CT and MRI in detection of intrahepatic portosystemic shunts in patients with liver cirrhosis

OBJECTIVE: Our goal was to determine the prevalence and anatomic location of intrahepatic portosystemic shunts (IPSs) in patients with hepatic cirrhosis as shown by CT and MRI. MATERIALS AND METHODS: We retrospectively reviewed CT and MR scans of 33 cirrhotic patients who had IPSs. In addition, two series of 100 consecutive CT or MR were reviewed to determine the prevalence of IPSs and the percentage of intrahepatic and extrahepatic paraumbilical veins. RESULTS: Intrahepatic portosystemic shunts were divided into three groups according to the intrahepatic course: paraumbilical shunt between the left portal vein and the paraumbilical vein anterior to the liver (n = 29); inferior vena caval shunt between the posterior branch of the right portal vein and the inferior vena cava (n = 2); and miscellaneous (n = 2). Shunts of the paraumbilical type ran through the medial (n = 23), lateral (n = 3), or both medial and lateral (n = 3) segments of the left lobe of the liver. Twenty-five patients had one shunt, and four had more than one. Six cases were also associated with extrahepatic paraumbilical veins. CONCLUSION: Intrahepatic portosystemic shunts, especially the paraumbilical type, were not infrequently visualized in patients with hepatic cirrhosis.     

Multicenter trial on prognostic value of inducible ischemia, assessed by dobutamine stress echocardiography and exercise electrocardiography test, in patients with uncomplicated myocardial infarction, treated with thrombolytic therapy

Reduction of the splenic volume by partial resection and collateral development after transposition are of potential value in the elective treatment of esophageal varices, hypersplenism and ascites. A study was performed on young Wistar rats. A simple animal model of extrahepatic portal hypertension was used, narrowing the portal vein to an outer diameter of one millimeter (PVS). One day, three weeks and seven weeks after this operation the portal venous pressure was elevated as compared with the sham-operated controls. The portal hypertension was statistically significant at week three (1.31 +/- 0.04 vs. 0.72 +/- 0.18 kPa, p = 0.01). Portocaval pressure gradient after partial resection of the spleen (SR) and intramuscular transposition (IMTrans) was compared with the pressure gradient after graded portal vein stenosis. Three weeks after intramuscular transposition portocaval pressure gradient was reduced (1.46 +/- 0.38 vs. 1.74 +/- 0.13 kPa, n.s.). This data supports the hypothesis that the portal venous high-pressure compartment and the systemic venous low-pressure compartment are maintained after development of natural shunts to the systemic circulation. In the following experiment different types of splenic transposition were tested and compared to each other and a normal control group or to rats with protal vein stenosis (PVS), respectively. After PVS, the animals were reoperated, an SR was performed and the wound surface of the spleen was transposed into the left abdominal wall subcutaneously (SCTrans) or intramuscularly (IMTrans) or to the left liver lobe (splenohepatoplasty, SHP), respectively. After three weeks the animals underwent measurements of organ weights, collections of blood samples and the spleen was investigated histologically. Blood cell counts were nearly normal but total serum protein, albumin and the colloid osmotic pressure were slightly diminished or significantly reduced (COP in the groups PVS + SR + IMTrans or SCTrans, p < 0.05) compared to the controls. Differences to the group with portal vein stenosis (PVS) were not significant. Serum protein electrophoresis after splenic transposition revealed an unobtrusive distribution pattern. Animals after SHP had the best increase in weight and high protein levels, but splenohepatic collateral development seemed sparse. Differences of plasma ammonium levels were statistically not significant, but some animals had elevated levels after transposition. Morphometry of routine-stained spleen specimens showed an intact immunoarchitecture of the transposed spleens.     

