The HCA International Foundation Travelling Scholarship 2009 report: The Department of Neurosurgery, Hôpital Gui de Chauliac in Montpellier, Michael David Jenkinson, Consultant Neurosurgeon, The Walton Centre Foundation NHS Trust.
Report: The application of awake craniotomy and intra-operative functional brain mapping in glioma resection.
In February 2010 I had the opportunity to visit Professor Hugues Duffau at the Department of Neurosurgery, Hôpital Gui de Chauliac in Montpellier, France. Professor Duffau is an internationally recognised expert in the application of awake craniotomy, cortical and subcortical neurophysiological monitoring and advanced brain mapping in glioma surgery. He utilises this technique to facilitate resection of low grade gliomas located in eloquent regions of the brain. His clinical practice is now almost exclusively patients with low grade gliomas and he receives referrals not only from other neurosurgeons in France, but also from international colleagues. Since there is increasing literature evidence that extent of resection influences survival in glioma surgery and maximal safe resection is rapidly becoming the standard of care for these patients, utilising awake craniotomy and functional brain mapping ensures a safer and more extensive resection can be achieved.
I attended theatre, outpatient clinic and the neuro-oncology MDT. Professor Duffau performs 2 – 3 awake craniotomies per week for low grade gliomas. For the tumour resection he uses an asleep – awake – asleep approach and the patient’s head is secured in pins. After turning a standard craniotomy, anaesthesia is reversed and the endotracheal tube is removed. A good working relationship with the anaesthetist is essential, and smooth anaesthesia is of paramount importance to avoid patient distress and minimise the risk of intra-operative brain swelling or herniation. Once the patient is awake, a speech therapist assesses language function using a series of PowerPoint slides. The patient has to name objects and read words whilst the surgeon applies a bipolar cortical stimulation to the brain and watches for speech arrest. The area is mapped and eloquent regions are marked and avoided during the planned tumour resection. For deep-seated insular tumours, a window technique through non-eloquent cortex is used to reach the tumour. This avoids splitting the sylvian fissure and reduces the risk of vascular injury and post-operative vasospasm. In addition, Professor Duffau avoids the use of bipolar cautery as he believes this minimises the risk of vascular injury to deep perforating vessels. Pre-operative discussions focus on making the patient aware of the risks of temporary and permanent neurological deficit. Post-operatively language function is re-assessed and in those patients with neurological deficits, speech therapists provide focused rehabilitation. If the speech is preserved at the end of surgery, then with time and rehabilitation temporary deficits will resolve. The outpatient clinic provided an opportunity to meet patients who had undergone tumour resection months or years previously. The extent of resection in some cases was remarkable, and patients were functioning well with minimal or no neurological deficit. The results in the clinic truly reflect those in Professor Duffau’s published papers.
My visit to Montpellier provided a concentrated exposure to awake craniotomy and intra-operative brain mapping. On my return to the UK, I took up a Consultant post at The Walton Centre NHS Foundation Trust in Liverpool. I have performed awake tumour resections applying some of the techniques learned from Professor Duffau, in particular the use of more detailed speech assessment and the window technique through non-eloquent brain to reach deep-seated tumours. Pleasingly, to date I have not had any permanent language deficit in my patients.
In summary this was an inspiring and productive trip. I would like to thank Professor Duffau for accommodating my visit, for tolerating my poor French grammar and on insisting that he and his colleagues conduct the neuro-oncology MDT in English. Finally, I am grateful for the support of the HCA International Foundation who made this trip possible.