We present a case of a 42-year-old female gravida 2, para 0 (G2P0) who was admitted to our hospital with a suspected uterine arteriovenous malformation indicated by US and MRI.
The patient was implanted with an embryo by assisted reproduction technology on March 1, 2022. At the end of March, presenting mild vaginal bleeding, she did US examinations twice in two days, one showed the gestational sac was located in the right uterine horn, considered a cornual pregnancy, while the latter one indicated that the embryo was only near the right uterine horn but still inside the uterine cavity, so she didn’t do the further examination or treatment. On April 4, 2022, she was diagnosed with embryo demise and had a drug-induced abortion, after which the US examination was performed immediately and showed no residue, thus the curettage wasn’t done. The patient underwent four times failed embryo transfers in the past two years and went through a hysteroscopic surgery due to repeated transplant failure, which found and resected intrauterine adhesion. There was nothing else special in her other past medical histories.
She did the transvaginal sonography because of mild cramping in the right lower abdomen in early July and found a suspected uterine arteriovenous malformation. Doppler US revealed an area that was 2.2cm×1.6cm in the right region of the myometrium with abnormally rich blood flow signals, as well as another mixed echo area, 3.4cm×3.4cm×3.3cm, in the right uterine horn, which showed tortuous dilated veins and a high-velocity low-resistance signal pattern of blood flow with the arterial waveform on spectral analysis, with a peak systolic velocity of 50cm/s (Fig. 1a,1b). The patient underwent contrast-enhanced magnetic resonance imaging (MRI) of the pelvis. Multiple tortuous flow voids cou in an obviously bulging area on the right side of the uterus (Fig. 1c).
After the abortion, she failed to restore a regular period, with only a small amount of vaginal bleeding at the beginning of June, July, and August which may be menstruation. Her β-human chorionic gonadotropin (β-hCG) slowly decreased but was constantly above normal (Fig. 2).
She was suspected diagnosed with uterine AVM when admitted to our hospital on 2022 Aug 9. Because the patient's β-hCG hadn’t dropped to normal, the possibility of complications with residual pregnancy material or gestational trophoblastic disease couldn’t be ruled out. Doppler US was repeated after hospitalization on August 9, which showed abnormal blood flow signals in the right-sided region of the fundus uterine muscle, which was 2.9×2.3cm, PSV = 55cm/s. A mix echo area, 4.4×4.1×3.3cm, was seen on the right uterine corner. Dilates venous vessels could be seen in this area with pulsatile blood flow spectrum, PSV:51cm/s, and RI:0.30.
After professional groups’ discussion and adequate preoperative preparation, laparoscopy and hysteroscopy were performed on August 10. Being fully aware of the operative bleeding risk, we booked 8 units of red blood cells (RBC) and 800ml plasma in our hospital blood bank.. Laparoscopy was performed using 4 ports: 1 placed in the sub umbilical area (10 mm), 2 in the left lower abdomen (5 mm), and 1 in the right lower abdomen (10 mm). Under laparoscopy, the right corner of the uterine was externally bulging with dilated uterine vessels on its root and surface(Figure 3a). Before cutting open, 2 units of pituitrin were dispensed into 40ml normal saline then local injection was made at the lesion site. Bipolar electrocauterization was gently used on the surface of the bulge to minimize bleeding. Bipolar incised the bulge and exposed stale dull red organize. Through sharp and blunt dissection, the abnormal tissue inside the bulge was completely removed and did not pierce the uterine cavity (Fig. 3b). The incision was closed in two layers using a continuous absorbable suture (Fig. 3c). All specimens were sent for pathological examination.
Hysteroscopy was performed under laparoscopy for visual monitoring. A muscular adhesion band could be seen in the lower-middle segment of the uterine. After removed the band, the uterine cavity was exposed (Fig. 4), which was morphologically irregular, indicating a severe intrauterine adhesion. The Bilateral tubal opening was invisible.
The patient recovered well after surgery and was discharged on postoperative day 2. The repeat β-hCG level was 6 IU/L on postoperative day 2 and turned negative on outpatient follow-up one week later after surgery. The regular menstruations returned 1 month postoperatively. However, she felt the bleed length was shortens from 5 days to 3 days, while the amount of bleed was less. The post-operative pathology was stale gestational tissue, which indicated the diagnosis of this patient should be a persistent ectopic pregnancy, right uterine corn pregnancy specifically, however, acquired uterine AVM couldn’t be ruled out.