1. Chapter 2 Neurologic Complications of Aortic Disease and Surgery
Douglas S. Goodin
Copyright © 2014 Elsevier Inc. All rights reserved.

2. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-1 Extraspinal contributions to the anterior spinal arteries showing the three arterial territories. In the cervical region, an average of three arteries (derived from the vertebral arteries and the costocervical trunk) supply the anterior spinal artery. The anterior spinal artery is narrowest in the midthoracic region, often being difficult to distinguish from other small arteries on the anterior surface of the cord; occasionally it is discontinuous with the anterior spinal artery above and below. In addition, this region is often supplied by only a single small radiculomedullary vessel. The lumbosacral territory is supplied by a single large artery, the great anterior medullary artery of Adamkiewicz, which turns abruptly caudal after joining the anterior spinal artery. If it gives off an ascending branch, that branch is usually a much smaller vessel. This artery is usually the most caudal of the anterior radiculomedullary arteries, but when it follows a relatively high thoracic root, there is often a small lumbar radiculomedullary artery below. In this and subsequent illustrations, a indicates artery; m, muscle; n, nerve.
Copyright © 2014 Elsevier Inc. All rights reserved.

3. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-2 Anatomy of the spinal cord circulation, showing the relationship of the segmental arteries and their branches to the spinal canal and cord. The left rib and the left pedicle of the vertebra have been cut away to show the underlying vascular and neural structures.
Copyright © 2014 Elsevier Inc. All rights reserved.

4. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-3 Vascular anatomy of the spinal cord. The anterior spinal artery gives off both peripheral and sulcal branches. The sulcal branches pass posteriorly, penetrating the anterior longitudinal fissure. On reaching the anterior white commissure, they turn alternately to the right and to the left to supply the gray matter and deep white matter on each side. Occasionally two adjacent vessels pass to the same side, and on other occasions, a common stem vessel bifurcates to supply both sides. Terminal branches of these vessels overlap those from vessels above and below on the same side of the cord. The peripheral branches of the anterior spinal artery pass radially and form an anastomotic network of vessels, the anterior pial arterial plexus, which supplies the anterior and lateral white matter tracts by penetrating branches. The posterior pial arterial plexus is formed as a rich anastomotic network from the paired posterior spinal arteries. Penetrating branches from this plexus supply the posterior horns and posterior funiculi.
Copyright © 2014 Elsevier Inc. All rights reserved.

5. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-4 Intrinsic blood supply of the spinal cord. The vascular territories are depicted on one side of the cord. The territory supplied by the posterior spinal arterial system is indicated. The remainder is supplied by the anterior circulation, with the darker region indicating the area supplied exclusively by the sulcal branches of the anterior spinal artery.
Copyright © 2014 Elsevier Inc. All rights reserved.

6. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-5 Upper segmental level of spinal cord involvement in 61 cases of spinal cord ischemia after surgery on the aorta (based on previously published reports).
Copyright © 2014 Elsevier Inc. All rights reserved.

7. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-6 Area of infarction within the spinal cord over four adjacent spinal segments in a patient reported by Herrick and Mills (Herrick MK, Mills PE: Infarction of spinal cord. Two cases of selective gray matter involvement secondary to asymptomatic aortic disease. Arch Neurol 24:228, 1971). The infarction was extensive but limited to the gray matter, particularly the anterior horns.
Copyright © 2014 Elsevier Inc. All rights reserved.

8. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-7 Vascular anatomy of the aortic arch and its branches.
Copyright © 2014 Elsevier Inc. All rights reserved.

9. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-8 Mechanisms producing subclavian steal syndrome in diseases of the aortic arch and its branches. A, Obstruction of the left subclavian artery at its origin, resulting in reversal of blood flow in the left vertebral artery. B, Obstruction of the right subclavian artery distal to the takeoff of the right common carotid artery, resulting in reversal of blood flow in the right vertebral artery. C, Obstruction of the innominate artery at its origin, producing reversal of blood flow in the right common carotid artery.
Copyright © 2014 Elsevier Inc. All rights reserved.

10. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-9 Anatomy of the abdominal aorta showing its relationship to the femoral and obturator nerves, which form within the psoas muscle from branches of the L2, L3, and L4 segmental nerves.
Copyright © 2014 Elsevier Inc. All rights reserved.

11. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-10 Anatomy of the terminal branches of the aorta in relationship to the nerve roots that subsequently join to form the sciatic nerve. Aneurysmal dilatation of the abdominal aorta often includes dilatation of these branch vessels, which can compress the nerve roots, particularly the L4, L5, S1, and S2 nerve roots, which lie directly underneath.
Copyright © 2014 Elsevier Inc. All rights reserved.

12. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-11 Anatomy of the terminal aorta and pelvis in the male in relationship to the sympathetic and parasympathetic nerves in the region.
Copyright © 2014 Elsevier Inc. All rights reserved.

13. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-12 Distribution of sympathetic (left) and parasympathetic (right) nerves to the pelvic viscera and sexual organs in the male.
Copyright © 2014 Elsevier Inc. All rights reserved.

14. Copyright © 2014 Elsevier Inc. All rights reserved.
Figure 2-13 Mechanism of steal in coarctation of the aorta. Obstruction of the aorta at the isthmus causes dilatation of the anterior spinal artery and reversal of blood flow in anterior radiculomedullary arteries distal to the obstruction. In this circumstance, the blood flow to the lower extremities is provided by these (and other) collaterals, and use of the lower extremities may cause shunting of blood from the spinal circulation to the legs, which, in turn, sometimes results in spinal cord ischemia.
Copyright © 2014 Elsevier Inc. All rights reserved.