![Manual vacuum aspirator](https://upload.wikimedia.org/wikipedia/commons/6/60/Manual_vacuum_aspirator.jpg)
Vacuum or suction aspiration is a procedure that uses a vacuum source to remove an embryo or fetus through the
cervix. The procedure is performed to induce
abortion
Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. An abortion that occurs without intervention is known as a miscarriage or "spontaneous abortion"; these occur in approximately 30% to 40% of pregn ...
, as a treatment for incomplete spontaneous abortion (otherwise commonly known as
miscarriage
Miscarriage, also known in medical terms as a spontaneous abortion and pregnancy loss, is the death of an embryo or fetus before it is able to survive independently. Miscarriage before 6 weeks of gestation is defined by ESHRE as biochemical lo ...
) or retained fetal and placental tissue, or to obtain a sample of uterine lining (
endometrial biopsy
The endometrial biopsy is a medical procedure that involves taking a tissue sample of the lining of the uterus. The tissue subsequently undergoes a histologic evaluation which aids the physician in forming a diagnosis.
Medical uses
There are a ...
).
It is generally safe, and serious complications rarely occur.
Some sources may use the terms ''
dilation and evacuation
Dilation and evacuation (D&E) is the dilation of the cervix and surgical evacuation of the uterus (potentially including the fetus, placenta and other tissue) after the first trimester of pregnancy. It is a method of abortion as well as a common ...
''
or "suction" ''
dilation and curettage
Dilation (or dilatation) and curettage (D&C) refers to the dilation (widening/opening) of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping (curettage). It is a gynecolog ...
''
to refer to vacuum aspiration, although those terms are normally used to refer to distinctly different procedures.
History
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 lives.
In Canada, the method was pioneered and improved on by
Henry Morgentaler
Henekh "Henry" Morgentaler, (March 19, 1923 – May 29, 2013), was a Polish-born Canadian physician and abortion rights advocate who fought numerous legal battles aimed at expanding abortion rights in Canada. As a Jewish youth during World War ...
, 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
The Karman cannula is a soft, flexible cannula (or curette) used in medical procedures that was popularized by Harvey Karman in the early 1970s. The flexibility of the Karman cannula was claimed to reduce the risk of perforating the uterus during ...
, 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.
[, which cites:]
:: 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.
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 Cervical dilation (or cervical dilatation) is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery. Cervical dilation may occur naturally, or may be induced surgically o ...
anytime in the first trimester (up to 12 weeks
gestational age
In obstetrics, gestational age is a measure of the age of a pregnancy which is taken from the beginning of the woman's last menstrual period (LMP), or the corresponding age of the gestation as estimated by a more accurate method if available. Su ...
). For more advanced pregnancies, vacuum aspiration may be used as one step in a
dilation and evacuation
Dilation and evacuation (D&E) is the dilation of the cervix and surgical evacuation of the uterus (potentially including the fetus, placenta and other tissue) after the first trimester of pregnancy. It is a method of abortion as well as a common ...
procedure. Vacuum aspiration is the surgical procedure used for almost all first-trimester abortions in many countries, if
medication abortion
A medical abortion, also known as medication abortion, occurs when drugs (medication) are used to bring about an abortion. Medical abortions are an alternative to surgical abortions such as vacuum aspiration or dilation and curettage. Medical ...
is not a viable option .
Procedure
![Vacuum-aspiration](https://upload.wikimedia.org/wikipedia/commons/1/15/Vacuum-aspiration.svg)
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.
[Baird (2001), pp. 4-6.] 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
A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general a ...
(usually
lidocaine
Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lidoca ...
) 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 Cervical dilation (or cervical dilatation) is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery. Cervical dilation may occur naturally, or may be induced surgically o ...
with drugs or
osmotic dilator
Osmotic dilators are medical implements used to dilate the uterine cervix by swelling as they absorb fluid from surrounding tissue. They may be composed of natural or synthetic materials. A laminaria stick or tent is a thin rod made of the stems o ...
s administered before the procedure. Finally, a sterile
cannula
A cannula (; Latin meaning 'little reed'; plural or ) is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or outer surfaces ...
is inserted into the
uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uter ...
