New Technique for Magnetic Compression Anastomosis Without Incision for Gastrointestinal Obstruction

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.

Research progress on anatomy reconstruction of rat orthotopic liver transplantation

Rat orthotopic liver transplantation (ROLT) serves as an ideal animal model and has gained popularity in addressing complications and perioperative treatments related to clinical liver transplantation. Through extensive research on ROLT model construction, the conventional "two-cuff" method has gradually become established. However, traditional methods still present challenges including limited visual field during vascular suturing, vascular torsion, biliary tract injuries, and prolonged anhepatic periods. Consequently, this paper aims to review the latest advancements and various techniques in this field, providing a valuable reference for individuals interested in constructing ROLT models.

Clinical application of magnetic anchor technique in laparoscopic cholecystectomy: the first retrospective study in China

Background and objectives

Magnetic anchor technique (MAT) is frequently used in laparoscopic cholecystectomy. However, there are few reports on its clinical application in China. In this study, we retrospectively analyzed the clinical application of MAT in laparoscopic cholecystectomy in China.

Materials and methods

25 patients (4 males, 21 females) who underwent laparoscopic cholecystectomy assisted by MAT at the First Affiliated Hospital of Xi'an Jiaotong University were enrolled from November 2020 to March 2021. Their records were retrospectively analyzed. The magnetic anchor device was independently designed and developed by the authors and consisted of the anchor magnet and magnetic grasping apparatus. Surgical time, intraoperative blood loss, intraoperative accidents, operator experience, postoperative incision pain score, postoperative complications, and other indicators were evaluated and analyzed.

Results

All patients successfully underwent laparoscopic cholecystectomy, including 3 cases of MAT-assisted transumbilical single-port LC, 16 cases of MAT-assisted 2-port LC and 6 cases of conventional 3-port LC. The median operation time was 50 min (range 30-95 min); intraoperative bleeding was less than 30 ml. The median score of surgical incision on day 1 and 3 after the operation was 3 (range 1-4) and 1 (range 1-3), respectively. All patients had no intraoperative bile duct injury, vascular injury, postoperative bleeding, bile leakage, biliary stricture and other complications. No adverse events (such as injury to adjacent organs or failure of the magnetic anchor device) occurred either during or after the operation.

Conclusions

The MAT-assisted laparoscopic cholecystectomy appears to be safe, feasible and effective and exhibits unique assistance in transumbilical single-port laparoscopic cholecystectomy.

Endoscopic gastrointestinal bypass anastomosis using deformable self-assembled magnetic anastomosis rings (DSAMARs) in a pig model

BACKGROUND

To investigate the feasibility of a deformable self-assembled magnetic anastomosis ring (DSAMAR), designed and developed by us, for endoscopic gastrointestinal bypass anastomosis.

METHODS

Ten experimental pigs were used as model animals. The DSAMAR comprises 10 trapezoidal magnetic units, arranged in a straight line under the constraint of a guide wire. When the desired anastomosis site is reached under the guidance of an endoscope, the catheter pushes the magnetic unit along the guide wire. The linear DSAMAR can be assembled into a circular DSAMAR. Two DSAMARs were inserted, one at the end of the duodenum and the other into the stomach successively. They attracted each other and compressed the wall of the stomach and duodenum to establish gastrointestinal bypass anastomosis. The experimental pigs were euthanized 4 weeks after the operation, and the gastrointestinal bypass anastomosis specimens were obtained. The anastomosis formation was evaluated by the naked eye and histology.

RESULTS

Gastrointestinal bypass anastomosis with DSAMARs was successfully performed. The average operation time under an endoscope was 70.30 ± 19.05 min (range: 43-95 min). The DSAMARs were discharged through the anus 10-17 days after surgery. There were no complications such as gastrointestinal bleeding, perforation, anastomotic fistula, and gastrointestinal obstruction during and after the operation. Gastroscopy and gross specimen of the anastomosis showed a well-formed magnetic anastomosis. Histological observation showed good continuity of the serous membrane and the mucosa of magnetic anastomosis.

CONCLUSION

The DSAMAR is a safe and feasible device for fashioning gastrointestinal bypass anastomosis in this animal model.

