[An ex vivo study on the vaporization ratio of the prostatic tissue lased by the 2 micron laser].

Objectives: To observe the vaporesection efficiency of the 2 micron laser to the prostatic gland in benign prostatic hyperplasia, and investigate the method of estimating the amount of the vaporesected prostatic tissues during transurethral vaporesection of the prostate using the 2 micron laser system in the treatment of benign prostatic hyperplasia.

Methods: Total 9 fresh prostatic gland specimens were obtained from patients with BPH under open surgical procedures, and vaporesected under a simulated transurethral environment with the 2 micron laser system immediately after weighted. Energies and time consumptions were noted, collections of vaporesected tissue specimens and the remnants of the prostatic glands were weighted after the procedures. The ratios of the vaporized tissues and the collected tissues to the whole vaporesected tissues were calculated respectively. The vaporesection efficiency of the 2 micron laser to the prostatic tissues was also calculated.

Results: Among the total lost tissues, about (65.6 +/- 1.5) percent of which were that of vaporized, and nearly (34.5 +/- 1.5) percent were resected. Linear correlation between the weight of collected prostatic tissue(x) and the weight of prostatic gland specimens(y) could be defined as a formula of [y = 3.245x - 6.475 (t = 15.097, P = 0.000)].

Conclusion: The amounts of the whole prostatic tissues removed by the 2 micron laser could be calculated from the collected resected prostatic specimens under a simulated transurethral surgical procedure.