Thoracoscopic Ultrasonography Versus Manual Lung Palpation by Thoracotomy for the Identification of Lung Nodules During Pulmonary Metastasectomy. A Prospective Blinded Cross-over Trial.

Pulmonary metastasectomy is a surgical practice that poses many aspects of debate: standard approach has historically been represented by open thoracotomy, but video-assisted thoracic surgery (VATS) became an appealing alternative due to the lower surgical impact on the patient. Some authors blame the minimally invasive approach for pulmonary metastasectomy as less effective from an oncologic point of view since lung palpation is hampered, leading to reduced ability to identify unexpected nodules and potential impairment of surgical radicality.

Indeed, several papers demonstrated a suboptimal sensitivity of computed tomography (CT) and positron-emission tomography (PET) in detecting lung metastases and discover of further unexpected nodules at thoracotomy are not an uncommon eventuality.

A few authors demonstrated the utility of intraoperative lung ultrasound performed through a VATS approach (VATS-US) in identifying lung nodules. However, the real effectiveness of this technique has never been prospectively compared with the current gold standard represented by open thoracotomy and lung manual exploration. Aim of our study is to assess the non-inferiority of VATS-US compared with manual palpation to identify lung nodules during pulmonary metastasectomy.

The study design is a monocentric non-inferiority diagnostic crossover trial, based on the execution of intraoperative lung ultrasound (VATS-US) in patients undergoing pulmonary metastasectomy with radical intent. Aim of the study is to assess the non-inferiority of the ultrasonographic investigation on the lung parenchyma performed via a thoracoscopic approach in identifying lung nodules compared with manual organ palpation by thoracotomy.

Study design After general anesthesia administration patients will be intubated with a double lumen tube and positioned in a standard lateral decubitus. Thereby the target lung will be excluded from ventilation and deflated. After creation of 2-3 thoracoscopic ports the lung is explored under thoracoscopic vision with a laparoscopic ultrasound probe (Esaote LP323, Esaote, Genova, Italy) by a surgeon with experience on the use of lung ultrasound. Data regarding number, size, depth and lobar localization of nodules are registered on a data collection paper. The surgeon who performed the investigation therefore leaves the operative room and another surgeon, blind to the previous phase findings, performs an anterolateral thoracotomy and an accurate palpation of the lung. Suspicious nodules are therefore resected and sent for histology. Data on number and localization of excised nodules are registered on a separate collection paper. Results from both phases are then compared and matched with histology report.