A retrospective analysis of the characteristics of acquired uterine arteriovenous malformations associated with retained products of conception.

Objectives: To compare the clinical characteristics and imaging manifestations of retained products of conception (RPOC) with retained products of conception combined with uterine arteriovenous malformation (UAVM-RPOC), to provide a basis for the early identification and clinical treatment of UAVM-RPOC.

Material and methods: A retrospective analysis was conducted on women of reproductive age (89 cases) for retained products of conception. Among the cases, 28 were identified with UAVM-RPOC through ultrasound diagnosis, while 61 were diagnosed with RPOC. The clinical and imaging characteristics of the two groups of women were analyzed, and the treatment methods and prognosis of UAVM-RPOC were also analyzed.

Results: 71.43% women with UAVM-RPOC had a history of two or more previous pregnancies, which was significantly higher than the 45.8% observed in the RPOC group (p < 0.05). The median serum level of β-human chorionic gonadotropin (β-HCG) was 128.7 (16.32-977) mIU/mL. The median time for detecting RPOC in women was 23 days, while the median time to diagnose UAVM-RPOC was 39.5 days. In transvaginal sonography (TVS), 92.86% of women with UAVM-RPOC exhibited low-resistance (RI < 0.5) ultrasound manifestations of the lesion, which was significantly higher than that in the RPOC group (32.79%), p < 0.0001. The contrast-enhanced ultrasound (CEUS) features of UAVM-RPOC were characterized by early-stage lesions showing rapid enhancement, which was followed by a late-stage delay in the washout of the contrast agent compared to the myometrium, leading to sustained enhancement. Out of 28 cases, only one woman underwent hysteroscopic surgery following pre-treatment with uterine artery embolization; the remaining female did not receive pre-treatment, and the surgical success rate for all women was 100%.

Conclusions: Our study revealed the clinical and imaging characteristics of UAVM-RPOC. Transvaginal ultrasound is the preferred examination for diagnosing UAVM-RPOC, but for cases with rich local blood flow signals, further refinement with CEUS examination can be beneficial. The combined examination can better assess the depth of muscle layer infiltration of the lesion, further evaluate the risk level of UAVM-RPOC, and guide clinical treatment.