Effects of contrast media on renal function in patients with cirrhosis: a prospective study

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

A prospective, multicenter, three-cohort study evaluating contrast-induced acute kidney injury (CI-AKI) in patients with cirrhosis

BACKGROUND & AIMS

Nephrotoxicity of intravenous iodinated contrast media (ICM) in cirrhosis is still a debated issue, due to scarce, low-quality and conflicting evidence. This study aims to evaluate the incidence and predisposing factors of acute kidney injury (AKI) in patients with cirrhosis undergoing contrast-enhanced computed tomography (CECT).

METHODS

We performed a prospective, multicenter, cohort study including 444 inpatients, 148 with cirrhosis (cohort 1) and 163 without cirrhosis (cohort 3) undergoing CECT and 133 with cirrhosis (cohort 2) unexposed to ICM. Kidney function parameters were assessed at T0, 48-72 h (T1), 5 and 7 days after CECT/enrollment. Urinary neutrophil gelatinase-associated lipocalin (U-NGAL) was measured in 50 consecutive patients from cohort 1 and 50 from cohort 2 as an early biomarker of tubular damage.

RESULTS

AKI incidence was not significantly increased in patients with cirrhosis undergoing CECT (4.8%, 1.5%, 2.5% in cohorts 1, 2, 3 respectively, p = n.s.). Most AKI cases were mild and transient. The presence of concomitant infections was the only independent predictive factor of contrast-induced AKI (odds ratio 22.18; 95% CI 2.87-171.22; p = 0.003). No significant modifications of U-NGAL between T0 and T1 were detected, neither in cohort 1 nor in cohort 2 (median ΔU-NGAL: +0.2 [-7.6 to +5.5] ng/ml, +0.0 [-6.8 to +9.5] ng/ml, respectively [p = 0.682]).

CONCLUSIONS

AKI risk after CECT in cirrhosis is low and not significantly different from that of the general population or of the cirrhotic population unexposed to ICM. It mostly consists of mild and rapidly resolving episodes of renal dysfunction and it is not associated with tubular kidney injury. Patients with ongoing infections appear to be the only ones at higher risk of AKI.

IMPACT AND IMPLICATIONS

Nephrotoxicity due to intravenous iodinated contrast media (ICM) in patients with cirrhosis is still a debated issue, as the available evidence is limited and based on very heterogeneous studies, often conducted on small and retrospective cohorts. In this prospective three-cohort study we found that intravenous administration of ICM was associated with a low risk of AKI, similar to that of the general population and to that of patients with cirrhosis unexposed to ICM. Patients with ongoing infections were the only ones to have a significantly increased risk of contrast-induced AKI. Therefore, the actual recommendations of performing contrast imaging studies cautiously in cirrhosis do not seem to be reasonable anymore, with the exception of infected patients, who have a significantly higher risk of contrast-induced AKI.

Application of CT contrast medium is not associated with an increased risk for acute kidney injury in patients with decompensated cirrhosis

BACKGROUND

Acute kidney injury (AKI) is a frequent complication in patients with decompensated cirrhosis. Studies reported conflicting results regarding the nephrotoxic potential of iodinated contrast medium (CM) for computer tomography (CT).

AIM

To investigate the impact of diagnostic CM application on kidney function in patients with decompensated cirrhosis.

METHODS

First, we evaluated the impact of diagnostic CM-CT on AKI incidence in a cross-sectional approach. Second, we analysed 28-day AKI incidence post-CM-CT in patients with impaired kidney function (i.e., creatinine >133 μmoL/L). Third, we excluded all patients with relevant interventions besides CM-CT. All remaining patients were matched via propensity score matching (PPSM) and further analysed. Last, we validated the results in an independent dataset of prospectively collected registry data of 118 patients with decompensated cirrhosis. Here, plasma samples were analysed regarding neutrophil-gelatinase-associated-lipocalin (NGAL).

RESULTS

Of the 611 included patients, 98 (16%) received CM-CT. CM-CT was not associated with AKI in the cross-sectional approach (CM-CT:8% vs. no CM-CT:15%; p = 0.08). Furthermore, CM-CT was not associated with higher 28-day AKI incidence among patients with impaired kidney function (HR:0.79; 95% CI 0.45-1.38; p = 0.40). The PPSM cohort revealed no association between CM-CT and AKI or severe AKI (HR:1.28, p = 0.45 and HR:1.62; p = 0.43). Moreover, CM-CT did not result in worsening of kidney function after CM application. In the validation cohort, CM-CT was also not linked to AKI (p = 0.85) and NGAL levels were not increased in those with CM-CT (CM-CT:309 ng/ml vs. No CM-CT:266 ng/ml, p = 0.35).

CONCLUSION

Decompensated cirrhosis per se should not preclude diagnostic CM-CT.

