Our study groups 7 patients undergoing chest wall resection and 12 patients submitted to en bloc lung and chest wall resection. In the first group, 48 +/- 15 years old, there were 3 females (Darier-Ferrand fibrosis, chondroma, cutaneous gland epithelioma) and 5 males (3 sarcomas, 1 metastasis and 1 osteofibroma). An average of 2 ribs were resected with muscles, pleura and in 3 cases the skin, amounting to between 300 and 1,000 g. Reconstruction was performed : 1 degrees by musculocutaneous flap in 4 cases with 1 fistula; 2 degrees Marlex Mesh in 2 cases with 1 infection; 3 degrees fascia lata in the largest resection that necessitated tracheostomy and prolonged ventilation. There was no death. In the second group, 61 +/- 14 years old, all males, there were 9 bronchial carcinomas and 3 sarcomas. An average 2.5 ribs were resected en bloc with 6 lungs and 6 lobes. The defect was treated : 1. by Marlex Mesh in 3 cases without complications, 2 had tracheostomy and 2 days ventilation; 2. by muscle flap in 9 cases with 3 tracheostomies and ventilation up to 1 month : there were 3 empyemas and 2 atelectasiae. One patient died after a second operation for bronchial stump necrosis. On the whole there is no need for Marlex Mesh.