肝缺血再灌注后肝内血流动力学的变化

目的探讨肝脏缺血再灌注（I／R）后肝内分流（IHSF）和功能性肝血流（FHBF）的变化。方法健康雄性SD大鼠l2只，作右侧颈动脉、颈静脉插管；开腹后，经回结肠静脉作门静脉插管，分别用以输血、输液、给药、留样、检测等。大鼠经部分肝I／R制模后，随机分为2组（每组6只）：（1）正常对照组（对照组），术中只分离肝周围韧带，不作肝门阻断及再灌注。（2）缺血再灌注组（1／R组，实验组），进行45min的肝门阻断及60min的再灌注。然后两组均经门静脉输注D一山梨醇（10mmol／L，0．2mL／min），2min后同时取颈动脉、门静脉、肝静脉血各1mL。测定门静脉血流量（PVF）、肝动脉血流量（HAF）。计算肝脏山梨醇摄取率、FHBF和IHSF。结果两组PVF，HAF及总肝血流量（THBF）无明显统计学差异；与对照组比较，I／R组肝脏山梨醇摄取率和FHBF减少，IHSF增加（P〈0．01）。结论肝I／R后，肝内血流动力学变化表现为肝内门一体分流开放，功能性肝血流减少。     

Effect of dopamine infusion on hemodynamics after hepatic denervation

BACKGROUND:. The effects of dopamine (DA) on systemic hemodynamics are better understood than its effects on hepatic hemodynamics, especially after liver denervation occurring during liver transplantation. Therefore, a porcine model was used to study DA's effects on hemodynamics after hepatic denervation. MATERIALS AND METHODS: Fifteen pigs underwent laparotomy for catheter and flow probe placement. The experimental group (n = 7) also underwent hepatic denervation. After 1 week, all pigs underwent DA infusion at increasing doses (3-30 mcg/kg/min) while measuring hepatic parameters [portal vein flow (PVF), hepatic artery flow (HAF), total hepatic blood flow (THBF = HAF + PVF), portal and hepatic vein pressures] and systemic parameters [heart rate (HR), mean arterial pressure (MAP)]. RESULTS: There was a significant increase in HAF from baseline to the 30 mcg/kg/min DA infusion rate (within-subjects P < 0.01), but the differences between the two groups were not significant. PVF and THBF showed large effects (increases) with denervation, but the increase in flow with DA infusion was not present after denervation. Perihepatic pressures were unchanged by denervation or DA. Heart rate differed significantly between the control and denervated animals at baseline, 3, 6, 12 (all P < 0.05), and 30 mcg/kg/min DA (P = 0.10). Control vs denervation MAP at baseline was 100 +/- 4 vs 98 +/- 4 Torr and at 30 mcg/kg/min it was 110 +/- 3 vs 101 +/- 5 mm Hg. CONCLUSIONS: Hepatic flows tended to be higher after denervation. HAF showed similar increases with DA in both control and denervation groups. Increases in PVF and THBF with DA infusion were not present after denervation. HR was significantly decreased and MAP tended to be lower after denervation. The HR and MAP response to DA was similar in both groups. Therefore, both denervation and DA infusion have an effect on systemic and hepatic hemodynamics.     

The Relationship between Portal Venous and Hepatic Arterial Blood Flow. I. Experimental Liver Transplantation

