The common risk in neurosurgical procedure if occurrence of neurological deficit, bleeding during surgery, oedema due to retraction of the brain tissue, CSF leak, surgical site infection, inadequate decompression of the tumour, brain herniation, etc.
A proper preoperative surgical planning is an important step for risk mitigation.
So, risk mitigation starts with initial clinical work up of the patient. Identification of the co-morbid conditions like diabetes, hypertension, ischemic heart disease, hypothyroidism, endocrinopathy, is the priority of both anesthetist and neurosurgeon. Many co-morbid conditions are not even known to the patient. For example a patient with pituitary tumour may have visual deficits, hemianopia, hypothyroidism, diabetes insipidus of which patient may not be aware. Similarly, patients with brain metastasis may have systemic cancer which remains undetected.
All exigencies must be considered by a neurosurgeon before operating. For example, during surgery of the spinal cord there is chance of CSF leak. So, dural repair with artificial dura and its reinforcement with fibrin glue must be considered prior to surgery.
In neurosurgery nothing is unexpected. All the steps are well planned. It is like standard operating procedure. It is like checklist of each neurosurgical procedure.
Prevention and reduction of infection in surgery was possible by introduction of antiseptic principles described by Joseph Lister in 1867. So, the antisepsis must be maintained in operation theatre and also during any invasive procedure in any neurosurgical patient. The use of prophylactic antibiotic significantly reduces the risk of infection in a neurosurgical patient. Part preparation should be done properly and enough time to be given for part preparation. It is surgeon's responsibility to ensure that all staff involved in surgical procedure adheres to the set principles of antisepsis.
The patients of intracranial brain lesions often present with seizures. Some patients with brain tumours do not present with seizures but are very much likely to develop epilepsy, especially patients with lesions in basifrontal region, at rectus gyrus after surgery. Meningiomas are also epileptogenic. In such patients prophylactic anti epileptic drug be started.
Some intracranial brain lesions have associated vasogenic oedema. So, in high grade gliomas or meningiomas, steroid ( Dexamethasone) to be started before neurosurgical procedure to avoid sudden increase in oedema and any chance of brain herniation.
Sometimes, during surgery, intraoperative Mannitol is given to reduce intracranial pressure.
Blood loss is a risk during a neurosurgical procedure. So, to reduce blood loss during surgery head end elevation is done during surgery. It reduces intracranial procedure. Enough blood is arranged before surgery depending upon the procedure.
All neurosurgical procedures are designed in such a manner that there should be minimal retraction of the brain. It reduces need for retraction of the brain and any possibility of post operative edema and subsequent brain schema or brain herniation. It is the basis principle of practising skull base surgical approaches.
Surgical approach to the lesion is always through non-eloquent area of the brain. So, there is immense significance of surface marking and pre-operative surgical planning. Most of the intraparenchymal frontal lobes lesions like frontal lobe gliomas are approached through right middle frontal gyrus just anterior to the coronal suture. Similarly, posteriorly placed intraparenchymal parietal lobe lesions are approached through right sided superior parietal lobe. It is very common practice that ventricular end of the ventriculo-peritonal surgery is introduced either through right middle frontal gyrus just anterior to the coronal suture or through the right superior parietal lobule. The endoscopic third ventriculostomy (ETV) is also done through right middle frontal gyrus by making a bur hole just anterior to the coronal suture in the mid pupillary line.
While planning excision of the cerebral convexity meningioma, the arrangement should be made for dural repair if it involves excision of the tumour along with involved dura.
Since microneurosurgery involves working through narrow surgical corridors a rigid head fixation is essential in order to maintain the desired head position and also even slight head movement may cause damage. So, either Mayfield's head-holder system or Sugita head-holder is used in such neurosurgical procedures.
Operating surgical chair is to used by neurosurgeon to avoid fatigue and tremors during surgery for better control of cautery, microscope, endoscope, drill, etc.
Neurosurgeon should be the first person to reach the operation theatre and be the last person to leave the operation theatre (If best outcome is expected). never outsource the position of the patient on operation table, marking of the incision, corticectomy to the subordinate. If not sure from the beginning, it will definitely haunt him during the entire neurosurgical procedure. Only after extubation and seeing the expected neurological outcome immediately at the end of neurosurgery ensures homeostasis of any neurosurgical procedure. Only then neurosurgeon becomes sure that operation was done perfectly. It looks a very tough task to spend so much time in surgery and also spending much more time than any body else in your team, but it is true. It must be practised without any exception. It is for perfection. Nobody is perfect but in pursuit of perfection you achieve excellence.
During spinal surgery bone nibbler is used . it should be used carefully as it may cause damage to the spinal cord. It should just nibble. Don't rotate or tear anything. Don't pull any structure unnecessarily. Use Kerrison ronguers of appropriate numbers, for nibbling small parts of the lamina.
All neurosurgeons are well versed with brain and spinal surgery. Only difference is the expertise in extent excision of the lesion without causing any complication or neurological deficit in a neurosurgical patient. So, risk mitigation is the most important task of neurosurgeon.
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