Pathogenetic mechanism
The development of reflux nephropathy is based on a cascade of hemodynamic and hydrodynamic disorders triggered by impaired normal urine outflow. The process of pathological changes includes several successive stages:
- Pressure increase: Against the background of negative hydrodynamics, a significant increase in pressure occurs inside the renal pelvis.
- Intrarenal reflux: Increased pressure causes urine from the pelvicalyceal system to be refluxed directly into the parenchymal tissue.
- Microcirculation impairment: The abnormal presence of urine in the tissues and mechanical pressure cause secondary microcirculation impairment in the organ.
- Ischemia and sclerosis: Lack of blood supply leads to renal tissue ischemia, against the background of which (as well as due to constant hydrodynamic impacts and superimposed infection) the process of focal sclerosis and irreversible atrophy is initiated.
Radiological presentation
For the diagnosis of reflux nephropathy, visualization of the affected organ plays a key role. On the presented urogram, a number of specific diagnostic signs indicating a far-advanced damage process can be distinguished:
- Reduction in kidney size: The pathology is characterized by a pronounced decrease in organ volume. The area of the affected kidney may be three times less than normal age values.
- Parenchymal thinning: Local or diffuse loss of functioning renal tissue mass is observed. As a classic example, a sharp thinning in the lower pole area of the organ is often visualized.
- Contour deformation: The external contours of the kidney lose their physiological definition and become smoothed and uneven. This unevenness indicates the formation of gross scar retractions that appear at the site of past inflammation foci and subsequent atrophy.
Clinical evaluation and management
In the clinical evaluation of a patient's condition, it is extremely important to consider one non-obvious fact: the severity of the vesicoureteral reflux itself does not always directly correlate with the degree of renal function loss. Even with moderate reflux, severe sclerotic changes can be observed, and vice versa.
The choice of optimal management tactics in pediatric practice should be based on strict consideration of three fundamental factors:
- Precise determination of the primary cause of reflux.
- Determination of the severity grade of reflux.
- Thorough assessment of the remaining functional reserve of the affected kidneys.
To memorize the pathogenesis, use the chain "PIIS": Pressure increase → Intrarenal reflux → Ischemia (microcirculatory) → Sclerosis.
Class and exam questions
What is the primary cause of sclerosis foci formation in reflux nephropathy?
Focal sclerosis of renal tissue develops due to constant hydrodynamic stress (intrarenal urinary reflux), secondary tissue ischemia, and the inevitable addition of an infectious process.
How do the size and shape of the kidney change on a urogram?
On the urogram, the affected kidney is significantly reduced in size (up to a 3-fold reduction in area), its parenchyma is thinned, and the outer contour becomes uneven and smoothed due to scar retractions.
Does the degree of renal function loss directly depend on the severity of vesicoureteral reflux?
No, the severity of vesicoureteral reflux does not always directly correlate with the degree of renal function loss. Assessment must be comprehensive.
What else to study on this topic
- Definition and assessment of renal functional reserve in children
- Methods for determining the cause of vesicoureteral reflux
- The role of infection in accelerating renal tissue sclerosis
- Classification of vesicoureteral reflux grades
- Differential diagnosis of causes of renal contour deformation
Master the entire topic in the Pediatrics course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Reflux nephropathy" and 3,738 other subject pages
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 71 video lessons on the subject
Other topics in "Chapter 8. Kidney and Urinary Tract Diseases"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.