Prevalence of Microanatomic Variants of the Anterior Cerebral Artery

Prevalence of Microanatomic Variants of the Anterior
Cerebral Artery-Anterior Communicating Artery Complex
in patients of the Hospital Universitario "Dr. José Eleuterio
González" in Monterrey, Mexico.
Poster No.:
C-0987
Congress:
ECR 2016
Type:
Educational Exhibit
Authors:
R. A. Cuéllar Lozano , R. Pinales Razo , J. R. CANTU
1
1 1
2
2
GONZALEZ ; Monterrey, Nu/MX, Monterrey, N.L./MX
Keywords:
Aneurysms, Statistics, Normal variants, Image manipulation /
Reconstruction, CT-Angiography, Vascular, Neuroradiology brain,
Anatomy
DOI:
10.1594/ecr2016/C-0987
Any information contained in this pdf file is automatically generated from digital material
submitted to EPOS by third parties in the form of scientific presentations. References
to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in
any way constitute or imply ECR's endorsement, sponsorship or recommendation of the
third party, information, product or service. ECR is not responsible for the content of
these pages and does not make any representations regarding the content or accuracy
of material in this file.
As per copyright regulations, any unauthorised use of the material or parts thereof as
well as commercial reproduction or multiple distribution by any traditional or electronically
based reproduction/publication method ist strictly prohibited.
You agree to defend, indemnify, and hold ECR harmless from and against any and all
claims, damages, costs, and expenses, including attorneys' fees, arising from or related
to your use of these pages.
Please note: Links to movies, ppt slideshows and any other multimedia files are not
available in the pdf version of presentations.
Page 1 of 20
www.myESR.org
Page 2 of 20
Learning objectives
•
To understand the normal anatomy and the microanatomic variants of the
Anterior Cerebral Artery-Anterior Communicating Artery Complex.
•
To know the prevalency of the microanatomic variants of the Anterior
Cerebral Artery-Anterior Communicating Artery Complex in patients of the
Hospital Universitario "Dr. José Eleuterio González" in Monterrey, Mexico.
•
To validate the brain angio CT scan as a top image study for the diagnose of
microanatomic vascular variants.
Background
INTRODUCTION
Cerebral circulation origins with the carotid arteries, the left carotid artery rises stright
from the aortic arch branch and the right carotid rises from the arterial brachiocephalic
trunk. The anterior cerebral arterial circulation is formed by both internal carotid arteries.
The internal carotid arteries have an intracraneal division, creating the anterior cerebral
artery and middle cerebral artery (Fig. 1).
Page 3 of 20
Fig. 1: Anterior Cerebral Circulation
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
The first horizontal segment of the anterior cerebral artery (ACA) is called A1, the medial
lenticulostriate arteries arise from this segment as well as the anterior communicating
artery (AComA) which irrigates the caudate nucleus and the anterior limb of the internal
capsule. The A2 segment extends from the AComA to the bifurcation forming the
callosomarginal and pericallosal arteries (A3).
CLINICAL RELEVANCE
The ACA-AComA complex is the most common site for intracraneal aneurysms and, even
then, the anatomic variants in Mexican population are not properly described in current
literature.
An aneurysm is the result of weakness in the artery wall layers, wich is seen as a focal
dilatation of the affected artery with risk of rupture and resultant hemorragic stroke. The
most common type of aneurysm in the central nervous system is the saccular (Fig. 2).
The rupture of an aneurysm is the most common non-traumatic source of subarachnoid
hemorrhage and it's cause of an significant porcentage of morbility and mortality.
Fig. 2: Types of Cerebral Aneurysms
Page 4 of 20
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
Images for this section:
Fig. 1: Anterior Cerebral Circulation
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 5 of 20
Fig. 2: Types of Cerebral Aneurysms
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 6 of 20
Findings and procedure details
MATERIALS AND PROCEDURE DETAILS
Type of study: retrospective, observational and descriptive.
The selection of individuals took place in a 22 month period (March 2014 - December
2015) and was formed by 283 patients with a angio CT scan at the Radiology Department
on the Hospital Universitario, José Eleuterio Gonzalez in Monterrey, Nuevo León, México.
