Microsurgical anatomy of the intracranial part of the vertebral artery

Abstract

We studied the intracranial portion of the vertebral artery and its branches in 11 cadaveric specimens. We evaluated the course of vessels and their dimensions (external diameter and length), as well as relationships between each of them. The vertebral artery was larger on the ? left side in two cases, on the right in five cases, and equal on both sides in four cases. The right and left vertebral arteries joined each other forming the basilar artery at the level of the pontomedullary junction in four cases, 2 mm below it in one case, and 1 to 7 mm above it in six cases. We divided all branches of the intracranial vertebral artery into two groups: the medial branches and the lateral branches. Two major types of medial branches were observed: the anterior spinal artery and the branches of the foramen caecum. The origin of the anterior spinal artery was located 6.5 mm (5-11 mm) proximal to vertebrobasilar junction on the right and 8.5 mm (6-17 mm) on the left. The anterior spinal artery was absent on the right in two cases and on the left in one. Branches arising from the vertebral artery to the foremen caecum were found in four brains. Lateral branches originated from the posterolateral or lateral aspect of vertebral artery. The posterior inferior cerebellar artery, the largest branch of the vertebral artery, was included in this group. Other branches were mostly located between the origin of the posterior inferior cerebellar artery and the vertebrobasilar junction. Forty-six lateral branches originating from the vertebral artery were found in 11 brains (26 on the right and 20 on the left). Lateral branches widely anastomosed with perforators from the basilar arteryposterior inferior cerebral artery; and the anterior inferior cerebellar artery. [Neurol Res 1994; 16:171–180]     

The perforating branches of the P1 segment of the posterior cerebral artery

The perforating branches of the P1 segment of the posterior cerebral artery are vulnerable to injury. Because of their close proximity to the basilar artery, the vulnerability occurs especially during surgical interventions for vascular pathologies such as basilar apex aneurysms. Therefore, extensive knowledge of the microsurgical anatomy of this area is mandatory to prevent poor post-operative outcomes. We microscopically examined 28 P1 segments obtained from 14 adult fresh cadaver brains (6 silicone injected, 8 freshly examined). The P1 segments ranged between 2.8 mm and 12.2 mm (mean 6.8 mm) in length with a mean outer diameter of 1.85 mm (range 0.8–4.5 mm). All 94 thalamoperforating branches identified in 27 P1 segments (mean 3.35 branches per segment) arose from the postero-superior aspect of P1 and were the most proximally originating branch in nearly all specimens (96.4%). In addition in 28 P1s, 12 short circumflex arteries (42.8%; mean 0.42 branches per segment), 16 long circumflex arteries (57.1%; mean 0.57 branches per segment) and 10 medial posterior choroidal arteries (35.7%; mean 0.35 branches per segment) were identified and all originated from the posterior or postero-inferior surface of the P1 segment. When the P1 segment had more than one type of branch, it was the short circumflex arteries that were always more proximal in origin than the others. The medial posterior choroidal arteries were always more distal in origin. All three branches were not observed together in any of the P1 segments. The findings in this, and future, anatomical studies may help to reduce the post-surgical morbidity and mortality rates after surgery for posterior circulation aneurysms.     

Anatomical basis for the lateral approach to the fourth ventricle

Abstract

This study focused on the posterior inferior cerebellar artery bifurcation and branching patterns in the fissures around the fourth ventricle. The vertebral arteries in 25 unfixed human cerebellum were cannulated and injected with polyester colored resin. The suboccipital surface of the cerebellum was exposed and the cisterna magna main landmarks localized. The average distance was 12.6 mm between the tonsillovermlan notches and 21.8 mm between the inferior tips of the tonsils. The mean vertical distance between these horizontal planes was 14.5 mm. The posterior inferior cerebellar artery was found in the cerebellomedullary fissure in 42 of 50 cerebellar hemispheres, in seven cases the artery was absent and in one it was hypoplastic. The mean outer diameter was 1.8 mm and the average length was 27.9 mm. The posterior inferior cerebellar artery presented four bifurcation point patterns: superomedial, superolateral, inferomedial, and inferolateral. These patterns were characterized into subtypes based on the courses of the vermian and tonsillohemispheric branches. The perforating and choroidal branches originating in these segments were also studied. The mean number of perforating branches per hemisphere was 5.1. The range of the length was 2-10 mm and the range of the outer diameter was 0.1-0.3 mm. An average of 4.6 choroidal arteries originated from the tonsillomedullary and telovelotonsillar segments, a mean of 4 arose from both vermian and tonsillohemispheric branches. This information will facilitate surgical planning in approaching the fourth ventricle as well as the interpretation of cerebellar infarcts in the posterior inferior cerebellar artery area. [Neurol Res 1999; 21: 444–456]     

