Magnamosis II: Magnetic compression anastomosis for minimally invasive gastrojejunostomy and jejunojejunostomy

Endoscopic application of magnetic compression anastomosis: a review

Magnetic compression anastomosis (MCA) is a new method that provides sutureless passage construction for tubular organs. Due to the high recurrence rate of conventional endoscopic treatment and the high morbidity and mortality of surgical procedures, the MCA technique shows promise. The aim of this review is to comprehensively examine the literature related to the use of MCA in different gastrointestinal diseases over the past few years, categorizing them according to the anastomotic site and describing in detail the various methods of magnet delivery and the clinical outcomes of MCA. MCA is an innovative technique, and its use represents an advancement in the field of minimally invasive interventions. Comparison studies have shown that the anastomosis formed by MCA is comparable to or better than surgical sutures in terms of general appearance and histology. Although most of the current research has involved animal studies or studies with small populations, the safety and feasibility of MCA have been preliminarily demonstrated. Large prospective studies involving populations are still needed to guarantee the security of MCA. For technologies that have been initially used in clinical settings, effective measures should also be implemented to identify, even prevent, complications. Furthermore, specific commercial magnets must be created and optimized in this emerging area.

Magnets in action: role of interventional radiologists in magnetic compression anastomosis procedures

Obstructions encountered in biliary, gastrointestinal, and urinary tracts are increasing in number due to successful percutaneous and endoscopic organ-saving procedures. Although functional recovery is established to an extent, failure of traversing an obstruction may end up necessitating invasive surgical procedures. Multidisciplinary collaboration may traverse the limitations of each individual approach, therefore creating the perfect intervention for the patient. Magnetic compression anastomosis is a minimally invasive procedure that can provide a great outcome in select cases with biliary, gastrointestinal, or urinary tract obstructions. CRITICAL RELEVANCE STATEMENT: In this article, various applications of magnetic compression anastomosis are reviewed with illustrative cases of esophageal, biliary, colonic, and urinary obstructions that cannot be traversed with a wire. This method will expand the spectrum of interventions performed in the IR unit. KEY POINTS: Magnets can enable wire access beyond an impassable obstruction. Magnets can create anatomical and non-anatomical anastomosis at an occlusion. Magnetic compression anastomosis is a minimally invasive procedure that can provide great outcomes.

Clinical diagnostic advances in intestinal anastomotic techniques: Hand suturing, stapling, and compression devices

The development of intestinal anastomosis techniques, including hand suturing, stapling, and compression anastomoses, has been a significant advancement in surgical practice. These methods aim to prevent leakage and minimize tissue fibrosis, which can lead to stricture formation. The healing process involves various phases: hemostasis and inflammation, proliferation, and remodeling. Mechanical staplers and sutures can cause inflammation and fibrosis due to the release of profibrotic chemokines. Compression anastomosis devices, including those made of nickel-titanium alloy, offer a minimally invasive option for various surgical challenges and have shown safety and efficacy. However, despite advancements, anastomotic techniques are evaluated based on leakage risk, with complications being a primary concern. Newer devices like Magnamosis use magnetic rings for compression anastomosis, demonstrating greater strength and patency compared to stapling. Magnetic technology is also being explored for other medical treatments. While there are promising results, particularly in animal models, the real-world application in humans is limited, and further research is needed to assess their safety and practicality.

Feasibility experiment of a novel deformable self-assembled magnetic anastomosis ring (DSAMAR) for gastrointestinal anastomosis through a natural orifice

Although the application of magnetic compression anastomosis is becoming increasingly widespread, the magnets used in earlier studies were mostly in the shape of a whole ring. Hence, a deformable self-assembled magnetic anastomosis ring (DSAMAR) was designed in this study for gastrointestinal anastomosis. Furthermore, its feasibility was studied using a beagle model. The designed DSAMAR comprised 10 trapezoidal magnetic units. Twelve beagles were used as animal models, and DSAMARs were inserted into the stomach and colon through the mouth and anus, respectively, via endoscopy to achieve gastrocolic magnamosis. Surgical time, number of failed deformations, survival rate of the animals, and the time of magnet discharge were documented. A month later, specimens of the anastomosis were obtained and observed with the naked eye as well as microscopically. In the gastrocolic anastomosis of the 12 beagles, the procedure took 65-120 min. Although a deformation failure occurred during the operation in one of the beagles, it was successful after repositioning. The anastomosis was formed after the magnet fell off 12-18 days after the operation. Naked eye and microscopic observations revealed that the anastomotic specimens obtained 1 month later were well-formed, smooth, and flat. DSAMAR is thus feasible for gastrointestinal anastomosis under full endoscopy via the natural orifice.

Influence of different magnetic forces on the effect of colonic anastomosis in rats

BACKGROUND

Despite much work having been conducted on magnetic compression anastomosis (MCA) in the digestive tract, there are no reports on the influence of magnetic force on the anastomosis.

AIM

To investigate the effect of different magnetic force magnets on the MCA of the digestive tract.

METHODS

Two groups of magnets of the same sizes but different magnetic forces were designed and produced. A total of 24 Sprague-Dawley rats were randomly assigned into two groups (powerful magnet group and common magnet group), with 12 rats in each group. Two types of magnets were used to complete the colonic side-to-side anastomosis of the rats. The operation time and magnet discharge time were recorded. The anastomotic specimens were obtained 4 wk after the operation and then the burst pressure and diameter of the anastomosis were measured, and the anastomosis was observed via the naked eye and subjected to histological examination.

RESULTS

The magnetic forces of the powerful and common magnet groups at zero distance were 8.26 N and 4.10 N, respectively. The colonic side-to-side anastomosis was completed in all 24 rats, and the operation success rate and postoperative survival rate were 100%. No significant difference was noted in the operation time between the two groups. The magnet discharge time of the powerful magnet group was slightly longer than that of the common magnet group, but the difference was not statistically significant (P = 0.513). Furthermore, there was no statistical difference in the burst pressure (P = 0.266) or diameter of magnetic anastomosis (P = 0.095) between the two groups. The gross specimens of the two groups showed good anastomotic healing, and histological observation indicated good mucosal continuity without differences on healing.

CONCLUSION

In the rat colonic side-to-side MCA model, both the powerful magnet with 8.26 N and the common magnet with 4.10 N showed no significant impact on the anastomosis establishment process or its effect.

Lessons Learned From the First-In-Human Compassionate Use of Connect-EA™ in Ten Patients With Esophageal Atresia

INTRODUCTION

Delayed primary repair of esophageal atresia in patients with high-risk physiologic and anatomic comorbidities remains a daunting challenge with an increased risk for peri-operative morbidity and mortality via conventional repair. The Connect-EA device facilitates the endoscopic creation of a secure esophageal anastomosis. This follow-up study reports our long-term outcomes with the novel esophageal magnetic compression anastomosis (EMCA) Connect-EA device for EA repair, as well as lessons learned from the ten first-in-human cases. We propose an algorithm to maximize the advantages of the device for EA repair.

