Effects of cystectomy on ovaries

The ovaries are very important for female friends. They mainly play the role of ovulation. If the ovaries are abnormal, problems such as menstrual disorders, amenorrhea or vaginal dryness will occur, and severe cases can lead to infertility. Therefore, protecting the health of the ovaries is very important for us. Some women may experience symptoms due to ovarian problems, such as chocolate cysts. So what should they do?

Epidemiological surveys on endometriosis show that the incidence rate is 7.5%-10%, most commonly in women aged 25-35 years, with 0.1% of new cases every 5 years in women aged 15-49 years. Women with endometriosis have decreased fertility, 25%-50% of patients are infertile, and 17%-44% of patients have pelvic masses (endometriosis cysts).

Pathological types of ovarian endometrial cysts (chocolate cysts)

Type I: The cyst diameter is less than 2 cm, the cyst wall is adhered, the anatomical layers are unclear, and it is difficult to remove it surgically;

Type II: It is further divided into 3 subtypes;

IIA: The endometrial implants are superficial, involving the ovarian cortex, not reaching the ratio of ovarian endometriosis cysts, often combined with functional cysts, and easy to remove during surgery;

IIB: The endometrial implants have already involved the wall of the ovarian endometriosis cyst, but the boundary with the ovarian cortex is clear and it is easier to remove during surgery;

IIC: The endometrial implants penetrate the wall of the ovarian endometriosis cyst and expand to the surrounding area. The cyst wall is tightly adhered to the ovarian cortex and is accompanied by fibrosis or multilocular cavities. The cyst is adhered to the pelvic side wall and is large in size, making it difficult to remove during surgery.

The ovaries have the potential to produce eggs in certain quantity and quality. The ovarian reserve function depends on the quantity and quality of stored follicles in the ovaries. Assessing ovarian function has important clinical significance for predicting reproductive potential and ovarian functional status. Diminished ovarian reserve means that the number of eggs remaining in the ovaries drops to a threshold (critical value), thus affecting reproductive potential and leading to decreased fertility. As women age, the number and quality of follicles decrease, which is called physiological decreased ovarian reserve. Non-physiological decreased ovarian reserve includes unexplained decreased ovarian reserve, which may be caused by ovarian surgery, radiotherapy, chemotherapy, disease, etc.

Methods for assessing ovarian reserve

1. Hematology: Early follicular phase blood FSH, estradiol, ovarian inhibin B, blood anti-Mullerian hormone (AMH).

2. Basic antral follicle number and ovarian volume.

Advantages of AMH in evaluating ovarian function

1. AMH comes from preantral follicles and granulosa cells of small antral follicles, and can reflect the age-related decline in ovarian reserve function earlier and more accurately.

2. AMH levels do not change significantly within or between cycles, and blood can be drawn for testing at any time during the cycle.

3. AMH is maintained at a relatively consistent level between the ages of 18 and 29 (20-50 pmol/L, 2.85-3.57 ng/ml).

4. It starts to decline after the age of 30, and drops to 10pmol/L (1.43ng/ml) at the age of 37. At this time, FSH has no obvious changes. AMH is a good indicator for evaluating ovarian function and can predict the decline of ovarian function earlier.

Surgical treatment of ovarian chocolate cyst

1. Cyst removal: when the cyst diameter exceeds 4cm;

2. Cyst wall cauterization: cyst incision, fluid aspiration or extraction, bipolar electrocoagulation or CO2 laser;

3. Cyst fluid aspiration: It is usually performed during egg retrieval. It has a high recurrence rate, increases the chance of infection, and may cause the cyst fluid to contaminate the eggs.

The first choice for surgery for cystic cyst is cystectomy. Laparoscopic resection of cystic cysts larger than 4 cm can better improve fertility than drainage and cauterization. Failure to remove the pseudocapsule of the cystic cyst will increase the recurrence rate of the cyst. A study on whether ovarian cyst surgery affects ovarian function found that ovarian cyst removal reduced the antral follicle count (AFC) of the affected ovary, but the AFC of the affected ovary was lower than that of the normal control ovary before surgery. Therefore, more sensitive indicators such as AMH are needed to predict ovarian function. Another study used AMH as an evaluation indicator and found that AMH decreased significantly before and after surgery. Therefore, it is believed that ovarian cyst surgery affects ovarian reserve function by significantly reducing AMH.

Another report pointed out that the decrease in AMH before and after cyst surgery is related to age. The older the age, the more obvious the decrease. The decrease is more obvious in bilateral cyst surgery than in unilateral surgery. A retrospective analysis of endometriosis with AMH < 1ng/ml showed that AMH was lower in women over 35 years old and those who smoked. Another factor was cyst surgery. Ovarian endometrioma cystectomy affects ovarian responsiveness in the IVF cycle, such as increasing the dosage of Gn, reducing the number of retrieved eggs, the number of high-quality embryos, and the number of embryos that can be frozen, which has a certain adverse effect on IVF-ET, but has no significant effect on IVF pregnancy outcomes.

