Omegavan is a lipid solution (fat containing solution) that is not currently available in the United States unless the medical institution files for specific exemptions for its use. It is not used in enteral feeding (food given via the intestine), and does not specifically affect absorption by the intestine or intestinal growth. It is not a "new" lipid, as it has been on the market in Europe for some time.
As you have noted, some institutions believe that Omegavan has beneficial properties that exceed the benefits of other lipid formulations. Although there have been interesting clinical reports as well as animal experiments, there has not yet been a large randomized controlled trial to study the benefits/side effects of Omegavan in newborn infants.
Ive heard of omegaven, and i really want to get ahold of some! My G>I doc really likes it but he's in AZ. Have they tried pregestimil, its a pre digested milk formula, made by Enfamil.