METHODS

Under compassionate use approval, from June 2019 to December 2022, ten patients with prohibitive surgical or medical risk factors underwent attempted EMCA with this device. All patients underwent prior gastrostomy, tracheoesophageal fistula ligation (if necessary), and demonstrated pouch apposition prior to EMCA.

RESULTS

Successful device deployment and EMCA formation were achieved in nine patients (90%). Mean time to anastomosis formation was 8 days (range 5-14) and the device was retrieved endoscopically in five (56%) cases. At median follow-up of 22 months (range 4-45), seven patients (78%) are tolerating oral nutrition. Balloon dilations (median 4, range 1-11) were performed either prophylactically for radiographic asymptomatic anastomotic narrowing (n = 7, 78%) or to treat clinically-significant anastomotic narrowing (n = 2, 22%) with no ongoing dilations at 3-month follow up post-repair.

CONCLUSION

EMCA with the Connect-EA device is a safe and feasible minimally-invasive alterative for EA repair in high-risk surgical patients. Promising post-operative outcomes warrant further Phase I investigation.

LEVEL OF EVIDENCE

IV, Case series of novel operative technique without comparison group.

Evaluation of a Magnetic Compression Anastomosis for Jejunoileal Partial Diversion in Rhesus Macaques

PURPOSE

Metabolic surgery remains underutilized for treating type 2 diabetes, as less invasive alternative interventions with improved risk profiles are needed. We conducted a pilot study to evaluate the feasibility of a novel magnetic compression device to create a patent limited caliber side-to-side jejunoileal partial diversion in a nonhuman primate model.

MATERIALS AND METHODS

Using an established nonhuman primate model of diet-induced insulin resistance, a magnetic compression device was used to create a side-to-side jejunoileal anastomosis. Primary outcomes evaluated feasibility (e.g., device mating and anastomosis patency) and safety (e.g., device-related complications). Secondary outcomes evaluated the device's ability to produce metabolic changes associated with jejunoileal partial diversion (e.g., homeostatic model assessment of insulin resistance [HOMA-IR] and body weight).

RESULTS

Device mating, spontaneous detachment, and excretion occurred in all animals (n = 5). There were no device-related adverse events. Upon completion of the study, ex vivo anastomoses were widely patent with healthy mucosa and no evidence of stricture. At 6 weeks post-device placement, HOMA-IR improved to below baseline values (p < 0.05). Total weight also decreased in a linear fashion (R2 = 0.97) with total weight loss at 6 weeks post-device placement of 14.4% (p < 0.05).

CONCLUSION

The use of this novel magnetic compression device to create a limited caliber side-to-side jejunoileal anastomosis is safe and likely feasible in a nonhuman primate model. The observed glucoregulatory and metabolic effects of a partial jejunoileal bypass with this device warrant further investigation to validate the long-term glucometabolic impact of this approach.

Magnetic compression anastomosis for sigmoid stenosis treatment: A case report

BACKGROUND

Endoscopic balloon dilation is a minimally invasive treatment for colorectal stenosis. Magnetic compression anastomosis can be applied against gastrointestinal anastomosis. When combined with endoscopy, it offers a unique approach to the recanalization of colorectal stenosis.

CASE SUMMARY

We have reported here the case of a 53-year-old female patient who underwent a descending colostomy due to sigmoid obstruction. Postoperative fistula restoration was not possible in her due to sigmoid stenosis. Accordingly, endoscopic-assisted magnetic compression anastomosis for sigmoid stenosis was performed, and the sigmoid stenosis was recanalized 15 d after the surgery. Subsequently, a reduction colostomy was successfully performed after 10 d.

CONCLUSION

This case report proposes a novel minimally invasive treatment approach for colorectal stenosis.

Beyond the gut: spectrum of magnetic surgery devices

Since the 1970s, magnetic force has been used to augment modern surgical techniques with the aims of minimizing surgical trauma and optimizing minimally-invasive systems. The majority of current clinical applications for magnetic surgery are largely centered around gastrointestinal uses-such as gastrointestinal or bilioenteric anastomosis creation, stricturoplasty, sphincter augmentation, and the guidance of nasoenteric feeding tubes. However, as the field of magnetic surgery continues to advance, the development and clinical implementation of magnetic devices has expanded to treat a variety of non-gastrointestinal disorders including musculoskeletal (pectus excavatum, scoliosis), respiratory (obstructive sleep apnea), cardiovascular (coronary artery stenosis, end-stage renal disease), and genitourinary (stricture, nephrolithiasis) conditions. The purpose of this review is to discuss the current state of innovative magnetic surgical devices under clinical investigation or commercially available for the treatment of non-gastrointestinal disorders.

The Evolving Use of Magnets in Surgery: Biomedical Considerations and a Review of Their Current Applications

The novel use of magnetic force to optimize modern surgical techniques originated in the 1970s. Since then, magnets have been utilized as an adjunct or alternative to a wide array of existing surgical procedures, ranging from gastrointestinal to vascular surgery. As the use of magnets in surgery continues to grow, the body of knowledge on magnetic surgical devices from preclinical development to clinical implementation has expanded significantly; however, the current magnetic surgical devices can be organized based on their core function: serving as a guidance system, creating a new connection, recreating a physiologic function, or utilization of an internal–external paired magnet system. The purpose of this article is to discuss the biomedical considerations during magnetic device development and review the current surgical applications of magnetic devices.

Endoscopic magnetic compression stricturoplasty for congenital esophageal stenosis: A case report

BACKGROUND

Congenital esophageal stenosis (CES) is a rare malformation of the digestive tract. Endoscopic dilation and thoracotomy have been the main treatments for CES. However, there is no well-defined management protocol. Magnetic compression stricturoplasty (MCS) has been used in refractory esophageal stricture in children after esophageal atresia.

CASE SUMMARY

We describe the first case of MCS for CES in one female child patient. The child (aged 3 years and 1 mo) was admitted due to frequent vomiting and choking after eating complementary food since 7 mo old. Esophagography and gastroendoscopy showed that there was stenosis in the lower esophagus, suggesting a diagnosis of CES. The patient did not receive any treatment for esophageal stricture including surgery or endoscopic dilation procedures before MCS. MCS procedure was smoothly conducted without complications. At 24 mo after MCS, durable esophageal patency without dysphagia was achieved.

CONCLUSION

MCS may serve as an alternative and efficient method for patients with CES.

