Analysis of risk factors for massive intraoperative bleeding during laparoscopic splenectomy

Background/Purpose

Laparoscopic splenectomy is occasionally converted to open surgery due to massive intraoperative bleeding. The aim of this study was to identify the risk factors for massive bleeding during laparoscopic splenectomy.

Methods

Fifty-three patients underwent laparoscopic splenectomy. The indications were hematologic disease in 25 patients, liver cirrhosis in 17 patients, and other conditions in 11 patients. Univariate analysis was conducted with Fisher's exact test, and multivariate analysis was conducted with a stepwise logistic regression model.

Results

None of the patients required open surgery. Blood loss of more than 800?ml was defined as massive intraoperative bleeding. Univariate analysis showed significant risk factors for massive bleeding to be liver cirrhosis, portal hypertension, splenomegaly, Child class, and preoperative platelet count. Independent risk factors in the multivariate analysis were portal hypertension and Child class.

Conclusions

Careful attention to intraoperative bleeding during laparoscopic splenectomy is necessary for patients with portal hypertension and/or deteriorated liver function.     

A scoring system for the assessment of the risk of mortality after partial hepatectomy in patients with chronic liver dysfunction

Background/purpose

The aim of this study is to evaluate a new scoring system, called the chronic liver dysfunction (CLD) score, for prediction of the surgical risk of partial hepatectomy in patients with chronic liver damage. Morbidity and mortality rates after gastroenterological surgery are high in patients with hepatic cirrhosis. Accordingly, it is very important to assess the surgical risk in such patients before surgery. Although the Child classification (or Child–Pugh score) has been a standard system, it did not always accurately predict patients at the risk of mortality after gastroenterological surgery, especially partial hepatectomy.

Methods

In 1985, we established a new system called the CLD score, reviewing the patients undergoing gastroenterological operations at one hospital. In the present study, we prospectively used the CLD score in 256 consecutive patients with chronic liver dysfunction who were treated surgically by partial hepatectomy, and investigated the usefulness of the CLD score concerning mortality. The results were compared with those of the Child–Pugh score (C-P score).

Results

After major hepatectomy, all the patients with CLD score exceeding 1.5 died of hepatic failure. After minor hepatectomy, all the patients with CLD score exceeding 2.5 died of hepatic failure. On the other hand, C-P score did not predict the outcome in these patients.

Conclusions

Compared with the C-P score, which was considered the gold standard scoring system for assessing surgical risk for patients with chronic liver dysfunction, our CLD score provides a more reliable assessment of the risk of partial hepatectomy.     

A simple, noninvasively determined index predicting hepatic failure following liver resection for hepatocellular carcinoma

Background

A novel index, the serum aspartate aminotransferase activity/platelet count ratio index (APRI), has been identified as a biochemical surrogate for histological fibrogenesis and fibrosis in cirrhosis. We evaluated the ability of preoperative APRI to predict hepatic failure following liver resection for hepatocellular carcinoma.

Methods

Potential preoperative risk factors for postoperative hepatic failure (hepatic coma with hyperbilirubinemia, four patients; intractable pleural effusion or ascites, 30 patients; and variceal bleeding, one patient) as well as APRI were evaluated in 366 patients undergoing liver resection for hepatocellular carcinoma. Prognostic significance was determined by univariate and multivariate analyses.

Results

Hepatic failure developed postoperatively in 30 patients, causing death in four. APRI correlated with histological intensity of hepatitis activity and degree of hepatic fibrosis, and was significantly higher in patients who developed postoperative hepatic failure than in others without failure. Risk of postoperative hepatic failure increased as the serum albumin concentration and platelet count decreased and as indocyanine green retention rate at 15 min, aspartate and alanine aminotransferase activities, and APRI increased. Only APRI was an independent preoperative factor on multivariate analysis. Of the four patients who died of postoperative hepatic failure, three had an APRI of at least 10.

Conclusions

Preoperative APRI independently predicted hepatic failure following liver resection for hepatocellular carcinoma. Patients with an APRI of 10 or more have a high risk of postoperative hepatic failure.     

Usefulness of intraoperative fluorescence imaging to evaluate local anatomy in hepatobiliary surgery

Background/Purpose

One of the major complications encountered in hepatobiliary surgery is the incidence of bile duct and blood vessel injuries. It is sometimes difficult during surgery to evaluate the local anatomy corresponding to hepatic arteries and bile ducts. We investigated the potential utility of an infrared camera system as a tool for evaluating local anatomy during hepatobiliary surgery.