Creation of transjugular intrahepatic portosystemic shunts with the wallstent endoprosthesis: results in 100 patients

One hundred patients underwent transjugular intrahepatic portosystemic shunt (TIPS) creation for variceal bleeding (n = 94), intractable ascites (n = 3), hepatorenal syndrome (n = 2), and preoperative portal decompression (n = 1). Shunts were completed in 96 patients. Portal vein pressure was reduced from 34.5 mm Hg +/- 7.6 (standard deviation) to 24.5 mm Hg +/- 6.2; the residual portal vein-hepatic vein gradient was 10.4 mm Hg +/- 0.9. Acute variceal bleeding was controlled in 29 of 30 patients. Of the 96 patients who underwent successful TIPS creation, 26 have died and 22 have undergone liver transplantation; the remaining 48 patients have survived an average of 7.6 months. Variceal bleeding recurred in 10 patients. Fifteen patients developed shunt stenosis (n = 6) or occlusion (n = 9). Patency was reestablished in eight of the nine occluded shunts. Seventeen patients developed new or worsened encephalopathy. The authors conclude that TIPS creation is an effective and reliable means of lowering portal pressure and controlling variceal bleeding, particularly in patients with acute variceal bleeding unresponsive to sclerotherapy and patients with chronic variceal bleeding before liver transplantation.     

Study of FHIT transcripts in normal and malignant breast tissue

The purpose of this study was to determine the utility of intraoperative Doppler ultrasound for the diagnosis and reduction of the vascular complications in liver transplantation. This study included 19 pediatric and 5 adult patients. In the pediatric group, 12 patients received living related liver transplantation (LRLT), two splitting liver transplantation (SLT), three reduced-size liver transplantation (RLT) and two full-size pediatric liver transplants (FPLT). The hemodynamics and waveform of the hepatic vein, portal vein and hepatic artery were evaluated by intraoperative Doppler ultrasound (US) after reperfusion of the graft. Unsatisfactory hemodynamics was identified in nine cases, including decrease hepatic venous flow (6-9 cm/s) with non-pulsative flat waveform (adults, n = 2 and LRLT, n = 2); portal vein thrombosis (LRLT, n = 1); decrease portal flow (8 mL/min/kg) (LRLT, n = 1); occlusion of the portal vein (SLT, n = 1); poor arterial flow with dampened artery waveform (FPLT, n = 2). These abnormalities were all successfully re-reconstructed by surgical procedures and achieved a graft survival rate of 100%. Two late vascular complications including hepatic venous thrombosis and recurrent portal vein stenosis with splenorenal shunt were discovered 1 month later. They were treated effectively by surgical thrombolectomy and percutaneous balloon dilatation and metallic coils embolization respectively. Three patients died of non-vascular complications and all patients who underwent LRLT survived with a resultant 87.5% overall survival rate. In conclusion, intraoperative Doppler US is efficient in detecting abnormal hepatic hemodynamics, which permits early intervention and hence a better prognosis for the patients. Re-reconstructive procedures were monitored closely under Doppler US guidance until proper flow and wave-form were established. This reduces post-transplant vascular complications and thereby eliminates the likelihood of a lethal complication that might call for re-transplantation.     

Food, obesity and non-insulin-dependent diabetes: are there molecular links?

BACKGROUND & AIMS: The effects of transjugular intrahepatic portosystemic shunt (TIPS) on portal hemodynamics, esophageal and gastric varices, and hepatic function have not been fully defined. The aim of this study was to define prospectively the effects of TIPS on portal pressures and flow, variceal resolution, and hepatic function. METHODS: Pressure and flow measurements were made by angiography and Doppler sonography, respectively. Varices were assessed by endoscopy and angiography. Liver functions were evaluated by a battery of tests. RESULTS: In 100 consecutive subjects, mean portosystemic gradient decreased from 24 to 11 mm Hg (means) (P < 0.001) after TIPS. Recurrent portal hypertension caused by stent thrombosis (n = 5), stent retraction (n = 2), and stent stenosis (n = 51) occurred at 6 months but, by year 5, was not present in survivors (n = 0 of 8). Fundic gastric varices failed to resolve in 6 of 12 cases. Systemic venous pressures of >15 mm Hg, stent dysfunction, and continued alcoholism were risk factors for recurrent hemorrhage. Angiography was superior to endoscopy, which was superior to Doppler sonography for detection of recurrent portal hypertension. Progressive liver failure occurred in 8 patients. CONCLUSIONS: Recurrent portal hypertension caused by stent stenosis occurs commonly in the first 2 years after TIPS. Fundic gastric varices often fail to disappear after TIPS. The effects of TIPS on liver function are unpredictable.     