Novel Device for Endoluminal Esophageal Atresia Repair: First-in-Human Experience

Thoracoscopic esophageal atresia (EA) repair affords many benefits to the patient; however, intracorporeal suturing of the anastomosis is technically challenging. Esophageal magnetic compression anastomosis (EMCA) is a compelling option for endoluminal EA repair, but available EMCA devices have prohibitive rates of recalcitrant stricture. Connect-EA is a new endoluminal EMCA device system that employs 2 magnetic anchors with a unique mating geometry designed to reliably create a robust anastomosis and decrease rates of leak and stricture. We describe our first-in-human experience with this novel endoluminal device for staged EA repair in 3 patients (Gross type A, B, and C) at high risk for conventional surgical repair. First, the esophageal pouches were approximated thoracoscopically. After acute tension subsided, the device anchors were endoscopically placed in the esophageal pouches and mated. Anchors were spontaneously excreted in 2 cases. Endoscopic repositioning and retrieval of the anchors were required in 1 patient because of narrowed esophageal anatomy. There were no perioperative complications. Patients were managed for 14 to 18 months. The strictures that developed in the patients were membranous and responded well to dilation alone, resolving after 4 to 5 outpatient dilations. Gastrostomies were closed between 6 and 11 months and all patients are tolerating full oral nutrition. Early experience with this new endoluminal EMCA device system is highly favorable. The device offers considerable benefit over conventional handsewn esophageal anastomosis and anastomotic outcomes are superior to available EMCA devices.

Physical Bases, Indications, and Results of the Use of Magnets in Digestive Surgery: A Narrative Review

Background: The use of magnetic devices in digestive surgery has been a matter of debate in recent years. The aim of this review was to describe the physical bases, indications, and results of the use of magnets in digestive surgery. Methods: A review of the literature was performed using Scopus, PubMed, ScienceDirect, and SciELO databases considering as inclusion criteria all articles published since 2007 to date, describing the physical basis of magnetic assisted surgery and those that describe the surgical procedure, including case reports, as well as, articles on humans and experimental animals. Results: Sixty-four studies were included, 15 detailing aspects on the physical basis and 49 about indications and results. Magnets are currently used to perform fixed traction, mobilizing structures, and anastomosis in humans and experimental animals. Conclusions: The use of magnets in digestive surgery has shown good results, and no complications arising from their use have been reported. However, more prospective and randomized studies that compare magnetic surgery and conventional techniques are needed.

Sutureless Duodeno-Ileal Anastomosis with Self-Assembling Magnets: Safety and Feasibility of a Novel Metabolic Procedure

BACKGROUND

Less invasive and safer anastomotic techniques are desirable. We aimed to determine technical feasibility and safety of sutureless duodeno-ileal side-to-side anastomosis in obese patients using self-assembling magnets.

METHODS

This was an open-label, prospective, and single-arm study including obese patients (BMI 30-50 kg/m²) with type II diabetes. The ileal magnet was deployed laparoscopically, and the duodenal magnet was deployed endoscopically. Both magnets were coupled under laparoscopic and fluoroscopic guidance. The primary endpoints were technical feasibility and safety. The secondary endpoints were patency of the anastomosis, HbA1c reduction, and weight loss 12 months after the procedure.

RESULTS

A total of 8 patients were enrolled in the study; median age was 51.5 years (range: 34-65), and median BMI was 38.8 kg/m² (range: 35-47.9). The mean procedural duration was 63.5 min (range: 41-95). No intraoperative complications were recorded, and no major postoperative morbidity related to the procedure occurred. Magnets were expelled at a median of 29.5 days after the procedure with no associated complications. Upper endoscopy at 12 months confirmed patent anastomoses with healthy-appearing mucosa in all patients. HbA1c reduced below 7.0% in 6 out of 8 (75%) patients, and greater than 5% of total body weight loss was observed in 7 out of 8 (87.5%) patients at 12 months.

CONCLUSIONS

Sutureless duodeno-ileal side-to-side anastomosis using self-assembling magnets is feasible and safe in obese patients, and a dual-path enteral diversion with large-caliber and durable anastomosis can be achieved.

Endoscopic gastrointestinal anastomosis: a review of established techniques

Technologic advancements in the field of therapeutic endoscopy have led to the development of minimally invasive techniques to create GI anastomosis without requiring surgery. Examples of the potential clinical applications include bypassing malignant and benign gastric outlet obstruction, providing access to the pancreatobiliary tree in those who have undergone Roux-en-Y gastric bypass, and relieving pancreatobiliary symptoms in afferent loop syndrome. Endoscopic GI anastomosis is less invasive and less expensive than surgical approaches, result in improved outcomes, and therefore are more appealing to patients and providers. The aim of this review is to present the evolution of luminal endoscopic gastroenteric and enteroenteric anastomosis dating back to the first compression devices and to describe the clinical techniques being used today, such as magnets, natural orifice transluminal endoscopic surgery, and EUS-guided techniques. Through continued innovation, endoscopic interventions will rise to the forefront of the therapeutic arsenal available for patients requiring GI anastomosis.

New Technique for Magnetic Compression Anastomosis Without Incision for Gastrointestinal Obstruction

BACKGROUND

Magnetic compression anastomosis (MCA) is a novel technique of anastomosis similar to that with surgery, but in a minimally invasive manner. Few reports are available on the utility and feasibility of MCA for gastrointestinal anastomosis without requiring general anesthesia in humans, owing to the difficulty of delivering magnets. We evaluated the safety, efficacy, and feasibility of MCA in gastrointestinal obstruction without requiring general anesthesia.

STUDY DESIGN

In this retrospective single-center study, patients who underwent MCA from January 2013 to October 2019 were included. Adult patients with gastrointestinal obstruction or stenosis, irrespective of the underlying disease, with severe comorbidities, complicated abdominal surgical history, or postoperative complications, and who were unable to tolerate surgery, were eligible for inclusion. Two magnets were delivered by a combination of endoscopic and fluoroscopic procedures and placed in the lumen of the organ to be anastomosed. The main outcome was the technical success of MCA.

RESULTS

Fourteen patients underwent MCA, and the technical success of MCA was achieved in 100% of the cases. The mean procedural time, duration for anastomosis formation, and postoperative hospital stay were 44 minutes, 13 days, and 36 days, respectively. Two patients underwent anastomotic restenosis, and 1 patient had an anastomotic perforation due to balloon dilatation to prevent restenosis. The mean follow-up period was 34 months.

CONCLUSIONS

MCA without general anesthesia for gastrointestinal anastomosis is safe, useful, and feasible. MCA can be a valuable alternative to surgery in gastrointestinal obstruction.

Preliminary study of a control algorithm for radio-frequency-induced intestinal tissue fusion

Purpose: A control algorithm for radio-frequency-induced intestinal tissue fusion was developed to explore the effects of different control parameters on intestinal tissue fusion.Materials and methods: Radio-frequency-induced fusion was performed on ex vivo small intestine tissue. The effect on the fusion was observed by changing the control parameters (power, interval time, and terminal impedance) in the algorithm. The quality of fusion was evaluated using the burst pressure and thermal damage measurement. Histological evaluation was used to assess the fusion quality indirectly.Results: A maximum burst pressure of 8.460 ± 0.2674 KPa was acquired when the power was set to 100 W, the interval time was set to 2000 ms, and the terminal impedance was set to 50 Ω. Moreover, the thermal damage range increased with an increase in power but decreased with an increase in the interval time and terminal impedance. Furthermore, the thermal damage range and temperature were presumably related.Conclusions: For an ex vivo small intestine tissue, the appropriate control parameters could be set when the power was approximately 100 W, the interval time was approximately 2000 ms, and the terminal impedance was approximately 50 Ω. This study could provide a basis for the selection of control parameters for intestinal tissue fusion.