The angio CT scan in these individuals were performed for many different pathologies
(trauma, cephalea, probable hemorrages or vascular pathologies and neoplasms). The
inclusion criteria were angio CT scan performed with intravenous contrast material
and study adquisition with at least 0.25mm slices. Exclusion criteria were history of
intracraneal surgery for of alteration of normal anatomy, aneurysm clipping or coiling
because of metallic artifact. This investigation protocol was approved by the Bioethic Staff
of the Faculty of Medicine of the Universidad Autonoma de Nuevo Leon (UANL) with the
registration code AH14-00.
ADQUISITION AND IMAGE ANALISIS
The images were adquired by a 64 slices CT Scanner (General Electric CT99 Light Speed
VCT, software 2978195VCT) with an helicoidal rotation adquisition of 0.4s, detectors
of 20mm, 120 Kv, mAs 400, slice thickness of 0.625mm, pitch 0.53:1mm/rot, FOV of
22-33cm.
All patients were administered with intravenous iodinated contrast (Ultravist 370, Bayer,
Germany) with a dose of 2 ml/kg, with a speed of injection of 4 ml/sec.
The data obtained was transferred and analyzed with a Work Station AW Volumen
Share2 using multiplanar reconstruction (MPR) with maximum intensity projection (MIP)
and volume rendering (VR).
All images were analyzed by a third year resident of the Radiology residency program of
and a neurorradiology professor at the Hospital Universitario, José Eleuterio Gonzalez
Page 7 of 20
It was determinated as a hypoplasic segment any artery with an internal diameter under
1mm.
The microanatomical variants were arranged by the Ozaki classification:
1. Fenestration of the Anterior Communicating Artery.
•
•
•
•
•
•
•
"V" Shape.
"Y"" Shape.
"H" Shape.
"N" Shape.
Double.
Triple.
Plexiform.
2. "X" Shape.
3. Asymmetry of A1.
•
•
•
Abscence.
Hypoplasia
Fenestration.
4. Asymmetry of A2.
•
•
•
•
•
Abscence.
Hypoplasia.
Fenestration.
Accesory (Triple A2).
Azygos.
Page 8 of 20
Fig. 3: Ozaki's Classification
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
FINDINGS
Page 9 of 20
The study group consisted of 283 individuals, from which 270 (95%) were adults and 13
(5%) were pediatrics; 156 (55.1 %) were males and 127 (44.9%) were females.
The most common variant found was the abscence of AcomA (14.1%), being more
frequent in the male population (52.2% vs 47.5%; p= 0.620).
The most common variant of the A1 segment was the abscence of the A1 segment (16
cases, 5.65%), being more frequent on the left segment (9 cases, 3.2%).
Fig. 5: Abscence of left A1
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
Microanatomical Variants of A1
Number of Cases
Porcentage %
No Variants
246
86.92
Abscence
16
5.65
Hypoplasia
15
5.3
Fenestration
6
2.12
TOTAL
283
100
The second most common variant found in the AcomA after the abscence was the "X"
shape (9 cases, 3.2%), from which 6 were males (66.7%) and 3 were females (33.3%).
Only one case was found for double and triple AcomA (0.4%).
Page 10 of 20
Fig. 6: AcomA "X" Shape
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
Microanatomical Variants of AcomA
Number of Cases
Porcentage %
No Variants
232
82
"X" Shape
9
3.2
Double
1
4
Triple
1
4
Abscence
40
14.1
TOTAL
283
100
The most common variant of the A2 segment was the hypoplasia found in 12 individuals
(4.24%), present in equal proportion 6 cases for right sided variant and 6 cases for left
sided variant hypoplasia.
The variant of the single A2 segment (azygos) was found in 5 individuals (1.8%).
Page 11 of 20
Fig. 7: Hypoplasia + Azygos Variant
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
Accesory ACA (triple A2) was found in 11 individuals (3.9%).
Fig. 8: Triple A2
References: Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr.
José Eleuterio González - Monterrey/MX
Page 12 of 20
Images for this section:
Fig. 3: Ozaki's Classification
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 13 of 20
Fig. 4: Abscence of ACOM
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Fig. 5: Abscence of left A1
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 14 of 20
Fig. 6: AcomA "X" Shape
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Fig. 7: Hypoplasia + Azygos Variant
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 15 of 20
Fig. 8: Triple A2
© Centro Universitario de Imagen Diagnóstica, hospital Universitario Dr. José Eleuterio
González - Monterrey/MX
Page 16 of 20
Conclusion
CONCLUSION
Microanatomical variants were found in 41.4% of the individuals, this porcentage is
different than was found in the international population (some higher than 80%).
The most common variant found in our population is the abscence of AcomA without
relation to gender.
