ABSTRACTBACKGROUND:Patients with limited metastatic disease in the lung may benefit from metastasectomy. Thoracotomy is considered gold standard and video-assisted thoracoscopic surgery (VATS) is controversial because non-imaged nodules may be missed when bimanual palpation is restricted. Against guideline recommendations metastasectomy with therapeutic intent is now performed by VATS in 40% of thoracic surgeons surveyed. The evidence base for optimal surgical approach is limited to case-series and registries and no comparative surgical studies were observer-blinded.METHODS:Patients considered eligible for pulmonary metastasectomy by VATS prospectively underwent high-definition VATS by one surgical team followed by immediate thoracotomy with bimanual palpation and resection of all palpable nodules by a second surgical team during the same anaesthesia. Both surgical teams were blinded during preoperative evaluation of CT-scans and during surgery. Primary endpoints were number and histology of nodules detected.RESULTS:During a 12 months period 37 patients were included. Both surgical teams observed exactly 55 nodules suspicious of metastases on CT-scans. Fifty-one nodules were palpable during VATS(92%) and during subsequent thoracotomy 29 additional nodules were resected: 6(21%) were metastases, 19 (66%) were benign lesions, 3 (10%) were subpleural lymph nodes and one was a primary lung cancer.CONCLUSIONS:Modern VATS technology is increasingly used for pulmonary metastasectomy with therapeutic intent but several non-imaged and therefore unexpected nodules are frequent during subsequent observer blinded thoracotomy. A substantial proportion of these nodules are malignant and despite modern imaging and surgical technology they would have been missed if VATS was used exclusively for metastasectomy with therapeutic intent.