Percutaneous nephrolithotomy (PCNL)

A percutaneous nephrolithotomy (PCNL) is a procedure to remove a kidney stone or stones. Percutaneous means ‘through the skin’ and nephrolithotomy means ‘taking stones out of the kidney’.

From the results of your tests, you have a stone or stones in your kidney. Not all kidney stones cause symptoms, but yours may have caused significant problems, such as pain or infection. If nothing is done to remove them, they will continue to grow and could damage your kidney.

Possible alternatives include:

• open surgery.
• extracorporeal shock wave lithotripsy (ESWL) and
• ureteroscopy (URS).

A PCNL generally removes more stone fragments than ESWL and URS and has a shorter recovery time than open surgery. However, this will depend on your individual circumstances. Your consultant will discuss these with you in more detail if they are appropriate for you. PCNL offers the best chance of clearing large stones (>2cm or multiple) with one procedure.

You will usually be required to stop blood-thinning medications such as warfarin, aspirin, clopidogrel and dipyridamole before surgery, but please discuss with your specialist. Do not make any changes to your usual medicines, unless your specialist has told you to do so.You will be given a pre-assessment appointment to assess your suitability and fitness for surgery and the anaesthetic. This will also give you the opportunity to ask any further questions before you come into hospital for the procedure. You must come to this appointment; if you do not, we may have to delay or cancel your surgery.

Because of the risk of infection following stone surgery, if you have an infection before the operation the surgery will be postponed. At pre-assessment a urine sample will always be sent. If the urine sample confirms infection your GP will prescribe antibiotics.

If you feel you have an infection whilst waiting for your surgery:

• give a urine sample to your GP.
• contact us as your surgery may need to be postponed to allow the infection to be cleared. If this happens we will give you a new date for surgery.

You will be admitted on the day of surgery, and will meet the surgeon and anaesthetist. You are having a general anaesthetic, so please do not eat for six hours before your surgery. This includes sweets and chewing gum. You can have non-fizzy water up to two hours before your surgery.

You will need to sign a consent form and be marked to identify which side your operation will be. This consent gives the consultant permission to operate on you and confirms that you understand what the procedure involves.

Please bring all of your medications, including prescription medications, medication you have bought or alternative medicines, such as herbal remedies, so we know what you are taking. Unless your doctor or nurse tells you otherwise, please take your tablets as prescribed, with a small sip of water, on the day of your surgery.

You will be asked to change into a hospital theatre gown and elasticised stockings. These stockings help to reduce the possibility of clots (deep vein thrombosis or DVT) forming in your legs during surgery. These should be worn throughout your hospital stay.

The operation begins by inserting a telescope-like instrument (known as a cystoscope) into the bladder. A tube is then passed up the ureter into the kidney. This tube allows the kidney to be filled with dye (contrast medium) to allow your surgeon to localise the kidney with x-rays.

You are moved on to your front (lying face down). With the aid of the x-ray machine, the kidney is punctured with a fine needle. The needle position is confirmed by either outflow of urine or dye from the needle. Once the kidney has been entered, a 1.5cm incision is made in the back and the needle tract into the kidney is then stretched (dilated) to allow a telescope to be passed into the kidney. The needle tract is then dilated. A scope and other stone fragmentation tools such as a laser or an ultrasonic probe will be inserted through this tract for stone fragmentation and removal. The whole procedure usually takes 2-3 hours.

After the operation, a tube is left in the kidney and a catheter is left in the urethra (the tube which carries urine from your bladder and out of your body) to ensure good urinary drainage. These are removed over the next few days depending on clinical progress and will be reviewed daily by the medical team.

Most procedures have possible side-effects. But, although the complications listed below are well recognised, most patients do not suffer any problems.

Common (greater than 1 in 10)

• Blood in the urine (temporary).
• Raised temperature (temporary).

Occasional (between 1 in 10 and 1 in 50)

• Occasionally the surgeon will need to make more than one puncture.
• There is no guarantee all the stones will be removed and you may need further operations.
• You may get new stones.
• The surgeon may not be able to get access to the kidney and you may need further surgery.

Rare (less than 1 in 50)

• Severe kidney bleeding requiring transfusion, embolisation or, as a last resort, removal of kidney.
• Damage to the lung, bowel, spleen, or liver which will need surgery.
• Kidney damage or infection needing further treatment.
• Irrigating fluids may get into the blood system and cause a strain on the heart.

Hospital-acquired infection

• Colonisation with MRSA (0.9% - 1 in 110).
• Clostridium difficile bowel infection (0.01% - 1 in 10,000) l MRSA bloodstream infection (0.02% - 1 in 5000).

The rates for hospital-acquired infection may be greater in high-risk patients, for example those patients

• with long-term drainage tubes;
• who have had their bladder removed due to cancer;
• who have had a long stay in hospital; or
• who have been admitted to hospital many times.