Abstract
Background and Clinical Significance: Uterine artery embolization (UAE) is a well-established treatment for symptomatic leiomyomas; however, treatment failure may occur owing to collateral arterial supply from extra-uterine sources. While ovarian artery collaterals are the most commonly reported cause, parasitic vascularization from the celiac axis and superior mesenteric artery (SMA) remains exceedingly rare and poorly documented; Case Presentation: A 41-year-old woman with symptomatic fibroids underwent technically successful bilateral UAE. Follow-up imaging revealed persistent vascularity of a dominant 19 cm pedunculated fibroid supplied by collateral branches from the celiac axis and SMA. As surgery was contraindicated owing to a recent pulmonary embolism that occurred after UAE, gonadotropin-releasing hormone (GnRH) agonist therapy was initiated, resulting in partial fibroid shrinkage and symptomatic improvement; Conclusions: Persistent fibroid vascularization after technically successful UAE may result from unrecognized extra-uterine arterial feeders. Cross-sectional angiographic imaging is essential for identifying atypical collateral pathways and guiding subsequent management in cases of treatment failure.
Keywords: uterine artery embolization, uterine fibroid, collateral circulation, superior mesenteric artery, celiac axis, parasitic arterial supply
1. Introduction and Clinical Significance
Uterine artery embolization (UAE) is a well-established, minimally invasive, uterus-preserving treatment for symptomatic leiomyomas, with clinical success rates exceeding 80% and sustained long-term outcomes [1,2].
Collateral arterial supply, most commonly from the ovarian arteries, is a recognized contributor to UAE failure [3]. More rarely, parasitic vascularization may originate from branches of the inferior mesenteric artery (IMA) or the superior mesenteric artery (SMA), sustaining fibroid perfusion despite technically adequate embolization of the uterine arteries [3,4,5]. Chang et al. reported that IMA collaterals were present in 1.3% of UAE cases and were associated with larger uterine volumes and adenomyosis [4]. Dixon et al. described successful embolization of IMA collaterals following prior UAE failure [5], while Song et al. documented aberrant fibroid supply from SMA branches requiring selective embolization [3]. Cross-sectional vascular imaging, particularly contrast-enhanced MR angiography and CT angiography, plays a key role in detecting these atypical feeders and guiding re-intervention [6].
This case describes UAE failure due to parasitic arterial supply from both the SMA and celiac axis—a combination that, to our knowledge, has not been previously reported. We highlight the diagnostic and therapeutic challenges posed by extra-uterine collateral pathways and review the relevant literature.
Clinical Significance: This report documents a previously underreported pattern of incomplete embolization due to dual parasitic arterial supply to a uterine fibroid from the celiac axis and SMA following technically successful UAE. Recognition of such atypical collateral pathways is critical for avoiding treatment failure and guiding management in patients with large or pedunculated fibroids.
2. Case Presentation
A 41-year-old premenopausal woman with a history of hypertension, morbid obesity and endometriosis presented with menorrhagia and pelvic pressure refractory to medical therapy. Magnetic resonance imaging (MRI) revealed a dominant 18.9 cm FIGO type 7 pedunculated fibroid arising from the uterine fundus, along with multiple smaller intramural fibroids (Figure 1). Pre-procedural contrast-enhanced MR angiography demonstrated hypertrophied bilateral uterine arteries with no detectable ovarian or other extra-uterine arterial supply to the fibroids (Figure 1). Given the patient’s preference, and that it has been shown that UAE is safe and effective even for giant fibroids [7], UAE was chosen over surgical treatment. Table 1 lists the advantages and disadvantages of both UAE and surgical treatment for a large pedunculated fibroid.
Figure 1.
(A) Baseline T1-weighted post-gadolinium MR image in the sagittal plane showing a multifibroid uterus with a dominant 19 cm pedunculated fibroid arising from the uterine fundus. (B) Pre-procedural contrast-enhanced MR angiography demonstrating hypertrophied bilateral uterine arteries. No definite ovarian arterial supply is identified.
Table 1.
Advantages and disadvantages of UAE and surgical treatment for a large pedunculated fibroid.
| UAE | Laparoscopic Vessel Occlusion with Mini-Laparotomy Myomectomy | |
|---|---|---|
| Advantages | Minimally invasive; uterus-preserving; no general anesthesia; short recovery; might treat all fibroids in one session | Definitive removal of the dominant fibroid; histological diagnosis |
| Disadvantages | Lower efficacy in large or pedunculated fibroids; incomplete infarction from extra-uterine collaterals that may not be visible on pre-procedural imaging; possible re-intervention or adjunctive hormonal therapy | General anesthesia; blood loss from a hypervascular fibroid; longer recovery; perioperative thromboembolic risk; smaller intramural fibroids may remain untreated |
Via left distal radial access, each uterine artery was selectively catheterized with a 4-F catheter and a 2.9-F microcatheter. Intraprocedural digital subtraction angiography (DSA) confirmed hypertrophied uterine arteries with prominent vascular supply to the fibroid (Figure 2). Embolization was performed using 500–700 and 700–900 µm Embosphere microspheres. Post-embolization angiography demonstrated technically successful embolization with markedly reduced arterial flow and stasis in the uterine arteries, and no visible ovarian collaterals were identified (Figure 2).
