Tolerance limit of rats to normothermic hepatic inflow occlusion under portal blood bypass

Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-lished by clamping temporarily the pedicles of all liverlobes while the caudal lobe was kept as a passage ofthe portal blood flow. After hepatic blood flow re-stored, the caudal lobe was cut off. On the 7th postop-erative day, survival rate, hepatic morphological changes,and the severity and reversibility of the injured energymetabolism of the liver were investigated.Results: All rats that had been subjected to 30, 60 and90 minutes of hepatic inflow occlusion under portalblood bypass survived on the 7th postoperativeday. Ischemia-reperfusion injury of the liver was re-versible and compensatory in rats with hepatic inflowocclusion within 90minutes. However, the survivalrates of rats with 100, 110 and 120 minutes of hepaticinflow occlusion were 50%, 30% and 20% respective-ly. Liver injury of rats with 120 minutes of hepatic in-flow occlusion was severe and irreversible.Conclusions: The tolerance limit of rats to normother-mic hepatic inflow occlusion is enhanced significantlyunder portal blood bypass and the upper limit is 90minutes.

EXPERIMENTAL STUDY ON HEPATIC INFLOW OCCLUSION IN RABBITS

To evaluate the effect of hepatic inflow occlusion on the liver remnant, three methods of inflow occlusion of the right outside lobe of liver, which was finally resected, were performed in 30 rabbits. The mortality rate of 12 animals (6 in Group Ⅰ and 6 in Group Ⅱ) undergone 30 minutes of portal triad clamping (PTC) and selective hepatic artery reserving (SHAR) was both 66.7%. No death occurred in Group Ⅲ (PTC, n = 6) and Ⅳ (SHAR, n = 6) for 20 minutes of hepatic ischemia, but with an irreversible damage to the hepatocytes. The level of serum glutamic-yruvic transaminase (GPT) in Groups Ⅲ and Ⅳ animals rose to 282.17 U / L and 155.33 U / L on the first postoperative day and thereafter declining slowly to the preoperative level on the 5th and 3rd days, respectively. In Group V with selective hemihepatic vascular occlusion (SHHVO) serum GPT showed only temporary mild rise (112.83 U / L) on the first postoperative day and no hepatic pathologic change appeared. It is obvious that the function of the liver remnant can be best preserved during hepatic resection under SHHVO.

The effect of hepatic blood inflow occlusion on hepatic cancer treated with diode-laser thermocoagulation

Objective: To assess the effect of temporary occlusion of hepatic blood inflow on hepatic cancer treated with di- ode-laser induced thermocogation (LITT). Methods: The carcinoma Walker-256 was implanted in 40 SD rat livers. Twelve days later, the animals were randomly divided into 4 groups. Group A received LITT alone; group B received hepatic artery temporary occlusion during LITT; group C received portal vein temporary occlusion during LITT; group D received hepatic artery and portal vein temporary occlusion during LITT. Tumors were exposed to 810 nm diode-laser light at 0.95 watts for 10 min from a scanner tip applicator placed in the tumor. At the same time, the intrahepatic temperature distribution in rats with liver tumors was meas- ured per 2 min during thermocoagulation. Tumor control was examined immediately 7 and 14 d after thermocoagulation. Results: There was significant difference of intrahepatic temperature distribution in rats with liver tumors among the 4 groups (P<0.05) except when group C samples were compared with group D samples at each time point, and group B samples were compared with group C samples at 120 s (P>0.05). Light microscopic examination of the histologic section samples revealed three separate zones: regular hyperthermic coagulation necrosis zone, transition zone and reference zone. Compared with the samples in group A and group B, group C and group D samples had more clear margin among the three zones. Conclusion: The hepatic blood inflow occlusion, especially portal vein hepatic blood inflow occlusion, or all hepatic blood inflow occlusion considerably increased the efficacy of LITT in the treatment of liver cancer.

Hepatic blood inflow occlusion with/without hemihepatic artery control versus the Pringle maneuver in resection of hepatocellular carcinoma： a retrospective comparative analysis

Background The Pringle maneuver, which has been the standard for hepatic resection surgery for a long time, has the major flaw of ischemic damage in the liver. The aim of this research was to evaluate hepatic blood inflow occlusion with/without hemihepatic artery control vs. the Pringle maneuver in hepatocellular carcinoma （HCC） resection. Methods Two hundred and eighty-one cases of resection of HCC with hepatic blood inflow occlusion （with/without hemihepatic artery control） and the Pringle maneuver from January 2006 to December 2008 in our hospital were analyzed and compared retrospectively; among them 107 were in group I （Pringle maneuver）, 98 in group II （hepatic blood inflow occlusion）, and 76 in group III （hepatic blood inflow occlusion without hemihepatic artery control）. The operation time, intraoperative blood loss, postoperative liver function and complications were used as the endpoints for evaluation. Results The operative duration and intraoperative blood loss of three groups showed no significant difference; alanine aminotransferase, total bilirubin and incidence of postoperative complications were significantly lower in groups II and Ill postoperation than those in group I. Conclusion Hepatic blood inflow occlusion without hemihepatic artery control is safe, convenient and feasible for resection of HCC, especially for cases involving underlying diseases such as cirrhosis.

Approach to persistent ascites after liver transplantation

Persistent ascites(PA)after liver transplantation(LT),commonly defined as ascites lasting more than 4 wk after LT,can be expected in up to 7%of patients.Despite being relatively rare,it is associated with worse clinical outcomes,including higher 1-year mortality.The cause of PA can be divided into vascular,hepatic,or extrahepatic.Vascular causes of PA include hepatic outflow and inflow obstructions,which are usually successfully treated.Regarding modifiable hepatic causes,recurrent hepatitis C and acute cellular rejection are the leading ones.Considering predictors for PA,the presence of ascites,refractory ascites,hepatorenal syndrome type 1,spontaneous bacterial peritonitis,hepatic encephalopathy,and prolonged ischemic time significantly influence the development of PA after LT.The initial approach to patients with PA should be to diagnose the treatable cause of PA.The stepwise approach in evaluating PA includes diagnostic paracentesis,ultrasound with Doppler,and an echocardiogram when a cardiac cause is suspected.Finally,a percutaneous or transjugular liver biopsy should be performed in cases where the diagnosis is unclear.PA of unknown cause should be treated with diuretics and paracentesis,while transjugular intrahepatic portosystemic shunt and splenic artery embolization are treatment methods in patients with refractory ascites after LT.