Nerve sparing surgery in advanced stage thymomas.

BACKGROUND: Phrenic nerve infiltration has been described in up to 33% of advanced thymomas; en-bloc resection causes diaphragmatic loss of function, with detrimental effects on pulmonary function. We report the outcomes of selected patients operated on for invasive thymoma with a "nerve sparing" technique.

METHODS: From 1990 to 2015 we used "nerve sparing" surgery with the intention to treat all patients with advanced stage thymomas without preoperative evidence of hemi-diaphragmatic palsy, but with macroscopical evidence of phrenic nerve involvement. All patients underwent adjuvant radiotherapy (45-60 Gray) with or without chemotherapy. Long-term outcomes and the pattern of recurrence were retrospectively analyzed.

RESULTS: Among 140 patients with stage-III and IVa operated on during the study period, 19 females and 18 males with a median age of 52 years, received a nerve sparing resection. Myasthenia Gravis was associated in 25 cases. In 12 patients, phrenic palsy was observed post-operatively, which eventually recovered in 4 of them. Recurrence was found in 10 patients (7 stage-IVa, 3 stage-III) requiring additional therapies. Three patients died due to cancer-related causes with an Overall Survival of 265.4 months and a Disease-Free Survival of 233.2 months.

CONCLUSIONS: Phrenic nerve preservation in cases of invasive thymomas is feasible and may warrant an acceptable local control of disease, if associated with radiotherapy. According to these results, this technique could be proposed to all patients with invasive thymoma, especially in those affected by severe comorbidities or with a poor performance status.