Nonsuture anastomosis of arteries and veins using the magnetic pinned-ring device: a histologic and scanning electron microscopic study

The sealing effect of magnetic-sealing uterine manipulator in isolated uterus from patients with early-stage cervical cancer: a pre-clinical study

OBJECTIVE

Traditional uterine manipulator is considered as the main reason for short survival of patients with early-stage cervical cancer during minimally invasive surgery. This study aims to assess the sealing effect of magnetic-sealing uterine manipulators (MUMs) in isolated uteruses.

METHODS

The study was performed on isolated uterus from patients with early-stage cervical cancer who underwent open abdominal radical hysterectomy between November 2019 to April 2021. Right-angle forceps closure tests (groups 1 and 3) were defined as control tests. One experimental MUM closure test (group 2) and 2 control tests were respectively carried out in each of the isolated uterus. DNA ploidy analysis system was used to observe exfoliated cells. Statistical analysis was performed using Wilcoxon signed-rank test to assess the sealing effect of MUM.

RESULTS

We identified 36 patients. No regional node metastasis was discovered and only one tumor was larger than 4.0 cm in diameter. The mean of exfoliated tumor cells in groups 1, 2, and 3 were 1, 1, and 2, respectively. There was no significant difference in the quantity of exfoliated cells between groups 1 and 3 (p=0.476), so the results of the 2 groups were merged. Subsequently, a significant difference was observed between combined right-angle forceps closure tests and MUM closure tests (p=0.022).

CONCLUSION

The sealing effect of MUM was better than that of right-angle forceps. MUM can effectively seal cervical cancer cells in the cup cover, avoiding the dissemination of tumor cells.

TRIAL REGISTRATION

Chinese Clinical Trial Register Identifier: ChiCTR1900026012.

Magnetic-assisted laparoscopic liver transplantation in swine

BACKGROUND

Although laparoscopic technology has achieved rapid development in the surgical field, it has not been applied to liver transplantation, primarily because of difficulties associated with laparoscopic vascular anastomosis. In this study, we introduced a new magnetic-assisted vascular anastomosis technique and explored its application in laparoscopic liver transplantation in pigs.

METHODS

Two sets of magnetic vascular anastomosis rings (MVARs) with different diameters were developed. One set was used for anastomosis of the suprahepatic vena cava (SHVC) and the other set was used for anastomosis of the infrahepatic vena cava (IHVC) and portal vein (PV). Six laparoscopic orthotopic liver transplantations were performed in pigs. Donor liver was obtained via open surgery. Hepatectomy was performed in the recipients through laparoscopic surgery. Anastomosis of the SHVC was performed using hand-assisted magnetic anastomosis, and the anastomosis of the IHVC and PV was performed by magnetic anastomosis with or without hand assistance.

RESULTS

Liver transplants were successfully performed in five of the six cases. Postoperative ultrasonographic examination showed that the portal inflow was smooth. However, PV bending and blood flow obstruction occurred in one case because the MVARs were attached to each other. The durations of loading of MVAR in the laparoscope group and manual assistance group for IHVC and PV were 13 ± 5 vs. 5 ± 1 min (P < 0.01) and 10 ± 2 vs. 4 ± 1 min (P < 0.05), respectively. The durations of MVAR anastomosis in the laparoscope group and manual assistance group for IHVC and PV were 5 ± 1 vs. 1 ± 1 min (P < 0.01), and 5 ± 1 vs. 1 ± 1 min (P < 0.01), respectively. The anhepatic phase was 43 ± 4 min in the laparoscope group and 23 ± 2 min in the manual assistance group (P < 0.01).

CONCLUSIONS

Our study showed that magnetic-assisted laparoscopic liver transplantation can be successfully carried out in pigs.