Novel deformable self-assembled magnetic anastomosis ring for endoscopic treatment of colonic stenosis via natural orifice

BACKGROUND

Although endoscope-assisted magnetic compression anastomosis has already been reported for colonic anastomosis, there is no report on a single-approach operation using the natural orifice.

AIM

To design a deformable self-assembled magnetic anastomosis ring (DSAMAR) for colonic anastomosis for use in single-approach operation and evaluate its feasibility and safety through animal experiments.

METHODS

The animal model for colonic stenosis was prepared by partial colonic ligation in eight beagles. The magnetic compression anastomosis of their colonic stricture was performed by endoscopically assisted transanal implantation of the DSAMAR. The anastomotic specimen, obtained 2 wk after the operation, was observed by both the naked eye and a light microscope.

RESULTS

The DSAMAR was successfully inserted into the proximal end of colon stenosis through the anus. The DSAMAR of seven dogs was successfully transformed into rings, while that of the remaining dog was removed after the first deformation failed. The rings were successfully retransformed after optimization. All animals underwent colonic anastomosis using the DSAMAR. No device-related or procedure-related adverse events were observed. The colostomy specimens of the experimental dogs were obtained 2 wk after the operation. Both gross and histological observations showed good anastomotic healing.

CONCLUSION

The DSAMAR is a safe and feasible option for the treatment of colon stenosis. Its specific deformation and self-assembly capability maximize the applicability of the minimally invasive treatment.

First-in-Human Side-to-Side Magnetic Compression Duodeno-ileostomy with the Magnet Anastomosis System

PURPOSES

Classical gastrointestinal anastomoses are formed with sutures and/or metal staples, resulting in significant bleeding and leak rates. This study evaluated the feasibility and safety of the novel magnet anastomosis system (MS) to create a side-to-side duodeno-ileal (DI) diversion for weight loss and type 2 diabetes (T2D) resolution.

MATERIALS AND METHODS

Patients with severe obesity (body mass index (BMI) ≥ 35 kg/m2 with/without T2D (HbA1C ≥ 6.5%)) underwent the study procedure, a side-to-side MS DI diversion, with a standard sleeve gastrectomy (SG). A linear magnet was delivered by flexible endoscopy to a point 250 cm proximal to the ileocecal valve; a second magnet was positioned in the first part of the duodenum; the bowel segments containing magnets were apposed, initiating gradual anastomosis formation. Laparoscopic assistance was used to obtain bowel measurements, obviate tissue interposition, and close mesenteric defects.

RESULTS

Between November 22 and 26, 2021, 5 female patients (mean weight 117.6 ± 7.1 kg, BMI (kg/m2) 44.4 ± 2.2) underwent side-to-side MS DI + SG. All magnets were successfully placed, expelled without re-intervention, and formed patent durable anastomoses. Total weight loss at 12 months was 34.0 ± 1.4% (SEM); excess weight loss, 80.2 ± 6.6%; and BMI reduction, 15.1. Mean HbA1C (%) dropped from 6.8 ± 0.8 to 4.8 ± 0.2; and glucose (mg/dL), from 134.3 ± 17.9 to 87.3 ± 6.3 (mean reduction, 47.0 mg/dL). There was no anastomotic bleeding, leakage, obstruction, or infection and no mortality.

CONCLUSIONS

Creation of a side-to-side magnetic compression anastomosis to achieve duodeno-ileostomy diversion in adults with severe obesity was feasible and safe, achieved excellent weight loss, and resolved type 2 diabetes at 1-year follow-up.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT05322122.

Primary animal experiment to test the feasibility of a novel Y-Z magnetic hepatic portal blocking band

BACKGROUND

Hepatic portal blood flow occlusion is a common technique for reducing hepatic hemorrhage during hepatectomy. We designed a novel Y-Z magnetic hepatic portal blocking band (Y-Z MHPBB) based on the principle of magnetic compression technique.

AIM

To introduce the Y-Z MHPBB device and verify the feasibility of this device for hepatic portal blood flow occlusion in dogs.

METHODS

Ten beagles were randomly divided into the experimental group and control group. The operation time, intraoperative blood loss, the number of portal blood flow occlusions, the total time spent on adjusting the blocking band, and the average time spent on adjusting the blocking band were recorded. The surgeons evaluated the feasibility and flexibility of the two portal occlusion devices.

