Microsurgical treatment for unruptured intracranial aneurysms: a modern single surgeon series.

With the rise of endovascular treatments for the management of unruptured intracranial aneurysms (UIAs), advances in microsurgical techniques are underrepresented in modern surgical series, which largely consist of patients with aneurysms unfit for coiling. We report a modern series of microsurgical treatment for UIAs performed by a single surgeon as the preferred treatment modality. We retrospectively reviewed the charts of all patients with UIAs treated by the senior author with microsurgical clipping over an 11-year period. Procedure-related mortality, major neurologic morbidity (modified Rankin Score 3-5), complications, and persistent neurologic deficits were recorded. Risk factors for persistent neurologic deficits and major morbidity or mortality were analyzed using multivariate logistic regression analysis. We identified 329 patients with 400 UIAs treated in 353 surgeries. The average age was 52 years, 80% of patients were women, and 13% had a previous subarachnoid hemorrhage. The average aneurysm size was 7 mm and 92% were in the anterior circulation. The mean follow-up was 15 months (range 0.5-125). There was one procedure-related death (0.3%), and two patients suffered major morbidity (0.6%). Twenty procedures (5.6%) resulted in a persistent neurologic deficit. Risk factors for death and major morbidity were increasing age and posterior circulation, while risk factors for persistent neurologic deficits were increasing aneurysm size and posterior circulation. We conclude that microsurgical clipping is safe, effective, and should be given strong consideration as the primary treatment modality for younger patients with small to medium sized UIAs in the anterior circulation.

Inter-site and inter-scanner diffusion MRI data harmonization.

We propose a novel method to harmonize diffusion MRI data acquired from multiple sites and scanners, which is imperative for joint analysis of the data to significantly increase sample size and statistical power of neuroimaging studies. Our method incorporates the following main novelties: i) we take into account the scanner-dependent spatial variability of the diffusion signal in different parts of the brain; ii) our method is independent of compartmental modeling of diffusion (e.g., tensor, and intra/extra cellular compartments) and the acquired signal itself is corrected for scanner related differences; and iii) inter-subject variability as measured by the coefficient of variation is maintained at each site. We represent the signal in a basis of spherical harmonics and compute several rotation invariant spherical harmonic features to estimate a region and tissue specific linear mapping between the signal from different sites (and scanners). We validate our method on diffusion data acquired from seven different sites (including two GE, three Philips, and two Siemens scanners) on a group of age-matched healthy subjects. