Combined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts

Clinical question
To evaluate the use of combined transarterial embolization (TAE) and percutaneous sclerotherapy in the treatment of nonresectable and refractory aneurysmal bone cysts (ABCs).

 
Take away point
Combined TAE and percutaneous sclerotherapy is a minimally invasive, safe, and effective procedure that can be used to treat nonresectable ABCs and to significantly improve patients’ quality of life.

Reference
Masthoff M, Gerwing M, Schneider KN, et al. Combined Transarterial Embolization and Percutaneous Sclerotherapy as Treatment for Refractory and Nonresectable Aneurysmal Bone Cysts. J Vasc Interv Radiol. 2021;32(10):1425-1434.e2. doi:10.1016/j.jvir.2021.07.008

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Study design
Retrospective, single-center, observational study that included patients with refractory and nonresectable ABCs treated with combined TAE and percutaneous sclerotherapy. Decision to treat with combined selective TAE and percutaneous sclerotherapy was made by an interdisciplinary board.

Funding Source
No reported funding.

Setting
Academic setting. University Hospital Münster, Münster, Germany; University Hospital Essen, Essan, Germany; University Hospital Ludwig Maximilian University of Munich, Munich, Germany.

Figure



Flow scheme of the treatment algorithm for combined transarterial embolization and percutaneous sclerotherapy for refractory and nonresectable ABCs.

(a) and (b) Representative images of transarterial embolization of an aneurysmal bone cyst (ABC) of the left clavicle. Angiography showed arterial hypervascularization of an ABC (a, black arrowheads) with arterial feeding vessels from the axillary artery. Superselective embolization of the feeding vessels led to the complete embolization of the ABC, while the axillary artery was successfully spared. (c) Representative fluoroscopic imaging of percutaneous sclerotherapy after transarterial embolization followed by administration of the sclerosing agent via the percutaneous bone access needle (white asterisk). (d) Baseline T2 axial magnetic resonance (MR) imaging showed the typical appearance of an ABC (white arrowhead) with T2 hyperintense, partially blood-filled cysts. (e) Follow-up T2 axial MR imaging scan after treatment showed a heavily reduced number and size of cysts (white arrowhead) with complete mineralization of the ABC. (f) Baseline radiograph showed the typical osteolytic, multicystic appearance of an ABC of the left clavicle. (g) Follow-up radiograph showed complete mineralization of the ABC after combined transarterial embolization and percutaneous sclerotherapy.

Summary

ABCs are rare osseous lesions that tend to occur in people under the age of 20. Symptoms may include pain, swelling, neurologic symptoms due to local nerve compression, movement restriction, or pathologic fractures. The goal of ABC therapy is to eradicate neoplastic tissue and enable remineralization. The mainstay treatment has been complete intralesional curettage or excision and filling. Alternatives including TAE, percutaneous sclerotherapy, or denosumab therapy have also been used.

The authors preformed a retrospective review of 16 consecutive patients who were treated with combined TAE and percutaneous sclerotherapy for refractory and nonresectable ABCs. Median age of the patients was 17 years. Only 1 of the patients had a history of pathologic fracture at the initial presentation. Seven of the patients had not undergone any previous therapies for ABC, one had a prior curettage, and none had undergone any systemic therapies. Data collected by the investigators included radiographic and magnetic resonance (MR) imaging, in addition to quality-of-life assessments which were performed prior to the first and at least 4 weeks after the final intervention. The median follow-up was 27.3 months. Two radiologists who were blinded to the interventions independently assessed the imaging data for several variables: number of intralesional cysts, size of the largest cyst, occurrence of pathologic fractures, grade of intralesional mineralization (using a 5-point Likert scale), and grade of lesion fluid-fluid levels (using a 4-point Likert scale established in the literature). TAE and percutaneous sclerotherapy treatment sessions were performed sequentially. TAE was used to achieve complete arterial devascularization and percutaneous sclerotherapy followed TAE until either ABC necrosis was achieved (using diminished lesional contrast enhancement as a marker) or clinical symptom relief was attained.

