Type II hiatal hernias: do they exist or are they actually parahiatal hernias?

Background: Type II hiatal hernias (HH) are characterized by a portion of the gastric fundus located above the esophageal hiatus adjacent to the esophagus while the gastroesophageal junction (GEJ) remains fixed below the esophageal hiatus. This type of HH has been called the "true" paraesophageal hernia (PEH) because the fundus appears to the side of the esophagus. In our experience, Type II HHs are occasionally identified on radiographic testing, however they are rarely, if ever, confirmed intraoperatively. This led to our question: Does Type II HH exist?

Methods: We searched for evidence of type II HH in three locations: 1. Retrospective review of all first-time PEH repairs (excluding Type I HHs and re-operative cases) performed at the University of Washington Medical Center from 1994 to 2021; 2. Operative videos available on YouTube and WebSurg websites; and 3. Abstracts from the SAGES annual meetings from 2005 to 2021.

Results: We found no evidence of Type II HH in any of our three searches. We performed 846 PEH repairs: 760 Type III, 75 Type IV, and 11 parahiatal. Upon website video review, we found only one possible type II hernia, though it too was likely a para-hiatal hernia. No video or case presentations of a type II HH were identified within SAGES annual meeting abstracts.

Conclusion: Type II HHs do not exist as they are currently defined. Although uncommon, parahiatal hernia can easily be misinterpreted as Type II HH. We should consider changing the hiatal hernia classification system to prevent ongoing clinical confusion.