Methods

An infrared camera system was used to detect indocyanine green fluorescence in vitro. We also employed this system for the intraoperative fluorescence imaging of the arteries and biliary system in a pig. Further, we evaluated blood flow in the hepatic artery, portal vein, and liver parenchyma during a human liver transplant and we investigated local anatomy in patients undergoing cholecystectomy.

Results

Fluorescence confirmed that indocyanine green was distributed in serum and bile. In the pig study, we confirmed the fluorescence of the biliary system for more than 1 h. In the liver transplant recipient, blood flow in the hepatic artery and portal vein was confirmed around the anastomosis. In most of the patients undergoing cholecystectomy, fluorescence was observed in the gallbladder, cystic and common bile ducts, and hepatic and cystic arteries.

Conclusions

Intraoperative fluorescence imaging in hepatobiliary surgery facilitates better understanding of the anatomy of arteries, the portal vein, and bile ducts.     

Reducing the incidence of post-hepatectomy hepatic complications by preoperatively applying parameters predictive of liver function

Background/purpose

To prevent or reduce hepatic complications after hepatectomy, it is important to employ preoperative predictive parameters and to determine the indications for hepatectomy. In the present study, we evaluated risk parameters in patients who underwent hepatectomy between 1994 and 2003, and selected three parameters to modify the surgical indications. Using these indications before surgery in patients who underwent hepatectomy between 2004 and 2008, we compared the prevalences of postoperative complications in the the two groups of patients.

Methods

We examined 250 consecutive patients who underwent hepatectomy for liver disease [149 in 1994–2003 (termed the early period) and 101 in 2004 to 2008 (termed the later period)].

Results

In the early period, uncontrolled ascites was observed in 55 patients and hepatic failure was observed in 15 of the 149 patients. Multivariate analysis identified volume of the resected liver (≥50%), intraoperative blood loss (≥1500 ml), prothrombin activity (<70%), hyaluronic acid level (≥200 ng/ml), and LHL15 (hepatic uptake ratio of technetium-99m galactosyl human serum albumin (^99mTc-GSA) (<0.85) as risk factors; the latter three parameters were evaluated as predictors of outcome. From 2004, we used these three parameters, in addition to the indocyanine green retention rate at 15 min (ICGR15), as criteria for indications for hepatectomy. Despite the lower prevalence of normal liver in the later period, comparisons showed decreases in the rates of uncontrolled ascites (23 vs. 37%, P = 0.03), hepatic failure (4 vs. 10%, P = 0.12), and hepatic complications (25 vs. 44%, P = 0.003) in patients in the later period compared with these rates in the previous period.

Conclusions

The use of prothrombin activity, and levels of hyaluronic acid and LHL15, as parameters of functional liver reserve in the selection of candidates for surgery reduced the incidence of hepatic complications after hepatectomy.     

Morphogenesis of an anomalous ligamentum venosum terminating in the superior left hepatic vein in a human liver

Background/Purpose

We aimed to clarify the morphogenesis of an anomalous ligamentum venosum terminating in the trunk of the superior left hepatic vein, because the ligamentum venosum ordinarily terminates into the root of the left hepatic vein or directly into the inferior vena cava.

Methods

We examined an anomalous ligamentum venosum found in the cadaveric liver of an 84-year-old Japanese woman.

Results

The ligamentum venosum in this liver was not found in the usual course, the fissure for the ligamentum venosum. It lay on the posterior surface of the liver, connecting the left branch of the portal vein and the trunk of a small left hepatic vein. The small left hepatic vein draining the cranio-dorsal part of the lateral segment of the liver was revealed to be a superior left hepatic vein. This type of anomaly was found only in this 1 liver, among 125 cadaveric livers that were dissected.

Conclusions

Taking previous reports into consideration, the morphogenesis of the anomalous ligamentum venosum in the present case may be explained as being due to the persistence of the right half of the subdiaphragmatic anastomosis, which receives the blood from the ductus venosus in the embryonal period.     

