In vivo measurement of esophageal hiatus surface area using MDCT: description of the methodology and clinical validation

Purpose Accurate estimation of esophageal hiatus surface area (HSA) prior to surgical repair of hiatal hernia is difficult. The ability to do so may assist with following progression of hiatal hernias, choosing the optimal surgical approach and post-surgical evaluation. We developed a method for measurement of HSA using multi-planar reconstruction (MPR) of multi-detector computed tomography (MDCT) scans and sought to validate our method using intra-operative HSA measurements. Methods Patients with thoracic or abdominal CT scans who were scheduled to undergo hiatal hernia repair were identified. A radiologist performed MPR of each MDCT scan to obtain the measured HSA (mHSA). Estimated HSA (eHSA) was obtained using intra-operative measurements of crura length and distance between crural edges. The association between eHSA and the corresponding mHSA was assessed using Pearson correlation. The intra-class correlation coefficient was calculated to assess both intra-observer and inter-observer agreement for the MDCT–MPR technique. Results Of 30 subjects included, 16 (53.3%) were female and the median age was 68.5 years. All patients underwent robotic-assisted laparoscopic hiatal hernia repair. The median HSA was 8.1 cm 2 based on intra-operative measurements and 9.9 cm 2 based on CT measurements. The correlation coefficient for eHSA and corresponding mHSA was 0.83 ( p < 0.001). The intra-class correlation coefficient was 0.97 ( p < 0.001) for intra-observer agreement and 0.97 ( p < 0.001) for inter-observer agreement. Conclusion We developed a MDCT–MPR technique that measures HSA in vivo. This technique is reproducible and can be used for pre-operative planning and post-operative follow-up of patients with symptomatic hiatal hernia.