| Anterior communicating artery aneurysm (anterior communicating aneurysms, AComA) accounts for approximate 30% all intracranial aneurysms, with high mortality and morbidity rate., so anatomical study of the anterior communicating artery complex is of important clinical value. Anterior communicating artery complex is muti-artery which circle anterior communicating artery, together with the adjacent Al and A2, and even to including Heubner’s recurrent artery, which is also called the anterior cerebral artery-anterior communicating-the recurrent artery complex by some scholars. The aim of this study is to explore the anatomy of the anterior communicating artery complex through the three dimensional reconstruction of DSA, which may be helpful to decide the treatment modality, surgical approach, identification and protection of neighboring vessels.AbstractThe anatomical study of three-dimensional reconstruction of the anterior communicating artery complex provides guidance in the surgical clipping or coiling of anterior communicating artery aneurysms, reduces complications and mortality, improves outcome.Materials and Methods30 patients were admitted into the department of neurosurgery, wuhan general hospital of Guangzhou command, from October 2010 to May 2011, including 21 males and 9 females, who presented with spontaneous subarachnoid hemorrhage in 27 cases, cerebral infarction, traumatic epistaxis and spontaneous parietal cerebral hemorrhage in lcase, respectively.Bilateral internal carotid arteries and vertebral arteries angiography were completed via right femoral artery approach, using Seldinger technique on GE the Innova 3100.The image of skull and soft tissue was subtracted and anteroposterio and lateral image of the cerebral vascular image acquired. The three dimension image was acquired after post processing routinely. Routinely, the contrast is infected into internal carotid artery at 9ml/s, and vertebral artery at 7ml/s.3D-DSA is accepted to be the gold standard for diagnosis of intracranial aneurysm. The high-resolution 3D-DSA could display a cerebral blood vessel in diameter of 0.3mm. Three-dimensional imaging enable us view the target at any angles, without the influence vascular angulations and overlapping All cerebral angiography were negative, with age ranging from 36 to77 years old, and mean age is 53 years old.3D reconstruction were processed on GEAW workstation (AW4.3 version) in which, the anterior communicating artery complex was enlarged to satisfactory extent, the diameter of proximal and distal of A1 segment, the length of A1 segment, the diameter of the proximal of A2, the angle formatted by Al and the internal carotid artery; angle formatted by Al and A2. The diameter of the recurrent artery diameter (the reservation decimally hind two.). Variety of morphological variation of the blood vessels was recorded as picture or drawing. Data was recorded as mean_standard deviation (x ± s) and t-test, was used to determine the difference. P<0.05 was considered significant All analyses were performed using SPSS13.0 for Windows (SPSS, Inc., Chicago, IL).ResultDeletion of the left anterior cerebral artery and right anterior cerebral artery in 1 case (3.3%), respectively, left advantageous blood supply in four cases (13.3%) and right advantageous blood supply in three cases (10%), balanced blood supply in 21 cases (70%).In two cases of 30 patients, the Al segment were missed Diameter of the right A1 at starting point was 2.04 ± 0.39mm, and 1.79 ± 0.45 mm at final point, the right side of the Al average of 1.91 ± 0.36 mm, the length of right Al wasl3.0 ± 1.60mm,.Diameter of the left Al at starting point was 1.97 ± 0.42mm, and 1.65 ± 0.35 mm at final point.the left Al mean of 1.81 ±0.36 mm, the left side of the length of left Al length was14.0 ± 2.28mm Diameter of the right A2 and right recurrent artery was 1.88±0.38 mm,0.50±0.15 mm, respectively. Diameter of the left A2 and right recurrent artery was 1.69±0.36 mm,0.42±0.13 mm, respectively. Angle formatted by right Al and A2 was 94.13±23.59±; Angle formatted by right Al and ICA was 89.14±16.61°;Angle formatted by left Al and A2 was 97.74±25.19°; Angle formatted by left Al and ICA was 82.30±21.06±;T test was used and no significant difference was found in bilateral diameter of A1 (t=0.612,p=0.28,), Al length (t=-0.289,p=0.774), angels formatted by Al and A2 (p=0.58) and angle formatted by A1 and ICA (p=0.18)ConclusionAnterior communicating artery complex varies much anatomically in its shape, diameter, length, and even the number of branches. This study found that A1 variation included uneven development, stunted growth, and deletion. Absence of anterior cerebral artery absence was found in two cases (6.6%), dominant