Pre‐liver transplant renal dysfunction and association with post‐transplant end‐stage renal disease: A single‐center examination of updated UNOS recommendations

[Hepatorenal Syndrome]

Hepatorenal syndrome (HRS) is a critical and potentially life-threatening complication of advanced liver disease, including cirrhosis. It is characterized by the development of renal dysfunction in the absence of underlying structural kidney pathology. The pathophysiology of HRS involves complex interactions between systemic and renal hemodynamics, neurohormonal imbalances, and the intricate role of vasoconstrictor substances. Understanding these mechanisms is crucial for the timely identification and management of HRS. The diagnosis of HRS is primarily clinical and relies on specific criteria that consider the exclusion of other causes of renal dysfunction. The management of HRS comprises two main approaches: vasoconstrictor therapy and albumin infusion, which aim to improve renal perfusion and mitigate the hyperdynamic circulation often seen in advanced liver disease. Additionally, strategies such as liver transplantation and renal replacement therapy are essential considerations based on individual patient characteristics and disease severity. This review article provides a comprehensive overview of hepatorenal syndrome, focusing on its pathophysiology, diagnostic criteria, and current management strategies.

[Anesthesia for organ transplant patients]

Organ transplant patients who must undergo nontransplant surgical interventions can be challenging for the anesthesiologists in charge. On the one hand, it is important to carefully monitor the graft function in the perioperative period with respect to the occurrence of a possible rejection reaction. On the other hand, the ongoing immunosuppression may have to be adapted to the perioperative requirements in terms of the active substance and the route of administration, the resulting increased risk of infection and possible side effects (e.g., myelosuppression, nephrotoxicity and impairment of wound healing) must be included in the perioperative treatment concept. Furthermore, possible persistent comorbidities of the underlying disease and physiological peculiarities as a result of the organ transplantation must be taken into account. Support can be obtained from the expertise of the respective transplantation center.

Hepatorenal syndrome: Current concepts and future perspectives

Hepatorenal syndrome (HRS), a progressive but potentially reversible deterioration of kidney function, remains a major complication in patients with advanced cirrhosis, often leading to death before liver transplantation (LT). Recent updates in the pathophysiology, definition, and classification of HRS have led to a complete revision of the nomenclature and diagnostic criteria for HRS type 1, which was renamed HRS-acute kidney injury (AKI). HRS is characterized by severe impairment of kidney function due to increased splanchnic blood flow, activation of several vasoconstriction factors, severe vasoconstriction of the renal arteries in the absence of kidney histologic abnormalities, nitric oxide dysfunction, and systemic inflammation. Diagnosis of HRS remains a challenge because of the lack of specific diagnostic biomarkers that accurately distinguishes structural from functional AKI, and mainly involves the differential diagnosis from other forms of AKI, particularly acute tubular necrosis. The optimal treatment of HRS is LT. While awaiting LT, treatment options include vasoconstrictor drugs to counteract splanchnic arterial vasodilation and plasma volume expansion by intravenous albumin infusion. In patients with HRS unresponsive to pharmacological treatment and with conventional indications for kidney replacement therapy (KRT), such as volume overload, uremia, or electrolyte imbalances, KRT may be applied as a bridging therapy to transplantation. Other interventions, such as transjugular intrahepatic portosystemic shunt, and artificial liver support systems have a very limited role in improving outcomes in HRS. Although recently developed novel therapies have potential to improve outcomes of patients with HRS, further studies are warranted to validate the efficacy of these novel agents.

Recent advances in pathophysiology, diagnosis and management of hepatorenal syndrome: A review

Hepatorenal syndrome with acute kidney injury (HRS-AKI) is a form of rapidly progressive kidney dysfunction in patients with decompensated cirrhosis and/or acute severe liver injury such as acute liver failure. Current data suggest that HRS-AKI occurs secondary to circulatory dysfunction characterized by marked splanchnic vasodilation, leading to reduction of effective arterial blood volume and glomerular filtration rate. Thus, volume expansion and splanchnic vasoconstriction constitute the mainstay of medical therapy. However, a significant proportion of patients do not respond to medical management. These patients often require renal replacement therapy and may be eligible for liver or combined liver-kidney transplantation. Although there have been advances in the management of patients with HRS-AKI including novel biomarkers and medications, better-calibrated studies, more widely available biomarkers, and improved prognostic models are sorely needed to further improve diagnosis and treatment of HRS-AKI.

Spontaneous peritoneal drainage following paracentesis in a hospitalized patient with resolution of type 1 hepatorenal syndrome

The hepatorenal syndrome develops in a small percentage of patients with advanced liver disease. The pathogenesis involves intravascular volume contraction secondary to pooling of blood in the splanchnic vessels, stimulation of the sympathetic nervous system and the renin-angiotensin-aldosterone pathway, and increased intra-abdominal pressure secondary to the formation of large volumes of ascitic fluid. The treatment options are limited, and liver transplant is the only definitive form of management. Here we suggest an alternative approach to treating hepatorenal syndrome based on the unexpected continuous peritoneal drainage in a 36-year-old man hospitalized with hepatic encephalopathy and hepatorenal syndrome. A total of 11.2 L ascitic fluid drained over 5 days from a paracentesis puncture site with marked improvement in renal function; the creatinine decreased from 3.3 mg/dL to 0.7 mg/dL and the BUN decreased from 42 mg/dL to 10 mg/dL. The discussion with this case report summarizes the pathogenesis, including the effect of intra-abdominal pressure, of the hepatorenal syndrome, outlines medical management, and makes a proposal for clinical study based on this case.

