Ovarian reserve after laparoscopic treatment of unilateral ovarian endometrioma.

AIM: To evaluate the effect of laparoscopic treatment of unilateral ovarian endometrioma on ovarian reserve using ultrasonographic markers, ovarian volume and antral follicle count (AFC), and two biochemical markers, serum levels of Follicle-stimulating hormone (FSH) and Estradiol (E2).
MATERIAL AND METHODS: This prospective study included 40 patients in their reproductive age, between 18 and 40 years old. They were treated laparoscopically for unilateral ovarian endometrioma. Markers of ovarian reserve were investigated before and three months after surgery. Transvaginal ultrasound examination was used for measurement of ovarian volume and AFC. Biochemical markers (FSH and E2 levels) were determined by chemiluminescent tests.
RESULTS: Ovarian volume was significantly reduced after surgery. There was significant increase of AFC and non-significant increase of E2 levels in treated patients after three months.
CONCLUSIONS: Laparoscopic cystectomy of unilateral ovarian endometrioma decreased ovarian reserve immediately after surgery with decrease of ovarian volume. But ovarian reserve was increased after three months with increase of AFC and estradiol levels.

1. INTRODUCTION

Ovarian endometrioma is a benign, estrogen-depending cyst found in 5 to 10% of women in reproductive age. In 20 to 40% it affects women with infertility (1). These women have symptoms as dyspareunia, dysmenorrhea, infertility.

The gold standard for symptomatic women with ovarian endometrioma (diagnostic and therapeutic method) is laparoscopy. Excision (cystectomy) of the cyst is rather recommended because it is associated with a higher pregnancy rate and a lower recurrence rate (2, 3, 4, 5). The most commonly used excision technique is the stripping procedure. It includes stripping of the cystic wall, avoiding removal of the adherent normal ovarian cortex and coagulation for hemostasis. Ovarian reserve is defined as the capacity of the ovary to produce healthy eggs available for maturation and capable for fertilization. It has been reported that ovarian reserve is negatively affected by cystectomy due to removal of normal ovarian tissue (6, 7). The traditional method for evaluation of the ovarian reserve is determination of serum follicle-stimulating hormone and estradiol levels. When ovarian reserve is diminished, the FSH and E2 levels are elevated (8). In clinical practice estimation of the functional ovarian reserve is done with antral follicle count and measurement of ovarian volume. The ovarian volume is calculated with prolate ellipsoid formula (9). Antral follicles are ultrasonographically visible actively growing follicles. They are 2-10 mm in diameter and may be seen and counted with standard transvaginal ultrasonography (10).

This study evaluated the effect of unilateral laparoscopic cystectomy on ovarian reserve. The used markers were ultrasonographical, ovarian volume and antral follicle count, and two biochemical markers, serum levels of Follicle-stimulating hormone and Estradiol.

2. MATERIAL AND METHODS

This prospective study was conducted in the period from 01.01.2012 to 31.12.2013 at the University Clinic for Gynecology and Obstetrics in Skopje, Republic of Macedonia. It included 31 patients with age range from 20 to 40 years. All patients had preoperative ultrasound diagnosis of unilateral ovarian endometrioma. Participants were given written and oral information about the surgery and possible complications, and they signed a consent form. The study protocol was approved by the Ethics and Research Committee of the Medical Faculty in Skopje.

The inclusion criteria were age (between 20 and 40 years) and ultrasonographic findings of unilateral ovarian endometrioma (with mean diameter of 4 cm and more). Indications for surgery were chronic pelvic pain or infertility.

Exclusion criteria were: previous adnexal surgery, history for oral contraceptive pill use or hormonal therapy for the last three cycles, other endocrine diseases such as thyroid disease, hyperprolactinemia, diabetes mellitus or adrenal disorders, patients with histopathologic diagnosis for benign ovarian cysts other than endometrioma and patients with Polycystic ovary syndrome. Transvaginal ultrasound examination of every patient in proliferative phase of menstrual cycle with measurement of three perpendicular diameters was done. Ovarian volume was calculated using “prolate ellipsoid formula”= [D1×D2×D3×0.523], where D1, D2 and D3 were maximal longitudinal, antero-posterior and transverse diameters. AFC was recorded as the total number of follicles with a diameter smaller than 10 mm. Ge Voluson E8 with a 7.5 MHz vaginal probe was used for ultrasound examination.

