A new veno-venous bypass type for ex-vivo liver resection in dogs

Ex-vivo liver resection is a procedure in which the liver is completely removed, perfused and after bench surgery, the liver is autotransplanted to the original site. Ex vivo liver resection is an important treatment for unresectable liver tumors. This surgical procedure requires long operation time, during which blood flow must be carefully maintained to avoid venous congestion. An effective veno-venous bypass (VVB) may meet this requirement. The present study was to test our new designed VVB device which comprised one heparinized polyvinylchloride tube and three magnetic rings The efficacy of this device was tested in five dogs. A VVB was established in 6-10 minutes. There was no leakage during the procedure. Hemodynamics was stable at anhepatic phase, which indicated that the bypass was successful. This newly-developed VVB device maintained circulation stability during ex-vivo liver resection in our dog model and thus, this VVB device significantly shortened the operation time.

Esophageal magnetic compression anastomosis in dogs

BACKGROUND Magnetic compression anastomosis(MCA)is a novel suture-free reconstruction of the digestive tract.It has been used in gastrointestinal anastomosis,jejunal anastomosis,cholangioenteric anastomosis and so on.The traditional operative outcomes of congenital esophageal atresia and benign esophageal stricture are poor,and there are too many complications postoperatively.AIM To test MCA technology to reconstruct the esophagus in dogs,prior to studying the feasibility and safety of MCA in humans.METHODS Thirty-six dogs were randomized into either the study or control group(n=18 per group).The dogs in the study group were subjected to end-to-end esophageal anastomosis with the magnetic compression device,while those in the control group underwent hand-sewn anastomosis with 4-0 absorbable multifilament Vicryl.We used interrupted single-layer inverting sutures.The anastomosis time,gross appearance,weight and pathology of the anastomosis were evaluated at one month,three months and six months postoperatively.RESULTS The anastomosis time of the MCA group was shorter than that of the hand-sewn group(7.5±1.0 min vs 12.5±1.8 min,P<0.01).In the MCA group,X-ray examination was performed every day to locate the magnetic device in the esophagus before the magnetic device fell off from the esophagus.In the hand-sewn group,dogs did not undergo X-ray examination.One month after the surgeries,the mean weight of the dogs in the hand-sewn group had decreased more than that of the dogs in the MCA group(11.63±0.71 kg vs 12.73±0.80 kg,P<0.05).At 3 mo and 6 mo after the operation,the dogs’weights were similar between the two groups(13.75±0.84 kg vs 14.03±0.82 kg,14.93±0.80 kg vs 15.44±0.47 kg).The number of inflammatory cells in MCA group was lower than that in hand-sewn group on 1 mo after operation.CONCLUSION MCA is an effective and safe method for esophageal reconstruction.The anastomosis time of the MCA group was less than that of the hand-sewn group.This study shows that MCA technology may be applied to human esophageal reconstruction,provided these favorable results are confirmed by more publications.