Contrast-enhanced ultrasound assessment of the therapeutic efficacy and treatment of a large renal artery aneurysm following multiple vascular reconstructions: a case description

Introduction

Renal artery aneurysms (RAAs) are relatively rare clinically, historically occurring in 0.01% of autopsies, with imaging studies revealing a prevalence of approximately 0.7–0.9%. The incidence notably rises in hypertensive patients (2.5%) and those with fibromuscular dysplasia (9.2%) (1,2).

Despite the low risk of RAAs rupturing, the consequences can be severe. Therefore, regular non-invasive monitoring is recommended when the aneurysm size exceeds 1.5 cm or when wall calcification is present (2).

The treatment of RAAs primarily involves interventional therapy and surgical procedures. Due to significant overall invasiveness, surgical procedures are currently less common. Endovascular therapy, with advantages such as minimal trauma, fast recovery, less pain, and fewer complications, has become widely used (3). However, the overall risk of complications associated with endovascular treatment, ranging from 16% to 30%, can be life-threatening. These risks encompass both vascular access and aneurysm treatment and highlight the critical importance of close imaging follow-up for timely detection and management (4,5). Digital subtraction angiography (DSA), the gold standard for diagnosis, is invasive. Metals interfere with computed tomography angiography (CTA), reducing diagnostic accuracy, and the iodinated contrast agents carry a risk of kidney injury. In comparison, contrast-enhanced ultrasound (CEUS) offers radiation-free, non-invasive, highly reproducible, and real-time imaging in multiple postsurgical follow-ups. By using low-volume, microbubble-based contrast agents, CEUS minimizes nephrotoxicity, offering a safer alternative for patients at risk of kidney damage.

This study utilized CEUS to monitor large RAAs that have resisted multiple interventional treatments. Ultimately, guided by CEUS, surgical treatment was adopted, resulting in a cure.

Case presentation

A 45-year-old female patient was discovered to have a right RAA during a routine physical examination over 10 years ago. She initially received coil embolization treatment at the Vascular Surgery Department of Peking Union Medical College Hospital, followed by yearly follow-up examinations. At 4 years post-treatment, she experienced dull pain in the right renal area. B-mode ultrasound at Beijing Hospital revealed dilation of the aneurysm in the upper and middle branches of the renal artery. Renal scintigraphy indicated normal renal function. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

The patient underwent a second coil embolization treatment at our vascular surgery department. Angiography during the procedure revealed a 6 cm × 6 cm secondary branch aneurysm of the right renal artery. Postoperative discomfort in the right renal area was relieved, and the aneurysm size was reduced to approximately 2.2 cm × 1.7 cm on ultrasound examination. A 6-month short-term follow-up using CEUS showed the aneurysm size to be approximately 5.4 cm × 4.1 cm with no blood flow perfusion. During the short-term follow-up conducted within the first 6 months after surgery, CEUS revealed significant changes in blood flow within the aneurysm after the embolization treatment, providing crucial guidance for further treatment.

At 10 months post-operation, a long-term CEUS follow-up revealed re-dilation of the right RAA to approximately 6.4 cm × 4.3 cm (Figure 1A), with visible blood flow within the aneurysm. The patient subsequently underwent a third coil embolization surgery following DSA diagnosis (Figure 1B). Two months post-surgery, angiography reexamination showed the aneurysm diameter had reduced to approximately 5 cm.

Figure 1 Sequential imaging of right RAA from treatment to three-year follow-up after surgery. (A) The CEUS follow-up revealed a renal artery aneurysm measuring approximately 6.4 cm × 4.3 cm; (B) intraoperative DSA demonstrated a right renal artery aneurysm post-coil embolization; (C) two years post-surgery, the CEUS follow-up demonstrated tortuous dilations in the right renal artery lumen near the renal hilum, with the widest point at approximately 1.2 cm; (D) three years post-surgery, CEUS follow-up indicated a width of about 0.56 cm at the onset of the right renal artery and 1.2 cm near the renal hilum. CEUS, contrast-enhanced ultrasound; DSA, digital subtraction angiography; RAA, renal artery aneurysm.

Despite three embolization surgeries, the stability and treatment effectiveness of the RAA became a concern. The aneurysm remained unstable and long-term control was not achieved.

Eventually, with the patient’s active cooperation in treatment, open surgery was selected for the resection of the right RAA and patch angioplasty. Routine ultrasound follow-ups at one week, one month, three months, and six months post-surgery demonstrated effective control of the aneurysm without significant blood flow signals.

Long-term follow-up with CEUS at one, two (Figure 1C), and three years (Figure 1D) after open surgery indicated good control of the large aneurysm located at the upper pole of the right kidney, with the widest point at the renal hilum being 1.2 cm. The renal parenchyma of the right upper pole appeared relatively thin with poor perfusion. No other significant complications were observed during the multiple routine ultrasound and CEUS follow-ups. During the long-term follow-up, CEUS was revealed to be more patient-friendly and efficient, accurately assessing the size and blood flow characteristics of the aneurysm, thereby aiding in guiding subsequent treatment decisions (6,7).

Discussion

This case of a 45-year-old female with recurrent RAA underscores the vital role of CEUS in RAA management. The utility of CEUS is highlighted and supported by contemporary literature. Its non-invasiveness and efficiency in assessing aneurysm size and blood flow dynamics post-treatment are crucial for treatment evaluation and decision-making (7,8).

