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Saddle neurolytic block

What is a saddle neurolytic block for pain relief?

Pain control through a saddle block means introducing a chemical (phenol/alcohol/glycerol) through a needle into the spinal fluid and to numb the nerve fibres that carry pain sensation to your brain.

When is a saddle block used to control pain?

A saddle block is used to control cancer related pain in your perineal region (area between your legs) when the pain is difficult to control with strong pain medications. It is particularly useful when you can’t sit because of pain. Saddle blocks have been used for many years. This injection is usually one off and the effect can last for a number of weeks or even months. It can be easily repeated if required.

How is a saddle block carried out?

  • A saddle block will be carried out in operating theatre at The Walton Centre, which is on site with Aintree Hospitals and Woodlands Hospice. Only in rare cases if transfer to theatre at The Walton Centre is not possible, it can be carried out at the Woodlands Hospice Inpatient Unit.
  • You should be able to sit up for 20 minutes to facilitate your doctor to perform this block.
  • The skin on your back will be cleaned with antiseptic and then numbed to decrease feeling and pain with local anaesthetic.
  • A spinal needle is then inserted in between two bones in your back.
  • The chemical (phenol/glycerol/alcohol) will be injected through the needle into the spinal canal.
  • Once the chemical has been injected the needle will be removed and you will be asked to lean back at an angle of 45 degree for 30 minutes. This is to allow the chemical to get to the correct nerves and preserve other nervous structures.
  • You will then be taken to the recovery area.
  • Afterwards you are sent back to Woodlands Hospice by ambulance or may be discharged home or kept overnight at The Walton Centre depending on your referral. Your pain killers may be adjusted following a successful procedure.

All medicine and procedures has some risks and side effects. For saddle blocks the risks are relatively small:

  • You may get bleeding into the spine and it is rare to cause spinal compression requiring surgery.
  • You may get a headache following the insertion of the spinal needle. This usually subsides after a few days.
  • There is a high chance you may feel numb underneath. This can improve over time, but may be permanent.
  • There is a small risk to affect bladder control function. This may result in incontinence of urine and need for a urinary catheter.
  • There is a small risk to affect bowel control function. This may result in incontinence of faeces.
  • There is a very small risk of causing paralysis. This may be temporary or permanent.

You may develop new pain after this procedure for reasons poorly understood; this may be related to your condition progressing or due to unknown mechanism related to this injection even if the injection was carried out in correct manner.

Post injection care

You will be followed up by your treating consultant in close liaison with palliative medicine team. Please contact us if you have any issues after this injection.

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