MVA: an alternate method for uterine evacuation

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:

  1. a valve with a pair of buttons that control the vacuum, a cap and a removable liner;
  2. a plunger with a plunger handle and O-ring;
  3. a 60cc cylinder for holding evacuated uterine contents, with a retaining clip for the collar stop;
  4. a collar stop.

The Ipas EasyGrip® cannulas are available in sizes 4, 5, 6, 7, 8, 9, 10 and 12mm.

  • The smaller cannula (4mm-8mm) have two opposing apertures.
  • The larger cannula (9, 10 and 12mm) have a larger single scoop aperture.
  • Dots imprinted on each cannula indicate the location of the main aperture; the first dot is six centimetre from the cannula tip and dots thereafter are spaced at the one centimetre interval.
  • Cannula are semi-rigid and have permanently attached colour-coded bases; separate adapters are not necessary. Wings on the bases aid in connection to and disconnection from the aspirator.

Assembly and charging of the Ipas MVA Plus® aspirator

In preparation for use, the Ipas MVA Plus® aspirator must first be charged with vacuum, as follows.

  • Open the valve and put the liner in place by aligning the internal ridges. Then close the valve until it snaps into place. Snap the cap into place on the end of the valve.
  • Check the O-ring. Ensure that the O-ring is in the groove at the tip of the plunger. Lubricate it with a single drop of lubricant, such as silicone, glycerol or liquid detergent. Never use petroleum-based products, such as petroleum jelly, on the O-ring as they can deteriorate the rubber. Take care not to over-lubricate the O-ring.
  • Assemble the aspirators by pushing the cylinder into the valve, making sure that the buttons are not engaged while doing so. Push the cylinder straight into the valve. Do not twist the cylinder or valve when assembling, as this will cause the liner to dislodge and may lead to device failure. Insert the plunger all the way into the cylinder. Make sure that the buttons, the wide side of the cylinder base and the plunger handle are in alignment. Then affix the collar stop by sliding it under the retaining clip and pushing its tabs into the holes at the base of the cylinder.
  • Create the vacuum. First, push the buttons down and forward until you feel them snap into place. Then charge the aspirator by pulling back on the plunger until its arms snap outward and catch on the wide sides of the cylinder base. With the arms in this position, the plunger will not move forward and vacuum is maintained. Incorrect positioning of the arms could allow them to slip back into the cylinder, possibly injecting the contents of the aspirator into the uterus. Never grasp the aspirator by the plunger arms.

Check the aspirator for vacuum retention before use. After establishing the vacuum, leave the aspirator for several minutes, and then release the buttons. You should hear a rush of air into the aspirator, indicating there is a vacuum. If you do not hear a rush of air, displace the collar stop, withdraw the plunger and check that the O-ring is properly placed, lubricated and free of damage and foreign bodies. Also check that the cylinder is firmly placed in the valve. Then reinsert the plunger, reposition the collar stop and retest the aspirator. If vacuum is still not retained, the aspirator cannot be used. Discard it and use another aspirator.

Preparing for the procedure

Ensure that all necessary equipment and supplies are available. It is important to select the appropriate Ipas EasyGrip® cannula. Therefore, it is advisable to have cannula of several sizes available. Using a cannula that is too small may result in retained tissue or loss of suction. The size of cannula used depends, to some extent, on provider preference, but also on the estimated size of the pregnant uterus. Inspect your instruments carefully. Ensure that the aspirator holds a vacuum. Discard aspirators with visible cracks or defects and those that do not hold a vacuum. Before beginning, charge the aspirator. If vacuum is not retained, check the O-ring and lubricate if necessary. If vacuum is still not retained, discard and use another aspirator.
The essential equipment required during the procedure includes the following:

  • MVA aspirator
  • Silicone lubrication
  • Cannula (4–12 mm)
  • Adaptor for cannula
  • Speculum
  • Tenaculum (sharp-toothed or atraumatic)
  • Ring forceps
  • Antiseptic solution, gauze, and small bowl
  • Mechanical cervical dilators
  • Syringe, needle, and anaesthetic agent for cervical block (if local analgesia used)

Performing the procedure

The MVA procedure can be started once all instruments and supplies are ready and the woman is prepared and has given her consent to start.

