Roux-en-Y choledochojejunostomy using novel magnetic compressive anastomats in canine model of obstructive jaundice

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

BACKGROUND

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.

METHODS

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. 2 weeks later, the animal was sacrificed and the anastomotic specimen was obtained which was observed under naked eye and microscope.

RESULTS

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 ± 0.88 min. X-ray examination showed that the magnets were in the appropriate position in 17 rats. The magnets were excreted in 9.47 ± 1.62 days 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 ± 6.79 mmHg.

CONCLUSION

It is feasible to perform gastroenteric anastomosis through natural orifices by MCT.

A novel micromagnetic ring used for biliary-enteric anastomosis in rats

BACKGROUND

To explore the feasibility of micromagnetic ring in establishing biliary-enteric anastomosis in a rat model.

METHODS

A new micromagnetic ring suitable for rat biliary-enteric anastomosis model was designed and fabricated. The common bile ducts of 20 Sprague-Dawley albino rats were ligated and dilated after 2 weeks. Surgery for biliary-enteric anastomosis was completed by using micromagnetic ring. The anastomosis time, postoperative survival rate, liver function, liver histopathology, and complications were recorded. After 28 days, anastomotic specimens were obtained to observe healing with the naked eye and light microscopy.

RESULTS

Among the 20 Sprague-Dawley albino rats, one rat showed bile leakage and died one week after ligation of the common bile duct and another rat was removed from the experiment because there was no obvious dilatation of the common bile duct. The remaining 18 rats successfully underwent surgery for biliary-enteric anastomosis using micromagnetic ring, with an average anastomosis time of 7.10 ± 1.15 min (range, 5.17-9.50 min). The expulsion time of micromagnetic anastomosis rings was 11.94 ± 2.48 days (range, 8-17 days). The bilirubin level dropped to normal 1 week after surgery. Biliary-enteric anastomotic specimens were obtained 28 days after surgery, and microscopic observation showed that the mucosal layer of the anastomosis had good continuity and the anastomosis was smooth.

CONCLUSION

A micromagnetic ring can be used to construct a rat biliary-enteric anastomosis model, and it offers advantages, such as simple operation and reliable anastomosis effect.

Cholangiojejunostomy Using a Novel Magnamosis Device: Initial Clinical Results

BACKGROUND

Cholangiojejunostomy (CJ) is a popular operation; however, no specific anastomotic device is available. A novel magnamosis device for CJ was developed in 2017; here, we evaluated the feasibility and safety of the device.

METHODS

Between January 2017 and December 2019, 23 patients who underwent CJ using a novel magnamosis device were enrolled. For the CJ: the parent magnet was placed in the proximal duct, and the purse-string suture was tightened over the rod of the parent magnet. The magnamosis device was introduced into the jejunum, and the mandrel penetrated the jejunum at the anastomotic site, before insertion into the rod of the parent magnet. After rotating the knob, the distance between two magnets was shortened enough to achieve coupling.

RESULTS

Sixteen patients (69.6%) underwent open CJ, while 7 (30.4%) underwent laparoscopic CJ; 21 patients (91.3%) underwent choledochojejunostomy, and 2 (8.7%) underwent right or left hepatic duct jejunostomy. The mean time for completion of CJ was 9.2±2.5 min; it was significantly shorter for open CJ than for the laparoscopic way (8±1.2 min vs. 11.8±2.5 min, P<0.05). Only one patient (4.3%) suffered bile leakage after operation and was cured by conservative treatment. The magnets were discharged with a postoperative duration of 66.7±47.2 days, with a 100% expulsion rate. After a median follow-up of 15 months, only one patient (4.3%) developed inflammatory anastomotic stricture.

CONCLUSION

The novel magnamosis device is a simple, safe, and effective modality for CJ.

Magnetic Compression Anastomosis in Laparoscopic Pancreatoduodenectomy: A Preliminary Study

BACKGROUND

Laparoscopic pancreatoduodenectomy (LPD) is a minimally invasive technique widely developed in the last few decades. Although magnetic compression anastomosis (magnamosis) is used during cholangiojejunostomy, its applicability in LPD has not yet been reported. Herein, we evaluated the feasibility and effectiveness of magnamosis in LPD.

METHODS

Between January 2018 and December 2019, seven patients who underwent laparoscopic magnetic compression choledochojejunostomy (LMC-CJ) or laparoscopic magnetic compression pancreatojejunostomy (LMC-PJ) in LPD were enrolled. After LPD, a parent magnet with or without a drainage tube was placed in the proximal bile duct and pancreatic duct of each patient. Daughter magnets were introduced to couple with the parent magnets at the desired sites. A close postoperative surveillance of magnet movements was performed. Various relevant data were collected, and all patients were followed up until February 2020.

