Magnetic Compression Technique Research Articles

Establishment of acquired tracheoesophageal fistula using a modified magnetic compression technique in rabbits and its postmodeling evaluation

BACKGROUND Previous studies have validated the efficacy of both magnetic compression and surgical techniques in creating rabbit tracheoesophageal fistula (TEF) models. Magnetic compression achieves a 100% success rate but requires more time, while surgery, though less frequently successful, offers rapid model establishment and technical maturity in larger animal models. AIM To determine the optimal approach for rabbit disease modeling and refine the process. METHODS TEF models were created in 12 rabbits using both the modified magnetic compression technique and surgery. Comparisons of the time to model establishment, success rate, food and water intake, weight changes, activity levels, bronchoscopy findings, white blood cell counts, and biopsies were performed. In response to the failures encountered during modified magnetic compression modeling, we increased the sample size to 15 rabbit models and assessed the repeatability and stability of the models, comparing them with the original magnetic compression technique. RESULTS The modified magnetic compression technique achieved a 66.7% success rate, whereas the success rate of the surgery technique was 33.3%. Surviving surgical rabbits might not meet subsequent experimental requirements due to TEF-related inflammation. In the modified magnetic compression group, one rabbit died, possibly due to magnet corrosion, and another died from tracheal magnet obstruction. Similar events occurred during the second round of modified magnetic compression modeling, with one rabbit possibly succumbing to aggravated lung infection. The operation time of the first round of modified magnetic compression was 3.2 ± 0.6 min, which was significantly reduced to 2.1 ± 0.4 min in the second round, compared to both the first round and that of the original technique. CONCLUSION The modified magnetic compression technique exhibits lower stress responses, a simple procedure, a high success rate, and lower modeling costs, making it a more appropriate choice for constructing TEF models in rabbits.

Treatment of anastomotic stricture after rectal cancer operation by magnetic compression technique: A case report

BACKGROUND The treatment of postoperative anastomotic stenosis (AS) after resection of colorectal cancer is challenging. Endoscopic balloon dilation is used to treat stenosis in such cases, but some patients do not show improvement even after multiple balloon dilations. Magnetic compression technique (MCT) has been used for gastrointestinal anastomosis, but its use for the treatment of postoperative AS after colorectal cancer surgery has rarely been reported. CASE SUMMARY We report a 72-year-old man who underwent radical resection of colorectal cancer and ileostomy one year ago. An ileostomy closure was prepared six months ago, but colonoscopy revealed a narrowing of the rectal anastomosis. Endoscopic balloon dilation was performed three times, but colonoscopy showed no significant improvement in stenosis. The AS was successfully treated using MCT. CONCLUSION MCT is a minimally invasive method that can be used for the treatment of postoperative AS after colorectal cancer surgery.

Optimization of tracheoesophageal fistula model established with T-shaped magnet system based on magnetic compression technique.

The magnetic compression technique has been used to establish an animal model of tracheoesophageal fistula (TEF), but the commonly shaped magnets present limitations of poor homogeneity of TEF and poor model control. We designed a T-shaped magnet system to overcome these problems and verified its effectiveness via animal experiments. To investigate the effectiveness of a T-shaped magnet system for establishing a TEF model in beagle dogs. Twelve beagles were randomly assigned to groups in which magnets of the T-shaped scheme (study group, n = 6) or normal magnets (control group, n = 6) were implanted into the trachea and esophagus separately under gastroscopy. Operation time, operation success rate, and accidental injury were recorded. After operation, the presence and timing of cough and the time of magnet shedding were observed. Dogs in the control group were euthanized after X-ray and gastroscopy to confirm establishment of TEFs after coughing, and gross specimens of TEFs were obtained. Dogs in the study group were euthanized after X-ray and gastroscopy 2 wk after surgery, and gross specimens were obtained. Fistula size was measured in all animals, and then harvested fistula specimens were examined by hematoxylin and eosin (HE) and Masson trichrome staining. The operation success rate was 100% for both groups. Operation time did not differ between the study group (5.25 min ± 1.29 min) and the control group (4.75 min ± 1.70 min; P = 0.331). No bleeding, perforation, or unplanned magnet attraction occurred in any animal during the operation. In the early postoperative period, all dogs ate freely and were generally in good condition. Dogs in the control group had severe cough after drinking water at 6-9 d after surgery. X-ray indicated that the magnets had entered the stomach, and gastroscopy showed TEF formation. Gross specimens of TEFs from the control group showed the formation of fistulas with a diameter of 4.94 mm ± 1.29 mm (range, 3.52-6.56 mm). HE and Masson trichrome staining showed scar tissue formation and hierarchical structural disorder at the fistulas. Dogs in the study group did not exhibit obvious coughing after surgery. X-ray examination 2 wk after surgery indicated fixed magnet positioning, and gastroscopy showed no change in magnet positioning. The magnets were removed using a snare under endoscopy, and TEF was observed. Gross specimens showed well-formed fistulas with a diameter of 6.11 mm ± 0.16 mm (range, 5.92-6.36 mm), which exceeded that in the control group (P < 0.001). Scar formation was observed on the internal surface of fistulas by HE and Masson trichrome staining, and the structure was more regular than that in the control group. Use of the modified T-shaped magnet scheme is safe and feasible for establishing TEF and can achieve a more stable and uniform fistula size compared with ordinary magnets. Most importantly, this model offers better controllability, which improves the flexibility of follow-up studies.

