A simple method of surface marking of brain tumour

One of the most important step in achieving very good results in neurosurgery is the ability to correctly mark the tumour position on scalp of a given patient. Not every time an image guidance or stereotactic frame based precision is needed. If sagittal MR cuts or CT rescostruction is available a high degree of precision can be achieved based on these images only. Consider this example- follow simple steps to make a precise craniotomy- 1. Fix the head after patient has been put under GA. Mayfield clamp or Sugita clamp are OK. If no clamp, use a 4 inch bandage to stabilise head to the head end of table by wrapping it around protecting nose and orbits by covering them with thick cotton pad. Strict supine position with head end elevated by 30 degree should be good enough. 2.Take a silk thread and by using scale on sagittal CT cut, the distance of tumour from nasion can be precisely marked. Both anterior margin and posterior margins of tumour should be parked on scalp. The distance from midline to lateral margin of tumour is similarily marked. In this case the anterior margin of tumour to nasion is about 9cm. 3. Mark a scalp incision as an anterior to posterior linear one or a curvilinear one. I made a midline incision going little beyond marked anterior and posterior margin of tumour. Karam Chand scalp retractor is very helpful to obtain good skull exposure. 4. A free bone flap across midline, more on right side was raised by cutting skull from outside to inside by a speed drill small burr. By making a deep groove all around the outside to inside cutting helps in achieving haemostasis by applying bone wax at each stage. The final bone cut is made with chisel which can help you in achieving bevelled edges. No burr hole is made,so entire bone flap can be replaced. 5. As soon as bone flap is raised, exposed sagittal sinus is covered with gelfoam and guaze. Dural arteries are underrun with ligatres.

 6. Total tumour excision- Simpson grade 1 was achieved.