1914. Clinical Outcomes for Enhanced Myometrial Vascularity in Patients with Postpartum Hemorrhage and Suspected Retained Products of Conception
Authors * Denotes Presenting Author
  1. Shrilakshmi Vyas *; University of California, San Francisco
  2. Hailey Choi; University of California, San Francisco
  3. Dorothy Shum; University of California, San Francisco
  4. Sara Whetstone; University of California, San Francisco
  5. Priyanka Jha; University of California, San Francisco
  6. Joseph Rabban; University of California, San Francisco
  7. Liina Poder; University of California, San Francisco
The postpartum uterus can be a diagnostic challenge to radiologists due to its varied imaging appearance, particularly with regards to myometrial vascularity. Enhanced myometrial vascularity (EMV) [1] can be confused for a uterine arteriovenous malformation or fistula (AVM/AVF) on imaging, particularly in the setting of hemorrhage. The objective of this study was to review clinical outcomes in patients with EMV in the setting of suspected retained products of conception (RPOC) and determine the pathologic correlate for EMV.

Materials and Methods:
In this IRB-approved, retrospective study, pelvic ultrasound (US) with keywords of postpartum hemorrhage (PPH) and retained products of conception (RPOC) from 2017-2019 were included. Patients with no follow-up documentation were excluded. US at initial presentation was reviewed for endometrial thickness and endometrial vascularity score. Medical records were reviewed for management approach – expectant, medical management, dilatation and curettage (D&C), or uterine artery embolization (UAE) – post-procedure complications, last clinical follow-up and pathology results. Images were retrospectively reviewed for presence of EMV, endometrial thickness and vascularity [2], and spectral Doppler analysis (where available). Fischer’s exact and Wilcoxson tests were performed.

US query yielded 196 exams, of which 155 subjects were included. 49 (32%) had US findings of EMV. EMV-positive subjects had shorter time interval since delivery (median 23.5 days vs 45 days) (p<0.05). EMV-positive patients demonstrated a median endometrial thickness of 19 mm and endometrial vascularity score of 2, versus 9 mm and score of 0 in EMV negative cases (p<0.05). Of the 49 subjects, 35 (71%) had surgical management, 8 (16%) expectant, 2 (4%) medical, and 4 (8%) underwent UAE (3 for questioned AVM on US); none had an AVM/AVF on angiography. Mean follow up period per patient was 462 days (19-1,069 days). Most underwent uncomplicated D&C. One patient had significant bleeding at D&C and required UAE. Pathology was available for 35 patients, of which 32 (91%) confirmed RPOC. Further review for involuting placental implantation site is pending.

EMV is a relatively commonly encountered and associated finding in suspected RPOC (likely reflecting subinvolution of the placental site), which should not be mistaken for AVM/AVF. There is a low incidence of EMV-associated complications, and most patients can safely undergo watchful waiting or D&C, per symptom severity.