Thoracoscopic electrode implantation for diaphragm pacing in dogs.
BACKGROUND
Diaphragm pacing is an attractive method of ventilatory support; however, it requires electrode implantation to the phrenic nerve or diaphragm. The thoracic approach is favored for several reasons, and it usually accompanies invasive bilateral thoracotomy.


OBJECTIVE
This study was conducted to develop a new electrode suitable for video-assisted thoracoscopic implantation, which is less invasive than the conventional thoracic approach.


METHODS
The feasibility of video-assisted thoracoscopic implantation was tested with newly designed electrodes using 5 mongrel dogs. Furthermore, diaphragm pacing was performed for 60 min to test whether or not the implanted electrodes were functional.


RESULTS
Video-assisted electrode implantation was successful in all 5 cases. No complications occurred during the implantation procedure. In acute-phase pacing trials, the electrodes stimulated the phrenic nerves for 60 min without any pacing failures. The mean value of PaCO(2) increased gradually from 32.2 +/- (SEM) 1.52 to 54.6 +/- 4.58 mm Hg, and the value of tidal volume decreased gradually from 242.9 +/- 31.3 to 147.5 +/- 24.5 ml in 60 min pacing.


CONCLUSIONS
The thoracoscopic implantation of new electrodes was less invasive, and was a safe procedure for diaphragm pacing. Meticulous care should be taken to avoid muscle fatigue.
Shoji
Tsuyoshi
T
Department of Thoracic Surgery, Kyoto University Hospital, Kyoto, Japan.
Oku
Yoshitaka
Y
Ishikawa
Shinya
S
Wada
Hiromi
H
D000704:Analysis of Variance; D000818:Animals; D003964:Diaphragm / Q000294:innervation* / Q000503:physiopathology; D004285:Dogs; D004599:Electric Stimulation Therapy / Q000295:instrumentation* / Q000379:methods; D004567:Electrodes, Implanted; D005260:Female; D008297:Male; D023421:Models, Animal; D011336:Probability; D012121:Respiration, Artificial / Q000379:methods*; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D020775:Thoracic Surgery, Video-Assisted / Q000379:methods*