Endoscopic Magnetic Compression Anastomosis For Small Bowel Bypass in a High Operative Risk Setting

The endoscopic enteroenteral bypass could revolutionize the treatment of small bowel obstruction (SBO) in inoperable patients. We describe the technique of endoscopic delivery of a magnetic compression anastomosis device and the creation of an enteroenteral anastomosis in a patient with recurrent acute on chronic SBOs and prohibitively high operative risk. In this novel procedure, a magnetic compression anastomosis device is delivered on either side of the obstruction using a hybrid endoscopic/fluorographic technique, effectively bypassing the obstruction and relieving symptoms. The anastomosis was endoscopically evaluated at regular intervals postprocedure. By 7 days, healthy villi were visible through the mated magnetic rings. By 10 days, the anastomosis was widely patent. The rings passed through the ileostomy and were evacuated, and the patient's symptoms completely resolved. The anastomosis remained widely patent at 1 year. In summary, this case demonstrates the benefit of magnetic compression anastomosis in a patient with SBO and high operative risk.

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 Gastrojejunostomy for Superior Mesenteric Artery Syndrome Using Magnetic Compression Anastomosis

An 89-year-old woman who was bedridden suffered repeated vomiting due to superior mesenteric artery syndrome (SMAS). We performed gastrojejunostomy via the magnetic compression anastomosis (MCA) technique because her situation was not improved by conservative therapy and because the operative risk was high. We prepared two neodymium magnets: a flat plate-shaped magnet (15 × 3 mm) and a ring-shaped magnet of the same size. The ring-shaped magnet which passed through a guidewire was pushed to the duodenum by an endoscope over the guidewire. The duodenal stricture was balloon-dilated in front of the magnet, and the magnet was pushed all together beyond the stricture and placed at the duodenojejunal junction. Subsequently, the flat plate-shaped magnet was delivered endoscopically to the stomach using a biopsy forceps. The magnets were attracted towards each other transmurally after one more flat plate-shaped magnet was added to the gastric-side magnet. Completion of gastrojejunostomy was confirmed while retrieving the magnets 10 days after starting compression. She has been asymptomatic for 1 month since anastomosis. Endoscopic gastrojejunostomy using MCA was an effective, low-invasive treatment for SMAS.

Magnetic Anastomosis Rings to Create Portacaval Shunt in a Canine Model of Portal Hypertension

PURPOSE

This study evaluated a novel magnetic compression technique (magnamosis) for creating a portacaval shunt in a canine model of portal hypertension, relative to traditional manual suture.

METHODS

Portal hypertension was induced in 18 dogs by partial ligation of the portal vein (baseline). Six weeks later, extrahepatic portacaval shunt implantation was performed with either magnetic anastomosis rings, or traditional manual suture (n = 9, each). The two groups were compared for operative time, portal vein pressure, and serum biochemical indices. Twenty-four weeks post-implantation, the established anastomoses were evaluated by color Doppler imaging, venography, and gross and microscopic histological examinations.

RESULTS

Anastomotic leakage did not occur in either group. The operative time to complete the anastomosis for magnamosis (4.12 ± 1.04 min) was significantly less than that needed for manual suture (24.47 ± 4.89 min, P < 0.01). The portal vein pressure in the magnamosis group was more stable than that in the manual suture group. The blood ammonia level at the end of the 24-week post-implantation observation period was significantly lower in the magnamosis group than in the manual suture group. Gross and microscopic histological examinations revealed that better smoothness and continuity of the vascular intima had been achieved via magnamosis than with manual suture.

CONCLUSION

Magnamosis was superior to manual suture for the creation of a portacaval shunt in this canine model of portal hypertension.

Experience of Endoscopic Jejunojejunostomy for Anastomotic Obstruction After Subtotal Gastrectomy Using Magnetic Compression Anastomosis

Magnetic compression anastomosis (MCA) was developed as a low-invasive treatment for gastro-enteric or entero-enteric obstruction. A 72-year-old man underwent subtotal gastrectomy with Billroth II reconstruction for early gastric cancer. After the operation, he suffered from repeated aspiration pneumonia due to anastomotic obstruction caused by jejunal kinking at the efferent loop of anastomosis. We therefore performed jejunojejunostomy via the MCA technique, as his situation was not improved despite conservative therapy and he had a high reoperative risk. We prepared two flat plate-shaped neodymium magnets (15 × 3 mm) each with a small hole, and a nylon thread was passed through each hole. Each magnet was then delivered endoscopically to the anal side of the jejunal kinking, subsequently to the anastomosis, using biopsy forceps. The two magnets immediately became attracted towards each other transmurally. Oozing hemorrhage with clot at the mated magnets was observed 10 days after starting the compression. After retrieving the magnets, we confirmed the completion of jejunojejunostomy and then successfully achieved hemostasis of the anastomotic hemorrhage using argon plasma coagulation. The widely patent anastomosis was confirmed endoscopically 1 month after canalization; and he has been asymptomatic and able to eat a normal diet ever since. Endoscopic MCA is an effective, low-invasive treatment for anastomotic obstruction after subtotal gastrectomy. A standardized, safer procedure should be established for general use in the clinical setting.

Optimized force range of magnetic compression anastomosis in dog intestinal tissue

BACKGROUND

Magnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats.

METHODS

Magnets with different magnetic force groups (2.06, 3.21, 6.27, 13.3 and 19.2 N) were implanted into each dog to form intestinal tissue side-to-side anastomoses. Five dogs were euthanized on each of postoperative day 1, day 3, and day 7. Anastomoses were then harvested and compared with respect to postoperative complications, histology and tear-resistance load capacity (TRLC).

RESULTS

The TRLC of anastomotic tissue formed by magnets with different magnetic forces differed markedly, but with the tissue growth, the TRLC differences between groups were decreased. Histology of anastomotic tissue showed that, in the initial stage, the anastomoses compressed by 2.06-N magnets did not form effectively, while the leakage appeared in the anastomoses compressed by 19.2-N magnets, in the rest groups, with magnetic force increasing, severity of ischemia and necrosis of compressed tissue increased and healing speed of anastomotic tissue improved. In the late stage, the influence of magnetic force for anastomotic tissue was gradually diminished.

CONCLUSIONS

The magnetic force applied on the magnetic compression anastomats affects the necrosis speed of compressed tissue and the healing speed of anastomotic tissue. The optimal compressive force range for intestinal compression anastomosis is 6.27 N to 13.3 N, and the actual optimal compression pressure is 79.8 kPa - 169 kPa.

LEVEL OF EVIDENCE

Magnetic compression anastomosis (MCA) is a commonly used anastomosis method. MCA was widely used in tissues repair, gastroenterostomy, choledochoenterostomy, and so on. It is safer and more effective than stapler and manual surgical suturing. However, there are few detailed studies on the biomechanical characteristics and tissue transformation mechanisms of the anastomosis process. In this research, taking intestinal tissue as research object, we need to determine an optimal compressive force range to provide a biomechanical reference for the design of anastomats.

