Physical characteristics of various lasers used in stapes surgery

The invention of modern small-fenestra stapedotomy procedures using a piston-type prosthesis resulted in a remarkable hearing improvement and at the same time in a reduction of complications compared to conventionally performed stapedectomies. These procedures, however, still contain unpredictable risks such as uncontrolled stapes fracturing, luxation of the stapes or creating a floating footplate, which all can cause hearing loss or even deafness. The worldwide use of the small-fenestration techniques led to the observation that most cases of sensorineural hearing loss occurring after surgery were due to intraoperative trauma to the inner ear, most commonly during footplate manipulation. This led to the use of lasers in otological surgery as a possible tool for precise noncontact cutting of bone without any drill vibration. Today, argon, KTP, CO(2) and Er:YAG lasers are clinically used in middle ear surgery. Each laser has its characteristic interaction process with bone with its specific advantages and disadvantages. Therefore, it is not surprising that there are conflicting and controversially discussed experimental and clinical reports. The purpose of this study was to comprehensively compare the physical processes underlying the laser-tissue interaction of the different laser systems in view of safety and efficacy in order to enhance the ability to perform safe minimally invasive surgery on the stapes footplate.