Rapid Veno-venous bypass by magnetic anastomosis technique in ex situ liver resection animal model / 中华肝胆外科杂志

Objective To invent a set of novel veno-venous bypass (VVB) device based on magnetic anastomosis technique which can be used in ex situ liver resection, and verify its clinical value and performance in animal models.Methods Each VVB device was constructed using three magnetic rings and an inverted Y-shaped tube with magnetic rings on each end.The magnetic ring was made of NdFeB with electrode cutting, and the tube was made of polyvinyl chloride (PVC) and preconditioned with heparin coating on the surface of the lumen.Ten dogs underwent the ex situ liver resection, and VVB was established via magnetic anastomosis technique with the novel VVB device during the operation.The time for completing VVB was recorded, and the hemodynamic indexes including the venous flow velocity, carotid pressure, central venous pressure and portal pressure was detected.The changes of intestinal lumen and kidney were also observed.Results It only took 6 ～ 10 minutes to establish VVB by the novel VVB device in the operation,and the hemodynamics stability was maintained smoothly during the anheptic phase.The shunt index of inferior vena cava and portal vein was 76.2％ and 75.5％, respectively.The congestion of intestinal canal and kidney were also alleviated during the anheptic phase.Conclusions It could reduce the time to establish VVB with magnetic anastomosis technique in ex situ liver resection.This study showed that utilizing the novel VVB device for intraabdominal VVB during the anheptic phase could be helpful to maintain the hemodynamics stability.

Current status of veno-venous bypass in liver transplantation / 中华肝胆外科杂志

Since Shaw et al,first reported the first case successfully treated by veno-venous bypass (VVB),there has been great controversy on the routine application of VVB during conventional liver transplantation and piggyback liver transplantation in recent decades.With the improvements on the surgical skills,surgical techniques and anesthesiology,only a small portion of patients have the indications for VVB in liver transplantation routinely.This article reviews the current publications in this topic,which may provide new insight into the liver transplantation in clinical practice.

Discussion on the veno-venous bypass in autologous liver transplantation / 中华肝胆外科杂志

Liver transplantation is the main treatment for end-stage liver diseases and liver tumor.To solve the problem of the insufficient donor liver,autologous liver transplantation (ALT) is becoming widely acknowledged,which could serve as a complementary technique for treating unresectable liver space-occupying lesions in routine operation.However,compared with allogeneic liver transplantation,the long anhepatic phase during ALT may influence the outcome of such patients.Veno-venous bypass (VVB) as a technology which can maintain the stability of hemodynamics and internal environment in the anhepatic phase is routinely used in ALT.In this paper,the application of VVB in the ALT was mainly discussed.

Establishment and evaluation of models for small-for-size graft injury without veno-venous bypass in miniature pigs / 中华肝胆外科杂志

Objective To establish small-for-size (SFS) graft injury models in miniature pigs with high standardization, reproducibility and similarity to clinical situation. Methods Ba-Ma miniature pigs were introduced in this study and orthotopic liver transplantations (OLTs) were performed in 12 pigs with 30% liver volume allogeneil grafts (small portion of right paramedian lobe, right lateral lobe and caudate lobe) without veno-venous bypass. The profiles of intra-operational hemodynamics and metabolism were investigated. Animals were observed for 7 days with daily serum biochemistry and coagulation function exam. The survival rate related to operation itself and the SFS grafts were respectively calculated as well as the graft regenerative ratio at post-operational day (POD) 7. Results Graft weight as a percentage of the recipient's native liver weight (GW/RLW) and the total body weight (GW/BW) were (28. 63±4. 42)% and (0. 73±0.06)%. The mean operation time, anhepatic phase, and the time of blockage of infra-hepatic IVC were (191. 7±14. 2) min, (28. 3±3. 6) min, and (45. 0±5. 8) min. The survival rate related to the operation itself and the SFS graft were 83. 33% (10/12) and 40% (4/10), and the graft regenerative ratio at POD7 was (278. 06±42. 95) %. Contrast to the remarkable increase of heart rate and serum potassium during anhepatic phase, the mean arterial pressure, central venous pressure, rectal temperature, PH value and buffer excess had a significant decrease (P<0.01) with a gradual recovery after reperfusioa Serum ALT, AST, PT, Cr, and TB were significantly increased with a peak level at POD1 for the former 4 and POD2 for TB, and then began to decrease and favorably recovered at POD7, but TB, PT, and AST levels were still high when compared to those of prereperfusion (P<0. 05). Conclusion This model of OLT performed with 30% liver volume graft without veno-venous bypass was an ideal large animal model for series studies related to SFS graft injury.