Prevalency porcentage in our population of the A1 segment does not match the
international literature.
The prevalency of the azygos variant is 1.8%, this agrees with international literature and
post mortem studies performed in our country that report prevalency between 0.3- 2%.
The angio CT scan is a reliable method to analyze the microanatomic variants of the
anterior cerebral complex and our results are consistent with the reportes in post mortem
studies by Monroy Sosa in our country.
Personal information
Rolando Alberto Cuéllar Lozano
Resident of 4th year of Radiology, Departament of Radiology, Faculty of Medicine,
Hospital Universitario "Dr. Jose Eleuterio Gonzalez", Universidad Autonoma de Nuevo
Leon (UANL), Mexico.
[email protected]
Ricardo Pinales Razo
Proffesor of neurorradiology, Departament of Radiology, Faculty of Medicine, Hospital
Universitario "Dr. Jose Eleuterio Gonzalez", Universidad Autonoma de Nuevo Leon
(UANL), Mexico.
[email protected]
Page 17 of 20
Juan Ramón Cantú González
Interventional radiologist, Departament of Radiology, Faculty of Medicine, Hospital
Universitario "Dr. Jose Eleuterio Gonzalez", Universidad Autonoma de Nuevo Leon
(UANL), Mexico.
[email protected]
References
1. GrzegorzMakowicz, Renata Poniatowska, and Ma#gorzata Lusawa.
Variants of cerebral arteries - anterior circulation. Pol J Radiol. 2013 JulSep; 78(3): 42-47.
2. David M. Yousem, MD, MBA, Robert D. Zimmerman, MD and Robert I.
Grossman, MD. Neuroradiology: The Requisites, 3rd Edition.
3. Krzy#ewski RM, Tomaszewski KA, Kochana M, Kope# M, KlimekPiotrowska W, Walocha JA. Anatomical variations of the anterior
communicating artery complex: gender relationship. Surg Radiol
Anat. 2015 Jan;37(1):81-6. doi: 10.1007/s00276-014-1313-7.
4. Ciurea AV, Palade C, Voinescu D, Nica DA. Subarachnoid hemorrhage
and cerebral vasospasm - Literature review. J Med Life. 2013; 6 (2):12025.
5. Dr. Justo L. González González, Dr. Humberto Hernández Zayas,Dr.
Roberto Verdial Vidal. Aneurismas del complejo arteria cerebral
anterior / arteria comunicante anterior. Resultados del tratamiento
quirúrgico. Rev Cubana Cir v.45 n.1 Ciudad de la Habana ene.mar. 2006
Page 18 of 20
6. Hernesniemi J1, Dashti R, Lehecka M, Niemelä M, Rinne J, Lehto
H, Ronkainen A, Koivisto T, Jääskeläinen JE. Microneurosurgical
management of anterior communicating artery aneurysms. Surg
Neurol. 2008 Jul;70(1):8- 28; discussion 29. doi: 10.1016/j.surneu.2008.01.056. Epub
2008 May 2.
7. Monroy Sosa, Pérez, Reyes, Delgado, Macias. Importancia de la
anatomía microquirúrgica del complejo A1-arteria comunicante anterior.
Cirugía y cirujanos (Impact Factor: 0.32). 07/2013; 81:274-281.
8. Zhang QR, Zhang X, Wu Q, Shi JX, Wang HD, Hang CH, Cheng HL, Liu
JM. The impact of microsurgical clipping and endovascular coiling on the
outcome of cerebral aneurysms in patients over 60 years of age. J Clin.
Neurosci. 2012 Aug;19(8):1115-8. doi: 10.1016/j.jocn.2011.11.017. Epub
22
9. Omar Choudhri,1 Nitin Mukerji,1 and Gary K. Steinberg. Combined
Endovascular and Microsurgical Management of Complex Cerebral
Aneurysms. Front Neurol. 2013; 4: 108. Published online 2013 Aug 8
10. Simon J. Dimmick, BPthy, MBBS • Kenneth C. Faulder. Normal Variants
of the Cerebral Circulation at Multidetector CT Angiography
RadioGraphics 2009; 29:1027-1043 Published online
10.1148/rg.294085730
11. Auguste KI, Ware ML, Lawton MT.
Nonsaccular aneurysms of the azygos anterior cerebral artery.
Neurosurg Focus. 2004 Nov 15;17(5):E12.
Page 19 of 20
Page 20 of 20