Assessment of spinal cord integrity during thoracoabdominal aortic aneurysm repair

Ann Thorac Surg. 2002 Nov;74(5):S1864-6; discussion S1892-8. doi: 10.1016/s0003-4975(02)04154-1.

Abstract

Background: Monitoring motor-evoked potentials (MEPs) is an accurate technique to assess spinal cord integrity during thoracoabdominal aortic aneurysm (TAAA) repair, guiding surgical strategies to prevent paraplegia.

Methods: In 210 consecutive patients with type I (n = 75), type II (n = 103), and type III (n = 32) TAAA surgical repair was performed using left heart bypass, cerebrospinal fluid drainage, and MEPs monitoring.

Results: Reliable MEPs were registered in all patients. The median total number of patent intercostal and lumbar arteries was five. After proximal aortic crossclamping, MEP decreased below 25% of base line in 72 patients (34%) indicating critical spinal cord ischemia, which could be corrected by increasing distal aortic pressure. By using sequential clamping it appeared that in 43% of type I and II cases spinal cord circulation was supplied between T5 and L1, and 57% between L1 and L5. In type II and III cases cord perfusion was dependent upon lower lumbar arteries in 16% and pelvic circulation in 8%, necessitating reattachment of these segmental arteries. In 9% of patients critical ischemic MEP changes occurred without visible arteries, requiring aortic endarterectomy and selective grafting. One patient suffered early paraplegia and 2 delayed, and 2 patients had temporary neurologic deficit (5 of 210; 2.4%).

Conclusions: In patients with TAAA, blood supply to the spinal cord depends upon a highly variable collateral system. Monitoring MEPs is an accurate technique for detecting cord ischemia, guiding surgical tactics to reduce neurologic deficit (2.4%).

MeSH terms

  • Adult
  • Aged
  • Aneurysm, Dissecting / mortality
  • Aneurysm, Dissecting / surgery*
  • Aortic Aneurysm, Abdominal / mortality
  • Aortic Aneurysm, Abdominal / surgery*
  • Aortic Aneurysm, Thoracic / mortality
  • Aortic Aneurysm, Thoracic / surgery*
  • Collateral Circulation / physiology
  • Evoked Potentials, Motor / physiology
  • Female
  • Hospital Mortality
  • Humans
  • Intraoperative Complications / physiopathology
  • Intraoperative Complications / prevention & control*
  • Male
  • Middle Aged
  • Monitoring, Intraoperative*
  • Neurologic Examination
  • Prognosis
  • Reproducibility of Results
  • Spinal Cord Ischemia / physiopathology
  • Spinal Cord Ischemia / prevention & control*