Predictors of renal recovery in recipients of liver transplant alone who met 2017 simultaneous liver-kidney transplant criteria

BACKGROUND

Severe renal dysfunction is common among liver transplant (LT) candidates and often prompts simultaneous liver-kidney transplantation (SLKT) consideration. In view of 2017 United Network of Organ Sharing (UNOS) criteria for SLKT, we investigated the likelihood and predictors of renal recovery among patients who met the aforementioned criteria yet received liver transplant alone (LTA).

METHODS

We retrospectively analyzed relative renal recovery (RRR; increase in eGFR to >30 ml/min) in adult LTA recipients between 1/2009 and 1/2019.

RESULTS

Of 1165 LT recipients, 54 met 2017 UNOS criteria, with 37 receiving LTA. RRR occurred in 84% of LTA recipients, none of whom had pre-LT eGFR <20 ml/min. Sustained RRR (>180 days) occurred in 43% of patients. While prolonged pre-LT severe renal impairment (eGFR <30 ml/min) predicted failure to have sustained RRR (HR .19 per 90-day, CI .04-.87, p < .005), having an eGFR measurement of >30 ml/min within 90 days pre-LT (HR 5.52, CI 1.23-24.79, p .01) associated with achieving sustained RRR. Sustained RRR was protective against the composite outcome of renal replacement therapy, kidney transplant, and death (HR .21, p .01).

CONCLUSION

LT candidates who meet 2017 UNOS criteria for SLKT yet undergo LTA can still have relative renal recovery post-LT, exceeding 80% on short-term follow-up and 40% on long-term follow-up. eGFR trends within 90 days pre-LT can predict sustained renal recovery, which appears protective of adverse outcomes. These recovery rates advocate for applying the more restrictive criteria for SLKT outlined in this article and increasing utilization of the safety net (SN) policy for those who do not meet the proposed criteria.

Peritransplant Renal Dysfunction in Liver Transplant Candidates

Renal function is intricately tied to Model for End-Stage Liver Disease score and overall prognosis among patients with cirrhosis. The estimation of glomerular filtration rate (GFR) and etiology of renal impairment are even more magnified among cirrhotic patients in the period surrounding liver transplantation. Novel biomarkers including cystatin C and urinary neutrophil gelatinase-associated lipocalin have been demonstrated to more accurately assess renal dysfunction and aid in the diagnosis of competing etiologies. Accurately identifying the severity and chronicity of renal dysfunction among transplant candidates is an imperative component with respect to stratifying patients toward simultaneous liver-kidney transplantation versus liver transplantation alone.

A meta-analysis on the prevalence of chronic kidney disease in liver transplant candidates and its associated risk factors and outcomes

Pre-liver transplant (LT) chronic kidney disease (CKD) has emerged as a leading cause of post-operative morbidity. We aimed to report the prevalence, associated risk factors, and clinical outcomes in patients with pre-LT CKD. Meta-analysis and systematic review were conducted for included cohort and cross-sectional studies. Studies comparing healthy and patients with s pre-LT CKD were included. Outcomes were assessed with pooled hazard ratios. 15 studies were included, consisting of 82,432 LT patients and 26,754 with pre-LT CKD. Pooled prevalence of pre-LT CKD was 22.35% (CI: 15.30%-32.71%). Diabetes mellitus, hypertension, viral hepatitis, and non-alcoholic fatty liver disease, and older age were associated with increased risk of pre-LT CKD: (OR 1.72 CI: 1.15-2.56, P = 0.01), (OR 2.23 CI: 1.76-2.83, P < 0.01), (OR 1.09; CI: 1.05-1.13, P < 0.01), (OR 1.73; CI: 1.10-2.71 P = 0.03), and (MD: 2.92 years; CI: 1.29-4.55years; P < 0.01) respectively. Pre-LT CKD was significantly associated with increased mortality (HR 1.38; CI: 1.2-1.59; P < 0.01), post-LT end-stage renal disease and post-LT CKD. Almost a quarter of pre-LT patients have CKD and it is significantly associated with post-operative morbidity and mortality. However, long-term outcomes remain unclear due to a lack of studies reporting such outcomes.

Hepatorenal syndrome: pathophysiology, diagnosis, and management

Hepatorenal syndrome (HRS), the extreme manifestation of renal impairment in patients with cirrhosis, is characterized by reduction in renal blood flow and glomerular filtration rate. Hepatorenal syndrome is diagnosed when kidney function is reduced but evidence of intrinsic kidney disease, such as hematuria, proteinuria, or abnormal kidney ultrasonography, is absent. Unlike other causes of acute kidney injury (AKI), hepatorenal syndrome results from functional changes in the renal circulation and is potentially reversible with liver transplantation or vasoconstrictor drugs. Two forms of hepatorenal syndrome are recognized depending on the acuity and progression of kidney injury. The first represents an acute impairment of kidney function, HRS-AKI, whereas the second represents a more chronic kidney dysfunction, HRS-CKD (chronic kidney disease). In this review, we provide critical insight into the definition, pathophysiology, diagnosis, and management of hepatorenal syndrome.