The Circulatory System in Liver Disease

Close Relationship between Systemic Arterial and Portal Venous Pressure in an Animal Model with Healthy Liver

It is unclear to what extent systemic arterial blood pressure influences portal pressure. This relationship is clinically important as drugs, which are conventionally used for therapy of portal hypertension, may also influence systemic arterial blood pressure. This study investigated the potential correlation between mean arterial (MAP) and portal venous pressure (PVP) in rats with healthy livers. In a rat model with healthy livers, we investigated the effect of manipulation of MAP on PVP. Interventions consisted of 0.9% NaCl (group 1), 0.1 mg/kg body weight (bw) Sildenafil (low dose), an inhibitor of phosphodiesterase-5 (group 2), and 1.0 mg/kg bw Sildenafil (high dose, group 3) in 600 µL saline injected intravenously. Norepinephrine was used to increase MAP in animals with circulatory failure while PVP was monitored. Injection of the fluids induced a transient drop in MAP and PVP, probably due to a reversible cardiac decompensation. The drop in MAP and drop in PVP are significantly correlated. The time lag between change in MAP and change in PVP by 24 s in all groups suggests a cause-and-effect relationship. Ten minutes after the injection of the fluid, cardiac function was normalized. Thereafter, MAP gradually decreased. In the NaCl group, PVP decreases by 0.485% for a 1% drop of MAP, by 0.550% in the low-dose sildenafil group, and by 0.651% in the high-dose sildenafil group (p < 0.05 for difference group two vs. group one, group three vs. group one, and group three vs. group two). These data suggest that Sildenafil has an inherent effect on portal pressure that exceeds the effect of MAP. Injection of norepinephrine led to a sudden increase in MAP followed by an increase in PVP after a time lag. These data show a close relationship between portal venous pressure and systemic arterial pressure in this animal model with healthy livers. A change in MAP is consequently followed by a change in PVP after a distinct time lag. This study, furthermore, suggests that Sildenafil influences portal pressure. Further studies should be performed in a model with cirrhotic livers, as these may be important in the evaluation of vasoactive drugs (e.g., PDE-5-inhibitors) for therapy of portal hypertension.

Congenital hypothyroidism: a case report of an Egyptian child with congenital heart disease, pelvic kidney and cavernous transformation of portal vein

Background

A case of thyroid hormone deficiency which presented at birth. Thyroid hormones are essential for brain development and normal cognitive function. Common symptoms of congenital hypothyroidism (CH) include constipation, decreased activity, increased sleep and feeding difficulty. Common signs include dry skin, macroglossia and umbilical hernia. If congenital hypothyroidism is left untreated after birth, it can lead to permanent intellectual disability and growth failure.

Case presentation.

Here, we report a 10.5-year-old female with the typical features of CH. She is the sixth in order of birth of consanguineous Egyptian parents. No family history of similar condition. Our patient had primary CH caused by thyroid agenesis. She had congenital heart disease, pelvic kidney, cavernous transformation of portal vein and parenchymatous liver disease.

Conclusions

Congenital hypothyroidism is associated with an elevated risk of congenital anomalies. Clinical suspicion of symptoms and signs of congenital hypothyroidism are important for early diagnosis and prevention of serious problems that are related to congenital hypothyroidism.

Impact of cardiac and noncardiac cirrhosis on coronary revascularization outcomes from the National Inpatient Sample, 2016 to 2018

