This page tells you about the procedure known as a renal cryoablation. It explains what is involved and what the possible risks are. It is not meant to be a substitute for informed discussion between you and your doctor but can act as a starting point for such a discussion.
Your procedure will take place in the Radiology department. The radiology department may also be called the ‘X-ray’ or ‘Imaging’ department. It is the facility in the hospital where radiological examinations are carried out, using a range of x-ray equipment, such as a CT (computed tomography) scanner, an ultrasound machine and an MRI (magnetic resonance imaging) scanner.
Interventional Radiologists are doctors specially trained to carry out imaging guided complex procedures. They are supported by radiographers who are highly trained to carry out x-rays and other imaging procedures. Also, specialist nurses who are highly trained in interventional procedures, sedation, recovery and patient support.
Key Points of renal cryoablation
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A non-surgical (minimally invasive) technique to treat renal cancer.
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It works by freezing the cancer which kills the cells.
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Alternative to surgical partial nephrectomy.
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It has a quicker recovery rate than surgery, a low complication rate and minimal effect on kidney function.
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Our results at UCH show a 95% chance that the disease will not have come back at 5 years.
Understanding the kidney
The kidneys are bean shaped organs located in your lower back on either side of your spine. Most people have two kidneys, and each is the size of your fist. The kidneys play a vital role in filtering the blood and excreting waste products through urine. They also ensure your blood pressure is well controlled as well as playing a role in making blood cells. The kidneys take blood from the renal artery (red). Blood is taken away from the kidney from the renal vein (blue). Urine is produced by the kidney and passes through a tube called the ureter into the bladder where it is ultimately excreted.
Figure 1. The kidney
Renal cell cancer
Renal cell cancer (RCC) is the sixth most frequently diagnosed cancer worldwide. Detection of RCC is on the rise, and one reason is due to more ‘incidental’ tumours being detected on routine scans. Different treatment strategies will be offered to you based upon how advanced it is.
Cryoablation is a procedure that uses ice to freeze and destroy abnormal cells in the tumour in your kidney. The procedure is normally performed whilst you are asleep (general anaesthetic) but can be performed under sedation and local Anaesthetic. Needles are placed into the kidney tumour using image guidance (Computed Tomography- CT).
Temperatures as low as minus 120 degrees Celsius are produced through the needles using Argon gas, which forms a ball of ice in the tumour, causing death of the abnormal cells. The number and type of needles will be tailored to the size of the tumour to minimise how much normal kidney tissue is affected.
We have been using cryoablation at UCH for over 10 years. It is a procedure approved by the National Institute of Health and Clinical Excellence (NICE).
When appropriate tumours are selected, cryoablation is an extremely effective treatment strategy. If necessary, the procedure can be repeated. We have followed-up our own patients and over 5 years, 95% (95 patients out of 100) do not require any further treatment. This compares well with surgery but has the added advantage of being minimally invasive. After treatment, you will generally be able to resume your normal daily activities a few days afterwards.
There are many forms of treatment on offer for kidney tumours. The decision as to what type of treatment is suitable for you have been considered by a team of surgeons, oncologists, and interventional radiologists (IR), who have decided that cryoablation is an option for your tumour.
Surgery
Removal of the tumour and part of the kidney (partial nephrectomy) or the whole kidney (nephrectomy) are the surgical options available.
Observation
This involves close follow up of the tumour by scanning your kidneys over a period to ensure it has not grown.
Other forms of ablation:
Radiofrequency ablation (RFA) or Microwave ablation (MWA)
This is a method whereby an electric current (RFA) or microwave energy (MWA) is used to heat up the tumour under ultrasound/CT guidance.
Please do not hesitate to ask if you have any further questions about the alternative treatment strategies.
Cryoablation is generally a safe procedure, although no procedure is without risk. We take all precautionary measures to minimise the risks and to ensure that the procedure is appropriate for you. The risks encountered can also be influenced by where the tumour is in your kidney.
Immediate risks - Bleeding
We monitor you for immediate complications that may happen straight away including bleeding from the needle tract site or from the kidney. If bleeding is suspected to be coming from the kidney, we may do a CT scan to monitor this. Rarely, a further procedure may be needed to stop the bleeding if the body is unable to by itself.
Problems that may happen later
Post ablation syndrome is a flu-like illness that may occur 3-5 days after the procedure. It occurs in around 1 in 4 patients and may require simple analgesia such as paracetamol to help you.
Other risks
Kidney infections are rare but if they occur, would require antibiotics. We give you a dose of antibiotic before the procedure to reduce risks.
