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The Faculty has been a leading force in promoting the multi-disciplinary management of the patient with chronic and cancer pain. Still, as the Palliative Care Physician, Dr Odette Spruyt, noted at the recent Australian Pain Society meeting, there still exists clinical barriers that limit the full range of clinical skills available to improve the care of patients with cancer pain. Today we might review the place of neurosurgery in the management of the cancer pain patient.

Fifty years ago, the neurosurgeon played a dominant role in these cases. This can be identified in the two text books written by White & Sweet in Boston in the 50's and 60's. They list long case studies involving timely ablative surgery. While many of the procedures have been discarded, some have proved most effective in cancer pain patients.

When I first commenced neurosurgery in the 60's, the neurosurgeons offered a range of procedures in the management of cancer pain. Bill Nordenboss (on the right), in Amsterdam, was one of the outstanding leaders in this area.

Mark Sindou (on the left), in Lyons, and others such as Herbert Rosomoff, John Chiu, Ted Hitchcock and John Loesser were other major contributors.

Today, the excellent textbook by Professor Kim Burchiel, from Portland USA, is probably the most comprehensive and reliable reference book on surgical interventions.

Today, our understanding of cancer pain has come a long way thanks to the research from the International Association for the Study of Pain and  also to our own epidemiologists such as Fiona Blyth. The recent meta analysis of English and Dutch papers showed the prevalence of cancer pain was 50%, rising to 75% in the late stages, while 33% of survivors of cancer suffered pain. The challenge now is to improve the care of these patients.

The progress of these patients can be clinically confusing at times. This may be due to:-

•    Tolerance to the available narcotic drugs;
•    Progression and spread of the malignancy;
•    Complications due to treatment of the malignancy such as brachial neuritis following radiotherapy;
•    Independent medical conditions can arise, for example, a cervical disc protrusion;
•    Lastly, drug addiction may complicate the presentation.

In all cases, the multi-disciplinary team will need to consider the treatment priorities which may be:

• Appropriate narcotics
• Chemotherapy
• Radiotherapy
• Psychological support
• Physiotherapy
• Spiritual support
• Surgery
• Palliative care.

Surgical procedures can be considered under three headings - Anatomical, Augmentative and Ablative.

In the case of anatomical approaches, the sarcoma of the femur, head and neck cancer or the vertebral tumour can be removed with pain relief.

Over the past twenty years, augmentative procedures, particularly using intrathecal narcotics delivered through a Medtronic pump or through an intraventricular reservoir, have proved to be very a popular and invaluable procedure particularly for pain that is in the midline, such as pancreatic cancer, pelvic cancer and diffuse prostatic cancers and breast cancers.

While these pumps were exceedingly expensive and often unavailable in the public hospital system, they took attention away from the surgical ablative procedures. Nevertheless, they were not always effective or tolerated. They required revision and this could cause blunting of the patient's cognitive function.

The writings of White and Sweet, and more recently Burchiel, have identified a range of neurosurgical procedures that could be carried out at all levels of the anatomical pain pathways to relieve cancer pain. This diagram shows the potential sites that transection of the pain pathways can be carried out and they include:

• Neurectomies - peripheral and cranial
• Rhizotomies
• Myelinotomies
• Cordotomies
• Medullary tractotomies
• Thalamotomies
• Cingulotomies
• Cortical resections
• Pituitary ablation.

Often the MRI (above) will show the tracking. Increasingly the early identification and recognition of this potential has helped in the management of these threatening lesions.

We can remove the nerve through a transmaxillary approach to the gasserian ganglion or we can approach through a small craniotomy in the posterior fossa and section the 5th or, at times, the 9th glossopharyngeal nerve at the brainstem.

The relief of pain and the effectiveness of the procedure are most satisfying but an early intervention as soon as facial numbness becomes evident is indicated.  

The other ablative procedure which I consider still has a place in modern cancer care if the cordotomy. This was initially described by Spiller and Martin in 1912. Technically it could be carried out in the thoracic spine or the cervical spine. Under a general anaesthetic, the spino-thalamic pathway was identified in the anterolateral aspect of the spinal cord on the contralateral side to the pain.
 
Using a fine scalpel, the anterior cord, to a depth of 4.5 millimetres, was sectioned. The procedure took about ninety minutes. It was improved using the operating microscope but it was not recommended for bilateral or midline pain and as we began to learn more and more about chronic pain, it was not appropriate for persistent pain due to non-malignant conditions.

This slide identifies the configuration of the body in this area which covered 70% of the spino-thalamic nerve fibres.

The indications for a cordotomy included unilateral severe pain which had failed to respond to medications in a patient who was suitable for anaesthesia and in a patient whose quality of life and length of life required multi-disciplinary assessment prior to proceeding with this operation.

A more attractive approach was developed by an old friend, Professor Sean Mullan in Chicago, in 1963. He was one of the most innovative neurosurgeons of the 20th Century.

He devised a percutaneous procedure in which an insulated needle was passed through the cervical muscles from a lateral point through the dura and through the pia into this anatomical path of the anterior cervical spinal cord.

The patient was positioned supine. The anaesthetic was a Neurolept. The image intensifier was used for localisation and the radiofrequency lesion generator was required. The patient's head was held in a fixed headrest and a needle was introduced subcutaneously.

Under image control and with the needle held in the guide, it was passed into the spinal cord to allow coagulation of the anterolateral quadrant of the cord.

This woman had a fungating cancer of the breast causing severe pain in her shoulder and upper trunk. She underwent the percutaneous procedure with a successful result and a localised loss of pain in the upper limb and chest.

This shows the area of pain and sensory loss over the areas of the upper limb and trunk and covering the breast resulting from the percutaneous cordotomy.

Rosimoff's results for cordotomy revealed a 90% success rate at one month and a 40% of cases still have pain relief at twenty-four months. This equates well with the expected reduction in pain from most of the narcotic drugs. In most of these, the numbers needed to treat are considered to be successful if the pain is relieved by 30-50%. This applies to cordotomies at twenty-four months and cordotomies are much more effective in the first year. 

Conclusion:

The pendulum has swung too far. There remains a place for ablative surgery in cancer pain.

The surgeon continues to have some part to play in the management of cancer pain through surgical procedures that are anatomical, ablative or augmentative. Aggressive anatomical procedures are becoming more effective and more successful while the general swing to augmentative procedures such as intrathecal narcotics has discounted the role of the neurosurgeon in cancer pain management.

I would suggest that neurectomies, particularly for the 5th and 9th cranial nerves, and cordotomies, are two procedures that you might reconsider.