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Pressure Gradient Measurement (pressure + gradient_measurement)
Selected AbstractsIncreasing dimethylarginine levels are associated with adverse clinical outcome in severe alcoholic hepatitis,HEPATOLOGY, Issue 1 2007Rajeshwar P. Mookerjee Previous studies suggest reduced hepatic endothelial nitric oxide synthase activity contributes to increased intrahepatic resistance. Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, undergoes hepatic metabolism via dimethylarginine-dimethylamino-hydrolase, and is derived by the action of protein-arginine-methyltransferases. Our study assessed whether ADMA, and its stereo-isomer symmetric dimethylarginine (SDMA), are increased in alcoholic hepatitis patients, and determined any relationship with severity of portal hypertension (hepatic venous pressure gradient measurement) and outcome. Fifty-two patients with decompensated alcoholic cirrhosis were studied, 27 with acute alcoholic hepatitis and cirrhosis, in whom hepatic venous pressure gradient was higher (P = 0.001) than cirrhosis alone, and correlated with ADMA measurement. Plasma ADMA and SDMA were significantly higher in alcoholic hepatitis patients and in nonsurvivors. Dimethylarginine-dimethylamino-hydrolase protein expression was reduced and protein-arginine-methyltransferase-1 increased in alcoholic hepatitis livers. ADMA, SDMA and their combined sum, which we termed a dimethylarginine score, were better predictors of outcome compared with Pugh score, MELD and Maddrey's discriminant-function. Conclusion: Alcoholic hepatitis patients have higher portal pressures associated with increased ADMA, which may result from both decreased breakdown (decreased hepatic dimethylarginine-dimethylamino-hydrolase) and/or increased production. Elevated dimethylarginines may serve as important biological markers of deleterious outcome in alcoholic hepatitis. (HEPATOLOGY 2007;45:62,71.) [source] Performance of Doppler ultrasound in the prediction of severe portal hypertension in hepatitis C virus-related chronic liver diseaseLIVER INTERNATIONAL, Issue 10 2007Francesco Vizzutti Abstract Purpose: To evaluate the correlation between hepatic vein pressure gradient measurement and Doppler ultrasonography (DUS) in patients with chronic liver disease (CLD). Patients and methods: Sixty-six patients with fibrotic to cirrhotic hepatitis C virus-related CLD, were consecutively included upon referral to our haemodynamic laboratory. Superior mesenteric artery pulsatility index (SMA-PI), right interlobar renal and intraparenchymal splenic artery resistance indices, were determined, followed by hepatic venous pressure gradient (HVPG) measurement. Results: A correlation was found between HVPG and intraparenchymal splenic artery resistance index (SA-RI) (r=0.50, P<0.0001), SMA-PI (r=,0,48, P<0.0001), right interlobar renal artery resistance index (RRA-RI) (r=0.51, P<0.0001) in the whole patient population. However, dividing patients according to the presence/absence of severe portal hypertension (i.e. HVPG ,12 mmHg), a correlation between HVPG and intraparenchymal SA-RI (r=0.70, P<0.0001), SMA-PI (r=,0.49, P=0.02), RRA-RI (r=0.66, P=0.0002) was observed only for HVPG values <12 mmHg. HVPG but not DUS correlated with the presence of esophageal varices (P<0.0001). Conclusions: Superior mesenteric artery pulsatility index, intraparenchymal splenic and right interlobar renal artery resistance indices do not adequately predict severe portal hypertension. [source] Dialysis Reduces Portal Pressure in Patients With Chronic Hepatitis CARTIFICIAL ORGANS, Issue 7 2010Sandeep Khurana Abstract The purpose of this study was to characterize changes in hepatic venous pressures in patients with chronic hepatitis C. The histology and laboratory data from patients with chronic hepatitis C who underwent a transjugular liver biopsy (TJLB) and hepatic venous pressure gradient measurement were analyzed. Portal hypertension was defined as hepatic venous pressure gradient ,6 mm Hg. A single pathologist masked to hepatic venous pressure gradient scored liver sections for inflammation and fibrosis. The patients with high-grade inflammation (relative risk [RR] 2.82, P = 0.027, multivariate analysis) and late-stage fibrosis (RR 2.81, P = 0.022) were more likely to have a hepatic venous pressure gradient ,6 mm Hg, while the patients on dialysis (RR 0.32, P = 0.01) were less likely to have a hepatic venous pressure gradient ,6 mm Hg. The patients on dialysis (n = 58) had an elevated serum blood urea nitrogen and creatinine when compared with those who were not (n = 75) (47.6 ± 3.3 and 7.98 ± 0.4 vs. 25.9 ± 2.0 and 1.66 ± 0.22 mg/dL, respectively; P < 0.001). While the hepatic venous pressure gradient increased with the rising levels of liver fibrosis in the latter group (P < 0.01), it did not change in the patients on dialysis (P = 0.41). The median hepatic venous pressure gradient was especially low in late-stage fibrosis patients on dialysis when compared with the latter group (5 vs. 10 mm Hg, P = 0.017). In patients on dialysis, serum transaminases were low across all levels of fibrosis. Twenty-three of the 92 patients with early fibrosis had a hepatic venous pressure gradient ,6 mm Hg. In patients with chronic hepatitis C, concomitant TJLB and hepatic venous pressure gradient measurement identify those who have early fibrosis and portal hypertension. Long-term hemodialysis may reduce portal pressure in these patients. [source] Comparison study of Doppler ultrasound surveillance of expanded polytetrafluoroethylene-covered stent versus bare stent in transjugular intrahepatic portosystemic shuntJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2010Qian Huang MD Abstract Objective. This prospectively randomized controlled study aimed to assess with Doppler ultrasound (US) the shunt function of expanded polytetrafluoroethylene (ePTFE)-covered transjugular intrahepatic portosystemic shunt (TIPS) stent versus bare stent and to evaluate the usefulness of routine TIPS follow-up of ePTFE-covered stents. Methods. Sixty consecutive patients were randomized for bare or covered transjugular TIPS stenting in our institution between April 2007 and April 2009. Data of follow-up Doppler US, angiography, and portosystemic pressure gradient measurements were collected and analyzed. Results. The follow-up period was 8.34 ± 4.42 months in the bare-stent group and 6.16 ± 3.89 months in the covered-stent group. Baseline clinical characteristics were similar in both groups. Two hundred three US studies were performed in 60 patients, with a mean of 3.4 per patient, and demonstrated abnormalities in 28 patients (21 bare stents, 7 ePTFE-covered stents), 19 of them (13 in bare-stent group, 6 in covered-stent group) showing no clinical evidence of recurrence. Ten of 13 patients in the bare-stent group underwent balloon angioplasty or additional stent placement, whereas only one of six patients in the covered-stent group needed reintervention for intimal hyperplasia. The average peak velocity in the midshunt of ePTFE-covered stent was 139 ± 26 cm/s after TIPS creation and 125 ± 20 cm/s during follow-up, which was significantly higher than the bare-stent group (p < 0.05). The main portal vein and hepatic artery showed higher flow velocities in the ePTFE-covered stent group than in the bare-stent group. ePTFE-covered stents maintained lower portosystemic pressure gradient than bare stents (9.5 ± 2.9 versus 13.2 ± 1.5 mmHg, p < 0.05). Conclusions. ePTFE-covered stents resulted in higher patency rates and better hemodynamics than bare stents. Routine US surveillance may not be necessary in patients with ePTFE-covered TIPS stent. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound 38:353-360, 2010 [source] | ||||||||||