What is the minimum width of fallopian tubes?

Question
What is the minimum width required for the proper functioning of the fallopian tubes? If the width is lesser than that required, how can it be treated?
Expert Answer
I
The lumen of fallopian tube near the uterus is 1 mm and gradually increases up to 2-3 mm towards the fimbrial end without any constriction in between. There is no method to increase the lumen.