The relationship between the changes in portal venous and hepatic arterial blood flows, in the liver is a much disputed question, it has tremendous significance in the practice of transplantation, and an explanation has been available since 1981, when Lautt published the so-caled “adenosine washout theory”. According to our earlier observations the decrease of portal pressure or flow consistently led to an increase in hepatic artery flow. At the same time changes in hepatic artery flow or pressure seemed to produce only inconsistent effects on the portal circulation. In the present experiments liver transplantation (OLTX) was carried out on mongrel dogs by Starzl''s method. Electromagnetic flow probes were placed on the hepatic artery and the portal vein before removal of recipient’s liver, and after completion of all vascular anastomoses to the newly inserted liver, during the recirculatory phase of OLTX. The flow probes were connected to a Hellige electromagnetic flowmeter, portal venous and systemic arterial pressures were also recorded.The control HAF was 241±23 ml/min, the average PVF was 517±47 ml/min before removal of the recipients''s liver. In the recirculatory phase the HAF increased, by 71±12% (p < 0.001). The PVF decreased in most animals after OLTX. The decrease was in average –40.2±3.5% (p < 0.001). The THBF calculated by adding the HAF and PVF showed a small, but not significant decrease during recirculation.The systemic arterial pressure decreased slightly and portal vein pressure rose in most animals after OLTX. There was a substantial increase in portal inflow resistance and prehepatic arteriolar resistance and a decrease in hepatic artery resistance. The decrease of PVF after OLTX can be explained by progressive fluid accumulation in the liver parenchyma and increased sinusoidal and portal inflow resistance. The prolonged and continuous increase in hepatic artery flow during the recirculatory phase of OLTX may be due to the decrease of portal flow. The exact mechanism, by which a change in portal flow leads to arteriolar dilatation, can be most probably explained by the “adenosine washout theory” of Lautt.     

Prospective Evaluation of Intraoperative Hemodynamics in Liver Transplantation with Whole,Partial and DCD Grafts

The interaction of systemic hemodynamics with hepatic flows at the time of liver transplantation (LT) has not been studied in a prospective uniform way for different types of grafts. We prospectively evaluated intraoperative hemodynamics of 103 whole and partial LT. Liver graft hemodynamics were measured using the ultrasound transit time method to obtain portal (PVF) and arterial (HAF) hepatic flow. Measurements were recorded on the native liver, the portocaval shunt, following reperfusion and after biliary anastomosis. After LT HAF and PVF do not immediately return to normal values. Increased PVF was observed after graft implantation. Living donor LT showed the highest compliance to portal hyperperfusion. The amount of liver perfusion seemed to be related to the quality of the graft. A positive correlation for HAF, PVF and total hepatic blood flow with cardiac output was found (p = 0.001). Portal hypertension, macrosteatosis >30%, warm ischemia time and cardiac output, independently influence the hepatic flows. These results highlight the role of systemic hemodynamic management in LT to optimize hepatic perfusion, particularly in LDLT and split LT, where the highest flows were registered.     

Effect of dopamine infusion (3-30 microg/kg/min) on hepatic hemodynamics

BACKGROUND: While dopamine produces well-characterized dose-dependent effects on systemic hemodynamics, there is a paucity of information regarding its effects on hepatic hemodynamics. Infusion rates above 10 microg/kg/min are reported to produce significant vasoconstriction and impair organ perfusion. Therefore, donors are sometimes considered unsuitable when higher doses of dopamine are in use. The aim of this study was to determine the effect of increasing doses of dopamine on hepatic hemodynamics in a nonanesthetized swine model. MATERIALS AND METHODS: Sixteen pigs were instrumented with indwelling catheters in a peripheral artery, peripheral vein, portal vein, and hepatic vein and flow probes around the portal vein and hepatic artery. After recovery, the following variables were measured 10 +/- 1 days postinstrumentation: hepatic arterial flow (HAF), portal venous flow (PVF), mean systemic arterial pressure (MAP), central venous pressure (CVP), portal venous pressure (PVP), hepatic venous pressure (HVP), heart rate (HR). Recordings were obtained at baseline and subsequently when dopamine was infused at rates of 3, 6, 12, 15, 21, and 30 microg/kg/min increasing at 1-h intervals. RESULTS: HAF and PVF increased linearly over the entire infusion range, to 69 and 13% over baseline, respectively (P < 0.001, P < 0.05). Total hepatic blood flow rose 23% over baseline at the 30 microg/kg/min dosage (P < 0.01). MAP increased linearly 13% over the range 12 to 30 microg/kg/min (P < 0.001). CVP, HVP, and PVP did not change significantly. HR decreased from 12 to 15 microg/kg/min (P < 0.01), then increased from 15 to 30 microg/kg/min (P < 0.05). CONCLUSION: These data show that dopamine infused at dosages of 3-30 microg/kg/min augments HAF, PVF, and THBF and that this effect is linear. These results suggest high-dose dopamine infusion does not disqualify a potential donor liver for transplantation.     