Extracorporeal Venous Bypass in Porcine Orthotopic Liver Transplantation: A Comparative Study / 中国普外基础与临床杂志

Objective To explore the application of extracorporeal veno venous bypass in orthotopic liver transplantation in pigs and to compare hemodynamic changes during operation of two different bypass ways. Methods Twenty five porcine orthotopic liver transplantations were performed and extracorporeal veno venous bypass was established during anhepatic phase through a catheter in portal vein (group A, n =16) or in splenic vein (group B, n =9).Hemodynamic changes were monitored continuously.Results Fourteen recipients survived two days after operation (14/16) in group A while all survived in group B (9/9).Transient hemodynamic disturbance (MAP and CVP decreased,and HR increased) was monitored at both the beginning and the end of anhepatic stage in group A,while these parameters kept stable in group B ( P

Surgical Resection for HCC invading the Inferior Vena Cava: using veno-venous bypass and saphenous vein patch graft / 한국간담췌외과학회지

Technical advancement, accurate preoperative diagnosis, understanding of hepatic architecture and function, and enhanced anesthetic support have expanded the indications of hepatic resection while lowering perioperative morbidity and mortality. Especially in cases of infiltration of retrohepatic vena cava by tumor, aggressive hepatic resection involving the inferior vena cava( IVC ) has become safe and feasible using total vascular isolation(TVI) with veno-venous bypass and patch grafting. Authors reported a case of curative resection for hepatocellular carcinoma invading the inferior vena cava using TVI with veno-venous bypass and saphenous vein patch graft

Experience of an En Bloc Resection of Right Lobe of Liver, Adrenal, Kidney and Infrahepatic Vena Cava with the Aid of Veno-venous Bypass / 한국간담췌외과학회지

Resection of hepatic tumors located near the confluence of hepatic vein or invading retrohepatic vena cava has become technically feasible and relatively safe with the introduction of veno-venous bypass. Hepatic vascular exclusion(HVE) with the aid of veno-venous bypass using centrifugal pump enables safe resection and reconstruction of vena cava without hemodynamic instability, compared to conventional HVE. The authors report a case of a successful en bloc resection of right lobe and caudate process of liver, right adrenal, right kidney, and retrohepatic vena cava, in order to extirpate huge retroperitoneal tumor, with the aid of veno-venous bypass using centrifugal pump. Pathologic diagnosis revealed B cell type non Hodgkin's lymphoma arising from adrenal gland. After resection, caval defect was reconstructed with Dacron graft. Patency of reconstructed cava could be observed at five months postoperatively.

Acid-base and biochemical alterations and their analysis in clinical orthotopic liver transplantation with veno-venous bypass / 中华麻醉学杂志

Objective:To observe acid-base and biochemical changes in clinical orthotopic liver transplantation with veno-venous bypass.Method,Seven patients receiving orthotopic liver transplantation, veno-venous bypass was undergone in anheptic phase.The acid-base and biochemical parameters were monitored during operation. Result:Compared to preoperation,pH decreased a little in each phase,BE and SBC slightly decreased 60 min following bypass and during skin closure. Compared to before bypass,pH had no changes during bypass and new liver phases. The serum Ca~(2+) level decreased and serum glucose level elevated in each phase,The temperature gradually decreased during operation. The serum K~+ level was transiently elevated from 3.17mmol/L to 3.53 mmol/L early after the heptic revascularizaton. Conclusion:With the application of the veno-venous bypass technique,the hazard of acid-base and biochemical changes can be reduced during orthotopic heptic transplantation.

Anesthetic management for patients undergoing orthotopic liver transplantation / 中华麻醉学杂志

Objective To investigate the peri operative changes and anesthetic management during orthotopic liver transplantation (OLT) Methods General anesthesia or general anesthesia combined with epidural anesthesia was applied During the anhepatic phase, extracorporeal veno venous bypass (EVVB) was established Hemodynamics, respiratory function, blood gas, biochemistry, blood coagulation function, body temperature, blood glucose, urinary output and bleeding output were monitored According to the different characteristics of the pre anheptic phase, anheptic phase and neoheptic phase during OLT, the corresponding anesthetic management was supplied Results Applying EVVB during the anheptic phase could keep hemodynamics stable, but in 15 min of the primary anheptic and neoheptic stages a transient circulatory instablity occurred,and the rapid blood volume expansion was required Through comprehensive management, there was no obvious acid base disturbance during the phases The hypocalcemia, hypokalemia and hyperglycemia occurred and thebody temperature changed greatly,to require timly corrective measures Certain coagulative disturbances occurred, to require the supplement of coagulation factors, proper hemostatic drugs and protamine for neutralizing heparin Intraoperatively, anti rejection drugs were required Peri operatively, the blood glucose levels were higher than normal Conclusions Utilizing EVVB during the anheptic phase can be helpful to maintain hemodynamics stable, prevent obvious acidosis and hyperkalemia The anesthetic management during the neoheptic phase should be required to correcte hypothermia, hypocalcemia, hypokalemia, hyperglycemia and disturbence of coagulation

Changes of systemic and pulmonary hemodynamics during veno-venous bypass in liver transplantation / 中华麻醉学杂志

