Kidney Swelling (Hydronephrosis)
Hydronephrosis is swelling of the kidney. It can be classified as mild, moderate or severe and be caused by many different reasons. Kidney or ureteral stones, urinary retention, stricture (narrowing of the drainage of the kidney), BPH, UPJ obstruction, infections, cancers inside the urinary tract, cancers outside the urinary tract, and congenital anomalies are some of the most common causes.
All hydronephrosis needs to be evaluated by a urologist. As long as it is treated within 6-8 weeks of onset, damage can be reversed. However, if the hydronephrosis is not treated within 6-8 weeks, you can have permanent damage to the kidney and potential kill the kidney.
Symptoms:
If the hydronephrosis comes on suddenly (like with a kidney stone), most people will experience symptoms such as:
- Flank pain- sharp/stabbing
- Nausea
- Vomiting
If it is a chronic hydronephrosis or comes on very slowly (like with a slow growing tumor), sometimes the symptoms are very mild or there are no symptoms.
- Flank pain- dull ache or no pain
- Mild nausea or no nausea
- UTI
- Lab abnormalities (low GFR) on routine screening tests
Risk Factors:
- Kidney stones- the most common cause of hydronephrosis.
- Any type of abdominal or metastatic cancer
- Previous instrumentation with ureteroscopy
- Previous abdominal surgery
- Older men with large prostates and urinary retention
Evaluation:
Hydronephrosis can only be diagnosed with imaging- usually an abdominal ultrasound, CT scan, or MRI will show hydronephrosis. A CT scan of the abdomen and pelvis is the best test because it can not only show you the hydronephrosis, but also look to see what may be causing it.
Another way to evaluate would be with a cystoscopy and retrograde pyelogram- passing a camera into the bladder and shooting dye backwards toward your kidney. This is done under anesthesia.
A Lasix renal scan can also be used in the evaluation as well in certain cases.
Your doctor will usually use the imaging studies in conjunction with blood tests, urinalysis and your physical symptoms to decide how urgent your treatment should be.
Treatment:
The easiest way to solve hydronephrosis is to remove what is causing it. Whether that is a stone, a tumor, a prostate, or scar tissue. Sometimes that is easy and sometimes it cannot be done or may take time to resolve.
In most cases, a stent can be placed that will bypass the obstruction and let the kidney drain. A stent is a flexible, plastic (polyurethane or silicone) tube that is about 12 inches long and will curl in the kidney and bladder. It is placed under anesthesia to protect the kidney until the cause of the hydronephrosis is resolved. A stent usually stays in for a week but can stay as long as 3-6 months at a time if needed. No ureteral stents are permanent, so if you have one placed it needs to be removed or exchanged. Stents are usually removed in the office with a small camera that takes about 1 minute or less to do.
If you are told you have hydronephrosis, please see a urologist. Dr. Shaba can discuss with you what is causing it and what can be done to resolve it.
For more information please visit: https://www.urologyhealth.org/urology-a-z/all-conditions
