Variables affecting the results of xenogenic collagen implantation in an animal model.

A number of variables that can affect the results of xenogenic collagen implantation were studied by means of the pig model. Zyderm Collagen Implant was analyzed biochemically and was used to study the following variables: injection volume, collagen concentration, injection intervals, and needle gauge. The results of the study revealed the following: Injection volumes of 0.125 to 0.25 ml given at the same site resulted in the appearance of large "pools" of Zyderm Collagen Implant in the subcutaneous fat. However, injection volumes of 0.0625 to 0.1 ml given at the same site resulted in all of the implant's being retained in the dermis. There was no appreciable difference in the results achieved with two different concentrations of implant. Serial reinjections of 0.1 ml at 1-week intervals revealed increased amounts of implant material in the dermis. The use of a 30-gauge needle allowed more superficial placement than was possible with a 27-gauge needle.