Evaluation of novel nonlaser light source for endometrial ablation using 5-aminolevulinic acid

Background and Objective: This research evaluated the effectiveness of a ne w nonlaser prototype short-are lamp to achieve photodynamic ablation of end ometrium in a rat. Study Design/Materials and Methods:Thirty female Sprague-Dawley rats were d ivided into two groups. Ei-Aminolevulinic acid (ALA), the precursor to the photosensitizer protoporphyrin IX,was injected into the left uterine horn a nd vehicle alone (Hyskon) was injected into the right horn of 23 rats (grou p 1). An additional seven rats received vehicle only into both uterine horn s (group 2). Three hours later, a cylindrical diffusing optical fiber was i nserted into the lumen of the uterine horns, and light treatment was delive red from either a laser or a nonlaser light source. Rats in group 1 receive d either 1 hour (n = 15) or 10 minutes (n = 8) of light treatment into both uterine horns. In rats in group 2, the left horn was exposed to 1 hour of light treatment. Uterine tissues were examined histologically 4 days after light treatment. Results: One hour of light exposure to the uterine horns injected with ALA produced extensive necrosis of the rat uterine wall. No difference in the m agnitude of destruction was seen between the groups treated with the laser and nonlaser light sources. Ten minutes of light exposure resulted in endom etrial ablation that was comparable in both the laser- and the prototype-tr eated groups, but the destruction of the deepest layers of the uterine wall was more consistent in the group treated with the nonlaser prototype. One hour of light treatment from either light source did not result in any hist ological changes in the uterine horns not exposed to ALA. Conclusion: The extent of endometrial ablation in the rat uterine horn achi eved with the nonlaser prototype was comparable to that achieved with the l aser. Thus, the nonlaser prototype may provide a less expensive approach to photodynamic endometrial ablation. (C) 1999 Wiley-Liss, Inc.