Suction-aspiration abortion
Encyclopedia
Vacuum or suction aspiration uses aspiration to remove uterine contents through the cervix
. It may be used as a method of induced abortion
, a therapeutic procedure used after miscarriage
, or a procedure to obtain a sample for endometrial biopsy. The rate of infection
is lower than any other surgical abortion procedure at 0.5%. 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 distinct procedures.
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 Karnen in the United States refined the technique 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.
When used as a miscarriage treatment or an 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 procedure used for almost all first-trimester abortions in many countries.
is created with either an electric pump (electric vacuum aspiration or EVA) or a manual pump (manual vacuum aspiration or MVA). Both methods use the same level of suction, and so can be considered equivalent in terms of effectiveness and safety.
The clinician may first use a local anesthetic
to numb the cervix
. Then, the clinician may use instruments called "dilators" to open the cervix, or sometimes medically induce dilation with drugs. Finally, a sterile cannula
is inserted into the uterus
and attached via tubing to the pump. The pump creates a vacuum
which empties uterine contents.
After a procedure for abortion or miscarriage treatment, the tissue removed from the uterus is examined for completeness. Expected contents include the embryo
or fetus
as well as the decidua
, chorionic villi, amniotic fluid, amniotic membrane
and other tissue.
Post-treatment care includes brief observation in a recovery area and a follow-up appointment approximately two weeks later.
(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 D&C and has largely replaced D&C in many settings.
Vacuum aspiration may be used earlier in pregnancy than dilation and curettage
(D&C). Manual vacuum aspiration is the only surgical abortion procedure available earlier than the 6th week of pregnancy. Vacuum aspiration has lower rates of complications when compared to D&C.
Vacuum aspiration - especially manual vacuum aspiration - is significantly cheaper than D&C. The equipment needed for vacuum aspiration costs less than a curette
set. Unlike D&C, vacuum aspiration does not require general anesthesia and so can be performed as an outpatient procedure at a clinic rather than in a hospital surgical setting. While D&C is generally provided only by physician
s, vacuum aspiration may be performed by mid-level health care providers such as physician's assistants and midwives.
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 noise of an electric vacuum pump.
Other complications occur at a rate of less than 1 per 100 procedures and include excessive blood loss, infection, injury to the cervix or uterus, including perforation
, and uterine adhesions.
Cervix
The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall...
. It may be used as a method of induced abortion
Abortion
Abortion is defined as the termination of pregnancy by the removal or expulsion from the uterus of a fetus or embryo prior to viability. An abortion can occur spontaneously, in which case it is usually called a miscarriage, or it can be purposely induced...
, a therapeutic procedure used after miscarriage
Miscarriage
Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving independently, generally defined in humans at prior to 20 weeks of gestation...
, or a procedure to obtain a sample for endometrial biopsy. The rate of infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
is lower than any other surgical abortion procedure at 0.5%. Some sources may use the terms dilation and evacuation
Dilation and evacuation
Dilation and evacuation literally refers to the dilation of the cervix and surgical evacuation of the contents of the uterus...
or "suction" dilation and curettage
Dilation and curettage
Dilation and curettage refers to the dilation of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping . It is a diagnostic gynecological procedure.D&C normally is referred to a procedure involving a curette, also called sharp...
to refer to vacuum aspiration, although those terms are normally used to refer to distinct 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 that "ultimately led to the technique becoming the world’s commonest and safest obstetric procedure".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 Karnen in the United States refined the technique 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 a therapeutic procedure after miscarriage, to aid in menstrual regulation, and to obtain a sample for endometrial biopsy. It is also used to terminate molar pregnancy.When used as a miscarriage treatment or an abortion method, vacuum aspiration may be used alone or with cervical dilation
Cervical dilation
Cervical dilation is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery...
anytime in the first trimester (up to 12 weeks gestational age
Gestational age
Gestational age relates to the age of an embryo or fetus . There is some ambiguity in how it is defined:*In embryology, gestational age is the time elapsed since conception. This interval is also termed fertilisation age....
