| abstract |
A medical electrical lead having a fixation helix which is surface treated along at least a portion to have a relatively high microscopic area along with a relatively low macroscopic area. In the preferred embodiment, such a surface treated portion is accomplished with a porous platinized construction. The surface treated portion further has a bioabsorbable coating in order to permit the helix to be inserted into the heart tissue without causing damage to the heart tissue through the engagement of the surface treated portion with heart tissue during insertion. In the preferred embodiment the bioabsorbable material is mannitol, although other bioabsorbable materials may also be used, such as a material which is no more than sparingly soluble in water, for example, the steroid beclomethasone dipropionate anhydrous. Through such a construction the helix may be inserted into tissue while the coating of absorbable materials provides a smooth surface between the surface treated portion of the helix and the tissue. Once inserted, the coating is absorbed and the surface treated portion provides electrical contact with the heart tissue. |