Polychromatic Surgical Laser Spares Healthy Tissues

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The Phoenix™ laser is designed to overcome the deficiencies of current surgical lasers for minimally invasive removal of diseased tissues such as those associated with lower urinary tract symptoms (BPH) and other diseased tissues that are readily accessible via existing body openings and small laparoscopic incisions. Lasers are favored in many surgeries for precision and minimal blood loss yet, where large masses of tissue must be removed, lasers slower than alternative techniques and lose precision as power in ramped to improve surgical speed.

Green lasers serve as a case in point. Around the turn of the millennium, 80W lasers at 532nm proved effective in vaporizing hyperplastic prostate tissues with much lower rates of post-surgical incontinence and impotence, but surgery took much longer than the lower cost electrocautery method (TURP). The laser power was increased to 120W in 2006 and then to 180 W in 2011. The speed of tissue removal (by vaporization) improved by about 50% (80W vs. 180W) but complications rates increased substantially, mirroring TURP.

High power thulium lasers (2000nm, strongly absorbed by water in tissue) delivering up to 250W have gained popularity for their TURP-like speed, but complication rates are also similar. Theorizing that surgical complications are a function of indiscriminant tissue death known as coagulation it was recognized that the 532nm laser lost surgical precision above 80W -- where surgical effects were primarily driven by oxyhemoglobin absorption within highly vascular prostate tissue – because 80W effectively destroyed all the oxyhemoglobin that was available within the illuminated tissue volume. The additional 532nm light of higher power green lasers was scattered and absorbed indiscriminately by char: carbonized tissue that was purposefully produced to heighten the laser-to-tissue interaction beyond oxyhemoglobin absorption.

The Phoenix laser is designed to extend tissue specific absorption and prevent indiscriminant absorption by targeting multiple chromophores within target tissues, with the appropriate wavelengths for maximum absorption, while also targeting tissue breakdown and recombination products. For prostate tissue, wavelengths in the range of about 360nm to 460nm target hemoglobin, oxyhemoglobin, hemoglobin that binds combustion products such as carbon monoxide, carbon dioxide and cyanide, heme porphyrins, semen components, collagen, elastin, melanin, etc. and Amadori products of Milliard reaction chemistry (browning of meats) to vaporize these char precursors before they can continue “cooking” to carbon.

The polychromatic laser is produced by combining different colors of low power

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  • Name:
    Stephen Griffin
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