Novel magnetic compression technique for establishment of a canine model of tracheoesophageal fistula

BACKGROUND

Clinically, tracheoesophageal fistula (TEF) is lack of effective surgical strategies. One reason is due to the lack of appropriate animal models of acquired TEF, which is usually complex and difficult. Recently, the magnetic compression technique has been applied for digestive tract anastomosis or vascular anastomosis in animals. In this study, an animal model of TEF in dogs was developed by using the magnetic compression technique, hoping to provide a new method for mimicking TEF.

AIM

To establish a TEF model in dogs by using the magnetic compression technique.

METHODS

Six male beagles were used as models with two Nd-Fe-B permanent magnets for TEF. The parent magnet and the daughter magnet were placed in the cervical esophagus and trachea, respectively. The anterior wall of the esophagus and the posterior wall of the trachea were compressed when the two magnets coupled. After 4-6 d, the necrotic tissue between the two magnets fell off and the parent and daughter magnets disengaged from the target location, leaving a fistula. Gastroscopy/bronchoscopy, upper gastrointestinal contrast study, and histological analysis were performed.

RESULTS

The establishment of the TEF model in all six beagles was successful. The average time of magnet placement was 4.33 ± 1.11 min (range, 3-7 min). Mean time for the magnets to disengage from the target location was 4.67 ± 0.75 d (range, 4-6 d). TEFs were observed by gastroscopy/bronchoscopy and esophageal angiography. The gross anatomical structure of the esophagus and the trachea was in good condition. There was no esophageal mucosa or pseudostratified ciliated columnar epithelium at the site of the fistula according to histological analysis.

CONCLUSION

It is simple, feasible, and minimally invasive to use the magnetic compression technique for the establishment of the TEF model in dogs.

Further Development of Magnetic Compression for Gastrojejunostomy in Rabbits

BACKGROUND

Technical improvement of gastrojejunostomy is critical in bariatric and metabolic surgery. In this study, a novel magnetic compression approach for gastrojejunostomy was evaluated.

MATERIALS AND METHODS

Both cylindrical and rectangular magnets were used in rabbits, and the magnets were named according to their location. All the magnets were perorally introduced into the stomach. The position of the jejunal magnet was controlled by a connecting line. When the jejunal magnet spontaneously entered the jejunum, the gastric magnet was introduced into the stomach. An extracorporeal magnet was used to guide these two magnets together, and the magnet pair was left to create a side-to-side anastomosis. The state of the animals and extrusion time of the magnets were observed. The anastomoses were evaluated by burst pressure and histology.

RESULTS

Gastrojejunostomy was successfully established in all animals. Cylindrical and rectangular magnets spontaneously entered the jejunum through the pylorus within 2.4 ± 0.5 and 6.0 ± 0.8 d, respectively (P < 0.01). The cylindrical and rectangular magnet pairs fell off within 15.3 ± 0.8 and 11.9 ± 1.1 d, respectively (P < 0.01). The burst pressures were statistically similar between the two types of magnets (P > 0.05). Histological examination showed sealed anastomoses with mild inflammation of the mucosa and fibrosis within the submucosa.

CONCLUSIONS

The feasibility and efficacy of establishing gastrojejunostomy by guidewire introduction of magnets, which were guided together with an extracorporeal magnet, were confirmed in rabbits. In humans, with the clinical use of this procedure, surgery would be greatly simplified.

Magnetic compression anastomosis for the treatment of benign biliary strictures: a clinical study from China

BACKGROUND

Magnetic compression anastomosis (MCA) is a revolutionary minimally invasive method to perform choledochocholedochostomy in patients with benign biliary stricture (BBS). We conducted MCA for the treatment of severe BBS that could not be treated by conventional methods.

PATIENTS AND METHODS

Patients with BBSs that could not be treated using conventional treatments were included. All patients underwent percutaneous transhepatic biliary drainage (PTBD) before MCA, and underwent cholangiography via simultaneous PTBD and endoscopic retrograde cholangiopancreatography (ERCP). The MCA device consisted of a parent and a daughter magnet. The daughter magnet was delivered via the PTBD route to the proximal end of the obstruction, and the parent magnet was delivered via ERCP to the distal end of the obstruction. After recanalization, the MCA device was removed, and biliary stenting (or PTBD) was performed for at least 6 months.

RESULTS

Of the 9 patients (age 49 ± 12.9 years), 6 had undergone orthotopic liver transplantation. MCA was successful in all 9 patients. The stricture length was 3 ± 1.7 mm, and recanalization occurred after 16.3 ± 13.2 days. Multiple plastic stents (4 patients), fully covered self-expandable metallic stents (4 patients), or PTBD (1 patient) was used after recanalization. Two mild adverse events occurred (cholangitis, 1 patient; biliary bleeding, 1 patient), but were resolved with conservative treatment. Stents were retrieved after > 6 months, and no stenosis occurred during 2-66 months of stent-free follow-up.

CONCLUSION

The MCA technique is a revolutionary method for choledochocholedochostomy in patients with severe BBS unresponsive to conventional procedures.

Biomechanical and Performance Evaluation of Magnetic Elliptical-Ring Compressive Anastomoses

BACKGROUND

After magnetic compressive anastomosis, anastomat passage through the narrow channels of the digestive tract is difficult owing to the device's large volume. Such passage can lead to mechanical damage to the digestive tract or anastomat's unstable excretion time. This article presents a new magnetic compressive anastomotic approach.

METHODS

A magnetic elliptical-ring compressive anastomat was designed and evaluated for placement and passage in vitro. Nine young adult dogs underwent laparotomy with intestinal tissue side-to-side anastomosis. Four different groups of magnetic compressive anastomats of two different magnetic force levels (20 N or 30 N) and shapes (round or elliptical) were implanted into each dog simultaneously. Three dogs were euthanized on each of postoperative day 1, day 4, and day 7. Anastomoses were then compared with respect to histology and tensile fracture force.

RESULTS

The magnetic elliptical-ring compressive anastomat was functional but produced less obstruction compared to its round counterpart during passage through the esophagus and intestine. Nine dogs underwent successful surgery and harvesting of 30 total anastomoses. Histology of anastomotic tissue showed that, along the newly formed tunnel connecting the two sides of anastomotic tissues, compressed tissues became thinner and fell off, and initial anastomoses formed on the seventh postoperative day. There were large differences in tensile fracture force among the anastomoses formed by magnets with different magnetic forces of the same structure. However, the magnetic compressive anastomat structure did not affect anastomotic repair during magnetic compression anastomosis.

CONCLUSIONS

The magnetic elliptical-ring compressive anastomat is an efficient anastomotic device that can be used easily and with good passage. The device has good biomechanical properties and can be used with endoscopy to reduce operative time.

