From the Research
Hepatorenal syndrome (HRS) is a severe complication of advanced liver disease characterized by kidney failure in patients with cirrhosis, resulting from intense renal vasoconstriction due to complex hemodynamic changes in the splanchnic and systemic circulation, as recently described in 1. The pathogenesis of HRS involves several key factors, including:
- Portal hypertension from cirrhosis causing splanchnic vasodilation, leading to reduced effective arterial blood volume
- Activation of compensatory mechanisms, such as the renin-angiotensin-aldosterone system, sympathetic nervous system, and antidiuretic hormone release, which cause renal vasoconstriction to maintain blood pressure
- Decreased production of renal vasodilators like prostaglandins and increased levels of vasoconstrictors such as endothelin-1
- Bacterial translocation from the gut and subsequent systemic inflammation, which further exacerbate these hemodynamic disturbances
- Cardiac dysfunction (cirrhotic cardiomyopathy) may develop, reducing cardiac output and worsening renal perfusion, as noted in 2. The combination of these factors leads to profound renal hypoperfusion, reduced glomerular filtration rate, and ultimately kidney failure without structural kidney damage, making liver transplantation the definitive treatment for HRS, as stated in 1 and 2. Some of the key points to consider in the pathogenesis of HRS include:
- The importance of splanchnic vasodilation and reduced effective arterial blood volume in triggering the compensatory mechanisms that lead to renal vasoconstriction
- The role of systemic inflammation and cirrhotic cardiomyopathy in exacerbating the hemodynamic disturbances and worsening renal perfusion, as discussed in 3 and 2
- The potential for liver transplantation to address the underlying cause of these circulatory abnormalities and improve outcomes for patients with HRS, as highlighted in 1 and 2.