Implementation of sodium alginate-Fe3O4 to localize undiagnosed small pulmonary nodules for surgical management in a preclinical rabbit model

Many methods are used to locate preoperative small pulmonary nodules. However, deficiencies of complications and success rates exist. We introduce a novel magnetic gel for small pulmonary nodules localization in rabbit model, and furtherly evaluate its safety and feasibility. Rabbits were used as the experimental objects. A magnetic gel was used as a tracer magnet, mixed as sodium alginate-Fe₃O₄ magnetic fluid and calcium gluconate solution. In short-term localization, a coaxial double-cavity puncture needle was applied to inject the gel into the lung after thoracotomy, and a pursuit magnet made of Nd-Fe-B permanent magnetic materials was used to attract the gel representing location of the nodule. In long-term localization, the gel was injected under X-ray guidance. Imaging changes to the lung were observed under X-ray daily. Thoracotomy was performed to excise tissue containing the gel, and hematoxylin-eosin staining was used to observe the tissue on postoperative days 1, 3, 5, and 7. Observe tissues morphology of heart, liver, spleen, and kidney in the same way. The gel was formed after injection and drew lung tissue to form a protrusion from the lung surface under the applied magnetic field. No complication was observed. The shape and position of the gel had not changed when viewed under X-ray. Pathological analysis showed the gel had a clear boundary without diffusion of magnetic fluid. All tissues retained good histologic morphology and no magnetic fluid was observed. Our study preliminarily suggested that the technique using sodium alginate-Fe₃O₄ magnetic gel to locate small pulmonary nodules with guidance of X-ray, and to search for them under an applied magnetic field during the operation is safe and feasible.

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.

Fast and Effective Nonsuture Anastomosis of Magnetic Artificial Blood Vessel Transplantation for Caval Reconstruction in Canines

BACKGROUND

The resection and reconstruction of the vena cava is frequently needed in tumor resection. The goal of this study was to evaluate the performance of the magnetic compression anastomosis (MCA) device for fast nonsuture anastomosis of caval reconstruction with artificial blood vessel transplantation after resection in canines.

METHODS

The MCA device consisted of paired neodymium-ferrum-boron (Nd-Fe-B) magnetic rings that were coated with titanium nitride and embedded in a polypropylene shell. Artificial blood vessel transplantation procedure was performed in sixteen canines and then they were divided into 2 groups: MCA group (n = 8), in which the novel magnetic pinned-ring device was used, and the traditional manual suture group (n = 8). In situ artificial blood vessel anastomoses were performed in the inferior vena cava (IVC). The anastomosis time and anastomotic patency and quality were investigated through ultrasonographic scans, angiographic, gross observation, histological staining, and scanning electron microscopy at 24 weeks postoperatively.

RESULTS

The IVC anastomoses were reconstructed successfully in all canines and all animals survived. In the MCA group, the operation time for IVC anastomosis with artificial blood vessel was significantly shorter than that in the tradition manual suture group (P < 0.05). Vena cava angiography and ultrasound showed good blood patency. The scanning electron microscope showed the re-endothelialization was smooth and endothelial cells were arranged regularly at the anastomotic site. Histological examination confirmed that the MCA group was associated with infiltration of inflammatory cells compared with the manual suture group.

CONCLUSIONS

The MCA device combined with artificial blood vessels is applicable in reconstruction of large vessels after resection. The magnetic pinned-ring device offers a simple, fast, reliable, and effective technique for nonsuture artificial blood vessel anastomosis of caval reconstruction in canines, and the anastomosis is functionally better than the traditional sutured anastomosis.

End-to-end vascular anastomosis using a novel magnetic compression device in rabbits: a preliminary study

Magnetic compression anastomosis (MCA) has been appreciated as an innovative alternative to manual suturing in vascular reconstruction. However, magnetic devices have limitations in their applications. The present study aimed to introduce a newly developed magnetic device for end-to-end vascular anastomosis. Twenty male New Zealand rabbits were randomly assigned to receive end-to-end postcaval vein anastomosis using either a newly designed MCA device (Group MCA) or continuous-interrupted suturing (Group CIS). The anastomotic patency was evaluated by Doppler or venography immediately, 1 week, and 12 weeks after surgery. Anastomotic quality was evaluated gross and microscopic histological study 12 weeks after surgery. The procedure was successfully performed and all animals survived until sacrifice. The duration of surgery and anastomosis time in Group MCA were significantly shorter compared to Group CIS (all p < 0.001), and the incidence of anastomotic patency and postoperative morbidity were comparable between the two groups (all p > 0.05). Hematoxylin-eosin staining showed that anastomotic intima from Group MCA was much smoother with more regularly arranged endothelial cells than from compared to the Group CIS. A novel MCA device was successfully applied in rabbit vascular anastomosis. We demonstrated the reliability and effectiveness of this newly developed MCA in this study.

