The accessory fallopian tube: A rare anomaly.

This paper presents a rare anatomical variation in the form of accessory fallopian tube on right side. The duplication of fallopian tube was observed in a 34-year-old female during routine undergraduate dissection in our department. Fallopian tube is the part of uterus that carries the ovum from the ovary to the uterus. Accessory fallopian tube is the congenital anomaly attached to the ampullary part of main tube. This accessory tube is common site of pyosalpinx, hydrosalpinx, cystic swelling and torsion. The ovum released by the ovary may also be captured by the blind accessory tube leading to infertility or ectopic pregnancy. Hence, all patients of infertility or pelvic inflammatory disease should be screened to rule out the presence of accessory fallopian tube and if encountered should be removed.

INTRODUCTION

The fallopian tube is 10-12 cm in length, extends from the ovaries to the uterus and has four parts from medial to lateral side: Intramural, isthmic, ampullary and fimbrial. Its main function is to transport the ovum from ovary to the uterus.[1] The accessory fallopian tubes are congenital and developmental Mullerian duct abnormality of the fallopian tube.[12] These are non-patent cylindrical structured attached to the ampullary part of a normal-sized tube. The accessory fallopian tubes are one of the main contributory factors of infertility as their fimbria pick the ovum instead of fimbria ovarica of normal tube.[23] Ectopic pregnancy, cystic swelling and pyosalpinx are other complications related to accessory fallopian tubes.[4-6] Accessory fallopian tubes are rare developmental anomalies resulting from bifurcation of cranial ends of Mullerian ducts, which normally develops into fallopian tube.[7] Knowledge of such rare variations in the fallopian tube is essential for gynecologists in the treatment of infertility and pelvic inflammatory diseases.

CASE REPORT

We found duplication of fallopian tube on right side in a 34-year-old female cadaver during routine dissection of medical undergraduate students in our department. The accessory tube was attached to the ampullary portion of the right main fallopian tube and was tortuous in nature. The lateral end showed presence of fimbria similar to that of main tube. Histologically, the lumen of accessory tube was obliterated at its junction with the main tube. The right ovary was enlarged and polycystic in nature. On the left side, the fallopian tube and ovary was observed as normal [Figure 1].

Figure 1

Partial accessory fallopian tube was observed on right side which was arising from the ampullary portion of main fallopian tube. Black arrow – main fallopian tube, white arrow – accessory fallopian tube

DISCUSSION

The incidence of duplication of fallopian tube was first described by Krossman et al. in 1894 in 4-10% of all women. Since then, many authors reported the anatomy, histology and pathogenesis of accessory fallopian tubes illustrated in Table 1.[3]

Table 1

Comparison between studies on the percentage of prevalence of accessory fallopian tube

Beyth and Kopolovic discussed the phenomenon of infertility in patients having accessory fallopian tube. They emphasized on the fact that the ova may be captured by the fimbria of this accessory tube in spite of the main fallopian tube. And as the accessory tube is obliterated at its attachment with the main tube, the ova is wasted leading to infertility.[3] In case fertilization occurs, this leads to ectopic pregnancy, another life-threatening complication.[6] Pyosalpinx in left accessory fallopian tube was briefly described by Macnaughton almost a century ago. The torsion of the right fallopian tube is more common, because the left tube is fixed in the left hemipelvis by the sigmoid colon and mesentery.[1] Ectopic pregnancy within the accessory tube leading to excessive bleeding and surgical intervention is widely described in literature.[4]

Hence, all the patients of infertility should be screened to rule out the presence of accessory fallopian tube and if encountered should be removed microsurgically to prevent emergency and further life-threatening consequences.