臀上皮神经营养血管筋膜皮瓣移植的应用解剖特点

背景：臀上皮神经营养血管筋膜皮瓣是一类以皮神经血供为其成活基础的新型皮瓣，皮神经周围的营养血管在营养神经的同时发支营养其周围的筋膜皮肤。此皮瓣可以用最小的副损伤修复骶部压疮，并且皮瓣有感觉。 目的：拟通过对臀上皮神经筋膜皮瓣进行应用解剖学分析，为臀上皮神经筋膜移植皮瓣及其旋转点的精确设计提供解剖学依据。 设计、时间及地点：应用解剖学实验，于2006-03/05在大连医科大学解剖教研室及大连大学医学院解剖教研室完成。 对象：选取31侧用红色乳胶灌注、经甲醛固定的中国成人人体臀部标本。 方法：解剖成人人体臀部标本臀上动脉的肌皮穿支并测量其外径，解剖臀上皮神经和第4腰动脉后支观察其在深筋膜穿出点的位置，测量臀上皮神经中支的长度及第4腰动脉后支的外径。 主要观察指标：臀上皮神经筋膜移植皮瓣的解剖学数据。 结果：臀上皮神经中支长度（15.1±1.4）cm（n=31）。臀上皮神经中支支配区有效长度（13.3±1.5）cm（n=31）。臀上皮神经、第4腰动脉后支出肌点距髂嵴上缘距离（8.5±1.1）mm（n=31）。臀上皮神经、第4腰动脉后支出肌点距后正中线距离（7.1±1.6）cm（n=31）。第4腰动脉后支外径（1.0±0.3）mm（n=31）。臀上动脉上支的肌皮穿支外径：第1支（0.52±0.22）mm（n=15），第2支（0.42±0.18）mm（n=10）。 结论：臀上皮神经筋膜皮瓣的旋转点设计应距后正中线(7.1±1.6) cm，距髂嵴上缘(8.5±1.1) mm。臀上皮神经筋膜皮瓣宜以长度(13.3±1.5) cm，蒂部宽度3.5 cm为宜。     

Anatomical basis for the lateral approach to the fourth ventricle.

This study focused on the posterior inferior cerebellar artery bifurcation and branching patterns in the fissures around the fourth ventricle. The vertebral arteries in 25 unfixed human cerebellum were cannulated and injected with polyester colored resin. The suboccipital surface of the cerebellum was exposed and the cisterna magna main landmarks localized. The average distance was 12.6 mm between the tonsillovermian notches and 21.8 mm between the inferior tips of the tonsils. The mean vertical distance between these horizontal planes was 14.5 mm. The posterior inferior cerebellar artery was found in the cerebellomedullary fissure in 42 of 50 cerebellar hemispheres, in seven cases the artery was absent and in one it was hypoplastic. The mean outer diameter was 1.8 mm and the average length was 27.9 mm. The posterior inferior cerebellar artery presented four bifurcation point patterns: superomedial, superolateral, inferomedial, and inferolateral. These patterns were characterized into subtypes based on the courses of the vermian and tonsillohemispheric branches. The perforating and choroidal branches originating in these segments were also studied. The mean number of perforating branches per hemisphere was 5.1. The range of the length was 2-10 mm and the range of the outer diameter was 0.1-0.3 mm. An average of 4.6 choroidal arteries originated from the tonsillomedullary and telovelotonsillar segments, a mean of 4 arose from both vermian and tonsillohemispheric branches. This information will facilitate surgical planning in approaching the fourth ventricle as well as the interpretation of cerebellar infarcts in the posterior inferior cerebellar artery area.     

