Healing response in elastase-induced rabbit aneurysms after embolization with a new platinum coil system

AJNR Am J Neuroradiol. 2002 Aug;23(7):1137-44.


Background and purpose: Elastase-induced rabbit aneurysms offer promise in preclinical testing, but their radiographic and histologic features after dense packing with platinum coils are unknown. We evaluated these features by using a new platinum coil system.

Methods: Right common carotid arterial (CCA) aneurysms were created in 17 rabbits by distal ligation and intraluminal elastase incubation. At least 3 weeks later, aneurysms were packed with detachable platinum coils. Animals were sacrificed at 2 (group 1, n=4), 4 (group 2, n=5), 12 (group 3, n=4), or 24 (group 4, n=4) weeks. Aneurysmal occlusion and coil compaction were angiographically assessed. Histologic features of tissue covering the coils and the aneurysmal dome were assessed and semiquantitatively compared across groups.

Results: No notable tracking, deployment, or detachment problems occurred. Volumetric occlusion was 5-49% (mean, 26.8% +/- 11%). Angiographic occlusion was 100% in six cases, 95% in four, and 90% in seven; occlusion scores remained unchanged in 13 cases, decreased in one, and increased in two (one case excluded from angiographic follow-up). Histologic findings were concordant within groups. Group 1 had coverage with thin fibrin layers and scattered leukocytes; group 2, some spindle-cell coverage; group 3, spindle-cell coverage. In groups 1 and 2, dome findings included only unorganized blood products. In group 3, blood products had been replaced with a hypocellular, poorly staining matrix. Some group 4 subjects had variably aged blood products, with tissue of limited organization.

Conclusion: The platinum coil system performed well in experimental aneurysmal embolization. Densely packed rabbit aneurysms demonstrate reproducible histologic evolution: early fibrin coverage, delayed spindle-cell coverage, delayed intraaneurysmal thrombus resorption, and occasional coil compaction.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carotid Artery, Common / diagnostic imaging
  • Carotid Artery, Common / pathology
  • Disease Models, Animal
  • Embolization, Therapeutic / instrumentation*
  • Equipment Design
  • Equipment Safety
  • Follow-Up Studies
  • Intracranial Aneurysm / chemically induced*
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / physiopathology*
  • Pancreatic Elastase / adverse effects*
  • Platinum / therapeutic use*
  • Rabbits
  • Radiography
  • Wound Healing / physiology*


  • Platinum
  • Pancreatic Elastase