There is a wide range of embolic agents that are used by interventional radiologists during embolisation procedures, which include temporary agents, such as absorbable haemostatic gelatin, and permanent agents, including PVA particles, coils, plugs, or liquid agents such as N-butyl-2-cyanoacrylate and sodium tetradecyl sulphate injection, and/or a mix of embolic agents [9]. Our study demonstrated that the use of purely absorbable haemostatic gelatin in the UAE is proven to be beneficial and risk-free in treating vaginal bleeding complications associated with acquired UAVM. It appears to offer a high clinical success rate while preserving fertility function, which is a major advantage over the surgical approach. The advantage of the gelatin is based on its temporary haemostatic effect, which gradually dissolves and is absorbed over time [10]. Its biodegradable nature allows for the successful obliteration of the AVM while minimising potential long-term uterine necrosis that could impact future placental implantation or fetal development [11].

The clinical success rate with absorbable haemostatic gelatin embolisation is 83.3% in our study, which is concordant with the published success rates of 88.4–94.1% in the literature that used a wide range of embolic agents [9, 12]. A systematic review by Ruiz Labarta et al. in 2022, which included 371 patients, reported a primary success rate of 79.2% [9]. This systematic review included studies utilising mixed materials (52.3%), including PVA particles, liquid agents, and other unspecified embolic agents; however, no absorbable haemostatic gelatin UAE was included. The available literature on absorbable haemostatic gelatin embolisation alone in the treatment of uterine AVM is relatively scarce. Camacho et al. reported a 94.1% success rate, which included 17 patients between 2013 and 2018, on the efficacy of gelatin UAE for acquired UAVM [12]. Our clinical success rate is close to that published by Camacho.

Our study showed that 3/6 patients (50%) subsequently became pregnant following gelatin UAE, with an average time to pregnancy being 19 to 36 months after embolisation. All 3 patients had successful full-term pregnancies, which suggested the presence of sufficient uterine blood flow to support a full-term pregnancy despite previous gelatin UAE. Other studies revealed an uncomplicated pregnancy rate of 41.2–77% [9, 12]. Ruiz Labarta et al. reported a major complication rate of 1.6%, including pulmonary embolism with embolic agent migration into the systemic circulation [9]. No pulmonary embolism or other complication was observed in our study.

Nevertheless, repeat embolisation utilising additional permanent embolic agents, such as microcoils, may be necessary in patients with larger or more complex vascular lesions [12]. These permanent agents help achieve more permanent occlusions, leading to a significant decrease in vascularity to the UAVM and thereby controlling uterine haemorrhage. In our study, 1 case with a complex vascular lesion developed recurrent bleeding and therefore required repeat embolisation with microcoils and sodium tetradecyl sulphate injection to achieve optimal results. This approach aligns with the findings of Wang et al., which included 11 out of 42 patients with large arteriovenous fistulae that underwent microcoil embolisation [13]. It demonstrated that a more aggressive approach with microcoils is preferred in cases of large arteriovenous fistulae encountered during the procedure, which provides long-term durability that could prevent recurrent haemorrhage [14].

This study also supports the premise that the UAE, with absorbable haemostatic gelatin, necessitates shorter hospital stay compared to hysterectomies. In our study, the mean post-procedural length of hospital stay for patients who underwent absorbable haemostatic gelatin embolisation was 1 to 2 days. In Kim et al., the average hospital stay following hysterectomy was 4 to 8 days for laparoscopic and open abdominal hysterectomy [15]. Hysterectomy poses a higher risk of complications, including postoperative infection in 9–13% of patients, venous thromboembolism in 1–12% of patients, genitourinary injuries in 1–2% of patients, bleeding complications, dehiscence, and neuropathy [16]. These emphasise the advantages of shorter hospitalisation and fewer complications associated with gelatin UAE compared to hysterectomy. Additionally, the shorter length of hospitalisation generally reflects quicker recovery time and minimises the risk of in-hospital complications [17].

Several limitations were observed in this study. Given the rarity of UAVM, this study had a relatively small cohort size. The findings may not be representative of the larger population. Since this was a single-institution case series study, the results might not be representative of other institutional settings, which may have different patient demographics, clinical practices, and healthcare systems. As such, future multi-institutional collaborations or diverse patient recruitment would be beneficial in comparing outcomes and complications of various treatment options. Another limitation of this study is the lack of documentation of any menstrual cycle changes post-UAE, as there may be some degree of blood supply alteration to the uterus that could influence menstrual cycles. Any alterations in menstrual function may go undetected. Future research incorporating menstrual cycle data to provide more comprehensive outcomes and the impact of absorbable haemostatic gelatin embolisation on reproductive health may be considered.