Magnetic compression anastomosis (magnamosis) in a porcine esophagus: Proof of concept for potential application in esophageal atresia

BACKGROUND

Magnetic compression anastomosis (magnamosis) is the process of forming a sutureless anastomosis of the gastrointestinal tract using two magnetic Harrison rings. It has been shown to be effective in stomach, small bowel and colon, but has not been implemented in the esophagus. A pure esophageal atresia porcine model was developed to test the concept.

METHODS

Five pigs weighing between 35 and 65 kg were used. In all pigs, a percutaneous endoscopic gastrostomy (PEG) tube was placed, and a right thoracotomy was performed. Esophageal atresia was simulated by transecting the esophagus with a cutting stapler, and magnets were placed endoscopically to approximate the two ends of the esophagus. In the first pig, the tissue within the magnetic ring was excised endoscopically to achieve immediate patency. In the second pig, approximation of the blind esophageal ends was reinforced with 3-4 externally-placed sutures but immediate patency was not performed. In the last three pigs, both external suture reinforcement and immediate patency were performed. The pigs survived for 10-14 days and received nutrition through PEG tube. At necropsy, an esophagram was performed, the specimen was explanted and a leak test was performed.

RESULTS

The first pig died in the early postoperative period from a leak owing to separation of the magnets. The second pig died from aspiration before the anastomosis formed. The last three pigs survived until the study endpoint. The third pig had a contained leak owing to the staple line being placed between the magnets; this was not clinically significant. The last two pigs had well-formed anastomoses. Burst tests showed no leak when injecting saline up to 30 mmHg.

CONCLUSION

Magnamosis is technically feasible for esophagoesophageal anastomoses. A survival model for pure esophageal atresia was developed and refined in pigs. Further work in this area may lead to clinical use in humans.

Use of magnets in gastrointestinal surgery

BACKGROUND

Laparoscopic and endoscopic surgery has undergone vast progress during the last 2 decades, translating into improved patient outcomes. A prime example of this development is the use of magnetic devices in gastrointestinal surgery. Magnetic devices have been developed and implemented for both laparoscopic and endoscopic surgery, providing alternatives for retraction, anchoring, and compression among other critical surgical steps. The purpose of this review is to explore the use of magnetic devices in gastrointestinal surgery, and describe different magnetic technologies, current applications, and future directions.

METHODS

IRB approval and written consent were not required. In this review of the existing literature, we offer a critical examination at the use of magnets for gastrointestinal surgery currently described. We show the experiences done to date, the benefits in laparoscopic and endoscopic surgery, and additional future implications.

RESULTS

Magnetic devices have been tested in the field of gastrointestinal surgery, both in the contexts of animal and human experimentation. Magnets have been mainly used for retraction, anchoring, mobilization, and anastomosis.

CONCLUSION

Research into the use of magnets in gastrointestinal surgery offers promising results. The integration of these technologies in minimally invasive surgery provides benefits in various procedures. However, more research is needed to continually evaluate their impact and implementation into surgical practice.

The use of neodymium magnets in healthcare and their effects on health

The strong magnetic field properties of magnets have led to their use in many modern technologies, as well as in the fields of medicine and dentistry. Neodymium magnets are a powerful type of magnet that has been the subject of recent research. This review provides a brief explanation of the definition, history, and characteristics of rare earth magnets. In addition, a broad overview of results obtained in studies performed to date on the effects of magnets, and neodymium magnets in particular, on body systems, tissues, organs, diseases, and treatment is provided. Though they are used in the health sector in various diagnostic devices and as therapeutic tools, there is some potential for harmful effects, as well as the risk of accident. The research is still insufficient; however, neodymium magnets appear to hold great promise for both diagnostic and therapeutic purposes.

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

Magnetic Compression Anastomosis (Magnamosis) for Functional Undiversion of Ileostomy in Pediatric Patients

INTRODUCTION

Magnamosis forms a compression anastomosis using self-aligning magnetic Harrison rings. The device has been approved by the Food and Drug Administration for first-in-human testing and has been applied in adults for intestinal anastomosis during urologic reconstructions. We now report the first cases of magnamosis to functionally undivert the fecal stream from a previously created loop ileostomy in pediatric patients.

MATERIALS AND METHODS

Case 1: A 4-year-old male underwent a diverting loop ileostomy for malignant bowel obstruction. The obstruction gradually resolved with chemotherapy, and persistently high stomal output and malnutrition prompted undiversion. Case 2: A 16-year-old female with iloecolonic polyposis underwent ileoproctectomy with J pouch and diverting ileostomy. The magnamosis functional undiversion (FUN) technique involves introducing a Harrison ring through each stomal limb under general anesthesia with X-ray guidance. Magnets are each tied with sutures that exit the stoma and are then tied to each other externally. The device is removed when patency is detected.

RESULTS

The introduction procedure took less than 20 minutes and there were no complications. Enteral feeding was initiated 24 and 6 hours postoperatively, and distal passage of stool occurred by the fourth and fifth days, respectively. Magnets were removed 14 and 15 days postoperatively, without evidence of leak.

CONCLUSION

We conclude that the magnamosis undiversion procedure is a safe, minimally invasive way to gradually refunctionalize the excluded distal bowel after previous diverting ostomy.

Magnetic Compression Stricturoplasty For Treatment of Refractory Esophageal Strictures in Children: Technique and Lessons Learned

INTRODUCTION

Esophageal stricture is the most common complication following repair of esophageal atresia (EA). In general, these strictures are successfully managed using endoscopic techniques including bougie and balloon dilation, stenting, and chemotherapeutic agent application. If these techniques are unsuccessful, patients require segmental esophageal resection and reanastomosis or esophageal replacement. Magnetic compression anastomosis has been described in children. Herein we report our experience with magnetic compression stricturoplasty to treat refractory strictures after EA repair.

METHODS

We reviewed our experience using magnets to treat refractory strictures in 2 patients. Both patients failed multiple standard interventions. Because of near complete esophageal obstruction, both patients were candidates for esophageal replacement or segmental resection/anastamosis. In both patients, we applied neodymium-iron-boron magnets using fluoroscopic and endoscopic guidance.

RESULTS

The magnets were successfully positioned in both cases. Magnets were left in place for 7 and 10 days allowing for gradual compression stricturoplasty/anastamosis. Upon removal of the magnets, recanalization was visualized endoscopically and self-expanding stents were placed. There were no leaks or significant early complications. By 31 months post-magnetic stricturoplasty, both patients achieved durable esophageal patency without dysphagia.

CONCLUSION

Magnetic stricturoplasty was successful at establishing early patency of the esophagus in 2 patients with recalcitrant EA strictures. Fundamental knowledge of magnetism was critical in configuring magnet arrays for surgery. In both cases, early follow-up is promising. Further follow-up will define the long-term success of this technique.

Treatment of completely obstructed benign biliary strictures with magnetic compression anastomosis: follow-up results after recanalization

BACKGROUND AND AIMS

Although nonsurgical methods produce high clinical success rates in the treatment of benign biliary stricture (BBS), conventional methods are not always successful in cases of severe biliary stricture or complete obstruction. Therefore, the efficacy of magnetic compression anastomosis (MCA) for treatment of refractory BBS was evaluated in a single-center, nonrandomized study.

