Preservation of phrenic nerve involved by stage III thymoma

In stage III thymoma, the involved organs are usually resected to achieve complete resection. However, inclusion of the phrenic nerve (PN) in the resection may compromise pulmonary function which may be critical for the patients with serious complications.

We retrospectively analyzed 18 thymoma patients with Masaoka stage III thymoma that involved the PN to determine the effects of PN resection versus PN preservation on postoperative pulmonary function, survival, and relapse.

The PN was resected in 9 patients and preserved in 9 patients. The PN resection was avoided because of severe myasthenia gravis (n = 3), myotonic dystrophy (n = 1), old age (>80, n = 2), and minimal involvement (n = 3). Resection of the PN resulted in reduction of vital capacity and forced expiratory volume in the first second of expiration to 66% and 69%, respectively, of the preoperative values. Chronic respiratory failure appeared gradually in one patient in the PN resection group and he died without relapse 28 months postoperatively. In the PN preservation group, postoperative PN paralysis appeared in 8 of 9 patients and the paralysis was recovered in 7 of 8 patients. Postoperative vital capacity and forced expiratory volume in one second recovered to 92.4% and 94.1% of the preoperative values. Although relapse was observed more frequently in the PN preservation group and relapse-free survival seems to be longer in the PN preservation group (p = 0.073), there was no difference in overall survival between the groups.

It may be an option to preserve the involved PN in stage III thymoma especially in the patients with serious complications.