RESULTS

Laparoscopic hepatectomy was successfully performed in both the experimental group and control group. There was no statistical difference between the two groups in the operation time, intraoperative blood loss, and the number of hepatic portal blood flow occlusions. With respect to the total time spent on adjusting the blocking band and the average time spent on adjusting the blocking band, the experimental group showed significantly better outcomes than the control group, with a statistical difference (P < 0.05). The operators found that the Y-Z MHPBB was superior to the modified T-tube in terms of operational flexibility.

CONCLUSION

The Y-Z MHPBB seems to be an ingenious design, accurate blood flow occlusion effect, and good flexibility; and it can be used for hepatic portal blood flow occlusion during laparoscopic hepatectomy.

Side-to-side magnet anastomosis system duodeno-ileostomy with sleeve gastrectomy: early multi-center results

INTRODUCTION

Gastrointestinal anastomoses with classical sutures and/or metal staples have resulted in significant bleeding and leak rates. This multi-site study evaluated the feasibility, safety, and preliminary effectiveness of a novel linear magnetic compression anastomosis device, the Magnet System (MS), to form a side-to-side duodeno-ileostomy (DI) diversion for weight loss and type 2 diabetes (T2D) resolution.

METHODS

In patients with class II and III obesity (body mass index [BMI, kg/m²] ≥ 35.0- ≤ 50.0 with/without T2D [HbA1C > 6.5%]), two linear MS magnets were delivered endoscopically to the duodenum and ileum with laparoscopic assistance and aligned, initiating DI; sleeve gastrectomy (SG) was added. There were no bowel incisions or retained sutures/staples. Fused magnets were expelled naturally. Adverse events (AEs) were graded by Clavien-Dindo Classification (CDC).

RESULTS

Between November 22, 2021 and July 18, 2022, 24 patients (83.3% female, mean ± SEM weight 121.9 ± 3.3 kg, BMI 44.4 ± 0.8) in three centers underwent magnetic DI. Magnets were expelled at a median 48.5 days. Respective mean BMI, total weight loss, and excess weight loss at 6 months (n = 24): 32.0 ± 0.8, 28.1 ± 1.0%, and 66.2 ± 3.4%; at 12 months (n = 5), 29.3 ± 1.5, 34.0 ± 1.4%, and 80.2 ± 6.6%. Group mean respective mean HbA1_C and glucose levels dropped to 1.1 ± 0.4% and 24.8 ± 6.6 mg/dL (6 months); 2.0 ± 1.1% and 53.8 ± 6.3 mg/dL (12 months). There were 0 device-related AEs, 3 procedure-related serious AEs. No anastomotic bleeding, leakage, stricture, or mortality.

CONCLUSION

In a multi-center study, side-to-side Magnet System duodeno-ileostomy with SG in adults with class III obesity appeared feasible, safe, and effective for weight loss and T2D resolution in the short term.

Side-to-side duodeno-ileal magnetic compression anastomosis: design and feasibility of a novel device in a porcine model

BACKGROUND

Minimally invasive metabolic/bariatric surgery (MBS) may be further advanced by magnetic compression anastomosis (MCA) technology. The study aimed to develop a magnet sized to create a patent duodeno-ileostomy (DI) and verify its effectiveness in a porcine model.

METHODS

Developmental study phase: magnets with 4 different flange-offset dimensions were tested to identify a design that would successfully form a compression anastomosis. Verification phase: evaluation of the selected design's efficacy. In each 6-week phase (4 pigs/phase), one magnet was inserted laparoscopically in the jejunum, one placed gastroscopically in the duodenum. Magnets were aligned, gradually fused, formed an anastomosis, and then detached and were expelled. At necropsy, MCA sites and sutured enterotomy sites were collected and compared.

RESULTS

Developmental phase: the linear BC42 magnet with a 2.3-mm flange offset design was selected. Verification phase: in 4 swine magnets were mated at the target location, confirmed radiographically. Mean time to magnet detachment 16.0 days (12-22), to expulsion 24.5 days (17-33). MCA was achieved in all animals at time of sacrifice. Animals gained a mean 9.5 kg (3.9-11.8). Specimens revealed patent anastomoses of ≥ 20 mm with smooth mucosa and minimal inflammation and fibrosis compared to sutured enterotomies. One pig underwent corrective surgery for a mesenteric hernia without sequelae.

