Impact of Timing of Conversion to Open Surgery on Short-Term and Oncologic Outcomes in Patients Undergoing Minimally Invasive Surgery for Colorectal Cancer.

To evaluate the influence of timing of open conversion on short-term and oncologic outcomes after minimally invasive surgery for colorectal cancer. Six hundred forty-six consecutive patients were enrolled. All patients converted to open surgery were classified into early (n = 10) or late (n = 67) groups based on conversion timing using a 60-minute cutoff. A comparison of early conversion and nonconverted groups showed that history of prior abdominal surgery and pT4 tumor was more common in the early conversion group. Mean operative time was longer in the early conversion group. Rates of 30-day postoperative complications (30% vs 27%), time to soft diet (5 days vs 5 days), and hospital stay (12 days vs 12 days) were not different. A comparison of the late and nonconverted groups showed that history of prior abdominal surgery was more common in the late conversion group. Mean operative time was longer in the late conversion. Rates of 30-day postoperative complications (42% vs 27%), Clavien-Dindo score ≥3 (22% vs 11%), intensive care unit care (31% vs 15%), and transfusion (37% vs 21%) were significantly higher in the late conversion group. Time to soft diet (6 days vs 5 days) and hospital stay (15 days vs 12 days, P = 0.037) were longer in the late conversion group. Cancer-specific and recurrence-free survival rates did not differ among the early, late conversion, and nonconverted groups. Decisions about open conversion need be made within 60 minutes of the beginning of surgery as early conversion does not worsen short-term and oncologic outcomes.