Renovascular impedance and esophageal varices in patients with Child-Pugh class A cirrhosis

Non-invasive tests for the detection of oesophageal varices in compensated cirrhosis: systematic review and meta-analysis

INTRODUCTION

Conclusive data on the accuracy and clinical applicability of non-invasive screening tests for oesophageal varices (OV) in patients with compensated cirrhosis remain lacking. We conducted this study to identify currently available tests, estimate their diagnostic performance and then exemplify how these could be utilized in clinical practice.

MATERIALS AND METHODS

A systematic literature search was performed to identify all primary studies that reported accuracy using oesophagogastroduodenoscopy (OGD) as the gold standard. Sources searched included Ovid MEDLINE, Ovid EMBASE and The Cochrane Library databases.

RESULTS

Twenty-one studies with a total of 2471 patients were identified. Several tests were evaluated in more than three studies. Platelet count/spleen diameter ratio (PSR) had the highest summary area under the curve for detection of any size OV of 0.85 (95% confidence interval 0.78-0.92). At a cut-off of 909 (n = 4 studies) and prevalence rates of 10, 20, 30, 40 and 50% for OV, PSR screening correctly avoided the need for OGD in 70, 62, 55, 47 and 39% of patients, respectively.

CONCLUSIONS

PSR appears to be the most accurate and validated non-invasive screening test for OV in patients with compensated cirrhosis. At a cut-off of 909, PSR could be clinically useful to avoid OGDs in a significant proportion of patients.

Νon-invasive screening for esophageal varices in patients with liver cirrhosis

Esophageal varices are one of the main complications of liver cirrhosis. Upper gastrointestinal endoscopy is the gold standard for the detection of esophageal varices. Many less invasive methods for screening of varices have been investigated and the most recent Baveno VI guidelines suggest that endoscopy is not necessary in patients with liver stiffness <20 kPa and platelets >150,000/μL. A critical review of the literature was performed concerning non-invasive or minimally invasive methods of screening for esophageal varices. Liver and spleen elastography, imaging methods including computed tomography, magnetic resonance imaging and ultrasound, laboratory tests and capsule endoscopy are discussed. The accuracy of each method, and its advantages and limitations compared to endoscopy are analyzed. There are data to support the Baveno VI guidelines, but there is still a lack of large prospective studies and low specificity has been reported for the liver stiffness and platelet count combination. Spleen elastography has shown promising results, as there are data to support its superiority to liver elastography, but it needs further assessment. Computed tomography has shown high diagnostic accuracy and can be part of the diagnostic work up of cirrhotic patients in the future, including screening for varices.

A novel scoring system for prediction of esophageal varices in critically ill patients

Background and aims

Patients with advanced systemic illness or critically ill patients may present with upper gastrointestinal tract (GIT) bleeding which may need endoscopic intervention; however, this may expose them to unnecessary endoscopy. The aim was to validate a novel scoring system for risk stratification for urgency of GIT endoscopy in critically ill patients.

Methods

This is an observational study conducted from January 2013 to January 2016 to analyze 300 patients with critical medical conditions and presenting with upper gastrointestinal bleeding. Meticulous clinical, laboratory, and sonographic evaluations were performed to calculate Glasgow Blatchford score (GBS) and variceal metric score for risk stratification and prediction of the presence of esophageal varices (OV). Finally, this score was applied on a validation group (n=100).

Results

The use of GBS and variceal metric scores in critically ill patients revealed that patients who showed a low risk score value for OV (0-4 points) and GBS <2 can be treated conservatively and discharged safely without urgent endoscopy. In patients with a low risk for varices but GBS >2, none of them had OV on endoscopy. In patients with intermediate risk score value for OV (5-8 points) and with GBS >2, 33.33% of them had varices on endoscopy. In patients with high risk score value for varices (9-13) and GBS >2, endoscopy revealed varices in 94.4% of them. Finally, in patients with very high risk score for varices (14-17), endoscopy revealed varices in 100% of them.

Conclusion

GBS and variceal metric score were highly efficacious in identifying critically ill patients who will benefit from therapeutic endoscopic intervention.

Vascular Doppler ultrasonographic indices in cirrhosis: a case-control study with emphasis on the common carotid arteries

PURPOSE

To compare vascular Doppler waveform indices, particularly in the common carotid arteries, between cirrhotic and healthy subjects.

MATERIALS AND METHODS

A total of 60 patients with Class-B cirrhosis and 60 healthy matched counterparts were enrolled in this prospective study. Vascular Doppler waveform parameters including resistance and/or pulsatility indices (RI and PI, respectively) were obtained from the common carotid, renal, celiac, superior mesenteric, femoral and brachial arteries.

