We didn’t always do it this way but when we started to sew in layers, we noticed that the dye we test the tube with flowed a lot better. Most people who do tubal reversals just sew around the outside of the tube to bring the two pieces together. They claim the extra time and expense is not necessary. They may be right, no one knows for sure. This is why some clinics do 5-8 procedures a day and we do only 1-2.
The middle layer of the tube is muscular. It makes sense that it is a muscle for a reason. It may play a role in propelling the egg down the tube or it may let the tube move around to capture the egg when it is released from the ovary.
There have been studies that show that the tube moves around when a woman has an orgasm. The muscle layer has to be involved in this movement and it stands to reason that it may play a role in conception.
When you sew all layers together with one stitch you create an unnatural adhesion between the inner and outer layer. The outer layer is loosely attached to the muscular layer in the natural state and we feel that it’s important to not change that. Again, we have no argument with what others may or may not do.