Magnamosis III: delivery of a magnetic compression anastomosis device using minimally invasive endoscopic techniques

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.

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.

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.

Magnetic Compression Anastomosis-Past Experience and Current Proposals for Further Development in Pediatric Minimally Invasive Surgery

Originating in the 1970s, magnetic compression anastomosis (MCA) has lately been revisited with a focus on minimal invasive surgery (MIS). The aim of this report is to reappraise our earlier experience with MCA with the intention of facilitating future MCA advancement. A retrospective review was conducted regarding preclinical experiments and clinical trials at a single institution from 1980 to 1995. The reviewed information was compiled and appraised to generate proposals for future MCA use. The experimental studies, including 250 MCA cases in gastrointestinal and urinary tract animal models, demonstrated the technical versatility of MCA as well as the superior biomechanical characteristics in comparison to hand-sewn anastomoses. Clinical trials encompassed 87 MCA procedures in 86 children, 2 to 10 years of age, involving the following techniques: non-operative esophageal recanalization (n = 15), non-operative ileostomy undiversion (n = 46), Swenson pull-through (n = 10), non-operative urethral recanalization (n = 5), and extravesical ureterocystoneostomy (n = 11). Clinical MCA was found to be successful in over 87% of cases. MCA limitations concerning anastomotic failure and scarring were thought to be mostly due to inadequate magnetic compression. Based on our historic experience, we propose further research on the technical aspects of MCA, along with the biological aspects of anastomotic tissue remodeling. Magnets should be designed and manufactured for a wide spectrum of pediatric surgical indications, particularly in combination with novel MIS techniques.

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.

Electromagnetic tool for the endoscopic creation of colon anastomoses-development and feasibility assessment of a novel anastomosis compression implant approach

BACKGROUND

Colorectal anastomoses are among the most commonly performed interventions in abdominal surgery, while associated patient trauma is still high. Most recent trends of endoscopic anastomosis devices integrate magnetic components to overcome the challenges of minimally invasive surgery. However, the mutual attraction between magnetic implant halves may increase the risk of inadvertently pinching healthy structures. Thus, we present a novel anastomosis device to improve system controllability and flexibility.

METHODS

A magnetic implant and an applicator with electromagnetic control units were developed. The interaction of magnetic implants with the electromagnets bears particular challenges with respect to the force-related dimensioning. Here, attraction forces must be overcome by the electromagnet actuation to detach the implant, while the attraction force between the implant halves must be sufficient to ensure a stable connection. Thus, respective forces were measured and the detachment process was reproducibly investigated. Patient hazards, associated with resistance-related heating of the coils were investigated.

RESULTS

Anastomosis formation was reproducibly successful for an implant, with an attraction force of 1.53 [Formula: see text], resulting in a compression pressure of [Formula: see text]. The implant was reproducibly detachable from the applicator at the anastomosis site. Coils heated up to a maximum temperature of [Formula: see text]. Furthermore, we were able to establish a neat reconnection of intestinal bowel endings using our implant.

DISCUSSION

As we achieved nearly equal compression forces with our implant as other magnetic anastomosis systems did (Magnamosis™: 1.48 N), we concluded that our approach provides sufficient holding strength to counteract the forces acting immediately postoperatively, which would eventually lead to an undesired slipping of the implant halves during the healing phase. Based on heat transfer investigations, preventive design specifications were derived, revealing that the wall thickness of a polymeric isolation is determined rather by stability considerations, than by heat shielding requirements.

Systematic Review and Meta-Analysis on Colorectal Anastomotic Techniques

Purpose

Anastomosis creation after resective gastrointestinal surgery is a crucial task. The present review examines the techniques and implants currently available for anastomosis creation and analyses to which extent they already address our clinical needs, with a special focus on their potential to enable further trauma minimization in visceral surgery.

Methods

A multi-database research was conducted in MEDLINE, Scopus, and Cochrane Library. Comparative controlled and uncontrolled clinical trials dealing with anastomosis creation techniques in the intestinal tract in both German and English were included and statistically significant differences in postoperative complication incidences were assessed using the RevMan5.4 Review Manager (Cochrane Collaboration, Oxford, UK).

