Vacuum Aspiration: Clinical Overview, History, and Procedure

Vacuum or suction aspiration is a procedure that uses a vacuum source to remove an embryo or fetus through the cervix. It is generally safe, and serious complications rarely occur. Some sources may use the terms dilation and evacuation or "suction" dilation and curettage to refer to vacuum aspiration, although those terms are normally used to refer to distinctly different procedures.

Clinical Uses and Applications

Vacuum aspiration may be used as a method of induced abortion as well as a therapeutic procedure after spontaneous abortion. The procedure is performed to induce abortion, as a treatment for incomplete spontaneous abortion (otherwise commonly known as miscarriage) or retained fetal and placental tissue, or to obtain a sample of uterine lining (endometrial biopsy). It is also used to terminate molar pregnancy. When used as a spontaneous abortion management or as a therapeutic abortion method, vacuum aspiration may be used alone or with cervical dilation anytime in the first trimester (up to 12 weeks gestational age). For more advanced pregnancies, vacuum aspiration may be used as one step in a dilation and evacuation procedure.

The procedure can also aid in regulation of the menstrual cycle and to obtain a sample for endometrial biopsy. A study found use of Karman vacuum aspiration to be a safer option for endometrial biopsy when compared to the alternatives such as conventional endometrial curettage. Vacuum aspiration is the surgical procedure used for almost all first-trimester abortions in many countries, if medication abortion is not a viable option.

Global Usage and Statistics

Usage figures for the procedure, which covers a gestation period of 3-13+6 weeks, are recorded as follows:

• Sweden: 42.7% (2005)
• UK (Eng. & Wales): 64% (2006)
• United States: 59.9% (2016)

Note: Figures represent the combined usage of MVA and EVA.

History and Development

Vacuuming as a means of removing the uterine contents, rather than the previous use of a hard metal curette, was pioneered in 1958 by Drs Wu Yuantai and Wu Xianzhen in China. It is now known to be one of the safest obstetric procedures, and has saved countless women's lives. In Canada, the method was pioneered and improved on by Henry Morgentaler, achieving a complication rate of 0.48% and no deaths in over 5,000 cases. He was the first doctor in North America to use the technique, which he then trained other doctors to use.

In Europe and the US, Dorothea Kerslake introduced the method into the United Kingdom in 1967 and published a study in the United States that further spread the technique. Later, Harvey Karman in the United States refined the technique in the early 1970s with the development of the Karman cannula, a soft, flexible cannula that avoided the need for initial cervical dilatation and so reduced the risks of puncturing the uterus.

The Procedure

Vacuum aspiration is an outpatient procedure that generally involves a clinic visit of several hours. The procedure itself typically takes less than 15 minutes. Depending on the state of residence and local laws, two appointments and various other proceedings may be required if the vacuum aspiration is being used for therapeutic abortion.

Suction Sources: EVA and MVA

There are two options for the source of suction in the use of these procedures. Suction can be created with either an electric pump (electric vacuum aspiration or EVA) or a manual pump (manual vacuum aspiration or MVA). A hand-held 25cc or 50cc syringe can function as a manual pump. Both of these methods can create the same level of suction, and therefore are considered equivalent in terms of efficacy of treatment and safety. The difference in use primarily comes down to provider preference.

Clinical Execution

To begin the process, the clinician places a speculum into the vagina in order to visualize the cervix. The cervix is cleansed, then a local anesthetic (usually lidocaine) is injected in the form of a para-cervical block or intra-cervical inject.