This study highlights the successful implementation of a quality improvement process and protocol using transvaginal ultrasound during dilation and suction curettage to reduce withheld conception products and associated reoperation rates in an academic teaching facility. We also observed a trend towards a decrease in related complications such as bleeding and endometritis; however, this did not achieve statistical significance. It is important that we do not have an increased incidence of compensatory measures to improve quality (defined as a positive change in one part of a system adversely affecting another) or of sequelae such as Asherman’s syndrome or uterine perforation after implementation.
One of the strengths of our study is the standardized definition of withheld conception products to reduce observer bias. Retained POC were defined by both symptoms, which led to a work-up that revealed a sonographic finding that required medical or surgical intervention (heterogeneous and thickened endometrium with Doppler flow) and was confirmed by pathological and / or visual analysis of the retained products . It is important that the finding of a thickened and irregular endometrium with low-resistance Doppler flow after the procedure can be a normal variant in up to 32% of women 1 week after the procedure . Therefore, in each case, a comprehensive clinical evaluation should be performed to determine the likelihood of retention products of conception before an intervention is decided. Finally, a major strength of our study was that our Olmstead County patient population had near universal follow-up care for the postoperative miscarriage assessment at appointments, which made determination of both procedural complications and retreatment much more reliable.
One of the limitations of our study is the possibility of a Hawthorne effect, where surgeons change their procedural performance and attention to detail when they learn that their results are being investigated. We also attribute the increased diagnosis of incomplete abortions after implementation to improved documentation of case details such as preoperative bleeding or cervical dilatation, which is due both to the surgeon’s awareness of the start of the study and to the switch to a new electronic medical record and diagnosis codes at the same time with the phase after implementation. Further limitations are the quality improvement-based methodology, which enables a standardized implementation of the intervention without participation in a prospective cohort or randomized controlled study. Fortunately, this methodology allows the quality improvement process to continue by monitoring retained product or design rates in the future. In addition, our study had a small sample and event size, which prevented statistical adjustment for characteristic differences. Despite these limitations, however, open statistical significance was found. Finally, we also recognize the evidence base for the safety of manual vacuum extraction, which was temporarily not carried out at our facility during this period. In fact, previous authors have similarly low complication rates for MVA compared to EVA. shown [15,16,17], which suggests that conclusions can be drawn about the benefits of transvaginal sonography in this population as well.
While we were able to achieve a significant reduction in retention products of conception, the pre-intervention incidence of retention POC in the current study was slightly higher than reported in the literature, which may have skewed our results toward significance. This may have been representative of several factors, including near-full patient follow-up to detect all cases, as well as the complexity of some patients referred to a tertiary referral center. We are encouraged to compare our results with the previous Debby et al. are congruent, showing a reduced incidence of conception residue when curetting to an endometrial thickness of less than or equal to 8 mm. noted . Importantly, our study differed in two ways: first, in the quality improvement-based design with an emphasis on process-based improvement, and second, that we gave the surgeon autonomy by not prescribing an arbitrary cut-off of the endometrial thickness. Wong et al. found that the diagnosis of retained conception products based on an endometrial thickness greater than 8 mm has a limited specificity of about 80%. . For this reason, we advocated using the surgeon’s clinical experience in interpreting the appearance of a patient’s endometrium on ultrasound so that there are no cases of retained conception products.
Our results suggest that transvaginal sonography can be used as an effective safety check to confirm complete uterine evacuation after dilation and suction curettage procedures. The addition of the procedure does not add surgical risk to the patient, but gives reassurance to both the surgeon and the patient. While we did not bill for our bedside sonography use during this quality improvement study, this could be done at the discretion of the provider. Finally, educating residents in the use of transvaginal sonography is an important skill for future independent practice, and scanning in this supervised environment will add to their experience. While our study focused on procedures in the first trimester, additional studies should be conducted to evaluate the use of transvaginal sonography in dilation and evacuation procedures in the second trimester and in patients with Müllerian abnormalities. Previous studies have suggested that curetting be achieved to a target endometrial thickness to ensure uterine evacuation ; however, we suggest that larger multicenter studies are needed to validate the safety of both this objective cutoff-based and our subjective approaches.