Damage to surrounding structures
We are incredibly careful with our needle positions but there is a small risk of damage to surrounding organs including your bowel, lung, and the ureter (tube connecting your kidney to your bladder).
We have followed up our patients here at UCH who underwent cryoablation for their kidney tumours over a 5-year period. The risk of having a major complication is 2% (2 patients in 100), and these include things such as major bleeding and injury to the lung.
The Interventional Oncology team will be looking after you at UCH.
The ablation is performed by a consultant radiologist who has a particular expertise in guiding needles using imaging. There are several consultant radiologists, members of the interventional oncology service, who deliver this treatment. The team works with other doctors involved in your care.
Interventional Radiologists:
Dr Miles Walkden - Clinical Lead for the ablation service
Dr Graham Munneke - Consultant Interventional radiologist
Dr Ahmed Al-Nowfal - Consultant Interventional radiologist.
The other members of the team include our two clinical nurse specialists Analie Morales and Alfred Tan and our coordinator Lina Lopez Hegarty.
The procedures are carried out at University College Hospital (UCH) by the Interventional Oncology team (IOS).
After you have been seen in the clinic at the Royal Free we will ask you to attend a pre-operative assessment appointment at UCH. The purpose of this appointment is to ensure you are well enough to go ahead with the procedure. We will ask about your medical/surgical history and carry out any necessary clinical examinations such as blood tests and an electrocardiogram (ECG). It will help us if you could also bring written details of your medicines to the appointment.
We will also give you written information about when to stop eating and drinking before the procedure, what to bring with you, when you should arrive and the need for an escort home. We will also tell you what medicines should be stopped before the procedure.
When you come in for the procedure, please bring all your medications with you.
Ureteric Stent
If your tumour lies close to the ureter we may ask that you have a ureteric stent placed before the cryoablation to help protect it from the ice. You will be informed about this in the clinic appointment prior to deciding on which treatment you want. The procedure is performed at the Royal Free Hospital and requires a short general anaesthetic. The stent will be in for 2-6 weeks following the procedure and will then be removed at the Royal Free under local anaesthetic.
On the day of the procedure
On arrival you will be checked into the department by an imaging nurse. The nurse will fill in some paperwork and do some clinical observations-like blood pressure and pulse. You will be asked to put on a hospital gown and will be given some stockings to wear on your legs to reduce the risk of blood clots.
The Radiologist will come and explain the procedure to you and sign off the Consent form with you. This is where you have the opportunity to talk to the Radiologist doing your procedure and they will be able to address any concerns you may have.
You will also be seen by the anaesthetist to talk to you about the anaesthetic that will be given. The procedure is normally done under general anaesthetic, where you are put to sleep. If you have any further questions about this, please do not hesitate to ask.
If you have any allergies, you must let your doctor know. If you have previously reacted to intravenous contrast medium (the dye used for kidney x-rays and CT scans), then you must also tell your doctor about this.
We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with procedure, by law we must ask for your consent and will ask you to sign a Consent form. This confirms that you agree to have the procedure and understand what it involves.
The consent form is a form that both you and the operating doctor sign confirming that you have discussed the procedure and been informed of the risks/benefits/alternatives and have agreed to carry on with the interventional procedure. (You can have a copy of this form to take with you.)
Please feel free to ask any questions that you may have and, remember that even at this stage, you can decide against going ahead with the procedure if you so wish.
You will be taken into the CT scanner room and will be met with the anaesthetic team and the radiographers. You may be asked to lie on a trolley. The anaesthetist will place a cannula into a vein in your arm, so that the anaesthetic and any painkillers can be administered. You may have monitoring devices attached to your chest and finger and may be given oxygen.
After you are anaesthetised, you will not be aware of the procedure. A dose of antibiotic is usually given before we begin.
You will initially have a CT scan to plan the procedure- you will either be put on your front or your side for this. The CT will enable the interventional radiologist to identify the tumour.
The procedure is performed under sterile conditions and the interventional radiologist will wear sterile gowns and gloves. The area of your skin for the needle placement will be cleaned with a sterile cleaning solution and covered with a sterile drape. Under CT guidance, the cryoablation needles will be guided into the tumour. Once the needles are in the correct place, organs that may be at risk of injury will need to be moved out of the way. This is performed by injecting either carbon dioxide gas or saline, under CT guidance. When this is successfully performed, the tumour will then be frozen to destroy it and a small rim of normal kidney surrounding it. We can see the ice ball on CT to ensure that the entire tumour is covered and therefore destroyed. At least two cycles of freezing/thawing are normally performed.
Finally, a completion scan is performed to assess the results of treatment and to exclude any immediate complications including bleeding.