Magnetic compression anastomosis for the treatment of benign biliary strictures: a clinical study from China

BACKGROUND

Magnetic compression anastomosis (MCA) is a revolutionary minimally invasive method to perform choledochocholedochostomy in patients with benign biliary stricture (BBS). We conducted MCA for the treatment of severe BBS that could not be treated by conventional methods.

PATIENTS AND METHODS

Patients with BBSs that could not be treated using conventional treatments were included. All patients underwent percutaneous transhepatic biliary drainage (PTBD) before MCA, and underwent cholangiography via simultaneous PTBD and endoscopic retrograde cholangiopancreatography (ERCP). The MCA device consisted of a parent and a daughter magnet. The daughter magnet was delivered via the PTBD route to the proximal end of the obstruction, and the parent magnet was delivered via ERCP to the distal end of the obstruction. After recanalization, the MCA device was removed, and biliary stenting (or PTBD) was performed for at least 6 months.

RESULTS

Of the 9 patients (age 49 ± 12.9 years), 6 had undergone orthotopic liver transplantation. MCA was successful in all 9 patients. The stricture length was 3 ± 1.7 mm, and recanalization occurred after 16.3 ± 13.2 days. Multiple plastic stents (4 patients), fully covered self-expandable metallic stents (4 patients), or PTBD (1 patient) was used after recanalization. Two mild adverse events occurred (cholangitis, 1 patient; biliary bleeding, 1 patient), but were resolved with conservative treatment. Stents were retrieved after > 6 months, and no stenosis occurred during 2-66 months of stent-free follow-up.

CONCLUSION

The MCA technique is a revolutionary method for choledochocholedochostomy in patients with severe BBS unresponsive to conventional procedures.

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.

Fast magnetic reconstruction of the portal vein with allogeneic blood vessels in canines

BACKGROUND

The resection and reconstruction of large vessels, including the portal vein, are frequently needed in tumor resection. Warm ischemia before reconstruction might have deleterious effects on the function of some vital organs and therefore, how to reconstruct the vessels quickly after resection is extremely important. The present study was to introduce a new type of magnetic compression anastomosis (MCA) device to establish a quick non-suture anastomosis of the portal vein after resection in canines.

METHODS

The new MCA device consists of a pair of titanium alloy and neodymium-ferrum-boron magnet (Ti-NdFeB) composite rings. The NdFeB magnetic ring as a core of the device was hermetically sealed inside the biomedical titanium alloy case. Twelve canines were divided into two groups: a MCA group in which the end-to-end anastomoses was made with a new device after resection in the portal vein and a traditional manual suture (TMS) group consisted of 6 canines. The anastomosis time, anastomotic patency and quality were investigated at week 24 postoperatively.

RESULTS

The portal vein was reconstructed successfully in all of the animals and they all survived. The duration of portal vein anastomosis was significantly shorter in the MCA group than in the TMS group (8.16+/-1.25 vs 36.24+/-2.17 min, P<0.05). Portography and ultrasound showed that the blood flow was normal without angiostenosis or thrombosis in all of the canines. Hematoxylin-eosin staining and electron microscope scanning showed in contrast to the TMS group, MCA anastomotic intimal was much smoother with more regularly arranged endothelial cells at week 24 postoperatively.

CONCLUSIONS

The Ti-NdFeB composite MCA device was applicable in reconstruction of large vessels after resection. This device was easy to use and the anastomosis was functionally better than the traditional sutured anastomosis.

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.