Intraoperative flow measurement of native liver and allograft during orthotopic liver transplantation in children

Hepatic hemodynamic changes during liver transplantation (OLT) in children have not yet been studied. We measured intraoperative portal vein flow (PVF) and hepatic arterial flow (HAF) (mL/min) in 53 children and 58 grafts during OLT. Flows were measured in the native organ and in the allograft. In the native liver, PVF and HAF are similar; after transplantation they return to the physiological situation. No flow differences were seen between whole and partial grafts. Among the 8 (14%) portal vein thromboses, PVF was lower in both the native liver and the graft than in the no thrombosis group (P < .05). PVF <5 mL/min/kg was a risk factor to develop PV thrombosis. No graft loss occurred in 3 cases without PVF at the time of OLTs despite the observation that repermeabilization was not possible. In 4 patients with PVF <5 mL/min/kg, after tying a spontaneous spleno-renal shunt (n = 3) or performing a porto-renal vein anastomosis (n = 1), PVF reached >20 mL/min/kg, avoiding thrombosis. In conclusion, PVF and HAF measurements during pediatric OLT may predict patients at high risk for development of PV thrombosis.     

Experimental evaluation of the effects of the intraportal administration of cyclic guanosine monophosphate on ischemia/reperfusion in the porcine liver

This study was done to examine the protective effects of cyclic guanosine monophosphate (cGMP), a second messenger of nitric oxide, for ischemia/reperfusion injury of the liver, since it is known to induce vasodilatation and to inhibit platelet aggregation. Using an experimental model of porcine liver ischemia, 8-bromoguanosine 3′,5′ monophosphate, a cGMP analog, was continuously administered into the portal vein before ischemia and after reperfusion 30 min for each in the cGMP group (n=6). Saline water was administered in the same way in the control group (n=6). The cardiac output (CO), mean arterial blood pressure (MAP), portal venous flow (PVF), hepatic arterial flow (HAF), hepatic tissue blood flow (HTBF), and hepatic tissue cGMP level were determined. Hepatic enzymes and the bile discharge were also assessed as indicators of hepatic function. The hepatic tissue cGMP level was significantly higher, and PVF, HTBF, and the bile discharge were significantly greater in the cGMP group, while there were no remarkable differences between the groups with CO, MAP, HAF, and hepatic enzymes. In conclusion, the continuous supplementation of cGMP into the portal vein was found to be beneficial for preserving both the hepatic circulation and, consequently, the hepatic function of after warm ischemia of porcine liver.     

Direct measurement of hepatic blood flow during living donor liver transplantation in children

Background

The changes in liver blood flow associated with living donor liver transplantation (LDLT) in children have not yet been studied. The aim of the present study was to investigate changes in hepatic hemodynamics before and after pediatric partial liver transplantation.

Methods

In 7 pediatric recipients with congenital cholestasis and native liver Child-Pugh classes B and C, portal vein flow (PVF) and hepatic arterial flow (HAF) were measured using an ultrasonic transit time flow meter before removal of the native liver and after transplantation and compared with donor left PVF and donor left HAF.

Results

The mean portal contribution to total hepatic blood flow was markedly decreased in the recipient native liver compared with that in the donor (69% ± 15% vs 32% ± 15%; P = .0003) and after reperfusion changed to almost the same ratio as that in the donor liver (73% ± 18%; P < .0001).

Conclusion

The extreme imbalance between PVF and HAF that is common in implanted partial liver in adult LDLT recipients was not observed in pediatric LDLT. After transplantation of an appropriately sized liver graft, the portal contribution to total liver blood flow normalized to the value for normal liver.     

Changes in hepatic hemodynamics and oxygen consumption after partial hepatic congestion in dogs.

