Impact of early versus late-onset mediastinitis on outcomes after upper gastrointestinal surgery.

backgroundMediastinitis is a rare but life-threatening complication after upper gastrointestinal (GI) surgery. Although advances in perioperative care have improved outcomes, the prognostic impact of the timing of onset remains unclear. Clarifying whether early-onset versus late-onset mediastinitis influences clinical, microbiological, and surgical outcomes is essential to guide management.

methodsWe retrospectively analyzed 27 patients with mediastinitis after upper gastrointestinal surgery treated at our center between 2015 and 2025. Our institution is a tertiary-level, high-volume center performing complex upper GI procedures. During this period, 728 patients underwent upper GI surgery, among whom anastomotic leakage occurred in 44 (6.1%), and mediastinitis developed in 27 (3.7%). Patients were classified into early-onset (≤14 days) and late-onset (>14 days) mediastinitis groups based on the postoperative interval. Demographic and clinical variables, comorbidities, smoking history, malignancy status, microbiological culture results, surgical interventions, intensive care unit (ICU) admission and duration, hospital stay, duration of antibiotic treatment, complications, and mortality were recorded and compared.

resultsDuring the 10-year study period, 728 patients underwent upper gastrointestinal surgery at our institution, and mediastinitis developed in 27 patients (3.7%) following esophageal or gastric procedures. The median age was 64 years [interquartile range: 54-74.5], and 55.6% were male. Malignancy was present in 70.4%, most frequently gastric adenocarcinoma (n=6). Overall, ICU admission was 81.5%, with a median ICU stay of two days, and mortality occurred in eight patients (29.6%). Culture positivity was observed in 16 patients (59.3%), most commonly with Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter spp. Compared with late-onset mediastinitis, early-onset mediastinitis was associated with significantly shorter ICU stay (median 1 vs. 6.5 days, p=0.020), hospital stay (16 vs. 41 days, p=0.003), and antibiotic duration (14 vs. 35 days, p=0.002). The early-onset group demonstrated a lower mortality rate than the late-onset group (17.6% vs. 50.0%, p=0.102). Late-onset mediastinitis correlated with higher culture positivity and a greater need for complex surgical procedures, including video-assisted thoracic surgery (VATS), thoracotomy, and endoscopic stenting. Reoperations were required in 13 patients (48.1%). When stratified into abdominal and thoracic procedures, abdominal re-operations were more frequently observed in the late-onset group (5/8, 62.5%), whereas thoracic reoperations predominated in the early-onset group (4/5, 80%). Patients without reoperation constituted 51.9% of the cohort (14/27).

conclusionEarly-onset mediastinitis after upper GI surgery is associated with improved outcomes. It correlates with better survival, shorter ICU and hospital stay, reduced antibiotic treatment, and a lower need for complex surgical procedures, whereas late-onset mediastinitis is linked to higher microbial burden, more frequent reoperations, and poorer outcomes.