Rat liver transplantation without preservation of “phrenic ring” using double cuff method

AIM: To develop a double cuff method for rat liver transplantationwithout preservation of “phrenic ring” to shorten the portalvein clamping time.METHODS: “Phrenic ring” was completely excluded fromthe donor liver,and end to end anastomosis of suprahepaticinferior vena cava was performed.RESULTS: The portal vein clumping time was shortened to10.6 min,the successful rate was 83.1%.CONCLUSION: This method can simplify the operation andshorten the portal vein clumping time.     

Chronological changes in the liver after temporary partial portal venous occlusion

AIM:To investigate time-dependent changes caused by temporal portal vein obstruction and subsequent reperfusion in the lobe with or without an occluded portal vein.METHODS:The portal vein(PV)of the anterior lobe of the liver of a male Wistar rat(8 wk-old)was obstructed(70%)for 12,24,36 and 48 h,respectively,and models were sacrificed at 48 h after reperfusion(each group:n=10).The histological changes and the status of liver regeneration were compared between a liver biopsy performed on each lobe after temporary obstruction of the portal vein in the same rat liver,and the liver extracted at the time of sacrifice(48 h after reperfusion).RESULTS:With regard to the obstructed lobe,the liver weight/body weight ratio significantly decreased according to obstruction time.On the other hand,in thenon-obstructed lobe,there were no significant differences within each group.The duration of PV occlusion did not seem to be strong enough to introduce liver weight increase.Stimulation of liver regeneration was brought about in the non-occluded lobe by 12-h occlusion,and was sustained even at 48 h after reperfusion.The obstructed lobe atrophied with the passage of time in the obstructed state.However,the proliferating-cell nuclear antigen labeling index also increased at 48 h after reperfusion,and a repair mechanism was observed.CONCLUSION:Temporary blood flow obstruction of the portal vein may become a significant trigger for liver regeneration,even with an obstruction of 12 h.     

Establishment of a new pig model for auxiliary partial orthotopic liver transplantation

AIM: To establish a new pig model for auxiliary partial orthotopic liver transplantation (APOLT). METHODS: The liver of the donor was removed from its body. The left lobe of the liver was resected in vivo and the right lobe was used as a graft. After the left lateral lobe of the recipient was resected, end-to-side anastomoses of suprahepatic inferior vena cava and portal vein were performed between the donor and recipient livers, respectively. End-to-end anastomoses were made between hepatic artery of graft and splenic artery of the host. Outside drainage was placed in donor common bile duct. RESULTS: Models of APOLT were established in 5 pigs with a success rate of 80%. Color ultrasound examination showed an increase of blood flow of graft on 5th d compared to the first day after operation. When animals were killed on the 5th d after operation, thrombosis of hepatic vein (HV) and portal vein (PV) were not found. Histopathological examination of liver samples revealed evidence of damage with mild steatosis and sporadic necrotic hepatocytes and focal hepatic lobules structure disorganized in graft. Infiltration of inflammatory cells was mild in portal or central vein area. Hematologic laboratory values and blood chemical findings revealed that compared with group A (before transplantation), mean arterial pressure (MAP), central venous pressure (CVP), buffer base (BB), standard bicarbonate (SB) and K+ in group B (after portal vein was clamped) decreased (P<0.01). After reperfusion of the graft, MAP, CVP and K+ restored gradually. CONCLUSION: Significant decrease of congestion in portal vein and shortened blocking time were obtained because of the application of in vitro veno-venous bypass during complete vascular clamping. This new procedure, with such advantages as simple vessel processing, quality anastomosis, less postoperative hemorrhage and higher success rate, effectively prevents ischemia reperfusion injury of the host liver and deserves to be spread.     

Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

AIM： To explore the influence of portal vein hemodynamic changes after portal venous arterialization （PVA） on peribiliary vascular plexus （PVP） morphological structure and hepatic pathology, and to establish a theoretical basis for the clinical application of PVA. METHODS： Sprague-Dawley rats were randomly divided into control and PVA groups. After PVA, hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound, liver function tests, ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization, and pathological examination was performed on tissue from the bile duct wall and the liver. RESULTS： After PVA, the cross-sectional area and blood flow of the portal vein were increased, and the increase became more significant over time, in a certain range. If the measure to limit the flow in PVA was not adopted, the high blood flow would lead to dilatation of intrahepatic portal vein and its branches, increase in collagen and fiber degeneration in tunica intima. Except glutamic pyruvic transaminase （GPT）, other liver function tests were normal. CONCLUSION： Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall. After PVA, It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux. A adequate measure to limit blood flow is necessary in PVA.     

