44-6 THE PINEAL ORGAN 



pillow. With the depletion of cerebrospinal fluid during the operation, 

 it is necessary to balance this by an adequate intake, and therefore after 

 the operation a continuous rectal saline infusion is instituted. A purge 

 is given on the second day after operation, and if there is much headache 

 a lumbar operation is performed. The stitches are removed on the tenth 

 day, and the patient is subsequently allowed to get out of bed. 



2. Van Wagenen's Operation.— The second method of surgical 

 approach is that devised by van Wagenen, in which the tumour is attacked 



Fig. 296. — Section through 

 the Brain showing the 

 Exposure and Incision 

 of the Corpus Callo- 



SUM. 



Fig. 297.- 



-The Actual Removal of a Pineal 



Tumour. 



through the median wall of the lateral ventricle. It is an easier method 

 and the route is less vascular, and the tributaries of the great vein of 

 Galen can be more easily seen and dealt with. The disadvantage, how- 

 ever, is that it leaves some permanent disturbance of function in the form 

 of hemiplegia and homonymous hemianopia. 



The first part of the operation is very similar to Dandy's approach — 

 an osteoplastic flap is fashioned and turned outwards (Fig. 298). The 

 dura mater is incised and a flap turned downwards. A reversed L-shaped 

 incision about 6 cm. in length is made in the cortex, extending from the 

 posterior end of the superior temporal lobe gyrus upward and slightly 

 backward, ending in the lobus parietalis superioris. This incision is 



