Purpose: Although benign, aneurysmal bone cysts (ABCs) are expansile, osteolytic vascular
malformations of bone that when located in the spine often cause severe pain and deformity,
occasionally presenting with neurologic deficit or cord compression. Although traditionally
treated with curettage or en bloc resection, over the last decade, targeted treatment
with sclerosing agents has been advocated.
The purpose of our study was to establish the efficacy and safety profile of sodium
tetradecyl sulfate foam (Fibrovein 3%) in the percutaneous treatment of aggressive
spinal ABCs with pain and/or neurologic compromise.
Methods and Materials: Between July 2015 and January 2020, eight consecutive patients (5 males and 3 females;
mean age: 24 years [range: 9–53]) were recruited from a single regional sarcoma unit,
following histologic and radiologic confirmation, with unanimous agreement on treatment
strategy by the multidisciplinary tumor board. All patients had spinal ABCs, pain,
and/or neurologic compromise with imaging and clinical evidence of cord compression
in three of the eight patients and neural compression/irritation in four of the eight.
All were treated with single or repeated treatment cycles using fluoroscopic or computed
tomography (CT)-guided percutaneous intraosseous injection of sodium tetradecyl sulfate
foam. The clinical and imaging longitudinal follow-up period was up to 4 years. Procedural
data, patient demographics, tumor characteristics, and functional outcomes were recorded.
Results: Technical success was achieved in all cases. Mean procedure length for fluoroscopy
was 10 minutes (range: 7–17), compared with 33 minutes (range: 12–54) for CT; one
to five treatment cycles (mean: 2.6) were performed using a mean of 2.7 mL (range:
1–6 mL) 3% sodium tetradecyl sulfate foam. Mean dose per procedure was 165 dose length
product (DLP) (range: 52–331). Mean spine instability neoplastic score was 10 (range:
7–14). An average follow-up period of 18 months (range: 3–41) was undertaken. In two
patients, neurologic compromise persisted after sclerotherapy, due to persistent cord
compression requiring emergency en bloc resection and thus was only included in procedural
data analysis. All remaining patients demonstrated a significant reduction in pain:
presurgical mean of 8.3 (range: 8–9 from a 10-point numerical pain score) to a mean
of 3 (range: 2–7) after sclerotherapy (p = 0.04) and a significant percentage reduction in cyst volume (mean: 0.62; range:
0.27–0.91) on serial follow-up magnetic resonance imaging (MRI) (p = 0.009).
Conclusion: Image-guided percutaneous intralesional injection of sodium tetradecyl sulfate foam
is a safe, technically feasible, minimally invasive, and effective first-line treatment
of primary spinal ABCs causing pain and neurologic compromise. Even if surgery is
required, our sclerotherapy technique contributes to reduced intraoperative blood
loss. In our experience, early injection, particularly in large lesions with repeated
treatment cycles, avoids the requirement for extensive debilitating spinal surgery
in pediatric and young adult patients.
Fig. 1 (a) Sacral aneurysmal bone cysts compressing the left S1 nerve in a young male patient.
(b) Volumetric magnetic resonance imaging segmentation analysis after initial cycle
of sclerotherapy revealed a 30% reduction in cyst volume.
Fig. 2 (a) Axial and (b) sagittal computed tomography (CT). (c, d) Sagittal and axial magnetic resonance imaging (MRI) short tau inversion recovery
sequences through a T6 aneurysmal bone cyst that demonstrates progressive consolidation
of the lesion, depicted by increased density on CT and low signal on MRI.
Fig. 3 Sequential computed tomography scans performed in an 18-year-old male patient with
an aneurysmal bone cyst at L4 (spine instability neoplastic score: 10). After four
cycles of sclerotherapy with sodium tetradecyl sulfate foam, there was significant
reduction in pain and a 78% reduction in cyst volume with osseous consolidation.