METHODS

MCA was performed in patients with BBS that was not resolved by conventional endoscopic or percutaneous treatments. One magnet was delivered through the percutaneous transhepatic biliary drainage tract, and the other advanced through 1 of 3 different routes. After magnet approximation and recanalization, an internal drainage catheter was placed for 6 months.

RESULTS

This study followed 39 patients who underwent MCA after the development of postoperative or traumatic strictures. Recanalization was achieved successfully in 35 patients. There was an acceptable procedure-related adverse event of mild cholangitis in 1 patient and no procedure-related mortalities. The average elapsed time from magnet approximation to removal was 57.4 days (range, 13-182 days), and the mean follow-up period after recanalization was 41.9 months (range, 7.1-73.4 months). Restenosis after MCA recurred in 1 patient, and partial restenosis occurred in another patient, but recanalization in these patients was successful using a guidewire via the percutaneous and endoscopic tracts.

CONCLUSIONS

MCA represents an alternative nonsurgical recanalization method for BBSs that cannot be treated by conventional methods. The rate of stricture recurrence after MCA was lower than that after conventional methods, likely because of the creation of a new fistula tract instead of dilation of a previous stricture.

Treatment of rectovaginal fistula by magnetic compression

INTRODUCTION AND HYPOTHESIS

Rectovaginal fistula (RVF) is an abnormal epithelium-lined connection between the rectum and vagina. The primary effective treatment is surgical repair, but recurrence remains a challenge. Magnetic compression anastomosis (MCA), an alternative to suturing, has been developed to generate an anastomosis between various hollow viscera. We hypothesized that the MCA approach could be used to treat RVF.

METHOD

We designed a novel MCA device for RVF treatment and evaluated the magnetic compression procedure in a RVF pig model in comparison with the traditional suturing procedure. Following satisfactory outcomes, we also applied the MCA procedure to a human patient with recurrent RVF. The MCA device was designed based on the anatomical characteristics of the pig vagina and previous literature. The pig RVF model were established surgically (n = 12), and compression and control groups were each treated. The data were analyzed by one-way analysis of variance.

RESULTS

qqExcept in one animal in each group, the RVF site was smooth and healing was complete. Histological analysis confirmed complete healing of the RVF with high histological continuity to neighboring tissues. The compression procedure applied to our patient with RVF was successful. The patient recovered quickly without complications, and RVF did not recur during a 15-month follow-up.

CONCLUSIONS

From this preliminary investigation, MCA using our novel device appears to be a safe, simple, and effective nonsurgical procedure for the treatment of RVF.

Repair of esophageal atresia with proximal fistula using endoscopic magnetic compression anastomosis (magnamosis) after staged lengthening

We describe the treatment of a patient with long-gap esophageal atresia with an upper pouch fistula, mircogastria and minimal distal esophageal remnant. After 4.5 months of feeding via gastrostomy, a proximal fistula was identified by bronchoscopy and a thoracoscopic modified Foker procedure was performed reducing the gap from approximately 7-5 cm over 2 weeks of traction. A second stage to ligate the fistula and suture approximate the proximal and distal esophagus resulted in a gap of 1.5 cm. IRB and FDA approval was then obtained for endoscopic placement of 10-French catheter mounted magnets in the proximal and distal pouches promoting a magnetic compression anastomosis (magnamosis). Magnetic coupling occurred at 4 days and after magnet removal at 13 days an esophagram demonstrated a 10 French channel without leak. Serial endoscopic balloon dilation has allowed drainage of swallowed secretions as the baby learns bottling behavior at home.

Endoscopic intestinal bypass creation by using self-assembling magnets in a porcine model

BACKGROUND AND AIMS

A purely endoluminal method of GI bypass would be desirable for the treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets that create large-caliber anastomoses (Incisionless Anastomosis System [IAS]). The aim of this study was to evaluate procedural characteristics of IAS deployment and long-term anastomotic integrity and patency.

METHODS

We performed a 3-month survival study of Yorkshire pigs (5 interventions, 3 controls). Intervention pigs underwent simultaneous enteroscopy/colonoscopy performed with the animals under intravenous sedation. The IAS magnets were deployed and coupled with reciprocal magnets under fluoroscopy. Every 3 to 6 days pigs underwent endoscopy until jejunocolonic anastomosis (dual-path bypass) creation and magnet expulsion. Necropsies and histological evaluation were performed. The primary endpoints were technical success; secondary endpoints of anastomosis integrity, patency, and histological characteristics were weight trends.

RESULTS

Under intravenous sedation, endoscopic bypass creation by using IAS magnets was successfully performed in 5 of 5 pigs (100%). Given porcine anatomy, the easiest dual-path bypass to create was between the proximal jejunum and colon. The mean procedure time was 14.7 minutes. Patent, leak-free anastomoses formed by day 4. All IAS magnets were expelled by day 12. All anastomoses were fully patent at 3 months with a mean diameter of 3.5 cm. The mean 3-month weight was 45 kg in bypass pigs and 78 kg in controls (P = .01). At necropsy, adhesions were absent. Histology showed full re-epithelialization across the anastomosis without fibrosis or inflammation.

CONCLUSION

Large-caliber, leak-free, foreign body-free endoscopic intestinal bypass by using IAS magnets can be safely and rapidly performed in the porcine by model using only intravenous sedation.

Inductive Sensing to Detect Tissue Thickness Between Magnets for Potential Application in Magnetic Compression Based Anastomosis

Magnetic compression based anastomoses use magnetic force to necrose tissue between two magnets to create an anastomosis. Nickel-plated neodymium–iron–boron magnets are used in our study. The compression pressure between the magnets depends on the distance between the magnets, which is determined by the thickness of the compressed tissue and depends on bowel wall thickness and elasticity. It is critical to know the distance between the magnets once the tissue is compressed because the magnets must be within a critical distance of each other in order to create enough compressive force to necrose the tissue. We have developed an inductance sensor to detect the distance (tissue thickness) between the two magnets after the surgeon has deployed them. Inductance sensing is a contact-less sensing method that enables precise short-range detection of conducting surfaces. The inductor coil mounted on one magnet detects the second magnet by measuring the change in inductance due to eddy current induced on the nickel-plated surface of the second magnet. The change in the inductance is proportional to the change in distance between the magnets. The sensor was first calibrated by using polycarbonate sheets to simulate the intestine tissue. We are able to detect up to 6 mm of spacing between the magnets. Pig intestine from Yorkshire pigs was used to characterize the sensor. We are able to distinguish up to five distinct layers of the intestine from the large intestine. This sensing mechanism can indicate the operating surgeon the exact thickness of the tissue compressed between the two magnets. The surgeon can thus be sure of formation of a clean anastomosis and avoid the likelihood of the magnets sliding away or uncoupling.

