Experimental photoablation of meniscus cartilage by excimer laser energy

Abstract

Excimer lasers have been demonstrated to provide a very precise and circumscribed ablation of synthetic polymers and biological tissues. We investigated in vitro the use of ultrashort pulsed ultraviolet excimer-laser energy for controlled removal of meniscus cartilage under the aspects of arthroscopic meniscectomy. A krypton-fluorine gas mixture was used to achieve laser emission of 248-nm wavelength. A total of 22 human menisci obtained either by operation or necropsy were irradiated over a range of energy fluence (2.15-3.07 J/cm2/pulse), repetition rates (5-20 Hz), and exposure time (15-60s). Ablation rates of 4.00-5.76 microns per pulse were obtained. Light-microscopic examinations demonstrated tissue ablation without any evidence of pathological changes associated with continuous-wave laser irradiation. Effects of laser energy were clearly limited to the target of the laser beam, and tissue removal proceeded without production of heat or smoke. Due to the lack of pathological alterations observed, excimer-laser irradiation of meniscus cartilage may prove to be advantageous for precisely cutting and removing menisci without injury to the surrounding normal tissue. Clinical application of excimer-laser irradiation includes the development of suitable fiberoptics and laser coupling, as well as modification of fiber tips.

Photoablation of bone by excimer laser radiation

“…In our opinion, the excimer laser has its legitimacy in orthopedics, neurosurgery of spinal and intracranial nerve decompression, and cartilage surgery during arthroscopic operations [13,14]. In addition, this laser is a very useful tool for interventions in otolaryngology, in particular for surgery of the middle ear and maxillofacial surgery.…”

Holmiumlaser versus mechanische knorpelabtragung

“…Vergleichbare Nekrosezonen des Holmiumlasers an Meniskus und hyalinem Knorpel betrugen in der Elastikaffirbung am Kraterboden 400 IX und 550 IX und an den Seitenw/inden 250 IX und 300 IX [25]. Der vergleichsweise sehr geringen Gewebesch/idigung des Excimerlasers von 14-18 IX am Krater-boden und 4-12 g an den Seitenwfinden [8] und der M6glichkeit der optischen Strukturdiskrimination [21] stehen die Nachteile entweder einer starren Gelenkarmierung (248 nm), um Pulsenergien fiber der Abtragungsschwelle zu erzielen [8] oder bei Verwendung von Quarzfasern unrealistisch lange Bearbeitungszeiten [6,9,20] entgegen.…”

Excimer laser ablation of fibrocartilage: An in vitro and in vivo study

“…The basic mechanism of pulsed Excimer and continuous wave Nd:Yag lasers and the difference between their ablation characteristics have been discussed in various publications [6-91. It has been argued that the ablation characteristics of excimer lasers could provide potential advantages over continuous wave lasers in respect to the healing response of the remaining tissue [10,111. These results are in conformity with previous investigations in a variety of tissues [2-51.…”