The findings from this case align with the guidelines presented in “The Society for Vascular Surgery clinical practice guidelines on the management of visceral aneurysms” (8), which emphasize the importance of a detailed imaging approach for accurate diagnosis and follow-up of RAAs. The case reflects the evolving landscape of RAA management, where multi-modal imaging techniques, including CEUS, play a pivotal role in optimizing patient outcomes.

This patient’s journey, involving multiple coil embolization procedures followed by an eventual shift to surgical intervention, reflects the complexities and challenges in managing refractory RAAs. In line with the insights offered by the various studies reviewed, including the large-scale study on CTA and its effectiveness (9), this case illustrates the dynamic nature of RAA management. The decision to transition from an endovascular to open surgical approach was guided by CEUS findings.

Despite advancements in endovascular techniques, as discussed in the multi-center study on CTA, this case demonstrates the necessity for individualized treatment plans, especially in complex and recurrent cases (10). The long-term monitoring with CEUS, evident in this case, aligns with current guidelines which advocate for regular follow-up to monitor aneurysm stability and identify any changes that may warrant further intervention (11). A previous study has shown that compared to Doppler ultrasound, internal leakage can be missed by DSA monitoring by up to 9% (11). CEUS is not only radiation-free, safer, more convenient, cheaper, and more cost-effective than CTA and DSA, but also uses microbubble contrast with minimal intravenous requirements, making it widely applied and increasingly available in high-level hospitals (12).

Conclusions

This case underscores the importance of CEUS in RAA management, aligning with current literature and guidelines advocating for a comprehensive, adaptable imaging strategy. It underscores the necessity of integrating various imaging modalities, with a particular emphasis on the utility of CEUS, in both the short-term and long-term management of RAAs. This comprehensive approach is crucial for optimizing the prognosis of patients with complex vascular diseases such as RAA.

Acknowledgments

None.

Footnote

Funding: This study was supported by the National High Level Hospital Clinical Research Funding (No. BJ-2018-198), Beijing Science and Technology Project (No. Z211100002921011), and the National High Level Hospital Clinical Research Funding (No. BJ-2023-096).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-24-2055/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Schwartz CJ, White TA. Aneurysm of the renal artery. J Pathol Bacteriol 1965;89:349-56. [Crossref] [PubMed]
2. Zhang LJ, Yang GF, Qi J, Shen W. Renal artery aneurysm: diagnosis and surveillance with multidetector-row computed tomography. Acta Radiol 2007;48:274-9. [Crossref] [PubMed]
3. Spampinato B, Settembrini AM, Romagnoli S, D'Alessio I, Domanin M, Gabrielli L. Concomitant Renal Artery and Aortic Aneurysm: Is Endovascular Surgery the Correct Approach? Ann Vasc Surg 2019;61:473.e1-5. [Crossref] [PubMed]
4. Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial. Lancet 2005;365:2187-92. [Crossref] [PubMed]
5. Gozzo C, Caruana G, Cannella R, Farina A, Giambelluca D, Dinoto E, Vernuccio F, Basile A, Midiri M. CT angiography for the assessment of EVAR complications: a pictorial review. Insights Imaging 2022;13:5. [Crossref] [PubMed]
6. Granata A, Floccari F, Clementi A, Di Lullo L, Fiorini F. Contrast-enhanced ultrasound reveals renal artery aneurysm after detection of 'parapelvic lithiasis'. Clin Exp Nephrol 2014;18:174-5. [Crossref] [PubMed]
7. Chaer RA, Abularrage CJ, Coleman DM, Eslami MH, Kashyap VS, Rockman C, Murad MH. The Society for Vascular Surgery clinical practice guidelines on the management of visceral aneurysms. J Vasc Surg 2020;72:3S-39S. [Crossref] [PubMed]
8. Rogers S, Lowe C, Carreira J, McCollum C, Ghosh J. Comparison of Contrast-Enhanced Tomographic 3-D Ultrasound Against Rotational Angiography Imaging Immediately After Endovascular Aneurysm Repair. Ultrasound Med Biol 2019;45:2356-62. [Crossref] [PubMed]
9. Klausner JQ, Lawrence PF, Harlander-Locke MP, Coleman DM, Stanley JC, Fujimura NVascular Low-Frequency Disease Consortium. The contemporary management of renal artery aneurysms. J Vasc Surg 2015;61:978-84. [Crossref] [PubMed]
10. Rezq A, Pitì A, Martelli E, De Luca F, Sangiorgi G. Renal artery side branches patency protection during endovascular exclusion of giant renal artery aneurysm with covered stent: Well done is better than well said. J Cardiol Cases 2019;20:11-3. [Crossref] [PubMed]
11. Sandford RM, Batchelder AJ, Bown MJ, Sayers RD. Pre-discharge duplex ultrasound scans detect endoleaks not seen on completion angiography after endovascular aneurysm repair. J Endovasc Ther 2010;17:349-53. [Crossref] [PubMed]
12. Faccioli N, Foti G, Casagranda G, Santi E, D'Onofrio M. CEUS versus CT Angiography in the follow-up of abdominal aortic endoprostheses: diagnostic accuracy and activity-based cost analysis. Radiol Med 2018;123:904-9. [Crossref] [PubMed]