Does the source of laser energy influence the coagulation of chorionic plate vessels? Comparison of Nd:YAG and diode laser on an ex vivo placental model.

ABSTRACT

OBJECTIVES: To compare the histological effects of diode and Neodymium-Yttrium Aluminium Garnet (NdYAG) laser coagulation of chorionic plate vessels. METHODS: In selected chorionic plate vessels in an ex vivo term placenta perfused with warm saline solution, diode (wavelength 940 nm) and NdYAG (wave length 1,064 nm) laser were used with an output of 30, 40, and 50 W, and 55 and 70 W respectively using preset energy and duration of impact. All vessels were examined histologically blindly to the procedures' characteristics. RESULTS: A total of 23 vessels were coagulated. Similar histological lesions were observed using diode and NdYAG lasers. The lesions were compatible with an acceptable clinical effect at all power outputs tested. The results were not related to the diameter or type of vessels. Lesions of the endothelium and reduction of the vessel lumen were best achieved with a diode laser at 40 W. CONCLUSION: NdYAG and Diode laser induce significant and comparable changes in chorionic plate vessels compatible with an efficient coagulation process under the experimental condition used.