Distal tubal occlusion can occur with any chronic inflammatory process within the pelvis that causes irritation and eventual scarring. Examples of such processes include
- infections of the pelvis (PID),
- infectious processes near the pelvis (appendicitis),
- prior pelvic or lower abdominal surgery,
- presence of foreign bodies in the pelvis, and
Damage most significant for fertility includes
- destruction of the delicate tissues and folds that line the inside of the fallopian tubes (the mucosa and rugae),
- occlusion of the distal end of the fallopian tube,
- dilatation of the fallopian tube with the presence of an inflammatory liquid (exudate) within the
- lumen of the tube (hydrosalpinx), and
- extratubal adhesions that may distort the normal course of the tube within the pelvis.
Available Case Reports:
Infectious diseases involving the reproductive organs (PID) can rapidly destroy the reproductive function of these organs. Typically, infectious or chronic inflammatory processes involving the adnexae (ovaries and fallopian tubes) initially result in distal (away from the body of the uterus) obstruction of the tube and damage to the tissues within the tube.
In a classic series of reports by the Swedish gynecologist Dr. L. Westrom, women with laparoscopically confirmed PID suffered from tubal factor infertility relatively rapidly. Westrom reported a 10-15% incidence of infertility after 1 episode, a 20-25% incidence after 2 episodes and a 50-55% incidence after 3 episodes. The risk of infertility following an episode of PID was seen to relate to the womanís age (presumably young women may delay medical intervention), number of infections and the severity of infection. Additionally, there was a 6-10 fold increase in the ectopic (extra uterine) pregnancy rate following an episode of PID.
When the distal portion of the fallopian tube is completely blocked (occluded) in the presence of chronic inflammation then the egg and sperm cannot meet within the tube. If both tubes are blocked then the patient is infertile. If one tube is blocked and dilated while the other tube appears non-dilated and patent on HSG then there still remains a high chance of damage to the open tube since any inflammatory process within the reproductive structures usually affects both sides.
There is very little useful information available to base decisions concerning the approach to distal tubal disease. There is a multi-year study from Johns Hopkins Medical School of 95 women without apparent cause for infertility other than distal tubal disease with obstruction. This study correlated pregnancy rates following surgery to open the tubes with differing degrees of tubal disease. These clinicians report an 80% pregnancy rate if mild disease, 30-35% pregnancy rate if moderate disease and 15-20% pregnancy rate if severe disease. The definition of mild, moderate, and severe disease in this report includes:
1) Mild disease
absent or small (less than 15 mm diameter) hydrosalpinx (dilatation),
easily recognized fimbria (the delicate finger like structures emerging from the distal end of the tube) that were inverted prior to repair (reopening of the distal tube),
absence of significant peritubal or periovarian adhesions, and
normal rugae of the inner tube on HSG.
(2) Moderate disease
a hydrosalpinx with a 15-30 mm diameter,
fragments of fimbria that are not easily recognized,
periovarian or peritubal adhesions without fixation of these structures,
minimal adhesions in the cul de sac behind the uterus, or
absence of tubal rugae on HSG.
(3) Severe disease
large hydrosalpinges (greater than 30 mm diameter),
dense adnexal adhesions with fixation of the ovary and tube, or
obliteration of the cul de sac behind the uterus
There are several reports of improvement in IVF pregnancy rates after removal of hydrosalpinges (dilated tubes). The widely accepted belief is that liquid within the blocked dilated fallopian tubes has no alternative but to pass into the uterine cavity and the presence of this fluid disrupts the ability of an embryo to implant. If the hydrosalpinges are opened surgically then this fluid can pass into the pelvis rather than back into the uterus. However, one should emphasize that surgically opened tubes have a chance of reclosing (roughly proportional to the degree of damage prior to the surgery).