A novel magnetic compression technique for establishment of a vesicovaginal fistula model in Beagle dogs

Vesicovaginal fistula lacks a standard, established animal model, making surgical innovations for this condition challenging. Herein, we aimed to non-surgically establish vesicovaginal fistula using the magnetic compression technique, and the feasibility of this method was explored using eight female Beagle dogs as model animals. In these dogs, cylindrical daughter and parent magnets were implanted into the bladder and vagina, respectively, after anesthesia, and the positions of these magnets were adjusted under X-ray supervision to make them attract each other, thus forming the structure of daughter magnet-bladder wall-vaginal wall-parent magnet. Operation time and collateral damage were recorded. The experimental animals were euthanized 2 weeks postoperatively, and the vesicovaginal fistula gross specimens were obtained. The size of the fistula was measured. Vesicovaginal fistula was observed by naked eye and under a light microscope. Magnet placement was successful in all dogs, and remained in the established position for the reminder of the experiment. The average operation time was 14.38 min ± 1.66 min (range, 12–17 min). The dogs were generally in good condition postoperatively and were voiding normally, with no complications like bleeding and urine retention. The magnets were removed from the vagina after euthanasia. The vesicovaginal fistula was successfully established according to gross observation, and the fistula diameters were 4.50–6.24 mm. Histological observation revealed that the bladder mucosa and vaginal mucosa were in close contact on the internal surface of the fistula. Taken together, magnetic compression technique is a simple and feasible method to establish an animal model of vesicovaginal fistula using Beagle dogs. This model can help clinicians study new surgical techniques and practice innovative approaches for treating vesicovaginal fistula.

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

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

A Novel Magnetic Compression Technique for Cystostomy in Rabbits

Zhang, Miaomiao; Yan, Xiaopeng MD, PhD; Mao, Jianqi MD; Li, Yixing MD; Xu, Shuqin PhD; Gai, Jingci MD; Lan, Ting MD; Wang, Yirui MD; Ren, Yuxiang MD; Lyu, Yi MBBS, MS, FACS Author Information

Tracheoesophageal fistula treated with magnetic compression technique in canines

There are various surgical methods for tracheoesophageal fistula; however, there is presently no unified standard. Based on the magnetic compression technique, we designed a novel method for the treatment of tracheoesophageal fistula. The purpose of this study was to verify its feasibility in an animal experiment. Six beagle dogs underwent surgical repair after constructing a tracheoesophageal fistula model. After the tracheal and esophageal spaces were freed during the operation, two magnets were used to clamp the fistula. The operation time, intraoperative blood loss, postoperative complications, and wound healing were monitored. Samples were obtained 14 days after the operation, and fistula repair was observed. The tracheoesophageal fistula repair operation was successfully completed for all six beagles. The average operation time was 23.67 ± 4.50 min. The average intraoperative blood loss was less than 10 mL. One dog had a postoperative wound infection, and the rest had no postoperative complications. The wound healed well. In all dogs, after specimen collection, it was observed that the fistula was successfully closed and the mucosal layer was smooth and flat. Histological observation showed that the anastomosis was slightly inflamed, the mucosal layer and surrounding tissues were arranged neatly, and the structure was slightly disordered. Magnetic compression technique can be effectively used to repair tracheoesophageal fistula, shorten the operation time, and simplify the operation procedure, and thus, it has the potential for clinical application.

