Indictions
When a patient presents with kidney failure, it is often important for a biopsy of the kidney to be performed. This may provide some clues to the reason why a patient's kidneys stopped working and may help to direct treatment.
Procedural Details
During a biopsy of the kidney, the patient is positioned face down on an examination table. Since the kidneys are in the back of the abdomen, it is often easiest to see them when looking from the back. We use ultrasound for this purpose. Once the patient is comfortable on the table, an ultrasound is performed in order to determine the exact position of the kidney and the best (or most accessible) part of the kidney to target for a biopsy. Once this has been determined, a small needle is advanced from the skin of the back directly into the outer part of the kidney. This is known as the renal cortex and it contains a part of the working unit of the kidney called the glomeruli. Our goal is to obtain as many glomeruli as possible with the biopsy because this is the part of the kidney that the pathologist needs to see in order to come up with a diagnosis for the patient. Since it is so important for us to obtain glomeruli with our biopsy specimens, a representative from the pathology department is often involved during the biopsy to help us know when enough tissue has been obtained. At that point, the needle is removed and pathology can begin their evaluation.
Results
Since pathology is directly involved during the biopsy, it is rare for us to not supply enough tissue to them. Therefore, the renal biopsies we perform almost always enable a diagnosis to be made. Patients undergoing a renal biopsy may experience some flank pain on the side of the biopsy. This usually goes away within a day or two. In addition, it is common for patients to detect some blood in the urine. This always goes away on its own. If the bleeding seems heavy or persists for several days, we would want to know so that we can help determine the exact reason for the bleeding. With minimally invasive, catheter-based techniques, post-biopsy bleeding that does not go away on its own can usually be addressed without surgery.