Microvascular anatomy of the medial temporal region

2021 ◽  
pp. 1-13

OBJECTIVE The authors investigated the microvascular anatomy of the hippocampus and its implications for medial temporal tumor surgery. They aimed to reveal the anatomical variability of the arterial supply and venous drainage of the hippocampus, emphasizing its clinical implications for the removal of associated tumors. METHODS Forty-seven silicon-injected cerebral hemispheres were examined using microscopy. The origin, course, irrigation territory, spatial relationships, and anastomosis of the hippocampal arteries and veins were investigated. Illustrative cases of hippocampectomy for medial temporal tumor surgery are also provided. RESULTS The hippocampal arteries can be divided into 3 segments, the anterior (AHA), middle (MHA), and posterior (PHA) hippocampal artery complexes, which correspond to irrigation of the hippocampal head, body, and tail, respectively. The uncal hippocampal and anterior hippocampal-parahippocampal arteries contribute to the AHA complex, the posterior hippocampal-parahippocampal arteries serve as the MHA complex, and the PHA and splenial artery compose the PHA complex. Rich anastomoses between hippocampal arteries were observed, and in 11 (23%) hemispheres, anastomoses between each segment formed a complete vascular arcade at the hippocampal sulcus. Three veins were involved in hippocampal drainage—the anterior hippocampal, anterior longitudinal hippocampal, and posterior longitudinal hippocampal veins—which drain the hippocampal head, body, and tail, respectively, into the basal and internal cerebral veins. CONCLUSIONS An understanding of the vascular variability and network of the hippocampus is essential for medial temporal tumor surgery via anterior temporal lobectomy with amygdalohippocampectomy and transsylvian selective amygdalohippocampectomy. Stereotactic procedures in this region should also consider the anatomy of the vascular arcade at the hippocampal sulcus.

2015 ◽  
Vol 74 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Fábio A. Nascimento ◽  
Luana Antunes Maranha Gatto ◽  
Carlos Silvado ◽  
Maria Joana Mäder-Joaquim ◽  
Marlus Sidney Moro ◽  
...  

ABSTRACT Objective To contribute our experience with surgical treatment of patients with mesial temporal lobe epilepsy (mTLE) undergoing anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SelAH). Method This is a retrospective observational study. The sample included patients with medically refractory mTLE due to unilateral mesial temporal sclerosis who underwent either ATL or SelAH, at Hospital de Clinicas – UFPR, from 2005 to 2012. We report seizure outcomes, using Engel classification, cognitive outcomes, using measurements of verbal and visuospatial memories, as well as operative complications. Result Sixty-seven patients (33 ATL, 34 SelAH) were studied; median follow-up was 64 months. There was no statistically significant difference in seizure or neuropsychological outcomes, although verbal memory was more negatively affected in ATL operations on patients’ dominant hemispheres. Higher number of major complications was observed in the ATL group (p = 0.004). Conclusion Seizure and neuropsychological outcomes did not differ. ATL appeared to be associated with higher risk of complications.


2018 ◽  
Vol 15 (6) ◽  
pp. E79-E80 ◽  
Author(s):  
Juan C Fernandez-Miranda

Abstract The medial temporal lobe can be divided in anterior, middle, and posterior segments. The anterior segment is formed by the uncus and hippocampal head, and it has extra and intraventricular structures. There are 2 main approaches to the uncohippocampal region, the anteromedial temporal lobectomy (Spencer's technique) and the transsylvian selective amygdalohippocampectomy (Yasargil's technique). In this video, we present the case of a 29-yr-old man with new onset of generalized seizures and a contrast-enhancing lesion in the left anterior segment of the medial temporal lobe compatible with high-grade glioma. He had a medical history of cervical astrocytoma at age 8 requiring craniospinal radiation therapy and ventriculoperitoneal shunt placement. The tumor was approached using a combined transsylvian transcisternal and transinferior insular sulcus approach to the extra and intraventricular aspects of the uncohippocampal region. It was resected completely, and the patient was neurologically intact after resection with no further seizures at 6-mo follow-up. The diagnosis was glioblastoma IDH-wild type, for which he underwent adjuvant therapy. Surgical anatomy and technical nuances of this approach are illustrated using a 3-dimensional video and anatomic dissections. The selective approach, when compared to an anteromedial temporal lobectomy, has the advantage of preserving the anterolateral temporal cortex, which is particularly relevant in dominant-hemisphere lesions, and the related fiber tracts, including the inferior fronto-occipital and inferior longitudinal fascicles, and most of the optic radiation fibers. The transsylvian approach, however, is technically and anatomically more challenging and potentially carries a higher risk of vascular injury and vasospasm. Page 1 and figures from Fernández-Miranda JC et al, Microvascular Anatomy of the Medial Temporal Region: Part 1: Its Application to Arteriovenous Malformation Surgery, Operative Neurosurgery, 2010, Volume 67, issue 3, ons237-ons276, by permission of the Congress of Neurological Surgeons (1:26-1:37 in video). Page 1 from Fernández-Miranda JC et al, Three-Dimensio-nal Microsurgical and Tractographic Anatomy of the White Matter of the Human Brain, Neurosurgery, 2008, Volume 62, issue suppl_3, SHC989-SHC1028, by permission of the Congress of Neurological Surgeons (1:54-1:56 in video).


