All 32 lesions created had visible extension to the hepatic surface. All 7 control lesions produced transdiaphragmatic injury (grade 3), including one of which injured the nearby lung parenchyma.

Fig.: Figure 14: Gross picture showing discolored segment of lung caused from RFA of adjacent liver without protective balloon.

Of the 25 balloon protected lesions, 21 lesions (84%) had no associated diaphragmatic injury (grade 0), two lesions (8%) had minimal diaphragmatic injury.

Fig.: Figure 15: Gross picture showing discolored segment of ablated liver lesion. Balloon device is seen overlying the liver surface. The adjacent corresponding diaphragm shows no signs of injury.

Fig.: Figure 16: Representative magnified photomicrograph of diaphragmatic section with typical grade 3 injury. Arrows point to injured diaphragmatic muscle. Notice the relative paucity of muscle nuclei.

Fig.: Figure 17: Representative photomicrograph of diaphragmatic section taken from an adjacent balloon protected diaphragm. The diaphragmatic muscle is completely intact and normal in histologic appearance (Grade 0).

Two of these lesions had associated moderate diaphragmatic injury (8%). These two lesions, however, had the complication of protective balloon device rupture during the ablation procedure. Therefore, the balloon had not been completely inflated, and thereby the diaphragm not completely protected, during the creation of these lesions.