DISTENSION OF EXTRAPLEURAL SPACES WITH CONTRAST-MEDIUM OR AIR - VALUEIN CREATING SAFE PERCUTANEOUS ACCESS TO THE MEDIASTINUM IN CADAVERS

OBJECTIVE. We artificially widened the extrapleural space with contras t medium or air in 33 cadavers to create a safe extrapleural route to the anterior mediastinum and the posterior mediastinum for large-bore needle biopsies. MATERIALS AND METHODS. Under CT guidance, 120 ml of d iluted contrast medium (10%) or 300 ml of air was injected percutaneou sly into the right paravertebral (n = 23) and left retroaortic (n = 5) or ventral parasternal (n = 5) extrapleural spaces. RESULTS. In six o f 18 cases, the paravertebral space was found to be wide enough to adv ance a 14-gauge cannula to the extrapleural paraesophageal space, Afte r injection of 120 mi of diluted contrast medium, the width of the rig ht paravertebral space at the level of the posterior rim of the verteb ral body was dilated from a mean of 0.62 cm to 1.06 cm, and the width of the anterior rim was dilated from a mean of 0.91 cm to 1.97 cm. In 17 of 18 cases, the paravertebral space was wide enough to accommodate a 14-gauge cannula. A large osteophyte blocked the access route in on e case, Artificial widening regresses within 7 min by an average of 33 % at the level of the posterior rim of the vertebral body and by an av erage of 18% at the level of the anterior rim, Dilatation was signific antly more effective with diluted contrast medium than with air, When 120 mi of diluted contrast medium was injected into the left retroaort ic extrapleural space, the distance between the aorta and the vertebra l column was widened from a mean of 0.40 cm to 1.50 cm. Using a ventra l approach for injecting 120 mi of solution, we widened the parasterna l access route from a mean of 0.42 cm to 1.90 cm. CONCLUSION. In this cadaver study, artificial dilatation of the mediastinum with diluted c ontrast medium allowed extrapleural access from right paravertebral, l eft retroaortic, and parasternal directions for large-bore needle biop sies.