An experimental study of magnetic compression technique for ureterovesical anastomosis in rabbits

This study aimed to explore the feasibility of the magnetic compression technique (MCT) for ureterovesical anastomosis in a rabbit model with ureteral obstruction. The distal ureteral obstruction model using female New Zealand rabbits was induced by ligating the distal end of the right ureter with silk thread for four weeks. A pair of cylindrical NdFeB magnets (daughter magnet and parent magnet) with a hole in the center was used for the ureterovesical anastomosis. The daughter magnet and the parent magnet were respectively placed close to the obstruction site through the dilated proximal ureter and urethra, and then the daughter-parent magnets pair was attracted together automatically. Postoperative X-rays were taken to confirm the position of the magnets. The anastomotic stoma specimens were obtained two weeks postoperatively, and the anastomotic stoma formation was observed by the naked eye and histological staining. The operation time and the anastomotic burst pressure were measured. The ureter was significantly dilated in the fourth week after ligation, which satisfied the placement of the daughter magnet. The ureterovesical magnet placements were successfully performed in ten experimental rabbits, with an operation time of 36.5 ± 6.09 min. The parent and daughter magnets attracted each other well and were subsequently removed through the urethra two weeks postoperatively, resulting in the establishment of ureterovesical anastomosis. The anastomotic burst pressure was 147.5 ± 14.59 mmHg. Gross specimens and histological examination of the anastomotic stoma showed that the anastomotic stoma healed well. MCT is feasible and simple for ureterovesical anastomosis.

Development of Magnetic Anastomat for Laparoscopic Bilioenterostomy

This work introduces the design and operating procedure of a novel magnetic anastomat for laparoscopic bilioenterostomy. Three techniques (magnetic compression technique, mechanic control technique and purse string suture technique) are used to design this device. The anastomat is mainly composed of two parts, a magnetic head and a handle. The surgical procedure for laparoscopic bilioenterostomy with this novel anastomat is similar to performing an end-side enteroenterostomy with the circular stapler. After the anastomosis is achieved, the magnetic head is placed at the anastomoses to maintain the digestive tract continuity. The magnetic head would fall into the jejunal lumen when the anastomoses is formed. This surgical approach would bring an innovation to the laparoscopic bilioenterostomy. Performing laparoscopic bilioenterostomy with this magnetic anastomat is safe, reliable and feasible.

Magnetic Compression Technique for Esophageal Anastomosis in Rats

The magnetic compression technique (MCT) is used for the anastomosis of hollow organs by the means of suction between magnets. The MCT is useful for establishing digestive tract anastomoses in rats, for example, end-to-side small intestinal anastomosis and colonic anastomosis. We aim to determine the feasibility of MCT-based esophageal anastomosis in rats. Twenty-four Sprague-Dawley albino rats (230-250g) were randomly divided into an MCT group and a control group (hand-sewn esophageal anastomosis). The time required to construct the anastomosis, postoperative complications, and survival rate was compared between the two groups. At 2wk postoperatively, the animals were sacrificed to assess the burst pressure and histological features of the anastomoses. The mean anastomosis time was significantly lower for MCT (11.17±1.64min) than for the hand-sewn technique (27.42±2.23min; P<0.001). The survival rate was slightly higher in the MCT group (91.67%) than in the control group (66.67%, P=0.317). The magnets were discharged from the body after 8.33±0.89d (range, 7-10d). No anastomotic leakage or stenosis occurred in the MCT group. Three rats developed anastomotic stenosis and two rats developed anastomotic leakage in the control group. The burst pressures were similar in the two groups. An histological examination showed that compared with the control group, the MCT group had better alignment of the tissue layers and less inflammation. The MCT is a simple and feasible technique for esophageal anastomosis in rats and has the potential for clinical application.

A novel magnetic compression technique for cystostomy in rabbits

Magnetic compression technique (MCT) is a popular new anastomosis method. In this paper, we aimed to explore the feasibility of use of MCT for performing cystotomy in rabbits. The parent magnets and daughter magnets for rabbit cystostomy were designed and manufactured according to the anatomical characteristics of rabbit lower urinary tract. Twelve female New Zealand rabbits were used as animal models. After anesthesia, a daughter magnet was inserted into the bladder through the urethra, and the parent magnet was placed on the body surface projection of the bladder over the abdominal wall. The two magnets automatically attract each other. Postoperatively, the state of magnets was monitored daily, and the time when the magnets fell off was recorded. Cystostomy with MCT was successfully performed in all twelve rabbits. The mean operation time was 4.46 ± 0.75 min. The magnets fell off from the abdominal wall after a mean duration of 10.08 ± 1.62 days, resulting in the formation of bladder fistula. Macroscopic and microscopic examination showed that the fistula was well formed and unobstructed. The junction between bladder and abdominal wall was tight and smooth. We provide preliminary experimental evidence of the safety and feasibility of cystostomy based on MCT.