Rate of hepatocellular carcinoma diagnosis in cirrhotic patients with ultrasound-detected liver nodules

Ultrasound (US) detection of liver nodules in cirrhotic patients requires further radiological examinations and often a follow-up with repeated short-term evaluations to verify the presence of hepatocellular carcinoma (HCC). Aims of the study were to assess the rate of HCC diagnosis and to identify HCC predictors in a cohort of cirrhotics followed-up after US detection of the liver nodule(s). One-hundred-eighty-eight consecutive cirrhotic patients (124 males, mean age 64.2 years) with liver nodule(s) detected by US were enrolled. All patients underwent second-level imaging [computed tomography (TC) or magnetic resonance (MR)], and those without a definite diagnosis of HCC were followed-up with TC and/or RM repeated every 3-6 months up to 18 months if HCC was not diagnosed. After 18 months, non-HCC patients came back to routine US surveillance. HCC was diagnosed in 73/188 cases (38.8%). In 66/73 patients (90.4%) HCC was identified at first radiological evaluation after US, while in the remaining seven subjects it was diagnosed at the subsequent imaging examination. Age (p = 0.001) and nodule dimension (p = 0.0001) were independent predictors of HCC at multivariate analysis. Fourty-nine/188 patients were lost at follow up after 18 months. Twenty/139 remaining patients developed HCC and 3/139 cholangiocarcinoma; 77 died between 3 and 110 months from the beginning of the study (61 for end-stage liver disease, 8 for extrahepatic causes, eight for unknown causes). Patients who developed liver cancer earlier during the follow up had the shortest overall survival. US-detected liver nodules are not neoplastic in more than half of cirrhotic patients. A definite diagnosis may be obtained at the time of the first radiologic evaluation after US in the vast majority of the cases. Patients in whom nodules are found not to be tumoral may return to the US surveillance program routinely applied to all cirrhotics.

Global strategy for the diagnosis and management of acute kidney injury in patients with liver cirrhosis

Acute kidney injury (AKI) is a clinical syndrome that complicates the course and worsens clinical outcomes in patients with chronic liver diseases. It is a common complication in hospitalised patients with liver cirrhosis, especially those with decompensated cirrhosis, associated with a high mortality rate. Considering its impact on patient prognosis, efforts should be made to diagnose and tailor therapeutic interventions for AKI at an early stage. In the past decade, a significant progress has been made to understand the key events and define major prognostic factors for the onset and progression of AKI in the cirrhotic population leading hepatologists to redefine the classic definition of hepatorenal syndrome and renal failure in this specific population.

Efficacy of CTPV for Diagnostic and Therapeutic Assessment: Comparison with Endoscopy in Cirrhotic Patients with Gastroesophageal Varices

Background and Aims

Computed tomography portal venography (CTPV) shows potential in detecting varices that need treatment and their drainage pathways. However, its agreement with endoscopy requires further study. We investigated the feasibility of CTPV as an alternative tool to endoscopy in screening gastroesophageal varices (GEVs) and developed a CTPV-based model to provide a less invasive assessment of endotherapy for cirrhotic patients with GEVs.

Methods

The study included 33 cirrhotic patients with a recent history of variceal hemorrhage. The presence, grade, and classification of GEVs on endoscopy and CTPV were compared (kappa test). Twenty-four patients were treated endoscopically, including 12 for esophageal varices (EVs), 8 for gastric varices (GVs), and 4 for GEVs. Treatment efficacies were assessed with the newly developed CTPV-based method at 1 week and 1 month after treatment. Efficiency evaluated by CTPV and endoscopy was compared by Fisher's exact test to determine whether CTPV is efficient in the assessment of endotherapy efficacy.

Results

For the screening and grading/classification of EVs and GVs, substantial agreement (EV kappa: 0.63 and 0.68; GV kappa: 0.62 and 0.75, respectively) was noted between endoscopy and CTPV. The therapeutic efficacy of EVs was higher when assessed by CTPV than when evaluated by endoscopy (37.50% vs. 12.50% at 1 week postoperation, P = 0.22; 62.50% vs. 25.00% at 1 month postoperation, P = 0.07), but without statistical significance. The same trend was also found in the assessment of therapeutic efficacy for GVs (25.00% vs. 16.67% at 1 week postoperation, P = 1; 58.33% vs. 41.67% at 1 month postoperation, P = 0.68).

Conclusion

CTPV is comparable to endoscopy in the detection of GEVs and in the evaluation of endotherapy efficacy, which suggests that it could be a less invasive alternative for endoscopy in cirrhotic patients with GEVs needing treatment.

Contrast-induced acute kidney injury following coronary angiography in patients with end-stage liver disease

Background: Contrast-induced acute kidney injury (CIAKI) following coronary angiography is frequently observed in the general population. End-stage liver disease (ESLD) patients are at a particularly increased risk for development of CIAKI following coronary angiography due to preexisting renal hypoperfusion.

Methods: We performed a retrospective study of 544 consecutive cardiac catheterizations in ESLD patients from December 2003 to May 2013 to calculate the incidence of CIAKI post-coronary angiography and to identify risk factors for CIAKI. CIAKI was defined as a serum creatinine increase of either ≥ 25% or ≥ 0.5 mg/dL from baseline within 72 hours. Multivariable and Cox regression analysis was performed for development of CIAKI and all-cause mortality, respectively.

