Abnormal uterine bleeding due to uterine arteriovenous malformation in an early adolescent with intrauterine contraceptive device in situ

Abstract

We report a case of uterine arteriovenous malformation in an early adolescent who presented with heavy vaginal bleeding 2 months after termination of pregnancy with copper intrauterine contraceptive device (IUCD) insertion. The patient was admitted and had medical treatment, including blood transfusion and subsequently transcatheter embolisation of the arteriovenous malformation to control her bleeding. The IUCD was left in situ. Her symptoms completely resolved by 4 months post-procedure.

Background

Uterine arteriovenous malformation (AVM) is a rare but potentially dangerous vascular pathology with multiple abnormal fistulous communications between the branches of the uterine artery and the venous plexus within the myometrium without an intervening capillary network. The incidence reported in the literature ranges between 0.6% and 4.5%.^{1 2} Uterine AVM is usually acquired following pregnancies or uterine instrumentation. Therefore, it should be considered as a differential diagnosis for abnormal uterine bleeding after these events. It typically presents with episodic very heavy vaginal bleeding leading to clinically significant anaemia or even shock requiring emergent stabilisation and treatment.³ Treatment choices should take into account the severity of the symptoms, location and size of the lesion as well as desire for future fertility.

Case presentation

A female early adolescent patient presented to our Urgent Obstetrics and Gynaecology Centre with very heavy vaginal bleeding. She had been having light bleeding for 3 days prior but suddenly experienced a large gush of blood soaking her pad and pants and dripping down her legs. She did not experience any abdominal pain but reported dizziness and lightheadedness associated with shortness of breath.

She reported a previous similar episode 10 days prior that had resolved after taking oral norethisterone 10 mg two times per day.

Her last menstrual period was 18 days before her presentation. Her menstrual cycle was previously regular and normal: bleeding for 5–6 days every 28 days. Before being under our care, she had a normal Pap smear 2 years ago.

She had a history of two surgical terminations of pregnancy 7 months and 2 months before her presentation. A copper intrauterine contraceptive device (IUCD) was inserted during her second procedure. Her medical history included bipolar disorder and dysthymia on lamotrigine, obstructive uropathy with moderate right hydronephrosis, previous excision of right ureterocele, childhood asthma and orbital inflammatory syndrome.

Investigations

At presentation to our urgent centre, her blood pressure was 113/76 mm Hg with a regular pulse rate of 93 beats/min. Her body temperature was 37.2°C. The abdominal examination was unremarkable; no masses or tenderness was noted. The speculum examination showed a normal cervix, the IUCD threads were visible and moderate bleeding was seen from the cervical os.

Her urine pregnancy test was negative.

Serum haemoglobin was 103 g/L on admission but subsequently dropped to 78 g/L.

The ultrasound of her pelvis demonstrated a thin endometrium measuring 3.0 mm. A heterogeneous area measuring 2.5×2.3×2.0 cm with tubular cystic spaces within the anterior myometrium of the uterus showed increased vascularity, multidirectional flow on colour Doppler and a peak systolic velocity of approximately 50 cm/s on spectral Doppler with possible extension into the adjacent endometrium close to the IUCD compatible with uterine AVM (figures 1–3). This finding was not present in a previous pelvic ultrasound from 2 years before (figure 4).

Figure 1.

Anteverted uterus showing anechoic/hypoechoic spaces in the myometrium on greyscale ultrasound, intrauterine contraceptive device in situ (arrow).

Figure 2.

Increased blood flow and turbulent flow on colour Doppler ultrasound of the uterus.

Figure 3.

Spectral Doppler ultrasound showing high peak velocity in the uterine vascular lesion.

Figure 4.

Normal uterus 2 years before presentation.

Differential diagnosis

In a young patient with a recent pregnancy and uterine instrumentation, retained products of conception (RPOC) are the most common differential diagnosis. The typical presentation of patients with RPOC tends to be persistent bleeding starting from the procedure date. On ultrasound, the vascular RPOC are typically confined to the endometrial cavity rather than centred deep within the myometrial layer.

Gestational trophoblastic disease is another important diagnosis that should not be missed. Ultrasound in these cases usually shows multiple echogenic microcystic structures within the endometrial cavity. This was not considered for the above patient as the histopathology of the products of conception sent at the time of her termination of pregnancy (TOP) confirmed normal pregnancy tissue.

Post-procedure endometritis especially with an IUCD in situ may also present with continued or renewed vaginal bleeding. The presence of fever and positive vaginal swab cultures together with an elevated white cell count would favour this diagnosis.

Uterine AVM can be either congenital or acquired, the former being extremely rare. Comparison with previous ultrasound findings might be helpful to determine this difference. However, ultrasound is operator dependent, and small foci might go undetected.

Treatment

The patient was admitted to our gynaecology ward for monitoring of her vaginal bleeding. She was started on norethisterone 10 mg two times per day orally as well as iron supplementation. During her admission, she had multiple episodes of intermittent torrential vaginal bleeding leading to clinically significant anaemia requiring blood transfusion. Removal of the IUCD was recommended but declined by the patient as this was the only acceptable form of contraception to her and she had two recent unwanted pregnancies.