CONCLUSION

In a large-animal model, gross and histopathologic examination confirmed that the linear MCA device created a patent, well-vascularized, duodeno-ileal anastomosis. The novel MCA device may be appropriate for use in human MBS procedures.

Esophageal magnetic compression anastomosis in dogs

BACKGROUND

Magnetic compression anastomosis (MCA) is a novel suture-free reconstruction of the digestive tract. It has been used in gastrointestinal anastomosis, jejunal anastomosis, cholangioenteric anastomosis and so on. The traditional operative outcomes of congenital esophageal atresia and benign esophageal stricture are poor, and there are too many complications postoperatively.

AIM

To test MCA technology to reconstruct the esophagus in dogs, prior to studying the feasibility and safety of MCA in humans.

METHODS

Thirty-six dogs were randomized into either the study or control group (n = 18 per group). The dogs in the study group were subjected to end-to-end esophageal anastomosis with the magnetic compression device, while those in the control group underwent hand-sewn anastomosis with 4-0 absorbable multifilament Vicryl. We used interrupted single-layer inverting sutures. The anastomosis time, gross appearance, weight and pathology of the anastomosis were evaluated at one month, three months and six months postoperatively.

RESULTS

The anastomosis time of the MCA group was shorter than that of the hand-sewn group (7.5 ± 1.0 min vs 12.5 ± 1.8 min, P < 0.01). In the MCA group, X-ray examination was performed every day to locate the magnetic device in the esophagus before the magnetic device fell off from the esophagus. In the hand-sewn group, dogs did not undergo X-ray examination. One month after the surgeries, the mean weight of the dogs in the hand-sewn group had decreased more than that of the dogs in the MCA group (11.63 ± 0.71 kg vs 12.73 ± 0.80 kg, P < 0.05). At 3 mo and 6 mo after the operation, the dogs' weights were similar between the two groups (13.75 ± 0.84 kg vs 14.03 ± 0.82 kg, 14.93 ± 0.80 kg vs 15.44 ± 0.47 kg). The number of inflammatory cells in MCA group was lower than that in hand-sewn group on 1 mo after operation.

CONCLUSION

MCA is an effective and safe method for esophageal reconstruction. The anastomosis time of the MCA group was less than that of the hand-sewn group. This study shows that MCA technology may be applied to human esophageal reconstruction, provided these favorable results are confirmed by more publications.

Establishment of Yan-Zhang's staging of digestive tract magnetic compression anastomosis in a rat model

Magnetic compression anastomosis, also known as magnamosis, is a safe and feasible method for digestive tract anastomosis. However, the pathological process involved in magnamosis of the digestive tract has not been investigated. This study aimed to establish the stages of digestive tract magnamosis in a rat model. Eighty-four Sprague–Dawley albino rats (200–250 g) were randomly divided into 14 groups (n = 6 per group). All rats underwent colonic magnamosis. Starting from postoperative day (POD) 1, one group of rats was sacrificed every other day to obtain the specimens. Burst pressure at the anastomotic site of each specimen was examined. Gross and histological examination of the anastomotic site was performed to establish the stages of the digestive tract magnamosis. Colonic magnamosis was successfully performed in all rats and the mean anastomosis time was 5.62 ± 0.91 min. The postoperative survival rate was 100%. The lowest anastomotic burst pressure was 78.33 ± 3.44 mmHg on POD3. The anastomotic burst pressure gradually increased and stabilized on POD21. Macroscopic and histological examination showed that the anastomotic mucosal and serosal layer did not heal on POD1. The serosal layer of the anastomosis healed by adhesion on POD3, and the mucosal layer began to heal on POD3-11 and was established by POD21. According to the anastomotic bursting pressure, digestive tract magnamosis can be staged into the magnetic maintenance, fragile, strengthening, and stable phases, which on histology correspond to the serosal adhesion formation, serosal healing, mucosal healing, and stereotyping, respectively.