RESULTS

Compared to patients, healthy subjects had significantly higher mean PI and RI obtained from the common carotid (1.53 ± 0.20 vs. 1.43 ± 0.14, p = 0.03; 0.75 ± 0.02 vs. 0.72 ± 0.02, p < 0.001, respectively) and celiac arteries (2.00 ± 0.36 vs. 1.81 ± 0.34, p = 0.03; 0.80 ± 0.03 vs. 0.78 ± 0.02, p < 0.001, respectively). Both the mean PI and RI derived from the renal arteries, in contrast, were significantly higher in patients compared to that in controls (1.05 ± 0.13 vs. 1.11 ± 0.07, p = 0.03; 0.59 ± 0.03 vs. 0.63 ± 0.03, p < 0.001, respectively). The mean vascular impedance values obtained from the remaining arteries were comparable between the two groups.

CONCLUSIONS

Blood flow increases in the common carotid and celiac arteries of Class-B cirrhotic patients with elevated renovascular impedance.

Abnormal renal resistive index in patients with mild-to-moderate chronic obstructive pulmonary disease

BACKGROUND

Arterial rigidity and endothelial dysfunction are systemic manifestations of chronic obstructive pulmonary disease (COPD). The decrease in renal vascular resistance in order to adapt the increase in glomerular filtration rate after oral protein loading is known as normal renal functional reserve. We tested the hypothesis that COPD patients, even in those with mild-to-moderate airflow obstruction, are affected by systemic inflammation associated with abnormal renal functional reserve.

MATERIALS AND METHODS

The study enrolled 24 current smokers with a cigarette smoking history ≥ 25 pack-years and 8 nonsmokers with normal spirometry as control. Doppler sonography detected the renal resistive index (RRI) before and after oral protein loading to determine the renal functional reserve. Pulmonary function and serum tumor necrosis factor α (TNF-α) levels were analyzed to compare with the renal functional reserve.

RESULTS

The smokers were stratified into 3 groups (Group 1: smokers with normal spirometry, Group 2: mild COPD, Group 3: moderate COPD); nonsmokers as Group 4. The baseline RRI levels were similar in Group 1 and Group 4. After protein loading, the RRI elevated in all smoking groups; moreover, Group 3 had the highest RRI and with longer duration than other groups. The smokers with higher serum TNF-α levels had a longer RRI elevation. Multiple linear regression revealed forced expiratory volume in one second (FEV1), serum TNF-α levels and aging were independently predictive factors of impaired renal functional reserve.

CONCLUSIONS

A greater impairment in renal functional reserve of COPD patients was correlated with more severe airway obstruction and inflammation.

Doppler parameters of hepatic and renal hemodynamics in patients with liver cirrhosis

Introduction. There are limited studies on simultaneous evaluation of liver and renal blood flow using Doppler methods. We evaluated and compared the changes of liver and renal Doppler US parameters in patients with liver cirrhosis according to the degree of liver disease. Material and Methods. We assessed a large spectrum of liver and renal Doppler US parameters in 67 patients with liver cirrhosis. Results. Significant differences between Child's classes or score, as well as MELD score, were observed in all investigated intrarenal blood flow Doppler US parameters, except renal artery peak systolic velocity, but only in some of the hepatic ones. The deviations of renal Doppler US parameters were also related with the complications of liver cirrhosis, as well as serum urea and creatinine levels. There was relationship between Doppler US parameters of hepatic artery and the corresponding renal artery Doppler US parameters. The changes of Doppler US parameters were age independent. Conclusion. Our results show, renal Doppler US parameters correlate with the severity and complications of liver cirrhosis. Because of dynamic deviations of renal Doppler US parameters with advance of liver cirrhosis, we recommend Doppler US of renal artery as a part of follow up of these patients.

Renal haemodynamics in patients with liver cirrhosis assessed by colour ultrasonography

Colour Doppler flow imaging was used in this prospective, cross-sectional study to analyse renal haemodynamics in 50 cirrhotic patients and 15 healthy controls. Mean renal arterial resistive index (RI) was higher in cirrhotic patients than in healthy controls. Mean RI was also higher in cirrhotic patients with non-refractory ascites than in those without ascites, suggesting that the degree of renal vasoconstriction varies with the severity of ascites. A gradient of RI values across the main renal artery, interlobar artery and interlobular renal artery was retained in cirrhotic patients even in the decompensatory stage with non-refractory ascites but was not present in the decompensatory stage with refractory ascites. The disappearance of this gradient may be an important prognostic factor in the development of hepatorenal syndrome (HRS). An inverse correlation between creatinine clearance and interlobular arterial RI was shown for all cirrhotic patients suggesting that even patients with refractory ascites are in a prophase of HRS.

