Alvimopan in Enhanced Recovery Colorectal Surgery?
Recently, Adam et al1 published a retrospective review of their data from a nonrandomized setting with or without use of alvimopan in colorectal surgery. Alvimopan was associated with faster return of bowel function, shorter length of stay (mean reduction by 1.6 days from 9.8 to 8.5 days) and major cost savings. It was concluded that “alvimopan is cost-effective within an enhanced recovery colorectal surgery protocol and should be considered in these programs.”
A closer look at the article may not justify this conclusion for several reasons. First of all, it was retrospective and nonrandomized and without specific information on the indication for alvimopan. Secondly, there was a pronounced skewness in distribution of the time of the procedures in which most of the controls came from an earlier time period than the alvimopan group. Thus, the results may have been influenced by an improvement in the implementation of the enhanced recovery program, but where we get no data. Importantly, we get no information on the specific use, composition, and site of the epidural analgesia, which may influence ileus duration. Even more important, we get no information on the perioperative use of opioids in the 2 groups and where alvimopan is supposed to be effective only when using opioids. Finally, there was also a skewness in the type of procedures with a tendency toward more “easy” procedures in the alvimopan group.
Although a statistical exercise with multivariate analysis was employed, but not discussed in detail, there may be too many important confounders to allow their conclusion,1 also compared to other published data from fully implemented enhanced recovery programs without alvimopan.