Portal vein ligation selectively lowers hepatic cytochrome P450 levels in rats

In rats, surgical creation of a portacaval shunt leads to hepatic atrophy and lowered levels of cytochrome P450, the key component of liver enzymes involved with drug metabolism. These effects are largely attributable to diversion of portal blood away from the liver and not to decreased hepatic blood flow. The present study has established a simpler model of portal blood diversion in order to examine the role of portal blood constituents in the regulation of hepatic cytochrome P450. Portal vein ligation was performed on male Wistar rats in which portasystemic anastomoses had been produced by subcutaneous transposition of the spleen. Portal vein ligation resulted in portal hypertension, as evidenced by splenomegaly, and in hepatic atrophy. In liver of rats with portal vein ligation, microsomal cytochrome P450 levels were significantly less than in sham-operated control rats, but cytochrome b5, NADPH-cytochrome c reductase, and glucose-6-phosphatase were unaltered. The activities of four mixed function oxidases also were reduced significantly in the liver of rats with portal vein ligation, the changes being greatest for ethylmorphine N-demethylase, a prototype substrate for the phenobarbital-inducible isoenzyme of cytochrome P450. In contrast, the activity of microsomal heme oxygenase, the rate-limiting step in catabolism of heme to bilirubin, was enhanced after portal vein ligation. Experiments in pair-fed rats showed that the changes observed in liver from rats with portal vein ligation could not be attributed to caloric deprivation. Administration of phenobarbital increased liver mass, cytochrome P450 levels, and mixed function oxidase activities both in rats with portal vein ligation and in controls, indicating that the liver of the ligated rats retained considerable protein synthetic capacity. It appears that hepatic atrophy and lowering of cytochrome P450 levels that follow portal vein ligation are consequences of altered exposure of the liver to factors normally present in portal blood, and that the same alterations may also enhance heme oxygenase activity.     

Significance of radioisotope bone marrow uptake on 99m technetium sulphocolloid scan in portal hypertension

A prospective study of 101 consecutive patients of portal hypertension was carried out to study the possible relationships between bone marrow activity on 99m technetium labelled sulphocolloid scan and severity of liver disease, etiology of portal hypertension and cirrhosis, as well as presence and extent of collateral circulation, including esophageal varices. The patients were divided into 4 etiological groups: alcoholic cirrhosis (ALD), (38) non-alcoholic cirrhosis (NALD) (35) non-cirrhotic portal fibrosis (NCPF) (14) and extrahepatic portal vein obstruction (EHPVO) (14). Patients of cirrhosis were categorised according to modified Child-Pugh's classification. Esophageal varices were graded endoscopically as (1) no varix (2) small varices (< 5mm) (3) large varices (> 5mm). All patients underwent radionuclide imaging using 99m Technetium labelled sulphocolloid and bone marrow activity was studied. Evaluation of portasystemic collaterals was done ultrasonically. We found that 16.6%, 44.6% and 72.72% patients with Child A, B and C cirrhosis respectively, had increased marrow activity (p < 0.05). There was no significant difference between marrow activity of patients with ALD (52.6%) and NALD (40%). None of the non-cirrhotic patients demonstrated bone marrow uptake of radioisotope. There was no significant difference between bone marrow uptake presence of lienorenal collaterals and presence or size of esophageal varices. We thus conclude the bone marrow activity on radioisotope scanning depends only on the severity of liver disease and does not vary a according to the etiology of cirrhosis, or presence and extent of portasystemic collaterals, including esophageal varices.     

