Radiographic identification of thoracoabdominal hernias

Abstract

Hernias spanning both chest and abdominal walls are uncommon and associated with chest wall trauma, coughing and obesity. This study describes the radiographic appearance of these hernias to guide proper identification and operative planning. Proposed standardized reporting patterns are also presented. The cross sectional imaging of patients presenting with thoracoabdominal hernias was reviewed. Radiographic reports were supplemented by surgeon imaging review and operative findings during repair. Defect dimensions, hernia content, level of herniation, presence of osseous or cartilaginous disruption of the chest wall and degree of rib displacement were collected. Disruption of myofascial planes was also noted. Six patients were identified. All hernias occurred below the 9th rib and were associated with complete intercostal muscle disruption. The transversus abdominis was disrupted in all hernias and the internal oblique was disrupted in five of the hernias. The majority (83%) had caudal rib displacement (median 6.8 cm compared to contralateral side). Median hernia width was 10.35 cm (1.6–19.1 cm) and median length was 10.2 cm (1.8–14.3 cm). Five patients had associated bone/cartilage injuries: two with 11th rib fractures, two with combined bone and cartilaginous fractures and one with a surgical rib resection. The typical injury pattern of thoracoabdominal hernias includes disruption of the intercostal muscles, transversus abdominis, and commonly the internal oblique with an intact external oblique. Inferior rib displacement by hernia contents and unopposed pull of the abdominal musculature is common. Osseous or cartilaginous disruption always occurs unless the defect is bounded on at least one side by a floating rib.