[1] The flexibility of the Karman cannula was claimed to reduce the risk of perforating the uterus during vacuum aspiration.
[2] Both Karman's procedure, menstrual extraction, and his cannula were embraced by activists Carol Downer and Lorraine Rothman, who modified the technique in 1971 and promoted it.
[3] The "self-help" abortion movement envisioned by Downer and Rothman never entered the mainstream in the U.S. before or after Roe v. Wade.
In 2010, a Sri Lankan physician named Geeth Silva was the first physician to use the Karman cannula in the removal of impacted faeces from a patient; this was done in Columbo at the Sri Jayawardenepura General Hospital.
Physicians and other health care providers sometimes use a Karman cannula in "menstrual regulation" vacuum aspiration procedures in developing countries where abortion is illegal (e.g.