Negative surgical exploration for CT-proven pneumoperitoneum: a diagnostic pitfall in suspected gastrointestinal perforation—a six-case series

Background Computed tomography (CT) plays a vital role in diagnosing suspected gastrointestinal perforation (GIP), particularly in the presence of pneumoperitoneum and intra-abdominal fluid. Nevertheless, these radiologic findings do not invariably correspond to bowel perforation, and negative surgical exploration may occur. We conducted this study to characterize the clinical features and outcomes of patients who underwent emergency surgery for suspected GIP but had no perforation. Methods We retrospectively reviewed consecutive non-trauma patients who underwent emergency surgical exploration during 2021–2025 for CT-confirmed pneumoperitoneum with fluid collection. Among 1,024 emergency surgical explorations (excluding appendectomies), 11 (1.1%) were classified as negative explorations, of which five cases without pneumoperitoneum were excluded, leaving six patients for analysis. We evaluated their clinical characteristics, laboratory findings, operative details, and 90-day outcomes. Results The median age of the patients was 67.5 years [interquartile range (IQR): 58–77], and three patients (50%) were men. All patients presented with abdominal pain, with a median symptom duration of 84 h (IQR: 72–148). The median white blood cell count was 13.2 × 10 9 /L (IQR: 8.7–17.7), and the median C-reactive protein level was 23.6 mg/dL (IQR: 19.8–29.7). Final diagnoses included primary peritonitis ( n = 1), sealed duodenal microperforation ( n = 1), peritoneal abscess secondary to urinary tract infection ( n = 2), severe oophoritis ( n = 1), and soft tissue infection related to Fournier's gangrene ( n = 1). The median intensive care unit (ICU) and hospital lengths of stay were 16 (IQR: 6–39) and 28.5 (IQR: 18–78) days, respectively. One patient died within 90 days (16%). Conclusion Pneumoperitoneum with fluid collection on CT does not invariably indicate bowel perforation. In clinically stable patients with prolonged symptoms, a brief period of careful observation and reassessment may be appropriate. These findings underscore the importance of integrating radiologic features with clinical judgment to guide surgical decision-making.