To analyze the preoperative detection of hiatal hernia (HH) and related factors in patients undergoing anti-reflux surgery, and to compare the report-based detection proportions of barium esophagography, upper gastrointestinal endoscopy, and thoracoabdominal computed tomography (CT) among patients with intraoperatively confirmed HH.

This single-center retrospective study included 94 patients who underwent fundoplication with HH repair for gastroesophageal reflux disease (GERD) at Sir Run Run Shaw Hospital Affiliated to Nanjing Medical University, between December 2023 and April 2026. All patients underwent preoperative barium esophagography, upper gastrointestinal endoscopy, and thoracoabdominal CT. Judgment was determined from the original formal clinical reports. HH reported by at least one examination was defined as the preoperative detection group, whereas no HH reported by any examination was defined as the preoperative non-detection group. Firth penalized logistic regression was used to identify factors independently associated with preoperative detection, and Cochran's Q test was used to compare the paired detection proportions of the three examinations. Because only reference-standard-positive surgical cases were included in this study, the detection proportion only reflects the case detection situation within this specific surgical population. Specificity, positive and negative predictive values, and overall diagnostic accuracy could not be estimated.

Among the 94 patients, 31 cases (33.0%) were detected before the operation, while 63 cases (67.0%) were not detected before the operation. The preoperative detection group had a higher median age than the non-detection group [69.0 (58.5, 82.0) years vs 59.0 (55.0, 71.5) years, P=0.026], and a larger hiatal defect area [15.00 (6.00, 16.50) cm² vs 6.00 (4.50, 11.25) cm², P<0.001]. Detection proportion differed significantly between type I and type Ⅱ-Ⅳ HH (P<0.001). Multivariable Firth penalized logistic regression showed higher odds of detection for type Ⅱ-Ⅳ HH than type I HH (OR=8.410, 95% CI: 1.991-48.859; P=0.003). Each 1-cm² increase in hiatal defect area was associated with an 8.4% increase in the odds of detection (OR=1.084, 95% CI: 1.002-1.178; P=0.045). Age, sex, and body mass index were not independently associated with preoperative detection (all P>0.05). Barium esophagography, upper gastrointestinal endoscopy, and thoracoabdominal CT detected HH in 19 (20.2%), 16 (17.0%), and 25 (26.6%) patients, respectively. The overall paired comparison did not reach the statistical significance threshold (Cochran's Q=5.727, P=0.057).

Among the patients who underwent anti-reflux surgery with intraoperatively confirmed HH, HH type and hiatal defect area were independently associated with preoperative detection. Type Ⅰ HH and a smaller hiatal defect area are less likely to be detected before the operation. The overall comparison of the three examinations did not reach the statistical significance threshold.