Blebs were endoscopically visible in only about one half of the group, and healing occurred in most members of this group following coagulation therapy. Consequently, therapeutic efficacy was directly related to our ability to visualize blebs. In only five cases (16 percent) in which blebs could be visualized was therapy unsuccessful; however, three of these cases involved giant blebs with a diameter of 4 cm or greater, and two cases involved multiple blebs. If we consider only those cases in which all blebs were visible, an excellent success rate of 17 out of 22 cases (77 percent) was achieved.
In 9 cases (29 percent) where blebs were totally invisible, thoracotomy was performed to confirm that in 6 (19 percent) of the 31 cases, pleural adhesions made visualization impossible, and in 3 cases (10 percent), the blebs were hidden behind the lungs, eg, on the mediastinal septum. Based upon these results, we concluded that in order to improve the cure rate following endoscopic therapy and to further reduce the number of cases requiring thoracotomy, it was necessary to broaden the visible range of the thoracoscope and be able to cope with giant and multiple blebs. These conclusions motivated our use of a FB for subsequent thoracoscopies.