Patterns of chemotherapy-induced hepatic injury and their implications for patients undergoing liver resection for colorectal liver metastases

Background and aims

Neoadjuvant chemotherapy is increasingly being used to enlarge the cohort of patients who can be offered hepatic resection for malignancy. However, the impact of these agents on the liver parenchyma itself, and their effects on clinical outcomes following hepatic resection remain unclear. This review identifies patterns of regimen-specific chemotherapy-induced hepatic injury and assesses their impact on outcomes following hepatic resection for colorectal liver metastases (CLM).

Methods

An electronic search was performed using the MEDLINE (US Library of Congress) database from 1966 to May 2007 to identify relevant articles related to chemotherapy-induced hepatic injury and subsequent outcome following hepatic resection.

Results

The use of the combination of 5-flourouracil and leucovorin is linked to the development of hepatic steatosis, and translates into increased postoperative infection rates. A form of non-alcoholic steatohepatitis (NASH) related to chemotherapy and otherwise known as chemotherapy-associated steatohepatitis (CASH) is closely linked to irinotecan-based therapy and is associated with inferior outcomes following hepatic surgery mainly due to hepatic insufficiency and poor regeneration. Data on sinusoidal obstruction syndrome (SOS) following treatment with oxaliplatin are less convincing, but there appears to be an increased risk for intra-operative bleeding and decreased hepatic reserve associated with the presence of SOS. Intra-arterial floxuridine therapy damages the extrahepatic biliary tree in addition to causing parenchymal liver damage, and has been shown to be associated with increased morbidity after hepatic resection.

Conclusion

Agent-specific patterns of damage are now being recognized with increasing use of neoadjuvant chemotherapy prior to surgery. The potential benefits and risks of these should be considered on an individual patient basis prior to hepatic resection.     

Hepatic Arteriovenous Fistulae: Role of Interventional Radiology

Introduction

Hepatic arterial venous fistulae are abnormal communications between the hepatic artery and portal or hepatic vein and commonly occur either secondary to iatrogenic causes like liver biopsy, transhepatic biliary drainage, transhepatic cholangiogram and surgery, or following mechanical insult like blunt or penetrating trauma. Congenital fistulae are rare. Treatment is warranted as an emergency management or in the development of portal hypertension/heart failure in chronic cases. Both surgical and endovascular occlusion of the fistula can be attempted with the latter carrying low intra and post-procedure morbidity. Endovascular treatment has thus currently emerged as a minimally invasive reliable treatment option in such individuals.

Methods and Results

We describe a short series consisting of four cases of acquired hepatic arterioportal/venous fistulae, which were referred to interventional radiology for endovascular management over the last 2 years. Three patients had arterio-portal communication and one patient had communication between the hepatic artery and middle hepatic vein. Successful embolization through the transarterial route was achieved in all four patients. A brief discussion of these cases is presented along with a relevant review of literature.

Conclusions

Endovascular techniques currently form less invasive and first line treatment options in arterioportal/venous fistulae, surgery being reserved only for unsuccessful embolizations/complex fistulae.     

Imaging Appearance in Acute Liver Failure: Correlation with Clinical and Pathology Findings

Background and Aim

Acute liver failure (ALF) is characterized by sudden liver injury without underlying chronic liver disease. Excluding underlying cirrhosis in these patients is often difficult and liver biopsy may be impractical. We review the imaging appearance of acute hepatic failure in patients who underwent transplant and correlate these findings with clinical, laboratory and pathology parameters.

Methods

This is a retrospective review of 47 patients without known chronic liver disease who presented to three institutions between 2002 and 2010 with ALF, 46 of which underwent subsequent orthotopic liver transplantation. Pre-transplant ultrasound, computed tomography and magnetic resonance imaging scans were reviewed for parenchymal homogeneity, surface nodularity and evidence of portal hypertension. Explant histopathology, laboratory values and time intervals between symptom onset to initial imaging and transplant were correlated with imaging findings.

Results

The majority of patients with ALF had abnormal radiographic findings. Ascites was seen in 65 % of patients. Splenomegaly, collateral vessel formation and hepatofugal flow in the portal vein were present in 28, 15 and 9 % of patients, respectively. Nodular liver surface was noted in 23 % of patients, more commonly in patients who had been ill for more than 7 days. Liver surface nodularity correlated with massive hepatic necrosis on histology and wrinkled capsule on visual inspection of explanted liver specimen.