RESULTS

LPD was successfully completed in all seven patients, of which seven underwent LMC-CJ and two received LMC-PJ. The median time needed for completion of LMC-CJ was 11 min (range, 8-16). The cost time for the two cases of LMC-PJ was 12 and 15 min, respectively. After a median time of 50 d (range, 40-170) postoperation, all magnets were expelled. No leakages of LMC-CJ or LMC-PJ were observed after operation. After a median follow-up period of 11 mo (range, 4-18), there was no incidence of anastomotic stricture.

Combined endoscopy/laparoscopy/percutaneous transhepatic biliary drainage, hybrid techniques in gastrointestinal and biliary diseases

In recent years, a wide range of gastrointestinal endoscopy techniques have been developed, such as endoscopic submucosal dissection (ESD) and endoscopic retrograde cholangiopancreatography (ERCP). Although ESD and ERCP have an important role in gastrointestinal and biliary diseases, each technique has its limitations. Hybrid techniques that combine endoscopic and surgical procedures have emerged that have the advantages of different procedures and negate their limitations at the same time. Laparoscopic endoscopic cooperative surgery and modified laparoscopic endoscopic cooperative surgery combine ESD and laparoscopic techniques to resect submucosal tumors with minimum resection area. Air leak test by intraoperative endoscopy can effectively identify a mechanically insufficient anastomosis and decrease the complication rate. The rendezvous technique that combines percutaneous transhepatic biliary drainage and endoscopy can be performed as a rescue approach for the treatment of biliary obstruction, stenosis and bile duct injuries. For patients with simultaneous presence of stones in the gallbladder and the common bile duct, the laparo-endoscopic rendezvous technique can perform ERCP and laparoscopic cholecystectomy at the same time and reduces the risk of pancreatic injury caused by ERCP. Biliobiliary and bilioenteric anastomosis using magnetic compression anastomosis is another choice for biliary obstruction. The most common used approach to deliver the magnets is by percutaneous-peroral tract. Laparoscopic-assisted ERCP is a safe and highly effective therapy for patients who develop biliary diseases after Roux-en-Y gastric bypass surgery.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Optimized force range of magnetic compression anastomosis in dog intestinal tissue

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Biomechanical and Performance Evaluation of Magnetic Elliptical-Ring Compressive Anastomoses

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Magnetic compression anastomosis for biliojejunostomy and pancreaticojejunostomy in Whipple's procedure: An initial clinical study

BACKGROUND AND AIM

Magnetic anastomosis has been attempted in biliary and intestinal reconstruction. The objective of the current study was to introduce an initial clinical use of magnetic compression anastomosis for pancreaticojejunostomy and biliojejunostomy in Whipple's procedure.

METHODS

Patients with peri-ampullary carcinoma and dilated bile and pancreatic ducts were prospectively enrolled from 2016 to 2017. After pancreaticoduodenectomy, an appropriate mother magnet and drainage tube was placed in the proximal bile duct and pancreatic duct. The daughter magnets were introduced to mate with the mother magnets at the anastomotic sites. A close postoperative surveillance and routine cholangiopancreaticography via the drainage tube were performed.

RESULTS

One female and three male patients with a median age of 69 years (range, 57-77) were included. The diameter of the common bile ducts and pancreatic ducts ranged from 8 to 15 mm, and 7 to 10 mm, respectively. The median time duration for biliojejunostomy and pancreaticojejunostomy was 7 (range, 5-8 min) min and 9 (range, 8-10 min) min, respectively. The median time of biliojejunostomy and pancreaticojejunostomy formation was 17 (range, 15-21 days) days and 11 (range, 10-18 days), respectively. With a median follow up of 313 days, one patient developed biliary anastomotic stricture at 11 months after surgery, and underwent stent placement via percutaneous transhepatic drainage sinus, and recovered well.

CONCLUSIONS

Magnetic anastomosis is safe, effective, and simple for both biliojejunostomy and pancreaticojejunostomy in Whipple's procedure.

Magnetic Anastomosis for Biliojejunostomy: First Prospective Clinical Trial

BACKGROUND

Magnetic compression anastomosis (magnamosis, MCA) has been verified safe and effective by us and others in animal bilioenteric anastomosis (BEA). The objective of the present study was to introduce clinical application of magnetic compression bilioenteric anastomosis (MC-BEA) with a unique device in series of patients.

