Comparison of different infratentorial—supracerebellar approaches to the posterior and middle incisural space: a cadaveric study

2002 ◽  
Vol 97 (4) ◽  
pp. 922-928 ◽  
Author(s):  
Mario Ammirati ◽  
Antonio Bernardo ◽  
Angelo Musumeci ◽  
Albino Bricolo
Keyword(s):  
Anterior Part ◽  
Content Type ◽  
Regional Anatomy ◽  
Cadaveric Dissection ◽  
Dural Sinuses ◽  
Accurate Knowledge ◽  
Direct Exposure ◽  
Quadrigeminal Plate ◽  
Neurovascular Structures ◽  
Fine Print

Object. The purpose of this investigation was to describe and compare through cadaveric dissection the microsurgical exposure afforded by the median, paramedian, and extreme-lateral infratentorial—supracerebellar approaches to the posterior and middle incisural space. Methods. The median, paramedian, and extreme-lateral infratentorial—supracerebellar approaches were performed in 10 embalmed cadaveric heads by using standard microneurosurgical methods; each approach was executed a minimum of five times. The dissections were performed in a stepwise fashion, comparing the exposure afforded by each surgical route and highlighting the relationships among the targeted neurovascular structures. Exposure of the dural sinuses and transection of the tentorium were also evaluated in relation to the degree of exposure achieved. The median infratentorial—supracerebellar route provides direct exposure of the posterior incisural space, although the culmen represents a relative obstacle to exposure of the lower quadrigeminal plate. The paramedian variant allows a more lateral perspective on the posterolateral brainstem surface at the level of the middle incisural space, in addition to exposing the homolateral collicular plate. The extreme-lateral corridor widens the exposure of the paramedian approach to include the anterolateral brainstem surface, offering a complete view of the cisternal space surrounding the middle incisural space. Complete, constant exposure and retraction of the dural sinuses facilitated the surgical exposure. Conclusions. The infratentorial—supracerebellar approaches allow safe circumferential exposure of the posterior and middle incisural space. Choosing among different variants allows the surgeon to reach selected areas, with the midline variant being best for exposure of the posterior incisural space, and the paramedian and extreme-lateral variants being best for reaching the posterior and the anterior part of the middle incisural space, respectively. The more lateral the approach, the more anterior and multiangled the exposure gained. Complete, constant exposure and retraction of the dural sinuses improves the exposure. Accurate knowledge of the regional anatomy is mandatory.

Arteriovenous malformations in the posterior fossa

1977 ◽  
Vol 47 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Hiroshi Matsumura ◽  
Yasumasa Makita ◽  
Kuniyuki Someda ◽  
Akinori Kondo
Keyword(s):  
Arteriovenous Malformation ◽  
Brain Stem ◽  
Posterior Fossa ◽  
Arteriovenous Malformations ◽  
Cerebellopontine Angle ◽  
Anterior Part ◽  
Content Type ◽  
The Brain ◽  
Fine Print

✓ We have operated on 12 of 14 cases of arteriovenous malformation (AVM) in the posterior fossa since 1968, with one death. The lesions were in the cerebellum in 10 cases (three anteromedial, one central, three lateral, and three posteromedial), and in the cerebellopontine angle in two; in two cases the lesions were directly related to the brain stem. The AVM's in the anterior part of the cerebellum were operated on through a transtentorial occipital approach.

Exposure of the anterior part of the circle of Willis in the dog

1974 ◽  
Vol 41 (1) ◽  
pp. 107-112
Author(s):  
Shigeaki Hori ◽  
Williamina A. Himwich
Keyword(s):  
Anterior Part ◽  
Cerebral Arteries ◽  
Circle Of Willis ◽  
Content Type ◽  
Anatomical Characteristics ◽  
Fine Print

✓ A technique for exposing the vessels in the anterior part of the circle of Willis in the dog is described. Some of the physiological and anatomical characteristics of the anterior communicating and the anterior cerebral arteries are discussed.

