Microsurgical anatomy of the arterial basket of the conus medullaris

Authors

Nikolay L. Martirosyan, Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix; and.Follow
M Yashar Kalani, Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix; and.Follow
G Michael Lemole, Division of Neurological Surgery, University of Arizona, Tucson, Arizona.
Robert F. Spetzler, Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix; and.
Mark C. Preul, Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix; and.
Nicholas Theodore, Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix; and.

Document Type

Article

Abstract

OBJECT The arterial basket of the conus medullaris (ABCM) consists of 1 or 2 arteries arising from the anterior spinal artery (ASA) and circumferentially connecting the ASA and the posterior spinal arteries (PSAs). The arterial basket can be involved in arteriovenous fistulas and arteriovenous malformations of the conus. In this article, the authors describe the microsurgical anatomy of the ABCM with emphasis on its morphometric parameters and important role in the intrinsic blood supply of the conus medullaris. METHODS The authors performed microsurgical dissections on 16 formalin-fixed human spinal cords harvested within 24 hours of death. The course, diameter, and branching angles of the arteries comprising the ABCM were then identified and measured. In addition, histological sections were obtained to identify perforating vessels arising from the ABCM. RESULTS The ASA tapers as it nears the conus medullaris (mean preconus diameter 0.7 ± 0.12 mm vs mean conus diameter 0.38 ± 0.08 mm). The ASA forms an anastomotic basket with the posterior spinal artery (PSA) via anastomotic branches. In most of the specimens (n= 13, 81.3%), bilateral arteries formed connections between the ASA and PSA. However, in the remaining specimens (n= 3, 18.7%), a unilateral right-sided anastomotic artery was identified. The mean diameter of the right ABCM branch was 0.49 ± 0.13 mm, and the mean diameter of the left branch was 0.53 ± 0.14 mm. The mean branching angles of the arteries forming the anastomotic basket were 95.9° ± 36.6° and 90° ± 34.3° for the right- and left-sided arteries, respectively. In cases of bilateral arterial anastomoses between the ASA and PSA, the mean distance between the origins of the arteries was 4.5 ± 3.3 mm. Histological analysis revealed numerous perforating vessels supplying tissue of the conus medullaris. CONCLUSIONS The ABCM is a critical anastomotic connection between the ASA and PSA, which play an important role in the intrinsic blood supply of the conus medullaris. The ABCM provides an important compensatory function in the blood supply of the spinal cord. Its involvement in conus medullaris vascular malformations makes it a critical anatomical structure.

Medical Subject Headings

Arteries (anatomy & histology); Arteriovenous Malformations (pathology); Cadaver; Central Nervous System Vascular Malformations (pathology); Humans; Spinal Cord (anatomy & histology); Vascular Surgical Procedures

Publication Date

6-1-2015

Publication Title

Journal of neurosurgery. Spine

E-ISSN

1547-5646

Volume

22

Issue

6

First Page

672

Last Page

6

PubMed ID

25746117

Digital Object Identifier (DOI)

10.3171/2014.10.SPINE131081

Recommended Citation

Martirosyan, Nikolay L.; Kalani, M Yashar; Lemole, G Michael; Spetzler, Robert F.; Preul, Mark C.; and Theodore, Nicholas, "Microsurgical anatomy of the arterial basket of the conus medullaris" (2015). Neurosurgery. 1705.
https://scholar.barrowneuro.org/neurosurgery/1705