Performance of Doppler ultrasound in the prediction of severe portal hypertension in hepatitis C virus-related chronic liver disease

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 > or =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.

Renovascular Impedance Correlates with Portal Pressure in Patients with Liver Cirrhosis

PURPOSE

To prospectively evaluate, in patients with liver cirrhosis, the correlation between the renovascular impedance measured by using color flow and pulsed wave Doppler ultrasonography (US) and the portal pressure measured by using the hepatic venous pressure gradient (HVPG).

MATERIALS AND METHODS

The study was approved by the senior staff committee (comparable to institutional review board) of the university hospital, and written informed consent was obtained from all patients. Thirty-one patients with cirrhosis (22 men, nine women; mean age, 57.6 years +/- 8.8 [standard deviation]) and esophageal varices were consecutively enrolled in the study. Having fasted, the patients underwent color flow and pulsed wave Doppler US of the right interlobar renal artery (RRA) and the left interlobar renal artery (LRA). The resistance index (RI) and pulsatility index (PI) were determined. On the same day, with fluoroscopic guidance, a 5-F balloon-tipped catheter was advanced, via the right basilic vein, into the right hepatic vein; HVPG was calculated as the difference between the wedged and free hepatic pressures. All measurements were performed in triplicate, and permanent tracings were recorded. Correlations were made by using the Pearson test. The positive predictive value of renovascular impedance for detection of severe portal hypertension was determined.

RESULTS

Mean RI and PI values were 0.67 +/- 0.07 and 1.21 +/- 0.25, respectively, for the RRA, and 0.68 +/- 0.07 and 1.24 +/- 0.26, respectively, for the LRA. All patients had portal hypertension (mean HVPG, 19.3 mm Hg +/- 4.7; range, 11.5-33.5 mm Hg). Neither portal pressure nor renal impedance correlated with Child-Pugh score for cirrhosis. Renal artery impedance indexes correlated with the HVPG (for RRA RI: R = 0.424, P = .03; for RRA PI: R = 0.402, P = .04; for LRA RI: R = 0.352, P = .05; for LRA PI: R = 0.393, P = .02). A higher-than-normal renal impedance had a high positive predictive value (RRA RI and PI, 100%; LRA RI, 92%; LRA PI, 84%) for the detection of severe portal hypertension.

CONCLUSION

Renovascular impedance had a direct correlation with HVPG.

Renal resistive indexes and some renal functions in liver cirrhotic children

BACKGROUND

The aim of the present study was to investigate renal vascular resistive changes in children with different stages of liver cirrhosis without obvious renal failure.

METHODS

Twenty-nine children (14 girls, 15 boys, mean age 11.6 years) with cirrhosis and 20 healthy children (mean age 10.3 years) were investigated for renal vascular resistance with Doppler ultrasonography, urinary sodium, N-acetyl-beta-D glucosaminidase (NAG) and microalbuminuria excretion.

RESULTS

The measurements of renal resistive indexes (RRI) were significantly higher in cirrhotic patients than the control group (0.69 +/- 0.07 vs 0.62 +/- 0.02, P < 0.0001). RRI measurement was found to be increased in decompensated cirrhotic patients than in compensated cirrhotic patients (0.73 +/- 0.05 vs 0.67 +/- 0.08, P < 0.0001). A significant positive relationship was observed between RRI and child score (r = 0.53). Urine NAG/Cr ratio was significantly higher in cirrhotic patients than in the control subjects (P < 0.001). Microalbumin concentrations were increased in the patients with decompensated cirrhosis than in the controls (P = 0.02). Patients with ascites and portal hypertension showed increased RRI values.

CONCLUSIONS

We conclude that patients with cirrhosis are at risk of renal deterioration, which can not be detected by serum urea, creatinine, and glomerular filtration rate. The increase of RRI is associated with the progress of hepatocellular disease, and also the development of ascites and portal hypertension. Elevated urinary sodium excretion, elevated urinary NAG/Cr ratio and microalbuminuria might have a prognostic value especially in patients with Child scores> 6. Hence, monitoring RRI is a non-invasive means of studying early renal hemodynamic alteration in childhood cirrhosis.