Data on coronary revascularization in patients with cirrhosis are scarce because it is often deferred in the setting of significant comorbidities and coagulopathies. It is unknown whether patients with cardiac cirrhosis have a worse prognosis. The National Inpatient Sample was surveyed to identify patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for acute coronary syndrome (ACS) from 2016 to 2018. Those with and without liver cirrhosis were propensity score-matched and compared within the PCI and CABG cohorts. Primary outcome was in-hospital mortality. Patients with cirrhosis were further classified into cardiac and noncardiac cirrhosis and their in-hospital mortalities were compared. A total of 1,069,730 PCIs and 273,715 CABGs were performed for ACS, of which 0.6% and 0.7%, respectively, were performed in patients with cirrhosis. In both the PCI cohort (odds ratio = 1.56; 95% confidence interval, 1.10-2.25; P = 0.01) and the CABG cohort (odds ratio = 2.34; 95% confidence interval, 1.19-4.62; P = 0.01), cirrhosis was associated with higher in-hospital mortality. In-hospital mortality was greatest in cardiac cirrhosis (8.4% and 7.1%), followed by noncardiac cirrhosis (5.5% and 5.0%) and no cirrhosis (2.6% and 2.3%) in PCI and CABG cohorts, respectively. Higher in-hospital mortality and periprocedural morbidities should be considered when performing coronary revascularization in patients with cirrhosis.

Part 1: Disease of the Heart and Liver: A Relationship That Cuts Both Ways

The heart and the liver display multifaceted, complex interactions that can be divided into cardiac effects of liver disease, hepatic effects of heart disease, and disease processes affecting both organs. In part 1 of this 2 part series, we discuss how acute and chronic heart failure can have devastating effects on the liver, such as acute cardiogenic liver injury and congestive hepatopathy. On the other hand, primary liver disease, such as cirrhosis, can lead to a plethora of cardiac insults representative in cirrhotic cardiomyopathy as systolic dysfunction, diastolic dysfunction, and electrophysiological disturbances. Nonalcoholic fatty liver disease has long been associated with cardiovascular events that increase mortality. The management of both disease processes changes when the other organ system becomes involved. This consideration is important with regard to a variety of interventions, most notably transplantation of either organ, as risk of complications dramatically rises in the setting of both heart and liver disease (discussed in part 2). As our understanding of the intricate communication between the heart and liver continues to expand so does our management.

Hepatic Encephalopathy-Associated Cerebral Vasculopathy in Acute-on-Chronic Liver Failure: Alterations on Endothelial Factor Release and Influence on Cerebrovascular Function

The acute-on-chronic liver failure (ACLF) is a syndrome characterized by liver decompensation, hepatic encephalopathy (HE) and high mortality. We aimed to determine the mechanisms implicated in the development of HE-associated cerebral vasculopathy in a microsurgical liver cholestasis (MHC) model of ACLF. Microsurgical liver cholestasis was induced by ligating and extracting the common bile duct and four bile ducts. Sham-operated and MHC rats were maintained for eight postoperative weeks Bradykinin-induced vasodilation was greater in middle cerebral arteries from MHC rats. Both Nω-Nitro-L-arginine methyl ester and indomethacin diminished bradykinin-induced vasodilation largely in arteries from MHC rats. Nitrite and prostaglandin (PG) F_1α releases were increased, whereas thromboxane (TX) B₂ was not modified in arteries from MHC. Expressions of endothelial nitric oxide synthase (eNOS), inducible NOS, and cyclooxygenase (COX) 2 were augmented, and neuronal NOS (nNOS), COX-1, PGI₂ synthase, and TXA₂S were unmodified. Phosphorylation was augmented for eNOS and unmodified for nNOS. Altogether, these endothelial alterations might collaborate to increase brain blood flow in HE.

Phosphodiesterases in the Liver as Potential Therapeutic Targets of Cirrhotic Portal Hypertension

Liver cirrhosis is a frequent condition with high impact on patients' life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to morphological remodeling of the organ, a functional dysregulation of the sinusoids, the smallest functional units of liver vasculature, plays a pivotal role. Vascular tone is primarily regulated by the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, wherein soluble guanylate cyclase (sGC) and phosphodiesterase-5 (PDE-5) are key enzymes. Recent data showed characteristic alterations in the expression of these regulatory enzymes or metabolite levels in liver cirrhosis. Additionally, a disturbed zonation of the components of this pathway along the sinusoids was detected. This review describes current knowledge of the pathophysiology of PH with focus on the enzymes regulating cGMP availability, i.e., sGC and PDE-5. The results have primarily been obtained in animal models of liver cirrhosis. However, clinical and histochemical data suggest that the new biochemical model we propose can be applied to human liver cirrhosis. The role of PDE-5 as potential target for medical therapy of PH is discussed.