The effects of 66% hepatic congestion (group 2, n = 6) on liver blood flow and hepatic oxygen metabolism were investigated in anesthetized dogs using an ultrasonic transit time flowmeter. The results were compared with those for control dogs (group 1, n = 6) and for 60% hepatectomized dogs (group 3, n = 6) wherein almost the same amount of hepatic parenchyma was removed as was congested in group 2. Portal blood flow (PVF) in group 2 and group 3 decreased similarly to 60 and 63% of the baseline values, respectively (p less than 0.05). Cardiac output (CO) in group 2 and group 3 also decreased significantly in proportion to the decrease in PVF. Among the dogs in group 2, hepatic arterial blood flow (HAF) was fairly well maintained at 86% of the baseline value, despite the decrease of cardiac output, whereas the HAF in group 3 decreased to 49% of the baseline value at 1 h after hepatectomy. The calculated hepatic arterial resistance (HAR) in group 3 increased significantly due to the 60% loss of the hepatic arterial vascular bed. The HAR in group 2, by contrast, became lower than that in group 1, suggesting a compensatory decrease of HAR for the obstructed portal flow to the congested area. These results were well consistent with our angiographic findings (n = 3) that the portal flow to the congested segments was completely obstructed and the congested segments received only an arterial blood supply. The centrilobular hepatocytes of the congested segments showed marked vacuolar degeneration and the total hepatic oxygen consumption in group 2 was reduced (p less than 0.05). However, the decrease in oxygen consumption in group 2 was not so severe as in group 3 (p less than 0.05). These data suggest that some parts of the preserved congested segments were still viable and had the capacity of aerobic metabolism even 4 h after the ligation of the drainage vein of those segments. In this study, the importance of the hepatic arterial flow to the congested segment has been demonstrated. When the congested hepatic segment is to be preserved intraoperatively, care must be taken to maintain the hepatic arterial blood flow during the perioperative period.     

Evaluation of 133Xe washout kinetics by controlled pig liver perfusion in vivo

The interpretation of multiexponential curves from hepatic tracer washout for estimation of hepatic blood flow (THBF) was investigated, using hepatic ¹³³Xe washout during controlled portal and arterial perfusion of liver in anesthetized pigs. Variations of (1) THBF from 25 to 210 ml/min × 100 g, (2) the proportion of portal to arterial flow, and (3) the site of tracer application were performed. After portal injection the tracer curves were in most cases multiexponential; their analysis revealed that calculation of THBF using k values based on the monocompartmental hypothesis always grossly overestimated total flow. Estimation of THBF by height/area ($\text{H}\text{A}$), however, reflected the total flow in all cases. Only when hypoventilation or elevation of hepatic venous pressure was performed, did calculation of THBF from k values and $\text{H}\text{A}$ values reveal similar results. THBF when estimated from $\text{H}\text{A}$ and from indocyanine green dye extraction gave identical results, both in the controlled perfused liver and in the intact animal. Washout curve analysis after arterial Xe application showed neither a correlation with the total nor with the arterial flow, indicating incomplete mixing of both blood flow components. It is concluded that liver perfusion is multicompartmental and blood flow through the portal and arterial vascular bed is incompletely mixed. Therefore, THBF can be calculated only after portal tracer injection and when the mean transit time concept is applied.     

Arterialization of the portal blood with a new model of flow diversion: an experimental study

Arterialization of the portal blood with double shunts, cavo-mesenteric venous and femoro-femoral arterio-venous, was attempted in dogs. The experimental model was studied in three groups. Group-I was concerned with the condition immediately after establishment of the model. Group-II-A was referred to the study on the established model with hepatic artery ligation for seven days. Group-II-B was evaluated under hepatic artery ligation and absent participation in arterialization and shunts. The ratio of portal venous flow (PVF) to cardiac output (CO) in group-I revealed significant increase from 23 +/- 6% to 56 +/- 9% (p less than 0.01). Portal venous PO2 (PVO2) also increased from 48 +/- 7 mmHg to 65 +/- 9 mmHg (p less than 0.01). Portal venous pressure, however, remained below 200 mmH2O. Persistent increase of CO (150% of the control) and PVF/CO were seen in observation of group-II-A. Histopathological appearance of the liver was normal in group-II-A. Group-II-B revealed a high mortality rate (8/9) with necrosis of the liver by seventh postoperative day. The experimental model provides the useful flow diversion with arterialized blood to the portal flow. The arterialization of the portal flow may play an important role in the recovery of the ischemic liver cell in the preservation of the liver graft and in hepatic regeneration after extended resection.     

