There are some locations where it is extremely difficult to achieve a good seal, especially with gauze kits. The popularity of foam for NPWT is certainly partly related to the fact that it is often easier to achieve a good seal. However there are a couple of tips for increasing the probability of a seal. 

The first tip is just good skin degreasing. The transparent film dressing will adhere to the skin much better when the skin is properly prepared. Most of you who regularly apply wound vac dressings already know this.

Here is the tip that some of you may not know about. There is a product made by Devon that is a hydrogel strip. If you apply a series of overlapping strips around the wound bed prior to the application of the transparent film dressing, you will find these strips will enable seals even when there is an irregular surface. It is pretty ingenious how Devon has managed to produce these strips in such a way that makes them so easy to apply. (Removing them? Not quite so easy.) You can find the Devon silicon gel strips here.