P-409 Intrauterine adhesion in Ultrasound-guided manual vacuum aspiration (USG-MVA) versus electric vacuum aspiration (EVA): a randomized controlled trial
Authors: Chung J  P W , Law T  S M , Ng K , Ip P  N P , Li T  C 
Published: July 2024

Abstract

Study question
Does ultrasound-guided manual vacuum aspiration (USG-MVA) have a lower incidence of intrauterine adhesion (IUA) compared to conventional surgical evacuation?

Summary answer
The rate of intrauterine adhesion following ultrasound-guided manual vacuum aspiration (USG-MVA) was significantly lower compared to conventional surgical evacuation (EVA).

What is known already
Miscarriages are common in pregnant women and can be managed through conservative, medical, or surgical approaches. Traditional surgical evacuation for early pregnancy loss involves electric vacuum aspiration (EVA) under general anesthesia. However, manual vacuum aspiration (MVA) offers a cost-effective, portable, and easy-to-administer alternative. MVA has shown high effectiveness and minimal complications. By incorporating ultrasound guidance (USG), MVA can further reduce discomfort and minimize the risk of future intrauterine adhesions (IUA) due to its protective effect on the endometrium. However, the incidence of IUA after USG-MVA is still not known.

Study design, size, duration
This was a prospective single-centre, randomised controlled trial conducted in a university-affiliated tertiary hospital from May 2019 to September 2022. Patients were randomized into USG-MVA group or the EVA group. They were invited to come back for a hysteroscopic assessment for IUA at 6-20 weeks post-surgery to assess the incidence of IUA. Patients were contacted by phone at 6 months to assess their menstrual and reproductive outcomes.

Participants/materials, setting, methods
Chinese women aged ≥18 with a delayed miscarriage of up to 12 weeks of gestation or an incomplete miscarriage were randomly assigned to receive either USG-MVA or EVA for their miscarriage management. An outpatient hysteroscopy was conducted by a team of experienced gynecologists who had comparable surgical expertise within a timeframe of 6 to 20 weeks from USG-MVA or EVA. These gynecologists were unaware of the women’s initial surgical procedure performed for the first-trimester miscarriage.

Main results and the role of chance
This study included 303 patients who underwent surgical evacuation, with 152 receiving USG-MVA and 151 receiving EVA. Hysteroscopic assessments were completed by 126 patients in the USG-MVA group and 125 patients in the EVA group.
The incidence of IUA was statistically (p &lt; 0.02) lower in the USG-MVA group (19.0% ) when compared to the EVA group (32.0%). Interestingly, although there was no significant difference in menstrual outcomes at 6 months postoperatively between the two groups, a higher number of patients in the EVA group with IUA experienced subsequent miscarriages.
Hysteroscopic adhesiolysis was performed during hysteroscopy when it is diagnosed to restore uterine cavity. XX USG-MVA patients underwent hysteroscopic adhesiolysis, compared to 36 patients in the EVA group. Two patients in the EVA group required additional treatment in the operating theatre or as an outpatient, and one patient did not follow-up as scheduled.
The EVA group had a higher proportion of patients with hypomenorrhea among those who had previous intrauterine surgeries compared to the USG-MVA group, although this difference was not statistically significant.
Overall, USG-MVA appears to be a more effective and safer option for managing early pregnancy loss due to its lower incidence of IUA and potential reduction in subsequent miscarriages.

Limitations, reasons for caution
Performing USG-MVA, as opposed to a blind MVA procedure, however, requires additional equipment and staff with appropriate training. There is no direct comparison between MVA and EVA with USG. The study only followed patients up to 6 months post-operation, which cannot further assess their fertility outcomes.

Wider implications of the findings
USG-MVA offers cost savings and increased patient comfort by being performed in an outpatient setting. Shifting procedures from the operating room to ambulatory settings reduces expenses and allows patients to avoid general anesthesia, promoting autonomy and quicker recovery.

Trial registration number
ChiCTR1900023198