Uterine artery pseudoaneurysm: its occurrence after non-traumatic events, and possibility of “without embolization” strategy

Abstract

Objectives

Uterine artery pseudoaneurysm (UAP) has been considered to occur very rarely after traumatic delivery/abortion, and is usually detected after its rupture, yielding massive bleeding. Our hypothesis is: some UAP may be undetected without massive bleeding and may spontaneously resolve, and, thus, may not require transarterial embolization (TAE). We attempted: (1) to detect both ruptured and non-ruptured UAP, thereby characterizing candidates of spontaneously resolving UAP, and (2) to confirm that UAP is not rare and not always associated with traumatic events.

Study design

This was a retrospective observational study of 50 women with angiographically confirmed UAP and treated by TAE. Angiograms and medical charts were retrieved to examine the associations among symptoms, ultrasound findings, and extravasation. Gray-scale ultrasound was performed for all women after delivery or abortion as our routine practice.

Results

UAP occurred in 3–6/1000 deliveries and 40% occurred after non-traumatic deliveries/abortion. While 36% had active vaginal bleeding at admission, 64% did not. While 100% of patients with current active bleeding showed extravasation from the pseudoaneurysmal sac, patients without it showed a varied incidence of extravasation depending on the bleeding pattern/history and ultrasound findings. Interestingly, all patients with current bleeding (−), bleeding history (+), and ultrasound-discernable-intrauterine low echoic mass (−) were devoid of extravasation, suggesting that UAP may show progression to thrombosis and, thus, resolve spontaneously.

Conclusions

UAP may not be so rare and not associated with traumatic delivery/abortion. Some UAP may resolve, and, thus, may not require TAE, at least immediately.

Introduction

During delivery or abortion, the arterial wall is sometimes partly injured, from which hemorrhage occurs. If the surrounding tissues cover this blood accumulation and if the space still has continuity with the parent artery, a pseudoaneurysm forms [1], [2]. A uterine artery pseudoaneurysm (UAP), when it ruptures, sometimes causes massive bleeding [1], [2]. UAP has long been considered to occur “very rarely” after traumatic delivery or abortion, i.e., cesarean section (CS) or dilatation and evacuation (D&E). Previous reports focused on the situation after UAP rupture; vaginal bleeding caused physicians to examine its source, leading to the detection of UAP [1], [2].

We previously reported that UAP shows various features [3], [4], [5], [6], [7], [8], [9], [10], [11]. Widening the study population to patients without bleeding, we preliminarily showed that UAP occurred in approximately 0.2% of deliveries and, thus, is not “very rare”. A half occurred after “non-traumatic” delivery or abortion [12].

The treatment of choice for UAP is transarterial embolization (TAE) [2], [13], [14], [15]. We have been employing a “do TAE immediately after UAP detection” strategy including asymptomatic UAP. This is because it is unknown which UAP will rupture or resolve, and this strategy is consistent with that widely employed at present [2]. However, to “do TAE for all detected UAP” may be overtreatment. The small population in our previous study [12] prevented us from confirming this.

Here, we attempted: (1) to confirm the incidence rate of UAP, (2) to confirm that UAP may no less frequently occur after non-traumatic vaginal delivery/abortion than in traumatic cases, and (3) to characterize UAP that may not require TAE, at least immediately. Importantly, we routinely performed gray-scale ultrasound in all women after delivery or abortion as our routine departmental practice. We analyzed 50 UAP patients, in all of whom angiography confirmed the diagnosis and TAE was performed. Of the 50, 22 had already been reported [12].