Background: Diaphragmatic Hernias (DH) are a known, yet poorly studied, post-surgical complication of esophagectomy. The aim of this study was to analyze the Minimally Invasive Esophagectomy (MIE) experience at a single high-volume academic institution, in order to identify risk factors associated with DH.

Methods: We reviewed data from MIEs performed at our institution (July 2013 - January 2018). Patients who developed a DH at any time post operatively were compared to those who did not. We compared pre-, intra- and postoperative clinical variables of interest in the two groups using Fisher’s exact test for all categorical variables and Mann- Whitney test for continuous variables.

Results: 103 patients underwent MIE during the study period; eight developed DH in a time frame ranging from one week to two years post operatively. All identified DH involved >1 intraabdominal organs other than the stomach; seven patients required reoperation. DH patients appeared to have lower Body Mass Index (BMI) and lower incidence of reported gastroesophageal reflux disease. Furthermore, the DH population tended to have an overall more advanced cancer stage (p=0.028) and a higher incidence of occult microscopically positive margins in the resected specimen (p=0.027). There were no statistically significant differences in intraoperative variables between the two groups, nor where there differences in incidence of postoperative complications other than DH.

Conclusion: DH occurred in approximately 8% of patients undergoing MIE. Lower BMI and more advance cancer stage appear to be significantly associated with DH, perhaps pointing towards more extensive dissection as a potential risk factor.