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Fourth ventricular tumour - a "choroid plexus papilloma" (above collage): This young patient presented with long-standing nausea and vomiting, gradually worsening vision, new-onset uncontrolled hiccups, and impaired ability to walk. Upper-left panel: MRI shows a large solid tumour (red circle) located in the fourth ventricle (a fluid cavity of the brain). Upper-centre panel: MRI shows part of the tumour (white ovoid structure to the right of the arrow). It appears to be firmly adherent to and compressing the floor of the fourth ventricle (green arrow; where critical nerve structures lie - including those subserving facial expression, eye and tongue movement, nausea/vomiting, hearing and balance, and cardiorespiratory control). The dark area to the right of the tumour is a fluid cyst. Upper-right panel: Intraoperative image shows the exposed solid tumour being debulked using a "precision-tip" ultrasonic aspirator (blue arrow head). Lower-left panel is an intraoperative photograph that shows the tumour very adherent to the floor of the fourth ventricle in the region of the human nausea/vomiting centre (obex/area postrema), requiring meticulous dissection using a very fine pair of "microscissors" in order to preserve the local brainstem critical fiber tracts and nuclei. Lower-centre panel is a postoperative MRI scan showing complete removal of the tumour (previously in the area marked by the red circle). Lower-right panel is another postoperative MRI scan of this patient showing that the previously compressed and displaced brainstem region now lies preserved and free of any tumour. The fluid cyst to the right of the tumour is now collapsed as desired. The patient made an excellent postoperative recovery and was independent and ambulating well within 72 hours of surgery.

Petroclival tumour - a "ruptured dermoid" (above collage): This young patient presented with new headache and disturbance of sensation along one side of the body. Upper-left panel: MRI shows part of the tumour (red circle). Note the close proximity of the tumour to the upper brainstem around which the tumour wraps (red arrow head). Upper-centre panel: MRI shows some interesting parts of the tumour (red circle). It projects a tongue that wraps around one side of the brainstem (green arrow) and displaces and compresses the brainstem here. Delicate nerves for eye movement (cranial nerves 3 and 4) pass in this compressed corridor, as do critical blood vessels such as the posterior cerebral artery, none of which can be injured during removal of the mass. Upper-right panel: Intraoperative image shows the soft, white cheese-like tumour (blue arrow head) exposed and being aspirated. Surgery was carried out through a "modified pterional transSylvian and medial subtemporal" surgical approach. Lower-left panel is an intraoperative photograph that shows part of the tumour cavity following removal of tumour from around the brainstem. In this region the tiny "whisp-like" perforatong arteries that nourish the brainstem are preserved (blue arrow heads). Lower-centre panel is a postoperative MRI scan showing complete removal of the tumour. The tumour was previously located in the area encompassed by the red dotted circle. The brainstem portion of the tumour (red arrow head) is also no longer present as intended. Lower-right panel is another postoperative MRI scan of this patient showing no residual tumour. Some blood products and haemostatic fabric are present as expected in the cavity of the medial temporal lobe from which an additional knuckle of tumour was also extracted. The man has no neurological impairment and returned to his University studies.

Recurrent aggressive brain tumour - a "glioblastoma multiforme" or GBM/grade 4 of 4 astrocytoma (above collage): This middle-age patient's primary brain cancer, with its expected aggressive biology, recurred several months after his first operation and following both oral chemotherapy and radiation therapy. Despite the radiological "recurrence", the patient was fully neurologically intact and functionally independent. In order to preserve his expected quality and quantity of life, repeat surgery, this time with the patient "awake" and for planned implantation of chemotherapy (Gliadel) wafers, was advised by Dr Khurana. Upper-left panel: MRI shows part of the tumour (red circle). The brain of the patient's right temporal lobe is swollen and likely infiltrated by fingers of tumour (red arrow heads). Upper-centre panel: MRI shows part of this solid tumour. Upper-right panel: Intraoperative image shows the tumour being removed. The tumour is quite engorged with proliferating blood vessels, and parts of it have the expected greyish hue (blue arrow head). Lower-left panel is an intraoperative photograph showing light-coloured Gliadel chemotherapy "wafers" (blue arrow heads) being placed in the cavity of the tumour after the tumour has been debulked. Disposable green forceps are used to place these disc-shaped structures that deliver the chemotherapy directly to the part of the brain that needs it most. The chemotherapy can penetrate somewhere between 10-20 mm beyond the cavity walls, thereby targeting surrounding cancer cells/fingers that reach beyond the main tumour mass that has just been removed by the surgeon. The tip of this device is only a few millimetres in size. Lower-centre panel is a postoperative MRI scan showing macroscopic removal of the tumour (cavity in red circle), and the dark shadows of the chemotherapy wafers also noted here (green arrow). Lower-right panel is another postoperative MRI scan of this patient showing the chemotherapy wafers in the surgical cavity (green arrow). The patient tolerated the awake surgery and the wafer placement very well, and continues to remain neurologically intact. He will be rescanned periodically as required for such brain cancers.

Skull base meningioma (above collage): This patient was found to have an extensive meningioma surrounding or displacing several critical cranial nerves and blood vessels at the base of her skull. Upper-left panel: MRI shows part of the tumour (red circle). Note the close proximity of the tumour to the upper brainstem (bst) and surrounding anterior and middle cerebral arteries (light blue arrows). Upper-centre panel: MRI shows part of the tumour (Tu) and the immediately adjacent and gradually encased nerves for vision (optic apparatus; yellow arrow heads) and internal carotid arteries (indicated by the white lines on either side of midline). Upper-right panel: Intraoperative image shows the tumour (Tu) being exposed. Note the immediately adjacent optic nerve (yellow arrow head) which was bowed by the tumour. Lower-left panel is an intraoperative photograph that shows the tumour being removed by a special device known as an ultrasonic aspirator (CUSA). The tip of this device is only a few millimetres in size. Lower-centre panel is a postoperative MRI scan showing complete removal of the tumour without any neurological complication. The tumour was previously located in the area encompassed by the red dotted circle. The brainstem (bst) lies immediately behind this region. The major arteries of this region (white in this panel) are all preserved. Lower-right panel is another postoperative MRI scan showing that the previously compressed and displaced optic apparatus (yellow arrow heads) now lies preserved and free of any tumour. The pituitary gland and its stalk (green arrow head) are intact and functioning normally postoperatively. The patient was back at work not long after surgery.

Brain bypass (above collage): The above four images are from a complex and successful brain bypass procedure carried out by Dr Khurana and his colleagues. For further information regarding the concept and procedure of brain bypass, and for an explanation of the above images, please visit the brain bypass page of our partner educational Site:

www.brain-aneurysm.com

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