title: Outcome after video-assisted thoracoscopic surgery and open pulmonary lobectomy in patients with low VO2 max: a case-matched analysis from the ESTS database†.
abstract: OBJECTIVE
  The aim was to verify the association of low VO2 max with postoperative morbidity and mortality after video-assisted thoracoscopic surgery (VATS) or open pulmonary lobectomy using the European Society of Thoracic Surgeons (ESTS) database.
  
  
  METHODS
  A retrospective analysis of data collected from the ESTS database was conducted. A total of 1684 lobectomy patients with available VO2 max values were included (2007-14). Patients operated through VATS (281 patients) or thoracotomy (1403 patients) were separately analysed. Propensity score analyses were performed to match patients with high (≥15 ml/kg/min) and low VO2 max (<15 ml/kg/min) for each approach. The following variables were used to construct the score: age, body mass index, predicted postoperative forced expiratory volume in 1 s (%), coronary artery disease, American Society of Anaesthesiology grade and Eastern Cooperative Oncology Group performance score. Cardiopulmonary morbidity and 30-day mortality were compared between the matched groups.
  
  
  RESULTS
  Mean VO2 max was 17.4 ml/kg/min. A total of 471 patients (28%) had low VO2 max. Overall postoperative cardiopulmonary morbidity and mortality rates were 30% (505 patients) and 4.1% (70 patients), respectively. Morbidity and mortality rates in low VO2 max patients were 33% (156 patients) and 6% (28 patients), respectively. After VATS, cardiopulmonary morbidity and mortality rates were 2-fold (13 of 72, 18% vs 143 of 399, 36%, P = 0.003) and 5-fold (1 of 72, 1.4% vs 27 of 399, 6.7%, P = 0.09) lower compared with thoracotomy. Matched comparison after thoracotomy (399 pairs): Mortality was significantly higher in patients with low VO2 max (27 patients, 6.7%) compared with those with high VO2 max (11 patients, 2.8%, P = 0.008). Complication rates were similar between the two groups (low VO2 max: 143 patients, 36% vs high VO2 max: 133 patients, 33%, respectively, P = 0.5). Matched comparison after vats (72 pairs): Morbidity and mortality rates of patients with low VO2 max were similar to those of patients with high VO2 max (morbidity: 13 patients, 18% vs 17 patients, 24%, P = 0.4; mortality: 1 patient, 1.4% vs 4 patients, 5.5%, P = 0.4).
  
  
  CONCLUSIONS
  Low VO2 max was not associated with an increased surgical risk after VAT lobectomy, which challenges the traditional operability criteria when this technique is used.
authors.affiliation: Department of Thoracic Surgery, St James's University Hospital, Leeds, UK.
authors.forename: Shah Sheikh Sofina
authors.initials: SS
authors.lastname: Begum
authors.affiliation: Department of Thoracic Surgery, St James's University Hospital, Leeds, UK.
authors.forename: Kostas
authors.initials: K
authors.lastname: Papagiannopoulos
authors.affiliation: Strasbourg University Hospital, Strasbourg, France.
authors.forename: Pierre Emmanuel
authors.initials: PE
authors.lastname: Falcoz
authors.affiliation: University Hospital Leuven, Leuven, Belgium.
authors.forename: Herbert
authors.initials: H
authors.lastname: Decaluwe
authors.affiliation: Ospedali Riuniti Ancona, Ancona, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Salati
authors.affiliation: Department of Thoracic Surgery, St James's University Hospital, Leeds, UK brunellialex@gmail.com.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Brunelli
mesh_terms: D000368:Aged; D016208:Databases, Factual; D006801:Humans; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D011013:Pneumonectomy / Q000009:adverse effects* / Q000379:methods / Q000401:mortality* / Q000706:statistics & numerical data; D011183:Postoperative Complications; D057216:Propensity Score; D012189:Retrospective Studies; D020775:Thoracic Surgery, Video-Assisted / Q000009:adverse effects* / Q000379:methods / Q000401:mortality* / Q000706:statistics & numerical data
keywords: Morbidity; Mortality; VAT lobectomy; VO2 max