Quadrant anatomy of the articular pillars (lateral cervical mass) of the cervical spine

1995 ◽  
Vol 82 (6) ◽  
pp. 1011-1014 ◽  
Author(s):  
T. Glenn Pait ◽  
Phillip V. McAllister ◽  
Howard H. Kaufman
Keyword(s):  
Anatomical Landmarks ◽  
Cervical Mass ◽  
Content Type ◽  
Bony Landmarks ◽  
Fixation Devices ◽  
Human Cadavers ◽  
Lateral Mass Screws ◽  
Neurovascular Structures ◽  
Lateral Facet ◽  
Fine Print

✓ Knowledge of the relevant anatomy is important when developing a strategy for introducing screws into the lateral masses to secure internal fixation devices. This paper defines key bony landmarks and their relationship to critical neurovascular structures and identifies a location for safe placement of cervical articular pillar (lateral mass) screws. Measurements of anatomical landmarks in 10 spines from human cadavers aged 61 to 85 years were made by caliper and a metric ruler. Landmarks were the lateral facet line, rostrocaudal line, medial facet line, intrafacet line, and medial facet line—vertebral artery line. The average distances and ranges were recorded. Such great variance existed in measurements from spine to spine and within the same spine as to render averages clinically unreliable. Dissection revealed that division of the articular pillar into four quadrants leaves one, the superior lateral quadrant, under which there are no neurovascular structures; this may be considered the “safe quadrant” for placement of posterior screws and plates.

Endoscopy of the posterior fossa and dissection of acoustic neuroma

1999 ◽  
Vol 91 (5) ◽  
pp. 776-780 ◽  
Author(s):  
Nebil Göksu ◽  
Yıldırım Bayazıt ◽  
Yusuf Kemaloğlu
Keyword(s):  
Posterior Fossa ◽  
Acoustic Neuroma ◽  
Residual Tumor ◽  
Lateral Aspect ◽  
Content Type ◽  
Retrolabyrinthine Approach ◽  
The Relationship ◽  
Neurovascular Structures ◽  
Internal Acoustic Canal ◽  
Fine Print

Object. The authors evaluated the importance of endoscopes in eliminating the disadvantages of the posterior fossa approach, such as the lack of adequate visualization of the lateral aspect of the internal acoustic canal (IAC).Methods. Between 1989 and 1998, 32 patients underwent removal of acoustic neuroma (AN) via a combined retrosigmoid—retrolabyrinthine approach. Endoscopes were used at different stages of the operation, and their use was evaluated with regard to elimination of the disadvantages of the posterior fossa approach. All patients in whom AN had been diagnosed underwent surgery in which a standard retrosigmoid—retrolabyrinthine approach was used. Standard sinus endoscopes of 0°, 30°, and 70° were introduced into the cerebellopontine angle before debulking the tumor, and the IAC was inspected at the end of the operation. Neurovascular integrity as well as the relationship between the AN and surrounding structures were evaluated. The IAC was inspected for residual tumor, and if any was found, endoscopically guided tumor dissection was performed.Conclusions. Endoscopes have facilitated an understanding of the anatomy between an AN and neighboring neurovascular structures. For surgery in which the posterior fossa approach is used, endoscopes can make operations safer by eliminating the disadvantages of the approach. In addition to allowing inspection of the fundus, it is possible to perform endoscopically guided tumor dissection within the IAC.

Intrasellar cavernous hemangioma

2001 ◽  
Vol 94 (3) ◽  
pp. 520-522 ◽  
Author(s):  
Charles S. Cobbs ◽  
Charles B. Wilson
Keyword(s):  
Cavernous Sinus ◽  
Cavernous Hemangioma ◽  
Pituitary Macroadenoma ◽  
Rare Entity ◽  
Content Type ◽  
Anatomical Features ◽  
Dural Sinuses ◽  
Fine Print

✓ The authors present a rare entity, an intrasellar cavernous hemangioma that on neuroimages mimicked a nonfunctioning pituitary macroadenoma in a patient with a known orbital hemangioma. Such lesions can grow extraaxially within the dural sinuses, particularly the cavernous sinus, and present like tumors. A better understanding of the neuroimaging, clinical, and anatomical features of these lesions may prevent difficulties in management.