Microsurgical anatomy of the posterior circulation

CONTEXT: The microsurgical anatomy of the posterior circulation is very complex and variable. Surgical approaches to this area are considered risky due to the presence of the various important blood vessels and neural structures. AIMS: To document the microsurgical anatomy of the posterior circulation along with variations in the Indian population. MATERIALS AND METHODS: The authors studied 25 cadaveric brain specimens. Microsurgical dissection was carried out from the vertebral arteries to the basilar artery and its branches, the basilar artery bifurcation, posterior cerebral artery and its various branches. Measurements of the outer diameters of the vertebral artery, basilar artery and posterior cerebral artery and their lengths were taken. RESULTS: The mean diameter of the vertebral artery was 3.4 mm on the left and 2.9 mm on the right. The diameter of the basilar artery varied from 3-7 mm (mean of 4.3 mm). The length varied from 24-35 mm (mean of 24.9 mm). The basilar artery gave off paramedian and circumferential perforating arteries. The origin of the anterior inferior cerebellar artery (AICA) varied from 0-21 mm (mean 10.0 mm) from the vertebrobasilar junction. The diameter of the AICA varied from being hypoplastic i.e., CONCLUSIONS: The authors have documented the various anomalies as well as the differences of the anatomy in this area in the Indian population as compared to the Western literature.     

Anastomoses among the perforating arteries of the brain. Microanatomy and clinical significance

Anastomoses among the perforating arteries were examined in 50 human brains using injection technique with India ink and gelation, or methylmethacrylate. Anastomoses were not found among the perforators of the internal carotid artery and the thalamogeniculate branches. Anastomotic channels involving perforating branches of the anterior choroidal, middle cerebral, and anterior cerebral arteries were noted in 1% of the cases. Vascular connections of the premamillary arteries were observed in 30% of the brains. They varied from 60 to 280 microns) in diameter, and from 0.3 to 3.6 (mean 1.5 mm) in length. Anastomoses among the interpeduncular (thalamoperforating) branches of the posterior cerebral artery were present in 79% of the cases. They ranged from 80 to 400 microns (mean 146 microns) in caliber, and from 0.9 to 6.1 mm (mean 3.3 mm) in length. Since anastomoses among the interpeduncular and the premamillary arteries are much more frequent than those among other perforators, thalamic, subthalamic, and midbrain's infarctions seem to be less frequent than capsular and ganglionic ischemic lesions.     

国人髌骨假体设计参数的解剖学观测

目的：测量国人髌骨假体的解剖学参数。 方法：取成人干燥髌骨标本73块,左38块,右35块,测量髌骨假体骨床厚度,髌骨关节面厚度,髌骨外侧关节面宽度,髌骨内侧关节面宽度,髌骨内外侧关节面相交处长度,髌骨内外侧关节面的交角。实验结果用SPSS 10.0软件进行统计处理和分析。 结果：左右侧标本之间髌骨假体骨床厚度分别为(13.69±1.33),(13.35±1.19) mm;髌骨关节面厚度为(5.64±1.40),(5.63±1.26) mm;髌骨外侧关节面宽度为(24.54±2.27),(24.51±2.36) mm;髌骨内侧关节面宽度为(19.04±2.10),(18.54±1.81) mm;髌骨内外侧关节面相交处长度为(28.34±2.49),(27.44±2.20) mm;髌骨内外侧关节面的交角为(135.7±7.8)°,(136.5±7.6)°,各参数相比,差异均无显著性意义(P > 0.05)。 结论：实验中各参数可为国人髌骨骨床和截骨厚度的选择及髌骨假体设计参数提供参考。     

Anatomic and radiologic analysis of the atlantal part of the vertebral artery

The horizontal third segment (V3h) of the vertebral artery (VA) in 7 cadavers (14 sides) was dissected and the anatomical measurements recorded. Measurements from 24 healthy individuals (48 sides) were taken for comparison using multislice CT scanning. The distance between the medial tip of the VA V3h and the line passing through the mid point of the posterior tuberculum of the atlas was marked as length A. The distance between the medial tip of the VA V3h and the point penetrating the dura mater was classified as length B. The angle between these lines was the alpha (α) angle. Measurements were taken when the head was in a neutral position, as well as in maximum right and left rotation, extension and flexion. In cadavers, the mean α angle (±S.D.) was 82.42 ± 10.34° and 83.21 ± 10.81° on the right and left side, respectively. On multislice CT scanning, the mean α angle was 81.64 ± 10.15° on the right and 83.77 ± 10.65° on the left. These angles varied with the position of the head.     

