7 cases. Magnets connected and separated with atraumatic endoscope passage into the stomach and reconnected when the endoscope was withdrawn under fluoroscopy in 5 of 7 cases (71.4%). In vivo submucosal tunnels and subadventitial tunnels were successful in all 5 cases, and magnet augmentation was functionally active in 4 cases (80%).

CONCLUSION

Subadventitial tunnels were feasible and could represent a new working space for endoscopic treatment. Endoscopic placement of magnets within the subadventitial space may be an attractive alternative endolumenal therapy for GERD.

Magnetic Control of the Glottic Opening in an Ex Vivo Sheep Larynx Model: A Preliminary Study

OBJECTIVE/HYPOTHESIS

So far, a number of techniques have been described for the treatment of bilateral vocal fold paralysis. These techniques were reported to be successful in maintaining an adequate airway but also found to be associated with an increased risk of aspiration, dysphonia, and granulation tissue formation at the operation site. We aimed to investigate the effectiveness of a novel mucosa-sparing technique based on the generation of a magnetic field within the larynx for the tailored lateralization of the ipsilateral vocal fold.

STUDY DESIGN

This is an ex vivo experimental study.

METHODS

Twenty sheep larynges that were procured from the local slaughterhouse were used as a model. For each specimen, two neodymium (Nd) disc magnets with marked poles were used to create a unilateral attractive magnetic force at the glottic level. Following insertion of the magnets, the level of vocal fold lateralization was assessed under an operating microscope. The results were analyzed for their statistical significance.

RESULTS

Before the procedure, the mean value of the glottic openings of all the specimens was 4.985 mm. The postprocedure mean value was 5.640 mm. The mean amount of increase in the glottic openings after the procedure was 0.655 mm. This change was found to be statistically significant (P < 0.05).

CONCLUSIONS

A statistically significant increase in the cross-sectional area of the glottic region could be achieved. The mucosal integrity of the laryngeal airway was also preserved. The idea of "magnetic control of the glottic airway" is a novel concept but seems to be a promising option.