Challenges in the Management of Postmenopausal Uterine Artery Venous Malformation

ABSTRACT

Uterine arteriovenous malformation (UAVM) is an infrequent occurrence among postmenopausal women. Our review of the literature revealed only a few documented cases of UAVM in this demographic. Treatment options for these patients encompass uterine artery embolization (UAE), medical management, and hysterectomy. We encountered a case involving a 54-year-old woman, postmenopausal for 9 years, who presented with a history of postmenopausal bleeding over the preceding 3 months. Imaging studies confirmed the presence of UAVM. Despite an attempted UAE, the procedure proved unsuccessful, leading to the decision to perform a hysterectomy with meticulous attention to minimizing blood loss. Notably, UAE may not consistently achieve favorable outcomes in addressing UAVM in postmenopausal women, thereby underscoring the consideration of hysterectomy as a safe alternative – treatment option without any excessive intraoperative bleeding.

INTRODUCTION

Uterine arteriovenous malformations (UAVMs) denote anomalous connections between intramural arteries and myometrial venous plexus, lacking an intervening capillary network.[1] Typically manifesting as intermittent and potentially life-threatening vaginal bleeding, UAVMs are commonly encountered in reproductive age, often in association with pregnancy complications, but also manifest in postmenopausal women.[2,3] Owing to its rarity, its prevalence, particularly in the postmenopausal demographic, remains indeterminate.

UAVMs are categorized as congenital or acquired. Although rare, congenital UAVMs are observed in reproductive age due to abnormal vascular connections arising during embryonic differentiation and angiogenesis.[1] Conversely, acquired UAVMs result from uterine trauma caused by procedures such as cesarean section, myomectomy, dilatation and curettage, gestational trophoblastic disease, endometrial malignancies, infections, or fibroids.[1]

The etiology of UAVMs in postmenopausal women lacking identifiable risk factors remains uncertain, and definitive guidelines for managing UAVMs in this demographic are currently lacking. We present a case study of a postmenopausal woman with UAVM who presented with abnormal vaginal bleeding, offering insights into the diagnosis and management of this condition.

CASE REPORT

A 54-year-old parous woman with three vaginal deliveries, postmenopausal for 9 years, presented with recurrent painless vaginal bleeding over 3 months. She had no history of abortions or surgical interventions. Upon initial assessment, she exhibited stable vitals with minimal vaginal bleeding. Physical examination indicated a normal-sized uterus and adnexa with distinctly increased pulsations felt through the fornices. Color Doppler ultrasound showed increased vascularity inside the uterus [Figure 1]. Magnetic resonance imaging (MRI) indicated the presence of multiple serpentine vascular flows in the uterine wall, endometrial cavity, and parametrium, suggesting an arteriovenous malformation (AVM).

Figure 1.

Ultrasound showing increased vascularity in a normal uterus

The treatment options for AVMs included medical management, uterine artery embolization (UAE), and hysterectomy. Due to the limited understanding of postmenopausal AVMs, the absence of consensus on management, and the associated risk of intraoperative bleeding, the decision was made to proceed with bilateral UAE. Preprocedural computed tomography (CT) angiography revealed a hyper-enhancing nidus with dilated and tortuous feeders arising from the bilateral uterine arteries, supply from the right ovarian artery, and early drainage into a vein [Figure 2].

Figure 2.

(a) Axial contrast-enhanced computed tomography, (b) sagittal section (c) VR image – Hyper-enhancing nidus with dilated and tortuous feeders from bilateral uterine arteries (right > left) with early draining vein - s/o arteriovenous malformation

During the procedure, adhesive material entered systemic circulation due to the high flow in the right uterine artery (UA). A 12 mm balloon was deployed in the right internal iliac artery through a contralateral approach while maintaining the microcatheter within the right UA. Balloon occlusion effectively reduced the flow, facilitating embolization with a 70% adhesive mixture. Subsequently, the left UA was embolized using a 35%–40% adhesive lipoidal mixture [Figure 3]. However, the embolization of the right ovarian vessels was precluded by cannulation challenges arising from vessel thinning and kinking.

Figure 3.