Results: Overall, 179 cases of coronary angiography were included in the final analysis. CIAKI occurred in 23% of patients. All-cause mortality was 52% in the CIAKI group and 37% in the non-CIAKI group, with a mean follow-up of 2.2 ± 3.8 years. Multivariable analysis identified intensive care unit admission (OR 2.72, CI 1.05–7.01, p < 0.05) and baseline estimated glomerular filtration rate (OR 1.02, CI 1.002–1.035, p < 0.05) as independent predictors of CIAKI. Cox regression analysis identified pre-angiography beta-blocker use (HR 2.13, CI 1.04–4.38, p < 0.05), international normalized ratio (HR 1.37, CI 1.05–1.78, p < 0.05) and Mehran risk score (HR 1.13, CI 1.02–1.25, p < 0.05) as independent predictors of all-cause mortality.

Conclusions: CIAKI in ESLD patients undergoing coronary angiography occurs at a moderately elevated rate when compared to the general population.

Current approaches to the management of patients with cirrhotic ascites

This review describes current approaches to the management of patients with cirrhotic ascites in relation to the severity of its clinical manifestations. The PubMed database, the Google Scholar retrieval system, the Cochrane Database of Systematic Reviews, and the reference lists from related articles were used to search for relevant publications. Articles corresponding to the aim of the review were selected for 1991-2018 using the keywords: "liver cirrhosis," "portal hypertension," "ascites," "pathogenesis," "diagnostics," and "treatment." Uncomplicated and refractory ascites in patients with cirrhosis were the inclusion criteria. The literature analysis has shown that despite the achievements of modern hepatology, the presence of ascites is associated with poor prognosis and high mortality. The key to successful management of patients with ascites may be the stratification of the risk of an adverse outcome and personalized therapy. Pathogenetically based approach to the choice of pharmacotherapy and optimization of minimally invasive methods of treatment may improve the quality of life and increase the survival rate of this category of patients.

Chinese guidelines on the management of ascites and its related complications in cirrhosis

The Chinese Society of Hepatology developed the current guidelines for the Management of Ascites and Its Related Complications in Cirrhosis based on the published evidences and the panelists' consensus. The guidelines provided recommendations for the diagnosis and management of cirrhotic ascites emphasizing a step-wise approach with the first-, second-, and third-line therapy. For refractory ascites, vasoconstrictors and albumin are recommended for splanchnic vasodilation and selective vasopressin (V2) receptor antagonists for moderate-to-severe hyponatremia. For spontaneous bacterial peritonitis, empirical anti-infection treatment was recommended based on the local microbiological examination of community- or hospital-acquired infections. For hepatorenal syndrome, the administration of vasopressor terlipressin and albumin is recommended.

Acute kidney injury in cirrhotic patients undergoing contrast-enhanced computed tomography

Contrast medium administration is one of the leading causes of acute kidney injury (AKI) in different clinical settings. The aim of the study was to investigate occurrence and predisposing factors of AKI in cirrhotic patients undergoing contrast-enhanced computed tomography (CECT).Datasets of 1279 consecutively hospitalized cirrhotic patients were retrospectively analyzed. Two hundred forty-nine of 1279 patients (mean age 64 ± 11 years, 165 male) who had undergone CECT were selected on the basis of the availability of serum creatinine (sCr) values evaluated before and after CECT (CECT group). In analogy, 203/1279 cases (mean age 66 ± 10 years, 132 male) who had not undergone CECT and had been tested twice for sCr in 7 days were also included as controls (Control group). AKI network criteria were employed to assess contrast-induced AKI (CI-AKI) development. Apart from lack of narrowed double sCr measurements, additional exclusion criteria were active bacterial infections, nephrotoxic drugs intake, and estimated glomerular filtration rate <30 mL/min.AKI developed in 22/249 (8.8%) and in 6/203 (3%) of the CECT and the Control groups, respectively (P = 0.01). The multivariate logistic regression analysis showed that AKI was significantly associated with contrast medium administration (odds ratio [OR]: 3.242, 95% confidence interval [CI]: 1.255-8.375; P = 0.015), female sex (OR: 0.339, 95% CI: 0.139-0.827; P = 0.017), and sCr values (OR: 0.124, 95% CI: 0.016-0.975; P = 0.047). In the CECT group, presence of ascites (OR: 2.796, 95% CI: 1.109-7.052; P = 0.029), female sex (OR: 0.192, 95% CI: 0.073-0.510; P = 0.001), and hyperazotemia (OR: 1.018, 95% CI: 1.001-1.037; P = 0.043) correlated with CI-AKI development at multivariate analysis.CI-AKI is a quite frequent occurrence in cirrhotic patients with female sex, presence of ascites, and hyperazotemia being the predisposing factors.

Contrast-induced acute kidney injury in cirrhotic patients. A retrospective analysis

BACKGROUND

The nephrotoxic potential of intravenous iodinated contrast (IC) is controversial. Cirrhotic patients are often submitted to imaging procedures involving IC and small changes in renal function may have detrimental effects.

MATERIAL AND METHODS

Retrospective analysis of hospitalized patients with elective imaging by either contrast-enhanced CT or MRI. Contrast induced acute kidney injury (CI-AKI) was diagnosed if there was either an increase of SCr by 25% or by 44 μmol/L or a decrease of estimated glomerular filtration rate by 25% by day 3.

