Functional significance of hepatic arterial flow reserve in patients with cirrhosis

Intravoxel incoherent motion diffusion weighted imaging for preoperative evaluation of liver regeneration after hepatectomy in hepatocellular carcinoma

OBJECTIVES

To explore whether intravoxel incoherent motion (IVIM) parameters could evaluate liver regeneration preoperatively.

METHODS

A total of 175 HCC patients were initially recruited. The apparent diffusion coefficient, true diffusion coefficient (D), pseudodiffusion coefficient (D*), pseudodiffusion fraction (f), diffusion distribution coefficient, and diffusion heterogeneity index (Alpha) were measured by two independent radiologists. Spearman's correlation test was used to assess correlations between IVIM parameters and the regeneration index (RI), calculated as 100% × (the volume of the postoperative remnant liver - the volume of the preoperative remnant liver) / the volume of the preoperative remnant liver. Multivariate linear regression analyses were used to identify the factors for RI.

RESULTS

Finally, 54 HCC patients (45 men and 9 women, mean age 51.26 ± 10.41 years) were retrospectively analyzed. The intraclass correlation coefficient ranged from 0.842 to 0.918. In all patients, fibrosis stage was reclassified as F0-1 (n = 10), F2-3 (n = 26), and F4 (n = 18) using the METAVIR system. Spearman correlation test showed D* (r = 0.303, p = 0.026) was associated with RI; however, multivariate analysis showed that only D value was a significant predictor (p < 0.05) of RI. D and D*showed moderate correlations with fibrosis stage (r = -0.361, p = 0.007; r = -0.457, p = 0.001). Fibrosis stage showed a negative correlation with RI (r = -0.263, p = 0.015). In the 29 patients who underwent minor hepatectomy, only the D value showed a positive association (p < 0.05) with RI, and a negative correlation with fibrosis stage (r = -0.360, p = 0.018). However, in the 25 patients who underwent major hepatectomy, no IVIM parameters were associated with RI (p > 0.05).

CONCLUSIONS

The D and D* values, especially the D value, may be reliable preoperative predictors of liver regeneration.

KEY POINTS

• The D and D* values, especially the D value, derived from IVIM diffusion-weighted imaging may be useful markers for the preoperative prediction of liver regeneration in patients with HCC. • The D and D* values derived from IVIM diffusion-weighted imaging show significant negative correlations with fibrosis, an important predictor of liver regeneration. • No IVIM parameters were associated with liver regeneration in patients who underwent major hepatectomy, but the D value was a significant predictor of liver regeneration in patients who underwent minor hepatectomy.

Effect of ET-A blockade on portal pressure and hepatic arterial perfusion in patients with cirrhosis: A proof of concept study

BACKGROUND/AIM

Endothelin causes vasoconstriction via the endothelin-A receptor (ET-A) in the intrahepatic circulation in cirrhosis and its increase leads to portal hypertension. The aim of the study was to investigate the acute effect of a selective ET-A antagonist in patients with portal hypertension and cirrhosis.

METHODS

Proof-of-concept study with two different substudies: (a) local intrahepatic administration of the ET-A antagonist BQ 123 and (b) systemic oral administration of the ET-A antagonist Ambrisentan. Portal pressure was determined by hepatic venous pressure gradient (HVPG, both substudies) and hepatic arterial blood flow (HABF) by intra-arterial Doppler measurements (substudy 1) before and under the ET-A antagonist. Systemic haemodynamic parameters were measured in substudy 2.

RESULTS

Twelve patients (Child-Pugh [CP] B/C n = 7/5) were included in substudy 1 and 14 patients (CP A/B/C n = 4/6/4) in substudy 2. The relative decrease in HVPG was -12.5% (IQR: -40% to 0%; P = .05) in substudy 1 and -5.0% (IQR: -11.5% to 0%; P = .01) in substudy 2. Substudy 1 revealed higher decrease in HVPG in CP B patients. HABF increased significantly and patients without portal pressure decrease showed a higher increase of HABF. Substudy 2 showed a slight decrease in the mean arterial pressure without changes of other systemic haemodynamic parameters.

CONCLUSION

Administration of a selective ET-A antagonist decreases the portal pressure in cirrhotic patients. This decrease was higher in CP B patients and the non-responders showed a higher increase in hepatic arterial flow. Selective ET-A antagonists might be a future treatment option in patients with portal hypertension.

Successful Urgent Living Donor Liver Transplantation for Massive Liver Necrosis Accompanied by Nonocclusive Mesenteric Ischemia in a Biliary Atresia Infant: A Case Report

BACKGROUND

Treatment options for patients presenting with life-threatening splanchnic ischemia, including that of the intestine and liver, could previously only receive salvage surgery and attempted medical revascularization. We propose that urgent liver transplantation (LT) for acute liver failure (ALF) due to massive liver necrosis should be considered as a life-saving treatment. We successfully performed urgent living donor LT for nonocclusive hepatic ischemia accompanied by nonocclusive mesenteric ischemia (NOMI).

CASE

An 11-month-old boy with biliary atresia whose jaundice was re-elevated after Kasai portoenterostomy underwent cysto-jejunostomy. Three hours after the uneventful operation, tachycardia, hypotension, and unconsciousness suddenly occurred. Computed tomography revealed whole-liver and massive splenic and focal intestinal ischemia without any vessel occlusion. Urgent LT was performed on postoperative day 3 because intensive therapies, including prostaglandin E1 administration, blood transfusion, and continuous hemodiafiltration, were not effective and the patient had developed life-threatening bradycardia and hypotension. Intraoperative findings included whole-liver necrosis and splenic ischemia and segmental ileal necrosis without any vessel thrombus. LT and necrotic intestinal resections by end-to-end anastomosis were performed. Massive liver necrosis with Gram-positive cocci was histopathologically identified, indicating bacterial translocation due to NOMI. The post-LT course was uneventful, and the neurologic outcomes were uncomplicated.

CONCLUSIONS

Urgent LT was successfully completed for ALF with NOMI. LT is the sole treatment for the refractory ALF, and undelayed determination is important to rescue.