Enhanced hepatic portal blood flow induced by prostaglandin E1 following liver transplantation in pigs

Portal venous blood flow (PVF), hepatic arterial blood flow (HAF), and systemic arterial pressure (SAP) were examined after prostaglandin E₁ (PGE₁) was injected into the vena cava superior (VCS) of liver-transplanted pigs. The injection of PGE₁ at 0.2 g/kg/min for 2 min on the day of transplantation and 3 days later produced an increase in PVF without causing any change in HAF or SAP, the response in PVF being dose-dependent. However, no reliable change in PVF, HAF, or SAP was seen when the same dose of PGE₁ was administered 7 days after transplantation. Furthermore, no significant difference was noted among the values for PVF and total hepatic blood flow (THF) during the experimented days, although the HAF value had increased markedly 3 days after transplantation. These findings suggest that PGE₁ is effective in increasing PVF in the liver transplanted condition; however, the hepatic circulatory improvement attributed to this agent would be limited to the first few days following transplantation.     

脾切除贲门周围血管离断术后肝脏血流动力学和储备功能的变化

目的 研究脾切除贲门周围血管离断术后肝脏血流动力学及肝功能储备的变化.方法 对2006年6月至2007年8月在四川大学华西医院行脾切除贲门周围血管离断术的连续30例乙肝后肝硬化患者通过感应器连续测定手术中的门静脉压力梯度;运用彩色多普勒分别测最术前和术后肝动脉血流量、门静脉血流量、肝动脉阻力指数,通过术前和术后吲哚青绿试验分别测得有效肝血流量及ICGR15.结果 本组30例患者的门静脉压力梯度在开腹后为(19±4)mm Hg,结扎脾动脉后为(14±4)mm Hg,脾切除后为(14±3)mm Hg,贲门周围血管离断术后为(12±4)mm Hg,有逐渐下降的趋势.术后门静脉血流餐由(42±14)ml/s降至(16±8)ml/s,而肝动脉血流量代偿性增加.术后有效肝血流量由(0.48±0.10)L/min增至(0.56±0.10)L/min,而ICGR15由22%±8%减至18%±4%.结论 脾切除贲门周围血管离断术后,尽管门静脉压力梯度及门静脉血流量减少,但肝功能储备至少在术后短期内是得到了改善的.     

The effects of intravenously infused catecholamines on hepatic blood flow in conscious dogs with experimental obstructive jaundice

This study was conducted to examine how the effects of dopamine and dobutamine on hepatic blood flow were influenced by obstructive jaundice in a conscious canine model. Prior to biliary obstruction, portal venous blood flow (PVF) increased in response to the infusion of either dopamine or dobutamine: dopamine infused at 8 g/kg per min produced an increase of 19±0% in PVF, while dobutamine infused at 16 g/kg per min produced an increase of 30±2%. Although hepatic arterial blood flow (HAF) decreased dose-dependently in response to the infusion of dopamine, no significant change was observed in HAF in response to any dose of dobutamine. Obstructive jaundice attenuated or completely abolished the PVF-increasing effect of dopamine, whereas it did not significantly alter the effect of dobutamine on hepatic blood flow. In dogs with obstructive jaundice, dopamine at 16 g/kg per min produced a decrease of 17±3% in PVF. These findings suggest that dobutamine is more effective than dopamine for increasing hepatic blood flow in patients with obstructive jaundice.     

