What is a Percutaneous Nephrolithotripsy?

Percutaneous Nephrolithotripsy, or the removal of stones from the kidney, is considered a minimally invasive procedure. It is done by puncturing wounds through the skin. It is a widely used technique to remove stones in the kidney that are more than 2cm in size.

Why is percutaneous nephrolithotripsy done?

Percutaneous nephrolithotomy can be done for one following reasons:

• Kidney stones that are larger than 2cm in diameter
• If larger stones are present in the ureter
• Infection being the cause of large kidney stones
• Restricting the flow of urine from the kidney
• Stones that cannot be broken by extracorporeal shock wave lithotripsy
• If the person is obese
• When other therapies fail

What are the preparations that have to be taken before the surgery?

• For the effective clearance of the kidney stones and to make the proper incision, an X-ray image is required which allows easier determination of the relationship between the stones within the kidney and its nearby structures.
• Eating and drinking anything for 6 hours is avoided before the surgery.
• Medications like blood-thinning agents and non-steroidal anti-inflammatory drugs are avoided for 7- 10 days before the treatment
• To check whether urine is sterile, a mid-stream urine test is required.
• Kidney function studies, urine culture tests, and complete blood count tests are also done before the treatment 
• Urine is checked for signs of infection
• To locate stones in the kidney, some blood tests and computerized tomography are done. 

How is percutaneous nephrolithotomy done?

• The operation is generally performed under anesthesia where the entire procedure lasts for 2-3 hours. 
• The stone in the kidney is located by a retrograde pyelogram which helps in visualizing the ureter and the kidney
• With the needle of percutaneous nephrolithotomy, a small 1-centimeter cut is made in the lumbar region by passing through the pelvis region of the kidney
• Fluoroscopy is used to confirm the position of the needle
• Into the pelvis, a guide wire is passed through the needle
• With the guide wire remaining in the pelvis, the needle is withdrawn
• The working sheath is introduced by passing the dilators over the guide wire
• Small stones that are present are taken out by passing a nephroscope inside the working sheath
• Ultrasound probes are used if there is the presence of any big stones that need to be crushed.
• Stone fragments are later removed
• An antegrade technique is used to create the tract between the kidney and the flank skin by advancing the needle into the kidney from the flank skin.
• Alternatively, a retrograde technique is used where a flexible ureteroscope is used to pass a thin wire from inside the kidney to outside the flank. An advantage of the retrograde technique is the prevention of radiation to the patient as well as to the surgeon.

What are the advantages of having percutaneous nephrolithotomy? 

• Using a minimally invasive procedure, large or complicated kidney stones are treated with a relatively small incision.
• It has a relatively shorter hospital stay post-surgery which might be around 3-4 days.

What precautions need to be taken after the surgery?

• The recovery phase which generally lasts for about 2-3 weeks is to be taken easily
• Make sure that there is minimal distress from the wound
• To prevent infection, oral antibiotics are generally prescribed
• Having fevers, chills and bleeding in the urine has to be reported immediately
• To ensure that urine correctly drains into the bladder, a urinary stent is left, which will be removed later
• Lifting anything heavier, pushing and pulling are to be avoided for at least 2 to 3 weeks after the surgery
• An x-ray test is done 4-6 weeks after the surgery to see if there are any leftover kidney stones and also to ensure that urine is draining normally from the kidney