Hepatectomy combined with microwave ablation of the spleen for treatment of hepatocellular carcinoma complicated with splenomegaly: A retrospective study

The present retrospective study aimed to investigate the mid-term safety and efficacy of hepatectomy combined with microwave ablation of the partial spleen for treatment of liver cancer complicated with hypersplenism. A retrospective analysis was performed on 23 patients who underwent hepatectomy combined with microwave ablation of the partial spleen for liver cancer, complicated with hypersplenism that was secondary to cirrhosis. The splenic and ablated volumes were calculated according to a contrast-enhanced computed tomography scan prior to and 2 weeks after the operation. Complete blood count and liver function tests were examined prior to and following the surgery, and complications and changes in the blood tests were monitored for 6 months. Over this period of investigation, the splenic volume was reduced by a mean value of 34.0%. The levels of serum alanine aminotransferase and aspartate aminotransferase were increased on the first day after the operation (P<0.05), although they recovered to the normal level within 1 week (P<0.05). The total level of bilirubin increased slightly, along with moderately decreased levels of albumin and cholinesterase on the first day, although these changes were not significant compared with the baseline (P>0.05). The white blood cell count was persistently significantly higher compared with the baseline over the course of the 6 months (P>0.05). The platelet count did not increase significantly for the first week after the operation (P>0.05); however, it was revealed to be significantly increased 1 month after the surgery (P<0.05). No significant complications were occurred during the follow-up period. In conclusion, hepatectomy combined with microwave ablation of the spleen was demonstrated to be a safe and effective procedure for patients with liver cancer and hypersplenism in the mid-term.

Radiologic evaluation of portal steal phenomenon in recipients of liver transplantation

It is important to maintain adequate portal flow and to prevent the detrimental effect of portosystemic shunt in recipients following liver transplantation. The purpose of this article is to present a comprehensive review of portosystemic shunts and to illustrate such phenomenon demonstrated on radiologic studies such as Doppler ultrasound, computed tomography, and portogram. It is important for radiologists to be aware of such phenomenon not only in preoperative evaluation of the recipients but also in postoperative screening to detect recurrence of the phenomenon.

Increased Hepatic Arterial Blood Flow Measured by Hepatic Perfusion Index in Hepatosplenic Schistosomiasis: New Concepts for an Old Disease

BACKGROUND

Portal vein obstructive lesions associated with hypertrophy of the hepatic artery territory are observed in Schistosoma mansoni schistosomiasis. Liver perfusion scintigraphy is a method used for evaluation of hepatic perfusion changes in liver diseases. It has been suggested that, like in cirrhosis, where compensatory increase in perfusion through the hepatic artery is documented, perfusion changes occur in hepatosplenic schistosomiasis (HSS).

AIMS

This study aims to determine changes in liver hemodynamics using hepatic perfusion scintigraphy and correlate them with clinical and laboratory variables and ultrasound findings in HSS.

METHODS

Nineteen patients with schistosomiasis underwent ultrasound evaluation of degree of liver fibrosis, splenic length, and splenic and portal vein diameter, digestive endoscopy, and quantification of platelets. Subsequently, perfusion scintigraphy with measurement of hepatic perfusion index (HPI) was performed.

RESULTS

It was observed that patients with hepatosplenic schistosomiasis had significantly higher HPI compared with normal individuals (p = 0.0029) and that this increase correlated with splenic length (p = 0.038) and diameter of esophageal varices (p = 0.0060). Angioscintigraphy showed high accuracy for predicting presence of large esophageal varices.

CONCLUSIONS

Angioscintigraphy could show that patients with HSS had increased HPI, featuring greater liver "arterialization," as previously described for cirrhotic patients. Correlations were also observed between HPI and longitudinal splenic length, caliber of esophageal varices, caliber of portal vein, and blood platelet count. Angioscintigraphy is a promising technique for evaluation of hepatosplenic schistosomiasis.

Comparison of the ability of the PDD-ICG clearance test, CTP, MELD, and MELD-Na to predict short-term and medium-term mortality in patients with decompensated hepatitis B cirrhosis

OBJECTIVE

Various methods, including the indocyanine green (ICG) clearance test, the Child-Turcotte-Pugh score (CTP), model for end-stage liver disease (MELD), and MELD combined with serum sodium concentration (MELD-Na), have been used widely in liver function evaluation in patients with end-stage liver disease. In this study, we compared the ability of these methods to predict mortality in patients with decompensated hepatitis B cirrhosis.

METHODS

A total of 98 patients with decompensated hepatitis B cirrhosis were included in this study and followed up for 12 months. The ICG-derived measurements (ICG-PDR, ICG-R15, EHBF), CTP, MELD, and MELD-Na were obtained within 2 days after patients' admission and patients' survival at 1, 3, 6, and 12 months was recorded. Receiver operating curve was used to evaluate the ability of these methods to predict mortality in these patients with decompensated hepatitis B cirrhosis.

RESULTS

At 1 month, 3 months, 6 months and 12 months, the cumulative number of deaths and liver transplant recipients was 12 (12.2%), 17 (17.3%), 21 (21.4%) and 25 (25.5%), respectively. The ICG-derived measurements, CTP, MELD, and MELD-Na of nonsurvivors were significantly different compared with that in survivors. All methods yielded viable values in predicting short-term and medium-term prognosis for patients with decompensated hepatitis B cirrhosis, with most area under the curve exceeding 0.8. Moreover, the ICG-derived measurements showed a significant correlation with that of CTP, MELD, and MELD-Na.

CONCLUSION

All four methods, ICG clearance test, CTP, MELD, and MELD-Na, provided reliable prediction of mortality in patients with decompensated hepatitis B cirrhosis for both short-term and medium-term prognosis.

Hepatic arterial vasodilation is independent of portal hypertension in early stages of cirrhosis

Introduction

The compensatory increase in hepatic arterial flow with a decrease in portal venous flow is known as the hepatic arterial buffer response. In cirrhosis with elevated portal pressure, the vascular resistance of the hepatic artery is decreased. Whether this lower resistance of the hepatic artery is a consequence of portal hypertension or not remains unknown.

Study Aim

The aim of the study was to investigate the hepatic arterial resistance and response to vasoconstriction in cirrhosis without portal hypertension (normal portal resistance).

Methods

Cirrhosis was induced by CCl₄-inhalation for 8 weeks (8W, normal portal resistance) and for 12–14 weeks (12W, elevated portal resistance). Bivascular liver perfusion was performed at 8W or 12W and dose response curves of methoxamine were obtained in the presence or absence of LNMMA (nitric oxide synthase blocker). Vascular resistances of the hepatic artery (HAR), portal vein (PVR) and sinusoids (SVR) were measured. Western Blot (WB) and Immunohistochemistry (IHC) were done to measure eNOS and HIF 1a expression.

Results

HAR in both groups of cirrhotic animals (8W and 12W) were lower compared to controls. Dose response curves to methoxamine revealed lower HAR in both cirrhotic models (8W and 12W) regardless the magnitude of portal resistance. LNMMA corrected the dose response curves in cirrhosis (8W and 12W) to control. WB and IHC show increased protein expression of eNOS and HIF1a in 8W and 12W.

