Direct percutaneous EthiblocTM injection in the treatment of Aneurysmal Bone Cysts: long term follow

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Direct percutaneous EthiblocTM injection in the
treatment of Aneurysmal Bone Cysts long term
follow-up
G. La Rosa, P. Falappa, F.M. Fassari, A. Di
Lazzaro, R. Devito, E. Genovese
From Bambino Gesu Paediatric Hospital
Rome Paediatric Surgery Dept.- Orthopaedic
Unit - Palidoro Radiology Dept. - Rome
Specialistic Surgery Dept. - Orthopaedic Unit -
Rome
Laboratories Dept.- Pathology Unit - Rome
Medical Phisycs Dept - Rome
European Paediatric Orthopaedic Society
Sorrento ( Italy ) 11-14 April 2007
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• Traditional treatment of Aneurysmal Bone Cysts
  (A.B.C.) in easily reachable sites is invasive
  surgery, with many variations.
• Minimally invasive treatments were recently
  proposed, as arterial embolization and direct
  percutaneous injection
• (Adamsbaum 1993).
• EthiblocTM technique has been used in our
  Institution since 1994.
• Before embolization it is mandatory to obtain a
  biopsy, by means of a flexible forceps introduced
  via percutaneous needle 8-10G.

Histologic view showing Aneurysmal Bone Cyst
Intraoperatory tissue sampling by means of biopsy
forceps
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Materials and Methods

• Treatment consists in direct, percutaneous or
  CT-guided, injection of EthiblocTM (a viscous
  association of sclerosant and embolic drugs
  causing intravenous thrombosis,intense local
  inflammatory reaction and fibrosis).

Treatment results were assessed by pain
disappearing, if present, and by x-ray, CT scan
and MRI, evaluating 1.Endosteal bone
reconstruction (cancellous and cortical bone)
2.Cyst cavity reduction 3. Bone tissue filling
cystic cavity
Pre-filled delivery syringe ready to inject
Endocavitary EthiblocTM injection (double needle
technique)
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Personal Experience (1994 - 2006)

• 50 patients with A.B.C. assessed by biopsy (26
  males-24 females, age 5-25yrs) have been treated
  by EthiblocTM embolization.
• 8 patients have previously been treated
  surgically, without success.
• 5 patients were treated by only one embolization.
  In the other cases the procedure has been
  repeated 2 to 4 times.
• 2 patients presented unsatisfactory results and
  were consequently treated by surgery.

Mean follow-up was 6,7 years (range 6-101 months)
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Case 1 A Pre-treatment femur x-ray of a
16-year-old female showing a large A.B.C. B
MRI SE T2 weighted before treatment. C X-ray
after four EthiblocTM endocavitary injection at
the last follow-up (after 9 years). D MRI SE T2
weighted at the last follow-up.
Case 2 A Humeral A.B.C. in a 9-year-old boy
the cyst is close to phiseal line of growth. B
Intraoperative fluoroscopic view during filling
of the cyst with EthiblocTM ( double needles
technique). C X-Ray control at the last
follow-up, seven years later.
A
C
B
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Case 3 A CT scan showing A.B.C. in the ischiatic
bone in a 5-year-old boy (solid arrows). B
Intraoperative CT scan image during EthiblocTM
injection (patient in prone position).
C X-ray one day after injection showing local
distribution of embolizing material. D CT scan
after four years. E The last x-ray after six
years.
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Case 4
A X-ray in AP of a tibial A.B.C. in a
15-year-old girl. B Pre-treatment x-ray in
lateral view. C Evidence of fluid-fluid levels
(arrows) at MRI.
D Intraoperative fluoroscopic image during
intracystic EthiblocTM injection with a 10G
needle (solid arrow). Lateral view.E F Follow-up
x-ray after five years. Lateral and AP
projections.
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Case 5
A A very large, aggressive clavicle A.B.C.
(arrows) in a 7-year-old girl. B Cyst MRI
showing fluid-fluid levels in the preoperative
study.
C Intraoperative fluoroscopic image during
Ethibloc injection. D X-ray after three years.
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Results 48 patients (96) showed remarkable
shrinkage of cystic lesions with cortical
thickening. Pain disappeared in 41 patients,
persisted in two (non responding patients) and
occurred occasionally in seven.
Complications we observed reduced growth in
length in one case of an humeral cyst (growth
cartilage damage due to treatment or cyst?).
Side effects Fever,transient local pain and
limited Ethibloc leakage in soft tissues,
self-resolving without sequelae.
A rare case of epiphiseal extension of A.B.C.
(arrow), usually metaphyseal.This boy showed a
limited grow in the affected arm after
embolization, due to a disturbance of growth
cartilage possibly caused by the epiphiseal cyst.
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Conclusions
Direct percutaneous A.B.C. embolyzation with
Ethibloc

• It is a very effective procedure (total remission
  in 96, in our experience).
• It is less invasive of any other operative
  procedure.
• Does not preclude any subsequent surgical
  treatment.
• Does not cause cutaneous scars.

We propose embolization as the first choice
treatment in A.B.C. that are difficult to reach
even in safer sites it can be recommended as an
effective minimally invasive treatment option.