Proportions (%) of complications as classified by mCDS scoring (minor to severe complications, from grade 1 to 5).

Grade 1 (n = 9): Wound leakage, constipation, nonsevere lung infection; Grade 2 (n = 5): Non severe dura mater breach, delayed wound healing; Grade 3 (n = 2): Deep wound infection, treated with second surgery + IV antibiotics; Grade 4 (n = 10): Any complication requiring ICU admission: Complex deep wound infection, renal failure, urinary sepsis, severe lung infection, delayed awakening after anaesthesia, central venous catheter infection; Grade 5 (n = 2): Per operative death or early postoperative death (within 7 days); NA (n = 2): Missing data.