Conclusion

Hepatic arterial resistance is decreased in cirrhosis independent of portal resistance. Vasodilation of the hepatic artery in cirrhosis seems to be influenced by hypoxia rather than increase in portal resistance. Nitric oxide is the main vasodilator.

Beyond a broken heart: circulatory dysfunction in the failing Fontan

The role of ventricular dysfunction in late morbidity and mortality of univentricular hearts has been described previously. However, a significant proportion of adult Fontan patients who die or require heart transplantation do so with preserved ventricular function. The clinical deterioration in patients who have undergone Fontan palliation requires a broader view of circulatory dysfunction, one that takes into account the complex interaction of regulatory systems affecting hepatic, renal, and pulmonary blood flow, in addition to cardiac function. This review focuses primarily on the pathophysiology of multiple organ involvement in this circulatory dysfunction, with particular focus on the consequences of hepatic dysfunction and portal hypertension. The authors discuss hepatic perfusion, both in health and disease, and review the current understanding of liver histopathology and liver disease in adult Fontan patients and similar clinicopathologic states. They compare and contrast features of postsinusoidal portal hypertension with more typical adult cirrhotic disease. Finally, they delineate the related effects of portal hypertensive physiology on the systemic and pulmonary vasculature, the kidney, and the heart itself and discuss how these changes affect the care of the adult Fontan patient.

Indocyanine green retention test as a noninvasive marker of portal hypertension and esophageal varices in compensated liver cirrhosis

Noninvasive markers would be useful for the assessment of portal hypertension (PH) and esophageal varices (EV) in patients with cirrhosis. The aim of our study was to evaluate the performance of the indocyanine green (ICG) retention test as a noninvasive marker of PH and EV, measured against the gold standards (hepatic venous pressure gradient [HVPG] measurement and upper endoscopy). We prospectively enrolled patients with compensated cirrhosis referral to our unit. All patients underwent laboratory tests, abdominal ultrasound, upper gastrointestinal endoscopy, HVPG measurement, and the ICG 15-minute retention (ICG-r15) test. We evaluated the sensitivity and specificity of the ICG retention test and other noninvasive tools for the diagnosis of PH and EV. Ninety-six consecutive Child-Pugh A patients (67 male and 29 female; 60.3 ± 11.8 years of age) were enrolled. Seventy-four patients had clinically significant portal hypertension (CSPH), of whom 59 had severe portal hypertension (SPH). ICG-r15 and Lok index were independently related to the presence of both CSPH and SPH, whereas ICG-r15 and INR were related to EV. ICG-r15 values (<6.7% and <6.9%, respectively) were able to rule out the presence of CSPH and SPH (LR(-) 0.15 and 0.14); ICG-r15 <10% provided a 97.8% sensitivity (LR(-) 0.042) for the exclusion of EV and a 100% sensitivity (LR(-) 0.0) for large EV.

CONCLUSION

The ICG-r15 test is an effective tool for assessment of PH in patients with compensated cirrhosis. Although this would not replace endoscopy, the ICG-r15 appears able to identify patients with advanced liver disease in which endoscopy is mandatory as well as rule out the presence of EV in patients with compensated cirrhosis.

Assessment of hepatic hemodynamics using high-frequency ultrasound in normal rats

AIM: To detect hepatic hemodynamic parameters in normal rats to provide a basis for further monitoring and evaluation of liver diseases in rats.

METHODS: One hundred Sprague-Dawley (SD) rats were used. A 5-12 MHz high-frequency linear transducer was applied to obtain liver ultrasonograms and measure the diameter and maximum velocity of the portal vein, the peak systolic velocity, end diastolic velocity and resistance index of the proper hepatic artery.

RESULTS: The portal vein of rats was well demonstrated by high-frequency ultrasound. The test showed that the diameter of the portal vein of normal SD rats was around 0.18 cm ± 0.03 cm, the maximum velocity of the portal vein was around 16.21 cm/s ± 3.86 cm/s, and the peak systolic velocity, end diastolic velocity and resistance index of the proper hepatic artery were around 57.60 cm/s ± 15.41 cm/s, 26.46 cm/s ± 10.96 cm/s and 0.54 ± 0.13, respectively.

CONCLUSION: High-frequency Doppler ultrasonography allows obtaining clear portal vein ultrasonograms and the hemodynamic parameters of the portal vein and hepatic artery in rats, representing an effective method for monitoring hepatic hemodynamic changes in experimental rats.

Preliminary results of supra-hepatic intraaortic perfusion with nitroglycerin for patients with significant hepatic dysfunction

BACKGROUND

Preoperative hepatic dysfunction is a risk factor for postoperative fulminant hepatic failure and death. We noted persistent hepatic artery vasospasm in patients dying of postoperative hepatic failure. We hypothesized that an intra-aortic vasodilator such as nitroglycerin could attenuate vasospasm and prevent hepatic failure.

METHODS

Nineteen consecutive patients with significant preoperative hepatic dysfunction underwent cardiac surgery using cardiopulmonary bypass with continuous infusion of intra-aortic nitroglycerin via a catheter placed above the celiac axis. Serial hepatic artery Doppler studies were done perioperatively with and without the nitroglycerin infusion on. Hepatic artery Doppler, hepatic artery size, alterations in liver function and serum creatinine, and outcomes were noted. Survival was compared to the Euroscore and a hepatic risk score that was based on a historical cohort and reported literature.

RESULTS

One patient could not be weaned off cardiopulmonary bypass. In the remaining 18 patients, reversible hepatic arterial vasospasm was noted, and this persisted at 24 hours in 12 patients and 48 hours in 7 patients. All patients had resolution of vasospasm at 72 hours. Serial paired hepatic artery diameter measurements showed a significant difference (P < .001). There was a significant reduction in mortality (5.2 %) compared to historical control and predicted mortality (logistic Euroscore 37.4%, P = .023). None of the survivors had a significant alteration in hepato-renal function.

CONCLUSION

Intra-aortic nitroglycerin can attenuate hepatic arterial vasospasm induced by cardiopulmonary bypass and preserve hepatic function. This may reduce the risk associated with cardiopulmonary bypass and surgery in patients with liver dysfunction.