Figure 2. Image showing renal tumour in the lower pole of the kidney undergoing cryoablation with three needles. An ice ball produced by the cryoablation needles is visualised surrounding the tumour.
What happens to the tumour once it has been frozen?
The cells within the tumour are destroyed by the freezing process and so there is no need to remove the dead tissue. The body has its own mechanism to clear the dead cells away and scar tissue is what remains where the previous tumour was located. In some patients the area disappears completely in others there is residual scar tissue.
You will be aneasthetised for the procedure and therefore should not feel anything whilst the procedure is taking place. There should be minimal pain / discomfort post procedure but if you are in pain, the nurse can give you pain relief. Any post-procedural pain should reduce significantly by the next day, and if required, paracetamol should be enough to keep you comfortable.
Every patient’s situation is different, and it is not always easy to predict how complex or how straightforward the procedure will be but it will usually take between 2 and 3 hours.
After the procedure, you will be transported into the recovery area. The nurse will check your observations regularly- once you are comfortable and your observations are stable, you will be transferred to the ward and will be staying overnight.
You will have a small dressing on your back at the site the needles were placed. There are small puncture marks on the skin but no cuts or stitches.
You will have an intravenous drip in your arm throughout your stay so that we can give you fluids or medications if needed.
In recovery, you will slowly be allowed to drink water. If you can tolerate this, then on the ward you will be given something light to eat.
To be able to go home, we will need to ensure you are safe on your feet. When you get out of bed for the first time, you will have a nurse with you in case you feel faint or dizzy.
The interventional radiologist and clinical nurse specialist will then see you on the ward and will discharge you home if you are comfortable to do so. This commonly takes place on or before midday the following day. You will be given a discharge summary.
When you arrive home
Most people can go home the day after the procedure. We recommend that you take a week off work after the treatment and not perform any heavy lifting or strenuous exercise.
An outpatient appointment will be arranged for you 4 weeks after the procedure. You will have a CT scan of the kidneys and blood tests to check your kidney function. Once these tests have been reviewed you will have a telephone outpatient appointment to go over the results and you will be able to ask any further questions you may have.
Things to look out for:
- Blood in urine
- Uncontrolled pain- not controlled by Paracetamol
- Increasing fever for more than 1 week after the procedure
- Pain on breathing/worsening shortness of breath
- Swelling or bleeding at the needle insertion site.
If you have cause for concern following discharge, please contact our Clinical Nurse Specialist on 0790 467 4635 or 0797 069 9321.
If you are unable to contact our team out of hours, please contact the UCH 24-hour nurse led helpline on 0794 795 9020.
We will update your GP after your discharge, but immediately after the procedure they may not be aware of the details. If you see your GP after the treatment, please take your post discharge instructions with you.
Some of your questions should have been answered by this page but remember that this is only a starting point for discussion about your treatment with the doctors looking after you. Make sure you are satisfied that you have received enough information about the procedure.
Additional information available:
Provides information and support for kidney cancer patients and their carers.
Information on living with the practical, emotional and financial effects of cancer.
Tel Number:
Interventional Oncology Clinical Nurse Specialist: 0790 467 4635 or 07970 699 321
UCH Switchboard: 020 3456 7890
Address:
Interventional Radiology Imaging Department, University College Hospital, 2nd Floor, 235 Euston Road, London NW1 2BU
Interventional Oncology Service email: uclh.
Radiology Admin enquiries phoneline: 020 3447 3267
Website: www.
Hospital Transport Services: 020 3456 7010
Procedures:
The Imaging Department, Level 2 Podium in the main University College Hospital building with the entrance on Euston Road (see map below).
Travelling to the hospital
No car parking is available at the hospital. Street parking is limited and restricted to a maximum of 2 hours.
Please note the University College Hospital lies outside, but very close to the Central London Congestion Charging Zone.
Tube
The nearest tube stations, which are within 2 minutes’ walk, are:
- Warren Street (Northern and Victoria lines)
- Euston Square (Hammersmith & City, Circle and Metropolitan lines)
Overground trains
Euston, King Cross & St Pancras and Kings Cross Thames link railway stations are within 10-15 minutes’ walk.
Bus
Further travel information can be obtained from http://
Hospital transport service
If you need (and are eligible for) transport, please call:
020 3456 7010 (Mon to Fri 8am-8pm) to speak to a member of the Transport Assessment Booking Team.
If you have a clinical condition or mobility problem that is unlikely to improve you will be exempt from the assessment process. However, you will still need to contact the assessment team so that your transport can be booked. If your appointment is cancelled by the hospital or you cannot attend it, please call 020 7380 9757 to cancel your transport.
Services
Page last updated: 20 February 2025
Review due: 01 February 2027