Figure 2.
Intraprocedural digital subtraction angiography (DSA) images of the right and left uterine arteries before (A,B) and after (C,D) embolization. Pre-embolization images (A,B) demonstrate hypertrophied uterine arteries with prominent vascular supply to the fibroid. Post-embolization images (C,D) show technically successful embolization with markedly reduced arterial flow.
At the 3-month follow-up visit, the patient reported persistent menorrhagia and pelvic pressure. Post-embolization MRI demonstrated successful infarction of the smaller intramural and submucosal fibroids; however, the dominant 19 cm pedunculated fibroid remained largely vascularized with continued contrast enhancement (Figure 3). Thus, despite technically successful embolization of both uterine arteries, treatment of the dominant fibroid had failed.
Figure 3.
T1-weighted post-gadolinium MR image in the sagittal plane demonstrating successful devascularization of multiple intramural and submucosal uterine fibroids. In contrast, the dominant 19 cm pedunculated fibroid remains largely vascularized.
Subsequent CT angiography revealed aberrant parasitic arterial supply to the dominant fibroid: branches from the celiac axis and gastroduodenal artery (GDA) primarily supplied the right and anterior portions, while branches from the SMA supplied the left aspect of the fibroid (Figure 4). These collateral pathways were not apparent on pre-procedural imaging.
Figure 4.
Three-dimensional volume-rendered CT angiography image, demonstrating aberrant parasitic arterial supply to the dominant pedunculated fibroid. Branches from the celiac axis and gastroduodenal artery (GDA) primarily supply the right and anterior portions of the fibroid, while branches from the superior mesenteric artery (SMA) supply its left portion. White arrows indicate the celiac axis, GDA and SMA; yellow arrows indicate the fibroid feeders.
Following UAE, the patient developed a pulmonary embolism unrelated to the procedure 4 months after UAE, for which therapeutic anticoagulation was started. Owing to elevated perioperative thromboembolic and bleeding risk following a recent pulmonary embolism, surgical intervention was deferred. Additional selective embolization was considered for preoperative devascularization before surgical resection, but was not pursued because of delayed surgery. Embolization alone was not deemed a sufficient treatment. The patient was started on gonadotropin-releasing hormone (GnRH) agonist therapy as a bridge to delayed surgery.
Follow-up contrast-enhanced CT demonstrated interval reduction in fibroid size to 15 cm, although persistent parasitic vascularity remained evident (Figure 5). The patient experienced partial symptomatic improvement, and surgical options continue to be reassessed.
Figure 5.
Follow-up contrast-enhanced CT sagittal image demonstrating interval reduction in the size of the pedunculated uterine fibroid to 15 cm following GnRH agonist therapy.
3. Discussion
Uterine artery embolization is widely accepted as a safe and effective alternative to surgery for symptomatic fibroids, with clinical success rates approaching 90% in appropriately selected patients [1,2]. However, failure of symptom resolution following technically successful embolization raises concern for incomplete fibroid infarction, most often due to collateral blood supply. While the ovarian arteries are the most frequently identified source of extra-uterine perfusion, less common contributors include branches of the IMA and SMA [3,4,5].
This case illustrates a rare instance of UAE failure due to parasitic vascularization from both the celiac axis and SMA—a combination that, to our knowledge, has not been adequately described in the literature. Prior reports have documented aberrant fibroid supply from the IMA [4,5] and SMA [3] individually, and these collateral pathways appear to be recruited preferentially by large or pedunculated fibroids whose peripheral regions extend beyond the uterine arterial territory. In such cases, the uterine arteries may not represent the dominant vascular supply, and embolization confined to them alone may result in persistent fibroid viability.
Cross-sectional vascular imaging, particularly contrast-enhanced CT angiography and MR angiography, is crucial in evaluating treatment failure following UAE [6]. In this patient, CT angiography revealed persistent perfusion from gastroduodenal arterial branches—findings not apparent during the initial embolization procedure. Identification of such atypical feeders is essential for guiding further intervention, whether through targeted embolization of the collateral vessels or surgical planning.
Table 2 summarizes the published case reports and relevant studies on aberrant arterial supply contributing to UAE failure. As shown, collateral supply from the IMA is the most frequently reported non-ovarian source, while SMA feeders remain exceedingly rare. The current case adds to this limited body of evidence by documenting a dual collateral pattern involving both the celiac axis and the SMA.