The blood concentration and organ distribution of haloperidol at therapeutic and toxic doses in severe fatty liver disease

The aim of this study was to investigate the difference between the pharmacokinetics of haloperidol in normal rats and in rats with fatty liver disease. A therapeutic dosage (0.1 mg/kg) and a toxic dose (15 mg/kg) of haloperidol were administrated to normal 9-week-old male rats or those with severe fatty liver disease, and the blood concentration of haloperidol was determined 15 min, 1, 2, and 3 h following haloperidol administration. The concentration of haloperidol in the organs was determined 1, 2, and 3 h after the haloperidol administration. Additionally, the volume of the portal vein blood flow was measured 3 h after haloperidol administration. When given at the therapeutic dosage, the concentrations of haloperidol in both the blood and organs of the rats with fatty liver disease were significantly higher than those in the normal rats. However, when given at the toxic level, the blood and organ haloperidol concentrations 1 h after administration tended to be lower in the rats with fatty liver disease than those in the normal rats; these lower haloperidol levels returned to be the levels in the normal rats 3 h after the administration of haloperidol. The volume of the portal vein blood flow significantly increased following the toxic haloperidol dose as compared with the volume pre-administration and following the therapeutic haloperidol dose in the normal rats. However, the volume did not change after the toxic or the therapeutic dose of haloperidol compared with pre-administration in rats with severe fatty liver disease, although it was significantly higher than in the normal rats. The pathway for haloperidol metabolism might have been saturated before the administration of haloperidol in rats with fatty liver disease; thus, it is possible that the blood concentration of haloperidol tends to be much higher in individuals with severe fatty liver disease than in those with normal livers in an inverse proportion to the dosage of haloperidol.

Transjugular intrahepatic portosystemic shunt-related complications and practical solutions

Despite the clinical complexity of patients with severe liver disease and the technical demands associated with the creation of a transjugular intrahepatic portosystemic shunt (TIPS), the major complication rate of this procedure is less than 5%. Delayed recognition and treatment of complications related to TIPS can have life-threatening consequences. This article provides an overview of the spectrum of periprocedural and delayed complications related to the performance of TIPS and offers the reader pearls for both avoiding and managing those complications.

A Laparoscopic Splenectomy Allows the Induction of Antiviral Therapy for Patients with Cirrhosis Associated with Hepatitis C Virus

It is difficult to treat patients with cirrhosis-associated hepatitis C with pegylated interferon (PEG-IFN) and ribavirin because of thrombocytopenia-related hypersplenism. Both safety and clinical efficacy were retrospectively analyzed for patients who underwent a laparoscopic splenectomy (LS) from January 2003 to December 2007. A total of 35 patients with cirrhosis associated with hepatitis C virus had LS for thrombocytopenia before PEG-IFN and ribavirin therapy, and all patients had thrombocytopenia, which was a contraindication for antiviral therapy. The hepatopathy was Child A in 24 patients, Child B in 10 patients, and Child C in one patient. All 35 patients increased platelet count from 48,000 ± 15,000 to 155,000 ± 55,000/μl ( P < 0.0001) after LS. The median hospital stay and blood loss were 13.0 days (range, 8 to 57 days) and 342.0 mL (range, 5 to 2350 mL). There was no postoperative death. Twenty-nine (83%) patients had PEG-IFN and ribavirin therapy after LS; 18 had complete therapy and 11 had partial therapy. Of these, nine had a sustained virologic response. A laparoscopic splenectomy for patients with cirrhosis associated with hepatitis C virus can be performed safely and allows induction of antiviral treatment.

Cardiovascular diseases and the liver

The dual blood supply of the liver, originating from the portal vein and the hepatic artery, makes it relatively resistant to minor circulatory disturbances. However, hepatic manifestations of common cardiovascular disorders are frequently encountered in both the inpatient and outpatient setting. Beginning with the macro- and microcirculation of the liver, this article reviews the pathophysiology of hepatic blood flow and gives a detailed appraisal of ischemic hepatitis, congestive hepatopathy, and other less common hepatic conditions that arise when cardiovascular function is impaired.

Regulation of hepatic blood flow: The hepatic arterial buffer response revisited

The interest in the liver dates back to ancient times when it was considered to be the seat of life processes. The liver is indeed essential to life, not only due to its complex functions in biosynthesis, metabolism and clearance, but also its dramatic role as the blood volume reservoir. Among parenchymal organs, blood flow to the liver is unique due to the dual supply from the portal vein and the hepatic artery. Knowledge of the mutual communication of both the hepatic artery and the portal vein is essential to understand hepatic physiology and pathophysiology. To distinguish the individual importance of each of these inflows in normal and abnormal states is still a challenging task and the subject of ongoing research. A central mechanism that controls and allows constancy of hepatic blood flow is the hepatic arterial buffer response. The current paper reviews the relevance of this intimate hepatic blood flow regulatory system in health and disease. We exclusively focus on the endogenous interrelationship between the hepatic arterial and portal venous inflow circuits in liver resection and transplantation, as well as inflammatory and chronic liver diseases. We do not consider the hepatic microvascular anatomy, as this has been the subject of another recent review.

Noncirrhotic human nonalcoholic fatty liver disease induces portal hypertension in relation to the histological degree of steatosis

INTRODUCTION

We earlier showed in an animal model that steatosis, in the absence of fibrosis or inflammation, induces a significant rise in portal pressure. The relevance of these findings for human pathology is unknown till date.

AIMS

To study portal pressure in nonalcoholic fatty liver disease patients and to identify factors possibly related to steatosis-induced changes in liver haemodynamics.

MATERIALS AND METHODS

Patients presenting with a problem of overweight and with noninvasive signs of liver involvement were proposed for transjugular liver biopsy. The biopsy was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network scoring system.

RESULTS

Fifty consecutive patients were studied. Mean age was 47.9 ± 13.6 years; 31 (62%) of them were female. Hepatic venous pressure gradient (HVPG) was normal in 27 patients (54%), borderline (5 mmHg) in nine (18%) and elevated in 14 patients (28%). For further analysis those with a HVPG of 5 mmHg were considered normal (group 1). HVPG was 8.8 ± 2.6 mmHg in those with an elevated HVPG (group 2) versus 3.4 ± 1.2 mmHg in group 1 (P < 0.0001). In both the groups, only one patient had cirrhosis; 26 of 36 (group 1) and nine of 14 patients (group 2) had fibrosis score 0. Fibrosis score was not significantly different (P = 0.530). Perisinusoidal fibrosis score was not significantly different (P = 0.186). Steatosis was the only histological feature that significantly differed between the groups (P = 0.016). The degree of steatosis (P = 0.010) was the only independent predictor of the presence of portal hypertension.

CONCLUSION

Human nonalcoholic fatty liver disease can, even in the absence of significant fibrosis, induce portal hypertension, correlated with the severity of the steatosis.

