Microanatomy of the subependymal arteries of the lateral ventricle

BACKGROUND: Scarce information about the anatomy of the subependymal arteries (SEAs) is present in the scientific literature. METHODS: Twenty cerebral hemispheres with injected arteries were microdissected, and the magnetic resonance imaging scans of 100 patients with lacunar infarcts were examined. RESULTS: The SEAs were found to range in diameter from 40 to 490 microm (mean, 149 microm) and in number between 3 and 12 (average, 5.2). Of these, numbers from 1 to 3 originated from the anterior choroidal artery (AChA), between 1 and 10 from the lateral posterior choroidal artery (LPChA), 1 from the medial posterior choroidal artery (MPChA), and 1 from the internal carotid artery. The SEAs most often arose from the choroidal branches (90%) and less frequently from the thalamic (30%), caudate (35%), or thalamocaudate twigs (20%). The SEAs of the AChA supplied the walls of the temporal horn (100%), the occipital horn (85%), and the atrium (35%). Those of the LPChA perfused the walls of the occipital horn (15%), the atrium (65%), the body of the ventricle (100%), and partially the frontal horn. The SEAs of the MPChA partially nourished the body and the frontal horn (10%). The SEAs may also occasionally supply the caudate nucleus (20%) and the stria terminalis. The anastomoses involving the SEAs were absent. In spite of this, ischemia in the territory of a single SEA was noticed in only 1% of our patients. CONCLUSIONS: The SEAs are tiny vessels that supply the walls of the lateral ventricle, as well as the caudate nucleus and the stria terminalis occasionally. The obtained anatomic data can have important neurosurgical implications in intraventricular operations.     

Access to the posterior medial temporal lobe structures in the surgical treatment of temporal lobe epilepsy

The authors describe a surgical technique that allows access to the posterior temporal horn of the lateral ventricle with preservation of the most functional lateral temporal cortex. Development of the technique was stimulated by the need to resect posteromedial temporal lobe structures in patients with intractable complex partial epilepsy and well-identified unilateral posterior hippocampal foci. This technique has also been of value in the resection of some lateral ventricular and posteromedial temporal lobe masses. The operation consists of three steps. No more than 4.5 cm of the anterolateral temporal lobe is removed en bloc such that the most anterior aspect of the temporal horn is entered. An incision is carried from the floor of the temporal horn through the inferior longitudinal fasciculus to the middle fossa dura mater and posteriorally into the lateral ventricular atrium. The lateral temporal cortex and white matter are then elevated with a self-retaining retractor. This exposes the posteromedial temporal horn or intraaxial mass for excision or allows en bloc resection of the entire hippocampus and medial temporal lobe structures while preserving the functional association areas of the lateral temporal cortex, including speech and visual spatial function.     

A case of large basal ganglia AVM totally removed by staged operation

Large basal ganglia AVMs have been deemed inoperable because of their location in critical structures. Nonetheless, the unfavorable natural history of an untreated ruptured AVM in a young patient induced us to approach these lesions. We presented a case of a large basal ganglia AVM totally removed by a three-staged operation. A 26-year-old man who had twice experienced intracranial hemorrhage was admitted for examination. On admission, mild left hemiparesis, hypesthesia and left hemianopsia were disclosed. CT scan showed the AVM was located in the posterior thalamus with the hematoma cavity laterally. Right carotid and vertebral angiograms demonstrated a large AVM, 5cm in diameter, supplied by the anterior choroidal artery (AchoA), the lateral lenticulostriate arteries (I-LSAs), the lateral posterior choroidal artery (LPchoA) and the thalamo-perforating artery. Drainage was via the internal cerebral vein and the basal vein of Rosenthal. MRI demonstrated more clearly the anatomical relationship of the nidus and surrounding structures. The patient underwent a three staged operation. At the first operation AchoA was interrupted in the inferior horn of the lateral ventricle (IHL) via the hematoma cavity using the trans-sylvian approach. The anterior part of the nidus was dissected with all except one of the I-LSAs being disconnected. At the next operation by occipital interhemispheric approach, some feeders from the posterior cerebral artery were coagulated and disconnected. The medial and posterior part of the nidus was dissected from the thalamus along with the choroid plexus of the trigone of the lateral ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anatomy of the periventricular white matter

The lateral ventricle (LV) has a deep position within the cerebral hemisphere. The LV is covered by white matter with important functional role in the dominant hemisphere. Lateral wall of the frontal horn is covered by the inferior occipitofrontal fasciculus (IOFF) and its roof by the corpus callosum (CC). The body of the LV has the same cranial relationship and is covered laterally by fibers of internal capsula and arcuate fasciculus; its lower part is in relationship with the body of the fornix. The atrium of the LV is covered by the arcuate fasciculus and its lower part is covered by the IOFF and optic radiations. The inferior horn or temporal horn is covered by optic radiations in depth of middle temporal gyrus (T2). The auditive radiations crossed the optic radiations at the level of the roof of the inferior horn.     

Microvascular anatomy of the hippocampal formation.

The hippocampal vessels were examined in 25 forebrain hemispheres injected with india ink or methylmethacrylate. There were two to seven hippocampal arteries, which measured 200-800 microns in diameter. The anterior hippocampal artery (AHA), which was present in 88.2% of the hemispheres, most often originated from the posterior cerebral and the anterior temporal arteries, that is, within the rostral hippocampo-parahippocampal arterial complex. It arose from the anterior choroidal artery in 29.4% of the hemispheres. The AHA extended between the uncus and the parahippocampal gyrus, and it supplied the head of the hippocampus. The middle hippocampal artery was constant. It most often arose from the posterior cerebral and the common temporal arteries. The middle hippocampal artery coursed just caudal to the uncus, in close relationship with the lateral posterior choroidal artery, and it usually supplied the middle part of the hippocampal formation. The posterior hippocampal artery, which existed in 94.1% of the hemispheres, most often arose from the posterior cerebral and the splenial arteries. It irrigated the caudal part of the hippocampal formation. The anastomoses connecting the posterior, middle, and the anterior hippocampal arteries were present in 29.4% of the hemispheres. The hippocampal arteries gave rise to the straight vessels, which divided into the large and the small intrahippocampal arteries. The highest density of the capillary network was noted in the pyramidal and molecular layers of the hippocampal formation. The clinical significance of the obtained microanatomical findings is discussed.     

下腹部腹直肌肌皮瓣血供的应用解剖

目的了解与下腹部腹直肌肌皮瓣相关的血管分布情况,促进乳腺癌根治术后下腹部肌皮瓣移位乳房再造手术的推广。方法采用福尔马林浸泡未超过6个月的成人尸体15具30侧。上起锁骨下、下至腹股沟韧带,两侧至腋中线的胸腹壁完整切下。腹壁下动静脉自髂外动静脉起始处离断。分别用红、蓝乳胶墨水经腹壁下和胸廓内动静脉灌注,使其分支、属支显影。结果腹壁上、下动脉起始处外径分别为1.87±0.28mm及2.25±0.32mm。腹壁下动脉的皮下穿支分布有向脐水平逐渐密集的趋势,弓状线以下穿支明显减少,Rand各个区均可见穿支出腹直肌前鞘,排列上外侧穿支距腹直肌前鞘外侧缘、、区分别平均为1.22、1.46、1.57cm;内侧穿支在距正中线、、区平均1.54、1.62、1.66cm。近脐的穿支管径较其他部位粗和密集。腹壁上动脉在与肋弓下缘交界附近发出一肋缘动脉,距肋弓1.25±0.37cm。发出肋缘动脉后67%的肋缘动脉比腹壁下动脉本干粗。肋缘动脉分支分布于腹直肌中、外侧2/3,且与肋间前动脉及营养膈肌的血管间有广泛吻合。胸廓内动脉在发出腹壁上动脉前后还分出一分支营养剑突水平的腹直肌。结论以腹壁上动脉为蒂的横形下腹部肌皮瓣切取过程中,脐以下、弓状线以上保留腹直肌前鞘内、外侧各1cm在腹壁上和区的全部前鞘在皮瓣上,能较好保护腹壁下动脉肌皮动脉不受损伤。将肋弓下2cm以上的腹直肌前鞘和腹直肌完全保留在皮瓣上可有效保护肋缘动脉。肋缘动脉不受损是肌皮瓣成活的重要保证。     

Intraventricular occurrence of a melanocytoma

Melanocytomas are rare tumors of the central nervous system that are believed to arise from leptomeningeal melanocytes. A young girl presented with a contrast-enhancing cystic mass in the temporal horn of the left lateral ventricle. Microsurgical resection of a black-colored vascular tumor supplied by the anterior choroidal artery was performed. Appropriate immunohistochemical staining and electron microscope evaluations were used to confirm the pathological diagnosis. The patient made an excellent recovery; follow-up imaging revealed no recurrent or residual tumor. This is the first documented primary occurrence of a melanocytoma in an intraventricular location. The intraventricular occurrence of this tumor suggests that melanocytes may migrate into the choroidal fissure and may infrequently undergo neoplastic proliferation in that location. This case contains implications for the differential diagnosis of intraventricular tumors.     

Two adult cases of moyamoya disease with intraventricular hemorrhage--angiographic evaluation of periventricular vascular anatomy

In order to show the vascular anatomy in periventricular region, two adult cases of moyamoya disease with intracerebral hemorrhage extending into lateral ventricle were presented. And we discussed the relation between the vascular anatomy and the form of hemorrhage in moyamoya disease. The first case was a 46-year-old woman admitted for nausea and vomiting following headache for four days. CT scan revealed a high density area in the upper portion of body of right lateral ventricle showing intracerebral hemorrhage which extended into the lateral ventricle. On angiogram, typical moyamoya disease was noted. The ventriculofugal arteries from the posterior lateral choroidal artery was detected which indicated developed ventriculofugal perfusion. The second case was a 52-year-old man who was hospitalized sudden onset of headache, vomiting and consciousness disturbance. CT scan revealed a high density area suggesting of hemorrhage in the head of right caudate nucleus. It perforated into the right anterior horn of lateral ventricle with spreading over the other ventricles. We observed similar findings on the angiograms to the first case. In this case, however, the lateral striate arteries were involved instead of the posterior lateral choroidal artery. It should be pointed out that, in both cases, the area of hemorrhage in CT scan coincided with the area of developed ventriculofugal perfusion in angiograms.     

Bilateral PCL hypoplasia resulting in posterior, posterolateral rotatory instability and tears of the lateral meniscus anterior horn

This article describes a case of bilateral sagged knees presenting as posterior, posterolateral rotatory instability with tears of the anterior horn of the lateral meniscus. Each knee had identical tears of the lateral meniscus anterior horn. A 42-year-old woman reported bilateral anterior knee pain and painful instability during running or jarring exercises. She reported no major trauma to her knees. Arthroscopic findings of her right knee revealed a posterior cruciate ligament that looked hypoplastic but was without acute injury, and the anterior horn of the lateral meniscus showed chronic complex tears with some degeneration. Posterior cruciate ligament reconstruction, posterolateral corner sling, and meniscal repair of the lateral meniscus anterior horn was performed on her right knee. Three months later, a similar operation was performed on her left knee. However, menisectomy was performed because the lateral meniscus anterior horn tear was in the junction of the red-white and white zones. At 18 months postoperatively, the patient reported no symptoms and was satisfied with her results. Physical examination showed no joint line tenderness, and posterior stress radiographs on both knees showed grade I posterior instability. She showed no posterolateral subluxaion by supine dial test, and her prone dial test also improved approximately 15° on both knees. Lysholm score was 74 preoperatively and improved to 92 postoperatively.     

Detailed investigation of the relationship between the inferior laryngeal nerve including laryngeal branches and ligament of Berry

BACKGROUND: Studies about the anatomic relationship between the inferior laryngeal nerve (ILN) and the ligament of Berry are insufficient, despite controversy in the literature. In addition, the relationship between the laryngeal branches of the ILN and the ligament of Berry has not been investigated. STUDY DESIGN: Sixty specimens (120 sides) were examined for this study, including 41 male and 19 female cadavers between the ages of 40 and 89 years at death. RESULTS: The nerve trunk or its anterior and posterior laryngeal branches run posterolateral to the ligament in 51 and 39 sides, respectively. The nerve trunk or both its laryngeal branches passed posteromedial to the ligament in 12 and 7 sides, respectively. In seven sides, the anterior branch of the ILN was located posterolateral and the posterior branch was posteromedial to the ligament. In three sides, the anterior (motor) branch of the ILN penetrated the ligament of Berry. In one right side, a nonrecurrent laryngeal nerve arose from the vagal nerve at the level of ligament of Berry. The nerve divided into the anterior and posterior laryngeal branches just above posterior surface of the ligament; both branches extended parallel to it. CONCLUSIONS: We have shown that the nerve was located not only posterolateral to the ligament but also posteromedial to it. Additionally, unlike other authors, we have shown that the anterior (motor) branch of the recurrent laryngeal nerve penetrated the ligament of Berry in 2.5% of 60 specimens.     

Evaluation of postoperative flow reserve in internal mammary artery bypass grafts

The internal mammary artery has been advocated for use in bypass grafting owing to its superior long-term patency when compared to saphenous vein grafts. Concern exists that the flow through the internal mammary artery may be inadequate during periods of peak myocardial demand. This flow was investigated in 24 consecutive patients with a mean proximal left anterior descending artery stenosis of 87.5% who were selected for coronary bypass using the internal mammary artery. Within 8 weeks of operation, all were evaluated by exercise thallium 201 scintigraphy. Thallium activity, expressed as a ratio of anteroseptal activity to posterolateral wall activity (or inferior wall activity if the posterolateral wall was deemed abnormal), was 0.97 +/- 0.15. A second group of 25 patients, with normal coronary arteries, was similarly evaluated. The mean septal to posterolateral wall thallium activity ratio for these control patients was 1.0 +/- 0.15. A third group of 26 patients who underwent single-vessel percutaneous transluminal coronary angioplasty of the left anterior descending artery and a fourth group of 28 saphenous vein graft recipients were compared by stress thallium scintigraphy. Thallium 201 activity for the vein graft group (0.96 +/- 0.19) was not significantly different from that for the mammary artery group, whereas the flows obtained with a single attempt at angioplasty were significantly inferior (p less than 0.05). The internal mammary artery provides excellent coronary flow at peak myocardial demand and compares favorably to angioplasty and saphenous vein grafting.     

Saccular aneurysm of the distal anterior choroidal artery--case report.

The authors report a case of a distal anterior choroidal artery aneurysm in a 75-year-old female who presented with nausea, vomiting, and severe headache. Computed tomographic (CT) scans revealed a hematoma in the right lateral ventricle and a subarachnoid hemorrhage in the right parasellar-Sylvian cistern. Cerebral angiography showed a saccular aneurysm at the right distal anterior choroidal artery. The authors intended to operate at the chronic stage, and carried out conservative management. After 1 month her condition suddenly worsened and she died, although a CT scan showed no remarkable changes. At autopsy, a pulmonary artery thrombosis was considered the cause of death. The aneurysm was identified in the temporal horn of the right lateral ventricle, and was a true aneurysm.     

Revascularization of infarcted vs. viable myocardium. Effects on symptoms, physical performance and global/regional left ventricular function

Symptoms, physical performance and global vs. regional left ventricular (LV) function were reviewed in 25 patients with postinfarction anterior-apical akinesia and minor dyskinesia who subsequently underwent revascularization of all graftable stenotic vessels. The observed postoperative improvement in functional NYHA capacity and physical performance was not related to significant change in any systolic or diastolic variable of global LV function. 'Nonspecific postoperative septal hypokinesia' developed in most cases. The regional ejection fraction showed slight (nonsignificant) mean increase in the infarcted apex and low anterior wall supplied by the left anterior descending artery, but marked increase in the noninfarcted lateral wall supplied by the left circumflex branch. Hearts with grafted left circumflex artery showed on average lower preoperative and postoperative ejection fraction in the lateral wall than did hearts without such grafting, but the rise in regional ejection fraction was significant only after left circumflex grafting. The clinical response to coronary artery surgery is attributed mainly to functional improvement of non-infarcted myocardium. Revascularization of viable myocardium occurs directly via bypass grafts, but collateral vessels may also contribute.     

Rare tumors of the lateral ventricle. Review of the literature

Metastases of lateral ventricle (LV) are attached to choroidal plexus. Primary source is cancer of kidney. Two thirds of patients are male. Oligodendrogliomas occur in young females. Signs of increased intracranial pressure are a constant feature. These tumors are found in anterior portion of the LV with severe enhancement and clumped calcifications. Treatment is surgical. Cavernomas have a preponderance of rapid growth with a bleeding revelation. Seizures are rare. Rebleeding is frequent and justifies a surgical treatment. Schwannomas are a rare entity in which the majority of patients are very young. MRI shows calcifications, cystic components and a strong enhancement. They are limited to sporadic cases, never associated with neurofibromatosis. Arachnoid cysts are located in the atrium and/or in the occipital horn. Patients are young (mean age < 40 years). MRI demonstrates an intracystic lesion with signal intensity similar to the CSF. Best treatment is an endoscopic fenestration. Epidermoid cysts occur in third decade. These pearly tumors appear isointense or a little hyperintense on T1-weighted imaging, very characteristic. They are enhanced after gadolinium injection and appear strongly hyperintense on T2-weighted imaging. An incomplete removal with a thorough long-term follow-up is necessary. Cavernomas of LV are hyperintense on T1- and T2-weighted imaging. They have a bleeding risk of 25 to 45%. Therefore, they must be operated.     

Microsurgical anatomy of the insula and the sylvian fissure

OBJECT: The purpose of this study was to define the topographic anatomy, arterial supply, and venous drainage of the insula and sylvian fissure. METHODS: The neural, arterial, and venous anatomy of the insula and sylvian fissure were examined in 43 cerebral hemispheres. CONCLUSIONS: The majority of gyri and sulci of the frontoparietal and temporal opercula had a constant relationship to the insular gyri and sulci and provided landmarks for approaching different parts of the insula. The most lateral lenticulostriate artery, an important landmark in insular surgery, arose 14.6 mm from the apex of the insula and penetrated the anterior perforated substance 15.3 mm medial to the limen insulae. The superior trunk of the middle cerebral artery (MCA) and its branches supplied the anterior, middle, and posterior short gyri; the anterior limiting sulcus; the short sulci; and the insular apex. The inferior trunk supplied the posterior long gyrus, inferior limiting sulcus, and limen area in most hemispheres. Both of these trunks frequently contributed to the supply of the central insular sulcus and the anterior long gyrus. The areas of insular supply of the superior and inferior trunks did not overlap. The most constant insular area of supply by the cortical MCA branches was from the prefrontal and precentral arteries that supplied the anterior and middle short gyri, respectively. The largest insular perforating arteries usually arose from the central and angular arteries and most commonly entered the posterior half of the central insular sulcus and posterior long gyrus. Insular veins drained predominantly to the deep middle cerebral vein, although frequent connections to the superficial venous system were found. Of all the insular veins, the precentral insular vein was the one that most commonly connected to the superficial sylvian vein.     

Microsurgical anatomy of the choroidal fissure

The microsurgical anatomy of the choroidal fissure was examined in 25 cadaveric heads. The choroidal fissure, the site of attachment of the choroid plexus in the lateral ventricle, is located between the fornix and thalamus in the medial part of the lateral ventricle. The choroidal fissure is divided into three parts: (a) a body portion situated in the body of the lateral ventricle between the body of the fornix and the thalamus, (b) an atrial part located in the atrium of the lateral ventricle between the crus of the fornix and the pulvinar, and (c) a temporal part situated in the temporal horn between the fimbria of the fornix and the lower surface of the thalamus. The three parts of the fissure are the thinnest sites in the wall of the lateral ventricle bordering the basal cisterns and the roof of the third ventricle. Opening through the body portion of the choroidal fissure from the lateral ventricle exposes the velum interpositum and third ventricle. Opening through the temporal portion of the choroidal fissure from the temporal horn exposes the structures in the ambient and crural cisterns. Opening through the atrial portion of the fissure from the atrium exposes the quadrigeminal cistern, the pineal region, and the posterior portion of the ambient cistern. The neural, arterial, and venous relationships of each part of the fissure are reviewed. The operative approaches directed through each part of the fissure are also reviewed.     

