Surgical site infections after lung resection: a prospective study of risk factors in 1,091 consecutive patients

Background: To assess incidence and risk factors of surgical site infections (SSI) (wound infection, pneumonia, empyema) in a monocentric series of patients undergoing lung resection over a decade.

Methods: All patients undergoing lung resection at our institution in 2006-2015 [wedge resection, n=579; lobectomy, n=472 (12% after chemo/radiotherapy); pneumonectomy, n=40 (47% after chemo/radiotherapy)], were prospectively enrolled. Perioperative SSI risk factors were recorded: age, gender, blood haemoglobin, lymphocyte count, serum albumin, forced expiratory volume in 1 second percentage (FEV1%) of predicted, antibiotic prophylaxis, length of stay, diabetes, malignancy, steroid therapy, induction chemo/radiotherapy, resection in 2006-2010/2011-2015, urgent/elective procedure, videothoracoscopic/open approach, resection type, operative time. SSIs diagnosed within 30 days from surgery were prospectively recorded and association with risk factors was evaluated.

Results: Of the 1,091 resected patients [median age, 65 (range, 13-91) years; male, 74%; malignancy, 65%], 124 (11.4%) developed one or more SSI. Wound infection, pneumonia and empyema rates were respectively 3.2%, 8.3% and 1.9%, stable through the decade. Overall infection rates after wedge resection, lobectomy and pneumonectomy were 4.8%, 17.4% and 35.0%, respectively. Thirty-day postoperative mortality was 0.6%; of the 7 deaths, 4 were causally related with SSI. Multivariable analysis showed that male gender, diabetes, preoperative steroids, induction chemo/radiotherapy, missed antibiotic prophylaxis and resection type were independent risk factors for overall SSI.

Conclusions: SSI rates after lung resection were stable over the decade. The observed 11.4% frequency of SSI indicates that postoperative infections remain a relevant issue and a predominant cause of mortality after lung surgery. Focusing on SSI risk factors that are perioperatively modifiable may improve surgical results.