A distinct nitric oxide and adenosine A1 receptor dependent hepatic artery vasodilatatory response in the CCl-cirrhotic liver

Increase of portal venous vascular resistance is counteracted by decrease of hepatic arterial vascular resistance (hepatic arterial buffer response). This process is mediated by adenosine in normal livers. In cirrhosis, hepatic arterial vascular resistance is decreased but the involvement of adenosine in this process is unknown. The aim of our study was to identify the signalling pathway responsible for the decreased hepatic arterial resistance in cirrhotic livers.

METHODS

Cirrhosis was induced by CCl(4). Using a bivascular liver perfusion dose-response curves to adenosine of the HA were performed in the presence and the absence of pan-adenosine blocker (8-SPT), A1 blocker (caffeine) or nitric oxide synthase-blocker (l-NMMA) after preconstriction with an alpha1-agonist (methoxamine). Western blot of the HA were used to measure the density of the A1 and A2a receptors.

RESULTS

Adenosine caused a dose dependent relaxation of the hepatic artery of both cirrhotic and control animals that were blocked in both groups by 8-SPT (P<0.02). The response to adenosine was greater in cirrhotic rats (P=0.016). Both l-NMMA (P=0.003) and caffeine reduced the response to adenosine in cirrhotic but not in control animals. Western blot analysis showed a higher density of A1 and a lower density of A2a receptor in cirrhotic animals (P<0.05).

CONCLUSION

The adenosine-induced vasodilatation of the HA is increased in cirrhotic rats suggesting a role for adenosine-NO in the decreased hepatic arterial vascular resistance found in cirrhosis. This significantly greater response in cirrhosis by the A1 receptor follows the same pathway that is seen in hypoxic conditions in extra-hepatic tissues.

Non-alcoholic steatohepatitis induces non-fibrosis-related portal hypertension associated with splanchnic vasodilation and signs of a hyperdynamic circulation in vitro and in vivo in a rat model

INTRODUCTION

Steatosis, without fibrosis, may lead to changes in liver blood flow, which are poorly understood, and to date have not been correlated to portal pressure and related haemodynamics.

AIMS

To study the temporal relation between progressive steatosis, portal pressure, systemic haemodynamics, vascular responsiveness, mesenteric and portal blood flow in methionine-choline-deficient diet (MCDD)-fed rats.

METHODS

Male Wistar rats fed the MCDD were examined at week (w) 0-1-2-3-4-5-6-7-8, respectively, including systemic haemodynamics and portal pressure. At w0-4-8, in vivo blood flow was measured in the portal vein and the superior mesenteric artery. Dose-response curves to phenylephrine (PE) were established in abdominal aortic rings.

RESULTS

Histology showed 100% steatosis from w3 on. Fibrosis was absent. Significant inflammation was nearly absent upon w4. Portal pressure slightly increased at w2, reached a maximum at w4 [9.4 +/- 0.3 vs 2.9 +/- 0.6 mmHg at w0 (P=0.003)] and remained stable upon w8. Mean arterial blood pressure (MABP) decreased from w2 on [98.7 +/- 5.7 mmHg on w4 compared with 123.8 +/- 1.8 on w0 (P=0.002)]. Portal flow increased from 1.85 +/- 0.11 to 3.07 +/- 0.44 ml/min/100 g on w0 and w8 respectively (P=0.039). Mesenteric artery flow increased from 3.40 +/- 0.26 to 4.56 +/- 0.30 ml/min/100 g on w0 and w8 respectively (P=0.043). Vascular responsiveness to PE gradually decreased from 138 +/- 3% on w0 to 110 +/- 5% on w4 (P=0.013).

CONCLUSION

Steatohepatitis induces significant portal hypertension (PHT) in the absence of fibrosis, associated with an increase in mesenteric arterial and portal venous flow, arterial hyporesponsiveness to vasoconstrictors and a decrease in MABP, indicating the presence of splanchnic vasodilation and hyperdynamic circulation. These alterations resemble those seen in cirrhotic PHT.

The hepatic microcirculation: mechanistic contributions and therapeutic targets in liver injury and repair

The complex functions of the liver in biosynthesis, metabolism, clearance, and host defense are tightly dependent on an adequate microcirculation. To guarantee hepatic homeostasis, this requires not only a sufficient nutritive perfusion and oxygen supply, but also a balanced vasomotor control and an appropriate cell-cell communication. Deteriorations of the hepatic homeostasis, as observed in ischemia/reperfusion, cold preservation and transplantation, septic organ failure, and hepatic resection-induced hyperperfusion, are associated with a high morbidity and mortality. During the last two decades, experimental studies have demonstrated that microcirculatory disorders are determinants for organ failure in these disease states. Disorders include 1) a dysregulation of the vasomotor control with a deterioration of the endothelin-nitric oxide balance, an arterial and sinusoidal constriction, and a shutdown of the microcirculation as well as 2) an overwhelming inflammatory response with microvascular leukocyte accumulation, platelet adherence, and Kupffer cell activation. Within the sequelae of events, proinflammatory mediators, such as reactive oxygen species and tumor necrosis factor-alpha, are the key players, causing the microvascular dysfunction and perfusion failure. This review covers the morphological and functional characterization of the hepatic microcirculation, the mechanistic contributions in surgical disease states, and the therapeutic targets to attenuate tissue injury and organ dysfunction. It also indicates future directions to translate the knowledge achieved from experimental studies into clinical practice. By this, the use of the recently introduced techniques to monitor the hepatic microcirculation in humans, such as near-infrared spectroscopy or orthogonal polarized spectral imaging, may allow an early initiation of treatment, which should benefit the final outcome of these critically ill patients.

Adenosine induces loss of actin stress fibers and inhibits contraction in hepatic stellate cells via Rho inhibition

The Rho/ROCK pathway is activated in differentiated hepatic stellate cells (HSCs) and is necessary for assembly of actin stress fibers, contractility, and chemotaxis. Despite the importance of this pathway in HSC biology, physiological inhibitors of the Rho/ROCK pathway in HSCs are not known. We demonstrate that adenosine induces loss of actin stress fibers in the LX-2 cell line and primary HSCs in a manner indistinguishable from Rho/ROCK inhibition. Loss of actin stress fibers occurs via the A2a receptor at adenosine concentrations above 10 muM, which are present during tissue injury. We further demonstrate that loss of actin stress fibers is due to a cyclic adenosine monophosphate, protein kinase A-mediated pathway that results in Rho inhibition. Furthermore, a constitutively active Rho construct can inhibit the ability of adenosine to induce loss of actin stress fibers. Actin stress fibers are required for HSC contraction, and we demonstrate that adenosine inhibits endothelin-1 and lysophosphatidic acid-mediated HSC contraction. We propose that adenosine is a physiological inhibitor of the Rho pathway in HSCs with functional consequences, including loss of HSC contraction.

