Selective catheterization of the inferior petrosal sinuses: new catheter design. Catheters for selective catheterization of the right and left inferior petrosal sinuses have been developed to replace the complex tip-deflector catheter-guide-wire system currently used. The new catheters are easily formed from commonly available straight catheters with the use of steam. They have been successfully tested in 22 patients; the only complications were minor groin hematomas. 