Ectopic pregnancy effects on the ipsilateral fallopian tube epithelium--an ultrastructural study

A Review: Biomechanical Aspects of the Fallopian Tube Relevant to its Function in Fertility

The fallopian tube (FT) plays a crucial role in the reproductive process by providing an ideal biomechanical and biochemical environment for fertilization and early embryo development. Despite its importance, the biomechanical functions of the FT that originate from its morphological aspects, and ultrastructural aspects, as well as the mechanical properties of FT, have not been studied nor used sufficiently, which limits the understanding of fertilization, mechanotrasduction, and mechanobiology during embryo development, as well as the replication of the FT in laboratory settings for infertility treatments. This paper reviews and revives valuable information on human FT reported in medical literature in the past five decades relevant to the biomechanical aspects of FT. In this review, we summarized the current state of knowledge concerning the morphological, ultrastructural aspects, and mechanical properties of the human FT. We also investigate the potential arising from a thorough consideration of the biomechanical functions and exploring often neglected mechanical aspects. Our investigation encompasses both macroscopic measurements (such as length, diameter, and thickness) and microscopic measurements (including the height of epithelial cells, the percentage of ciliated cells, cilia structure, and ciliary beat frequency). Our primary focus has been on healthy women of reproductive age. We have examined various measurement techniques, encompassing conventional metrology, 2D histological data as well as new spatial measurement techniques such as micro-CT.

Effect of hormonal manipulation on human fallopian tubal epithelium in vitro

PURPOSE

Estradiol (E2) induced ciliogenesis has been demonstrated in several mammalian species. There is no consensus as to what extent, if any, this occurs in humans. The aim of this study was to determine whether hormonal manipulation could limit deciliation and/or stimulate ciliogenesis using human tubal epithelium in vitro.

MATERIALS AND METHODS

Experiment 1: Tubal epithelial organ explant cultures were established from nine women undergoing hysterectomy. Several segments from each tube were fixed immediately (in vivo control), the remainder were maintained in culture for one week. One group received no hormontal treatment (in vitro control). The others were supplemented with E2 2 ng/ml (low E2) or 10 ng/ml (high E2), Clomiphene citrate 300 ng/ml + low E2 (CC), and progesterone 300 ng/ml + low E2 (P4). All specimens were examined by scanning electron microscopy and the percent ciliated area determined. Experiment 2: Tubal epithelial cultures were established from an additional 11 patients. After 1 week in culture, half of the explants from each patient were supplemented with E2 15 ng/ml vs no E2 and maintained for another week. The specimens were examined as above, as well as with transmission electron microscopy (TEM).

RESULTS

Experiment 1: After 1 week in culture the mean percent ciliated areas in the in vitro control (24.8 +/- 17.9), low E2 (24.7 +/- 17.0), P4 (20.7 +/- 10.7), and CC (25.8 +/- 17.2) were approximately half the in vivo control (45.7 +/- 10.4), P = 0.005. The high E2 group (39.7 +/- 19.7) was significantly higher than the in vitro control, P = 0.008, but was not different from the in vivo control. Experiment 2: Both groups demonstrated a great reduction in ciliated area and were not significantly different from each other, E2 (8.3 +/- 10.8) and control (3.0 +/- 3.0). TEM failed to demonstrate ciliogenic precursors in either group.

CONCLUSIONS

High E2 was capable of preventing initial epithelial deciliation in vitro. Once deciliation started however, high E2 was unable to limit the process or induce ciliogenesis.

Ectopic pregnancy: its relationship to tubal reconstructive surgery

Ectopic pregnancy is the shady companion of tubal surgery. Among patients with ectopic pregnancy, relatively few have a history of tubal surgery as their underlying etiologic factor when compared with other etiologies such as PID. Nevertheless, a history of tubal surgery should place the patient at a higher-risk group for ectopic pregnancy; 3% to 20% of these patients will encounter an ectopic pregnancy after the corrective surgery. The incidence of ectopic pregnancy after tubal surgery is extremely variable and is closely linked to the degree of restoration of normal functional and anatomic integrity after the surgical procedure. This depends, to a large extent, on the amount of previous damage to the tube and its potential reversibility. Major improvements in surgical technique can, therefore, have reduced, but not eliminated, the occurrence of tubal pregnancy. The incidence of ectopic pregnancy associated with any given tubal surgical procedure should be taken into consideration when surgery is contemplated. When the risk of ectopic pregnancy is unacceptably high, or when the patient is reluctant to be exposed to a high risk of ectopic pregnancy, IVF-ET could be offered as an alternative. Table 11 represents the incidence of ectopic pregnancy associated with the various surgical procedures. The figures demonstrate the wide variation in outcome for the same procedure.