Analysis of the biochemical markers for ovarian reserve FSH and E2 on day 3 of the menstrual cycle (MC) before surgery was done. FSH-Immulite 2000 test was used for detection of serum levels of FSH. Immulite 2000 test was used for serum levels of estradiol.

Operative laparoscopy was performed during the proliferative phase of the cycle through insertion of a 10 mm subumbilical trocar and two 5 mm trocars in the lower abdomen. After identification of the cleavage plane, the wall of the cyst was stripped from the surrounding healthy ovarian tissue with two atraumatic grasping forceps. Finally, hemostasis was achieved with electrocoagulation with bipolar forceps with a power of 30W. After the operation the tissue was sent for histological examination to confirm the diagnosis of ovarian endometrioma. All patients were examined after three months in the proliferative phase of the cycle for the same parameters.

Statistical analysis

Data were presented as mean value ± SD. Statistical significance (for p < 0.05) of difference between parameters before surgery and three months after laparoscopy was determined using Student’s t-test. For qualitative data were used number and percent. Statistical analyses were performed with Statistics Package for Social Sciences software (SPSS), version 12, for Windows.

3. RESULTS

This study included 31 patients in their reproductive age, between 20–40 years (31 ± 6 years), and BMI with mean values 23 ± 3.6. Laparoscopic stripping surgical method was used. Baseline characteristics of patients with unilateral endometrioma ovarii are presented in Table 1.

Table 1

Baseline characteristics of patients with unilateral ovarian endometrioma. n.s. not significant; values are mean ± SD

Ovarian endometrioma was located on the left ovary in 17 patients (55%) and on the right ovary in 14 (45%). Indications for surgery were chronic pelvic pain in 24 cases (77%) and infertility in 7 (23%) cases.

A significant reduction of ovarian volume after three months was found (p<0.01).

The number of AFC in the treated ovary was significantly increased after three months in comparison with the AFC before surgery (p <0.001).

Serum levels of FSH on the third day of menstrual cycle before surgery were 6.74 ± 4.84 mIU/ml and after three months 5.69 ± 3.30 mIU/ml, which was a non-significant decrease of FSH level. On the other hand, estradiol levels were 120.57±90.88 pg/ml before surgery and 135.52±91.30 pg/ml three months after laparoscopic surgery. There was a slightly non-significant increase of estradiol levels. The results are presented in Table 2.

Table 2

Ultrasonographic and biochemical parameters for ovarian reserve before and three months after laparoscopic cystectomy of ovarian endometrioma.

Endometriom of the right ovary

Endometriom of the left ovary

4. DISCUSSION

Today laparoscopy should be considered as the gold-standard treatment of ovarian endometriomas. There is no ideal technique for this treatment (3). Excision of the cyst is recommended. The cause is a higher pregnancy rate and a lower recurrence rate (4).

According to several studies that reported data on the stripping procedure the removal of the cyst wall may result in removal of healthy ovarian tissue with loss of follicles (2, 3, 4). The study of Muzii et al. demonstrated, by histologic analysis, that some ovarian tissue was removed together with the endometrioma (pseudocapsule) in 54% of the cases (5). Benaglia L. et al. found 13% of severe ovarian damage following laparoscopic surgery for unilateral ovarian endometriomas (11).

The results of Candiani M. et al. showed that laparoscopic cystectomy with electrocoagulation was associated with a significant reduction in ovarian reserve after surgery, which was partially a consequence of the damage of the ovarian vascular system (12). Our study has shown that the ovarian tissue is reduced after surgery. This results are similar with the study of Salem A.H. et al. They found significant reduction in ovarian volume three months after laparoscopic cystectomy because of ovarian endometrioma (13). The significant increase of AFC after three months is similar with the results obtained in the study of Pados et al. They reported an increase of the number of antral follicles six month after laparoscopy (14). FSH levels were decreased after three months follow-up, which showed a good ovarian reserve because the ovary produced more hormones (E2) to inhibit production of FSH. These data are similar with the results of Broekmans FJ et al. (15).

5. CONCLUSION

Laparoscopic surgical treatment of unilateral ovarian endometrioma affected ovarian reserve early after surgery. It led to a significant reduction in ovarian volume. On the other hand, laparoscopic treatment of ovarian endometriomas with stripping increased AFC and estradiol levels after three months. These women had better ovarian function after laparoscopic surgery.