Much of surgery consists of intuitive decision making. This, in part, explains why patients seek out experienced surgeons. It is hoped that neurosurgical experience, be it personal, from reading or researching, or from observing others, creates a rich frame of reference to draw upon when making both clinical decisions and fine hand movements when manipulating someone’s brain or spine during an operation – or reacting to the unexpected.
I have an interest in surgical education and there is a particular scientific literature on the amount of experience and cognitive processing of it required to transition from novice to expert which is quite intriguing. It’s often oversimplified to 10,000 hours – which is probably the clinical experience gained in a good British neurosurgical training programme, although no high quality studies have been done either to confirm this or the validity of the many tick box exercises that UK neurosurgical trainees now have to go through.
I recently published a paper looking at clinical outcomes of surgery for spinal ependymoma, a particular type of common spinal tumour occurring intradurally (inside the dura mater lining the spinal cord and spinal nerves) and arising from ependymal cells that line the internal fluid spaces of the spinal cord.
As a study of 61 patients with spinal ependymoma, it is one of the largest single centre studies published. We confirmed what many surgeons suspect intuitively – the more tumour that is removed, the better the patient’s outcome, both in terms of survival and improvement in leg power and function.
On deeper analysis, the finding is not quite as intuitive as it sounds because the tumour surgeon’s dilemma is whether removing the last remnants of a tumour might damage normal functional neural tissue and cause a new deficit. This is a particular challenge in eloquent brain tumour surgery and numerous tools from special dyes and awake surgery to intra-operative stimulation, electrical monitoring and transcranial magnetic stimulation have been introduced to assist resections.
The message is that careful and diligent gross, total resection of intradural spinal tumours remains desirable for best outcomes. This is something that I endeavour to do in my practice as a neurosurgeon and complex spinal surgeon. Transient, and unfortunately permanent, weakness remain risks of surgery on spinal tumours, but in my experience aggressive surgical resection confers best outcome.