Therapy of venous stenosis using wall stents

OBJECTIVE: To evaluate the patency of Wallstents implanted for the treatment of venous stenoses in patients with benign or malignant disease. PATIENTS AND METHODS: 22 Wallstents (20 central venous; two peripheral) were implanted during a period of two years in 12 patients (nine men, three women; mean age 57.8 [26-76] years) with malignant venous stenoses (n = 9) or stenosed dialysis shunts (n = 3). Stent diameter ranged from 8-16 mm, length from 32-91 mm. Introduction of the stents were by percutaneous transfemoral catheterisation, in six patients with simultaneous wire placement from a cubital to the femoral vein. The superior vena cava was the involved vessel in six patients (in two each also the subclavian or brachiocephalic veins), in three only the subclavian vein, twice only the inferior vena cava and once the cephalic vein. RESULTS: The patency of the stents was checked after 4.7 +/- 3.6 (1-14) months, in seven patients clinically, by digital subtraction phlebography in three, by computed tomography in two. In nine patients there was no evidence of obstruction to flow or flow was normal. Stent occlusion had occurred in three patients, 4, 9 and 14 months after placement. There were no complications. Five patients died after a mean period of 4.8 +/- 3.6 (1-6.5) months from the underlying disease, without symptoms of obstruction to flow. CONCLUSION: Stent placement should be considered early, as it is a well-tolerated and effective palliative procedure for central venous stenoses associated with malignant disease or stenosis of dialysis shunts.     

Doppler US of helical flow in the portal vein

In helical portal venous blood flow, the usual laminar flow in the portal vein is replaced by a spiral. This changes the color Doppler ultrasound (US) appearance to one of alternating or parallel red and blue bands. Duplex US may appear to show hepatopetal, hepatofugal, or simultaneous bidirectional flow depending on placement of the cursor within the helix. Helical portal venous flow is unusual in normal individuals (2.2% of 135 patients). Its presence should prompt further scrutiny for signs of liver disease, particularly portosystemic shunts, as in 20% of 41 patients who subsequently underwent liver transplantation. It is a normal finding immediately after liver transplantation (43% of 35 patients) and transjugular intrahepatic portosystemic shunt (TIPS) creation (28% of 36 patients). In both liver transplant and TIPS recipients, helical flow is usually transient. Its persistence long after transplantation in association with a prolonged increase in portal venous velocity is a useful sign of portal vein stenosis. Helical flow may also occur in cases of neoplastic invasion or displacement of the portal vein.     

The changing spectrum of treatment for variceal bleeding

OBJECTIVE: The objective of this study was to assess the impact of endoscopic therapy, liver transplantation, and transjugular intrahepatic portosystemic shunt (TIPS) on patient selection and outcome of surgical treatment for this complication of portal hypertension, as reflected in a single surgeon's 18-year experience with operations for variceal hemorrhage. SUMMARY BACKGROUND DATA: Definitive treatment of patients who bleed from portal hypertension has been progressively altered during the past 2 decades during which endoscopic therapy, liver transplantation, and TIPS have successively become available as alternative treatment options to operative portosystemic shunts and devascularization procedures. METHODS: Two hundred sixty-three consecutive patients who were surgically treated for portal hypertensive bleeding between 1978 and 1996 were reviewed retrospectively. Four Eras separated by the dates when endoscopic therapy (January 1981), liver transplantation (July 1985), and TIPS (January 1993) became available in our institution were analyzed. Throughout all four Eras, a selective operative approach, using the distal splenorenal shunt (DSRS), nonselective shunts, and esophagogastric devascularization, was taken. The most common indications for nonselective shunts and esophagogastric devascularization were medically intractable ascites and splanchnic venous thrombosis, respectively. Most other patients received a DSRS. RESULTS: The risk status (Child's class) of patients undergoing surgery progressively improved (p = 0.001) throughout the 4 Eras, whereas the need for emergency surgery declined (p = 0.002). The percentage of nonselective shunts performed decreased because better options to manage acute bleeding episodes (sclerotherapy, TIPS) and advanced liver disease complicated by ascites (liver transplantation, TIPS) became available (p = 0.009). In all Eras, the operative mortality rate was directly related to Child's class (A, 2.7%; B, 7.5%; and C, 26.1 %) (p = 0.001). As more good-risk patients underwent operations for variceal bleeding, the incidence of postoperative encephalopathy decreased (p = 0.015), and long-term survival improved (p = 0.012), especially since liver transplantation became available to salvage patients who developed hepatic failure after a prior surgical procedure. There were no differences between Eras with respect to rebleeding or shunt occlusion. Distal splenorenal shunts (p = 0.004) and nonselective shunts (p = 0.001) were more protective against rebleeding than was esophagogastric devascularization. CONCLUSIONS: The sequential introduction of endoscopic therapy, liver transplantation, and TIPS has resulted in better selection and improved results with respect to quality and length of survival for patients treated surgically for variceal bleeding. Despite these innovations, portosystemic shunts and esophagogastric devascularization remain important and effective options for selected patients with bleeding secondary to portal hypertension.     

