An unusual laparoscopic finding

A 45 year old woman who had had two normal vaginal deliveries at term had a laparoscopic sterilisation. Fig 1 shows a finding seen in the procedure.

Questions

(1) What does the picture in Fig 1 show? What is the significance of the asterisks and arrows?

Fig 1 This was taken during the laparoscopic sterilisation

(2) Can you recall the important congenital abnormalities of the uterus?

(3) What complications can be associated with these uterine abnormalities?

(4) Can other systems be involved as well? If so, how?

(5) How would you manage the situation?

Answers

(1) The figure shows a congenital abnormality of the uterus. The asterisks indicate the two uterine horns, and the arrows denote the two Filshie clips applied to the fallopian tubes for sterilisation.

(2) Failure of the Müllerian ducts to fuse can lead to several uterine malformations (see fig 2):

Fig 2 Uterine abnormalities (adapted from Pitkin et al)

Unicornuate - Where one of the Müllerian ducts fails to develop resulting in a single uterine horn.

Bicornuate - Both ducts form but one duct develops to a greater extent than the other. Consequently a small "rudimentary horn" exists, which may end blind or be continuous with the dominant horn. There is usually only one cervix.

Double - Complete failure of fusion of the Müllerian ducts. As a result of the independence of the ducts, two uteri develop, each with their own cervix. In addition one or two vaginas may be found.

Septate - Both ducts develop but they only partially fuse. This leaves a septum at the fundus.

In this case, two uterine horns were seen at laparoscopy. Bimanual and speculum examinations found a single cervix, indicating that the patient has a bicornuate uterus.

(3) The two horns of a bicornuate uterus are separated by a median septum. This alters the shape of the uterus. As a result, women present with primary infertility, recurrent miscarriage, and menstrual dysfunction (oligomenorrhoea, dysmenorrhoea, or menorrhagia). Most patients are asymptomatic, and the abnormality is usually only discovered when the woman becomes pregnant. In the second and third trimesters, she can have an increased risk of late abortion, intrauterine fetal death, premature labour, and strange fetal lie (malpresentations or transverse lies resulting from limited movement). A handy acronym we've thought of to remember this is LIPS.

The altered shape of the uterus allows the placenta to develop on the septum resulting in a reduced blood supply, which is detrimental to fetal health. The fetal lie is determined where the maximal room is available to accommodate the baby's hindquarters. With a bicornuate uterus, however, the fetus may fit better with the hindquarters lower in the pelvis. So there's a higher incidence of malpresentations.

(4) Other systems associated with this include renal anomalies-more specifically unilateral agenesis. This is usually only discovered once a diagnosis of Müllerian duct anomalies has been established and renal imaging is pursued because of the strong association of the two conditions.

(5) The septa can be resected hysteroscopically, and rudimentary horns need open removal. Hysteroscopic transection of a uterine septum can be done on a "same day surgery" basis; it has minimal surgical risk; and the postoperative recovery period is generally a few days. Laparotomy with reconstruction of the uterine wall for a bicornuate uterus requires a hospital stay of a few days; it has relatively low surgical risk; and the postoperative recovery period is about six weeks. Current research is inconclusive on the benefits of correcting these congenital abnormalities because success is limited by uterine weakness and the formation of adhesions. To reduce the incidence of premature labour, prophylactic cerclage with progesterone and antispastic therapy has been advocated to improve the obstetric outcome.¹

Discussion

The woman did not present with the recognised symptoms described above, and her uterine anomaly was only discovered incidentally. In fact she had had two normal vaginal deliveries at term and had just been sterilised. A further renal ultrasound scan and intravenous pyelography confirmed the presence of a single kidney, which is a urinary tract abnormality known to be associated with Müllerian duct malformation. This case highlights the fact that although a minority of women with uterine anomalies may present with late abortion, intrauterine fetal death, or premature labour, most stay asymptomatic and are detected incidentally.

To make the distinctions discussed in question (2) clearer, it is important to revise the embryological development of the uterus.

Two Müllerian ducts (also called paramesonephric ducts) form in the 8th week of gestation. These are responsible for the formation of the female reproductive tract-the fallopian tubes, uterus, cervix, as well as the upper two thirds of the vagina.

There are three stages of development.

Organogenesis - This is the first stage involving the development of the Müllerian ducts. At first both the male and the female have two pairs of genital or sex ducts: the mesonephric (Wolffian, medial) and paramesonephric (Müllerian, lateral) ducts. Gonadal sex is determined by the Y chromosome. In the presence of a Y chromosome, an inducer is produced that stimulates the development of the mesonephric ducts into the male genital ducts. A suppressor (Müllerian inhibiting substance) is also produced by the testes, this inhibits the development of the paramesonephric ducts. In the absence of a Y chromosome and, therefore, the presence of two X chromosomes, no inducer or suppressor is produced, so the mesonephric ducts regress, and the paramesonephric ducts develop. The superior end of these paramesonephric ducts open into the future peritoneal cavity and the lower end develops into the uterus and uterine tubes.

Fusion of the Müllerian ducts - The two ducts fuse from the lower segment upwards. Lower segment fusion is called "lateral fusion" and results in the formation of the uterus, cervix, and upper vagina. This is followed by "vertical fusion," where the fused Müllerian ducts join the sinovaginal bulb (which forms the lower third of the vagina) to form a patent vagina. The female reproductive system is completed with the development of the ovaries, which are formed from the germ cells that migrate from the yolk sac.

Septal resorption - Once the Müllerian ducts have fused, a central septum separating the two ducts remains. For a patent uterine cavity to be established, and for the cervix to form, the septum is resorbed.

These women must be managed in a sensitive way because congenital malformations of the genital tract have significant long term sequelae. They affect a woman's psychological, sexual, and reproductive health.

Make sure to first confirm the diagnosis. This can be done using the following techniques:

• Pelvic examination - Can two horns be palpated?
• Laparoscopy - What is the shape of the exterior of the uterus?
• Hysteroscopy - What is the shape of the interior of the uterus?

Explain to the patient the findings clearly. A bicornuate uterus is a uterus that has two horns and a heart shape. The uterus has a wall inside and a partial split outside.

Metroplasty is a surgical procedure used to reshape the uterus and uterine cavity. Cervical cerclage is a procedure used to temporarily stitch the cervix closed in pregnancy, to prevent the cervix from opening too early in pregnancy.

It is important to tackle the woman's concerns of infertility, reassuring her that uterine malformations are found in about 4.3% of the general population of fertile women, in about 3.5% of infertile women, and in about 13% of patients with recurrent pregnancy loss. This shows that a malformed uterus in itself is not a risk factor for infertility. In patients with symptoms, surgery restores an almost normal prognosis of outcome of live birth rates of about 85%.³

1. Leo L, Arduino S, Febo G, Tessarolo M, Lauricella A, Wierdis T, et al. Cervical cerclage for malformed uterus. Clin Exp Obstet Gynecol 1997;24: 104-6.
2. Pitkin J, Peattie A, Magowan B. Developmental and paediatric gynaecology. In: Obstetrics and gynaecology: an illustrated colour text. 1st ed. London: Churchill Livingstone, 2003: 89-92.
3. Grimbizis G, Campus M, Bontis JN, Devroey P. Clinical implications of uterine malformations and hysteroscopic treatment results. Hum Reprod Update 2001;7: 161-74.