blood supply in seven cases (23.3%), stunted growth,Al in 9 cases (30%),which consistent with the previous anatomic results. Relevant factors of the anterior communicating artery aneurysms include:1. Shear stress.a blood flow impact on vascular shear stress and pressure can cause damage of internal elastic lamina in the bifurcation of the intracranial arteries and middle layer defects by the continuous impact of blood flow, then swelling locally, and ultimately an aneurysm.2. Inconsistency of bilateral A1 also contributed to the anterior communicating artery aneurysm. Non-dominant side A1 segment diameter is gradually decreased; at the dominant side, wall shear stress on A1 segment near the anterior communicating artery increases. The wall shear stress may play a major role in the anterior communicating artery aneurysm.3. Arterial diseases also relevant to aneurysms, such as congenital muscular fibrous dysplasia, congenital connective tissue disease such as:Marfan’ syndrome, autosomal dominant polycystic kidney, osteogenesis imperfecta type -I. Others may include hypertension, diabetes, smoking, high cholesterol, infection and so on. Compared with traditional anatomical study of corpse, we have found no significant difference in bilateral A1 and A2 diameter.3D-DSA also has it advantages:firstly, its data is derived from living body; secondly, space structure is not displaced. In surgery or autopsy, lateral cistern, ICA cistern and suprachiasmatic cistern will be opened and cause brain tissue shift, so 3D-DSA has more the position accuracy than surgery or autopsy. Thirdly, large sample size, the source of the corpse head is limited. Fourth, the software facilitates the measurement of length or angel. It is difficulty to make measurement in limited space, meanwhile, it also makes mistake even increase the error, and in the process of anatomy of small penetrating branch may be injured. Finally, Data of 3D-DSA can be saved and achievable at any time. The lack of 3D-DSA is that it can only show vascular structure but can not display the spatial relationships of vessel and the surrounding tissue. And this may be compensated by the CTA.3D-DSA can only display a large penetrating branch such as the recurrent artery, orbitofrontal artery, other smaller artery such as penetrating branch of hypothalamus can not display for the flowing reasons:It does not develop, or subtracted in the process of three-dimensional reconstruction. If the aim is small penetrating branch, the corpse head anatomy may be superior to 3D-DSA The complexity of the microscopic anatomy of the anterior communicating artery complex, make AcomA the most difficult aneurysm of the anterior circulation. Treatment of AcomA includes surgical clipping and endovascular embolization. Which kind of treatment should be chosen depends on aneurysm size, aneurysm shape and so on. Another factor should be taken account of is the mastery of the two treatment modalities. On surgical plan, the 3D-DSA can help operator to decide approach according to the orientation of the aneurysm, the dominant blood flow and vascular overlapping to the aneurysm. For wide neck anterior communicating artery aneurysm,3D-DSA is also helpful to choose appropriate stent without affecting the patency of the anterior communicating artery, according to diameter and angel of Al andA2. The surgery of anterior communicating artery aneurysm needs wealthy surgical experience and microsurgical techniques. in the surgery of AcomA, the control of proximal artery is very important, routinely, surgeons usually select the dominant blood supply side to clipping of the anterior communicating artery aneurysm. Professor Li Jun firstly proposed the non-dominant blood supply side pterional approach clipping of anterior communicating artery aneurysm. Professor Li Jun firstly simulate the pterional approach on 3D-DSA, then select a proper side that the aneurysm and the anterior communicating artery complex were exposed most clearly, and he has got good outcome too. Compared with conventional MRA and CTA, DSA has its shortcoming. It is an invasive procedure and associated with complications. Complications may include:embolism caused by intravascular plaque and thrombosis, this may cause cerebral infarction, resulting in hemiplegia, aphasia, coma, vegetative state even death. Complications associated with femoral artery puncture include the subcutaneous and retroperitoneal hematoma, dissecting aneurysm and so on. Rarer, complications includes catheter distortion, even broken catheter for vascular tortuosity. Therefore, in the procedure of cerebral angiography, to minimize complications the action should be gentle。... |
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