RESULTS

Between 2004 and 2012 152 patients (female: 30.3%, age: 60 ± 10.8 years, MELD 13 ± 6) were included in this study of which 84 (55.3%) had received IC and 68 (44,7%), who served as controls, MRI with gadolinium based contrast (non-IC). Baseline parameters were well matched except for age (61.7 vs. 56.9) years in the IC vs. non-IC groups, p = 0.005). 15 patients (17.9%) receiving IC and 4 patients (5.9%) not receiving IC (p = 0.026) reached the composite end-point for CI-AKI. In multivariable regression analysis INR [B = 0.252 (95% CI: 0.108-0.397), p = 0.001]; IC [B = 0.136 (95% CI: 0.023-0.248), p = 0.019] and serum sodium [B = 0.011 (95% CI: 0.001-0.023); p = 0.080] were independently associated with changes of SCr. In conclusion IC may cause renal dysfunction in cirrhotic patients. Patients subjected to imaging using IC should be closely monitored.

The incidence of contrast-induced nephropathy (CIN) following transarterial chemoembolisation (TACE) in patients with hepatocellular carcinoma (HCC)

PURPOSE

The purpose of this retrospective study was to investigate the incidence of contrast-induced nephropathy (CIN) caused by transarterial chemoembolisation (TACE) in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

One hundred forty-one patients treated between 2005 and 2008 undergoing 305 consecutive sessions of TACE were enrolled. CIN was defined as an increase in the serum creatinine level of more than 0.5 mg/dl or more than 25 % from baseline within 3 days after TACE without any other identifiable cause of acute kidney injury.

RESULTS

CIN by the present definition was observed after 2.6 % of the TACE sessions. No patient showed clinical signs or symptoms of acute renal failure, or required haemodialysis. None of the patients with an estimated glomerular filtration rate of <60 ml/min/1.73 m(2) developed CIN.

CONCLUSION

The present study suggests that TACE is a relatively safe procedure in terms of the risk of CIN under vigorous periprocedural hydration and that the incidence of CIN is comparable to that of AKI associated with intravenous CM administration.

KEY POINTS

• CIN would be lower for non-coronary arterial intervention than for coronary intervention. • The present study suggests that the CIN rates following TACE are low. • The incidence of CIN is comparable to that after intravenous CM administration.

Updates on Hepato-Renal Syndrome

Hepato-renal syndrome (HRS) is one of the most detrimental conditions in patients with end stage liver failure. Historically, HRS was considered a terminal disease associated with cirrhosis and was termed "liver-death syndrome". Furthermore, despite the improved understanding of pathophysiology and the reversibility of renal dysfunction in HRS, mortality remains extremely high especially for type 1 HRS. This review summarizes the recent advances in the pathophysiology, diagnosis and management of HRS and also provides an evolving area of research in the pathophysiologic mechanisms of HRS, which may open the door for new therapeutic approaches.

Intravenous albumin for the prevention of contrast-induced nephropathy in patients with liver cirrhosis and chronic kidney disease undergoing contrast-enhanced CT

BACKGROUND

The purpose of this study was to evaluate the incidence of contrast-induced nephropathy (CIN), and the effect of intravenous albumin for prophylaxis of CIN in patients with liver cirrhosis (LC) and chronic kidney disease (CKD).

METHODS

We conducted a retrospective study of 81 subjects with LC and CKD (estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m(2)) who underwent contrast-enhanced computed tomography (CT). Patients received either isotonic sodium bicarbonate solution (3 mL/kg for 1 h before CT and 1 mL/kg/h for 6 h after CT) or albumin (20% albumin, 25 mL for 1 h before CT and 75 mL for 6 h after CT). CIN was defined as an increase of ≥25% or ≥0.5 mg/dL in serum creatinine level.

RESULTS

Overall, CIN developed in three patients (3.7%). Of the 81 subjects, 43 received sodium bicarbonate solution and 38 received albumin. Both groups were comparable with regard to age, sex, diabetes mellitus, and baseline eGFR. The albumin group showed a significantly poorer liver function profile. CIN incidence did not differ significantly between the groups: it occurred in one (2.3%) of the 43 subjects receiving sodium bicarbonate and two (5.3%) of the 38 subjects receiving albumin (P=0.6). However, the albumin group showed a significantly smaller increase in body weight (P=0.03).

CONCLUSION

The incidence of CIN in patients with LC and CKD undergoing contrast-enhanced CT after preventive measures was relatively low. The incidence of CIN was not significantly different between sodium bicarbonate and albumin groups.

Medical management of hepatorenal syndrome

Hepatorenal syndrome (HRS) is defined as the occurrence of renal dysfunction in a patient with end-stage liver cirrhosis in the absence of another identifiable cause of renal failure. The prognosis of HRS remains poor, with a median survival without liver transplantation of <6 months. However, understanding the pathogenesis of HRS has led to the introduction of treatments designed to increase renal perfusion and mean arterial blood pressure using vasopressors and albumin, which has led to improvement in renal function in ∼50% of patients.

Hepatorenal syndrome

INTRODUCTION

Renal failure in cirrhosis is a common complication that is associated with poor survival. A rapid diagnosis of the cause of renal failure is mandatory because it is associated with prognosis.