VALUE OF CLINICAL, LABORATORY PARAMETERS AND ANALYSIS OF RETINAL VASCULARIZATION IN PEDIATRIC PATIENTS WITH PORTAL HYPERTENSION

BACKGROUND

Portal hypertension is one of the complications of cirrhosis and is associated with numerous systemic manifestations, including renal, brain, pulmonary, cardiac and vascular changes. In routine ophthalmological examinations performed at our service, we observed that some children diagnosed with portal hypertension had increased retinal vascular tortuosity.

OBJECTIVE

1. To evaluate the presence of retinal vascular abnormalities (vascular tortuosity) in children diagnosed with portal hypertension; 2. To investigate the association between retinal vascular tortuosity and the presence of gastroesophageal varices in these children; 3. To evaluate the use of clinical and laboratory parameters to predict the presence of gastroesophageal varices in children with portal hypertension.

METHODS

This was a cross-sectional and observational study that included patients aged <18 years with a diagnosis of portal hypertension. The participants included were submitted to dilated fundus examination and fundus photography with Visucam (Carl Zeiss Meditec AG) device. Besides, clinical and laboratorial data were collected from the patients' medical records.

RESULTS

A total of 72 patients were included in this study, and 36% of them had an increase in retinal vascular tortuosity. Platelet count (P=0.001), bilirubin dosage (P=0.013) and aspartate transaminase dosage (AST) (P=0.042) were associated with the presence of gastroesophageal varices in digestive endoscopy. There was no association between retinal vascular tortuosity and the presence of gastroesophageal varices (P=0.498).

CONCLUSION

The results of this study suggest that platelet count, bilirubin dosage, and aspartate transaminase dosage were associated with the presence of gastroesophageal varices in digestive endoscopy. Regarding the retinal findings, we found that there was an increase in retinal vascular tortuosity in 36% of pediatric patients, but no association was found with the presence of gastroesophageal varices.

Association between high dose catecholamine support and liver dysfunction following cardiac surgery

BACKGROUND

Cardiac surgery using cardiopulmonary bypass is a well-established procedure. However, up to 20% to 30% of patients require high dose vasopressor or inotropic support following surgery, enhancing the risk of organ dysfunction and impacting mortality. Nonalcoholic fatty liver disease (NAFLD) is a frequent finding in these patients and may be involved in the pathophysiology of vasoplegia and cardiac failure.

METHODS

Retrospective analysis of 463 patients undergoing elective cardiac surgery in 2014 at our institution. NAFLD was defined using the NAFLD fibrosis score and the vasoactive-inotropy score was used to determine postoperative vasopressor and inotropic dependency.

RESULTS

Patients with NAFLD more often presented with high vasopressor or inotropic support compared to patients without NAFLD, resulting in significant differences after 6 hours (n = 20 [27.0%] of 74 patients), 12 hours (n = 20 [27.0%] of 74 patients), and on the first postoperative day (n = 12 [16.4%] of 73 patients) of intensive care unit (ICU) treatment. Multivariate analysis revealed time of catecholamine application (P = .001), preoperative left ventricular ejection fraction (P = .001), type of surgery (P = .001), model of endstage liver disease on hospital admission (P = .002), pre-existing pulmonary hypertension (P = .004) and NAFLD-time interaction (P = .05) as independent predictors of high vasopressor and inotropic support. Patients with NAFLD had higher degrees of extrahepatic organ dysfunction, were more dependent on hemodialysis, spent more days in the ICU and within the hospital. Patients with NAFLD and high catecholamine support had the highest mortality rates among the study population.

CONCLUSIONS

NAFLD is a common finding in elective cardiac surgery patients. Anesthesiologists and intensivists should be sensitive for the specific risk profile of this population.

