Empirical Study On Effects Of Combination Of Nd:YAG Laser And PYM To The Veins Of Rabbit Ears

Objective The aims of the study were to observe the lesion effects of combination of Nd:YAG laser and PYM to the veins of rabbit ears by animal experiment and to investigate the combined effects to venous malformation. So the theory proofs of the therapeutic alliance could be confirmed and the new better therapy for venous malformation in clinic could be applied.Methods In the study of randomized block design, 37 New Zealand white rabbits (74 ears in all) were divided into 4 groups (respectively named Group A, B, C, D). 12 in the Group A (Experiment Group), the normal vein of each rabbit ear was injected PYM 0.3ml (Concentration is 4mg/ml). Seven days after the injection, the same part of the vein was sweepingly irradiated by Nd:YAG laser (Energy Density is 2547.8J/cm~2 ). 12 in the Group B (Control Group), the normal vein of each rabbit ear was only injected PYM 0.3ml (Concentration is 4mg/ml). 12 in the Group C (Control Group), the normal vein of each rabbit ear was only sweepingly irradiated by Nd:YAG laser (Energy Density is 2547.8J/cm~2). The Group D (Blank Group) includes only 1 normal rabbit which the specimens of normal vein were examined as a primary standard for the purpose of observing the specimens of the Group A, B, C. Four specimens of the Group A, B, C were taken in 1d, 3d, 7d, 14d, 21d, 28d and examined by light microscopy. The specimens of 14d and 28d were examined by transmission electron microscopy. The results of the specimens observed by light microscopy were ranked and scored according to the degree of injury of vein and then that data were compared with control groups (the group of injection PYM and the group of irradiation Nd:YAG laser). All ranked data were analyzed by software of statistics.Results (1) Compared the damage degrees of veins with ones of the Group B (control group of PYM), in the Group A (Experiment Group), there was the significant difference in 14d, 21d and 28d (P<0.05). In the Group A, there was the significant difference in 7d,14d, 21d and 28d (P<0.05) compared the damage degrees of veins with ones of the Group C (control group of YAG). (2) The damage degree of wall of vein and blood vessel endothelium (BVE) was more severe from 1d to 28d in the Group A. In 28d, the lumens was narrowed and the cellularoedema of vascular endothelial cell (VEC), endomembrane swelling, the mural thrombosis could be observed by light microscopy. In the Control Groups, the damage degree of wall of vein and VEC was severe from 1d to 14d. Fourteen days after injection or irradiation, the BVE was becoming repaired and recovered although cellularoedema of the VEC, endomembrane swelling and small immaturity thrombus also could be seen. The light mesenchyme fibrosis in 14d and the narrow lumens in 28d could be observed, but the damage of wall of vein was recovered and the thrombus could not be found.Conclusion (1) Compared with the single irradiation Nd:YAG laser or injection PYM, the damage degree of the VEC in veins of rabbit ears that were treated by therapeutic alliance of PYM and Nd:YAG laser is more severe, and the action time is longer. The therapeutic efficacy of the therapy method which irradiation Nd:YAG laser combines with injection PYM to treat venous malformation is better than the single one. (2) Therapeutic alliance of PYM and Nd:YAG laser can injure wall of vein and VEC more hardly so that can treat venous malformation by thrombosis and narrow lumens.