Ovarian drilling is a surgical technique of puncturing the membranes surrounding the ovary with a laser beam or a surgical needle using minimally invasive laparoscopic procedures. It differs from ovarian wedge resection, because resection involves the cutting of tissue. Minimally invasive ovarian drilling procedures have replaced wedge resections. Ovarian drilling is preferred to wedge resection because cutting in to the ovary can cause adhesions which may complicate postoperative outcomes. Ovarian drilling and ovarian wedge resection are treatment options to reduce the amount of androgen producing tissue in women with Polycystic Ovarian Syndrome (PCOS). PCOS is the primary cause of anovulation, which results in female infertility. The induction of mono-ovulatory cycles can restore fertility.
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Laparoscopic ovarian drilling may improve the effectiveness of other ovulation induction treatments and results in lower multiple pregnancy rates than other treatment options like gonadotropins. The oral drug, clomiphene citrate (CC), is the first-line treatment for PCOS, yet, one fifth of women are resistant to the drug and fail to ovulate. Ovarian drilling is a surgical alternative to CC treatment or recommended for women with WHO Group II ovulation disorders. The effectiveness of the surgical procedure is similar to CC or gonadotropin treatment for induced ovulation for PCOS patients, but results in fewer multiple pregnancies per ongoing pregnancy regardless if the technique is unilaterally or bilaterally performed.
Hormonal Effects
The procedure causes a drop in serum androgen levels and possibly in estrogen levels. After ovarian follicles and stroma are destroyed, there is a reduction in these hormone levels. The most plausible theory states that the reduction of these hormone concentrations leads to an increase in the secretion of follicle-stimulating hormone (FSH) and effective follicular maturation and ovulation. Inflammatory growth factors such as insulin-like growth factor-1 are produced due to injury and aid the effects of FSH through greater blood flow and gonadotropin delivery.
Procedures
When the clinician determines that ovarian drilling is appropriate and the woman decides to undergo this treatment, consent is obtained. The risks are communicated to the woman.
The most commonly performed method is with a monopolar needle or hook because of the equipment's availability and simple installation. Other common instrumentation consists of the use of a bipolar electrical surgical electrodes or a CO2, argon, or ND-YAG laser. This instrumentation has the ability to produce the intended results with a very focal approach. The surgical punctures are performed on the ovarian cortex and are usually 4-10 mm deep and 3 mm wide. The number of punctures is related to subsequent ability to conceive—it has been found that five to ten punctures are more likely to produce the intended conception.
Risks
Though preferable to creating incisions on the ovary, ovarian drilling does have some risks. These are: pelvic adhesion formation, premature ovarian failure, long-term ovarian function, developing hyperstimulation syndrome, adhesion formation, infertility and multiple births.
Advantages
Ovarian drilling has lower rates of ovarian hyperstimulation syndrome and of multi-fetal gestation. The advantages of the procedure also include its singular treatment, as opposed to several trials of ovulation inductions. Other benefits of this technique include cost-effectiveness and that it can be performed as an outpatient procedure.
History
Ovarian drilling was first used in the treatment of PCOS in 1984 and has evolved as a safe and effective surgery. After performing laparoscopic electrosurgical ovarian drilling in CC-resistant patients, Gjönnaess found that this technique increased ovulation rates to 45 percent and pregnancy rates to 42 percent.