Management of esophageal varices in children by endoscopic variceal ligation

Endoscopic variceal sclerotherapy (EVS) has been considered the mainstay of therapy for bleeding esophageal varices in adults. However, recent data have shown that endoscopic variceal ligation (EVL) is just as efficacious and has fewer complications than EVS. Although there are many reports concerning EVL in adults, only a few studies have been done in children. This report describes experience with EVL in 22 children with esophageal variceal hemorrhage. Eighty-seven EVL procedures were performed during a 9-year period in 22 children. The causes of portal hypertension were biliary atresia (10), portal vein thrombosis (8), chronic active hepatitis (1), cirrhosis secondary to cystic fibrosis (2), and primary sclerosing cholangitis (1). The age range at the onset of variceal bleeding was 8 months to 19 years. Twelve patients had EVS before EVL treatment was begun. Distal esophageal varices (one to four per session) were mechanically ligated using an elastic band ligature device attached to a flexible endoscope. The aim of therapy was obliteration of distal esophageal varices by EVL, every 2 to 4 weeks, until eradication. Subsequent EVL was dictated by the status of the varices. Outcome was assessed with respect to survival, rebleeding, status of varices, and complications. The patients underwent a mean of four sessions of EVL (range, one to eight). Four patients subsequently underwent liver transplantation. Of the 18 patients remaining (average follow-up period, 5.3 years), 12 had their varices eradicated (average of four EVL sessions), four are still in treatment, one has not been evaluated in the past 4 years, and one died of liver failure. Complications included bleeding between sessions (6 patients), cervical esophageal perforation (1 patient), and transient fever (2 patients). No child has experienced symptoms of esophageal stenosis or gastroesophageal reflux. Two patients died of liver disease, unrelated to bleeding from portal hypertension. EVL is effective in controlling variceal hemorrhage in children with portal hypertension, regardless of etiology. The complication rate is low, and EVL is an acceptable and perhaps preferable alternative to EVS in children with esophageal varices.     

Effects of transjugular intrahepatic portosystemic shunt (TIPS) on quantitative liver function tests

BACKGROUND/AIMS: The transjugular intrahepatic portosystemic stent-shunt (TIPS) has been established as a new effective treatment for portal hypertension in advanced liver disease. Impairment of liver function due to reduced portal venous perfusion is considered to be a major risk of TIPS, and the shunt leads to an increase in the incidence of hepatic encephalopathy (HE). Known complications, like the increase in the incidence of HE or TIPS stenosis, are diagnosed either clinically or by doppler ultrasound. It is not practicable to use quantitative liver function tests in the diagnostic work-up of HE, and medical or interventional therapy can be established after clinical diagnosis. Still, information is limited about the influence of TIPS on quantitative liver function tests in patients with liver cirrhosis. Therefore, the aim of this prospective study was to assess the effects of TIPS on various liver function tests. METHODOLOGY: Fifteen patients with liver cirrhosis, a hepatopetal portal flow before TIPS, and an uncomplicated course without stenosis after elective TIPS were analysed. Liver function was quantitatively measured using the [14C]aminopyrine breath test (ABT), considered to be independent of hepatic blood flow, the monoethylglycinexylidide test (MEGX), believed to be largely dependent on hepatic blood flow, serum bilirubin, serum albumin, and prothrombin time. Measurements were performed before, 1, 3 and 6 months after TIPS. RESULTS: TIPS decreased the portal venous pressure gradient from 31.0+/-2.0 cm (SEM) H2O to 16.9+/-1.8 cm H2O (p<0.01). One, 3 and 6 months after TIPS there was no significant deterioration of liver function as assessed by ABT, MEGX or serum bilirubin, serum albumin, and prothrombin time compared to baseline values before TIPS. ABT and MEGX were significantly correlated before TIPS (r=0.72; p<0.01) and after TIPS (r=0.76; p<0.05). CONCLUSIONS: These data show no significant deterioration of microsomal liver function as measured by the quantitative liver function tests ABT and MEGX over a period of 6 months after elective TIPS. In particular, there was no significant reduction of the MEGX-test considered to depend predominantly on hepatic blood flow. Thus, there is no need for the quantitative liver function tests ABT and MEGX in the routine management of patients following the TIPS procedure.     