The interventional procedures were performed under general anesthesia. Feeding vessels of the ABCs were embolized using EVOH (Onyx Liquid Embolic System). During the same session, multiple percutaneous accesses into a majority of the ABC cavities were achieved under fluoroscopic guidance. Sclerotherapy was performed by injecting DiscoGel, which contained gelified 96% ethyl alcohol, cellulose derivative product, and tungsten and polidocanol. The investigators used 2 standardized outcome parameters, the Musculoskeletal Tumor Society (MSTS) score and the 36-Item Short Form Survey (SF-36), to assess clinical outcome and quality of life. For both these parameters, higher scores represent a higher quality of life.

Clinical Outcome – Imaging Data

Overall, a mean of 1.6 ± 0.7 TAEs and 3.2 ± 1.7 percutaneous sclerotherapies were performed with a technical success rate of 100%. Complete or subtotal, defined as >90% of arterial feeding vessels, was achieved in all patients. No adverse events were reported during the procedures and no procedure-associated long-term adverse events were observed at follow-up. Follow-up imaging scans showed a decreased number of intralesional cysts in 15/16 patients and a decreased cyst size in 14/16 patients. ABC lesion mineralization significantly increased while the fluid-fluid levels of the ABCs significantly decreased (P < .0001). All 9 patients who received contrast-enhanced follow-up MR imaging showed either complete (1) or partial response (8) to treatment. There was also a significant reduction in mean contrast-enhanced lesion size following therapy (P = .0003). There was no pathologic fracture development during the follow-up period and no patient had ABC recurrence after the initial treatment response. One patient became a surgical candidate after intervention led to ABC downstaging, and one patient was switched to denosumab therapy after showing prolonged partial response.

Clinical Outcome – Quality of Life

Both scoring systems, the MSTS score and the SF-36 survey, showed significantly improved quality of life scores. The MSTS score increased to 28.8 ± 1.8 from a baseline of 14.1 ± 8.6 (P < .0001). Similarly, the SF-36 physical functioning score improved from 44.3 ± 32.3 to 93 ± 13.5 (P <.0001) while the SF-36 score for role limitations due to physical health improved from 23.3 ± 40.6 to 93.3 ± 25.8 (P < .0001). Only 1 patient did not demonstrate significant improvement in both SF-36 categories. The SF-36 also assesses the effects of physical disease on mental health; all mental health-associated categories demonstrated significant improvement (P < .001). Social functioning (P = .0004), pain (P < .0001), and outlook on future health (P < .0001) all significantly improved. Overall, the MSTS and SF-36 scores demonstrated a clinical success rate of 93.8% in improved quality of life.

Commentary

The authors of this study demonstrated the efficacy and safety of combined TAE and percutaneous sclerotherapy for the treatment of refractory and nonresectable ABCs. The similar success rate of this minimally-invasive intervention to primary surgery may warrant further investigation into using combined TAE and percutaneous sclerotherapy in new contexts; either as primary treatment in resectable ABCs or to downstage lesions to facilitate future surgery. Additionally, the lack of ABC recurrence during the median follow up of 27.3 months demonstrates the superior durability of this method compared to other treatment strategies. There are several limitations to this study, including but not limited to its retrospective nature, the lack of control group, heterogenous distribution of ABC lesions, lack of standardized response criteria for bone lesions, and failure to perform contrast-enhanced follow-up MR imaging on each patient. In spite of these limitations, this study is important because adds credence to the idea that the pathogenesis of ABCs stems from dysplastic vessels and neoplastic cell proliferation. Current treatment options for ABCs tend to favor a surgical approach; however, applying the treatment strategies in this study to a wider range of ABC patients, initially in a prospective trial setting for clinical validation, may improve overall clinical outcomes.

Post Author
Kaelan Chan
Medical Student, MS4
University of Cincinnati College of Medicine

Edited and Formatted by @NingchengLi

Interventional Radiology Resident

Dotter Institute, Oregon Health and Science University