Portal vein embolization induces compensatory hypertrophy of remnant liver

AIM:To evaluate the effectiveness and safety ofdifferent portal vein branch embolization agents ininducing compensatory hypertrophy of the remnantliver and to offer a theoretic basis for clinical portal veinbranch embolization.METHODS:Forty-one adult dogs were included in theexperiment and divided into four groups.Five dogsserved as a control group,12 as a gelfoam group,12as a coil-gelfoam group and 12 as an absolute ethanolgroup.Left portal vein embolization was performed ineach group.The results from the embolization in eachgroup using different embolic agents were compared.The safety of portal vein embolization(PVE)wasevaluated by liver function test,computed tomography(CT)and digital subtraction angiography(DSA)ofliver and portal veins.Statistical test of variance wasperformed to analyze the results.RESULTS:Gelfoam used for PVE was inefficient inrecanalization of portal vein branch 4 wk after theprocedure.The liver volume in groups of coil-gelfoamand absolute ethanol increased 25.1% and 33.18%,respectively.There was no evidence of recanalization ofembolized portal vein,hepatic dysfunction,and portalhypertension in coil-gelfoam group and absolute ethanolgroup.CONCOUSION:Portal vein branch embolization usingabsolute ethanol and coil-gelfoam could induce atrophyof the embolized lobes and compensatory hypertrophy ofthe remnant liver.Gelfoam is an inefficient agent.     

Portal hypertensive colopathy in patients with liver cirrhosis

AIM: In patients with liver cirrhosis and portal hypertension, portal hypertensive colopathy is thought to be an important cause of lower gastrointestinal hemorrhage. In this study, we evaluated the prevalence of colonic mucosal changes in patients with liver cirrhosis and its clinical significance. METHODS: We evaluated the colonoscopic findings and liver function of 47 patients with liver cirrhosis over a 6-year period. The main cause of liver cirrhosis was post-viral hepatitis (68%) related to hepatitis B (6%) or C (62%) infection. All patients underwent upper gastrointestinal endoscopy to examine the presence of esophageal varices, cardiac varices, and congestive gastropathy, as well as a full colonoscopy to observe changes in colonic mucosa. Portal hypertensive colopathy was defined endoscopically in patients with vascular ectasia, redness, and blue vein. Vascular ectasia was classified into two types: type 1, solitary vascular ectasia; and type 2, diffuse vascular ectasia. RESULTS: Overall portal hypertensive colopathy was present in 31 patients (66%), including solitary vascular ectasia in 17 patients (36%), diffuse vascular ectasia in 20 patients (42%), redness in 10 patients (21%) and blue vein in 6 patients (12%). As the Child-Pugh class increased in severity, the prevalence of portal hypertensive colopathy rose. Child-Pugh class B and C were significantly associated with portal hypertensive colopathy. Portal hypertensive gastropathy, esophageal varices, ascites and hepatocellular carcinoma were not related to occurrence of portal hypertensive colopathy. Platelet count was significantly associated with portal hypertensive colopathy, but prothrombin time, serum albumin level, total bilirubin level and serum ALT level were not related to occurrence of portal hypertensive colopathy. CONCLUSION: As the Child-Pugh class worsens and platelet count decreases, the prevalence of portal hypertensive colopathy increases in patients with liver cirrhosis. A colonoscopic examination in patients with liver cirrhosis is indicated, especially those with worsening Child-Pugh class and/or decreasing platelet count, to prevent complications such as lower gastrointestinal bleeding.     

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.METHODS:The new MCA device consists of a pair of titanium alloy and neodymium-ferrum-boron magnet(Ti-Nd Fe B)composite rings.The Nd Fe B magnetic ring as a core of the device was hermetically sealed inside the biomedical titanium alloy case.Twelve canines were divided into two groups:a MCA group in which the end-to-end anastomoses was made with a new device after resection in the portal vein and a traditional manual suture(TMS)group consisted of 6 canines.The anastomosis time,anastomotic patency and quality were investigated at week 24 postoperatively.RESULTS:The portal vein was reconstructed successfully in all of the animals and they all survived.The duration of portal vein anastomosis was significantly shorter in the MCA group than in the TMS group(8.16±1.25 vs 36.24±2.17 min,P0.05).Portography and ultrasound showed that the blood flow was normal without angiostenosis or thrombosis in all of the canines.Hematoxylin-eosin staining and electron microscope scanning showed in contrast to the TMS group,MCA anastomotic intimal was much smoother with more regularly arranged endothelial cells at week 24 postoperatively.     