METHODS

Patients with obstructive jaundice with an indication of BEA were prospectively enrolled from 2012 to 2015. After dissection of bile ducts, the mother ring and drainage tube were placed in the proximal bile duct and the purse-string suture was tightened over the drainage tube. The drainage tube was introduced into the jejunal lumen at the anastomotic site and used to guide the daughter ring to assemble with the mother ring. All the patients were routinely followed up for magnets discharge or any complications associated.

RESULTS

Forty-one patients were included. Thirty-four (82.9%) patients had a malignant primary disease, while seven (17.1%) had benign disease. The median time for MC-BEA was 10.5 min (interquartile range [IQR] 8.3-13.0 min). No perioperative morbidity or mortality associated with MC-BEA was observed. The median time for a patent bilioenteric anastomosis formation was 19.0 days (IQR 14.5-23.0 days), and the magnets were discharged with a median postoperative duration of 35.0 days (IQR 28.0-43.0 days). With a median follow-up of 547.5 days (range 223-1042 days), no patients had biliary fistula, while two (4.9%) developed anastomotic stricture at 4 months and 14 months after surgery, and underwent reoperation for reconstruction of BEA.

CONCLUSIONS

MCA is a safe, effective, and time-saving modality for biliojejunostomy.

Laparoscopic Magnetic Compression Biliojejunostomy: A Preliminary Clinical Study

BACKGROUND

Magnetic compression anastomosis is a feasible and effective method for bilioenteric anastomosis (BEA) in animal model. The objective of the present study was to report our initial clinical experience in laparoscopically magnetic compression bilioenteric anastomosis (LMC-BEA).

METHODS

Patients with obstructive jaundice who were candidates for LMC-BEA were prospectively enrolled from 2013 to 2015. All the procedures were performed laparoscopically. A mother magnet and drainage tube were placed in the proximal bile duct and tightened by a purse suture after dissection of the common bile duct. The drainage tube was introduced into the jejunal lumen at the anastomotic site and guided a daughter magnet to approximate the mother magnet. The two magnets mated at the anastomotic site. All the patients were routinely followed up for magnets discharge till the end of the study.

RESULTS

In total, four patients with malignant obstructive jaundice and one patient with benign biliary stricture were included. The median age was 70 y (range, 49-74 y). The median time for LMC-BEA was 12 min (range, 8-15 min). A complete anastomosis was confirmed after a median time of 21 d (range, 5-25 d) postoperatively by cholangiography via drainage tube. The magnets were expulsed around 41 d after surgery (range, 12-47 d) postoperatively. With a median follow-up of 313 d (range, 223-1042 d), no complications associated with magnetic anastomosis was documented, such as bile leakage or anastomotic stricture.

CONCLUSIONS

Magnetic compression is a promising alternate method for laparoscopic BEA. Among the five patients undergoing LMC-BEA, no one developed anastomotic complications.

Gastrojejunal anastomosis in rats using the magnetic compression technique

Rats are suitable animal models in which to study the effects of gastric bypass surgery. However, construction of gastrojejunal anastomosis in the rat is technically demanding and is associated with high rate of postoperative complications. The aim of this study was to explore the feasibility and efficacy of the magnetic compression technique (MCT) in side-to-side gastrojejunal anastomosis in rats. Thirty male rats underwent gastrojejunal anastomosis using one of three techniques: hand-sewn, magnetic compression using cuboid magnets, and magnetic compression using magnetic rings. The mean anastomosis time using the magnetic compression technique was significantly less than that of the hand-sewn technique (3.6 ± 0.96 and 6.50 ± 1.58 vs. 14.40 ± 2.37 minutes,). The survival rate was highest in animals treated with magnetic compression using cuboid magnets (100%), followed by animals treated with magnetic compression using magnetic rings (90%) and then hand sewing (70%). The mean burst pressure did not differ significantly between the magnetic compression and hand-sewn anastomoses. Anastomoses constructed by magnetic compression were smoother and flatter than hand-sewn anastomoses. The results showed that MCT is a simple and feasible method for gastrojejunal anastomosis in the rat.

Magnetic compression technique for colonic anastomosis in rats

BACKGROUND

Magnetic compression technique (MCT) is useful for construction of digestive tract anastomoses in pigs and dogs. This study determined the efficacy of MCT for performing colonic anastomosis in rats.

METHODS

Twenty male Sprague-Dawley rats (230-280 g) were randomly apportioned to a study group that underwent colonic anastomosis with MCT or a control group subjected to hand-sewn colonic anastomosis. The groups were compared for time to construct the anastomosis, survival rate, and postoperative complications. Animals were euthanized at 1 mo postsurgery to study the burst pressure and histology of the anastomoses.

