Hepatic, splanchnic and systemic haemodynamic abnormalities in portal hypertension

Spleen stiffness: a new tool to predict high-risk varices in cirrhotic patients

INTRODUCTION

Cirrhosis is one of the major causes of morbidity and mortality worldwide. Portal hypertension is the major contributor of cirrhosis-related complications and is defined as a hepatic venous pressure gradient (HVPG) > 5 mmHg. Measurement of HVPG is an invasive, difficult, and costly procedure. Therefore, it is only performed in specialized centers. Liver stiffness measured with transient elastography is one of the most studied noninvasive markers of portal hypertension, and spleen elastography has recently emerged as an important adjuvant tool. The development of a new probe (100 Hz) that more reliably reflect the grade of portal hypertension evaluated by spleen stiffness measurement has improved the accuracy of this technique. The aim of this work was to evaluate the accuracy of spleen stiffness with the new dedicated probe to predict the presence of high-risk varices, as well as to determine the ideal cutoff to predict it.

METHODS

Prospective study of cirrhotic patients admitted to upper endoscopy that were also submitted to liver and spleen elastography with the 100-Hz probe by the same blinded operator in a tertiary center.

RESULTS

We included 209 cirrhotic patients, with mean age of 61.9 years (±9.9), 77.0% male. The most common etiology was alcoholic liver disease (72.7%). The median value of liver elastography was 25.3 [4.5-75] kPa, and the median value of spleen elastography was 42.4 [7.6-100] kPa. At the cutoff of 53.25 kPa, we obtained sensitivity of 100% and specificity of 72.6% to predict high-risk varices, and, according to this cutoff, 133/175 of esophagogastroduodenoscopy could have been spared (76.0%), while according to Baveno guidelines, only 51/175 would have been spared (29.1%).

CONCLUSION

In the era of noninvasive exams, spleen elastography with the 100-Hz probe emerges as an excellent tool for prediction of presence of high-risk varices. At the cutoff of 53.25 kPa, spleen elastography avoids upper endoscopy for screening for high-risk varices, promising to be become part of the hepatologists' daily routine.

Diagnosis, Treatment, and Management of Orthotopic Liver Transplant Candidates With Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is seen in 5-8% of orthotopic liver transplantation (OLT) candidates and has significant implications for clinical outcomes. POPH is characterized by vasoconstriction and remodeling of the pulmonary vasculature. It is exacerbated by the hyperdynamic circulation that is common in advanced liver disease. Screening all OLT candidates with transthoracic echocardiography to assess pulmonary pressures and right ventricular function is crucial, as clinical symptoms alone are not reliable. Any significant right ventricular dysfunction or dilatation along with an elevation in estimated pulmonary pressures usually triggers further investigation with right heart catheterization. The mainstays of therapy of POPH are vasodilators that are used in pulmonary arterial hypertension. They include monotherapy or combination therapy with prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors/guanylate cyclase stimulator. Limited evidence from smaller studies and case series suggests that a timely diagnosis of POPH and the early initiation of treatment improve patient outcomes, whether or not OLT is ultimately undertaken. Given the historically high perioperative mortality rate of more than 35%, POPH remains a contraindication to OLT unless it is treated and responsive to vasodilator therapy. We review the current literature and International Liver Transplant Society practice guidelines (2016) for the latest in understanding POPH, its pathogenesis, diagnosis, modern pharmacological treatment, indications, and contraindications for OLT, as well as perioperative management.

Medical management of ascites

INTRODUCTION

Ascites is a common complication of advanced cirrhosis that has a significant negative impact on survival. This review updates the reader on the medical management of ascites.

AREAS COVERED

This review explores the pathophysiology of ascites formation in cirrhosis; the current mainstays of medical management (treating the underlying cause of cirrhosis, avoiding nephrotoxic agents, sodium restriction, and combination diuretic therapy); potential novel agents, such as vasoconstrictors and vaptans; and albumin infusions. The literature research covers all aspects of medical management of ascites from the English literature, concentrating on publications from the past 10 years. It provides a thorough understanding of how the correction of pathophysiology of ascites formation helps to improve ascites; knowledge on the monitoring of patients with cirrhosis and ascites receiving medical management, and on prophylaxis against potentially life-threatening complication such as spontaneous bacterial peritonitis; and potential new treatments for ascites.