. 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
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often dis ...
and suction which empties uterine contents, which either enter a canister or the syringe.
After a procedure for abortion or miscarriage treatment, the tissue removed from the uterus is examined for completeness to ensure that no
products of conception are left behind.
Expected contents include the
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
or
fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal deve ...
, as well as the
decidua
The decidua is the modified mucosal lining of the uterus (that is, modified endometrium) that forms every month, in preparation for pregnancy. It is shed off each month when there is no fertilised egg to support. The decidua is under the influ ...
,
chorionic villi,
amniotic fluid
The amniotic fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus, but also serves to facilitate the exchange of nutrients, water, and biochemical products betwee ...
,
amniotic membrane
The amnion is a membrane that closely covers the human and various other embryos when first formed. It fills with amniotic fluid, which causes the amnion to expand and become the amniotic sac that provides a protective environment for the develo ...
and other tissues. These are all tissues which are found in a normal pregnancy. In the case of a molar pregnancy, these components will not be found.
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
Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
analgesics
that may be started the day before the procedure, as well as
misoprostol
Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. Misoprostol is taken by mouth w ...
the day before for
cervical ripening which makes dilation of the cervix easier to perform.
Procedural sedation and analgesia
Procedural sedation and analgesia (PSA) is a technique in which a sedating/dissociative medication is given, usually along with an analgesic medication, in order to perform non-surgical procedures on a patient. The overall goal is to induce a decr ...
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
Asherman's syndrome (AS) is an acquired uterine condition that occurs when scar tissue (adhesion (medicine), adhesions) forms inside the uterus and/or the cervix. It is characterized by variable scarring inside the uterine cavity, where in many ca ...
, 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.
Vacuum aspiration may be used earlier in pregnancy when compared to sharp D&C. Manual vacuum aspiration is the only surgical abortion procedure available earlier than the sixth week of pregnancy.
Vacuum aspiration, especially manual vacuum aspiration, is significantly cheaper than sharp D&C. The equipment needed for vacuum aspiration costs less than a set of surgical
curette
A curette is a surgical instrument designed for scraping or debriding biological tissue or debris in a biopsy, excision, or cleaning procedure. In form, the curette is a small hand tool, often similar in shape to a stylus; at the tip of the cu ...
s. Additionally, sharp D&C is generally provided only by
physician
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
s, vacuum aspiration may be performed by advanced practice
clinicians such as physician assistants and midwives, which greatly increases access to these services.
[Baird (2001), pp. 5,8-13.]
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.
One of the main complications is retained products of conception which will usually require a second aspiration procedure. This is more common when the procedure is performed very early in pregnancy, before 6 weeks gestational age.
Another complication is infection, usually caused by retained products of conception or introduction of
vaginal flora
Vaginal flora, vaginal microbiota or vaginal microbiome are the microorganisms that colonize the vagina. They were discovered by the German gynecologist Albert Döderlein in 1892 and are part of the overall human flora.
The amount and type of ...
(otherwise known as bacteria) into the uterus. The rate of
infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
is 0.5%.
Other complications occur at a rate of less than 1 per 100 procedures and include excessive blood loss, creating a hole through the cervix or uterus
(
perforation
A perforation is a small hole in a thin material or web. There is usually more than one perforation in an organized fashion, where all of the holes collectively are called a ''perforation''. The process of creating perforations is called perfor ...
) that may cause injury to other internal organs. Blood clots can possibly form within the uterus and block outflow of bleeding from the uterus which can cause the uterus to be enlarged and tender.
References
{{DEFAULTSORT:Vacuum Aspiration
Methods of abortion
Miscarriage