P&S Journal: Spring 1994, Vol.14, No.2
Transvaginal Ultrasound-Guided Ovarian Cyst Aspiration
By Robin Eisner
As part of the trend in health care to reduce the length of hospital stays, decrease medical costs, and minimize patient discomfort, P&S clinicians now treat certain women's benign ovarian cysts during an office visit with a two-minute, ultrasound-guided needle aspiration procedure.
The cysts, fluid-filled sacs about 7 centimeters in diameter, are a common cause of ovarian enlargement that requires medical attention.
Many physicians in the United States treat ovarian cysts primarily with more invasive methods, such as laparoscopy (endoscopic surgery) or laparotomy (surgery). But in the past three years, 75 women treated at CPMC have been spared surgical procedures to treat their ovarian cysts. They have three physicians to thank for the transvaginal ultrasound-guided procedure and cyst diagnosis: Dr. Ilan Timor, professor of clinical obstetrics and gynecology; Dr. Jodi Lerner, assistant clinical professor of obstetrics and gynecology; and Dr. Ellen Greenebaum'77, associate professor of clinical pathology.
Ovarian cysts require attention because some of them can twist or rupture, bleed, and create a medical emergency. Other cysts that persist can interfere with normal ovarian function and impair a woman's ability to conceive by producing hormones that prevent normal egg release from the ovary, for example.
In the procedure, the physician, usually a gynecologist, first places an ultrasound probe attached to an automated and retractable needle puncture device into the patient's vagina. Ultrasound enables the sonographer to detect density differences between tissue and fluid inside the pelvic area. Guided by the sonographic images, the physician advances the needle through the vaginal wall into the ovary to drain fluid from a cyst. Both the physician and patient can watch the cyst collapse on a TV-video monitor. No pain-killer or sedation is necessary during the procedure, which takes a couple of minutes. Dr. Greenebaum, a cytopathology specialist, then centrifuges the aspirated fluid, smears and stains the cellular sediment, and performs a microscopic examination of the cells to characterize the cyst as a benign or malignant neoplasm or not a neoplasm at all. By comparison, in the outpatient procedure of a laparoscopy for ovarian cysts, a patient is given general anesthesia, the operation is done in an operating room, and the patient needs several hours to recover. Laparotomy is an inpatient surgical procedure necessitating a hospital stay of several days.
Conventionally, transvaginal ultrasound-guided aspiration is used to collect eggs for in vitro fertilization or to reduce the number of viable fetuses in multifetal gestations. Only recently has transvaginal ultrasound-guided aspiration been employed to treat benign ovarian cysts. Some physicians resist using the method because they are concerned about potential problems arising from aspirating cancerous rather than benign cysts. Drs. Timor and Lerner, however, have developed a scoring system to help distinguish a non-cancerous from a cancerous cyst.
If the cyst appears thin and smooth-walled and contains a liquid that is sonolucent (meaning it appears clear with ultrasound), the physicians assume it is non-cancerous so they collapse it and collect the fluid. If the cyst looks cancerous because it has inclusions or invaginated walls, the clinicians recommend a laparotomy because the abdomen and pelvis must be fully explored and any cancerous organs removed. They do not aspirate these cysts because leakage of fluid-containing cancerous cells into the peritoneal cavity could theoretically seed the growth of the tumor to previously unaffected areas in the body.
Drs. Lerner, Timor, and Greenebaum have years of experience and data confirming ultrasound diagnoses with pathological studies. The benign cysts treated with this procedure often are either follicular or corpus luteal cysts. Follicular cysts occur when the chosen follicle (a group of cells that surround the egg) within the ovary fails to release its egg and continues to swell and collect fluid within the ovary or on its surface. Corpus luteal cysts result from an irregularity in the progesterone-producing corpus luteum, the burst follicle on the ovary's surface that contained the egg. Increased progesterone levels could prevent normal ovarian function.
There are other cysts, although benign, that are not ideal for needle aspiration. These include cysts that are endometriotic (relating to ectopic growth of the uterine endometrium in or near the ovary) or neoplastic but benign, such as serous or mucinous cystadenomas or benign cystic teratomas (cysts derived from epithelium in which secretions accumulate). If fluid including these abnormal but benign cells were to spill from these cysts, the benign cells could cause abdominal cavity irritation. So far the P&S clinicians have had few problems with fluid leakage. The majority of women with ovarian cysts who undergo this procedure have been referred. Typically, a patient reports abdominal pain, her physician feels a mass during an internal examination, or the cyst is seen in a routine ultrasound during an in vitro fertilization workup.
One problem with the transvaginal ultrasound procedure is that fluid reaccumulates in up to 30 percent of the cases. This necessitates repetition of the procedure or a different treatment. In the majority of cases, though, women are spared an invasive procedure.
Dr. Timor predicts that more women will benefit from this procedure as ultrasound imaging improves and more research correlates cyst type with prognosis.