Results

All methods and implant types were analyzed and compared with respect to four dimensions, assessing the techniques’ current performances and further potentials for surgical trauma reduction. Postoperative outcome measures, such as leakage, stenosis, reoperation and mortality rates, as well as the tendency to cause bleeding, wound infections, abscesses, anastomotic hemorrhages, pulmonary embolisms, and fistulas were assessed, revealing the only statistically significant superiority of hand-suture over stapling anastomoses with respect to the occurrence of obstructions.

Conclusion

Based on the overall complication rates, it is concluded that none of the anastomosis systems addresses the demands of operative trauma minimization sufficiently yet. Major problems are furthermore either low standardization potentials due to dependence on the surgeons’ levels of experience, high force application requirements for the actual anastomosis creation, or large and rigid device designs interfering with flexibility demands and size restrictions of the body’s natural access routes. There is still a need for innovative technologies, especially with regard to enabling incisionless interventions.

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.

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.

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.

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.

A novel magnetic compression technique for small intestinal end-to-side anastomosis in rats

BACKGROUND

Magnetic compression technology is a safe and convenient digestive tract reconstruction technique in large animals. The purpose of this study was to verify the feasibility of using the micromagnetic ring for construction of small intestinal end-to-side anastomosis in rats.

METHODS

Thirty male Sprague-Dawley albino rats were randomly divided into two groups: a study group that underwent small intestinal anastomosis with micromagnetic ring and a control group that had hand-sewn anastomosis. The time to construct the anastomosis, survival rate and incidence of complications were compared between the two groups. The anastomotic segments in each group were harvested on day 28 after surgery and investigated.

RESULTS

The mean anastomosis construction time was significantly lower in the study group than the control group (6.80 ± 1.97 min vs. 16.13 ± 3.29 min, P < 0.05). The survival rate was significantly higher in the study group (93.3%, 14/15) than the control group (66.7%, 10/15; P < 0.05). The incidence of anastomotic leakage [0% (0/15) vs. 6.67% (1/15), P = 1.000] and obstruction [20% (3/15) vs. 13.33% (2/15), P = 0.330] was similar in the study group and control group. The mean burst pressure did not differ significantly between the magnetic compression and hand-sewn anastomosis. In the study group, alignment of the tissue layers was improved and the inflammatory reaction was milder.

CONCLUSION

Use of a micromagnetic ring for small intestinal end-to-side anastomosis in rats is safe and feasible.

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.

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.

Surgical Endoscopy Versus Endoscopic Surgery for Obesity

BACKGROUND

Obesity treatment options are of great interest worldwide with major developments in the past 20 years. From general surgery to natural orifice transluminal endoscopic surgery intervention nowadays, obesity surgical therapies have surely developed and are now offering a variety of possibilities.

AREAS OF UNCERTAINTY

Although surgery is the only proven approach for weight loss, a joint decision between the physician and patient is required before proceeding to such a procedure. With a lot of options available, the treatment should be individualized because the benefits of surgical intervention must be weighed against the surgical risks.

DATA SOURCES

Medline search to locate full-text articles and abstracts with obvious conclusions by using the keywords: obesity, surgical endoscopy, gastric bypass, bariatric surgery, and endoscopic surgery, alone and in various combinations. Additional relevant publications were also searched using the reference lists of the identified articles as a starting point.

RESULTS

Laparoscopic Roux-en-Y gastric bypass still is the most effective, less invasive, bariatric surgical intervention, although there are various complications encountered, such as postoperative hemorrhage (1.9%-4.4%), internal hernias, anastomotic strictures (2.9%-23%), marginal ulcerations (1%-16%), fistulas (1.5%-6%), weight gain, and nutritional deficiencies. However, the absence of parietal incisions, less pain, decreased risk of infection, and short hospital stay make room for endoscopic surgery as a possible valid option for obesity for both the doctors' and the patients' perspective.

CONCLUSIONS

The current tendency is to promote surgical treatment of obesity to a status of less invasive scars therefore promoting minimally invasive surgical techniques.

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.

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.