AREAS COVERED

This review covers the differential diagnosis between hepatorenal syndrome (HRS) and other causes of renal failure, as well as the difficulty in making a correct diagnosis, caused by the differentiation between hepatorenal syndrome and acute tubular necrosis. This review also discusses the multifactorial mechanisms involved in the pathogenesis of HRS. The paper provides diagnostic algorithms to use in clinical practice, emphasized by the fact that some patients may have HRS superimposed on pre-existent renal failure.

EXPERT OPINION

The correct diagnosis of renal failure is essential to initiate the correct treatment of this complication. In patients with HRS type 1, treatment with vasopressin and albumin is the treatment of choice; however, 50% of patients do not respond to this treatment.

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.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Contrast-induced nephropathy after intravenous administration: fact or fiction?

Recent prospective clinical investigations in high-risk patients receiving intravenous contrast media for computed tomography (CT) suggest that the incidence and serious negative clinical outcomes are much less common than previously believed. Additional perspectives comparing random variations in serum creatinine in subjects not receiving contrast media show similar fluctuations that would equate to contrast-induced nephrotoxicity (CIN). Putative mechanisms for how CIN could cause death or other serious adverse clinical consequences have not been elucidated.

Risk of contrast-induced nephropathy in hospitalized patients with cirrhosis

AIM: To evaluate the incidence of contrast-induced nephropathy (CIN) in cirrhotic patients and to identify risk factors for the development of CIN.

METHODS: We performed a retrospective review of 216 consecutive patients with cirrhosis who underwent computed tomography (CT) with intravenous contrast at the University of Rochester between the years 2000-2005. We retrospectively examined factors associated with a high risk for CIN, defined as a decrease in creatinine clearance of 25% or greater within one week after receiving contrast.

RESULTS: Twenty-five percent of our patients developed CIN, and 74% of these patients had ascites seen on CT. Of the 75% of patients who did not develop CIN, only 46% had ascites. The presence of ascites was a significant risk factor for the development of CIN (P = 0.0009, OR 3.38, 95% CI 1.55-7.34) in multivariate analysis. Patient age, serum sodium, Model for End-stage Liver Disease score, diuretic use, and the presence of diabetes were not found to be significant risk factors for the development of CIN. Of the patients who developed CIN, 11% developed chronic renal insufficiency, defined as a creatinine clearance less than baseline for 6 wk.

CONCLUSION: Our results suggest that in hospitalized cirrhotic patients, especially those with ascites, the risk of CIN is substantial.

TACE versus TAE as therapy for hepatocellular carcinoma

Transarterial chemoembolization (TACE) improves survival in cirrhotic patients with hepatocellular carcinoma (HCC). The optimal schedule, best anticancer agent and best technique are still unclear. TACE may not be better than transarterial embolization (TAE). HCC is very chemoresistant, thus embolization may be more important than chemotherapy. Lipiodol cannot be considered as an embolic agent and there are no data to show that it can release chemotherapeutic agents slowly. It can mask residual vascularity on CT imaging and its use is not recommended. Both TACE and TAE result in hypoxia, which stimulates angiogenesis, promoting tumor growth; thus combination of TACE with antiangiogenic agents may improve current results. To date, there is no evidence that TACE pre-liver transplantation or resection helps to expand current selection criteria for patients with HCC, nor results in less recurrence after surgery. Combination with other techniques, such as radiofrequency ablation and drugs, may enhance the effect of TACE. New trials are being conducted to clarify these issues.

Evidence-based diagnosis and locoregional therapy for hepatocellular carcinoma

Early identification of hepatocellular carcinoma (HCC) is crucial to improving the results of therapy and for patients to be eligible for liver transplantation. Recent advances in noninvasive imaging technology include various techniques of harmonic ultrasound, new ultrasound contrast agents, multislice helical computed tomography and rapid high-quality magnetic resonance. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. Since the use of better radiological techniques has improved the accuracy of noninvasive diagnosis, the role of liver biopsy in the diagnosis of HCC has declined. With recent advances in genomics and proteomics, a great number of potential markers have been identified and developed as new candidate markers for HCC. Locoregional therapies currently constitute the best options for early nonsurgical treatment of HCC. Percutaneous ethanol injection shows similar results to resection surgery for single tumors less than 3 cm in diameter. Radiofrequency ablation is superior to percutaneous ethanol injection in terms of local recurrence. Transarterial chemoembolization is currently the most common approach for the management of HCC without curative options since it improves patient survival, but the optimal embolizing agent, length of interval between sessions and whether the chemotherapeutic agent has any effect have not yet been determined. Combining transarterial chemoembolization with antiangiogenic agents, as well as with other techniques, such as radiofrequency ablation, may improve the results. Injection of radioisotopes such as yttrium-90, via the hepatic artery, may be particularly useful in patients with portal vein thrombosis. Comparisons with other transarterial techniques are needed.