Conclusion

Imaging findings in ALF was variable and can resemble cirrhosis. Assessment for underlying cirrhosis in the setting of liver failure should not be based on imaging findings.     

Clinical results of N-acetylcysteine after major hepatic surgery: a review

Background/Purpose

Ischemia/reperfusion injury is thought to play an important role in postoperative liver dysfunction and morbidity following major liver surgery. N-acetylcysteine may be protective by serving as a precursor to glutathione and replenishing intracellular stores, in addition to other mechanisms. The purpose of this review is to summarize the clinical evidence that N-acetylcysteine may reduce liver dysfunction and the postoperative complications following major liver surgery.

Methods

A PubMed (MEDLINE) search was performed using the search terms “N-acetylcysteine”, “Mucomyst”, “liver”, and “surgery” to identify all relevant articles published in English prior to February 2007.

Results

Seventy-three articles were identified, and of these, there were seven studies that involved human patients undergoing orthotopic liver transplantation (six randomized controlled trials and one retrospective study).

Conclusions

The evidence that routine use of N-acetylcysteine reduces ischemia/reperfusion injury and prevents complications after major liver surgery is not conclusive. The available studies may have been limited by small sample sizes, and heterogeneous outcome measures prevent conclusions being made across studies and prevent pooling of the data. Further study with more relevant clinical endpoints and larger sample sizes is warranted.     

Outcome of patients following hepatic resection for metastatic cutaneous and ocular melanoma

Background/purpose

The aim of this study was to analyze the outcome of patients undergoing hepatic resection for melanoma liver metastases.

Methods

Patients undergoing liver resection for melanoma metastases at the Hospital Vall d??Hebron and Hospital Clinic, Barcelona, were reviewed. Selection criteria were: good performance status, feasibly complete and safe resection, and absence of visceral extrahepatic metastases.

Results

Between 1994 and 2007, 14 liver resections were performed for melanoma liver metastases. The primary tumor was cutaneous in 8 patients and ocular in 6. Two patients underwent urgent liver surgery due to tumor bleeding. In these patients, complete melanoma staging was not performed and extrahepatic metastases were found during surgery or during the postoperative course. Six of 13 patients (46.2%) developed liver recurrence during follow-up. One- and 3-year actuarial patient survivals were 77 and 49%, respectively. Excluding the patients who underwent urgent liver surgery, the 1- and 3-year actuarial patient survivals in those with primary ocular and cutaneous melanoma were 83 and 56% and 80 and 60%, respectively.

Conclusions

Liver resection may be considered as part of oncosurgical treatment in patients with melanoma liver metastases, since prolonged survival was observed, albeit with a high recurrence rate. Nevertheless, it should be taken into account that our study included only a small number of patients.     

Laparoscopic left lateral hepatic lobectomy: a safer and faster technique

Background/Purpose

Laparoscopy for liver resection is highly specialized field because laparoscopic liver surgery presents severe technical difficulties, such as control of bleeding and risk of gas embolism. At present, a limited number of laparoscopic anatomical left lobectomies have been reported in the literature, but we believe that the use of stapling devices has made this technique safer and faster.

Methods

From January 2000 to May 2005, eight patients (five men, three women; mean age, 60.5 years) underwent laparoscopic anatomical left lobectomy at our department. Seven patients presented with hepatocellular carcinoma and cirrhosis, while one patient had a large symptomatic angioma. The average size of the lesions was 4.18?cm (range, 3.6–7.1?cm); all the lesions were localized in the anatomical left lobe (segments II–III). Transection of the liver parenchyma, together with sectioning of the vascular pedicle for segment II and III and of the left hepatic vein, was obtained by the use of stapling devices.

Results

The mean operative time was 142?min (range, 120–180?min). There were no intraoperative or postoperative complications, and blood transfusions were not required. The mean postoperative hospital stay was 5.75 days.

Conclusions

The key points of the technique are: late mobilization of the liver; no transection of the round ligament; no surrounding or taping of the portal pedicles or of the left hepatic vein; and the use of three consecutive linear staplers, turned to the left for transecting the liver parenchyma and vascular pedicle together. This technique, in our opinion, should be considered a new good option for patients with isolated lesions of the left lateral segments, but it must be performed by surgeons trained in both liver and advanced laparoscopic surgery.     