Liver cirrhosis: intravoxel incoherent motion MR imaging--pilot study

PURPOSE

To retrospectively evaluate a respiratory-triggered diffusion-weighted (DW) magnetic resonance (MR) imaging sequence combined with parallel acquisition to allow the calculation of pure molecular-based (D) and perfusion-related (D*, f) diffusion parameters, on the basis of the intravoxel incoherent motion (IVIM) theory, to determine if these parameters differ between patients with cirrhosis and patients without liver fibrosis.

MATERIALS AND METHODS

The institutional review board approved this retrospective study; informed consent was waived. IVIM DW imaging was tested on three alkane phantoms, on which the signal-intensity decay curves according to b factors were logarithmically plotted. Ten b factors (0, 10, 20, 30, 50, 80, 100, 200, 400, 800 sec/mm(2)) were used in patients. Patients with documented liver cirrhosis (cirrhotic liver group, n = 12) and patients without chronic liver disease (healthy liver group, n = 25) were included. The mean liver D, D*, and f values were measured and compared with the apparent diffusion coefficient (ADC) computed by using four b values (0, 200, 400, 800 sec/mm(2)). Liver ADC and D, f, and D* parameters were compared between the cirrhotic liver group and healthy liver group. Means were compared by using the Student t test.

RESULTS

Signal-intensity decay curves were monoexponential on phantoms and biexponential in patients. In vivo, mean ADC values were significantly higher than D in the healthy liver group (ADC = 1.39 x 10(-3) mm(2)/sec +/- 0.2 [standard deviation] vs D = 1.10 x 10(-3) mm(2)/sec +/- 0.7) and in the cirrhotic liver group (ADC = 1.23 x 10(-3) mm(2)/sec +/- 0.4 vs D = 1.19 x 10(-3) mm(2)/sec +/- 0.5) (P = .03). ADC and D* were significantly reduced in the cirrhotic liver group compared with those in the healthy liver group (respective P values of .03 and .008).

CONCLUSION

Restricted diffusion observed in patients with cirrhosis may be related to D* variations, which reflect decreased perfusion, as well as alterations in pure molecular water diffusion in cirrhotic livers.

Vasopressin decreases portal vein pressure and flow in the native liver during liver transplantation

Vasodilation due to impaired vascular tone is common in liver failure. Vasoconstrictor drugs are almost always required during the anhepatic phase of a liver transplant to maintain blood pressure unless venovenous bypass is employed. Arginine-vasopressin can be used as a vasoconstrictor instead of or in addition to norepinephrine for this purpose, but the effect of vasopressin on the portal vein pressure and flow in this setting is unknown. Portal vein pressure, portal vein blood flow, hemodynamic variables, and plasma vasopressin levels were measured in 16 patients during liver transplantation after ligation of the hepatic artery before and after a vasopressin infusion of 3.8 +/- 1.1 units/hour. Measurements were performed on the native liver prior to caval clamping. After vasopressin infusion, the portal vein pressure decreased significantly from 24.0 +/- 6.5 to 21.5 +/- 7.4 mm Hg [mean +/- standard deviation (SD), P = 0.006]. The portal vein blood flow also decreased (from 1.01 +/- 0.53 to 0.76 +/- 0.53 L/minute, mean +/- SD, P < 0.0001), as did the portal vein blood flow to cardiac output ratio (from 0.14 +/- 0.06 to 0.10 +/- 0.07, mean +/- SD, P < 0.0001). In conclusion, vasopressin significantly decreased portal vein pressure and flow of the native liver without decreasing cardiac output or intestinal perfusion in patients undergoing liver transplantations.

Nitric oxide administration restores the hepatic artery buffer response during porcine endotoxemia

The hepatic artery buffer response, which is lost during endotoxemia, plays a central role in the autoregulation of liver perfusion. A temporarily decreased synthesis of nitric oxide during early endotoxemia might be responsible for this dysfunction; hence exogenous administration of nitric oxide could reestablish the autoregulation of hepatic blood flow and help prevent hepatic damage later in septic shock. Fifteen pigs were treated with lipopolysaccharide +/- the nitric oxide donor nitroprusside-sodium via the portal vein. Hemodynamics were measured, and serum chemistry and liver biopsies for nitric oxide synthase expression were obtained. Lipopolysaccharide decreased arterial liver perfusion after 5 hours by 38% (p = .012), which was reversed by addition of nitroprusside (8%). Administration of nitroprusside preserved an increase of 28% in hepatic arterial upon portal vein flow reduction (p < .001). Nitroprusside maintained mRNA levels of constitutive nitric oxide synthase in liver tissue which were decreased by lipopolysaccharide (p = .026 vs. p = .114) and tempered the burst in inducible nitric oxide synthase expression at t = 3 hours. The early administration of the nitric oxide donor sodium nitroprusside during endotoxemia is able to reestablish the autoregulatory response of the hepatic artery following reduction of hepatic blood flow. This beneficial effect might help to prevent subsequent hepatic damage in the course of abdominal sepsis.

The role of hepatic arterial flow on portal venous and hepatic venous wedged pressure in the isolated perfused CCl4-cirrhotic liver

In cirrhosis, hepatic venous pressure gradient is used to measure portal venous and sinusoidal pressures, as well as drug-induced decreases of elevated pressures. The aim of this study was to investigate the influence of hepatic arterial flow (HAF) changes on portal venous perfusion (PVPP) and wedged hepatic venous pressure (WHVP). Normal and CCl4-cirrhotic rats were subjected to a bivascular liver perfusion with continuous measurements of PVPP, WHVP, and hepatic arterial perfusion pressure. Flow-pressure curves were performed with the use of different flows either through the portal vein (PVF: 20-32 ml/min) or HAF (5-15 ml/min). Increases in HAF lead to significant absolute and relative increases in PVPP (P = 0.002) and WHVP (P < 0.001). Absolute changes in HAF correlated to absolute changes in PVPP (cirrhosis: r = 0.64, P < 0.001; control: r = 0.67, P < 0.001) and WHVP (cirrhosis: r = 0.71, P < 0.001; control: r = 0.82, P < 0.001). Changes in PVPP correlated to changes in WHVP due to changes in PVF only in cirrhosis (r = 0.75, P < 0.001), whereas changes in HAF correlated in both cirrhosis (r = 0.92, P < 0.001) and control (r = 0.77, P < 0.001). In conclusion, increases and decreases in HAF lead to respective changes in PVPP and WHVP. This suggests a direct influence of HAF on PVPP and WHVP most likely due to changes in sinusoidal perfusion.

