Hydronephrosis

Hydronephrosis is a condition when the kidneys swell up due to the accumulation of urine. This condition is caused due to the inability of the kidney to expel urine from the body completely. Hydronephrosis can be sudden or chronic, partial or complete. The condition may affect either one (unilateral hydronephrosis) or both the kidneys (bilateral hydronephrosis). The reasons for urinary retention could be either a blockage of the outflow of urine or the reverse flow of urine from the urinary bladder.

Though the retention of urine in kidneys can cause various symptoms, one of the significant symptoms is pain. Hydronephrosis may or may not produce symptoms. The symptoms depend on the severity of the blockage, and some of them are:

1. Abdominal or groin pain
2. Pain on the side and back of the abdomen, known as flank pain
3. Painful urination
4. Increased frequency and urgency of urination
5. Incomplete urination 
6. Nausea
7. Fever due to urinary tract infection
8. Vomiting
9. Blood in urine
10. Weakness or malaise

Hydronephrosis is a condition caused due to various other illnesses or underlying causes that block the ureter (the tube that carries urine from the kidneys to the urinary bladder). The blockage may be due to:

1. The obstruction due to kidney stones
2. Birth defect of the urinary system
3. Blood clot
4. Narrowing of the ureter due to scarring of the tissue from a previous injury or a surgery
5. Enlarged prostate
6. Enlarged uterus during pregnancy
7. Disorders of nerves that supply the bladder
8. Vesicoureteral reflux is a condition where there is a backflow of urine to the kidneys from the urinary bladder
9. Inflammation in the ureter due to urinary tract infection
10. Blockage of ureter, bladder, pelvis, or abdomen due to tumours or cancers
11. Uterine prolapse (when the uterus of a woman sags or slips out of its normal position)
12. Ureterocele, when the lower part of the ureter bulges into the bladder
13. Cystocele is a fallen bladder when the wall between the vagina and  bladder weakens, letting the urinary bladder to sag into the vagina

The condition can be diagnosed with the help of:

1. Patient history – Your urologist will enquire about your medical history and ask you about your family medical history.
2. Clinical examination – You will be subjected to a physical examination. Your urologist will:
   1. Ask you about the symptoms you are having and examine the areas around the kidneys and bladder for swelling or tenderness.
   2. Look for the swelling in the pelvic area (area below the abdomen and in between hip bones where the bladder and rectum are located)
   3. Ask men to undergo a rectal exam to check for an enlarged prostate 
   4. Ask women to undergo a pelvic exam to find out if there are any problems with the uterus or ovaries
3. Investigations – Once you are evaluated physically, your urologist may want you to undergo a set of tests like:
   1. Urine test to diagnose if there is any presence of infection, stone crystals, blood, or bacteria in urine
   2. Blood tests like complete blood count (to diagnose an infection), creatinine, estimated glomerular filtration rate (GFR) and blood urea nitrogen (to check the functioning of kidneys)
   3. Imaging procedures like ultrasound, computed tomography (CT) scan or magnetic resonance imaging (MRI) scan

The objective of treatment for hydronephrosis is to treat the primary cause of urine retention. Therefore, the treatment also depends on the underlying disorder and its severity.

Some of the treatment options for hydronephrosis, depending on the various primary conditions and their severity, are:

Acute or sudden hydronephrosis:

1. A urologist will drain off the excess urine from the kidneys to reduce the swelling using one of the two ways mentioned below.
2. Your urologist will insert a soft tube or stent called a nephrostomy tube into the kidney through your skin to drain off the excess urine.
3. Your urologist will place a soft plastic tube called a ureteral stent in between the kidney and bladder during a cystoscopy (endoscopy of the urinary bladder through the urethra).

Hydronephrosis due to small stones in kidneys or ureter: Some of the treatment options available for the condition are:

1. Ureteroscopy: This is a procedure that is preferred by morbidly obese and pregnant women to treat kidney stones. For this procedure, your urologist will first place a thin tube with special instruments into the urethra and then break up the stones and remove them. This is a preferred method used to treat the stones located in the bladder or the lower half of the ureter. Ureteroscopy may be used in combination with other techniques such as pulsed dye laser or electrohydraulic lithotripsy to break up the stones.
2. Shock wave lithotripsy: This is the most common procedure used to treat kidney stones. Here high-energy shock waves are directed to the kidney stones to break them up into very tiny pieces, almost the size of the dust, so that they can pass out of the body easily.

Surgery: Surgery is the most preferred procedure to remove large stones and tumours that may be blocking the flow of urine.

Medications: A urologist may prescribe you some medications to relieve the pain and reduce the infection, such as:

1. Antibiotics to prevent or treat urinary tract infection 
2. Painkillers to relieve the pain

Some of the complications that may occur if hydronephrosis is left untreated are:

1. Flank pain (pain in the lower back)
2. Urinary tract infection 
3. Kidney failure (loss of function of the kidneys)

Disease Progression 

Though there are various types of grading systems available for the older population, there is not one gold standard for the same. Onen grading system is considered a standard one used by the sonographers and urologists for the evaluation and measurement of kidneys in infants.

 Disease progression for both prenatal (before birth) and postnatal (after birth) ureteropelvic junction hydronephrosis (UPJHN) in children can be graded using the Onen grading system. The disease stages are graded into four stages depending on the various changes (damages) in the structure of the kidneys.