Table 2.
Case reports and relevant studies on aberrant arterial supply in UAE failures.
| Year | Authors | Study Objective | Type of Collateral | Imaging Modality | Clinical Relevance | Key Findings |
|---|---|---|---|---|---|---|
| 2014 | Song et al. [3] | Case report: SMA parasitic supply to fibroids | SMA | CT angiography and conventional angiography | Illustrates rare SMA parasitic supply; underscores need for comprehensive vascular assessment after UFE failure | SMA branches can sustain fibroid perfusion; selective embolization required |
| 2013 | Salazar et al. [8] | Impact of embolizing utero-ovarian anastomoses on symptoms and amenorrhea | Utero-ovarian anastomoses | Angiographic identification of UOAs | Supports embolization of UOAs to reduce symptom recurrence; reassures regarding amenorrhea risk | OAE reduces recurrence when UOAs are present; no increased amenorrhea risk |
| 2013 | Chang et al. [4] | Prevalence and risk factors of IMA collaterals in UFE | IMA | MR and conventional angiography | Highlights IMA collaterals in large uteri or adenomyosis | IMA collaterals present in 1.3% of cases; associated with larger uterine volume and adenomyosis |
| 2012 | Dixon et al. [5] | Case report: IMA collaterals following UFE | IMA | Conventional angiography | Emphasizes need for follow-up imaging; re-intervention is common after UFE | Successful embolization of IMA collaterals after prior UAE failure |
| 2010 | Horton et al. [9] | Case report: anatomical variant of ovarian artery supplying the uterus | Ovarian (variant anatomy) | Conventional Angiography | Alerts to rare ovarian artery variants; reinforces need for detailed angiographic review | Unusual ovarian artery anatomy supplying both the uterus and adrenal gland |
This case underscores the need for heightened vigilance in post-UAE follow-up, particularly in patients with persistent symptoms and large pedunculated fibroids. Pre-procedural cross-sectional imaging may not always identify atypical feeders, as these collateral pathways can develop or become hemodynamically significant after embolization of the dominant uterine arterial supply. When technically feasible, selective embolization of identified collateral vessels should be considered; however, the anatomical complexity of celiac and mesenteric branches may limit this approach and necessitate alternative strategies such as hormonal therapy or surgical intervention.
Pedunculated subserosal fibroids were historically regarded as a relative contraindication to UAE; although later series showed acceptable safety and efficacy [7,10], large fibroids are more prone to extra-uterine collateral recruitment and incomplete infarction [4]. Surgery, such as laparoscopic occlusion of the uterine vessels with mini-laparotomy myomectomy, is therefore a valid alternative, and in a randomized trial myomectomy achieved better quality of life than UAE at 2 years [11]. The advantages and disadvantages of both approaches are summarized in Table 1. Regarding medical therapy, long-acting gonadotropin-releasing hormone (GnRH) agonists (e.g., leuprolide acetate, as used in this case) are considered effective but their hypoestrogenic effects limit their application and might necessitate hormonal treatment [12]. Oral GnRH antagonists (e.g., relugolix combination therapy) are also now available [12].
4. Conclusions
This case highlights a rare and previously underreported pattern of incomplete uterine fibroid embolization due to dual parasitic arterial supply from the celiac axis and superior mesenteric artery. It underscores the importance of considering atypical collateral pathways in patients with persistent symptoms following technically successful embolization, particularly those with large pedunculated fibroids. Cross-sectional angiographic imaging plays a critical role in identifying extra-uterine feeders and guiding further management. A multidisciplinary approach remains essential to tailor treatment strategies in complex cases involving aberrant vascular anatomy and elevated surgical risk.
Acknowledgments
During the preparation of this manuscript, the authors used Claude (Anthropic; Claude Opus 4.7 and Claude Opus 5.5) for drafting assistance and language editing. The authors have reviewed and edited the output and take full responsibility for the content of this publication.
Author Contributions
Conceptualization, H.A. and M.G.; data curation, H.A.; writing—original draft preparation, H.A. and M.G.; writing—review and editing, M.G. and D.K.; visualization, H.A. and M.G.; supervision, D.K. All authors have read and agreed to the published version of the manuscript.
Institutional Review Board Statement
Ethical review and approval of this study were not required by the Research Ethics Board Vancouver General Hospital/the University of British Columbia. The patient’s information has been de-identified.
Informed Consent Statement
Written informed consent has been obtained from the patient to publish this paper.
Data Availability Statement
All data are included in this published article. A preprint of this article was published on https://doi.org/10.21203/rs.3.rs-7172065/v1.
Conflicts of Interest
The authors declare no conflicts of interest.
