Miniature magnetically anchored and controlled camera system for trocar-less laparoscopy

AIM To design a miniature magnetically anchored and controlled camera system to reduce the number of trocars which are required for laparoscopy.METHODS The system consists of a miniature magnetically anchored camera with a 30° downward angle, an external magnetically anchored unit, and a vision output device. The camera weighs 12 g, measures Φ10.5 mm × 55 mm and has two magnets, a vision model, a light source, and a metal hexagonal nut. To test the prototype, the camera was inserted through a 12-mm conventional trocar in an ex vivo real liver laparoscopic training system. A trocar-less laparoscopic cholecystectomy was performed 6 times using a 12-mm and a 5-mm conventional trocar. In addition, the same procedure was performed in four canine models.RESULTS Both procedures were successfully performed using only two conventional laparoscopic trocars. The cholecystectomy was completed without any major complication in 42 min(38-45 min) in vitro and in 50 min(45-53 min) using an animal model. This camera was anchored and controlled by an external unit magnetically anchored on the abdominal wall. The camera could generate excellent image. with no instrument collisions.CONCLUSION The camera system we designed provides excellent optics and can be easily maneuvered. The number of conventional trocars is reduced without adding technical difficulties.

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.

Fedora-type magnetic compression anastomosis device for intestinal anastomosis

BACKGROUND Although previous studies have confirmed the feasibility of magnetic compression anastomosis(MCA),there is still a risk of long-term anastomotic stenosis.For traditional MCA devices,a large device is associated with great pressure,and eventually increased leakage.AIM To develop a novel MCA device to simultaneously meet the requirements of pressure and size.METHODS Traditional nummular MCA devices of all possible sizes were used to conduct ileac anastomosis in rats.The mean(±SD)circumference of the ileum was 13.34±0.12 mm.Based on short-and long-term follow-up results,we determined the appropriate pressure range and minimum size.Thereafter,we introduced a novel“fedora-type”MCA device,which entailed the use of a nummular magnet with a larger sheet metal.RESULTS With traditional MCA devices,the anastomoses experienced stenosis and even closure during the long-term follow-up when the anastomat was smaller thanΦ5 mm.However,the risk of leakage increased when it was larger thanΦ4 mm.On comparison of the different designs,it was found that the“fedora-type”MCA device should be composed of aΦ4-mm nummular magnet with aΦ6-mm sheet metal.CONCLUSION The diameter of the MCA device should be greater than 120%of the enteric diameter.The novel“fedora-type”MCA device controls the pressure and optimizes the size.

Study of Individual Characteristic Abdominal Wall Thickness Based on Magnetic Anchored Surgical Instruments

Background：Magnetic anchored surgical instruments （MASI）,relying on magnetic force,can break through the limitations of the single port approach in dexterity.Individual characteristic abdominal wall thickness （ICAWT） deeply influences magnetic force that determines the safety of MASI.The purpose of this study was to research the abdominal wall characteristics in MASI applied environment to find ICAWT,and then construct an artful method to predict ICAWT,resulting in better safety and feasibility for MASI.Methods：For MASI,ICAWT is referred to the thickness of thickest point in the applied environment.We determined ICAWT through finding the thickest point in computed tomography scans.We also investigated the traits of abdominal wall thickness to discover the factor that can be used to predict ICAWT.Results：Abdominal wall at C point in the middle third lumbar vertebra plane （L3） is the thickest during chosen points.Fat layer thickness plays a more important role in abdominal wall thickness than muscle layer thickness.＂BMI-ICAWT＂ curve was obtained based on abdominal wall thickness of C point in L3 plane,and the expression was as follow：f（x） =P1 × x^2 ＋ P2 x x ＋ P3,where P1 =0.03916 （0.01776,0.06056）,P2 =1.098 （0.03197,2.164）,P3 =-18.52 （-31.64,-5.412）,R-square：0.99.Conclusions：Abdominal wall thickness of C point at L3 could be regarded as ICAWT.BMI could be a reliable predictor of ICAWT.In the light of ＂BMI-ICAWT＂ curve,we may conveniently predict ICAWT by BMI,resulting a better safety and feasibility for MASI.