The hepatorenal syndrome

The onset of renal failure in a patient with cirrhosis or acute liver failure is alarming because it raises the possibility of the hepatorenal syndrome (HRS). Periodic surveillance of renal function is helpful in patients with severe liver disease to detect HRS early and to help correct reversible contributing factors. Once established, HRS responds relatively poorly to medical management, although recent advances have brought hope for an improved prognosis. In this article the diagnosis, pathophysiology, and management of HRS are discussed in detail, with an emphasis on recent diagnostic and therapeutic advances.

Acute renal dysfunction in liver diseases

Renal dysfunction is common in liver diseases, either as part of multiorgan involvement in acute illness or secondary to advanced liver disease. The presence of renal impairment in both groups is a poor prognostic indicator. Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction. Obstructive or post renal dysfunction only rarely complicates liver disease. Hepatorenal syndrome (HRS) is a unique form of renal failure associated with advanced liver disease or cirrhosis, and is characterized by functional renal impairment without significant changes in renal histology. Irrespective of the type of renal failure, renal hypoperfusion is the central pathogenetic mechanism, due either to reduced perfusion pressure or increased renal vascular resistance. Volume expansion, avoidance of precipitating factors and treatment of underlying liver disease constitute the mainstay of therapy to prevent and reverse renal impairment. Splanchnic vasoconstrictor agents, such as terlipressin, along with volume expansion, and early placement of transjugular intrahepatic portosystemic shunt (TIPS) may be effective in improving renal function in HRS. Continuous renal replacement therapy (CRRT) and molecular absorbent recirculating system (MARS) in selected patients may be life saving while awaiting liver transplantation.

Hemodynamic evaluation before liver transplantation: insights into the portal hypertensive syndrome

The cardiac hemodynamics of patients awaiting liver transplantation is complex. Coronary atherosclerosis, a hyperdynamic circulatory state and cirrhotic cardiomyopathy are present to a variable degree in this population. In this contribution to the Symposium on Portal Hypertension, we expand on our published experience with coronary angiography and cardiac hemodynamics at the time of evaluation of candidacy for liver transplantation in a cohort of 161 patients. Although we confirmed the relation of systemic hemodynamics with the degree of liver failure, we noted a higher prevalence of high output heart failure, defined as an increased left ventricular end-diastolic pressure in the setting of an elevated cardiac output, most notably in patients classified as Child C. Most patients with high pulmonary artery pressure also exhibited evidence of elevated left ventricle filling pressures. A low systemic vascular resistance, a marker of arterial vasodilatation, was similar in the presence of atherosclerosis, a condition where impaired vasorelaxation occurs as a result of endothelial dysfunction. The high prevalence of coronary artery disease in this series supports the observations that atherosclerosis is a major issue in the current population with cirrhosis awaiting liver transplantation. A lower sensitivity of noninvasive screening tools for the detection of coronary atherosclerosis is likely the result of the interaction of the hyperdynamic circulation with the performance of these tests.

Conflicting and new risk factors for contrast induced nephropathy

PURPOSE

Iodinated contrast medium is commonly used in diagnostic or interventional procedures in uroradiology. Procedures requiring the intravascular administration of iodinated contrast medium are becoming a great source of an iatrogenic disease known as contrast induced nephropathy. Identifying patients at high risk is the first step to minimize the overall risk of contrast induced nephropathy. This review describes conflicting and new risk factors for contrast induced nephropathy.

MATERIALS AND METHODS

A MEDLINE/PubMed search from 1966 to 2006 was performed. All articles related to the use of contrast medium and the risk factors for contrast induced nephropathy were reviewed.

RESULTS

The classic risk factors for contrast induced nephropathy are preexisting renal failure, diabetes mellitus, advanced age, nephrotoxic agent administration, hypovolemia, use of a large amount of contrast medium or an ionic hyperosmolar contrast medium and congestive heart failure. Metabolic syndrome, prediabetes and hyperuricemia have been identified as new risk factors for contrast induced nephropathy. The use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, renal transplantation, diabetes mellitus with normal renal function, low osmolar contrast medium in patients at high risk for contrast induced nephropathy, multiple myeloma, female gender and cirrhosis have been classified as conflicting risk factors for contrast induced nephropathy.

CONCLUSIONS

Patients at risk for contrast induced nephropathy should be identified before urological procedures requiring contrast administration. In addition to the classic risk factors for contrast induced nephropathy, determining the metabolic syndrome, hyperuricemia and prediabetes as well as the use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers before performing procedures using contrast medium seems to be a useful guide to assess the risk of contrast induced nephropathy.

Repeated courses of transarterial embolization with polyvinyl alcohol particles: 'long life elixir' in a cirrhotic patient with unresectable hepatocellular carcinoma

Chemoembolization improves survival in selected cirrhotic patients with hepatocellular carcinoma, but prolonged survival is unusual. In this study, a 70-year-old cirrhotic patient, who had a histologically proven hepatocellular carcinoma of 5 cm diameter, embolization with polyvinyl alcohol particles alone, without chemotherapeutic agent, has resulted in continued survival, of 5 years to date, with virtual elimination of residual hypervascularity following 10 sessions of embolization, and with continued patency of the injected branch of the hepatic artery. Provided liver function is maintained, embolization alone appears a feasible long term and effective therapy for unresectable hepatocellular carcinoma.