经眼上静脉入路行海绵窦栓塞的应用解剖学

目的:为经眼上静脉入路行海绵窦栓塞术,治疗颈动脉-海绵窦瘘提供解剖学依据.方法:成人头部标本24个,解剖观测眼上静脉及其眶外属支的形态、长度及外径等.结果:①眼上静脉由眶上静脉支和内眦静脉交通支组成.眶上静脉支穿经眶上孔处外径为1.3mm.内眦静脉外径为1.4mm,距内眦6～8mm,其交通支外径为14mm.②眼上静脉在眶内分为3段,外径平均达2.1～2.5mm.结论:经眼上静脉及其属支入路可用于颈动脉-海绵窦瘘的血管内栓塞治疗     

C1 lateral mass screw insertion from the caudal–dorsal to the cranial–ventral direction as an alternate method for C1 fixation: A quantitative anatomical and morphometric evaluation

ObjectC1 lateral mass screw has been widely used for fixation of the upper cervical spine. However, traditional fixation methods are not without complication. Morphometric measurement of an alternative approach is conducted.MethodsThree-dimensional CT scans of the cervical spine obtained in 100 adults were evaluated, and key measurements were determined for screw entry points, trajectories, and screw lengths for placement of a C1 screw via this alternate approach. Additional measures were included to account for relevant anatomic variation, including the size of the dangerous lateral zone of the C1 entry point and depth of the atlantooccipital joint surface. Twenty dried atlantal specimens were evaluated to determine corresponding ex vivo measurements.ResultsThe mean maximum angle of medialization was 20.8° ± 2.8° (right) and 21.1° ± 2.8° (left), as measured in the axial CT images. Sagittal CT images show the mean maximum superior angulation was 24.7° ± 4.3° (right) and 24° ± 4.0° (left), and the mean minimum superior angulation was 13.6° ± 4.4° (right) and 13.6° ± 3.9° (left). The mean screw length within the lateral mass was 21.2 ± 1.9 mm (right) and 21.3 ± 2.0 mm (left). Given an additional 10–15 mm needed for rod adaptation, an ideal screw length of 30–35 mm was determined.ConclusionThe C1 insertion caudally from the C2 nerve root may become an alternate method. Preoperative consideration of the ideal screw insertion point, trajectory, and length are vital for safe and effective surgical intervention.     

Microsurgical anatomy of the lower basilar artery

Abstract

This study was designed to study the microvascular anatomy of the basilar artery between the superior cerebellar artery and the vertebrobasilar junction (i.e. the lower basilar artery). Twenty unfixed brains were injected with silicone rubber solution and studied with a Zeiss OPMI microscope. The length of this segment of the basilar artery was 28.1 + 1.35 mm and its course was straight in 9 (45%) brains, curved in 7 (35%) and tortuous in 4 (20%). The total number of perforators found in 20 brains was 340 with an average of 17 per brain. Of these, 118 (34.7%) were median and 222 ( 65.2%) were lateral. Median branches had a mean length of 5.8 + 1.25 mm, whereas left and right lateral branches had a mean length of 16 + 1.25 mm and 16 + 1.58 mm respectively.     

Deep perforators from the carotid system. Template of the vascular territories

Most reports on small infarcts in the territory of the deep perforators that arise from the internal carotid artery and its branches have focused on the anatomical structures. Recently, it has become possible to map the territories of the deep perforators from the carotid system, based on matching previous anatomical studies with recent data from computed tomographic and magnetic resonance imaging studies. The middle cerebral artery gives origin to two main groups of perforators: the medial and lateral lenticulostriate arteries. Rarely, the thalamotuberal artery may take origin from the middle cerebral artery but much more commonly it originates from the posterior communicating artery. The anterior cerebral artery gives origin to the anterior lenticulostriate arteries and the recurrent artery of Heubner. The anterior choroidal artery takes its origin from the internal carotid artery and exceptionally from the middle cerebral artery. In addition, a small group of perforators comes directly from the internal carotid artery. The anatomical structures supplied by these perforators are described, and a map of the territories is proposed.     

小脑浅静脉的显微解剖及临床意义

目的 观察小脑浅静脉的显微解剖结构.方法 利用20具(40侧)尸头标本,动、静脉分别用红蓝色乳胶灌注,在显微镜下观察小脑浅静脉的构成并测量相关的数据.结果 小脑浅静脉的构成中,15具标本的小脑中央前静脉纤细,外径平均为(1.1±0.14)mm;5具标本粗大,外径平均为(2.0±0.20)mm.20具标本(40侧)小脑前...     

