Fighting spinal cord complication during surgery for thoracoabdominal aortic disease

Abstract

Paraplegia or paraparesis after otherwise successful thoracic or thoracoabdominal aortic reconstruction is a devastating complication for both patient and physician. Various strategies have been developed to minimize the incidence of neurological complications after aortic surgery. The incidence of spinal cord ischemia and subsequent neurological complications has been correlated with (1) the duration and severity of ischemia, (2) failure to establish a spinal cord blood supply, and (3) reperfusion injury. Preoperative identification of the arteria radicularis magna, the artery of Adamkiewicz, facilitates identification of critical intercostal vessels for reimplantation, resulting in reestablishing spinal cord blood flow. Techniques for monitoring spinal cord function using evoked potentials have been developed, and surgical techniques have evolved to reduce the duration of ischemia. Furthermore, sequentially sacrificing all the intercostal arteries while maintaining collateral circulation to the cord has produced good outcomes. The severity of ischemia can be minimized by using cerebrospinal fluid drainage, hypothermia, distal bypass, managing the blood pressure, and adjunctive pharmacological therapy. Reperfusion injury can be reduced with the use of antioxidant therapy. Recent advances in endovascular stentgrafting have reduced the incidence of postoperative spinal complications, especially among high-risk patients.

Current and emerging treatment options for spinal cord ischemia

“…These are (i) immediate paraplegia, which is mediated by ischemia; and (ii) delayed paraplegia, which is the consequence of inflammation. Postoperative paraplegia occurs more frequently in patients with a Crawford type II extension aneurysm, older age, and renal dysfunction [27]. Further risk factors for SCI include extensive aortic repair, prior aortic repair, left subclavian coverage, spinal cord malperfusion on clinical presentation, systemic hypotension, acute anemia, prolonged aortic clamping, and vascular steal [28].…”

Role of Induced Hypothermia in Thoracoabdominal Aortic Aneurysm Surgery

“…Hypothermia causes coagulopathy through reversible platelet dysfunction, enhanced fibrinolytic activity, and slow enzymatic activity required for clotting (Rohrer and Natale, 1992). Moreover, using CPB for induced hypothermia requires full heparinization, which increases the risk of bleeding along with the coagulopathy caused by hypothermia (Okita, 2011). In addition, an increase in the incidence of infection at wound sites has been reported with systemic hypothermia application (Beltramini et al, 2011).…”

Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion

“…The injury, known as spinal cord ischemia-reperfusion injury (SCIR), results in paralysis in up to 20% of high risk patients 1 . Surgical adjuncts such as left heart bypass, lumbar cerbrospinal fluid drains, hypothermic circulatory arrest and intercostal artery reimplantation have reduced the incidence of this complication 2 ; however, far too many patients continue to be affected.…”