Endovascular coil embolization of segmental arteries prevents paraplegia after subsequent thoracoabdominal aneurysm repair: an experimental model

J Thorac Cardiovasc Surg. 2014 Jan;147(1):220-6. doi: 10.1016/j.jtcvs.2013.09.022. Epub 2013 Nov 9.

Abstract

Objectives: To test a strategy for minimizing ischemic spinal cord injury after extensive thoracoabdominal aneurysm (TAAA) repair, we occluded a small number of segmental arteries (SAs) endovascularly 1 week before simulated aneurysm repair in an experimental model.

Methods: Thirty juvenile Yorkshire pigs (25.2 ± 1.7 kg) were randomized into 3 groups. All SAs, both intercostal and lumbar, were killed by a combination of surgical ligation of the lumbar SAs and occlusion of intercostal SAs with thoracic endovascular stent grafting. Seven to 10 days before this simulated TAAA replacement, SAs in the lower thoracic/upper lumbar region were occluded using embolization coils: 1.5 ± 0.5 SAs in group 1 (T13/L1), and 4.5 ± 0.5 SAs in group 2 (T11-L3). No SAs were coiled in the controls. Hind limb function was evaluated blindly from daily videotapes using a modified Tarlov score (0 = paraplegia, 9 = full recovery). After death, each segment of spinal cord was graded histologically using the 9-point Kleinman score (0 = normal, 8 = complete necrosis).

Results: Hind limb function remained normal after coil embolization. After simulated TAAA repair, paraplegia occurred in 6 of 10 control pigs, but in only 2 of 10 pigs in group 1; no pigs in group 2 had a spinal cord injury. Tarlov scores were significantly better in group 2 (control vs group 1, P = .06; control vs group 2, P = .0002; group 1 vs group 2, P = .05). A dramatic reduction in histologic damage, most prominently in the coiled region, was seen when SAs were embolized before simulated TAAA repair.

Conclusions: Endovascular coiling of 2 to 4 SAs prevented paraplegia in an experimental model of extensive hybrid TAAA repair, and helped protect the spinal cord from ischemic histopathologic injury. A clinical trial in a selected patient population at high risk for postoperative spinal cord injury may be appropriate.

Keywords: 26.1; MAP; SA; TAAA; mean arterial pressure; segmental artery; thoracoabdominal aortic aneurysm.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Aortic Aneurysm, Thoracic / surgery*
  • Blood Vessel Prosthesis Implantation / adverse effects*
  • Embolization, Therapeutic*
  • Endovascular Procedures / adverse effects*
  • Hindlimb
  • Lumbosacral Region / blood supply*
  • Models, Animal
  • Muscle, Skeletal / blood supply*
  • Paraplegia / etiology
  • Paraplegia / physiopathology
  • Paraplegia / prevention & control*
  • Recovery of Function
  • Regional Blood Flow
  • Spinal Cord Ischemia / etiology
  • Spinal Cord Ischemia / pathology
  • Spinal Cord Ischemia / physiopathology
  • Spinal Cord Ischemia / prevention & control*
  • Swine
  • Thoracic Arteries*
  • Time Factors
  • Video Recording