Optic Nerve Sheath Diameter Detects Intracranial Hypertension in Acute Malignant Middle Cerebral Artery Infarction

ObjectivesTo evaluate optic nerve sheath diameter in the acute phase of patients with malignant ischemic middle cerebral artery stroke submitted or not to decompressive craniectomy surgery.Materials and MethodsForty patients participated in the study and were evaluated bilaterally by ultrasound on admission and at 24h, 48h and 72 h after admission. Optic nerve sheath diameter values were correlated with tomographic and/or clinical criteria compatible with severe intracranial hypertension.ResultsA Receiver Operating Characteristic curve was drawn for each eye, determining a cut-off value for severe intracranial hypertension in the right eye of 5.4 mm (sensitivity: 62%; specificity: 100%; AUC: 0.82) and in the left eye 5.4 mm (sensitivity: 76%; specificity: 84%; AUC: 0.77). In patients undergoing craniectomy, there was a decrease in the mean value of 1.04mm in the right eye (pre: 5.84 ± 0.47 mm; post: 4.80 ± 0.84 mm; p = 0.001), while in the left, it decreased around 0.86mm (pre: 5.59 ± 0.69 mm; post: 4.73 ± 0.74 mm; p = 0.003). Patients with fatal outcome showed a persistent high mean ocular nerve sheath diameter.ConclusionsMonitoring optic nerve sheath by ultrasound can be considered a reliable method for identifying severe intracranial hypertension in patients with large vessel occlusion, as well as for monitoring patients undergoing craniectomy. Additional studies will be necessary to include this parameter in craniectomy indication algorithms in the future.     

垂体上动脉显微外科解剖学研究

目的 了解垂体上动脉的起始、行程、分布和变异,为鞍区肿瘤手术时保护垂体上动脉以有变垂体上动脉瘤与床突旁其他类型动脉瘤区别提供依据。方法 ５０具成人尸体头颅垂体上动脉标本,在解剖显微镜下解剖和分析。结果 垂体上动脉为一组血管丛,分１～４支,起始于颈内动脉则,平均直径０．２２ｍｍ。起始部距眼动脉起始部小于５ｍｍ者占８２％,二种分支类型：粗大支型占４５％,呈烟台式供应垂体柄、视神经和视交叉,平均直径为０     

Anatomic and MRI Bases for Pontine Infarctions with Patients Presentation

ObjectivesThere are scarce data regarding pontine arteries anatomy, which is the basis for ischemic lesions following their occlusion. The aim of this study was to examine pontine vasculature and its relationships with the radiologic and neurologic features of pontine infarctions.Materials and methodsBranches of eight basilar arteries and their twigs, including the larger intrapontine branches, were microdissected following an injection of a 10% mixture of India ink and gelatin. Two additional brain stems were prepared for microscopic examination after being stained with luxol fast blue and cresyl violet. Finally, 30 patients with pontine infarctions underwent magnetic resonance imaging (MRI) in order to determine the position and size of the infarctions.ResultsThe perforating arteries, which averaged 5.8 in number and 0.39 mm in diameter, gave rise to paramedian and anteromedial branches, and also to anterolateral twigs (62.5%). The longer leptomeningeal and cerebellar arteries occasionally gave off perforating and anterolateral twigs, and either the lateral or posterior branches. Occlusion of some of these vessels resulted in the paramedian (30%), anterolateral (26.7%), lateral (20%), and combined infarctions (23.3%), which were most often isolated and unilateral, and rarely bilateral (10%). They were located in the lower pons (23.3%), middle (10%) or rostral (26.7%), or in two or three portions (40%). Each type of infarction usually produced characteristic neurologic signs. The clinical significance of the anatomic findings was discussed.ConclusionsThere was a good correlation between the intrapontine vascular territories, the position, size and shape of the infarctions, and the type of neurologic manifestations.     