Minimally invasive entero-enteral dual-path bypass using self-assembling magnets

BACKGROUND

A minimally invasive method of entero-enteral bypass may be desirable for treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets which create large-caliber anastomoses (incisionless anastomosis system or IAS). The aim of this study was to assess (a) procedural characteristics of IAS deployment and (b) long-term integrity and patency of the resulting jejuno-ileal dual-path bypass.

METHODS

Endoscopic jejuno-ileal bypass creation using IAS magnets was performed in 8 Yorkshire pigs survived 3 months.

PROCEDURE

The jejunal magnet was endoscopically deployed. However, the ileal magnet required surgical delivery given restraints of porcine anatomy. A 5-mm enterotomy was created through which the ileal magnet was inserted using a modified laparoscopic delivery tool. Magnets were manually coupled. Pigs underwent serial endoscopies for anastomosis assessment. Three-month necropsies were performed, followed by pressure testing of anastomoses and histological analysis.

RESULTS

Jejuno-ileal bypass creation using self-assembling IAS magnets was successful in all 8 pigs (100 %). Patent, leak-free bypasses formed in all animals by day 10. All IAS magnets were expelled by day 12. Anastomoses were widely patent at 3 months, with mean maximal diameter of 30 mm. At necropsy, adhesions were minimal. Pressure testing confirmed superior integrity of anastomotic tissue. Histology showed full epithelialization across the anastomosis with no evidence of submucosal fibrosis or inflammation.

CONCLUSIONS

Entero-enteral bypass using self-assembling IAS magnets is safe and technically feasible in the porcine model. IAS magnets can be rapidly delivered endoscopically or through a modified laparoscopic device. Expulsion of fused magnets avoids retention of prosthetic material. Anastomoses are widely patent and fully re-epithelialized. Three-month pressure testing reveals anastomotic tissue to be as robust as native tissue, while necropsy and histology suggests minimal/absent tissue inflammation. In human anatomy, a fully endoscopic jejuno-ileal bypass using IAS magnets may be feasible.

Magnetic compression anastomosis for treatment of benign biliary stricture

Endoscopic and percutaneous procedures have shown high success rates when used to treat benign biliary stricture. However, cases in which a guidewire cannot be passed through a refractory stricture or a complete obstruction are difficult to treat using conventional methods. Magnetic compression anastomosis (MCA) has emerged as a non-surgical alternative avoiding operational mortality and morbidity. The feasibility and safety of MCA have been experimentally and clinically verified in cases of biliobiliary and bilioenteric anastomosis. However, no pre-MCA assessment modality capable of predicting outcomes is as yet available, and no universally effective magnet delivery method has as yet been established, rendering it difficult to identify patients for whom MCA is appropriate. Various experimental studies seeking to overcome these limitations are underway. Such work will improve our in-depth understanding of MCA, which has been trialed in various fields. Upon further development, MCA may become a ground-breaking option for treatment of benign strictures that are difficult to resolve using conventional methods, and MCA may be expected to be minimally traumatic and highly effective. The aim of the present study was to discuss the current status of MCA and the direction of MCA development by reviewing clinical and experimental MCA data.

Magnetic ring anastomosis of suprahepatic vena cava: novel technique for liver transplantation in rat

To improve the technique of suprahepatic vena cava (SHVC) reconstruction in rat OLT, novel magnetic rings were designed and manufactured to facilitate reconstruction of SHVC and shorten the anhepatic time. One-hundred and twenty adult male Wistar rats were randomly divided into two groups: rings group (n = 30), using magnetic rings for SHVC reconstruction; suture group (n = 30), 7/0 prolene suture was used for SHVC running anastomosis as control. Cuff techniques were used for portal vein and infrahepatic vena cava reconstruction as Kamada and Calne described. The bile duct was reconnected with a stent. The hepatic re-arterialization was omitted. In the rings group, the SHVC reconstruction took 0.91 ± 0.24 (mean ± SD) min; the anhepatic phase and the recipient operation time were 5.63 ± 0.65 min and 36.02 ± 8.02 min, respectively. In suture group, the anastomotic time of SHVC was 10.40 ± 2.11 min; the anhepatic phase and the recipient operation time were 17.76 ± 2.51 and 49.38 ± 12.06 min, respectively, and there was statistically significant difference between the two groups. The ALT levels reached peak at 24 h post-OLT (186.2 ± 32.5 IU/l) and restored to normal level at 96 h gradually. In the rings group, 29 of 30 rats survived at day 7 and 28 of 30 rats survived at day 30. In contrast, only 25 of 30 recipients in suture group remained alive at day 7 and 22 of 30 remained alive at day 30 (P < 0.05). Better anastomotic healing was founded in rings group by pathology and scanning electron microscope. The magnetic rings technique provides a novel, simple method for SHVC reconstruction of OLT in rat. It significantly shortens anhepatic phase, while the success rate of the operation is satisfactory.

Magnamosis: a novel technique for the management of rectal atresia

We report a case of rectal atresia treated using magnets to create a rectal anastomosis. This minimally invasive technique is straightforward and effective for the treatment of rectal atresia in children.

Magnamosis combined with endoscopy: A new endoscopic technique in digestive surgery

Conventional hand-sewn technique is the basic method for anastomosis in the gastrointestinal tract. However, with the rapid development of minimally invasive surgery and the spread of fast track surgery, hand-sewn technique cannot satisfy the requirements of modern surgery. The common goal that the majority of surgeons seek to achieve has changed: to reduce surgical invasion and operative time as minimally as possible, on the premise that therapeutic and anastomotic effects can be guaranteed. Therefore, after more than 30 years of exploration and development, magnamosis as a novel anastomosis technique shows its significant superiority in anastomosis or recanalization in the gastrointestinal tract. Furthermore, the combination of magnamosis and endoscopy may transform part of the surgical procedures into endoscopic procedures. This review aims to elucidate the application and future development of magnamosis combined with endoscopy in anastomosis or recanalization in the gastrointestinal tract.

Magnetic gastrointestinal anastomosis in pediatric patients

BACKGROUND/PURPOSE

To describe 17 patients who underwent magnetic, non-surgical gastrointestinal (GI) anastomoses.

METHODS

Patients with GI obstruction, stenosis, or atresia were treated with image-guided and/or endoscopically placed discoid magnet pairs or catheter-based bullet-shaped magnet pairs.

RESULTS

Anastomosis was achieved in 7 days in an 11-year-old with gastric outlet obstruction due to metastatic colon cancer. Anastomosis was achieved in 8 and 10 days in 2 patients (age 2.0 years and 3.4 years) who had rectocolonic stenosis. Re-anastomosis was achieved in an average of 6 days (range 3 to 7 days) in 5 patients (age 6 months to 5.9 years) with severe recurrent postsurgical esophageal stenosis refractory to dilatation. Primary esophageal anastomosis was achieved in an average of 4.2 days (range 3 to 6 days) in 9 patients with esophageal atresia (Type A or Type C surgically converted to Type A) with a gap length of 4 cm or less. The average age of these esophageal atresia patients was 3 months (range 23 days to 5 months).

CONCLUSION

Minimally invasive magnet placement was feasible and achieved anastomosis in all patients.