Evaluation of the Bending Loss of the Hollow Optical Fiber for Application of the Carbon Dioxide Laser to Endoscopic Therapy

Daisuke  Kusakari; Hisanao  Hazama; Rinna  Kawaguchi; Katsunori  Ishii; Kunio  Awazu

doi:10.4236/opj.2013.34A003

OPJ Vol.3 No.4 A , August 2013

Evaluation of the Bending Loss of the Hollow Optical Fiber for Application of the Carbon Dioxide Laser to Endoscopic Therapy

Daisuke Kusakari^*, Hisanao Hazama, Rinna Kawaguchi, Katsunori Ishii, Kunio Awazu

Abstract: Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollow optical fibers transmitting mid-infrared light have been developed, and the application of carbon dioxide laser to endoscopic therapy has become possible. However, it is expected that the irradiation effect is influenced by the change in the laser power at the tip of the hollow optical fiber due to the change in the transmittance by the bending loss. The purpose of this research is to quantitatively evaluate the change in the output power and therapeutic effect by bending the hollow optical fiber in a gastrointestinal endoscope. The change in the transmittance of the hollow optical fiber due to the insertion of the fiber into the endoscope and bending of the head of the endoscope was measured. Then, the relationship between the irradiated laser power and the incision depth for a porcine stomach was investigated. As the results, the most significant decrease in the transmittance of the hollow optical fiber was caused by the insertion of the fiber into the instrument channel of the endoscope, and bending of the head of the endoscope with the angle of 90° decreased the output laser power and incision depth by 10% and 25%, respectively. Therefore, it was confirmed that the bending loss of the hollow optical fiber due to the bending of the head of the endoscope had no significant influence on the endoscopic therapy using the carbon dioxide laser.

Keywords: Hollow Optical Fiber; Carbon Dioxide Laser; Bending Loss; Endoscopic Therapy

Cite this paper: D. Kusakari, H. Hazama, R. Kawaguchi, K. Ishii and K. Awazu, "Evaluation of the Bending Loss of the Hollow Optical Fiber for Application of the Carbon Dioxide Laser to Endoscopic Therapy," Optics and Photonics Journal, Vol. 3 No. 4, 2013, pp. 14-19. doi: 10.4236/opj.2013.34A003.

References

[1] J. T. Walsh and T. F. Deutsch, “Er:YAG Laser Ablation of Tissue: Measurement of Ablation Rates,” Lasers in Surgery and Medicine, Vol. 9, No. 4, 1989, pp. 327-337. doi:10.1002/lsm.1900090404

[2] J. T. Walsh, T. J. Flotte, R. R. Anderson and T. F. Deutsch, “Pulsed CO2 Laser Tissue Ablation: Effect of Tissue Type and Pulse Duration on Thermal Damage,” Lasers in Surgery and Medicine, Vol. 8, No. 2, 1988, pp. 108-118. doi:10.1002/lsm.1900080204

[3] K. Ishii, S. Watanabe, D. Obata, H. Hazama, Y. Morita, Y. Matsuoka, H. Kutsumi, T. Azuma and K. Awazu, “Selective Mucosal Ablation Using CO2 Laser for the Development of Novel Endoscopic Submucosal Dissection: Comparison of Continuous Wave and Nanosecond Pulsed Wave,” Proceedings of SPIE, Vol. 7562, 2010, Article ID: 75620Q. doi:10.1117/12.842426

[4] S. R. Browd, J. Zauberman, M. Karandikar, J. G. Ojemann, A. M. Avellino and R. G. Ellenbogen, “A New Fiber-Mediated Carbon Dioxide Laser Facilitates Pediatric Spinal Cord Detethering,” Journal of Neurosurgery: Pediatrics, Vol. 4, No. 3, 2009, pp. 280-284. doi:10.3171/2009.4.PEDS08349

[5] Y. Matsuura, “Basics of Optical Fibers for Medical Applications,” The Journal of Japan Society for Laser Surgery and Medicine, Vol. 31, No. 4, 2011, pp. 407-412 (in Japanese).

[6] Y. Abe, Y. W. Shi, Y. Matsuura and M. Miyagi, “Flexible Small-Bore Hollow Fibers with an Inner Polymer Coating,” Optics Letters, Vol. 25, No. 3, 2000, pp. 150-152. doi:10.1364/OL.25.000150

[7] Y. Matsuura, “Basics of Hollow Optical Fiber,” Medical Photonics, No. 2, 2010, pp. 11-15 (in Japanese).

[8] A. Vogel and V. Venugopalan, “Mechanisms of Pulsed Laser Ablation of Biological Tissues,” Chemical Reviews, Vol. 103, No. 2, 2003, pp. 577-644. doi:10.1021/cr010379n

[9] M. H. Niemz, “Laser-Tissue Interactions: Fundamentals and Applications,” Springer, Berlin, 1996, pp. 58-87. doi:10.1007/978-3-662-03193-3

[10] B. Choi and A. J. Welch, “Analysis of Thermal Relaxation during Laser Irradiation of Tissue,” Lasers in Surgery and Medicine, Vol. 29, No. 4, 2001, pp. 351-359. doi:10.1002/lsm.1128

[11] V. Venugopalan, N. S. Nishioka and B. B. Mikic, “Thermodynamic Response of Soft Biological Tissues to Pulsed Infrared-Laser Irradiation,” Biophysical Journal, Vol. 70, No. 6, 1996, pp. 2981-2993. doi:10.1016/S0006-3495(96)79868-5

[12] D. Obata, Y. Morita, R. Kawaguchi, K. Ishii, H. Hazama, K. Awazu, H. Kutsumi and T. Azuma, “Endoscopic Submucosal Dissection Using a Carbon Dioxide Laser with Submucosally Injected Laser Absorber Solution (Porcine Model),” Surgical Endoscopy, 2013, in Press. doi:10.1007/s00464-013-3029-x