Regional Hepatic Regeneration After Liver Resection Correlates Well with Preceding Changes in the Regional Portal Circulation in Humans

Background and Aims

While portal hemodynamics largely affects the liver regeneration after partial hepatectomy, whether the remnant liver homogeneously regenerates is unclear, especially in humans. We hypothesized that change in flow distribution varies in each remnant portal branch after liver resection in humans and the liver consequently regenerates heterogeneously.

Methods

Twenty-two patients who underwent anatomical hepatic resection preserving intact drainage veins were analyzed. Based on perioperative contrast-enhanced computed tomography, the regional hepatic regeneration in each segment was analyzed using a region growing software. The perioperative change in the distribution of blood flow in each portal branch was assessed using the computational flow dynamics technique. The correlation between the change in the portal flow distribution and the later regional hepatic regeneration was investigated.

Results

The distribution of portal blood flow in each remnant branch largely changed at 2 weeks (71–389 %). Each remnant segment also heterogeneously regenerated at 3 months (85–204 %). Meanwhile, a good correlation between the regional regeneration rate at 3 months and the relative change in the flow distribution in each circulating portal branch at 2 weeks was detected in each patient (r = 0.74–0.99).

Conclusions

After partial hepatectomy, the change in blood flow varies in each remnant portal branch and the liver heterogeneously regenerates in humans. The good correlation between the earlier change in the portal flow distribution and the later regional hepatic regeneration strongly suggests that the portal venous flow most likely regulates the non-uniform liver regeneration after hepatic resection in humans.     

Intraoperative fluorescent imaging using indocyanine green for liver mapping and cholangiography

Background

Preoperative imaging is widely used and extremely helpful in hepatobiliary surgery. However, transfer of preoperative data to a intraoperative situation is very difficult. Surgeons need intraoperative anatomical information using imaging data for safe and precise operation in the field of hepatobiliary surgery. We have developed a new system for mapping liver segments and cholangiograms using intraoperative indocyanine green (ICG) fluorescence under infrared light observation.

Method

The imaging technique for mapping liver segments and cholangiogram based on ICG fluorescence used an infrared-based navigation system. Eighty one patients with liver tumors underwent hepatectomy from 2006, January to 2009, March. In liver surgery, 1 ml of ICG was injected via the portal vein under observation by the fluorescent imaging system. Fourteen patients were underwent laparoscopic cholecystectomy for chronic cholecystitis with gallstones. In laparoscopic cholecystectomy, 5 ml of ICG was administered intravenously just before operation and the bile duct was observed using the infrared-based navigation system.

Result

This new technique successfully identified stained subsegments and segments of the liver in 73 of 81 patients (90.1%). Moreover, clear mapping of liver segments was obtained even against a background of liver cirrhosis. Fluorescent cholangiography clearly showed the common bile duct and cystic duct in 10 of 14 patients (71.4%). No adverse reactions to the ICG were encountered.

Conclusion

Application of this technique allows intraoperative identification of anatomical landmark in hepatobiliary surgery.     

Portal blood flow via the peribiliary vascular plexus demonstrated by contrast-enhanced ultrasonography with Sonazoid

Purpose

We report two cases in which portal blood flow via the peribiliary vascular plexus (PBP) was clearly demonstrated using contrast-enhanced intra-operative ultrasonography (CE-IOUS).

Methods

Two patients who underwent hemihepatectomies were investigated using CE-IOUS. Before injection of the contrast medium, both the hepatic arterial and portal venous flows of the hemiliver to be resected were interrupted by ligating those corresponding vessels at the hepatic hilum. Subsequently, the perfluorobutane microbubbles were injected intravenously.

Results

In the early vascular phase, a remarkable intermittent flow was visualized in the lumen of the portal branches whose inflows were interrupted. The flow of the portal vein then disappeared as a result of ligating the hepatic duct concomitantly with the surrounding connective tissue. We considered that the portal venous flow appearing under the condition of total disruption of original inflow was supplied from the hepatic artery through the PBP.

Conclusions

This is the first report of blood flow via the PBP in human liver visualized by dynamic image study.     

Intraoperative assessment of reconstructed vessels in living-donor liver transplantation, using a novel fluorescence imaging technique

Background/Purpose

In living-donor liver transplantation (LDLT), hepatic arterial thrombosis and portal venous thrombosis are critical problems that can result in graft loss. Only intraoperative Doppler ultrasound (IDUS) is able to evaluate blood flow in the reconstructed vessels. The aim of this study was to evaluate the utility of a newly developed fluorescence imaging technique using indocyanine green (ICG) for visualizing reconstructed vessels.

