Viability of human septal cartilage after 1.45 microm diode laser irradiation.
OBJECTIVE
Chondrocyte viability following laser irradiation and reshaping has not been established for human nasal septal cartilage. Knowledge of the relationship between thermal injury and laser dosimetry is needed in order to optimize septal laser cartilage reshaping. The objective of this study was to determine the depth and width of thermal injury in human septal cartilage following laser irradiation.


METHODS
Excess fresh nasal septal cartilage sections from rhinoplasty or septoplasty operations were irradiated using a 1.45 microm diode laser 1.25-3.6 W (2.8 mm spot diameter) with 1 second fixed exposure time, and then at exposure times of 1-4 seconds for a fixed power of 1.25 W. An infrared camera recorded surface temperature profiles during irradiation, and the temperature data were incorporated into a rate process model to numerically estimate thermal damage. Calcein AM and ethidium homodimer-1 fluorescent dyes combined with confocal laser microscopy (CLM) were used to measure thermal damage.


RESULTS
CLM demonstrated clear demarcation between dead and living cells following irradiation. The extent of non-viable chondrocyte distributions increased with power and exposure time. The maximum depths of injury were 1,012 and 1,372 microm after 3.6 W 1 second and 1.25 W 4 seconds irradiation respectively. The damage predictions made by the rate process model underestimated thermal injury when compared with CLM measurements.


CONCLUSIONS
The assay system identified regions of non-viable chondrocytes in human septal cartilage and defined how thermal injury varies with dosimetry when using a 1.45 microm diode laser.
Choi
Ick-Soo
IS
Department of Otolaryngology, Head and Neck Surgery, Seoul Paik Hospital, Inje University, 5 Mareunnae Gil, Jung Gu, Seoul 100032, Korea. cisoo99@yahoo.co.kr
Chae
Yong-Seok
YS
Zemek
Allison
A
Protsenko
Dmitry E
DE
Wong
Brian
B
D006801:Humans; D054023:Lasers, Semiconductor; D055171:Nasal Cartilages / Q000528:radiation effects*; D014022:Tissue Survival
Lasers Surg Med. 2006 Aug;38(7):659-62; discussion 658
16799999
IEEE Trans Biomed Eng. 1998 Oct;45(10):1234-40
9775537
J Bone Joint Surg Am. 2001 Apr;83(4):566-71
11315786
J Biomed Opt. 2006 Nov-Dec;11(6):064028
17212551
Lasers Surg Med. 2007 Jun;39(5):451-7
17565732
Laryngoscope. 2006 Oct;116(10):1730-4
17003728
Biomed Eng Online. 2008 Feb 29;7:10
18312643
Appl Opt. 1993 May 1;32(13):2447-54
20820404
Arthroscopy. 2001 Feb;17(2):117-23
11172239
Am J Rhinol. 2001 Mar-Apr;15(2):109-16
11345149
Lasers Surg Med. 2003;32(1):3-9
12516064
Lasers Med Sci. 2001;16(4):284-90
11702634
J Biomed Opt. 2007 Jan-Feb;12(1):014031
17343506
Arch Facial Plast Surg. 2006 Mar-Apr;8(2):105-16
16549737
Lasers Surg Med. 2004;34(4):315-22
15083492
Med Phys. 2007 May;34(5):1828-41
17555264
Lasers Surg Med. 2005 Feb;36(2):147-54
15704163
Phys Med Biol. 2003 Jan 7;48(1):19-29
12564498
Lasers Surg Med. 2001;28(5):427-34
11413554
IEEE Trans Biomed Eng. 2008 Apr;55(4):1279-90
18390319
Lasers Surg Med. 2007 Jul;39(6):494-503
17659588
Arthroscopy. 2003 Mar;19(3):310-3
12627157
Lasers Med Sci. 2008 Apr;23(2):169-77
17541813
Arthroscopy. 2000 Jul-Aug;16(5):527-36
10882450
Ann Plast Surg. 2002 Nov;49(5):527-31
12439022
Arch Facial Plast Surg. 2002 Jul-Sep;4(3):180-5
12167077
Biotechnol Genet Eng Rev. 2000;17:553-78
11255681
Phys Med Biol. 2004 Nov 7;49(21):4861-77
15584524
Lasers Surg Med. 2006 Feb;38(2):155-62
16493663
Phys Med Biol. 2005 Sep 7;50(17):4075-86
16177531
Am J Otolaryngol. 1993 Nov-Dec;14(6):410-2
8285311