Embolization and endothelial ablation with chitosan and sodium sotradecol sulfate: preliminary results in an animal model.
OBJECTIVE
To investigate whether embolization with chitosan hydrogel (CH) with or without a sclerosant (sodium tetradecyl sulphate, STS) can induce chemical endothelial ablation and prevent endothelial recanalization in a rabbit model.


METHODS
Chitosan radiopaque thermogels were prepared using chitosan, β-glycerophosphate, iopamidol, and different STS concentrations. Each auricular artery of 14 New Zealand White rabbits was cannulated and injected with 0.6 mL of chitosan (CH0; n = 14) on one side and either saline (n = 3), chitosan and 1% STS (CH1; n = 6), or chitosan and 3% STS (CH3; n = 6) in the contralateral side. Immediately after embolization and at 1, 7, 14, and 30 days, auricular artery patency and percentage of recanalization were assessed by visual inspection; microcirculation was evaluated using laser Doppler imaging (LDI). The rabbits were sacrificed at 30 days to assess endothelial ablation and inflammatory response by histological analyses.


RESULTS
All arteries were catheterized and embolized with success. All saline-injected arteries rapidly recovered normal flow. The length of embolization was greater with CH3 than CH1 or CH0, regardless of the time observed (p<0.001). No difference in recanalization length was found among the gels (p = 0.07). Destruction of arterial wall was frequently observed independent of embolizing agent. Foreign body reaction was more frequent with CH3 as compared with CH1 and CH0 (p = 0.0070 and 0.0058, respectively). After 30 days, hypervascularization was observed on LDI only with CH0; it was attributed to intra- or perivascular neovessels and inflammatory response on pathological analysis. The vascular modifications appeared to be more homogenous across the length of embolization with CH3 than the other formulations.


CONCLUSIONS
The viscosity obtained with chitosan and 3% STS permits better control during injection and longer vascular occlusion. These findings, combined with the intravascular neovascularization observed with CH0, led us to prefer the combination with STS.
Service de Radiologie, CHU Clermont-Ferrand, France.
Pascal
P
Chabrot
Ahmed
A
Fatimi
Patrizio Delli
PD
Fraine
Lemlih
L
Ouchchane
Marie-Mélanie
MM
Dauplat
Alain
A
Rivard
Sophie
S
Lerouge
Gilles
G
Soulez
D055011:Ablation Techniques / Q000009:adverse effects; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D048271:Chitosan / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004423:Ear / Q000098:blood supply*; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000379:methods*; D042783:Endothelial Cells / Q000187:drug effects* / Q000473:pathology; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology; D020100:Hydrogels; D007269:Injections, Intra-Arterial; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation; D023421:Models, Animal; D009389:Neovascularization, Pathologic; D011817:Rabbits; D012039:Regional Blood Flow; D012597:Sclerosing Solutions / Q000008:administration & dosage* / Q000009:adverse effects; D012981:Sodium Tetradecyl Sulfate / Q000008:administration & dosage* / Q000009:adverse effects; D013997:Time Factors; D014654:Vascular Patency; D014783:Viscosity
D020100:Hydrogels; D012597:Sclerosing Solutions; D048271:Chitosan; D012981:Sodium Tetradecyl Sulfate