Angiographic differentiation between Dandy-Walker cyst and arachnoid cyst of the posterior fossa in newborn infants and children

1973 ◽  
Vol 38 (3) ◽  
pp. 298-308 ◽  
Author(s):  
Emanuele La Torre ◽  
Aldo Fortuna ◽  
Emanuele Occhipinti
Keyword(s):  
Posterior Fossa ◽  
Arachnoid Cyst ◽  
Posterior Inferior Cerebellar Artery ◽  
Newborn Infants ◽  
Infants And Children ◽  
Arachnoid Cysts ◽  
Content Type ◽  
Dural Sinuses ◽  
Cerebellar Artery ◽  
Fine Print

✓ Elevation of the tentorium and its dural sinuses, originally considered a diagnostic sign of Dandy-Walker cyst, may also occur in arachnoid cysts of the posterior fossa. Differentiation between these two lesions may be achieved angiographically by the evaluation of the posterior inferior cerebellar artery and its vermian branch, and of the inferior vermian vein. All these vessels are displaced forward and upward by an arachnoid cyst, while in the Dandy-Walker cyst the posterior inferior cerebellar artery is miniature and the vermian branch and the inferior vermian vein are absent.

Peduncular hallucinosis due to a pineal meningioma

2001 ◽  
Vol 95 (3) ◽  
pp. 500-502 ◽  
Author(s):  
Takahito Miyazawa ◽  
Shinji Fukui ◽  
Naoki Otani ◽  
Nobusuke Tsuzuki ◽  
Hiroshi Katoh ◽  
...  
Keyword(s):  
Pineal Region ◽  
Visual Hallucinations ◽  
Content Type ◽  
First Report ◽  
Peduncular Hallucinosis ◽  
Quadrigeminal Plate ◽  
Fine Print

✓ The authors report the case of a 53-year-old woman who experienced visual hallucinations diagnosed as peduncular hallucinosis (PH). The cause of the PH was compression of the quadrigeminal plate and/or the splenium due to a meningioma originating from the falcotentorial junction (pineal meningioma). The nature of the visual hallucinations was depicted in drawings created by the patient herself. This is the first report of PH caused by a tumor located in the pineal region.

Timing of operation for ruptured supratentorial aneurysms: a prospective randomized study

1989 ◽  
Vol 70 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Juha Öhman ◽  
Olli Heiskanen
Keyword(s):  
Aneurysmal Subarachnoid Hemorrhage ◽  
Anterior Part ◽  
Controlled Trial ◽  
Randomized Study ◽  
Prospective Randomized Study ◽  
Double Blind ◽  
Content Type ◽  
Acute Surgery ◽  
Significant Difference ◽  
Fine Print

✓ A total of 216 patients with a ruptured aneurysm of the anterior part of the circle of Willis were enrolled into this prospective randomized study of timing of the operation after aneurysmal subarachnoid hemorrhage (SAH). Only patients in clinical Grades I to III (according to the classification of Hunt and Hess) who were admitted and randomly assigned to a treatment group within 72 hours after the SAH were included in the trial. The patients were randomly assigned to one of three operation groups: acute surgery (AS: 0 to 3 days after the SAH; day of SAH = Day 0), intermediate surgery (IS: 4 to 7 days after the SAH), or late surgery (LS: 8 days to an indefinite time after the SAH). Three patients (4.3%) in the IS group and six patients (8.6%) in the LS group died before surgery was undertaken. At 3 months post-SAH, 65 patients (91.5%) from the AS group were classified as independent compared to 55 (78.6%) from the IS group and 56 (80.0%) from the LS group. The management mortality rate in the AS group was 5.6% compared to 12.9% in the LS group. Of the 216 patients enrolled in the timing study, 159 were randomly assigned to an independent double-blind placebo-controlled trial of nimodipine in Grade I to III patients. A total of 79 patients received nimodipine and 80 placebo. When the nimodipine group and the no-nimodipine group (the 80 placebo-treated patients plus the 52 patients who were not entered into the nimodipine trial) were analyzed separately, a significant difference was seen in the outcome of the no-nimodipine group (dependent AS vs. dependent IS, p = 0.01). Nimodipine treatment was associated with a significant reduction of delayed ischemic deterioration (all operation groups combined, nimodipine vs. no nimodipine p = 0.01; LS with nimodipine vs. LS with no nimodipine, p = 0.03).

Results of early operations for ruptured aneurysms

1981 ◽  
Vol 54 (4) ◽  
pp. 473-479 ◽  
Author(s):  
Bengt Ljunggren ◽  
Lennart Brandt ◽  
Erik Kågström ◽  
Göran Sundbärg
Keyword(s):  
Anterior Part ◽  
Intracerebral Hematoma ◽  
Recurrent Bleeding ◽  
Consecutive Series ◽  
Good Recovery ◽  
Content Type ◽  
Urgent Surgery ◽  
Child Bearing ◽  
History Of ◽  
Fine Print

✓ In a consecutive series of 219 patients with a ruptured aneurysm of the anterior part of the circle of Willis, 119 patients (54%) made a good recovery and 67 (31%) died. Of 53 patients who did not have surgery, six (11%) made a good recovery and 37 (70%) died. Urgent surgery with evacuation of an associated significant intracerebral hematoma was performed in 30 patients; nine (30%) made a good recovery and 15 (50%) died. Delayed surgery was performed in 55 patients of whom 42 (76%) made a good recovery and two (4%) died. Early intracranial operation (within 48 to 60 hours after subarachnoid hemorrhage (SAH)) was performed in 81 patients who were in Grades I to III prior to surgery. Sixty patients (74%) made a good recovery, and eight died within a month. Five patients were severely disabled and died 2 to 8 months after SAH and surgery. In 17 patients, although the immediate postoperative course was uneventful, evidence of cerebral ischemia developed 4 to 13 days after the bleed and resulted in death in eight patients. A poor outcome was correlated with a history of elevated blood pressure before SAH. Seven patients, of whom six were women of child-bearing age, demonstrated pronounced vasospasm on postoperative angiography; nevertheless, they remained well and free from ischemic symptoms after surgery. Early operation combined with removal of subarachnoid clots and rinsing the basal cisterns does not eliminate the risk of delayed ischemic dysfunction. Such early surgery, however, improves overall outcome by preventing recurrent bleeding, and may also reduce the frequency of hydrocephalus.

Evaluation of varied surgical approaches used in the management of 170 far-lateral lumbar disc herniations: indications and results

1995 ◽  
Vol 83 (4) ◽  
pp. 648-656 ◽  
Author(s):  
Nancy E. Epstein
Keyword(s):  
Lumbar Disc ◽  
Degenerative Spondylolisthesis ◽  
Lateral Compartment ◽  
Surgical Approaches ◽  
Content Type ◽  
Direct Exposure ◽  
Disc Herniations ◽  
Complicating Factors ◽  
Far Lateral ◽  
Fine Print

✓ This study was undertaken to determine and compare indications and relative benefits of various surgical approaches in 170 patients (average age 55 years) with far-lateral herniated lumbar discs, identified by magnetic resonance (MR) imaging and computerized tomography (CT) and operated on between 1984 and 1994. Essentially three surgical procedures were performed: complete facetectomy in 73 patients, laminotomy with medial facetectomy in 39 patients, and intertransverse discectomy (also known as ITT) in 58 patients. Follow-up periods averaged 5 years (range 0.5–10 years). Outcomes were scored as excellent (no deficit), good (mild radiculopathy), fair (moderate radiculopathy), and poor (unchanged or worse). Overall, excellent and good results were achieved in 73 and 51 patients, respectively, and fair and poor results in 26 and 20, respectively. There was little difference among the results encountered for the three major surgical groups: 79% of the intertransverse (ITT) group had good-to-excellent outcomes, as compared with 70% of the facetectomy group, and 68% of the group who underwent at minimum laminotomy, and additional hemilaminectomy or laminectomy with medial facetectomy. Results were the same for the 121 patients followed for more than 2 years and for the 49 patients studied for under 2 years. In the management of far-lateral discs, total facetectomy provides the best exposure, but increases the risk of instability. Laminotomy and medial facetectomy uncover the lateral and subarticular recess and preserve stability, but visualization of the far-lateral compartment is often inadequate. The intertransverse approach offers extensive far-lateral but not medial intraforaminal exposure, while also preserving stability. Full facetectomy, laminotomy with medial facetectomy, and the intertransverse approaches yielded nearly comparable outcomes in far-lateral disc surgery. Only the full facetectomy exposes the entire course of the nerve root both medially and laterally, whereas the intertransverse procedure provides direct exposure of the far-lateral compartment alone. It is important to select the correct approach or combination of approaches to address attendant complicating factors such as spinal stenosis, spondyloarthrosis, and degenerative spondylolisthesis identified on CT and MR studies.

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