Methods

In three patients who had undergone LDLT, IDUS was performed after reconstruction of the portal vein and hepatic artery. Fluorescence images were then recorded, using a SPY system (Novadeq Technologies), which employs ICG as a fluorescent imaging medium activated by light. The ICG (3.75?mg) was injected intravenously, then, 10?s later, the images were recorded for 30?s (first photographic recording). Two minutes later, the same procedure was repeated (second photographic recording), and 40?min later, images were obtained without injection of ICG (third photographic recording).

Results

After portal venous reconstruction, IDUS demonstrated a nonphasic and continuous waveform, with a mean velocity of 52.1?cm/s and a mean portal blood flow volume of 69.5?ml/s per kg. After hepatic arterial reconstruction, a pulsatile waveform with a mean peak systolic velocity of 52.4?cm/s and a mean resistance index of 0.76 was obtained. The first photographic recording clearly visualized the blood flow in the reconstructed hepatic artery, without kinking or stenosis, in all three patients. The second photographic recording visualized the flow in the portal vein without stenosis, kinking, or stagnation. The third photographic recording demonstrated the excretion of ICG into bile, thus confirming bile production by the grafts.

Conclusions

Fluorescence imaging can clearly visualize the reconstructed hepatic artery and portal vein and demonstrate the production of bile by a transplanted liver graft. A combination of IDUS and the new system can guarantee the patency of the reconstructed vessels.     

Impact of hepatic clearance of endotoxin using endotoxin activity assay

Background

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

Methods

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

Results

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

Conclusions

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

Risk factors contributing to hepatic artery thrombosis following living-donor liver transplantation

Background/Purpose

This study was carried out to investigate the risk factors contributing to hepatic artery thrombosis in living-donor liver transplantation.

Methods

Two hundred and twenty-two recipients (113 adults and 109 children) of living-donor liver transplantation were the subjects of this study. The diagnosis of hepatic artery thrombosis was made by color-Doppler ultrasonography and/or hepatic angiography. Parameters for this study were: (1) donor sex, age, and body weight; (2) recipient sex, age, body weight, liver disease, preoperative prothrombin time, and type of arterial reconstruction; and (3) previous liver transplantation.

Results

Hepatic artery thrombosis occurred in 12 patients (5.4%) at 3 to 15 days posttransplant. Recipient female sex and metabolic disorder as the original disease were found to be significantly associated with hepatic artery thrombosis. The 5-year patient survival rate in recipients with hepatic artery thrombosis (58.3%) was significantly lower than that in recipients without this complication (84.4%).

Conclusions

Female sex and metabolic disease may be factors contributing to hepatic artery thrombosis after living-donor liver transplantation. More intensive anticoagulation therapy for this patient population might decrease the incidence of hepatic artery thrombosis and, thus, posttransplant recipient mortality.     

Hepatic effects of influxed endothelin-1 from portal vein: in situ portal vein infusion model using dogs

Background/Purpose

Endothelin-1 is a potent vasoconstrictor formed by vascular endothelium. This study was designed to investigate the hepatic effect of endothelin-1 produced by portal vascular endothelium.

Methods

Portal venous pressure, portal venous flow, hepatic arterial flow, tissue blood flow, and tissue oxygen pressure were measured during portal vein endothelin-1 infusion in dogs at rates of 1.0 to 5.0?ng/kg per minute. Sinusoidal width during maximal infusion was determined morphometrically. Serum concentrations of mitochondrial glutamic oxaloacetic transaminase and endothelin-1 in portal and hepatic venous blood were also measured.

Results

Intraportal endothelin-1 infusion dose-dependently increased portal venous pressure and reduced portal venous and hepatic arterial blood flow. Tissue blood flow and oxygen pressure also decreased. Endothelin-1 also significantly increased serum mitochondrial glutamic oxaloacetic transaminase and constricted hepatic sinusoids. These changes reversed after completion of infusion.

Conclusions

Intraportal endothelin-1 caused circulatory and histological changes in hepatic sinusoids that may suggest the role of endothelin-1 formed by portal venous bed epithelium.