A novel magnetic compression technique for cystostomy in rabbits

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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.

Section: Discussionmentioning

confidence: 99%

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

Zhang,

Zhong,

et al. 2024

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“…Past researchers have found that magnamosis can be applied for any anastomosis involving a lumen in the digestive tract, including esophageal 11 , esophagogastric 12 , gastrojejunal 13 , 14 , small intestine 15 , colon 16 , and biliary-enteric anastomosis 17 . Magnamosis can be used for vascular anastomosis 18 , 19 as well as for creating therapeutic 20 and pathological 21 fistulas.…”

Section: Introductionmentioning

confidence: 99%

Application of Y–Z deformable magnetic ring for recanalization of transanal single-access rectal stricture

Zhang,

Zhuang,

Mao

et al. 2024

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Magnetic compression anastomosis has been reported to have remarkable clinical outcomes. Here, we tested the applicability of a Y–Z deformable magnetic ring (DMR) for non-surgical manipulation of rectal stenosis (RS) in a beagle dog model under a transanal single-access condition. RS was modeled in 8 beagle dogs using partial ligation with silk thread. Under X-ray guidance, the Y–Z DMR was positioned at the proximal and distal ends of the RS, and the magnetic ring was bent into an “O” shape, such that the two rings were magnetically attracted. Operation time, complications during or after operation, and discharge time of the magnetic rings were recorded. The anastomosis bursting pressure was measured two weeks after removing the rings, and its formation was assessed through gross and histological examination. Partial ligation with a silk thread successfully established the canine RS model. After Y–Z DMR installation, the magnetic ring was successfully reconfigured from an “S” to an “O” shape. Strong attraction existed between the rings. The operation time was 9–15 min (average: 11.75 ± 1.98 min). No rectal bleeding or perforation occurred during or after operation. The ring was naturally expelled 7–10 days after surgery. A pressure of > 300 mmHg was recorded at the point of anastomosis rupture. The rectal anastomosis appeared to have healed properly on the surface, which was confirmed histologically, signifying the success of this procedure. A Y–Z DMR facilitated the successful recanalization of transanal single-channel RS without needing surgery in an animal model.

“…MCA has been under development for over 40 years, and its research fields have expanded from the initial vascular anastomosis and gastrointestinal anastomosis to ureterovesical anastomosis 5 , biliary stricture after liver transplantation 6 , 7 , esophageal stricture 8 , colorectal stricture 9 , and rectovaginal fistula closure repair 10 . MCA can also be used for therapeutic purposes of vesicostomy 11 and established pathological fistula animal models 12 .…”

Section: Introductionmentioning

confidence: 99%

Effect of tissue tension on magnetic compression anastomosis of digestive tract

Zhang,

Ma,

Shi

et al. 2024

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With the increasing application of magnetic compression anastomosis (MCA) in gastrointestinal anastomosis, we identified an interesting phenomenon that an anastomosis is more prone to stenosis after endoscopic gastrointestinal MCA. We hypothesized that the increase in tissue tension during endoscopic procedures is the cause of anastomotic stenosis. In this study, we investigated the effect of tissue tension on gastroduodenal bypass MCA in Sprague–Dawley (SD) rats. Twenty SD rats were divided into the study group (high-tension group, n = 10) and control group (no tension group, n = 10), wherein the rats underwent complete gastroduodenal bypass magnetic anastomosis under high tension and no tension of the digestive tract, respectively. Anastomotic specimens were obtained 4 weeks after the operation, and anastomotic diameters of the two groups were observed and measured. The histological difference was observed by hematoxylin & eosin and Masson staining. The operation was successfully completed in all rats, and all survived until 4 weeks postoperatively. Anastomotic measurements revealed that the anastomosis diameter was significantly smaller in the study group than in the control group, and there were three cases of severe anastomotic stenosis. Histological observation showed that the amount of collagen fibers in the anastomosis was greater in the study group than in the control group. The results suggest that the high-tension state of the digestive tract is an important factor leading to anastomotic stenosis, and thus, we put forward the Yan-Zhang’s Tissue Tension Theory of MCA to explain this phenomenon.