Prospective randomized comparison of surgical versus endovascular management of thrombosed dialysis access grafts

PURPOSE: Salvage of thrombosed prosthetic dialysis shunts can be performed using surgical or endovascular techniques. A prospective randomized trial was designed to compare the efficacy of these two methods in restoring dialysis access function. METHODS: One hundred fifteen patients with thrombosed dialysis shunts were randomized prospectively to surgical (n = 56) or endovascular (n = 59) therapy. In the surgical group, salvage was attempted with thrombectomy alone in 22% and with thrombectomy plus graft revision in 78%. In the endovascular group, graft function was restored with mechanical (82%) or thrombolytic (18%) graft thrombectomy followed by percutaneous angioplasty. RESULTS: Stenosis limited to the venous anastomotic area was the cause of shunt thrombosis in 55% of patients, and long-segment venous outflow stenosis or occlusion was the cause in 30%. In 83% of the surgical group and in 72% of the endovascular group, graft function was immediately restored (p = NS). The postoperative graft function rate was significantly better in the surgical group (p < 0.05). Thirty-six percent of grafts managed surgically remained functional at 6 months and 25% at 12 months. In the endovascular group, 11% were functional at 6 months and 9% by 12 months. Patients with long-segment venous outflow stenosis or occlusion had a significantly worse patency rate than those with venous anastomotic stenosis (p < 0.05). CONCLUSIONS: Neither surgical nor endovascular management resulted in long-term function for the majority of shunts after thrombosis. However, surgical management resulted in significantly longer primary patency in this patient population, supporting its use as the primary method of management in most patients in whom shunt thrombosis develops.     

Ultrasonography of the ureters

Ultrasonography is a rapid, accurate, noninvasive diagnostic test for primary (congenital) and secondary (acquired) portosystemic shunting in dogs and cats. Two-dimensional, gray-scale ultrasonography alone enables diagnosis of most congenital portosystemic shunts and determination of intra- versus extrahepatic location. Use of duplex- and color-flow Doppler ultrasonography aids detection of congenital and acquired extrahepatic portosystemic shunts. The underlying cause of acquired portosystemic shunting is portal hypertension; this may be documented by finding either hepatofugal or reduced velocity hepatopetal portal blood flow by duplex-Doppler. Also, ultrasonography may enable detection of lesions involved in the pathogenesis of portal hypertension, for example, hepatic arterioportal fistula, hepatic parenchymal lesions, and portal vein thrombosis.     

Identification of dipeptidyl peptidase IV as the antigen of a monoclonal anti-prostasome antibody

Two patients with previous distal splenorenal shunts (DSRSs) performed 6 years earlier underwent liver transplantation (LT). A preoperative selective mesenteric artery angiogram showed collateral veins draining mesenteric venous flow into the shunt. Intraoperative flow measurements were performed to assess the steal of portal venous flow by the shunt and determine the need for shunt occlusion. Portal vein, hepatic artery, and shunt flows were measured by ultrasound transit-time flow probes in the native liver and after graft implantation with and without temporary shunt occlusion. Hemodynamic studies showed that long-standing DSRSs are high-flow shunts that steal portal flow. After graft implantation, DSRS flows remained high. Occlusion of the shunts produced an increase in portal vein flow at an amount similar to those of splenorenal shunt. Thus, the flow measurements showed persistent steal by the shunts after graft implantation and, therefore, the DSRSs were occluded but splenectomy was not performed. We conclude that the decision to occlude a DSRS should be based on the demonstration of steal of portal flow by the shunt and reversibility once the shunt is occluded. Splenectomy is not required when the DSRS is occluded.     

