The safe removal of water spray dispersed laser plume is not covered by ANSI Z136.3 Standard for Safe Use of Lasers in Health Care (2018 Edition)
June 3, 2020
This page highlights the practical aspects of learning and using LightScalpel flexible fiber CO2 lasers in every-day soft tissue laser surgeries
LightScalpel laser surgery products are FDA cleared for incision, excision, vaporization, ablation, and coagulation of soft tissue in medical specialties such as oral surgery, dentistry, plastic & reconstructive surgery, dermatology, ophthalmology, otorhinolaryngology, podiatry, gynecology, neurosurgery, urology, and general surgery.
Our American-made surgical CO2 lasers come with durable flexible fibers and ergonomic scalpel-like handpieces. Over 12,000 surgeons world-wide enjoy their many praised clinical benefits and ease of use (see bloodless laser blepharoplasty in Figure 1 and bloodless laser frenectomy in Figure 2) of flexible fiber CO2 lasers since 1991.
The wavelength of the laser and how it interacts with water (the dominant component of soft tissue) is the key to understanding how the laser light cuts soft tissue – see Figure 3:
The absorption/penetration depth in water for the LightScalpel CO2 laser wavelength (10,600 nm) is approximately 0.015 mm, which explains the very thin (less than 0.1 mm) thermal damage zone on the margins of the incision in soft tissue . Such short penetration depth enables high precision in removing the tissue, while simultaneously providing sufficient hemostasis.
In contrast, the absorption/penetration depth in water for diode laser wavelengths in the 800-1,000 nm range is a thousand times greater than for the CO2 laser wavelength. Although hemoglobin and melanin strongly absorb light in the 800-1,100 nm range, their relatively low concentrations in soft tissue result in a widely spread thermal damage zone of several mm.[2, 3] Such deep penetration of diode laser light enables many useful non-surgical applications such as hair removal, spider vein reduction, biostimulation, etc.
Erbium laser wavelengths in the 2,780-2,940 nm range are shown to be energy efficient and spatially accurate for photo-thermal ablation; however, their coagulation ability is poor. Compared to the CO2 10,600 nm wavelength, erbium lasers are 5-15 times less efficient at coagulation. The optical absorption and coagulation depths of the erbium’s wavelengths are much smaller than blood vessel diameters; this accounts for the inability of erbiums to prevent bleeding from the blood vessels severed during tissue ablation.
The ability of the CO2 laser’s 10,600 nm wavelength to vaporize water-rich soft tissue makes it a true “What You See Is What You Get” soft tissue-laser with maximum precision; its minimal collateral thermal effects are sufficient for hemostasis. The CO2 laser is THE ONLY practical soft-tissue surgical laser that uses the laser beam directly to cut, ablate and photo-thermally coagulate the soft tissue.
The LightScalpel flexible fiber CO2 laser is a soft-tissue laser scalpel that is easy and fun to use due to:
Consider a steel blade: regardless of how sharp the blade is, there will be no interaction between the blade and tissue unless mechanical pressure is applied to the blade, forcing it through the tissue surface. For a laser scalpel, the power density of the focused laser beam is equivalent to the mechanical pressure that is applied to a cold steel blade: the greater the laser power density, the greater the rate of soft tissue interaction.
Disposable-free “tipless” laser handpieces from LightScalpel are designed to closely simulate the scalpel-like experience without making any contact with the tissue. Maintaining a 1-3 mm distance between the distal end of the handpiece and the tissue (see Figure 5) is required to achieve the designated spot size.
A quality cut made by a sharp steel blade can likewise be achieved by adjusting the focal spot size of the laser beam. The smaller (or sharper) the focal spot of the beam, the narrower and the deeper the incision. Just like a dull blade, an oversized laser beam spot cannot produce a good quality incision. For laser tips, the 0.4 mm spot size is the most popular for cutting applications. For newer tipless handpieces, the best spot size for cutting is 0.25 mm.
For a rapid switch from cutting to just photo-coagulation, the laser beam can be defocused by either (1) selecting a larger spot size, or (2) simply moving the handpiece away from the tissue by 10-15 mm, and “painting” the “bleeder” for enhanced hemostasis.
Not all types of laser surgery involve incising the tissue. Superficial surface ablation is best achieved through using large beam spot size settings, such as 0.8 mm or 1.4 mm diameter.
For the most comfortable hand-speed control, while achieving the desirable incision depth or superficial ablation rate, the clinician can vary the average laser power. A thin skin incision made by a gently applied sharp blade can also be accomplished by the finest spot size of 0.25 mm and low power settings. For thicker skin incisions, a higher power setting is recommended while the 0.25 mm spot size is still appropriate. However, when debulking a large tumor, the larger 1.4 mm spot size and higher power settings are recommended for comfortable hand-speed and the most efficient completion of the laser surgery.
The SuperPulse mode (see Figure 6) is made of bursts of very high peak power laser pulses that are spaced far enough apart to allow for efficient tissue cooling between the pulses. SuperPulse minimizes the amount of heat escaping from the cutting/ablation zone to surrounding tissue; it results in less char on the margins of the cut, facilitating greater healing and reduced post-operative scarring of the surgical wounds. For a stronger hemostasis effect through photocoagulation by laser light, turning SuperPulse mode off is recommended, e.g., for procedures such as debulking of highly vascular tumor masses.