Predictors of conversion to thoracotomy for video-assisted thoracoscopic lobectomy: A retrospective analysis and the influence of computed tomography-based calcification assessment

Objective: Conversion to an open thoracotomy during video-assisted thoracoscopic surgery lobectomy is reported to occur in up to 23% of cases and can be associated with increased morbidity. We developed a preoperative computed tomography calcification score based on anatomic location and extent of calcifications to evaluate the ability to predict video-assisted thoracoscopic surgery conversion. Methods: Patients undergoing planned video-assisted thoracoscopic surgery lobectomy between 2003 and 2009 were identified. Baseline demographics, comorbidities, operative data, and postoperative outcomes were reviewed. Preoperative chest computed tomography scans were examined by an attending thoracic surgeon. Calcifications were scored from 0 (none) to 6 (major hilar calcifications at the resection bronchus). Preoperative patient and tumor characteristics and the calcification score were analyzed for their ability to predict conversion. We then compared outcomes among patients undergoing video-assisted thoracoscopic surgery, converted vide-oassisted thoracoscopic surgery, and planned open thoracotomy. Results: Of the 193 patients undergoing planned video-assisted thoracoscopic surgery lobectomy, 148 (77%) had a completed video-assisted thoracoscopic surgery lobectomy, and 45 (23%) underwent conversion to thoracotomy. The calcification score was found to independently predict video-assisted thoracoscopic surgery conversion. Patients who were converted to a thoracotomy had significantly higher 30-day mortality, more atrial arrhythmias, increased blood loss, longer operative time, and increased length of stay compared with those who underwent completed video-assisted thoracoscopic surgery lobectomy and longer length of stay compared with those undergoing planned open lobectomy. Conclusions: Calcification score based on the location and degree of calcifications can predict the increased likelihood of video-assisted thoracoscopic surgery conversion. This scoring system could be one element used to choose the approach for a lobectomy, especially during a surgeon's learning curve.