Objective To observe the changes of systemic and pulmonary hemodynamics during veno-venous bypass in liver transplantation Methods During the anhepatic phase, extracorporeal veno-venous bypass (EVVB) was utilized in 20 patients undergoing live transplantation Systemic and pulmonary hemodynamics were monitored through Swan-Ganz catheter during whole procedures Results As compared with the preoperative values , MAP remained unchanged in normal range during perioperative period;CO,CI,LVSW and RVSW decreased significantly during anhepatic phase and increased markedly 15 min after hepatic reperfusion (P

Influence of Changes in Mixed Venous Oxygen Tension(PvO2) by Extracorporeal Membrane Oxygenation(ECMO) on Hypoxic Pulmonary Vasoconstriction / 대한마취과학회지

Blood flow generally decreases to areas of the lung that become hypoxie, thereby reducing pulmonary shunt and preventing arterial hypoxemia. The mechanism of blood flow reduction in the hypoxic area is believed to be hypoxic pulmonary vasoconstriction(HPV). Over the years, serious attention has been given to the question of whether hypoxia of the airway(alveolar hypoxia) is the only way to elicit pulmonary vasoconstriction. the current consensus favors this traditional view. Even though the usual experiments have succeeded in proving that a large drop in alveolar PO2(PAO2) does elicit pulmonary vasoconstriction, they have not excluded the possibility that a sufficient drop in mixed venous PO(PvO2) may have the same eonsequenee. The purpose of this study is to test the hypothesis that a decrease in PvO2 may elicit hypoxic pulmonary vasoconstriction. For the selective change of PvOwe used venovenous extracorporeal circulation(VVECMO), a technique which had been tested for adequacy in hemodynamics and oxygenation in preliminary studies on 6 mongrel dogs. In eight pentobarbital-anesthetized, mechanically ventilated mongrel dogs, stepwise reductions in oxygen concentration(F1O2,) from 0.21 to 0.15 and 0.10 caused remarkable HPV. The mean pulmonary arterial pressure(MPAP) and the pulmonary vascular resistance(PVR) were increased from 17.3+/-3 mmHg and 185+/-64 dyne sec cm(-5) in normoxia(F1O2=0.21) to 30+/-6 mmHg and 401+/-257 dyne sec cm in severe hypoxia(F1O2=0.10, P(A)O2=30+/-9 mmHg), respectively ; while, in moderate hypoxia(F1OP2=0.15, P(A)O2=53+/-12 mmHg), only the MPAP increased and the increase was from 17.3+/-3 mmHg to 23+/-3 mmHg. The selective increase in PvO2without any change in P(A)O2 by extracorporeal veno-venous bypass from 37+/-6 mmHg and 22+/-4 mmHg to 54+/-8 mmHg and 45+/-5 mnHg in moderate and severe hypoxia, respectively, depressed HPV: decrease in MPAP in moderate hypoxia(MPAP=21+/-4 mmHg) and decrease in MPAP and PVR in severe hypoxia(MPAP=23+/-5 mmHg, PVR=319+/-228 dyne sec * cm(-5)). This study indicates that the mixed venous oxygen tension is an important determinant of the magnitude of hypoxic pulmonary vasoconstriction in diffuse alveolar hypoxia. Moreover, the method used in this study and the result might be useful other pulmonary pathophysiological studies and clinical situations with acute diffuse alveolar hypoxia, such as acute respiratory failure and chronic obstructive pulmonary diseases.

Orthotopic Liver Transplantation in Dogs by Veno - venous bypass using Centrifugal Pump / 대한마취과학회지

The Orthotopic liver transplantation for the terminal liver diseases has been performed frequently since the introduction of new immuno-suppressive agent (cyclosporin A), technical advances in surgical skill, uae of biopump during anhephatic stage, rapid infusion system for transfusion and thromboelastography for coagulopathies were used. In Korea, only one case of orthotopic liver transplantation succeeded in 1988, but the animal experiments have been going on for many years in many institutes. Orthotopic liver transplantation in dogs using centrifugal pump (Bio-pump) were experienced and the results were analysed; 1) There were no differences in hemodynamic parameters during anhepatic stage with assistance of Biopump compared with preanhephatic stage. 2) The mean flow rate of Biopump during anhepatic stage was 0.75+/-0.09L/min, and maximun and minimum flow rate were 1.5L/min. and 0.4L/min, respectively. 3) Mean artery pressure, cardiac output and systemic vascular resistance after reperfusion of transplanted liver were significantly reduced compared with the values of before reperfusion; meanwhile, mean pulmonary artery pressure, pulmonary capillary wedge pressure and pulmonary vascular resistance were not significantly different. 4) After reperfusion of transplanted liver serum potassium level was significantly increased to 6. 07+/-1.8 mEq/L and the amount of base was significantly decrease to-12.9+/-5.9 mEq/L. By using Bio-pump the degree of hemodynamic changes could be reduced during the clamping of inferior vena cava and hepatic vein.