Creation of gastroenteric anastomosis through natural orifice in rats by magnetic compression technique.

Being one of the core techniques of magnetic surgery, magnetic compression technique (MCT) has been used for digestive tract anastomosis reconstruction in experimental studies. This study verified the feasibility of gastroenteric anastomosis through natural orifice using MCT in rats. The parent and daughter magnets were designed and manufactured for oral and anal insertion in 20 Sprague-Dawley rats. After anesthesia, the parent magnet was inserted into the colon spleen area through the anus, and the daughter magnet was inserted into the stomach through the mouth. Then the two magnets were positioned to attract each other and bind together. The position of the two magnets was monitored using X-ray. The time required for the formation of the anastomosis and expulsion of the magnets were recorded. 2weeks later, the animal was sacrificed and the anastomotic specimen was obtained which was observed under naked eye and microscope. The gastroenteric anastomosis was successfully performed via natural orifices in 18 out of 20 rats. The mean time to construct the anastomosis was 3.78 ± 0.88min. X-ray examination showed that the magnets were in the appropriate position in 17 rats. The magnets were excreted in 9.47 ± 1.62days after surgery. The gross and microscopic examination of the specimen showed that the anastomoses were patent and the mucosa at the anastomotic was smooth. The mean bursting pressure of the anastomosis was 136.94 ± 6.79mmHg. It is feasible to perform gastroenteric anastomosis through natural orifices by MCT.

Experimental Study on the Establishment of Rat Model of Gastric Flstula by Magnetic Compression Technique

Experimental Study on the Establishment of Rat Model of Gastric Flstula by Magnetic Compression Technique

Feasibility Study of Magnetic Compression Technique for Colostomy in Rats

Feasibility Study of Magnetic Compression Technique for Colostomy in Rats

Construction of Esophagogastric Anastomosis in Rabbits with Magnetic Compression Technique

PurposeThe magnetic compression technique (MCT) is a new surgical method that has been used for gastrointestinal anastomosis, choledochojejunostomy, and intestinal anastomosis, but there are no reports on its use for esophagogastric anastomosis. This study aimed to investigate the feasibility of using MCT to fashion esophagogastric anastomoses in rabbits. MethodsTwenty rabbits were randomized into an MCT group (study group, n = 10) and a hand-sewn group (control group, n = 10). The magnetic compression anastomosis device used in this study was made of neodymium iron boron (NdFeB) and possessed parent (PMR) and daughter (DMR) magnetic rings. To fashion the anastomosis, the PMR and DMR were inserted into the lower esophagus and gastric fundus, respectively. The coupled magnets automatically compressed the sandwiched tissues and were expelled once the anastomosis was installed. The two groups were further compared in terms of the anastomosis construction time, survival rate, and postoperative complications. One month after the anastomosis was installed, the burst pressure and gross appearance of the anastomoses were evaluated. ResultsThe anastomosis construction time in the study group was significantly shorter than that in the control group (10.50±1.58 min vs. 18.60±2.22 min; P < 0.05), and the magnetic rings were defecated out in 10.70±3.49 days. The incidence of anastomotic blockage in both the study and control groups did not differ significantly (0%, 0/10 vs. 20%, 2/10; P > 0.05). Anastomotic leakage was not found in either of the groups, and the anastomoses burst pressures were similar in the two groups. However, the magnetically compressed anastomoses in the study group had a relatively smoother gross appearance than the hand-sewn anastomoses. ConclusionThe magnetic compression anastomosis device is a safe and feasible tool for fashioning esophagogastric anastomoses in this animal model.

Use of the magnetic compression technique in sleeve gastrectomy: a preliminary study.

Use of the magnetic compression technique in sleeve gastrectomy: a preliminary study.

Side to Side Intestinal Anastomosis Model in Rabbits Using Magnetic Compression Technique

Side to Side Intestinal Anastomosis Model in Rabbits Using Magnetic Compression Technique

An Exploratory Study of Bilioenteric Anastomosis by Magnetic Compression Technique in Rat Model

Ji, Lin MD; Kang, Shiran MD; Lyu, Yi FACS, MD, PhD; Yan, Xiaopeng MD, PhD Author Information

Use of the Magnetic Compression Technique in Sleeve Gastrectomy in a Rabbit Model

Journal of the American College of Surgeons 231(4):p e142, October 2020. | DOI: 10.1016/j.jamcollsurg.2020.08.374

Magnetic Compression Technique for Gastrointestinal Anastomosis in Rabbits

Magnetic Compression Technique for Gastrointestinal Anastomosis in Rabbits