Background: A giant hiatal hernia is defined as having greater than 50% of the stomach herniated into the chest. Giant hernias have an increased risk of gastric volvulus causing acute gastric obstruction and strangulation. Controversy exists regarding surgical intervention for asymptomatic giant hiatal hernias. The goals of this study are to determine the number of cases of giant hiatal hernias in a moderate sized Canadian city and to determine the number of cases of giant hiatal hernia referred for surgical assessment and/or needing emergent surgical intervention.

Methods: The Capital Health District diagnostic imaging database, specifically CT, was searched for key words including hiatal hernia, diaphragmatic hernia, paraesophageal hernia, and intrathoracic stomach between Jan. 2010 – Jan. 2015.
Surgical interventions, emergency department encounters and surgical referrals were reviewed using personal health records. 

Results: A total of 357,213 CT chest/abdomen reports were searched yielding 388 patients reported to have a diaphragmatic hernia. Hiatal hernias were identified in185 patients (50.2%). Type III and IV hiatal hernias were reported in 75 patients (40%) including 30 (16.2%) giant hernias. Type IV hernias had the highest percentage of emergency department visits (36.4%). However, only 6 (20%) patients with type III and IV hernias were referred for surgical assessment. Seven (23%) patients with a giant hiatal hernia required emergent repair compare to no patient with a non-giant hernia (p <0.001). However, only 4 (57%) patients with a giant hiatal hernia requiring emergent surgery were referred for elective surgical assessment. 

Conclusion: Congenital and type I hiatal hernias compromise the majority of diaphragmatic hernias. Emergency department encounters and need for emergent surgical intervention were highest among Type III and IV hiatal hernias. Patients with giant hiatal hernia are at increased risk for needing emergent surgery. Patients with Type III and IV hernias, and especially those with a giant hiatal hernia, should be referred for surgical assessment because of an increased risk of needing emergent surgical intervention.

All patients with a giant hiatal hernia require referral to a surgeon.