Safe pleural contraction employing a new tip for electrosurgical units. An ex vivo experiment.

Background: Certain pulmonary lesions are treated by lung tissue contraction induced by heat administered by laser or electrosurgical unit (ES). ESs are comparatively less expensive, less complicated and more ubiquitous than a lasers but with their conventional tip carries the a risk of damaging the pleura. We developed a large ball tip (M-tip) for ES and evaluated its effect on the pleura in comparison with that of Nd:YAG laser in ex vivo lung.

Method: We employed lobes obtained through surgical resection. Using the Nd:YAG laser, the lung was irradiated for 2 seconds at levels of 5, 10 and 20 watts (10, 20 and 40 Joules). Using the M-tip ES, the pleura received treatment at levels of 10, 20 and 40 watts for 2 seconds (20, 40 and 80 Joules) in spray coagulation mode. Upon completion of these procedures, 144 tissue specimens obtained from 24 lobes were examined under light microscopy.

Results: Upon the application of Nd:YAG at 20 Joules, 22 (92%) of 24 visceral pleura demonstrated amorphous degeneration. With the application of ES at 40 Joules watts, 24 (100%) samples examined demonstrated amorphous degeneration (P = 0.47). Of the samples where pleural destruction was evident (Nd:YAG; 40 Joules, ES; 80 Joules), an accompanying air leak pattern (pleural destruction associated with slight parenchymal contraction) was observed in 5 (21%) of the samples treated with Nd:YAG and in 10 (42%) of those treated with the M-tip ES (p = 0.12).

Conclusion: The M-tip ES induced proper contraction of the pleura with relatively little destructive damage to the pleura at 40 Joules. Accordingly, it may be possible to induce pleural contraction using this new device with the same degree of safely that the Nd:YAG laser provides.