High-voltage pulsed electric field(HV-PEF)ablation technology has demonstrated promising applications in the clinical treatment of chronic obstructive pulmonary disease(COPD).However,its use has been limited to exploratory applications in a small number of cases,and the underlying mechanisms remain largely undefined.To facilitate broader clinical implementation,comprehensive molecular mechanism studies via extensive animal experimentation are essential.Rats,due to their ease of modeling COPD and the availability of comprehensive molecular reagents,serve as an optimal model for such studies.Consequently,the development of electrodes specifically designed for HV-PEF respiratory ablation in SD rats is of significant importance.In this study,we meticulously examined the anatomical structure of rat airways and investigated various equipment parameters,including material composition,rigidity,diameter,electrode ring dimensions,spacing between positive and negative poles,insulation coating for the catheters,welding techniques between the guidewire and electrode ring,and the design of vent holes in the catheter.Based on these considerations,we fabricated PVC ablation electrode catheters with integrated ventilation functionality.Subsequently,we employed finite element simulation to estimate the field strengths that could be applied by these electrodes.The simulation results were then validated in normal rats to assess the electrical safety and efficacy of the electrodes.These findings laid the groundwork for further investigation into the mechanisms of HV-PEF treatment for COPD.

Irreversible electroporation (IRE) is an emerging tissue ablation technique. Compared with thermal ablation technique such as radiofrequency, IRE can achieve focal ablation in a shorter time without heat sink effect while sparing the tissue scaffold. IRE has been demonstrated to be a feasible therapeutic modality for the liver, pancreatic, and prostatic cancer. In recent years, several studies regarding of catheter-directed IRE for digestive tract, bronchus, urinary tract, and myocardium have been performed, which preliminarily demonstrated the safety and efficacy of IRE for tissue ablation under endoscopic or interventional technique. This study summarized the research progress of catheter-directed IRE for tissue ablation. The critical technique and future direction of catheter-based IRE are prosp.
Catheter Ablation ; Catheters ; Electroporation ; Endoscopy ; Humans

Objective To investigate the effects of high intensity electric field on cell growth,apoptosis and microstructure of human pancreatic cancer cell line PANC-1.Methods The PANC-1 cells in the logarithmic growth period were selected,and cells in the high voltage electrical treatment group were treated with high voltage electric field 250,500,750,1000 V/cm,respectively.The effects of different high voltage electric fields on cell growth and microstructure of PANC-1 cells were determined by cell viability,cell death staining,apoptosis detection,transmission electron microscopy and scanning electron microscopy.Results Compared with control group,the high voltage electric pulse significantly inhibited the growth of PANC-1 cells in the field dependent manner.Moreover,when the field was more than 500 V/cm,the cell viability was significantly decreased (P＜0.05).High voltage electric pulse could induce cell apoptosis.When the field was higher than 750 V/cm,serious necrosis was noticed.In the 1000 V/cm group,the integrity of cell membrane and the structure of organelles was seriously damaged.Conclusion High voltage electric pulse could significantly inhibit the growth of PANC-1 cells and would be a promising method in cancer treatment.

A biliary contrast agents pushing device, including a syringe pushing system and a remote controller is introduced. The syringe pushing system comprises an injector card slot, a support platform and an injection bolus fader. A 20 mL syringe can be fitted on the syringe pushing system and kept with the ground about 30 degree. This system can perform air bubble pumping back and contrast agents bolus injection as well as speed adjustment. Remote controller is an infrared remote control which can start and stop the syringe pushing system. With this device, the remote controlled cholangiography technology can be achieved, which can not only protect doctors from X-ray radiation but also improve the traditional T-tube cholangiography and the contrast effect, reduce postoperative complications in patients as well. The application of this device will improve the current diagnosis and treatment system, the device will benefit the majority of doctors and patients.
Contrast Media ; administration & dosage ; Humans ; Injections ; Postoperative Complications ; Syringes

A magnetic anchoring supermicroinvasive laparoscopic system, including in vitro magnetic navigation handle and in vivo magnetic anchor laparoscopy is introduced. The magnetic anchor laparoscopic comprises an outer cannula, two data lines, a camera, a high color temperature LED light and two inner magnets. It is tiny enough to enter the abdominal cavity through conventional laparoscopic trocar and achieve orientation, navigation as wel as adjustment thefi eld of view within the abdominal cavity by attracting with the in vitro magnetic handle, thus it does not take up space of the laparoscopic trocar in working state. The system which can not only apply in single-port laparoscopic surgery based on a single traditional laparoscopic trocar but also apply in traditional laparoscopic surgery with less trocar, wil enhance the extent of minimaly invasive surgery and reduce the operation diffi culty at the same time. The clinical application of the system wil optimize the minimaly invasive techniques and benefi t the patients.

