Gastro-duodenal perforations: conventional plain film, US and CT findings in 166 consecutive patients

Gastro-duodenal perforations may be suspected in patients with history of ulceration, who present with acute pain and abdominal wall rigidity, but radiological findings in these cases may be unable to confirm a clinical diagnosis. The aim of our study was to report our experience in the diagnosis of gastro-duodenal perforation by conventional radiography, US and CT examinations.

We retrospectively reviewed medical records of 166 consecutive patients who presented in the last 2 years to our institutions with symptoms of acute abdomen and submitted to surgery at the Emergency Unit of the "A.Cardarelli" Hospital of Naples with a surgical finding of perforated gastro-duodenal ulcer. The evidence of free intraperitoneal air on abdominal plain film was considered as a direct or suggestive finding of perforation. Evidence of intraperitoneal free fluid and/or reduced intestinal peristalsis at sonographic examination were considered indirect signs of gastro-duodenal perforation. Evidence of free peritoneal gas at CT was considered as a direct evidence of gastro-duodenal perforation.

Twenty patients underwent immediate surgery with no preoperative imaging evaluation, in 10 of them the site of perforation was found in a juxta-pyloric region and in the others at level of duodenum. In 146 patients submitted to serial radiological investigations before surgery, the site of perforation was in 56 (38.3%) duodenal, in 52 (35.6%) juxta-pyloric, in 28 (19.1%) gastric and in 10 (6.8%) pyloric. The cause of perforation was in all cases gastric or duodenal ulceration, in seven cases involving pancreatic parenchyma. In 110 (75.4%) patients with direct findings of perforation, in 94 cases (85.5%) the correct diagnosis was established on abdominal plain film, in two (1.8%) with radiographic and sonographic examinations and in 14 (12.7%) on CT findings. In 36 (24,6%) patients with no direct findings of perforation, only 24 (16,4%) of them showed indirect findings of perforation. In other 12 patients no direct or indirect finding of free peritoneal air was detected.

Our experience documents that in 146 gastroduodenal perforations the free peritoneal air was not evident in 12 cases and in 66% of these patients the presence of intraperitoneal fluid could be the only sign of perforation. If free peritoneal air was detected with conventional radiography, other investigations were not indicated. In the absence of direct or indirect findings of pneumoperitoneum, US examination could help to confirm intestinal paresis and the evidence of intraperitoneal free fluid. Helical CT examination was useless before at least 6h from the onset of symptomatology, because in the absence of direct or indirect findings of penumoperitoneum at abdominal plain film and sonograpy, CT could not demonstrate any additional diagnostic information.