). For more advanced pregnancies, vacuum aspiration may be used as one step in a dilation and evacuation
Dilation and evacuation
Dilation and evacuation literally refers to the dilation of the cervix and surgical evacuation of the contents of the uterus...
procedure. Vacuum aspiration is the procedure used for almost all first-trimester abortions in many countries.
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. SuctionSuction
Suction is the flow of a fluid into a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Suction is popularly thought of as an attractive effect, which is incorrect since vacuums do not...
is created with either an electric pump (electric vacuum aspiration or EVA) or a manual pump (manual vacuum aspiration or MVA). Both methods use the same level of suction, and so can be considered equivalent in terms of effectiveness and safety.
The clinician may first use a local anesthetic
Local anesthetic
A local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
to numb the cervix
Cervix
The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall...
. Then, the clinician may use instruments called "dilators" to open the cervix, or sometimes medically induce dilation with drugs. Finally, a sterile cannula
Cannula
A cannula or canula is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of data...
is inserted into the uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
and attached via tubing to the pump. The pump creates a vacuum
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
which empties uterine contents.
After a procedure for abortion or miscarriage treatment, the tissue removed from the uterus is examined for completeness. Expected contents include the embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
or fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
as well as the decidua
Decidua
Decidua is the term for the uterine lining during a pregnancy, which forms the maternal part of the placenta. It is formed under the influence of progesterone and forms highly-characteristic cells.-Etymology:...
, chorionic villi, amniotic fluid, amniotic membrane
Amniotic sac
The amniotic sac is the sac in which the fetus develops in amniotes. It is a tough but thin transparent pair of membranes, which hold a developing embryo until shortly before birth. The inner membrane, the amnion, contains the amniotic fluid and the fetus. The outer membrane, the Chorion,...
and other tissue.
Post-treatment care includes brief observation in a recovery area and a follow-up appointment approximately two weeks later.
Advantages over dilation and curettage
Dilation and curettageDilation and curettage
Dilation and curettage refers to the dilation of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping . It is a diagnostic gynecological procedure.D&C normally is referred to a procedure involving a curette, also called sharp...
(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 D&C and has largely replaced D&C in many settings.
Vacuum aspiration may be used earlier in pregnancy than dilation and curettage
Dilation and curettage
Dilation and curettage refers to the dilation of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping . It is a diagnostic gynecological procedure.D&C normally is referred to a procedure involving a curette, also called sharp...
(D&C). Manual vacuum aspiration is the only surgical abortion procedure available earlier than the 6th week of pregnancy. Vacuum aspiration has lower rates of complications when compared to D&C.
Vacuum aspiration - especially manual vacuum aspiration - is significantly cheaper than D&C. The equipment needed for vacuum aspiration costs less than a curette
Curette
A curette is a surgical instrument designed for scraping 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 curette is a small scoop, hook, or gouge...
set. Unlike D&C, vacuum aspiration does not require general anesthesia and so can be performed as an outpatient procedure at a clinic rather than in a hospital surgical setting. While D&C is generally provided only by physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
s, vacuum aspiration may be performed by mid-level health care providers such as physician's assistants and midwives.
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 noise of an electric vacuum pump.
Complications
When used for uterine evacuation, vacuum aspiration is 98% effective in removing all uterine contents. Retained products of conception require a second aspiration procedure. This is more common when the procedure is performed very early in pregnancy, before 6 weeks gestational age.Other complications occur at a rate of less than 1 per 100 procedures and include excessive blood loss, infection, injury to the cervix or uterus, including perforation
Uterine perforation
Uterine perforation is a potential complication of any intrauterine procedure. It may be associated with injury to surrounding blood vessels or viscera such as the bladder or intestine. If not diagnosed at the time of the procedure it can result in massive hemorrhage or sepsis...
, and uterine adhesions.