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),
- extratubal adhesions that may distort the normal course of
the tube within the pelvis.
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 woman's 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
* (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,
- 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
- 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),
- absent fimbria,
- dense adnexal adhesions with fixation of the ovary and tube,
- 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).