Hepatic Blood Flow after Canine Portasystemic Shunting

Effects of portasystemic shunting on total hepatic blood flow (THBF) were evaluated in mongrel dogs with 35 and 50µ radioactive microspheres. THBF was measured prior to shunting and 1 hour and 3 weeks after surgery. Using systemic and pulmonary artery catheters, pertinent hemodynamic variables were also measured. In sham-operated dogs (n = 5), there were no significant changes in the hemodynamic parameters or the components of THBF during the experiment. After end-to-side shunting (n = 7), animals experienced a significant, permanent fall in hepatopetal portal blood flow (HABF). In contrast, dogs with side-to-side shunts (n = 7) exhibited a transient, significant increase in HABF 1 hour after surgery. Although the shunt eliminated HPBF, the rise in HABF prevented a significant, immediate fall in THBF. Three weeks after surgery, however, HABF had returned to the baseline range, and THBF was significantly lower than the preshunt value. Dogs with H-graft mesocaval shunts (n = 5) also exhibited a transient, significant rise in HABF 1 hour after surgery. Since HPBF did not fall substantially, THBF at this time was significantly higher than the baseline value. Three weeks after surgery, HABF had fallen to the baseline range, but THBF was not significantly different from the preshunt level. In animals with distal splenorenal shunts (n = 11), there was no significant change in HABF after shunting. Both HPBF and THBF were transiently, significantly reduced immediately after surgery, but three weeks later neither parameter was significantly lower than the preshunt values. There were no significant, persistent changes in the systemic perfusion pressures or flows in the shunted groups. These experiments demonstrate that the reported increase in HABF following portasystemic shunting is dependent on the type of shunt and, if it occurs, is a transient phenomenon. Hence, immediate postoperative changes in hemodynamic variables or hepatic blood flows do not necessarily reflect long-term patterns. In the normal dog, total portasystemic shunting produces a permanent, significant decrease in THBF, whereas selective shunting maintains THBF in the near-normal range.     

The postoperative effects of halothane versus isoflurane on hepatic artery and portal vein blood flow in humans

Animal studies have shown that halothane decreases total hepatic blood flow (THBF) by reducing both arterial (HABF) and portal (PVBF) inflow, whereas isoflurane appears to preserve them. In this study we assessed the effect of halothane and isoflurane on HABF and PVBF in surgical patients by using the pulsed Doppler technique. A validation study was conducted in six cynomolgus monkeys to compare the values of THBF obtained by the pulsed Doppler and indocyanine green clearance methods. Subsequently, six patients (ASA status I and II) undergoing elective open cholecystectomy were studied after surgery by using implanted pulsed Doppler probes. THBF and liver flow partition were compared during 1% halothane and 1.5% isoflurane (end-tidal concentrations). In the animal study, there was good agreement between the techniques (Bland and Altmann representation). In flunitrazepam-anesthetized patients, THBF was 1120 +/- 284 mL/min. Compared with this baseline and for a similar mean arterial blood pressure decrease (10%), THBF was maintained with isoflurane, whereas it decreased by 36% (P < 0.05) under halothane. With isoflurane, PVBF increased (25%; P = 0.067) with a maintained HABF. With halothane, both PVBF (-44%; P < 0.05) and HABF (-20%; P < 0.05) were reduced. Halothane acted mainly as a vasoconstrictor of the hepatic circulation, whereas isoflurane was a vasodilator, confirming the beneficial effect of isoflurane on hepatic oxygen supply. IMPLICATIONS: Volatile anesthetics may alter liver circulation with serious adverse effects. Using implanted pulsed Doppler probes in six anesthetized patients, we showed that halothane acted mainly as a vasoconstrictor of the liver vascular bed, whereas isoflurane was a vasodilator, confirming the beneficial effect of isoflurane on liver oxygen supply.     

Effects of side-to-side mesocaval shunt, pericardial devascularization, and a combined procedure in cirrhotic rats

In this study, side-to-side mesocaval shunt (MCS-SS), pericardial devascularization (PCDV), and combined operation of the two procedures were performed in 3 groups of thioacetamide induced liver cirrhotic of rats. Portal and hepatic hemodynamics were investigated on a period of six weeks postoperation, and glucagon concentration in portal vein (PV) and inferior vena cava (IVC) was measured before and six weeks after the surgery. It was found that following PCDV, free portal pressure (FPP) was initially elevated without an increase of total hepatic blood flow (THBF) within four weeks, then both FPP and THBF were shown to decrease on the sixth week. After MCS-SS with a stoma diameter of 2.0mm, a 31% decrease of FPP (P less than 0.05) and a 23% decrease of THBF (P less than 0.05) were observed, though the portal blood flow remained hepatopetal and hyperglucagonemia in PV was not changed. After combined procedure there was a greater decrease of FPP and THBF than that after MCS-SS, and the concentration of glucagon in PV was decreased without any change of its content in IVC.     

