Introduction
Early pregnancy loss (miscarriage) occurs in about 10-20% of clinically recognised pregnancies and accounts for more than 50,000 inpatient admissions in the NHS on a yearly basis.1 Although expectant and medical management are increasingly becoming popular, surgical management is still the most commonly performed method of treatment, with up to 88% of miscarrying women undergoing surgical evacuation under general anaesthesia.2 Surgical management is done by curettage (either sharp or suction method). Manual vacuum aspiration (MVA) is a suction technique which utilises self-created vacuum to aspirate products of conception from the uterine cavity.
History and development of the Manual Vacuum Aspiration
MVA has been around for decades and has been widely used on many continents like Africa, America and Asia, however, it has still not gained a recognisable status in the UK.3 It is thought to have been pioneered by two Chinese doctors (Drs. Wu Yuantai and Wu Xianzhen) in 1958, however their paper was only translated into English on the fiftieth anniversary of the study. It was first introduced to the United Kingdom by Dorothea Kerslake (from the Obstetric department in Newcastle) in 1967. The procedure was refined by a US Psychiatrist Harvey Karnen who developed a flexible and pliable device that avoided the need for cervical dilatation and reduced the risk of cervical trauma or uterine perforation. The NHS was influenced by this work and moved on from rigid plastic cannulas.4
Options for uterine evacuation
There are mainly two types of procedures most widely used for uterine evacuation for early pregnancy: the instrumental curettage and vacuum aspiration. The first one is performed with a rigid metal curette (with either a blunt or sharp end), in the operation room and usually under general anaesthesia. The second uses suction from electrical or manual syringe sources, plastic or metal cannula for evacuating the uterus and can be performed on an outpatient basis (under local anaesthesia or analgesia) or as an inpatient under general anaesthesia.
Advantages of the Manual Vacuum Aspiration over other techniques
Manual vacuum aspiration offers several advantages over other surgical techniques. It is a very simple procedure that due to its safety and efficacy can even be done in an outpatients setting with local anaesthesia, and thus does not require operation theatre facilities. Due to its uncomplicated nature, it can be performed by midlevel providers such as midwives, nurse practitioners and paramedical staff.5
The success of a particular surgical practice depends highly upon patient acceptability, and this procedure has a high level of patient satisfaction whereby it has been noted that between 88 and 95 percent of women say they would recommend MVA to a friend.5 It has been suggested that MVA has advantages over standard surgical curettage for both the patient and the healthcare provider in reducing hospital cost, waiting time and hospital stay.6
Provider training for Manual Vacuum Aspiration
Due to its uncomplicated nature, guidance for performing MVA can be provided at all levels of the heath service. As mentioned above, this service can be provided by both medical and para-medical staff; an exercise that comes in handy in the third-world countries where the relevant patient population may sometimes only come in contact with the para-medical staff.
Patient Selection for Manual Vacuum Aspiration
Manual vacuum aspiration can be carried out on all patients where surgical curettage is indicated, i.e. inevitable and/or incomplete miscarriage, surgical termination of pregnancy, post-partum evacuation for retained products of conception and failed medical management of early pregnancy loss. It can even be used for evacuation of suspected or confirmed molar pregnancy. The pre-operative preparation is similar to what is required for electrical suction evacuation.
Technique of Manual Vacuum Aspiration
Figure 1. a. IPAS MVA Plus Aspirator; b. IPAS Easy Grip cannula; c. Align the liner with the internal ridges; d. Checking the 'O' ring; e. affixing the collar stop; f. charging the aspirator; g. gently introducing the cannula; h. attaching the cannula to the aspirator; i. rotation, suction and gentle in-out motion of the cannula; j. disconnecting the cannula from the aspirator. All images were sourced from the IPAS-USA information booklet on MVA.
The basic requirements for carrying out the procedure are the utilisation of an MVA aspirator and cannula. The most commonly used types worldwide are an Ipas MVA Plus® aspirator and Ipas EasyGrip® cannula.
The following is an excerpt from “Uterine Evacuation with the Ipas MVA Plus® Aspirator and Ipas EasyGrip® Cannulae: Instructional Booklet (Second Edition)”7
The Ipas MVA Plus® aspirator provides between 24-26 inches, or 609.6-660.4 millimetres, of mercury. It is composed of the following parts:
- a valve with a pair of buttons that control the vacuum, a cap and a removable liner;
- a plunger with a plun