In vitro study of ablated lung tissue in Nd:YAG laser irradiation.

BACKGROUND

Neodymium:yttrium-aluminum garnet lasers are used to reduce lung volume. An assessment of the relationship between the histologic and gross findings in the lung irradiated by a laser would be helpful in laser-assisted pneumoplastic procedures.

METHODS

In vitro lung lobes surgically resected for pulmonary carcinomas were irradiated with a neodymium:yttrium-aluminum garnet laser at three energy levels in three modes: contact rubbing, contact pointing, and noncontact. Pleural degeneration in 216 samples from 24 lobes was classified as coagulative, amorphous, or destructive. At all energy levels, the laser was applied for 1.5 seconds.

RESULTS

Noncontact mode at 7.5 W or 15 W and contact rubbing at 5 W caused coagulative or amorphous degeneration but no destructive degeneration. The energy level correlated with the color of the degenerated pleura. The incidence of destructive pleural degeneration, which led to air leaks as revealed by an air inflation test, was 0% in pink and white samples, 59% in brown samples, and 100% in black samples (p < 0.0001, white versus brown samples).

CONCLUSIONS

In neodymium:yttrium-aluminum garnet laser ablation of lung tissue, the color of the degenerated pleura correlates with the intensity of the applied laser energy and the degree of pleural degeneration.