TEST FOR PATENCY OF VENTRICULOVASCULAR SHUNT FOR HYDROCEPHALUS WITH RADIOACTIVE IODINATED SERUM ALBUMIN.

TnOUGH the presence of a " p u m p " often makes it easy to determine if a ventr iculovascular shun t is funct ioning, there are occasions when there is some doub t as to its function. Tests of the pa t ency of the valve sys tem i n vivo have therefore been under taken, using radioact ive iodinated serum albumin (RISA) . BelF injected R I S A into the ventr icular sys tem in 30 adults, and followed the passage of the radioact ive material in the tubing of ventr iculoperi toncal shunts, using a Geiger counter. The abs t rac t of Schlesinger et al. s deals with much the same type of s tudy, bu t details have no t ye t appeared. Atkinson and Fo l t z ' (p. 165) have also used R I S A in test ing pa tency of the shun t : " . . . the levels in blood are very helpful if a sudden surge of isotope ac t iv i ty can be picked up to indicate funct ioning of the shun t . " This me thod appeared to depend on the t ime of sampling and the rate of flow in the shunt , and was apparen t ly considered secondary to the determinat ion of clearance of the isotope in ventr icular fluid over a period of ~4 hours. Migliore et al. 7 have used a technic similar to t h a t described in the present investigation, injecting 50-~00 uc. of R I S A into the lateral ventricle, and sanlpiing radioac t iv i ty of blood and radioac t iv i ty of residual cerebrospinal fluid. Specific technical details were no t given in this brief clinical note.