Glomerular Filtration Rate (GFR) is a measure of kidney function, estimating how much blood passes through the tiny filters in the kidneys, called glomeruli, each minute. Nephrectomy is a surgical procedure involving the removal of all or part of a kidney, often performed for conditions like kidney cancer or severe damage. This article explains the changes in GFR following a nephrectomy, along with subsequent adaptations and required care.
Initial Changes to Kidney Function
Immediately following a nephrectomy, a reduction in GFR is expected. This occurs because the body’s total filtering capacity is reduced with the loss of one kidney.
This immediate GFR decrease is an expected physiological response as the body adjusts to the sudden absence of one kidney. The drop can be significant, often reflecting the loss of approximately 50% of the initial filtering capacity.
The Remaining Kidney’s Adaptation
Following the initial decline, the remaining kidney adapts to compensate for the lost function. This involves two mechanisms: compensatory hypertrophy and hyperfiltration. Compensatory hypertrophy is an increase in the size of the remaining kidney, driven by an increase in individual kidney cell size (hypertrophy) and, to a lesser extent, cell number (hyperplasia).
Simultaneously, the remaining kidney undergoes hyperfiltration, meaning its individual filtering units, the glomeruli, work harder and filter more blood per minute. This increased workload helps to partially restore the overall GFR. While GFR typically does not return to its pre-surgery level, substantial recovery occurs, reaching approximately 70% of the original function. This adaptive process unfolds over weeks to months, with significant functional recovery observed within the first year after surgery.
Factors Influencing Long-Term Kidney Health
Several factors influence long-term GFR and kidney health after a nephrectomy, leading to varied outcomes. The health and function of the remaining kidney before surgery play a role; a healthier kidney has greater compensatory capacity. Patient age also impacts recovery, as older individuals may have less adaptive capacity.
Underlying health conditions, such as diabetes and high blood pressure, can affect kidney function post-nephrectomy and accelerate GFR decline. The reason for nephrectomy, whether for donation or disease, also influences long-term outcomes, with donors generally having better pre-existing kidney health. Additionally, the type of nephrectomy performed, such as partial versus radical, impacts preserved function, with partial nephrectomy typically preserving more kidney mass and function.
Life with One Kidney: Monitoring and Care
Living with one kidney allows for a full and healthy life, but it requires monitoring and care to maintain kidney health. Regular medical follow-ups are important, including monitoring GFR, creatinine levels, and blood pressure. These tests help assess how well the remaining kidney is functioning and detect any potential issues early.
Lifestyle adjustments are also important for supporting the single kidney. Maintaining adequate hydration by drinking plenty of water, consuming a balanced diet, and engaging in regular exercise contribute to kidney well-being. It is advisable to avoid medications harmful to the kidneys, such as certain nonsteroidal anti-inflammatory drugs (NSAIDs), unless prescribed. Managing existing conditions like hypertension and diabetes through medication and lifestyle is necessary to prevent further strain on the kidney. While most individuals lead healthy lives with one kidney, adherence to medical advice is important for long-term health and to minimize the risk of chronic kidney disease.