Radiological diagnosis of the lateral ventricle tumor (author's transl)

The radiological characteristics of intraventricular tumors were studied with special reference to differential diagnosis from paraventricular tumors by careful analysis of seven cases intraventricular tumors and five cases paraventricular tumors. As, in the radiological term, intraventricular tumors have been dividied into two groups according to their location by Bernasconi et al., seven cases intraventricular tumors reported in this paper were also divided into two groups; 1) 2 cases ependymom occupying the frontal horn and the body of lateral ventricle, 2) 4 cases meningioma and one plexus papilloma occupying the trigone and the adjucent regions. In case of tumors belonged to group 1, the filling defect showing the circumference of tumors and the associated unilateral hydrocephalus were characteristic findings on the ventriculogram, while the depression of ventricular wall was observed in paraventricular tumors. Angiographic characteristics in group 1 tumors were the splay of subependymal veins of the medial group from those of lateral group and the increased density of deep veins due to raised circulation, and these findings demonstrated in all cases of ependymoma reported here. On the other hand, in all meningiomas belonged to group 2, the hypertrophia of choridal arteries was noticed in the angiogram. Moreover, the anterior choroidal artery was shown to be divided into two branches at its plexal segments, and the tumor stain at the trigone always lied between these two branches. We named this dissociation of these two plexal branches due to tumor as "flare sing". This is considered to be specific finding for a trigone meningioma, and this "flare sing" was observed in all of our 4 cases meningioma. In two cases out of four, the inferior ventricular vein was displaced anteriorly delineating the anterior margin of the tumor. This again is considered as a sign indicating the tumor occupying the trigone and adjacent regions.     

Anatomical relationship between insertion sites,tunnel placement,and lateral meniscus anterior horn injury during single and double bundle anterior cruciate ligament reconstructions: A comparative macroscopic and histopathological evaluation in cadavers

PurposeThe influence of tunnel extension outside the anatomical anterior cruciate ligament (ACL) insertion in single-bundle (SB) or double-bundle (DB) ACL reconstruction is unclear. This study aimed to investigate the anatomical relationship between ACL insertion and tunnel extension in SB and DB ACL reconstruction, and the impact of tibial tunnel extension to the insertion of anterior horn of lateral meniscus in terms of injury.MethodsForty-six paired cadaver knees (mean age, 82.7 ± 10.7 years) were used. Right and left knees were used for SB (10 mm) and DB tunnel reaming (6 mm for the anteromedial and posterolateral bundles). Tibial and femoral tunnels were created to aim at the center of the ACL insertion by arthroscopic visualization. The relationship between tunnel extension and ACL insertion was evaluated macroscopically, and there ratio in two groups were compared by chi-square test. Further, the relative risk for meniscus injury based on tunnel placement was estimated. Coronal section of tibia and parallel section to Blumensaat line in femur were prepared to evaluate the relationship among tunnel position, ACL insertion, and anterior horn of the meniscus histologically.ResultsTibial tunnel extension out of the ACL insertion was observed macroscopically in 9 (39.1%) knees of the SB group, and 3 (13.0%) of the DB group (p = 0.045). In femoral tunnels, extension out of the ACL insertion was seen in 8 (34.8%) knees of the SB group and 1 (4.3%) of the DB group (p = 0.011). Partial injuries of the lateral meniscus anterior horn (LMAH) were observed in 5 (21.7%) knees of the SB group and 1 (4.3%) knee of the DB group (p = 0.091). The relative risk for LMAH injury was calculated as 5.0 (odds ratio, 6.1). Microscopically, SB tunnels appeared to expand out of ACL insertion, both in the femur and tibia.ConclusionsThe incidence of tunnel extension out of the ACL insertion in femur and tibia were higher with SB than with DB reconstruction. Furthermore, injury rate of the LMAH in the DB group was lower.     

Anteromedial meniscofemoral ligament

We have experienced 3 cases of comparatively rare anteromedial meniscofemoral ligament in which the anterior horn of the medial meniscus was attached to the posterolateral wall of the femoral intercondylar fossa. In 2 of these cases, there was no attachment to the tibia, whereas in the other, it was connected to the lateral meniscus and also firmly to the tibia. In the 2 with no attachment to the tibia, abnormal mobility in the medial meniscus accompanied by flexion and extension of the knee was observed. Degeneration of the intermediate posterior segment and injury of the anterior horn were also observed. This anomaly induces a future meniscus injury, depending on the attachment state to the tibia.