Transarterial therapy for hepatocellular carcinoma: which technique is more effective? A systematic review of cohort and randomized studies

BACKGROUND

Chemoembolization (TACE) improves survival in cirrhotic patients with hepatocellular carcinoma (HCC). The optimal schedule, or whether embolization (TAE) alone gives the same survival advantage, is not known.

PURPOSE

To evaluate whether specific patient characteristics and/or radiological transarterial techniques result in better outcomes.

METHOD

A PubMed search was carried out for cohort and randomized trials (n = 175) testing transarterial therapies; meta-analysis was performed where appropriate.

RESULTS

Anticancer drugs were used as sole agent in 75% of cases (double 15% and triple 6%): doxorubicin (36%), cisplatin (31%), epirubicin (12%), mitoxantrone (8%), mitomycin (8%), and SMANCS (5%). Embolizing agents used were: gelatin sponge particles (71%), polyvinyl alcohol (PVA) particles (8%), degradable starch microspheres (DSM) (4%), and embospheres (4%). Sessions per patient were 2.5 +/- 1.5 (interval: 2 months). Objective response was 40 +/- 20%; survival rates at 1, 2, 3, and 5 years were: 62 +/- 20%, 42 +/- 17%, 30 +/- 15%, and 19 +/- 16%, respectively, and survival time was 18 +/- 9.5 months. The post-TACE complications were: acute liver failure, 7.5% (range 0-49%); acute renal failure, 1.8% (0-13%); encephalopathy, 1.8% (0-16%); ascites, 8.3% (0-52%); upper gastrointestinal bleeding; 3% (0-22%); and hepatic or splenic abscess, 1.3% (0-2.5%). Treatment-related mortality was 2.4% (0-9.5%), mainly due to acute liver failure. Our meta-analysis of nine randomized controlled trials (RCTs) confirmed that TACE improves survival; but a meta-analysis of TACE versus TAE alone (3 RCTs, 412 patients) demonstrated no survival difference.

CONCLUSIONS

No chemotherapeutic agent appears better than any other. There is no evidence for benefit with lipiodol. Gelatin sponge is the most used embolic agent, but PVA particles may be better. TAE appears as effective as TACE. New strategies to reduce the risk of post-TACE complications are required.

High-risk situations and procedures

With the wider use of imaging and interventional techniques that require the use of iodinated contrast media in seriously ill patients, many clinical situations occur where patients may be at increased risk for contrast-induced nephropathy (CIN). There is little guidance for clinicians in these areas. The aim of this review is to assess the available literature. Acute renal failure is a common complication following coronary artery bypass surgery, and exposure to contrast medium may increase the risk for this condition, although there is insufficient evidence to make a definitive statement. Evidence is also limited for patients with liver disease: in those undergoing transarterial chemoembolization, cirrhosis may be a risk factor for renal failure. There is some evidence that periprocedural hypotension may be a risk factor for CIN after percutaneous coronary intervention, but no published information was identified on the significance of shock or hypotension in other groups of patients. The published evidence on the risk of CIN in renal transplant recipients is inconsistent. In emergency situations, the course of action is usually dictated by clinical circumstances; the renal status of a patient is likely to be unknown and it is important to ensure adequate volume expansion, especially after the procedure. In all clinical situations that are potentially associated with a high risk for CIN, the decision to administer contrast medium is a matter for clinical judgment, based on the clinical status of the patient and the expected benefits of the investigation or procedure.

Risk prediction of contrast-induced nephropathy

In order to make appropriate decisions about clinical management, it is important for physicians to be able to stratify patients according to their risk for contrast-induced nephropathy (CIN). The most important risk marker for nephropathy after exposure to iodinated contrast media is preexisting renal impairment. The risk of CIN is elevated and becomes clinically important in patients with chronic kidney disease characterized by an estimated glomerular filtration rate <60 mL/min per 1.73 m(2). In patients with renal impairment, diabetes mellitus amplifies the risk of CIN and complicates postprocedure management. Other markers associated with an increased risk of CIN include cardiovascular disease, periprocedural hemodynamic instability, use of nephrotoxic drugs, and anemia. The effect of risk factors is additive, and the presence of multiple risk factors in the same patient can create a very high risk for CIN and acute renal failure requiring dialysis. Risk models incorporating baseline and periprocedural characteristics have been developed using data from large databases of percutaneous coronary intervention patients. These schemes are potentially valuable, but at present the most practical approach to risk prediction is based on a simple model incorporating renal function and diabetes mellitus.

Therapy insight: Management of hepatorenal syndrome

Hepatorenal syndrome (HRS), a feared complication of advanced cirrhosis, is characterized by functional renal failure, secondary to renal vasoconstriction in the absence of underlying kidney pathology. Extreme underfilling of the arterial circulation, caused by arterial vasodilation of the splanchnic circulation, activates vasoconstrictor systems, which lead to intense renal vasoconstriction and HRS. Factors predictive for the development of HRS include intense urinary sodium retention, dilutional hyponatremia, low blood pressure, decreased cardiac output, and increased activity of systemic vasoconstrictors. The prognosis for patients with HRS is extremely poor, especially for those with the acute, progressive (type 1) form. Liver transplantation is the best treatment for suitable candidates and should always be the management option considered first. Pharmacologic therapies are aimed at improving renal function to enable patients to survive until transplantation is possible. These therapies are based on plasma expansion with albumin, combined with the use of either vasopressin analogs or alpha-adrenergic agonists. Other nonpharmacologic therapies, such as transjugular intrahepatic portosystemic shunts and albumin dialysis show promise, but experience with these treatments is limited. For prevention of HRS, albumin infusion is recommended in patients with spontaneous bacterial peritonitis, and pentoxifylline treatment is recommended in patients with acute alcoholic hepatitis.