Analysis of the reasons why the chocolate cyst itself affects ovarian function

The pathogenesis of endometriosis:

1. Menstrual blood countercurrent, coelomic epithelial metaplasia, vascular and lymphatic metastasis theory and stem cell theory;

2. Based on Sampson's retrograde menstrual blood theory, the endometrium that flows back to the pelvic cavity needs to go through the processes of adhesion, invasion, and vascularization to implant, grow, and develop lesions;

3. The characteristics of the resident endometrium play a decisive role, which is called the "resident endometrium theory".

Theory of the mechanism of decreased ovarian function in women with cystic ovary:

Occult cysts originate from the invagination of lesions on the surface of the ovary and the metaplasia of the epithelium on the invaginated ovarian surface. The above theories indicate that the cystic tissue comes from the ovarian cortex, causing inflammatory reactions and subsequent fibrosis. Oxidative stress has been reported in the ovarian tissue surrounding ovarian cysts, which is responsible for follicle loss. In vitro studies have shown that oxidative stress induces oocyte apoptosis and necrosis of premature follicles. A biopsy of 20 cases of cystic cysts showed that the follicle density of the ovarian cortex of cystic cysts <4 cm was lower than that of the contralateral normal ovary, and fibrosis appeared on the affected ovary while there was no such phenomenon on the normal side, indicating that the cystic cyst itself was associated with decreased ovarian function.

Surgical treatment of ovarian chocolate cysts:

More than 90% of chocolate cysts are attached with nearby ovarian tissue during removal. The size of the cyst and intraoperative electrocoagulation have an impact on ovarian function. A 2002 study on the presence of ovarian tissue accompanying ovarian cyst removal found that in 26 cases of ovarian cyst removal, ovarian tissue was visible in 14 cases; another study on the size of ovarian cysts and surgical damage to the ovaries found that the larger the cyst, the greater the impact on ovarian function; a study on the effect of ovarian cyst removal or electrocoagulation on ovarian function showed that electrocoagulation has a great impact on ovarian function, including bipolar electrocoagulation, and for young patients with ovarian cysts, electrocoagulation should be avoided as much as possible during surgery; a study comparing the thickness of the cyst wall after removal of cysts by experienced surgeons and residents in laparoscopic training showed that the thickness of the removed cyst wall was related to the surgeon's experience.

Necessity of surgery and prevention of damage to ovarian function:

Surgery is an effective treatment for ovarian cysts. A cyst with a diameter exceeding 4 cm is an indication for surgery. Surgical treatment can remove the lesion (cyst), effectively relieve pain symptoms, improve fertility, and have a postoperative pregnancy rate of 45%-52%, reducing the risk of ovarian cancer.

Treatment of recurring cysts:

The recurrence rate of lesions after conservative EM surgery ranges from 6.1% at 18 months to 36.5% within 2 years, and as high as 50% 5 years after surgery. Young people who need to preserve their fertility can undergo surgery or ultrasound-guided puncture, postoperative drug treatment or assisted reproductive technology. For older patients or those whose imaging examinations indicate that there is a solid part or obvious blood flow in the cyst, surgery is appropriate. Repeated surgeries may further reduce ovarian reserve function and increase the risk of premature ovarian failure.

Precautions during cystectomy:

1. Surgeon requirements: Laparoscopic surgery should be performed by physicians with certain experience and surgical skills. It is not recommended for beginners to perform this type of surgery.

2. Evaluate ovarian function before surgery;

3. Minimize the loss of normal ovarian tissue during the operation, distinguish the anatomical layers, the boundary between the cyst wall and normal ovarian tissue, and preserve the residual ovarian tissue as much as possible;

4. Maintain good ovarian blood supply. Ovarian cysts are prone to occur near the ovarian hilum. During surgery, the incision should avoid the ovarian hilum and the suture density should not be too dense to avoid affecting the ovarian blood supply.

5. Avoid electrocoagulation. Energy devices, especially monopolar electrocoagulation, have a great impact on the ovaries.

Surgical exploration of ovarian chocolate cysts has been conducted abroad to reduce the impact on ovarian function. For cysts with a diameter of more than 5 or 6 cm, the cyst wall is first incised and flushed with saline. After using GnRHa for 3 months, surgery is performed again to vaporize the cyst wall (the cyst wall becomes thinner and thermal damage is reduced). There have also been recent reports that when removing the cyst wall, the cyst wall away from the ovarian hilum is removed, and the cyst wall of the ovarian part is left behind and vaporized to preserve the ovarian tissue as much as possible.

summary

Ovarian chocolate cysts (endometrial cysts) themselves may indicate decreased ovarian function. Surgery is an effective treatment for chocolate cysts, but it has adverse effects on ovarian function. A full evaluation should be conducted before surgery, and emphasis should be placed on clear anatomical layers during surgery to reduce the loss of ovarian tissue, avoid electrocoagulation and the effect on ovarian blood supply. The surgeon should be a physician with experience in laparoscopic surgery and chocolate cyst surgery.