Residual Ovary Syndrome - Types, Causes, Risk Factors, Diagnosis and Treatment

What Is Oophorectomy?

Oophorectomy is the term that describes the surgical removal of one or both ovaries. Oophorectomy is otherwise known as ovariectomy. When one ovary is removed, then it is known as a unilateral oophorectomy. Removal of both ovaries is known as bilateral oophorectomy. Oophorectomy can also be done as a part of an operation that involves the removal of the uterus (hysterectomy). This surgical procedure is done for several reasons. Oophorectomy is used to treat pelvic inflammatory disease (a bacterial infection affecting reproductive organs), endometriosis, chronic pelvic pain, ectopic pregnancy, benign tumors, and large ovarian cysts. In the case of women carrying mutations of BRCA1 or BRCA2 genes, oophorectomy can be performed to lower the risk of ovarian cancer. This procedure is known as an elective or prophylactic oophorectomy. Both estrogen and progesterone hormones are produced from the ovaries. Removal of both ovaries results in menopause and permanent infertility.

What Is Residual Ovary Syndrome?

Residual ovary syndrome (ROS) occurs when pieces of ovarian tissue are left in the body after a woman undergoes surgery to remove one or two ovaries (oophorectomy). It is also known as ovarian remnant syndrome (ORS). These ovarian remnants can also re-implant themselves in the abdominal cavity, including the bladder, bowel, and ureters. This retained tissue can develop into a cyst or bleeding, causing pain. Several factors cause this condition. The specific signs and symptoms observed are pelvic pain, formation of a pelvic mass, and absence of menopause after undergoing oophorectomy. Treatment is given for women experiencing symptoms and involves removing remnant tissue by surgery.

What Is the Cause of Residual Ovary Syndrome?

The risk of residual ovary syndrome increases by incomplete removal of ovarian tissue at the time of oophorectomy. Several factors contribute to the incomplete removal of ovarian tissue. The crucial causes are pelvic adhesions, anatomical variations, and poor surgical procedures.

Adhesions are scar tissue bands that make the organs fuse or get stuck together. Pelvic adhesions often result from previous surgeries or pre-existing conditions such as endometriosis (a disorder in which endometrium, the lining of the uterus, grows outside the uterus). Adhesions may cause difficulty for the surgeon in identifying and removing ovaries because adhesions bind with other structures of the ovary or peritoneum (a serous membrane that lines the walls of the abdominal cavity).

Anatomical variations occur when ovaries remain located in unusual locations. Endometriosis also increases the risk of having remnant ovarian tissues because these remnants may stay embedded in the adjacent structures and make complete excision of remnant tissues challenging. Finally, these remnant ovarian tissues remain unremoved. The risk of ROS also increases when an unskilled or inexperienced surgeon performs ovariectomy.

What Are the Risk Factors of Residual Ovary Syndrome?

Most patients develop residual ovary syndrome when they have a previous history of endometriosis or any other previous illness-causing pelvic adhesions. Residual ovary syndrome also occurs in patients with partial or faulty oophorectomy procedures.

What Are the Symptoms of Residual Ovary Syndrome?

1. Pelvic Pain Years After Hysterectomy: This is one of the classic symptoms of residual ovary syndrome.
2. Cyclic Pain: The other symptoms are cyclic pelvic pain that coincides with the menstrual cycle and the formation of a pelvic mass.
3. Menstrual Problems: The main symptom of residual ovary syndrome is a lack of menopause and continuous production of estrogen and progesterone following oophorectomy.
4. Sexual Problems: Some women may also experience painful intercourse, difficulty in urination, and painful bowel movements.
5. Pelvic Mass: An abnormal pelvic mass can be seen on pelvic imaging and examination.

These symptoms usually occur within the first five years of oophorectomy. In rare cases, ROS may also happen after twenty years of oophorectomy. There is an estimated amount of at least five percent of women who face this issue after a hysterectomy procedure.

How to Diagnose Residual Ovary Syndrome?

Residual ovary syndrome is often diagnosed in women with a previous history of oophorectomy followed by specific symptoms such as pelvic mass or persistent ovarian function. The doctor needs to know the reason behind the oophorectomy. It is necessary to know whether the affected person had endometriosis or prior abdominal or pelvic surgery and poor surgical visualization due to the poor anatomical location of the ovaries. The doctor may also advise a pelvic ultrasound to know the presence of a pelvic mass in ROS. Surgical exploration and biopsy of the remnant ovarian tissue will help confirm the ROS diagnosis. Excision of the remnant ovarian tissue may also be done using the same procedure. For women who have not undergone prior abdominal surgery, the clinical diagnosis of ROS is based on the symptoms, hormone levels, and imaging. The doctor may also advise the affected women to do an ultrasound, CT (computed tomography) scan, or MRI (magnetic resonance imaging) to diagnose the cause.

How to Treat Residual Ovary Syndrome?

Treatment for residual ovary syndrome is given based on the patient's symptoms. The mainstay of treatment involves surgery to remove residual ovarian tissue. Women having ROS with a pelvic mass need appropriate evaluation for malignancy. Hormonal therapy to suppress ovarian function is the alternative treatment for women who refuse surgery or patients who are unadvisable for surgery. These ovarian remnants do not respond well to hormonal therapy in some cases. In such cases, laparoscopic surgery helps to remove ovarian remnants. Though this surgery remains challenging due to the scar tissues formed from previous surgeries, the improved visualization and accessibility provided by laparoscopy make removing remnants possible.

What Are the Preventive Measures to Be Taken to Avoid Residual Ovary Syndrome?

Residual ovary syndrome is a rare condition. However, it often develops in patients who had imprecise or incomplete surgery to remove one or both ovaries. Early surgical treatment of endometriosis might reduce the occurrence of pelvic adhesions, which makes incomplete removal of ovarian tissues more likely. The physician's skill in undergoing ovary removal surgery also plays an essential role in developing residual ovary syndrome.

What Are the Risks Faced When Residual Ovary Syndrome Is Left Untreated?

In certain circumstances, residual ovary syndrome does not cause any symptoms and can be left untreated as it does not lead to any severe effects. But rarely, an untreated residual ovary syndrome can result in the formation of cysts that cause severe pelvic pain.

Conclusion

Since residual ovary syndrome is rare, regular follow-up after an oophorectomy by consulting a doctor is enough to prevent this condition. If one has undergone an oophorectomy procedure and experiences pain years later, an immediate medical consultation is advised. Residual ovary syndrome is a preventable surgical complication if detected early.