(a) Arteriogram pre-embolization showing a tangle (yellow arrow) of vascular structures fed by bilateral uterine arteries. (b) Balloon (white arrow) occlusion of right uterine artery during embolization. (c) Postprocedure arteriogram showing absence of filling of occluded uterine arteries

Following the embolization procedure, the patient developed a prolonged 20-day fever, subsequently resolved with antibiotics. A subsequent CT angiogram, performed 1-month post-embolization, revealed a partial obstruction in both UA, with abnormal blood flow originating from the right uterine and ovarian arteries. The patient underwent abdominal hysterectomy and removal of the adnexa, with a blood loss of 300 ml. Intraoperatively, abnormal enlargement and tortuosity of the right ovarian and uterine arteries were noted. The uterus measured 7.5 cm × 6.5 cm × 2 cm with a normal endometrial cavity with multiple dilated blood vessel lumen opening into the endometrium [Figure 4]. Microscopic examination was normal. The patient had a smooth postoperative recovery and has been asymptomatic for 1 year.

Figure 4.

Cut section of uterus showing lumen of blood vessels opening into the endometrial cavity

DISCUSSION

UAVMs are infrequent in postmenopausal women. After an extensive literature review, it was established that only six cases of UAVMs have been documented within this specific demographic. Reported AVMs are found in the reproductive age group, with a significant proportion having undergone prior surgical interventions. Our patient was postmenopausal and had not undergone any surgeries nor had any high-risk factors for the development of AVM.

Zhang et al. postulated that smaller veins converging into uterine vein may become obstructed due to infection, malignancy, or surgical intervention. In such cases, blood can be directed into the uterine vein through an interconnected network of dilated capillaries. Heightened blood flow and intravascular pressure may lead to increased capillary diameters and the formation of AVMs.[1]

Patients exhibit symptoms such as heavy menstrual bleeding, recurrent abortions, abdominal pain, and dyspareunia. Rarely, it may manifest as pulsatile pelvic mass and lead to cardiac decompensation.[4] Our patient had a history of postmenopausal bleeding and was hemodynamically stable, as reported by Zhang et al.[1]

Recommendations advise that women experiencing postmenopausal bleeding undergo primary evaluation using either endometrial biopsy or transvaginal ultrasound.[5] Surgical intervention in AVMs can cause substantial bleeding and hence should be excluded, mainly if heightened pulsations are detected during a pelvic examination.[6]

Color Doppler ultrasound and spectral analysis are the initial diagnostic tools, and they can be validated using CT and MRI.[7] Pelvic angiography is the gold standard, enabling the identification of feeder vessels for embolization.

There is currently no consensus on the optimal management of UAVMs.[1,8] Two reported cases of postmenopausal AVMs resulted in unsuccessful outcomes following UAE, necessitating subsequent hysterectomies. Similarly, UAE in our patient yielded unsatisfactory results. UAE has been successful in women of reproductive age. In both cases mentioned above and in our patient, the ovarian and uterine vessels exhibited abnormal dilation and high-velocity flow, resulting in challenges during embolization. Tortuosity and kinking of vessels in postmenopausal women further compound the procedural complexity. Inadvertent embolization resulting in nontargeted vascular occlusion can precipitate end-organ ischemia and bacterial sepsis.[9] In this case, the patient presented with high-grade fever, which exhibited improvement with antibiotics, potentially indicative of a complication of UAE.

Postmenopausal AVMs have been associated with heavy bleeding or mimic malignancies, leading to hysterectomy.[4,10] Surgical intervention in these cases resulted in minor intraoperative bleeding, suggesting that hysterectomy does not cause significant hemorrhage. Notably, UAE is expensive and carries a substantial risk of failure, whereas hysterectomy has demonstrated higher efficacy with minimal blood loss. Consequently, it is prudent to consider hysterectomy as the primary treatment modality for postmenopausal UAVMs, reserving UAE as the preferred option for women of reproductive age.[1]

CONCLUSION

UAVMs are infrequent in postmenopausal women. UAE may not represent the primary treatment modality in this age cohort; however, it could be a preferable option in the reproductive age group. Hysterectomy is a viable treatment alternative characterized by minimal intraoperative bleeding.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.