Exploiting gastrointestinal anatomy for organ classification in capsule endoscopy using locality preserving projections

Capsule Endoscopy is a technique designed to wirelessly image the small intestine within the gastrointestinal (GI) tract. Its main drawback is the vast amount of images it generates per patient, necessitating long screening sessions by the clinician. Previous studies have proposed to partially facilitate this process by automatically segmenting the GI tract into its constituent organs, thus identifying the region of interest. In this work, we propose to exploit the anatomical structure of the GI tract when carrying out dimensionality reduction on visual feature vectors that describe the capsule images. To this end, we suggest a novel adaptation of a technique called Locality Preserving Projections, and results show that this achieves an improved performance in organ classification and segmentation, at no additional computational or memory cost.

A novel spherical magnetic compression device for colorectal anastomosis in a Swine model

BACKGROUND

We designed a novel, spherical magnetic compression colorectal anastomosis device and established a swine model to assess the feasibility and safety, as well as advantages, of the device.

METHODS AND MATERIALS

Fifteen animals were divided into five groups (sacrificed on Days 3, 5 7, 9, and 14) with 3 in each group. In each group, a magnetic compression device was used in 2 animals (experimental animals), and a stapled device was used in 1 animal (control animal). Feeding status, bowel movements, the discharge time of the magnetic anastomosis device, burst pressure, and magnetic field strength were recorded. Gross anatomical and histological examinations were performed.

RESULTS

The average device discharge time was 7.5 days. The burst pressure increased over time for both the experimental and control animals. Both the gross anatomical and histological examinations suggested that the inflammatory reaction was milder. Healing occurred more quickly, and the incidence of complications was lower for the experimental animals than for the control animals.

CONCLUSIONS

The potential benefits of the spherical magnetic compression colorectal anastomosis device, relative to the stapled device, were in terms of effectiveness and complication incidence, which encourages us to further study its application in gastrointestinal anastomosis.

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.

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.

"Tie over ring" sutureless compression based gastrointestinal anastomotic method: experimental rat model

INTRODUCTION

Giving the ever-rising trend of pediatric minimally invasive surgery besides early neonatal surgical interventions, intestinal anastomosis turns out to be a time consuming stage due to several anatomical as well as technical difficulties. A perfect bowel anastomosis method should be easy, rapid, safe and reliable in creation of bowel continuity with minimal tissue damage. In this light, sutureless anastomotic methods have been introduced, using compression based anastomosis with biofragmentable rings or powerful magnets. Accordingly, this experimental animal model study has evaluated the result of an easy, rapid intestinal sutureless anastomotic technique via simple tying over an intraluminal ring, in comparison with conventional handsewn bowel anastomosis.

METHODOLOGY

Thirty Wistar-Albino male rats were enrolled and small bowel was transected via a midline laparotomy. A grooved plastic ring was inserted into the ileal lumen and both intestinal cutting ends were fixed over the ring with a simple tie in the first group. On the other hand, enteroenterostomy was performed by the conventional method of handsewn anastomosis in the second group. After 14 days, rats were sacrificed to evaluate for intraperitoneal adhesion and abscess formation in addition to other evidences of anastomotic leakage. Furthermore, the anastomotic site integrity, tensile strength and healing stage were assessed microscopically.

RESULTS

The mean operative time and intraoperative bleeding in the tie over ring group were significantly less than those in the handsewn anastomosis group. Anastomotic stricture was more common in the conventional anastomosis group while the anastomotic tensile strength was significantly higher in the tie over ring group. Histopathological healing parameters and final healing score were almost similar in both groups but mean inflammatory cell infiltration in handsewn anastomosis was significantly higher.

CONCLUSION

"Tie over ring" is a simple method of anastomosis that is feasible, fast, safe and functionally effective for bowel reconstruction in animal models that could be reconsidered in human bowel anastomosis.

Swallowed magnets and batteries: a dangerous but not unexpected attraction

An 18-month-old boy was witnessed swallowing a cluster of five magnetic toy balls. He was coincidentally noted on plain x-rays to have also recently swallowed a watch battery and a small screw. Initial outpatient management with serial review and x-rays was unsuccessful, and delayed inpatient surgical care by 9 days. Although the child never manifested features of systemic or gastrointestinal upset, emergency laparotomy confirmed a resultant jejunocolic fistula. This case demonstrates how clinical assessment of children who have swallowed magnets separately from each other can be falsely reassuring, and highlights the potential dangers of outpatient management. We recommend children who have swallowed separately >1 magnetic objects (or >1 objects capable of magnetic attraction) be managed as inpatients with active observation and timely foreign body removal.