Two-year follow-up of splenic radiofrequency ablation in patients with cirrhotic hypersplenism: does increased hepatic arterial flow induce liver regeneration?

BACKGROUND

Hepatocyte hypoxia may be a mechanism determining abnormal tissue oxygenation and dysfunction of the cirrhotic liver. Since the introduction of radiofrequency ablation (RFA) for patients with cirrhotic hypersplenism, we observed a phenomenon of visible hepatic regeneration. This study aims to investigate the potential mechanism of RFA-induced liver regeneration, and the 2-year outcomes of splenic RFA.

METHODS

Forty patients who underwent splenic RFA for cirrhotic hypersplenism were followed for 24 months. Before and after RFA procedures, portal hemodynamics and liver and spleen volumes were measured by Doppler ultrasonography and computed tomography volumetry. Liver function tests and blood counts were also determined.

RESULTS

The splenic and portal venous flows decreased, but hepatic arterial flow (HAF) increased dramatically after the RFA procedure. Liver volumes at 3 month post-RFA increased compared to the baseline volumes (872 +/- 107 vs. 821 +/- 99 cm(3), P = .031). A correlation was found between maximum absolute values of liver volumes (triangle upliver volumes) and that of HAF (triangle upHAF) in Child-Pugh class A/B patients (r = 0.60; P < .001). Leukocyte and platelet counts, as well as liver function, improved substantially during the 2-year follow-up. Patients with > or = 40% of spleen volume ablated had better improvement of thrombocytopenia. No death or severe complications occurred.

CONCLUSIONS

RFA for cirrhotic hypersplenism is safe and efficacious. The increase in HAF as a result of splenic RFA may improve liver function and induce liver regeneration in cirrhotics, but further studies are necessary to clarify the underlying mechanisms.

Increased sinusoidal resistance is responsible for the basal state and endothelin-induced venoconstriction in perfused cirrhotic rat liver

The localization of increased intrahepatic vascular resistance and the segmental vascular responsiveness to endothelin-1 are not well known in liver cirrhosis. We determined the segmental vascular resistances and their response to endothelin-1 of isolated portally perfused bile duct ligation (BDL)-induced cirrhotic rat livers. The portal occlusion pressure (Ppo) and the hepatic venous occlusion pressure (Phvo) were obtained by analyzing the profiles of the portal (Ppv) and hepatic venous (Phv) pressures during the double occlusion maneuver of simultaneous occlusions of the inflow and outflow perfusion lines. From the pressure gradients among Ppv, Ppo, Phvo, and Phv, the portal-hepatic venous resistance was assigned to three segments of the portal [Rpv = (Ppv - Ppo)/blood flow (Q)], sinusoidal [Rsinus = (Ppo - Phvo)/Q] and hepatic venous [Rhv = (Phvo - Phv)/Q] resistances. Rsinus, but not Rpv or Rhv, was significantly greater in BDL livers than in sham livers. Endothelin-1 (0.1-1 nM) increased Rpv and Rsinus to a similar magnitude, but not Rhv, in both sham and BDL. At 3 nM, the responsiveness of Rpv was smaller in BDL than in sham, but that of Rsinus were similar between in BDL and sham. In conclusion, increased sinusoidal resistance accounts for increased intrahepatic resistance of BDL-induced liver cirrhosis. Endothelin-1 contracts portal veins and sinusoids, but not hepatic veins, in both sham and cirrhotic livers. Sinusoidal contractility to endothelin-1 is not impaired in cirrhotic livers.

Hemodynamics in the isolated cirrhotic liver

Increased intrahepatic resistance is the initial event to the increased portal pressure and development portal hypertension in cirrhosis. Narrowing of the sinusoids due to anatomic changes is the main component of the increased intrahepatic resistance. However, a dynamic component is also involved in the increased vascular tone in cirrhosis. The imbalance between the hyperresponsiveness and overproduction of vasoconstrictors (mainly endothelin-1 and cyclooxygenase-derived prostaglandins) and the hyporesponsiveness and impaired production of vasodilators [mainly nitric oxide (NO)] are the mechanisms responsible of the increased vascular tone in the sinusoidal/postsinusoidal area. In contrast, the vascular resistance in the hepatic artery, which is determined in the presinusoidal area, is decreased due to increased vasodilators (NO and adenosine). This suggests different availabilities of NO in the intrahepatic circulation with preserved production in the presinusoidal area and impaired production in the sinusoidal/postsinusoidal area.

Radiofrequency ablation for hypersplenism in patients with liver cirrhosis: a pilot study

Radiofrequency ablation is a relatively new technique used for local ablation of unresectable tumors. We investigated the feasibility and efficacy of radiofrequency ablation for hypersplenism and its effect on liver function in patients with liver cirrhosis and portal hypertension. Nine consecutive patients with hypersplenism due to cirrhotic portal hypertension underwent radiofrequency ablation in enlarged spleens. The ablation was performed either intraoperatively or percutaneously. Patients are followed up for over 12 months. After treatment, between 20% and 43% of spleen volume was ablated, and spleen volume increased by 4%-10.2%. White blood cell count, platelet count, liver function, and hepatic artery blood flow showed significant improvement after 1-year follow-up. Splenic vein and portal vein blood flow were significantly reduced. Only minor complications including hydrothorax (three of nine patients) and mild abdominal pain (four of nine patients) were observed. No mortality or other morbidity occurred. Radiofrequency ablation is a safe, effective, and minimally invasive approach for the management of splenomegaly and hypersplenism in patients with liver cirrhosis and portal hypertension. Increased hepatic artery blood flow may be responsible for sustained improvement of liver condition. Radiofrequency ablation may be used as a bridging therapy for cirrhotic patients waiting for liver transplantation.

Perfusion imaging of the liver: current challenges and future goals

Improved therapeutic options for hepatocellular carcinoma and metastatic disease place greater demands on diagnostic and surveillance tests for liver disease. Existing diagnostic imaging techniques provide limited evaluation of tissue characteristics beyond morphology; perfusion imaging of the liver has potential to improve this shortcoming. The ability to resolve hepatic arterial and portal venous components of blood flow on a global and regional basis constitutes the primary goal of liver perfusion imaging. Earlier detection of primary and metastatic hepatic malignancies and cirrhosis may be possible on the basis of relative increases in hepatic arterial blood flow associated with these diseases. To date, liver flow scintigraphy and flow quantification at Doppler ultrasonography have focused on characterization of global abnormalities. Computed tomography (CT) and magnetic resonance (MR) imaging can provide regional and global parameters, a critical goal for tumor surveillance. Several challenges remain: reduced radiation doses associated with CT perfusion imaging, improved spatial and temporal resolution at MR imaging, accurate quantification of tissue contrast material at MR imaging, and validation of parameters obtained from fitting enhancement curves to biokinetic models, applicable to all perfusion methods. Continued progress in this new field of liver imaging may have profound implications for large patient groups at risk for liver disease.

