Introduction: The current system for classifying paraesophageal hernias is based on the herniated contents and the location of the gastroesophageal (GE) junction in relation to the diaphragmatic hiatus. While this system represents a basic anatomic description of the hernia, there is little clinical relevance to aid in pre-operative or intra-operative management. New imaging technology permits the study of these hernias in 3-dimensions, providing an understanding of their anatomy at a greater level of detail and relevance to the clinician.
Methods: 24 patients who underwent laparoscopic paraesophageal hernia repair were reviewed. Pre-operative CT scans were reconstructed using a unique protocol with semi-automatic segmentation. Reconstructions permitted analysis of the geometry of hiatal defects and herniated contents. Patients were categorized by hiatal shape, angulation of herniated contents, and the location of the herniated stomach. These groupings were then compared to patient outcomes, specifically, need for Collis gastroplasty, need for buttress of hiatus repair, gastrostomy, and intra-operative complications.
Results: Analysis revealed four distinct defect morphologies. The geometry of the herniated contents was described according to the amount of stomach situated in the chest, and by the angle formed by three anatomic structures: the GE junction, the base of the diaphragmatic crura, and the antrum (the “PEH angle”). Symmetric defects less often required gastric fixation, but were more likely to need a Collis gastroplasty. The mean PEH angle was 87°. Patients requiring an esophageal lengthening had a mean angle of 82°, compared to 100° in those who did not. Stomach location also influenced operative events, as evidenced by a 57% incidence of intra-operative complications such as enterotomies and liver injuries in patients with a stomach equally above and below the diaphragm, compared to 15% in those with the stomach mostly above, and 0% in those with the stomach mostly below (p = .106, Fisher Exact Test).
Conclusion: Paraesophageal hernias remain a significant management challenge. Patients and surgeons alike stand to benefit from highly detailed pre-operative information on hernia anatomy and visceral relationships. Combining advances in imaging and computing power, we propose a novel classification system based on advanced reconstruction techniques, which allows us to view these challenging surgical problems in ways not previously possible with fluoroscopy or even CT alone. Key anatomic features and relationships identified by these means can aid in pre-operative decision making and patient counseling, and predict operative difficulty.