RESULTS

The study group required significantly less time to construct the anastomosis (6.50 ± 1.58 min) than did the control (15.6 ± 2.22 min). The survival rate of the study group (100%) was significantly higher than that of the control group (60%). In the control group, three rats developed anastomotic leakage and one rat developed anastomotic obstruction. No anastomotic leakage or obstruction was observed in the study group. The burst pressures of the two groups were similar. Histology showed that the study group had better alignment of the tissue layers and less inflammation compared with the control group.

CONCLUSIONS

MCT is a safe and feasible technique for colonic anastomosis in rats, with better postoperative outcomes compared with hand-sewn anastomosis.

Case-control study of the efficacy of retrogastric Roux-en-Y choledochojejunostomy

The traditional, retrocolic/antegastric Roux-en-Y choledochojejunostomy is technically complicated, and the incidence of postoperative complications remains high. Here we report the outcome of 59 consecutively treated patients (study group, SG) that underwent a new choledochojejunostomy method in which the jejunal loop is passed behind the antrum pyloricum (retrogastric route). A retrospective comparison was made between this group of patients and 187 patients (control group, CG) that underwent conventional Roux-en-Y choledochojejunostomy (antegastric route). Baseline clinicopathological characteristics were similar in both groups, except for the BMI, which was significantly higher in the SG. The time spent on constructing the anastomosis, as well as overall postoperative complications, did not differ between groups. Compared with the CG, the incidence of postoperative delayed gastric emptying was decreased in the SG, and the time elapsed before the patients' first postoperative liquid food consumption was shorter. We ascribe these beneficial effects to the superiority of the modified, retropyloric choledochojejunostomy approach, and propose that this surgical technique is particularly suitable for obese patients, especially those with a short ascending bowel loop.

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.

Portacaval shunt established in six dogs using magnetic compression technique

BACKGROUND AND AIMS

Installing the transjugular intrahepatic portosystemic shunt for portal hypertension is relatively safe, but complications are still high. To explore a new method of portacaval shunt, the magnetic compression technique was introduced into the shunting procedure.

METHODS

A portal-inferior vena cava shunt was performed on 6 male mongrel dogs by two hemocompatible Nd-Fe-B permanent magnets, parent and daughter. The parent magnet was applied to the inferior vena cava guided by a catheter through the femoral vein. The daughter magnet was moved to the anastomosis position on the portal vein with a balloon catheter through the splenic vein. After the daughter magnet reached the target position, the two magnets acted to compress the vessel wall and hold it in place. Five to 7 days later, under X-ray guidance, the magnets were detached from the vessel wall with a rosch-uchida transjugular liver access set. One month later, histological analysis and portal venography were performed.

RESULTS

5-7 days after the first surgery, a mild intimal hyperplasia in the portal vein and the inferior vena cava, and continuity of the vascular adventitia from the portal vein to the inferior vena cava as observed. During the second surgery, the contrast media could be observed flowing from the portal vein into the inferior vena cava. Portal venography revealed that the portosystemic shunt was still present one month after the second surgery.

CONCLUSIONS

Magnamosis via a device of novel design was successfully used to establish a portacaval shunt in dogs.

Portacaval shunt established in six dogs using magnetic compression technique

BACKGROUND AND AIMS

Installing the transjugular intrahepatic portosystemic shunt for portal hypertension is relatively safe, but complications are still high. To explore a new method of portacaval shunt, the magnetic compression technique was introduced into the shunting procedure.

METHODS

A portal-inferior vena cava shunt was performed on 6 male mongrel dogs by two hemocompatible Nd-Fe-B permanent magnets, parent and daughter. The parent magnet was applied to the inferior vena cava guided by a catheter through the femoral vein. The daughter magnet was moved to the anastomosis position on the portal vein with a balloon catheter through the splenic vein. After the daughter magnet reached the target position, the two magnets acted to compress the vessel wall and hold it in place. Five to 7 days later, under X-ray guidance, the magnets were detached from the vessel wall with a rosch-uchida transjugular liver access set. One month later, histological analysis and portal venography were performed.

RESULTS

5-7 days after the first surgery, a mild intimal hyperplasia in the portal vein and the inferior vena cava, and continuity of the vascular adventitia from the portal vein to the inferior vena cava as observed. During the second surgery, the contrast media could be observed flowing from the portal vein into the inferior vena cava. Portal venography revealed that the portosystemic shunt was still present one month after the second surgery.

CONCLUSIONS

Magnamosis via a device of novel design was successfully used to establish a portacaval shunt in dogs.