Signal intensity of the liver parenchyma in microbubble contrast agent in the late liver phase reflects advanced fibrosis of the liver

BACKGROUND

Microbubble of Levovist accumulates in liver parenchyma, and the phenomenon has been reported as late liver-specific parenchymal. The aim of the present study was to compare the parenchymal enhancement effect of Levovist with the degree of liver dysfunction.

PATIENTS AND METHODS

Sixty consecutive patients who consented to be treated were enrolled in this study. Pulse-inversion ultrasonography (US) in the liver parenchymal phase of enhancement with Levovist was performed in a preoperative examination. The mechanical index of pulse-inversion US was set at 1.3. The gray-scale intensity of the non-tumor area of the liver parenchyma at the level of the focal zone was measured. The hepatic fibrosis index was measured in each liver by morphometric analysis. The correlation between the gray-scale intensity of the non-tumor area of the liver parenchyma and the hepatic fibrosis index was assessed.

RESULTS

There was a significant inverse correlation between the gray scale of the liver parenchyma and the hepatic fibrosis index (r = -0.809, P < 0.01). The average signal intensity of the liver parenchyma was 144.5 in a normal liver, 133.6 in chronic hepatitis, and 102.6 in liver cirrhosis, demonstrating a significant difference between a normal and cirrhotic liver (P < 0.01).

CONCLUSIONS

The signal intensity of a microbubble disruption of the liver parenchyma in the late phase of enhancement with Levovist was considered to reflect the degree of hepatic fibrosis.

Spectral triangulation molecular contrast optical coherence tomography with indocyanine green as the contrast agent

We report a new molecular contrast optical coherence tomography (MCOCT) implementation that profiles the contrast agent distribution in a sample by measuring the agent's spectral differential absorption. The method, spectra triangulation MCOCT, can effectively suppress contributions from spectrally dependent scatterings from the sample without a priori knowledge of the scattering properties. We demonstrate molecular imaging with this new MCOCT modality by mapping the distribution of indocyanine green, a FDA-approved infrared red dye, within a stage 54 Xenopus laevis.

Survival after elective transjugular intrahepatic portosystemic shunt creation: prediction with model for end-stage liver disease score

PURPOSE

To evaluate the ability of a model of end-stage liver disease (MELD) score to predict survival in a diverse group of patients who underwent elective transjugular intrahepatic portosystemic shunt (TIPS) creation in two tertiary care institutions.

MATERIALS AND METHODS

Patients who underwent elective TIPS creation in two institutions between May 1, 1999, and June 1, 2002, were selected. Patients who underwent emergency TIPS creation were excluded. One hundred sixty-six patients met the inclusion criteria. The MELD score was computed and compared with the survival rate. Survival curves were estimated with Kaplan-Meier product limit estimates and were compared with the log-rank test. Accuracy of the model was evaluated with the c statistic.

RESULTS

The survival rate for all patients was 88.4% at 30 days, 78.1% at 3 months, and 71.8% at 6 months. Significantly lower survival rates were found in patients with MELD scores of 18 or more in comparison to those with MELD scores of 17 or less (P =.001). The c statistic for prediction of 3-month survival on the basis of the MELD score was 0.76. The early (30-day) death rate for this series was 11.4%. There was a significant difference in the 30-day mortality rate between patients with MELD scores of 17 or less and those with scores of 18 or more (P =.001). Patients who underwent TIPS creation for the management of refractory ascites had a significantly lower survival rate in comparison to that for the management of variceal bleeding (P =.001).

CONCLUSION

Results confirm that after elective TIPS creation, patients with a MELD score of 18 or more have a significantly lower 3-month survival rate than do those with a MELD score of 17 or less.

Evaluation of liver functional reserve by combining D-sorbitol clearance rate and CT measured liver volume

AIM: Our research attempted to evaluate the overall functional reserve of cirrhotic liver by combination of hepatic functional blood flow, liver volume, and Child-Pugh’s classification, and to discuss its value of clinical application.

METHODS: Ninety two patients with portal hypertension due to hepatic cirrhosis were investigated. All had a history of haematemesis and hematochezia, esophageal and gastric fundus varices, splenomegaly and hypersplenia. A 2-year follow-up was routinely performed and no one was lost. Twenty two healthy volunteers were used as control group. Blood and urine samples were collected 4 times before and after intravenous D-sorbitol infusion. The hepatic clearance (CL_H) of D-sorbitol was then calculated according to enzymatic spectrophotometric method while the total blood flow (Q_TOTAL) and intrahepatic shunt (R_INS) were detected by multicolor Doppler ultrasound, and the liver volume was measured by spiral CT. Data were estimated by t-test, variance calculation and chi-squared test. The relationships between all these parameters and different groups were investigated according to Child-Pugh classification and postoperative complications respectively.

RESULTS: Steady blood concentration was achieved 120 mins after D-sorbitol intravenous infusion, which was (0.358 ± 0.064) mmol·L^-1 in cirrhotic group and (0.189 ± 0.05) mmol·L^-1 in control group (P < 0.01). CL_H = (812.7 ± 112.4) mL·min^-1, Q_TOTAL = (1280.6 ± 131.4) mL·min^-1, and R_INS = (36.54 ± 10.65)% in cirrhotic group and CL_H = (1248.3 ± 210.5) mL·min^-1, Q_TOTAL = (1362.4 ± 126.9) mL·min^-1, and R_INS = (8.37 ± 3.32)% in control group (P < 0.01). The liver volume of cirrhotic group was 1057 ± 249 cm³, 851 ± 148 cm³ and 663 ± 77 cm³ in Child A, B and C group respectively with significant difference (P < 0.001). The average volume of cirrhotic liver in Child B, C group was significantly reduced in comparison with that in control group (P < 0.001). The patient, whose liver volume decreased by 40% with the CL_H below 600 mL·min^-1, would have a higher incidence of postoperative complications. There was no strict correspondent relationship between CL_H, liver volume and Child-Pugh’s classification.

CONCLUSION: The hepatic clearance of D-sorbitol, CT measured liver volume can be reliably used for the evaluation of hepatic functional blood flow and liver metabolic volume. Combined with the Child-Pugh’s classification, it could be very useful for further understanding the liver functional reserve, therefore help determine reasonable therapeutic plan, choose surgical procedures and operating time.