In recent years, the emergence of single-port laparoscopic technology promoted the development of the technology of laparoscopy, but deficiencies like equipment conflict or lack of triangulation severely hampered the clinical application of this technology. The appearance of single-port laparoscopic flexible instruments makes up for those deficiencies to a great extent. The element is to add a wrist joint to the tip of the instrument to form triangulation and reduce equipment conflict. But this technique is still in an early stage of development. The purpose of this article is to summarize the characteristics and problems of existing flexible single-port laparoscopic instruments, and to provide information for the further improvement, finally the future development was expected.
Equipment Design ; Humans ; Laparoscopy ; instrumentation

Liver transplantation is the only way to treat end-stage liver disease. In order to overcome the shortage of donor, marginal donors have been used widely, which bring about a series of problems. Machine perfusion can stimulate the circulation in vivo and is beneficial for the protection of liver. It could also improve the graft function and reduce postoperative complications, which makes it a hot spot in recent years. The aim of this study is to summarize the current status and prospects of application of machine perfusion on clinical liver transplantation.
Humans ; Liver ; Liver Transplantation ; Perfusion ; instrumentation ; methods ; Tissue Donors

This study was to build a canine portal hypertension model by intra-portal administration of high polymer material polyurethane and organic solvent tetrahydrofuran mixed solutions in order to evaluate the effectiveness of the model. Twelve local crossbreed dogs were selected randomly, with intra-portal administration of 8% (weight/volume) polyurethane- tetrahydrofuran solutions through an incision in the upper abdomen to build the portal hypertension model. We measured the portal vein pressure before modeling, during modeling, and four-, eight-, and twelve- weeks after modeling, respectively. Then we evaluated the effectiveness of the model comparing values of data with those data obtained before modeling started, which were regarded as the normal values. The results showed that the portal vein pressure rose by 2. 5 times after the solution administrated instantly as much as that before modeling, and maintained at 1. 5 times after 4 weeks. This method presents an easy operation, low animal mortality and reliable model of portal hypertension. Its less abdominal adhesions and its ability in keeping normal anatomic structure specially make it suit for surgical research of portal hypertension.
Animals ; Disease Models, Animal ; Dogs ; Furans ; adverse effects ; Hypertension, Portal ; Polyurethanes ; adverse effects ; Portal Vein ; physiopathology

OBJECTIVETo evaluate the feasibility of endoscopic gastrostomy combined with magnetic compression techniques in dogs.

METHODSThe magnetic compression device consisted of a couple of cylindrical magnets with a hole in the center. A 14-French gastric tube was inserted through the hole and fixed on the parent magnets. Four male mongrel dogs were selected randomly for the operation. The daughter magnet was placed into the dog's gastric body by a Zebra Guidewire under endoscopy, then a skin incision was performed on the left upper abdomen, through which the subcutaneous tissues and muscle were isolated up to the peritoneum. The parent magnet was placed on the surface of the peritoneum, which attracted the daughter magnet inside the gastric cavity automatically to compress the gastric wall and peritoneum. A needle was inserted through the gastric tube and punctured the tissue in the hole of the magnets repeatedly to form a fistula. After removing the needle, the gastrostomy was complete. The fistula was observed and its specimen was taken two weeks later under laparotomy.

RESULTSAll the four operations were successfully performed, and the operation time was 11-15 minutes. The stoma was matured immediately, through which early enteral nutrition support was administered. The gastric wall and peritoneum were observed with well healing and no adhesion in the abdominal cavity under laparotomy two weeks after the operation.

CONCLUSIONThe gastrostomy performed by magnetic compression technique combined with endoscopy is convenient, minimally invasive and safe, which may be used in future clinical practice.

Abdomen ; Animals ; Catheterization ; Dogs ; Enteral Nutrition ; Gastroscopy ; Gastrostomy ; Laparotomy ; Magnetics ; Male ; Santonin ; analogs & derivatives ; Stomach ; Surgical Stomas ; Wound Healing

Objective To evaluate the feasibility of endoscopic gastrostomy combined with magnetic compression techniques in dogs. Methods The magnetic compression device consisted of a couple of cylindrical magnets with a hole in the center. A 14-French gastric tube was inserted through the hole and fixed on the parent magnets. Four male mongrel dogs were selected randomly for the operation. The daughter magnet was placed into the dog′s gastric body by a Zebra Guidewire under endoscopy, then a skin incision was performed on the left upper abdomen, through which the subcutaneous tissues and muscle were isolated up to the peritoneum. The parent magnet was placed on the surface of the peritoneum, which attracted the daughter magnet inside the gastric cavity automatically to compress the gastric wall and peritoneum. A needle was inserted through the gastric tube and punctured the tissue in the hole of the magnets repeatedly to form a fistula. After removing the needle, the gastrostomy was complete. The fistula was observed and its specimen was taken two weeks later under laparotomy. Results All the four operations were successfully performed, and the operation time was 11-15 minutes. The stoma was matured immediately, through which early enteral nutrition support was administered. The gastric wall and peritoneum were observed with well healing and no adhesion in the abdominal cavity under laparotomy two weeks after the operation. Conclusion The gastrostomy performed by magnetic compression technique combined with endoscopy is convenient , minimally invasive and safe, which may be used in future clinical practice.