  • Confirm findings of initial examination through bimanual exam, watching for any signs of infection and treating promptly according to protocols.
  • Implement pain-management plan.
  • Perform cervical antiseptic prep.
  • Perform paracervical block, if necessary.
  • Place tenaculum and apply gentle traction if not already done with paracervical block.
  • Dilate cervix, if necessary.
      • Cervical dilatation is necessary when the cervical canal will not allow passage of a cannula appropriate to the uterine size.
    • When required, dilatation should be done gently with progressively larger cannula or tapered mechanical dilators, taking care not to traumatise the cervix.
    • Misoprostol can also be used to ripen the cervix.
  • Suction uterine contents
      • Gently introduce cannula just past the internal os. Alternatively, slowly push the cannula into the uterine cavity until it touches the fundus, then withdraw it slightly. Rotate the cannula with gentle pressure to help ease insertion.
      • Do not insert the cannula forcefully, as forceful movements may cause uterine perforation or damage to the cervix, pelvic organs or blood vessels.
      • Remain alert to signals that may indicate perforation throughout the procedure and stop suction immediately if they appear.
      • Attach cannula to aspirator, holding the tenaculum and end of the cannula in one hand and the aspirator in the other. Take care not to push the cannula further into the uterus.
    • Release vacuum by pressing the buttons in; suction will begin immediately.
      • Evacuate by slowly and gently rotating cannula and aspirator 180 degrees in each direction while using an in-and-out motion. Take care not to withdraw the aperture of the cannula beyond the cervical os, as this will cause a loss of vacuum.
      • Blood and tissue will be visible through the cannula and in the aspirator cylinder.
      • If aspirator becomes full or vacuum is lost, disconnect it from the cannula and either replace it with another aspirator or empty its contents into a receptacle and reattach it to the cannula. Never push aspirated contents through the cannula into the uterus.
      • If cannula removal is necessary during the procedure: Stabilise the cannula by grasping it at the base with one hand and holding it steady; with the other hand, hold the aspirator by the valve body, rotate the aspirator and gently separate it from the cannula. To insert the cannula, hold the aspirator by the valve body (not the cylinder), push the cannula base in firmly, twisting slightly if necessary.
    • Check for signs of completion:
      • Red or pink foam without tissue passes through the cannula;
        • Gritty sensation as the cannula passes over the surface of the evacuated uterus;
      • The uterus contracts around the cannula;
        • The woman feels increased cramping when the uterus is empty, indicating contraction.
      • When the procedure is finished, depress the buttons and disconnect the cannula from the aspirator. Alternatively, withdraw the cannula and aspirator together without depressing the buttons.
  • Inspect aspirated tissue for quantity and presence or absence of products of conception. Empty the contents of the aspirator into an appropriate container by ensuring the cannula is detached, releasing the buttons, squeezing the plunger arms and pushing the plunger fully into the cylinder. Keep instruments available in case re-aspiration is necessary. Inspecting aspirated tissue is extremely important since it indicates whether the evacuation was complete or whether there is the possibility of an ectopic or molar pregnancy.

If no POC are seen, the possibility of ectopic pregnancy, incomplete miscarriage or a complete spontaneous miscarriage should be considered.

  • If retained tissue is suspected, repeat the aspiration.
  • After determining that the procedure is complete, wipe away excess blood from the os and assess the quantity still coming from the uterus or elsewhere.
  • Ensure that bleeding is minimal.
    • Proceed with any concurrent procedures such as IUD insertion or tubal ligation, provided that prior informed consent was obtained and counselling was given.

Complications of Manual Vacuum Aspiration

Numerous studies have documented the safety and efficiency of MVA over the past few decades. Vacuum aspiration is one of the safest surgical procedures available, and the safest way to perform first-trimester evacuation of products of conception.8 The nature of complications after manual aspiration is the same as would be expected after electrical suction curettage and these include haemorrhage, uterine perforation, incomplete evacuation leading to repeat aspiration, cervical laceration, etc. The rate of incomplete evacuation after a dilatation and curettage is reported approximately two to three percent and this is approximately the same for MVA.3
About 98 percent of vacuum aspiration procedures occur without major complications. Vacuum aspiration (electrical or manual) results in significantly fewer complications than sharp curettage, including incidences of excessive blood loss, pelvic infection, cervical injury and uterine perforation.5
Specific data on the safety of MVA find few complications associated with the method. In general, MVA demonstrates a similar level of safety as electrical vacuum aspiration, and greater safety than sharp curettage. A recent Vietnamese study examined 210 first-trimester MVA abortions and included extensive follow up. Patients completed a daily symptom diary for seven days after the MVA, and were interviewed by a healthcare provider weekly for five weeks. No serious complications such as infection or heavy bleeding occurred among the study group.5

Immediate Complications With Manual Versus Electric Suction Aspiration9

Cost Considerations in an Manual Vacuum Aspiration Service

Manual vacuum aspiration is a comparatively inexpensive service to provide, and is much less costly than electronic vacuum aspiration in terms of initial and overall costs. Even when limited to single-use, MVA instruments are considered inexpensive in many facilities. Additional savings are realised when early pregnancy management services are moved out of the operating theatre or emergency room, reducing expenditures for anaesthesia, hospital infrastructure, sterile supplies and patient recovery care.5