Left-sided gallbladder： Its clinical significance and imaging presentations

AIM： To assess the importance of preoperative diagnosis and presentation of left-sided gallbladder using ultrasound （US）, CT and angiography.
METHODS： Retrospective review of 1482 patients who underwent enhanced CT scanning was performed. Left-sided gallbladder was diagnosed if a right-sided ligamentum teres was present. The image presentations on US, CT and angiography were also reviewed.
RESULTS： Left-sided gallbladder was diagnosed in nine patients. The associated abnormalities on CT imaging included portal vein anomalies, absence of umbilical portion of the portal vein in the left lobe of the liver, club-shaped portal vein in the right lobe of the liver, and difficulty in identifying segment Ⅳ. Angiography in six of nine patients demonstrated abnormal portal venous system （trifurcation type in four of six patients）. The main hepatic arteries followed the portal veins in all six patients. The segment Ⅳ artery was identified in four of six patients using angiography, although segment Ⅳ was difficult to define on CT imaging. Hepatectomy was performed in three patients with concomitant liver tumor and the diagnosis of left-sided gallbladder was confirmed intraoperatively.
CONCLUSION： Left-sided gallbladder is an important clinical entity in hepatectomy due to its associated portal venous and biliary anomalies. It should be considered in US, CT and angiography images that demonstrate no definite segment Ⅳ ,absence of umbilical portion of the portal vein in the left lobe, and club-shaped right anterior portal vein.     

Massive hepatic necrosis with toxic liver syndrome following portal vein ligation

Right portal vein ligation (PVL) is a safe and widespread procedure to induce controlateral liver hypertrophy for the treatment of bilobar colorectal liver metastases. We report a case of a 60-year-old man treated by both right PVL and ligation of the glissonian branches of segment 4 for colorectal liver metastases surrounding the right and median hepatic veins. After surgery, the patient developed massive hepatic necrosis with secondary pulmonary and renal insufficiency requiring transfer to the intensive care unit. This so-called toxic liver syndrome finally regressed after hemofiltration and positive oxygen therapy. Diagnosis of acute congestion of the ligated lobe was suspected. The mechanism suspected was an increase in arterial inflow secondary to portal vein ligation concomitant with a decrease in venous outflow due to liver metastases encircling the right and median hepatic vein. This is the first documented case of toxic liver syndrome in a non-cirrhotic patient with favorable issue, and a rare complication of PVL.     

Liver metastases with massive portal venous tumor thrombi from colorectal cancer: can be treated by surgical resection?

BACKGROUND/AIMS: The surgical treatments for liver metastases from colorectal cancer with massive portal venous tumor thrombi were evaluated. METHODOLOGY: Five patients, among the 142 patients who underwent hepatic resection for liver metastases from colorectal cancer from 1989 to 1998, were included in this study. The tumor thrombi in the main portal vein were removed by the following procedures; (1) the circumferential incision of the first branch of the portal vein and removal of the exposed tumor thrombi with ring forceps and suction, (2) temporary clamping of the distal end, (3) dilatation of the round ligament and the venous cannula was inserted into the umbilical portion, (4) washing out of the residual tumor thrombi, (5) declamping of the distal end and closing suture of the cut end of the portal branch. RESULTS: All patients had metachronous metastases and underwent resections of the primary tumor within 2 years. The surgical procedures performed were as follows: two cases that underwent right hepatectomies with portal venous tumor thrombectomies, one right trisectionectomy with portal venous tumor thrombectomy, one right hepatectomy plus limited resection of the contralateral lobe, and one left lateral sectionectomy with limited resection of the right lobe. All patients had no major postoperative complications and returned to their social lives within 1 month after operation. The intra-arterial catheter devices were implanted in four patients in order to receive adjuvant chemotherapy. One patient survived the 36-month period after liver resection, although 4 patients died of liver recurrence within 12 months. The mean survival time was 14.4 months and the overall 1-year survival rate was 20.0 percent. CONCLUSIONS: Surgical resection for this disease may bring longer survival rates for some patients, but not be an effective therapeutic option in our series. We should create other adjuvant therapies to improve these survival rates.     