EXPERT OPINION

Management of patients with cirrhosis and ascites requires careful attention to fluid and electrolyte balance and avoidance of complications. Recognition of refractory ascites allows for the use of second-line treatments. All patients with cirrhosis and ascites should be considered for liver transplantation.

Lack of effect of norfloxacin on hyperdynamic circulation in bile duct-ligated rats despite reduction of endothelial nitric oxide synthase function: result of unchanged vascular Rho-kinase?

BACKGROUND/AIMS

In cirrhosis, portal hypertension is maintained by splanchnic vasodilation owing to overproduction of the vasodilator nitric oxide (NO) and defective contractile signalling by Rho-kinase. NO overproduction is partially caused by bacterial translocation from the gut to mesenteric lymph nodes. However, the effects of intestinal bacterial decontamination on hyperdynamic circulation or vascular contractility are unknown. We investigated the haemodynamic and vascular effects of norfloxacin in rats with secondary biliary cirrhosis.

METHODS

Cirrhosis was induced by bile duct ligation (BDL). One group was treated with norfloxacin (20 mg/kg/day, 5 days, orally). Bacterial growth in the lymph nodes was determined on blood agar plates. Invasive haemodynamic measurements were combined with coloured microspheres. Aortic contractility was assessed myographically. Protein expression/phosphorylation was examined by Western blot analysis.

RESULTS

Norfloxacin treatment of BDL rats abolished bacterial translocation to mesenteric lymph nodes. BDL rats had hyperdynamic circulation, including portal hypertension and splanchnic vasodilation. None of these parameters was changed by norfloxacin, although norfloxacin reduced endothelial NO synthase expression and phosphorylation. The latter was associated with a diminished activity of protein kinase G (PKG), which mediates NO-induced vasodilation. However, norfloxacin had no effect on aortic contractility to methoxamine or Ca2+, or the aortic expression of RhoA, Rho-kinase and beta-arrestin 2, or the phosphorylation of the Rho-kinase substrate moesin.

CONCLUSIONS

Short-term treatment of BDL rats with norfloxacin does not change hyperdynamic circulation or vascular contractility, despite reduction of PKG activity.

Portal hypertensive duodenopathy: clinical, endoscopic, and histopathologic profiles

OBJECTIVE

Description of the clinical, endoscopic, and histopathologic detailed profiles of duodenal affection in portal hypertensive patients.

METHODS

A total of 105 patients with chronic liver disease and portal hypertension (PH) were included, upper endoscopy was performed, and two duodenal biopsies were obtained from the bulb and distal to the ampulla, for histopathologic examination. Twenty dyspeptic patients with normal upper endoscopy were included as controls.

RESULTS

Of the portal hypertensive patients, 54 (51.4%) had endoscopic duodenopathy (ED) lesions including erythema, erosions, ulcers, telangiectasia, exaggerated villous pattern, duodenal varices, and mixed lesions. ED was significantly higher in patients having severe than mild gastropathy (56.8% vs 23.5%, P<0.05) with no relation to size of esophageal varices or variceal bleeding. ED was a source of overt bleeding in 6.7% and occult bleeding in 2.9% of patients. Histopathologically, vascular changes included either capillary congestion (in more than half of biopsies) or capillary angiogenesis (in more than one-quarter of biopsies). Nonvascular changes included increased apoptosis (in about 16% of biopsies), fibrous proliferation (in about 4% of biopsies), and villous changes (in 11.4% of distal biopsies). All changes were not statistically different between patients with and without ED. In dyspeptic patients, only minimal histopathologic changes were noted.

CONCLUSIONS

ED is significantly higher in patients with severe gastropathy and causes gastrointestinal bleeding in 9.5% of patients. Capillary angiogenesis is an important vascular mechanism for adaptation to PH. The overall existence of histopathologic duodenopathy is much higher than that of ED and occurs with a similar prevalence in patients with and without ED.