Recanalized umbilical vein in portal hypertension

Experience with splenoportography suggests that patency of the umbilical vein occurs in about 9% of the patients with portal hypertension. A widely patent umbilical vein might serve as a decompressive portosystemic shunt. Percutaneous transhepatic portography was performed in 107 patients with cirrhosis of the liver and portal hypertension. A patent umbilical vein was found in 28 patients (26%). This finding significantly paralleled the number and size of other collateral veins, apart from gastroesophageal varices. No significant relation was found between umbilical vein patency and portal pressure, extrahepatic shunting, variceal bleeding, or ascites. It is concluded that a large patent umbilical vein does not effectively relieve portal hypertension, prevent gastroesophageal varices, or protect against variceal bleeding or ascites.     

The heterogenous nature of in vivo basal cell carcinoma

The effects of tetramethylpyrazine, an alkaloid isolated from a Chinese herb Ligusticum wallichii Franch have been assessed in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation in Sprague-Dawley rats. Two weeks after ligation, when the hyperdynamic state had stabilized, rats were anaesthetized after an overnight fast and cannulated for measurement of mean arterial pressure, portal venous pressure, cardiac index and heart rate. Tetramethylpyrazine (3.0, 9.9 and 30mgkg(-1)) induced dose-dependent reductions of portal venous pressure and mean arterial pressure after intravenous infusion. The maximum percentage reduction of portal venous pressure after tetramethylpyrazine was 6.0+/-0.8, 9.3+/-1.6 and 20+/-2% of baseline for doses of 3.0, 9.9 and 30.0mgkg(-1), respectively. Also, total peripheral resistance was significantly reduced by tetramethylpyrazine and cardiac index was slightly increased. Our results showed that tetramethylpyrazine induced portal pressure reduction in portal hypertensive rats.     

The abnormal hepatic scan of chronic liver disease: its relationship to hepatic hemodynamics and colloid extraction

To help explain the characteristic hepatic scan pattern of chronic liver disease, the degree of scan abnormality (scan score, SS) after administration of technetium-99m sulfur colloid (Tc) was compared with data obtained at hepatic vein catheterization in 28 patients. Although SS showed a correlation with wedged hepatic vein pressure (r = +0.491), the scan abnormality was not directly due to portal hypertension because it remained unchanged when the latter was relieved by portacaval shunt. Also, the scan abnormality was found to be unrelated to a low hepatic blood flow. Scan abnormality was not attributable primarily to hyperactivity of the reticuloendothelial (RE) cells of the spleen and bone marrow since fractional clearance (K) of Tc from the blood was decreased rather than increased in patients with abnormal scans. SS was inversely correlated with K or Tc (r = -0.575) and with hepatic extraction efficiency for Tc (r = -0.673), showing that the basic abnormality was poor extraction of the colloid by the RE cells of the liver with a resultant increase in the amount available for extrahepatic localization. Indirect evidence suggests that this poor extraction of colloid is due to intrahepatic shunts bypassing hepatic RE cells.     

Transjugular intrahepatic portosystemic shunts (TIPS) in children

The transjugular intrahepatic portosystemic shunt procedure is an accepted treatment for adults with complications of portal hypertension. We performed a retrospective review of all pediatric TIPS placements performed at the University of California, San Francisco between 1990 and 1996. Twelve procedures were attempted in nine children, with a mean age (+/- SD) of 9.4 +/- 3.9 years (range, 5 to 15 years) and a mean weight of 31 +/- 18 kg (range, 16 to 70 kg). The indications for TIPS placement were portal hypertension complicated by chronic variceal hemorrhage not controlled with sclerotherapy (n = 7) and hypersplenism with thrombocytopenia (n = 2). TIPS placement was successfully completed initially in seven of nine (78%) patients. Unfavorable vascular anatomy was the cause of failure in two cases. The seven patients who underwent successful TIPS placement were followed up for an average of 136 days (range, 1 to 800 days); two still have patent shunts, three underwent liver transplantation, one had a splenorenal shunt after stenosis, and one died of underlying liver disease. Variceal bleeding was controlled in four of five patients who successfully underwent TIPS placement. Shunt occlusion occurred in four patients; patency was restored by transjugular shunt revision in three, and a splenorenal shunt was performed in one.     