A study in Sweden has estimated that performing MVA in the out-patient setting (rather in an operating room) would result in cost savings of 24 percent from the operating theatre and surveillance time. The authors estimated that, if one-tenth of Sweden’s procedures were conducted with MVA, the national savings would be about U.S. $1,140,000 annually.10,5
In addition to the above cost-effectiveness, there is the extrapolated cost-saving from reduced clinical expenses in management of post-MVA complications (i.e. uterine perforation, haemorrhage, repeat aspiration, etc.). With the complication rate of MVA already being less than electrical aspiration, there would be significant cost-cutting from lesser cases requiring medical expenses for management of these complications.5

Manual Vacuum Aspiration as part of an Early Pregnancy Assessment Unit service

A woman undergoing early pregnancy loss is already highly distressed and the usual surgical option is an evacuation of retained products of conception under a general anaesthesia in an operating theatre using electrical vacuum aspiration or sharp curettage. The main difficulty here is that the patient needs to have fasted overnight before the general anaesthetic and so may have to wait until the next day for the procedure. There is also the difficulty of finding an available theatre slot and a free anaesthetist. Furthermore, after the procedure she is likely to feel ‘groggy’ for a day or so and will need to be driven home by someone.11 In patients where silent/inevitable/incomplete miscarriage is confirmed can be surgically managed as a day-case in the outpatient setting by offering MVA. Due to its safety and efficacy resulting from reduced anaesthetic requirement, manual vacuum aspiration has a major role to play in the provision of Early Pregnancy Assessment Services.

The future of Manual Vacuum Aspiration in the UK

Manual vacuum aspiration has not yet gained significant overall acceptance in the United Kingdom for various reasons. Most important in this would be the fact that there is unfamiliarity of the medical and para-medical staff with this procedure leading to a lack of confidence in counselling the patient and performing the actual surgical. Also, as there is usually consistent access to operating room facilities and general anaesthetic in the NHS hospitals, there is a tendency to lean towards the usual standard electrical vacuum aspiration or curettage.3
Nevertheless, decades of safe experience and evidence-based advantages of MVA in other parts of the world cannot be wrong, not the least being a level of cost-effectiveness (without compromising patient safety) in the current economic climate. There is a measured advancement of MVA service provision in the NHS, with some units offering this service in their Early Pregnancy Unit; however, these services need an overhauling and generalised awareness not just for the medical/paramedical staff, but also for the appropriate patient population.

References

  1. Bradley E, Hamilton-Fairley D. Managing miscarriage in early pregnancy assessment units. Hosp Med 1998;59:451–6.
  2. Hemminki E. Treatment of miscarriage: current practice and rationale. Obstet Gynecol 1998;91:247–53.
  3. Milingos D, Mathur M, Smith N, Ashok P. Manual vacuum aspiration: a safe alternative for the surgical management of early pregnancy loss. BJOG 2009; 116:1268–1271.
  4. Coombes R (14 June 2008). “Obstetricians seek recognition for Chinese pioneers of safe abortion”. BMJ (BMJ) 336 (7657): 1332–3.
  5. Baird, Traci L. and Susan K. Flinn. 2001. Manual vacuum aspiration: Expanding women’s access to safe abortion services. Chapel Hill, NC, Ipas.
  6. Blumenthal PD, Remsburg RE. A time and cost analysis of the management of incomplete abortion with manual vacuum aspiration. Int J Gynecol Obstet 1994; 45:261–7.
  7. Frankel, Nina. 2004. Performing uterine evacuation with the Ipas MVA Plus® aspirator and Ipas EasyGrip® cannulae: Instructional CD-ROM. Chapel Hill, NC, Ipas.
  8. Stewart, FH and Weitz TA. Manual Vacuum Aspiration (MVA): A Quick Reference Guide for Clinicians. Association of Reproductive Health Professionals (ARHP). 2004. Washington DC.
  9. Goldberg AB, Dean G, Kang M-S, Youssof S, Darney PD. Manual versus electric vacuum aspiration for early first-trimester abortion: a controlled study of complication rates. Obstet Gynecol 2004;103:101–7.
  10. Hemlin, Johan and Bo Möller. 2001. Manual vacuum aspiration, a safe and effective alternative in early pregnancy termination. Acta Obstetricia et Gynecologica Scandinavica, 80(6):563-7.
  11. Morgan, Leslie. The Case for Manual Vacuum Aspiration. Middle East Health (Durbin). January 2012. p. 136.
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