Clinical feasibility of laparoscopic left lateral segment liver resection with magnetic anchor technique:The first clinical study from China

BACKGROUND Magnetic anchor technique(MAT)has been applied in laparoscopic cholecystectomy and laparoscopic appendectomy,but has not been reported in laparoscopic partial hepatectomy.AIM To evaluate the feasibility of the MAT in laparoscopic left lateral segment liver resection.METHODS Retrospective analysis was conducted on the clinical data of eight patients who underwent laparoscopic left lateral segment liver resection assisted by MAT in our department from July 2020 to November 2021.The Y-Z magnetic anchor devices(Y-Z MADs)was independently designed and developed by the author of this paper,which consists of the anchor magnet and magnetic grasping apparatus.Surgical time,intraoperative blood loss,intraoperative accidents,operator experience,postoperative incision pain score,postoperative complications,and other indicators were evaluated and analyzed.RESULTS All eight patients underwent a MAT-assisted laparoscopic left lateral segment liver resection,including three patients undertaking conventional 5-port and five patients having a transumbilical single-port operation.The mean operation time was 138±34.32 min(range 95-185 min)and the mean intraoperative blood loss was 123±88.60 mL(range 20-300 mL).No adverse events occurred during the operation.The Y-Z MADs showed good workability and maneuverability in both tissue and organ exposure.In particular,the operators did not experience either a“chopstick”or“sword-fight”effect in the single-port laparoscopic operation.CONCLUSION The results show that the MAT is safe and feasible for laparoscopic left lateral segment liver resection,especially,exhibits its unique abettance for transumbilical single-port laparoscopic left lateral segment liver resection.

Animal experimental study on magnetic anchor technique-assisted endoscopic submucosal dissection of early gastric cancer

BACKGROUND Gastric cancer(GC)has high morbidity and mortality.Moreover,because GC has no typical symptoms in the early stages,most cases are already in the advanced stages by the time the symptoms appear,thus resulting in poor prognosis and a low survival rate.Endoscopic submucosal dissection(ESD)can realize the early detection and diagnosis of GC and become the main surgical method for early GC.However,ESD has a steep learning curve and high technical skill requirements for endoscopists,which is not conducive to its widespread implementation and advancement.Therefore,a series of auxiliary techniques have been derived.AIM To evaluate the safety and efficacy of magnetic anchor technique(MAT)-assisted ESD in early GC.METHODS This was an ex vivo animal experiment.The experimental models were the isolated stomachs of pigs,which were divided into two groups,namely the study group(n=6)with MAT-assisted ESD and the control group(n=6)with traditional ESD.Comparing the total surgical time,incidence of surgical complications,complete mucosal resection rate,specimen size,and the scores of endoscopist’s satisfaction with the procedure reflected their feelings about convenience during the surgical procedure between the two groups.The magnetic anchor device for auxiliary ESD in the study group comprised three parts,an anchor magnet(AM),a target magnet(TM),and a soft tissue clip.Under gastroscopic guidance,the soft tissue clip and the TM were delivered to the pre-marked mucosal lesion through the gastroscopic operating hole.The soft tissue clip and the TM were connected by a thin wire through the TM tail structure.The soft tissue clip was released by manipulating the operating handle of the soft tissue clip in a way that the soft tissue clip and the TM were fixed to the lesion mucosa.In vitro,ESD is aided by maneuvering the AM such that the mucosal dissection surface is exposed.RESULTS The total surgical time was shorter in the study group than in the control group(26.57±0.19 vs 29.97±0.28,P<0.001),and the scores of endoscopist’s satisfaction with the procedure were higher in the study group than in the control group(9.53±0.10 vs 8.00±0.22,P<0.001).During the operation in the study group,there was no detachment of the soft tissue clip and TM and no mucosal tearing.The magnetic force between the AM and TM provided good mucosal exposure and sufficient tissue tension for ESD.The mucosal lesion was completely peeled off,and the operation was successful.There were no significant differences in the incidence of surgical complications(100%vs 83.3%),complete mucosal resection rate(100%vs 66.7%,P=0.439),and specimen size(2.44±0.04 cm vs 2.49±0.02,P=0.328)between the two groups.CONCLUSION MAT-ESD is safe and effective for early GC.It provides a preliminary basis for subsequent internal animal experiments and clinical research.

Magnetic anchor technique assisted endoscopic submucosal dissection for early esophageal cancer

BACKGROUND Esophageal cancer has high incidence globally and is often diagnosed at an advanced stage.With the widespread application of endoscopic technologies,the need for early detection and diagnosis of esophageal cancer has gradually been realized.Endoscopic submucosal dissection(ESD)has become the standard of care for managing early tumors of the esophagus,stomach,and colon.However,due to the steep learning curve,difficult operation,and technically demanding nature of the procedure,ESD has currently been committed to the development of various assistive technologies.AIM To explore the feasibility and applicability of magnetic anchor technique(MAT)-assisted ESD for early esophageal cancer.METHODS Isolated pig esophagi were used as the experimental model,and the magnetic anchor device was designed by us.The esophagi used were divided into two groups,namely the operational and control groups,and 10 endoscopists completed the procedure.The two groups were evaluated for the following aspects:The total operative time,perforation rate,rate of whole mucosal resection,diameter of the peering mucosa,and scores of endoscopists’feelings with the procedure,including the convenience,mucosal surface exposure degree,and tissue tension.In addition,in the operational group,the soft tissue clip and the target magnet(TM)were connected by a thin wire through a small hole at the tail end of the TM.Under gastroscopic guidance,the soft tissue clip was clamped to the edge of the lesioned mucosa,which was marked in advance.By changing the position of the anchor magnet(AM)outside the esophagus,the pulling force and pulling direction of the TM could be changed,thus exposing the mucosal peeling surface and assisting the ESD.RESULTS Herein,each of the two groups comprised 10 isolated esophageal putative mucosal lesions.The diameter of the peering mucosa did not significantly differ between the two groups(2.13±0.06 vs 2.15±0.06,P=0.882).The total operative time was shorter in the operational group than in the control group(17.04±0.22 min vs 21.94±0.23 min,P<0.001).During the entire experiment,the TM remained firmly connected with the soft tissue clip and did not affect the opening,closing,and release of the soft tissue clip.The interaction between the TM and AM could provide sufficient tissue tension and completely expose the mucosa,which greatly assists the surgeon with the operation.There was no avulsion of the mucosa,and mucosal lesions were intact when peeled.Therefore,the scores of endoscopists’feelings were higher in the operational group than in the control group in terms of the convenience(9.22±0.19 vs 8.34±0.15,P=0.002),mucosal surface exposure degree(9.11±0.15 vs 8.25±0.12,P<0.001),and tissue tension(9.35±0.13 vs 8.02±0.17,P<0.001).The two groups did not significantly differ in the perforation rate and rate of whole mucosal resection.CONCLUSION We found MAT-assisted ESD safe and feasible for early esophageal cancer.It could greatly improve the endoscopic operation experience and showed good clinical application prospects.

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.

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.