Effects of splenic artery occlusion on portal pressure in patients with cirrhosis and portal hypertension

The specific contribution of splenic blood inflow to portal hypertension in patients with cirrhosis is still unclear. In this study, we investigated this contribution by assessing the hemodynamic effects of transient splenic artery occlusion. In 15 cirrhotic patients, portal pressure gradient (PPG) was measured just before inserting a transjugular intrahepatic portosystemic shunt (TIPS), in baseline conditions, for 15 minutes after splenic artery occlusion and 5 minutes after recovery. Splenic artery occlusion caused a significant decrease in PPG (range, -4% to -38%, median -20%, P < 0.001) which promptly returned to baseline values after recovery of the splenic inflow. The decrease in PPG showed a significant correlation with spleen volume (r = 0.70, P < 0.005), liver volume (r = -0.63; P < 0.01), and spleen/liver volume ratio (r = 0.82, P < 0.001). Seven out of eight patients with a spleen/liver volume ratio greater than 0.5 had a marked decrease in PPG (>20%), whereas none of patients with a ratio lesser than 0.5 had a marked PPG response. In conclusion, in cirrhotic patients with portal hypertension, splenic artery occlusion causes a significant reduction in portal pressure (PPG). The drop in PPG is directly related to spleen volume and indirectly related to liver volume. The spleen/liver volume ratio accurately predicts the drop in PPG and may be used to identify patients who could obtain a significant advantage from surgical and nonsurgical procedures decreasing splenic inflow.

Non-pulsatile hepatic and portal vein waveforms in patients with liver cirrhosis: concordant and discordant relationships

The relationship between hepatic vein waveform and portal vein waveform (HVW and PVW) was evaluated in 54 healthy subjects and 148 patients with liver cirrhosis and portal hypertension using spectral Doppler ultrasound recordings. In all healthy subjects, the HVW was triphasic and the PVW was slightly pulsatile. 51 of 148 patients (34.5%) had flat non pulsatile HVW with a significantly higher incidence in Child C vs Child A patients (48.9% vs 20.7%, respectively; p<0.01) while 56 of 148 patients (37.8%) had flat PVW, also with significantly higher incidence in Child C vs Child A patients (46.7% vs 25.9%, respectively; p<0.05). Of the 86 patients having flat waves (HVW or PVW), only 21 (24.4%) had concordant flat waves (flat both HVW and PVW) while discordance was detected in the remaining 75.6% patients. Only 22 patients (14.9%) had a triphasic HVW but with broad spectrum and absent window in 20 (90.9%) and significantly lower pre-systolic:systolic (PS) ratio (Vmax of the pre-systolic retrograde wave/Vmax of the systolic antegrade wave) compared with healthy subjects (0.23+/-0.1 vs 0.42+/-0.18, respectively; p<0.001). In conclusion, spectral broadening with window absence and dampening of the retrograde pre-systolic wave mark are the earliest changes in HVW in cirrhotic patients even in the presence of a triphasic pattern. The transmission of hepatic vein pulsatility is not a major factor responsible for portal vein pulsatility.

Gastric mucosal resistance to acute injury in experimental portal hypertension

1. The gastric mucosa of portal hypertensive rats exhibits important microvascular changes and a nitric oxide (NO)-dependent hyperemia. This study analyses whether portal hypertensive mucosa exhibits changes in its ability to withstand aggression. 2. Portal hypertension was induced by partial portal vein ligation (PPVL) or common bile duct ligation (CBDL) and gastric damage was induced by oral administration of ethanol or aspirin. Experiments were performed in conscious or anaesthetized rats and some animals were pre-treated with the NO-synthesis inhibitor L-NAME. 3. Conscious PPVL or CBDL rats showed an increased resistance to the damaging effects of ethanol. Oral administration of aspirin produced less gastric damage in PPVL conscious rats than in the control group. 4. The protective effects of portal hypertension were maintained in animals anaesthetized with ketamine and absent when pentobarbital was employed. 5. Pre-treatment with L-NAME restored the damaging effects of ethanol and aspirin in PPVL rats without modifying the level of damage in control animals. 6. Gastric bleeding induced by oral aspirin, as measured by the luminal release of (51)Cr-labelled erythrocytes, was significantly greater in PPVL rats than in control animals. 7. Semi-quantitative analysis by RT--PCR of the mRNA for endothelial NO-synthase (eNOS), neuronal NOS (nNOS) and inducible NOS (iNOS) levels showed that the expression of iNOS was slightly increased in both the gastric mucosa and smooth muscle of PPVL rats. No changes were observed in eNOS and nNOS expression. 8. Conscious portal hypertensive rats exhibit an enhanced resistance to acute gastric damage which is absent under the influence of some types of anaesthesia and seems related to an increased synthesis of nitric oxide. However, mucosal lesions in these animals show an augmented bleeding per area of injury.

