Vacuum aspiration

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, but their paper was only translated into English on the fiftieth anniversary of the study which would ultimately pave the way for this procedure becoming exceedingly common. 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. Dorothea Kerslake introduced the method into the United Kingdom in 1967 and published a study in the United States that further spread the technique. 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. ==Clinical uses==

Vacuum aspiration may be used as a method of induced abortion as well as a therapeutic procedure after spontaneous abortion. 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. 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. Vacuum aspiration is the surgical procedure used for almost all first-trimester abortions in many countries, if medication abortion is not a viable option . ==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. 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. 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 injection into the cervix. The clinician may use instruments called "dilators" in incrementally larger sizes to gently open the cervix, or medically induce cervical dilation with drugs or osmotic dilators administered before the procedure. Finally, a sterile cannula is inserted into the uterus. The cannula may be attached via tubing to the pump if using an electric vacuum, or attached directly to a syringe if using a manual vacuum aspirator. The pump creates a vacuum and suction which empties uterine contents, which either enter a canister or the syringe. Post-treatment care includes brief observation in a recovery area and a follow-up appointment approximately two weeks later. During these visits, it is possible that the provider may perform tests to check for infection, as retained tissue in the uterus can be a source of infection. Additional medications used in vacuum aspiration include NSAID analgesics Procedural sedation and analgesia may be offered to the patient in order to avoid discomfort. ==Advantages over sharp dilation and curettage==

Sharp dilation and curettage (D&C), also known as sharp curettage, was once the standard of care in situations requiring uterine evacuation. However, vacuum aspiration has a number of advantages over sharp D&C and has largely replaced D&C in many settings. Manual vacuum aspiration has been found to have lower rates of incomplete evacuation and retained products of conception in the uterus. Sharp curettage has also been associated with Asherman's Syndrome, whereas vacuum aspiration has not been found to have this longer term complication. Overall, vacuum aspiration has been found to have lower rates of complications when compared to D&C. Manual vacuum aspiration does not require electricity and so can be provided in locations that have unreliable electrical service or none at all. Manual vacuum aspiration also has the advantage of being quiet, without the louder noise of an electric vacuum pump, which can be stressful or bothersome to patients. ==Complications==

When used for pregnancy evacuation, vacuum aspiration is 98% effective in removing all uterine contents. ==References==