As I prepare for residency applications I am increasingly thinking back on the people who supported my journey through medicine thus far. Among these was my Cancer Metastasis professor who supported my pre-med journey both academically and emotionally. Her particular passion was the sharing of information regarding the omentum and so in honor of her, I have decided to use this platform to do so briefly.
Despite its discovery, in the 19th century, the omentum’s structure and function continue to be ill elucidated. As a consequence of this dearth of research, it is primarily characterized as a peritoneal organ responsible for storing the fat in our belly. It is further reviled for releasing chemicals that stimulate the onset of high blood pressure, high cholesterol, and diabetes. This simplistic interpretation presented most notably by Mehmet OZ does an enormous disservice to both the omentum and to the variety of fields it impacts by underestimating and obscuring its vital importance. When granted the proper respect and depth of analysis the omentum quickly reveals itself to be an extremely dynamic structure with vital functions both biologically and clinically. Among the best-characterized aspects of the omentum is its ability to facilitate post-surgical recovery by promoting vascularization of graft tissue and adhering to sites of wound healing. This role occurs endogenously as well as readily adhering to areas of inﬂammation and peritoneal damage, often leading to adhesion formation. In addition, the omentum serves as both a reservoir for peritoneal inflammatory cells along with its much-reviled role as a storage site for lipids. A final critical function of the omentum is as a regulator of fluid exchange in and out of the peritoneal cavity. The omentum is of interest pathologically as well given its ability to attract ovarian cancer metastasis, a phenomenon warranting further study. Even from this cursory analysis, we see that the elucidation of the omentum’s full nature has the potential to yield enormous benefits across a variety of medical specialties.
Impressive as it is functionally and medically perhaps the strongest evidence of the omentum’s importance is the degree of evolutionary conservation that it displays. To look at the omentum is to be given a front-row seat to the unity and diversity of life. Species as varied as Rats, Guinea Pigs, mice, rabbits, dogs, pigs, cats, cows, bats, moles, frogs all possess omenta. The omentum is wholly absent in all fish species, however, all other vertebrate groups manifest the organ to varying degrees. The “simplest” organism to display a readily apparent omentum is the giant salamander. While it may not be relevant I find it very interesting that the omentum’s development parallels that of lungs and other adaptations for terrestrial life. The omentum of reptiles though not as well developed as that of mammals, is well-known in veterinary literature as parasites that tend to invade the organ. Here again, we see a strange parallel between the ability of the omentum to attract inflammatory cells, cancer cells, and exogenous parasites. Avian omenta like those of reptiles are not very well-developed. The notable exception is predatory birds that manifest fairly robust omentum, an adaptation theorized to better facilitate the consumption of meat. The omentum is fairly well-developed in all mammals. Given that the development of the omentum closely follows that of undeniably vital organs such as the lungs this analysis of comparative anatomy should serve to underscore the import of the organ in question.