Doppler-duplex ultrasonography in the diagnosis of cavernous portal vein

Prehepatic portal hypertension caused by cavernous transformation of the portal vein has been more and more considered as a multiorgan disease with circulatory changes in numerous organs related to systemic and splanchnic vascular network [1]. Honeycomb-like, spongy, cavernous portal vein is a rare clinical and pathoanatomical entity which usually results from portal vein thrombosis. Recanalization and neovascularization processes lead to cavernomatous transformation of the portal vein lumen and formation of periportal collateral hepatopetal venous varices (Petren's veins) [5, 6]. Recently, with Doppler ultrasonography and angiography cavernous portal vein has been identified as the cause of prehepatic portal hypertension. Usage of color Doppler and duplex Doppler ultrasonography has greatly contributed to diagnostic efficiency, while therapeutically, the disease remains a serious and controversial problem. METHODS: At the Institute of Digestive Diseases, Clinical Centre of Serbia, 8 patients with cavernous portal vein were studied in the period 1995-1997. Real-time duplex and color Doppler ultrasonography (Toshiba-SSA 100A with sector duplex probe 3.75 MHz, and 9 ATL with color Doppler convex duplex probe 3.5 MHz) were used. Indirect (arterial) portography was used for imaging of lienoportal system in the venous phase of angiography as follows: catheterization (Seldinger's technique) of the coeliac trunk or lienal artery, and catheterization of the superior mesenteric artery. Indirect portography was performed by injection of 60-80 ml of the contrast medium by an automatic pump, at 10-14 ml/sec, i.e. 8-10 ml/sec by the digital technique [7]. Peroral fiberendoscopy was performed in all patients by Olympus GIF-XQ 10 endoscope. RESULTS: In our study the conventional ultrasonographic examination failed to provide an appropriate image of the normal portal vein. In hepatoduodenal ligament multiple tubular and round structures were seen, revealing an atypical honeycomb or spongycavernous shape of the venous lumen (Figs. 1 and 2). Doppler ultrasonography of the lumen of these venous collateral structures revealed a continuous, hypokinetic flow, mid-rate 7.4 cm/sec, which was always hepatopetally directed (to the liver). Color Doppler ultrasonography detected extensive portosystemic collateralls in all patients, and varices in the gallbladder wall in 1 patient. The results of indirect portography correlated well with Doppler ultrasonographic findings. In all patients hepatopetal flow was found (Figs. 3 and 4). The aetiology was diverse: idiopathic, liver cirrhosis, haematological diseases, Crohn's disease and Marfan's syndrome. Two patients had IV degree varices in the distal third of the oesophagus, and 4 patients had II/III degree varices. Patients with posthepatic liver cirrhosis and Crohn's disease had no varices in the distal third of the oesophagus and gastric fornix. DISCUSSION: Since Pick (1909) described this malformation as the hepatopetal collateral, the haemodynamic concept of this entity has not been changed. Doppler ultrasonography and angiography confirm that the blood flow in cavernomas is hepatopetal, i.e. compensated and functional. Cavernous transformation of the portal vein is clinically manifested by bleeding from oesophagogastric varices. Haemathemesis is the most alarming complication and may be the first clinical sign. The haemorrhage is usually recurrent and profuse, but in most cases it is tolerated well owing to preserved hepatic function in patients without liver cirrhosis [19]. Portosystemic collateral circulation may take place via retroperitoneal and other spontaneous venous shunts, not involving the left gastric vein or vv. gastricae breves, when oesophagogastric varices are absent (our patient with Crohn's disease and posthepatitic B cirrhosis). Splenomegaly with hypersplenism is always present with cavernous transformation of the portal vein, and usually precedes the occurrence of gastrointestinal hae