Role of Fertility Preservation With Surgical Interventions
Fertility preservation is an important consideration for women undergoing surgery for ovarian endometriomas, especially for those with existing low ovarian reserve, those at high risk for ovarian dysfunction after surgical intervention, and those who are likely to experience a recurrence of ovarian endometriomas or premature ovarian failure.
There are several reasons as to why fertility preservation should be a priority for patients undergoing surgical intervention for ovarian endometriomas. Surgery is often associated with a loss of ovarian reserve. Somigliana et al. reported a mean reduction in follicular reserve of 53% following laparoscopic cystectomy. This may be the result of the excision of healthy ovarian tissue along with the endometriotic cyst. In fact, follicles were found in 69% of the ovarian tissue close to the ovarian hilus that was inadvertently removed from along the wall of the endometrioma.
Premature ovarian failure is an additional complication associated with invasive surgery. Premature ovarian failure is associated with abnormal amounts of estrogen production and irregular release of oocytes, which can result in infertility. Too much surgery may deplete the ovarian reserve or reduce ovarian function, and too little or incomplete surgery may lead to cyst recurrence. The recurrent cysts may form spontaneously or may develop from the lesions resulting from the surgery. Patients with recurrent endometriomas, especially those experiencing severe pain, may opt for additional surgical procedures to remove the new cysts, which may have a further impact on their fertility. Because surgery for ovarian endometrioma is often associated with postoperative reductions in fertility, preservation and improvement of fertility should be considered before surgical intervention.
Current methods of fertility preservation in patients with ovarian endometriomas include combined surgical techniques; autotransplantation of cryopreserved or fresh, healthy ovarian tissue; and cryopreservation of oocytes or embryos. As previously outlined, Donnez et al. recently developed a new surgical method combining both excisional and ablative techniques. This procedure allows for complete excision of the cyst without removing or damaging healthy ovarian tissue in the process, in order to avoid recurrence of the endometrioma and protect the ovarian reserve. This option is likely best for women with a high chance of spontaneous conception after surgery or those patients who wish to avoid the use of ART to achieve a pregnancy.
Autotransplantation of cryopreserved or fresh ovarian tissue is another potential option for patients undergoing surgical intervention for endometriomas. Donnez et al. reported a case study of two women with severe endometriosis who underwent oophorectomy immediately followed by heterolateral orthotopic transplantation of fresh ovarian cortex tissue. Viable primordial follicles were found in both cases, and revascularization of the transplanted tissue was demonstrated by the presence of a network of many small vessels. This procedure helps increase the follicular reserve of the remaining or unaffected ovary.
In 2010, Oktay et al. conducted a follow-up with 59 female cancer patients who had undergone ovarian tissue cryopreservation between May 1997 and March 2008. Of these women, 5.1% had chosen to reimplant the harvested tissue, and one woman was able to spontaneously achieve a pregnancy. The study concluded that ovarian tissue cryopreservation and transplantation appear to be a safe and relatively effective procedure, but evidence is limited due to the low clinical utilization of the technique. Ovarian tissue autotransplantation is the best option for women undergoing radical oophorectomy, with a high likelihood of recurrence after conservative surgery or when the remaining healthy ovarian tissue may be compromised.
Oocyte and embryo cryopreservation are effective methods of fertility preservation for patients with ovarian endometriomas. Recent improvements in oocyte freezing thawing using both slow freezing and vitrification techniques, and a growing body of evidence that these techniques are successful, have expanded the potential use of this process as a method of fertility preservation. Embryo cryopreservation is currently the only established method of fertility preservation in women, as oocyte and ovarian tissue cryopreservation remain experimental techniques. However, embryo cryopreservation requires the patient to have a partner. Oocyte cryopreservation offers more flexibility, as IVF can be used with either donor or a partner's sperm when a woman desires to become pregnant in the future. As outlined previously, ovarian endometriomas are associated with reductions in oocyte quality, and further research is needed to determine the potential effectiveness of oocyte cryopreservation as a fertility preservation measure in women with endometriomas. Oocyte and embryo cryopreservation are especially useful methods for women with low ovarian reserve, and should be considered the first line of treatment for patients with a high risk of premature ovarian failure following surgical intervention for ovarian endometriomas.
Fertility preservation is recommended as a part of pre-operative counseling for young patients with endometriosis. Along with the guidance of their surgeons, women should carefully consider each method of fertility preservation before undergoing surgery for ovarian endometrioma, and decide which option fits best with their plans for fertility in the future.
Expert Rev of Obstet Gynecol. 2013;8(1):29-55. © 2013 Expert Reviews Ltd.