Postoperative renal impairment is associated with increased length of stay for incisional hernia repair after liver transplantation

Background

Incisional hernia repair is the most common procedure after orthotopic liver transplantation. Although enhanced recovery protocols are increasingly employed, the post–orthotopic liver transplantation patient may not benefit from all aspects of these models. The aim of the present study is to assess which perioperative interventions and patient factors affect hospital length of stay in a cohort of post–orthotopic liver transplantation patients undergoing incisional hernia repair.

Methods

We conducted a retrospective review of a series of adult patients undergoing incisional hernia repair after orthotopic liver transplantation. The primary endpoint was length of stay. Results were stratified by demographic, intraoperative, and postoperative variables.

Results

Eleven percent (172/1523) of patients who received orthotopic liver transplantation during the study period underwent subsequent incisional hernia repair. Median length of stay was 5 days (range 2–50). The strongest predictor of length of stay was postoperative renal function. Despite liberal intraoperative administration of volume (median 642 mL/h) and brisk intraoperative urine output (median 72 mL/h), postoperative acute kidney injury occurred in 48% of patients. Those that developed acute kidney injury received less intraoperative volume (6 vs 8.5 mL/kg/h; P = .031) and the severity of postoperative renal injury was inversely related to the amount intraoperative volume given.

Conclusions

In patients undergoing incisional hernia repair after orthotopic liver transplantation, postoperative renal function is frequently impaired. Although many aspects of current ERAS protocols may be applied to post-transplant patients, restrictive intraoperative fluid administration strategies should be employed with caution given a high propensity for the development of post-operative acute kidney injury in this complex population.

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Eleven percent (172/1523) of patients who received OLT during the years 2005 to 2016 underwent subsequent IHR.

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The strongest predictor of length of stay in this population was postoperative renal function.

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Despite liberal intraoperative administration of volume (median 642 mL/h; 7 mL/kg/h) and brisk intraoperative urine output (median 72 mL/h), postoperative acute kidney injury (AKI) occurred in 48% of patients.

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Those that developed AKI received less intraoperative volume (6 vs 8.5 mL/kg/h; P = .031) and the severity of postoperative renal injury was inversely related to intraoperative volume

Incidental Coronary Artery Calcification Seen on Low-Dose Computed Tomography Is a Risk Factor for Obstructive Coronary Artery Disease in Patients Undergoing Liver Transplant

Incidental arterial calcification (Ca) on low-dose computed tomography (CT) prior to liver transplant (LT) may help identify those at risk for obstructive coronary artery disease (CAD). A single-center retrospective study of 358 consecutive patients who had undergone LT was performed. Of the 296 patients who met inclusion criteria, 193 patients (65.2%) had CT Ca. Aortic Ca was seen in 116 (39.2%), coronary Ca in 141 (47.6%), and peripheral Ca in 8 patients (2.7%). Patients with coronary Ca were assigned ordinal coronary artery Ca scores and classified as mild, moderate, and severe. All-cause mortality was higher in patients with Ca in any location (14.5% vs 6.8%, P = .05). Of the patients who underwent coronary angiography, those with obstructive CAD were more likely to have aortic and coronary Ca than patients with nonobstructive or no CAD (85.7% vs 50.0%, P = .02 and 92.9% vs 37.9%, P = < .001, respectively). Severe coronary artery Ca scores were more frequent in patients with obstructive CAD (35.7% vs 0%, P < .001). Any severity coronary Ca had an odds ratio of 11.57 (95% CI, 1.61-244.92; P = .04) for obstructive CAD. In conclusion, incidental coronary Ca seen on low-dose CT is a risk factor for obstructive CAD in patients undergoing LT.