Hemispheric asymmetries in blood flow during color stimulation

Abstract Visual stimulation influences mean blood flow velocities (MBFV) in posterior cerebral arteries (PCA). In 51 healthy, right-handed volunteers MBFV were measured in PCA with opened and closed eyes and while watching colored light (red, yellow, green, blue) for 1 minute. Volunteers had eyes closed 2 minutes between different colors. MBFV in left PCA was 41.2 ± 8.6 cm/s (mean ± 2SD) and 27.8 ± 8.5 cm/s with eyes opened and closed, respectively. For red light MBFV in left PCA was 31.4 ± 7.1 cm/s, for yellow 31.4 ± 7.2 cm/s, for green 32.0 ± 8.3 cm/s, and for blue 33.0 ± 7.6 cm/s. MBFV in right PCA 41.7 ± 8.9 cm/s and 28.2 ± 9.1 cm/s with eyes opened and closed, respectively. For red light MBFV in right PCA was 39.4 ± 8.4 cm/s, for yellow 38.9 ± 9.2 cm/s, for green 37.8 ± 9.4 cm/s and for blue 38.0 ± 8.8 cm/s. There was no significant difference in MBFV between left and right PCA with eyes opened and closed, but MBFV were significantly higher in right PCA for each color than corresponding MBFV in left PCA. These findings could indicate the greater metabolism of visual cortex in right occipital lobe while watching colors. Visual cortex of right occipital lobe could have greater importance in color perception than visual cortex of left occipital lobe.     

Arterial vascularization of the pineal gland

Purpose

The arterial vascularization of the pineal gland (PG) remains a debatable subject. This study aims to provide detailed information about the arterial vascularization of the PG.

Methods

Thirty adult human brains were obtained from routine autopsies. Cerebral arteries were separately cannulated and injected with colored latex. The dissections were carried out using a surgical microscope. The diameters of the branches supplying the PG at their origin and vascularization areas of the branches of the arteries were investigated.

Results

The main artery of the PG was the lateral pineal artery, and it originated from the posterior circulation. The other arteries included the medial pineal artery from the posterior circulation and the rostral pineal artery mainly from the anterior circulation. Posteromedial choroidal artery was an important artery that branched to the PG. The arterial supply to the PG was studied comprehensively considering the debate and inadequacy of previously published studies on this issue available in the literature.

Conclusions

This anatomical knowledge may be helpful for surgical treatment of pathologies of the PG, especially in children who develop more pathology in this region than adults.     

应用三丙烯微球对豚鼠子宫肌瘤模型行子宫动脉栓塞的实验

背景：子宫动脉栓塞术作为治疗子宫肌瘤的重要手段已广泛应用于临床,疗效令人满意,但对子宫动脉栓塞术的基础研究目前尚处于起步阶段,理论系统尚不完善。应用新型栓塞剂三丙烯微球行豚鼠子宫肌瘤模型进行子宫动脉栓塞操作的相关文献报道作者尚未查到。 目的：实验设计了以三丙烯微球进行豚鼠子宫肌瘤模型子宫动脉栓塞的可行性验证。 方法：30只成年雌性豚鼠随机分为两组：盆腔动脉铸型组10只,用于行盆腔血管铸型术,了解雌性豚鼠子宫动脉起源、行程、长度、直径及分支等解剖学特征;子宫肌瘤模型动脉栓塞组20只,应用雌孕激素联合法诱导子宫肌瘤模型建立,并行双侧子宫动脉微球栓塞的技术研究及病理分析。 结果与结论：双侧子宫动脉主干由髂内动脉发出,主干和弓状支的血管直径分别为(0.350±0.022) mm及(0.160±0.012) mm。子宫肌瘤模型动脉栓塞组20只豚鼠成功行双侧子宫动脉栓塞术。术中40~120 µm及100~300 µm三丙烯微球的用量分别为(0.040±0.005) mL和(0.017±0.002) mL。子宫肌瘤模型动脉栓塞组肌瘤成模率达75%。病理切片可见子宫动脉弓状支、浆膜下二级分支及部分三级分支动脉内均有栓塞微球存在。子宫肌层增厚,肌瘤结节处细胞呈栅栏状或编织状排列。栓塞后肌瘤缺血坏死明显,子宫肌层及内膜无缺血坏死病理改变。说明应用三丙烯微球行豚鼠子宫肌瘤模型动脉栓塞术具有可行性,栓塞效果良好。 关键词：三丙烯微球;子宫动脉栓塞术;豚鼠;子宫肌瘤;控制释放载体材料 doi:10.3969/j.issn.1673-8225.2010.08.012