三维肝脏快速容积采集整合阵列空间敏感编码技术在肝脏动态增强扫描中的应用

目的 评价三维肝脏快速容积采集(3D-LAVA)整合阵列空间敏感编码技术(ASSET)在肝脏动态增强扫描中的应用价值. 方法 对147例患者行磁共振常规平扫,并对其中90例行3D-LAVA增强扫描(其中72例整合ASSET),57例行二维陕速扰相梯度回波(2D-FSPGR)增强扫描(其中20例行肝门静脉增强磁共振血管成像).比较3D-LAVA和2D-FSPGR对不同病灶的显示能力,以及3D-LAVA整合ASSET前后的采集时间.将60例3D-LAVA采集的原始图像进行最大密度投影处理后,与20例肝门静脉增强磁共振血管成像进行对比,分析其对肝门静脉血管解剖的显示.结果 3D-LAVA对转移性肝癌敏感性高于2D-FSPGR(P＜0.05).3D-LAVA整合ASSET后,34例实现动脉早期、动脉期采集,23例实现动脉早期、动脉期和动脉晚期采集.60例门静脉期原始图像经最大密度投影处理后,与增强磁共振血管成像对肝内门静脉分支显示基本一致(P＞0.05).结论 3DLAVA整合ASSET在肝脏动态扫描中,在较短时间内可获得高质量的多期增强图像并可同时提供血管解剖信息,具有很高应用价值.     

"Forward" and "backward" flow mechanisms of portal hypertension. Relative contributions in the rat model of portal vein stenosis

The contribution of "forward" and "backward" flow mechanisms to the increased portal pressure observed in the rat model of portal vein stenosis was evaluated using experimental and theoretical data. The experimental data indicate that portal venous inflow, portasystemic shunting, and portal venous pressure are increased after 10 days of portal vein stenosis when compared with sham-operated controls. Furthermore, portal vascular resistance was 40% higher in portal hypertensive animals than in control animals. The elevated portal vascular resistance in the rat with portal vein stenosis was attributed to the high resistance of the portal venous collaterals. Incorporation of the experimental data into a mathematical model that simulated the changes induced by chronic portal vein stenosis allowed for fractionation of the "forward" and "backward" flow components involved in the pathogenesis of portal hypertension. Model predictions indicate that the "forward" and "backward" flow mechanisms account for 40% and 60% of the increase in portal pressure, respectively.     

Partial portal arterialization in complete en bloc resection of the hepatoduodenal ligament and left lobe of the liver for hepatic hilar cancer

The complete resection of the hepatoduodenal ligament is associated with enormous surgical invasion, which frequently results in postoperative hepatic dysfunction secondary to interruption of the reconstructed artery. We administered partial portal arterialization by anastomosis of the gastroduodenal artery to the portal vein without reconstruction of the hepatic artery in the complete resection of the hepatoduodenal ligament with resection of the left lobe of the liver in a patient with hilar bile duct carcinoma. After division of the proper hepatic artery, the gastroduodenal artery was anastomosed in an end-to-side fashion to the trunk of the portal vein. After division of the portal vein, to prevent ischemia, a single catheter bypass was inserted into a branch of the mesenteric vein and the another side of the catheter was attached to the hepatic end, of the portal vein. The portal vein was reconstructed with the superficial femoral vein graft. The blood supply to the remaining liver was interrupted for only 15 min during which the proximal end of the superficial femoral graft was anastomosed to the hepatic end of the portal vein. Postoperative liver function has been stabilized and his postoperative course is uneventful without portal hypertension. One month postoperatively, angiography through the vessels nourishing the raised jejunum visualized intrahepatic arteries.     

The study of endotoxin levels in portal venous system in liver cirrhosis

In the patients with liver cirrhosis, endotoxin levels were measured in portal venous system by the toxicolor method and the mechanism of endotoxemia in the peripheral vein was studied. On endotoxin levels in portal venous system, the superior mesenteric vein had the highest level. Endotoxemia was observed most frequently in the superior mesenteric vein (78%), and 50% in the truncal portal vein and 55% in the peripheral vein. The hepatic "endotoxin extraction ratio" which is considered to reflect the Kupffer cell function of clearing endotoxin and the severity of cirrhosis were not related each other. On the other hand, in view of the extrahepatic portal shunt, systemic endotoxemia appeared more frequently in the patients with the other collaterals than the esophageal varices. Therefore, it was concluded that systemic endotoxemia in liver cirrhosis was related with the type of extrahepatic portal collaterals.     