Scoring model to predict outcome in critically ill cirrhotic patients with acute respiratory failure: comparison with MELD scoring models and CLIF-SOFA score

BACKGROUND

Critically ill cirrhotic patients have a high mortality, particularly with concomitant respiratory failure on admission. There are no specific models in use for mortality risk assessment in critically ill cirrhotic patients with acute respiratory failure (CICRF). The aim is to develop a risk prediction model specific to CICRF in order to quantify the severity of illness.

METHODS

We analyzed 949 CICRF patients extracted from the MIMIC-III database. The novel model (ARF-CLIF-SOFA) was developed from the CLIF-SOFA score. Cox regression analysis and AUROC were implemented to test the predictive accuracy, compared with existing scores including the CLIF-SOFA score and MELD-related scores.

RESULTS

ARF-CLIF-SOFA contains PaO₂/FiO₂ ratio, lactate, MAP, vasopressor therapy, bilirubin and creatinine (1 point each; score range: 0-6). Based on our patient cohort, the ARF-CLIF-SOFA score had good predictive accuracy for predicting the 30-, 90-day and 1-year mortality (AUROC = 0.767 at 30-day, 0.768 at 90-day, 0.765 at 1-year, respectively). Additionally, the performance of the ARF-CLIF-SOFA is superior to existing scores (all P < 0.001).

CONCLUSION

The ARF-CLIF-SOFA score can be considered a CICRF specific score with a better predictive accuracy compared to the existing scores.

Influence of oxygen content immediately after graft reperfusion on occurrence of postoperative acute kidney injury in living donor liver transplantation

Acute kidney injury (AKI) is a common complication after living donor liver transplantation (LDLT). In this study, we investigated perioperative factors, including oxygen content, related to the postoperative development of AKI after LDLT. The perioperative data of 334 patients were reviewed retrospectively. We identified the postoperative development of AKI based on the Acute Kidney Injury Network criteria. Perioperative variables, including oxygen content, were compared between patients with and without AKI. Potentially significant variables in a univariate analysis were evaluated by multivariate analysis. Postoperative AKI developed in 76 patients (22.7%). Univariate analysis revealed that preoperative factors (body mass index [BMI], diabetes mellitus, C-reactive protein) and intraoperative factors (severe postreperfusion syndrome, packed red blood cell transfusion, furosemide, and oxygen content at the anhepatic phase, 5 minutes and 1 hour after graft reperfusion, and at peritoneal closure) of recipients were significant. The multivariate analysis showed that oxygen content 5 minutes after graft reperfusion, BMI, and furosemide administration were independently associated with postoperative AKI. In conclusion, postoperative AKI was independently associated with oxygen content 5 minutes after graft reperfusion, BMI, and furosemide administration. Meticulous ventilator care and transfusion should be required to maintain sufficient oxygen content immediately after graft reperfusion in patients who undergo LDLT.

Embrionary way to create a fatty liver in portal hypertension

Portal hypertension in the rat by triple partial portal vein ligation produces an array of splanchnic and systemic disorders, including hepatic steatosis. In the current review these alterations are considered components of a systemic inflammatory response that would develop through three overlapping phenotypes: The neurogenic, the immune and the endocrine. These three inflammatory phenotypes could resemble the functions expressed during embryonic development of mammals. In turn, the inflammatory phenotypes would be represented in the embryo by two functional axes, that is, a coelomic-amniotic axis and a trophoblastic yolk-sac or vitelline axis. In this sense, the inflammatory response developed after triple partial portal vein ligation in the rat would integrate both functional embryonic axes on the liver interstitial space of Disse. If so, this fact would favor the successive development of steatosis, steatohepatitis and fibrosis. Firstly, these recapitulated embryonic functions would produce the evolution of liver steatosis. In this way, this fat liver could represent a yolk-sac-like in portal hypertensive rats. After that, the systemic recapitulation of these embryonic functions in experimental prehepatic portal hypertension would consequently induce a gastrulation-like response in which a hepatic wound healing reaction or fibrosis occur. In conclusion, studying the mechanisms involved in embryonic development could provide key results for a better understanding of the nonalcoholic fatty liver disease etiopathogeny.