Hepatorenal syndrome

Among the many causes of renal failure in patients who have advanced liver disease, functional renal failure occurring in the absence of parenchymal kidney disease, better known as hepatorenal syndrome (HRS), is the most frequent cause of renal dysfunction in patients who have cirrhosis. This article focuses on the pathogenesis, clinical features, diagnostic approach, and current treatment of HRS in cirrhosis.

Renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis: value of MELD score

BACKGROUND & AIMS

Although renal failure is a common complication of sepsis and patients with cirrhosis frequently develop sepsis, there have been no studies specifically assessing renal function in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis. The aim of this study was to investigate prospectively the frequency, characteristics, and outcome of renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis.

METHODS

One hundred six consecutive patients with cirrhosis and sepsis were studied prospectively. Patients with spontaneous bacterial peritonitis were excluded.

RESULTS

Twenty-nine out of 106 patients (27%) with cirrhosis and sepsis developed acute renal failure as compared with only 8 of 100 patients (8%) from a control group of cirrhotic patients without infection (P < .0001). Renal failure in the sepsis group was reversible in 22 (76%; 21% of all patients) patients and nonreversible in 7 (24%; 6% of all patients) patients. Renal failure was associated with impairment of effective arterial blood volume, without evidence of tubular damage. The occurrence and type of renal failure correlated strongly with mortality (mortality at 3 months: nonreversible renal failure, 100%; reversible renal failure, 55%; no renal failure, 13%). Among variables obtained at diagnosis of sepsis, the Model for End-Stage Liver Disease (MELD) score was the only independent predictive factor of mortality.

CONCLUSIONS

Renal failure is common in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis and is associated with arterial underfilling and renal vasoconstriction. Outcome is poor, even in the setting of reversible renal failure. The MELD score is the best prognostic marker of patients with cirrhosis and sepsis.

Portal hypertension

PURPOSE OF REVIEW

Report on significant advances in the pathophysiology, diagnosis, and management of the complications of portal hypertension that have occurred in the last year.

RECENT FINDINGS

The specific areas reviewed refer to experimental studies aimed at modifying the factors that lead to portal hypertension (increased intrahepatic vascular resistance and splanchnic vasodilatation) and recent advances in the diagnosis and management of the complications of portal hypertension. The specific complications reviewed in this paper are varices and variceal bleeding (primary prophylaxis, treatment of the acute episode, and secondary prophylaxis), ascites and some of its complications (hyponatremia, hepatic hydrothorax), hepatorenal syndrome, spontaneous bacterial peritonitis, and hepatic encephalopathy.

SUMMARY

Important studies, mostly prospective, regarding the management of the complications of portal hypertension are reviewed, including trials that demonstrate the value of the hepatic venous pressure gradient in predicting these complications, a trial of beta-blockers in patients with small varices, a randomized trial of transjugular intrahepatic portosystemic shunt using covered stents and another pilot study using this shunt in the treatment of hepatorenal syndrome, a trial of antibiotic prophylaxis in preventing early variceal rebleeding, and a trial of synbiotic therapy in hepatic encephalopathy. These trials will contribute to advancing the practice of hepatology and defining future research areas.

Effects of contrast media on renal function in patients with cirrhosis: a prospective study

Patients with cirrhosis are frequently submitted to radiological procedures that require the administration of contrast media. Contrast media is a well-known cause of renal failure, particularly in the presence of some predisposing conditions. However, it is not known whether cirrhosis constitutes a risk factor for contrast media-induced renal failure. The aim of this study was to assess the possible nephrotoxicity of contrast media in patients with cirrhosis. In a first protocol, renal function was evaluated with sensitive methods (glomerular filtration rate using iothalamate I 125 clearance and renal plasma flow using iodohippurate I 131 clearance) before and 48 hours after the administration of contrast media in 31 patients with cirrhosis (20 with ascites, 5 with renal failure). Solute-free water clearance, urine sodium, prostaglandins, and markers of tubular damage were also measured. The administration of contrast media was not associated with significant changes in renal function tests, neither in the whole group of patients nor in patients with ascites or renal failure. Urinary prostaglandin E2 and N-acetyl-beta-D-glucosaminidase increased significantly, but sodium and solute-free water excretion remained unchanged. In a second protocol, a different series of 60 patients with cirrhosis and renal failure were examined prospectively. No patient had renal failure due to contrast media. Only in 1 patient with septic shock was contrast media a possible contributing factor. In conclusion, the administration of contrast media is not associated with adverse effects on renal function in patients with cirrhosis. Cirrhosis does not appear to be a risk factor for the development of contrast media-induced nephrotoxicity.