Noncirrhotic portal vein thrombosis. Physiology before and after shunts.

Controversy exists concerning the proper therapy for bleeding gastroesophageal varices secondary to noncirrhotic portal vein thrombosis. Disparity of opinion exists regarding the significance of hepatic portal blood flow and the consequences of total portal-systemic shunts in this condition. One patient is presented who developed severe, crippling encephalopathy 20 years after a central splenorenal shunt. This was associated with loss of portal flow to the liver and marked nitrogen intolerance. Closure of the shunt resulted in restoration of hepatic portal flow via collateral veins (HPI 0.36), clearance of encephalopathy and return to near normal protein tolerance. An additional patient was studied with hyperammonemia and early suggestive signs of encephalopathy eight years following a mesocaval shunt. Four patients were evaluated before and after selective distal splenorenal shunts. All had "cavernous transformation" of the portal vein with angiographic evidence of portal flow to the liver. Postoperative angiograms revealed continued hepatic portal perfusion and a patent shunt in each patient. Radionuclide imaging postoperatively gave an estimated portal fraction of total hepatic blood flow (HPI) of .39 and .60 in two of the four patients. We conclude that 1) there is significant hepatic portal perfusion in noncirrhotic portal vein thrombosis (cavernous transformation), 2) loss of this hepatic portal flow following total shunts can lead to severe encephalopathy, 3) the selective distal splenorenal shunt maintains hepatic portal perfusion and is the procedure of choice when there is a patent splenic vein and surgical intervention is indicated.     

Liver circulation and oxygen metabolism during short time ligation and the hepatic artery in the dog

The changes of liver circulation and liver oxygen metabolism during and after one hour hepatic artery ligation (HAL) were studied in eight mongrel dogs. At the end of the HAL period total hepatic blood flow (THBF) was reduced from 115.6 +/- 5.5 ml/min . 100 g liver tissue to 68.0 +/- 3.7 ml/min . 100 g or 59% of the initial value. The portal venous blood flow was reduced from 83.1 +/- 3.4 to 58.8 +/- 3.7 ml/min . 100 or 82% of the initial value and the liver oxygen consumption was reduced from 4.1 +/- 0.2 ml/min . 100 g to 3.1 +/- 0.3 ml/min . 100 g or 76% of the initial value. The changes in portal venous blood flow and liver oxygen consumption were reversible following reopening of the hepatic artery. The clinical importance of a reduced portal venous blood flow and liver oxygen consumption following HAL and the possibilities to increase the portal venous blood flow are discussed.     

原位肝移植术中结扎门体分流静脉的临床研究

目的 通过原位肝移植术中结扎经CT确认的粗大的门体分流静脉,探讨结扎该分流静脉的临床意义.方法 根据天津市第一中心医院移植外科2007年1月1日至2008年8月1日原位肝移植术前三维CT检杳35例中,12例无门体分流静脉,23例存在明确的门体分流静脉,并应用门静脉血流仪在术中行门静脉血流量测定,根据测量结果,其中7例未行分流静脉结扎,16例行门体分流静脉结扎.结果 本组中12例无门体静脉分流者的门静脉血流量是(1101±70)ml/min.23例有门体分流静脉中,7例门静脉血流量>1000 ml/min者未行分流静脉结扎,16例血流馈<1000 ml/min者行分流静脉结扎.16例结扎前后门静脉血流量分别是(657±112) ml/min和(1136±161) ml/min,结扎前后门静脉血流量相比差异有统计学意义(P<0.05).本组23例均获得随访,其中19例正常存活,移植物功能良好,血流正常.有2例术后门静脉血栓复发(经抗凝治疗后好转),其中1例出现间断性意识障碍,血氨水平波动在126～194 mmol/L之间,给予降血氨治疗后好转.2例在术后3个月内死亡,其中1例在术后1.5个月因肺部曲霉菌感染导致呼吸功能衰竭死亡,另1例在术后2个月因移植物功能不良导致肝功能衰竭而死亡. 结论原位肝移植术中结合三维CT扫描血管重建及血流动力学数据,结扎门体分流静脉是有意义的.