COCHLEAR IMPLANT SOFT SURGERY - FACT OR FANTASY

A basic surgical principle is to be as gentle as possible to accomplis h the goals of the operation. The concept of ''soft surgery'' for coch lear implants consisted of a small, localized cochleostomy and gentle electrode insertion, the hope being that by limiting damage to the inn er ear, superior hearing results might be obtained. The technique incl udes deferring the cochleostomy until immediately before electrode ins ertion, use of a large burr to flatten the promontory, followed by a s maller burr to expose the endosteum, preservation of the endosteum of the scala tympani, smoothing of the bony edges with burrs and dissecto rs, limited opening of the scala tympani, no suctioning of perilymph, gentle electrode insertion, and potential use of a lubricant to facili tate insertion. Although this technique has a theoretic basis, is esth etically satisfying, and has been used in many cases involving the Nuc leus device at multiple centers, no data are available that demonstrat e its advantages. Furthermore, the Clarion device, the results of whic h seem to be comparable to those of the Nucleus device, requires much more extensive and potentially damaging surgery, The pros and cons of soft surgery will be discussed. Although soft surgery seems desirable to limit trauma within the cochlea, other factors such as full electro de insertion, stimulation strategy, and survival of ganglion cells may be more important predictors of successful results.