The patient and her parents were counselled on the various options of medical management as well as transcatheter arterial embolisation. They opted for embolisation given the poor response to the medical treatment manifested as continued heavy bleeding.

A pelvic angiogram demonstrated the uterine pseudoaneurysm with AVM, predominantly supplied via the right uterine artery. Successful superselective uterine AVM embolisation was performed using 355–500 nm polyvinyl alcohol particles (figures 5 and 6). Immediate post-procedure ultrasound confirmed reduced size and avascularity of the uterine AVM.

Figure 5.

Digital subtraction angiography before embolisation shows leash of vessels in the myometrium/endometrium closely adjacent to the in situ intrauterine contraceptive device.

Figure 6.

Digital subtraction angiography after embolisation, intrauterine contraceptive device in situ, shows patency of the main right uterine artery but pruning of the leash of vessels in the myometrium/endometrium.

The IUCD was left in situ in keeping with the patient’s wishes.

Outcome and follow-up

The patient experienced post-embolisation pain that was treated by patient-controlled analgesia. Her bleeding reduced significantly, and she was discharged on post-procedure day 2. At her clinic follow-up 2 weeks later, her vaginal bleeding was only minimal, and her ultrasound scan showed no flow in the expected region of the AVM.

On review 4 months after embolisation, the patient reported that her menses had returned to normal with the IUCD remaining in situ.

Discussion

Uterine AVM is a rare condition and there is no clear consensus about the best treatment option. Historically, hysterectomy was the definitive treatment, but more recently, medical treatment as well as endovascular therapy by angioembolisation have been advocated for women wishing to preserve fertility potential.

Ultrasound is useful in the initial evaluation and exclusion of differential diagnoses. Typically, anechoic or hypoechoic foci are seen within the myometrium on greyscale ultrasound, increased uterine vascularity and turbulent flow on colour Doppler and high peak velocity on spectral Doppler.² Catheter angiography remains the gold standard for a definitive diagnosis but is an invasive procedure and is usually only performed when transcatheter embolisation is considered.³

Medical treatments that have been proposed include methylergonovine maleate, danazol, combined contraceptive pill, gonadotrophin-releasing hormone agonists, injected medroxyprogesterone acetate, oral norethisterone and tranexamic acid.³ These treatments are varied and based on anecdotal case reports and case series, but no uniform treatment regime exists. Furthermore, spontaneous resolution has also been reported in some cases congruent with our institution’s experience.⁴ As such, the mechanism of action of these medical therapies remains to be fully understood.

Surgical management traditionally included hysterectomy or internal iliac artery or uterine artery ligation.⁵ Newer techniques including laparoscopic bipolar coagulation of uterine vessels and more recently hysteroscopic excision of the AVM have shown promising results.^{6 7}

Transcatheter embolisation of uterine AVM has become an established treatment for women with uterine AVM who have failed to respond to medical treatment or require transfusion to maintain haemodynamic stability and wish to preserve their fertility.⁸ Successful pregnancies have been reported after this procedure and attributed to adequate collateral uterine blood flow.² A retrospective audit of 27 women undergoing transcatheter embolisation of uterine AVM has revealed 34 pregnancies and 31 live births post-procedure.⁹ This is especially important when treating nulliparous or early adolescent patients as in our case.

Our case was further complicated by the in situ IUCD that was inserted for contraception post-TOP as the patient declined all other forms of contraception due to side effects of previously tried hormonal contraception as well as her medical comorbidities. There were concerns as to whether the abnormal uterine bleeding was due to the IUCD, and removal was discussed with the patient. After diagnosing the uterine AVM on ultrasound imaging, it was discussed whether mechanical irritation of the vascular lesion due to the proximity of the foreign body might increase the blood loss or whether removal of the IUCD might potentially precipitate torrential bleeding.

No other similar case was found in the literature to guide management. One case reported by Selby and Haughey describes the use of a hormonal intrauterine device as a form of medical treatment for AVM after the bleeding subsided.¹⁰ As the patient declined the removal of the IUCD, we proceeded with the embolisation leaving it in situ. The return of normal menses in our patient after transcatheter embolisation despite having an IUCD in situ suggests that it can be reasonable to consider retaining the device when other pathologies can be treated.

Learning points.

• Arteriovenous malformation (AVM) should be included in the list of differential diagnoses in patients with acute and heavy vaginal bleeding, especially on the background of a recent pregnancy or uterine instrumentation.

• Colour Doppler and spectral Doppler ultrasound of the pelvis may be helpful in differentiating between retained products of conception and uterine AVM.

• Uterine artery embolisation is an appropriate minimally invasive treatment in early adolescents/young adults with uterine AVM who fail to respond to medical therapy.

Ethics statements

Patient consent for publication

Obtained.