Renal effects of transjugular intrahepatic portosystemic shunt in cirrhosis: comparison of patients with ascites, with refractory ascites, or without ascites

Renal effects of the transjugular intrahepatic portosystemic shunt (TIPS) were compared in 6 patients without ascites (group 1), 11 patients with ascites responding to diuretic treatment (group 2), and 6 patients with refractory ascites (group 3). Seven days after insertion of TIPS, 24-hour urinary sodium excretion had increased in patients with ascites: 113 +/- 16 mmol to 170 +/- 30 mmol (P = .012) in group 2, and 22 +/- 8 mmol to 77 +/- 27 mmol (P = .050) in group 3. In group 3, fractional sodium excretion tended to increase from 0.26% +/- 0.14% to 0.62% +/- 18% (P = .081). The relative increase of urinary sodium excretion (to 444% +/- 122%) and fractional sodium excretion (to 413% +/- 127%) in group 3 was significantly (P < .05) higher than in group 1 and group 2, respectively. Creatinine clearance and 24-hour urinary volume were not significantly changed in either group. Patients with Child-Pugh class C had a more pronounced effect of TIPS on urinary sodium excretion (increase to 396% +/- 115% vs. 139% +/- 15%; P = .066) and on fractional sodium excretion (increase to 415% +/- 103% vs. 94% +/- 15%; P = .020) than patients with less-severe liver disease. Fractional sodium excretion of less than 0.35% before TIPS was found to be an indicator of renal response to TIPS. The effect of TIPS on urinary sodium excretion and on fractional sodium excretion was related to the patients' Child-Pugh score (r = .55; P = .007 and r = .68; P = .001, respectively) and inversely to their fractional sodium excretion (r = -.44; P = .047 and r = -.54; P = .012, respectively) before TIPS. These data demonstrate that TIPS affects renal sodium handling in patients with ascites, particularly in patients with refractory ascites. Severity of liver disease and fractional sodium excretion before TIPS are parameters to predict the extent of the renal response.

Pattern of sodium handling and its consequences in patients with preascitic cirrhosis

BACKGROUND/AIMS

The initial abnormalities in the renal sodium handling in patients with cirrhosis before developing ascites remain unknown. The aim of this study is to further characterize sodium metabolism and the effects of sodium loading in preascitic cirrhosis.

METHODS

Eight male, preascitic patients with cirrhosis and 6 volunteers had their daily urinary sodium excretion level measured while on a strictly metabolically controlled diet, first consisting of 20 mmol then of 200 mmol sodium per day each for 7 days. Central blood volume, plasma norepinephrine, and atrial natriuretic factor levels were measured during each diet.

RESULTS

Preascitic patients with cirrhosis had significantly less daily urinary sodium excretion on both diets. Volume expansion in the patients with cirrhosis was indicated by significantly greater weight gain and higher atrial natriuretic factor levels for each diet. Patients with cirrhosis had central blood volume expansion (1725 +/- 54 mL/m2) compared with controls (1495 +/- 81 mL/m2; P = 0.03) on a low-sodium diet. This increased significantly in the controls (1864 +/- 164 mL/m2; P = 0.04) on a high-sodium diet, associated with suppression of plasma norepinephrine, but not in the patients with cirrhosis (1679 +/- 107 mL/m2; P > 0.05).

CONCLUSIONS

Failure of further central blood volume expansion in the patients with cirrhosis on high-sodium diet in the presence of significant weight gain suggests maldistribution away from the effective arterial blood volume. This study provides further reasons why preascitic patients with cirrhosis might benefit from sodium restriction.