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Brain ablation in the rat cerebral cortex using a tunable‐free electron laser
Author(s) -
OvelmenLevitt Janice,
Straub Karl D.,
Hauger Suzanne,
Szarmes Eric,
Madey John,
Pearlstein Robert D.,
Nashold Blaine S.
Publication year - 2003
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.10197
Subject(s) - laser , ablation , wavelength , absorbance , photoablation , infrared , free electron laser , materials science , optics , laser ablation , chemistry , microsecond , optoelectronics , physics , medicine , excimer laser
Background and Objectives We used the MARK III free electron laser (FEL) tuned to molecular vibrational absorbance maxima in the infrared (IR) wavelength range of 3.0–6.45 μm to study the effect of these various wavelengths and a power level of 5 mJ/2 microseconds macropulse on photoablation of CNS tissue. Study Design/Materials and Methods Laser lesions were produced in the parietal cortex of anesthetized rats using thermal confined mid‐IR (infrared) laser pulses tuned to the ‐OH, ‐CH, amide 1, and amide 2 absorbance bands. Histological assessments following recovery periods of 4 hours, 4 days, and 3 weeks were performed to determine the size, shape, and character of the photoablative lesions. Cell density studies were done in adjacent edematous tissue. Results Significant differences in lesion size and shape were observed as a function of wavelength. Although maximum ablation and collateral damage seemed to coincide with spectral peaks in the mid‐IR, area and depth/width ratios did not. Conclusions It was found in these experiments that wavelengths in the mid‐IR could be selected for optimal ablative properties. Using tunable, high‐peak‐power pulsed lasers, it will be possible to produce well‐defined photoablative lesions that conform to small, irregularly shaped neurosurgical targets. Lasers Surg. Med. 33:81–92, 2003. © 2003 Wiley‐Liss, Inc.