Despite many safety features, surgical microscope-induced injuries still occur and technological means to eradicate these adverse events are yet to be developed.
Illumination and magnification are the two basic concepts behind surgical microscope technology. Magnification, the primary function of the microscope, allows objects to be seen that are invisible to the naked eye. Nevertheless, magnification isn't effective in the dark. Illumination is the second critical function, shedding light on the structures within the deep and dark spaces of the body. Recent innovations in microscope technology have concentrated on improving illumination to accommodate the light intensity required for minimally invasive procedures and microsurgeries in various subspecialty areas.
As a source of energy, light generates heat.1 The deeper the surgeon reaches, the higher light intensity is needed, which generates more heat. Furthermore, the smaller the operative structure, the more magnification is needed which, in turn, requires higher light intensity and results in more heat. As light propagates through the layers of tissues, it loses intensity and heat.
The skin, as the first layer of tissue and closest to the microscope's light, is most vulnerable.2 The risk of skin injury increases with longer exposure time and shorter distance from the light source. Besides the microscope's light, the patient's tissue optical properties also play a role in the risk of skin burn. For example, an infant's thin skin or an elderly patient's fragile and dry skin is at greater risk. In addition, the patient's tissue perfusion must be considered. When circulation is compromised, the tissue's ability to dissipate heat will be reduced.
Microscope considerations
* Before the procedure, check the microscope to ensure it's in working condition and that the light protection filters are in place.
* Start the microscope with minimal light intensity and increase the intensity gradually. Avoid maximum intensity or use it for as short a time as possible.
* Minimize skin exposure by focusing the light on the area where surgery is being performed.
* Turn the illumination off as soon as it's not needed.
* Know your microscope's safety features and make sure all users have received required training.
* Schedule regular quality assurance and maintenance.
Patient considerations
* Keep the surgical incision site cool by covering the skin around the incision with wet sponges/towels, and hydrating the skin and the incision site with repeated irrigations.
* Take special precaution when treating high-risk patients such as pediatric and geriatric patients.
* Avoid injecting vasoconstrictive drugs into the surgical site. If unavoidable, use minimal amounts.
* Minimize the use of metal instruments such as ear speculum and retractors, as they tend to get hot quickly and can cause skin burn. If these devices are necessary, keep the skin protected with wet sponges and keep them moist throughout the procedure.
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