Portal vein arterialization technique for liver transplantation patients

Liver transplantations were performed on two patients with hepatic failure caused by liver cirrhosis. Hard obsolete thrombi and portal venous sclerosis were observed in the major portal veins of both patients. The arteria colica media of one recipient and the portal vein of the donor were anastomosed end-to-end. The hepatic artery of the first donor was anastomosed end-to end with the gastroduodenal artery of the first recipient; meanwhile, the portal vein of the second donor was simultaneously anastomosed end- to-end with the common hepatic artery of the second recipient. The blood flow of the portal vein, the perfusion of the donor liver and liver function were satisfactory after surgery. Portal vein arterialization might be an effective treatment for patients whose portal vein reconstruction was difficult.     

模拟肝段与超声图像的比较及其在教学中的应用

目的:探讨模拟肝段与超声图像的比较及其在教学中的应用.方法:使用橡皮泥按肝段的解剖比例,按标准形态制作8个橡皮泥肝段,然后组合成完整的模拟肝脏模型.按照肋间扫查的角度切割模拟肝脏.标准体型的人仰卧位,按照肋间隙从右上往左下依次扫查(第6-8肋间隙)3个切面.然后与模拟解剖肝脏的3个切面进行比较并分析所显示的肝段结构.结果:模拟肝脏的肋间切面与超声肋间切面能很好的吻合:橡皮泥肝脏A切面与B切面从上往下依次显示SⅤ、SⅧ、SⅦ肝段,超声图像a与b切面显示肝门静脉及肝静脉,门静脉以上部分为SⅤ,门静脉与肝静脉之间部分为SⅧ,肝静脉以下部分为SⅦ;橡皮泥肝脏C切面从上往下依次显示SⅤ、SⅥ、SⅦ肝段,超声图像c切面显示肝静脉断面及肝门静脉断面,门静脉右干至肝静脉断面部分为SⅤ,肝静脉断面至门静脉断面部分为SⅥ,门静脉断面以下部分为SⅦ.结论:通过切割橡皮泥肝脏模型,使超声断面上的肝段一目了然,对于学习超声肋间切面是个很好的学习方法,值得在教学中展开研究并应用.     

肝硬化患者肝功能失代偿状况与门脉管径的关系

目的:探讨肝硬化患者肝功能失代偿状况、食管静脉曲张程度与门脉主干内径及脾静脉内径的关系。方法:对100例肝硬化失代偿期患者进行肝功能Child-pugh分级,内镜检查判断食管静脉曲张程度,彩色多谱勒B超检测门静脉主干内径及脾静脉内径。结果:肝功能分级越差,门静脉与脾静脉的内径越大(P<0.05),且随着门静脉及脾静脉内径增大,食管静脉曲张程度亦加重(P<0.05)。结论:门静脉及脾静脉内径能间接体现门静脉高压的程度,继而反映肝功能失代偿状况。     

Impact of hepatic clearance of endotoxin using endotoxin activity assay

Background

Endotoxin (Et) in the portal vein blood is processed by the hepatic reticuloendothelial system, and therefore, it is possible that the hepatic clearance of Et may become a biological index for liver function. In this study, Et levels of preoperative peripheral and portal vein blood at the time of liver transplantation (LT) were measured in order to study the meaning.

Methods

The study population comprised 19 patients in whom pediatric living donor LT was performed. In the preoperative peripheral and the portal vein blood at the time of LT, we measured Et activity (EA) by the Et activity assay (EAA) and the Limulus amebocyte lysate (LAL) method.

Results

The preoperative peripheral vein blood showed a low EA in all cases. In the EA of the peripheral and the portal vein blood, the latter showed a significantly high level (p?=?0.049). With the LAL method, 5.3% (2/38) of patients were positive for Et.

Conclusions

The EAA is considered to be superior to the LAL method for the detection of Et, even in low endotoxinemia, and is also capable of elucidating the Et kinetics by accurately reflecting hepatic clearance.