Neurosurgery ◽  
2017 ◽  
Vol 81 (6) ◽  
pp. 992-1004 ◽  
Author(s):  
Barbara Schmeiser ◽  
Kathrin Wagner ◽  
Andreas Schulze-Bonhage ◽  
Irina Mader ◽  
Anne-Sophie Wendling ◽  
...  

Abstract BACKGROUND Mesiotemporal lobe epilepsy is one of the most frequent causes for pharmacoresistant epilepsy. Different surgical approaches to the mesiotemporal area are used. OBJECTIVE To analyze epileptological and neuropsychological results as well as complications of different surgical strategies. METHODS This retrospective study is based on a consecutive series of 458 patients all harboring pharmacoresistant mesiotemporal lobe epilepsy. Following procedures were performed: standard anterior temporal lobectomy, anterior temporal or key-hole resection, extended lesionectomy, and transsylvian and subtemporal selective amygdalohippocampectomy. Postoperative outcome was evaluated according to different surgical procedures. RESULTS Overall, 1 yr after surgery 315 of 432 patients (72.9%) were classified Engel I; in particular, 72.8% were seizure-free after anterior temporal lobectomy, 76.9% after key-hole resection, 84.4% after extended lesionectomy, 70.3% after transylvian selective amygdalohippocampectomy, and 59.1% after subtemporal selective amygdalohippocampectomy. No significant differences in seizure outcome were found between different resective procedures, neither in short-term nor long-term follow-up. There was no perioperative mortality. Permanent morbidity was encountered in 4.4%. There were no significant differences in complications between different resection types. In the majority of patients, selective attention improved following surgery. Patients after left-sided operations performed significantly worse regarding verbal memory as compared to right-sided procedures. However, surgical approach had no significant effect on memory outcome. CONCLUSION Different surgical approaches for mesiotemporal epilepsy analyzed resulted in similar epileptological, neuropsychological results, and complication rates. Therefore, the approach for the individual patient does not only depend on the specific localization of the epileptogenic area, but also on the experience of the surgeon.


2018 ◽  
Vol 11 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Olivia Winkler ◽  
Waleed Brinjikji ◽  
Heinrich Lanfermann ◽  
Friedhelm Brassel ◽  
Dan Meila

Background and purposeIt is classically thought that the internal cerebral veins (ICV) do not communicate with the venous pouch of vein of Galen malformations (VGM). We report on the anatomy of the deep venous system in VGM with special emphasis on the drainage of the ICV and possible changes after endovascular treatment.Materials and methodsWe retrospectively analyzed DSA and 2D time-of-flight MR venograms of 55 children with VGM. We evaluated all pre- and post-operative images for the presence of the ICVs and determined their route of venous drainage.ResultsOf 55 children, pre-operative 2D MRV detected the ICVs in 19 cases (35%) compared with one case (2%) for pre-embolization DSA (2%) (P<0.0001). Of the cases in which the ICVs were seen preoperatively, in 15 cases (78.9%) the ICV drained directly into the VGM while in the other four cases, the ICV used alternative venous drainage routes. On post-operative MRV, the ICVs were seen in 17 cases (31%) on MRV and 10 cases (18.2%) on DSA with drainage into an adult-like vein of Galen in 13 cases (76%), respectively (P=0.08). In four cases normal ICV drainage into the vein of Galen was seen even when the venous sac was closed. In two cases there was a change in ICV drainage from the vein of Galen to the lateral mesencephalic vein.ConclusionThe communication of the ICV with the VGM is a common phenomenon. Different changes of venous drainage routes do occur after treatment and are best seen on MRV.


Neurosurgery ◽  
2011 ◽  
Vol 68 (1) ◽  
pp. 98-107 ◽  
Author(s):  
Olaf E M G. Schijns ◽  
Christian G. Bien ◽  
Michael. Majores ◽  
Marec. von Lehe ◽  
Horst. Urbach ◽  
...  

Abstract BACKGROUND: Temporal lobe gray-white matter abnormalities (GWMA) are frequent morphological aberrances observed on MRI in patients with temporal lobe epilepsy (TLE) in addition to hippocampal sclerosis (HS). OBJECTIVE: To study the influence of temporal pole GWMA on clinical characteristics and seizure outcome in patients with HS operated on for TLE. METHODS: A cohort of 370 patients undergoing surgery for intractable TLE was prospectively collected in an epilepsy surgery data base. Clinical characteristics and seizure outcome of all 58 TLE patients with identified HS and GWMA (group 1) were compared with those of a matched control group of 58 HS patients without GWMA (group 2). Both groups were further subdivided into patients undergoing transsylvian selective amygdalohippocampectomy (sAH) and anterior temporal lobectomy with amygdalohippocampectomy (ATL). RESULTS: The HS plus GWMA patients were significantly younger at epilepsy onset than those without GWMA. In the HS plus GWMA group, 41% of patients were younger than 2 years when they experienced their first seizure in contrast to only 17% of patients with pure HS (P = .004). Seizure outcome was not statistically different between the 2 groups: 75.9% of the patients in group 1 were seizure free (Engel class I) compared with 81% of patients in group 2. Seizure outcome in both groups was about equally successful with selective amygdalohippocampectomy and anterior temporal lobectomy (ns). CONCLUSION: Limited and standard resections in TLE patients with HS are equally successful regardless of the presence of GWMA.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Leonard L Yeo ◽  
Ben Wakerley ◽  
Liang Shen ◽  
Aftab Ahmad ◽  
Kay W Ng ◽  
...  

Background- Significant numbers of acute ischemic stroke (AIS) patients recover with timely-administered intravenous tissue plasminogen activator (IV-TPA). However, rates and extent of recovery remain variable. Considering scarce and costly resources, early identification of reliable predictors for functional outcomes is important for planning rehabilitation strategies. We hypothesized that venous drainage would be impaired on the side of cerebral hypoperfusion due to acute occlusion of internal carotid or middle cerebral artery. The 2 internal cerebral veins (ICV) drain the deep parts of hemispheres and run backward to form great cerebral vein. Since ICVs are consistently seen on CT angiography (CTA), parallel and run very close to each other, even minor asymmetry in their filling can be easily diagnosed. ICV asymmetry in pre-TPA CTA can change in patients achieving arterial recanalization, rendering it less useful for predicting the long-term outcomes. Thus, we aimed at evaluating whether the presence of ICV asymmetry on follow-up CTA can predict the final outcome. Methods- Data from consecutive AIS patients treated with IV-TPA, in a standardized protocol, from Jan2007 to March2010 were included in a prospective registry at our tertiary center. In this study, we excluded posterior circulation strokes. Significant proportion AIS patients undergo CTA on day 2 after IV-TPA to assess the status of arterial patency. ICV asymmetry was assessed by 2 independent stroke neurologists/ neuroradiologists, blinded to patient data or outcomes. Functional outcomes were assessed by modified Rankin Scale (mRS) at 3-months, dichotomized as good outcome (mRS 0-1) and poor outcome (mRS 2-6). Data were analyzed for the early predictors of function outcome. Results- Of the total of 2238 patients admitted during the study period, 226 (10.1%) with anterior circulation AIS treated with intravenous thrombolysis were included. Median age was 65yrs (range 19-92), 63% males and median National Institute of Health Stroke Scale (NIHSS) 16points (range 4-32). Hypertension was the commonest vascular risk factor in 144 (76%) while 63 (33%) patients suffered from atrial fibrillation (AF). Overall, 108 (47.8%) patients achieved poor functional outcome at 3-months. ICV asymmetry could be assessed only in 103 (45.5%) patients on their follow up CTA films. Admission NIHSS score (OR1.08;95%CI 1.001-1.157,p=0.048) and ICV asymmetry on follow-up CT scan (OR 23.9;95%CI 5.15-63.99,p <0.0001) were associated with poor outcome at 3-months. Conclusion- Presence of the asymmetry of internal cerebral veins on the follow up CT angiography in acute ischemic stroke patients treated with IV-TPA can be used as an early predictor of poor functional outcome.


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