Funding Statement
This research received no external funding.
Footnotes
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
References
- 1.Kohi M.P., Spies J.B. Updates on uterine artery embolization. Semin. Interv. Radiol. 2018;35:048–055. doi: 10.1055/s-0038-1636521. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Toor S.S., Jaberi A., Macdonald D.B., McInnes M.D., Schweitzer M.E., Rasuli P. Complication rates and effectiveness of uterine artery embolization in the treatment of symptomatic leiomyomas: A systematic review and meta-analysis. Am. J. Roentgenol. 2012;199:1153–1163. doi: 10.2214/ajr.11.8362. [DOI] [PubMed] [Google Scholar]
- 3.Song C.I., McDermott M., Sclafani T., Charles H.W. Aberrant arterial supply to uterine fibroids from branches of the superior mesenteric artery. Cardiovasc. Interv. Radiol. 2014;37:1618–1624. doi: 10.1007/s00270-014-0858-5. [DOI] [PubMed] [Google Scholar]
- 4.Chang S., Lee M.S., Kim M.D., Yoon C.J., Jung D.C., Lee M., Park S.I., Won J.Y., Lee D.Y. Inferior mesenteric artery collaterals to the uterus during uterine artery embolization: Prevalence, risk factors, and clinical outcomes. J. Vasc. Interv. Radiol. 2013;24:1353–1360. doi: 10.1016/j.jvir.2013.05.049. [DOI] [PubMed] [Google Scholar]
- 5.Dixon S., Tapping C.R., Chuah P.S., Bratby M., Uberoi R., Anthony S. Successful fibroid embolization of pelvic and inferior mesenteric artery collaterals after previous uterine artery embolization. Acta Radiol. 2012;53:292–295. doi: 10.1258/ar.2011.110518. [DOI] [PubMed] [Google Scholar]
- 6.Lee M.S., Kim M.D., Lee M., Won J.Y., Park S.I., Lee D.Y., Lee K.-H. Contrast-enhanced MR angiography of uterine arteries for the prediction of ovarian artery embolization in 349 patients. J. Vasc. Interv. Radiol. 2012;23:1174–1179. doi: 10.1016/j.jvir.2012.06.015. [DOI] [PubMed] [Google Scholar]
- 7.Llewellyn O., Patel N.R., Mallon D., Quinn S.D., Hamady M. Uterine artery embolisation for women with giant versus non-giant uterine fibroids: A systematic review and meta-analysis. Cardiovasc. Interv. Radiol. 2020;43:684–693. doi: 10.1007/s00270-019-02359-7. [DOI] [PubMed] [Google Scholar]
- 8.Salazar G.M., Walker T.G., Conway R.F., Yeddula K., Wicky S., Waltman A.C., Kalva S.P. Embolization of angiographically visible type I and II utero-ovarian anastomoses during uterine artery embolization for fibroid tumors: Impact on symptom recurrence and permanent amenorrhea. J. Vasc. Interv. Radiol. 2013;24:1347–1352. doi: 10.1016/j.jvir.2013.05.043. [DOI] [PubMed] [Google Scholar]
- 9.Horton A., Patel U., Belli A. An unusual arterial supply to the uterus. A case report and review of anatomy-implications for uterine artery embolization. Clin. Radiol. 2010;65:1038–1042. doi: 10.1016/j.crad.2010.07.007. [DOI] [PubMed] [Google Scholar]
- 10.Margau R., Simons M.E., Rajan D.K., Hayeems E.B., Sniderman K.W., Tan K., Beecroft J.R., Kachura J.R. Outcomes after uterine artery embolization for pedunculated subserosal leiomyomas. J. Vasc. Interv. Radiol. 2008;19:657–661. doi: 10.1016/j.jvir.2007.11.022. [DOI] [PubMed] [Google Scholar]
- 11.Manyonda I., Belli A.-M., Lumsden M.-A., Moss J., McKinnon W., Middleton L.J., Cheed V., Wu O., Sirkeci F., Daniels J.P., et al. Uterine-artery embolization or myomectomy for uterine fibroids. N. Engl. J. Med. 2020;383:440–451. doi: 10.1056/nejmoa1914735. [DOI] [PubMed] [Google Scholar]
- 12.Al-Hendy A., Lukes A.S., Poindexter A.N., 3rd, Venturella R., Villarroel C., Critchley H.O.D., Li Y., McKain L., Ferreira J.C.A., Langenberg A.G.M., et al. Treatment of uterine fibroid symptoms with relugolix combination therapy. N. Engl. J. Med. 2021;384:630–642. doi: 10.1056/nejmoa2008283. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
All data are included in this published article. A preprint of this article was published on https://doi.org/10.21203/rs.3.rs-7172065/v1.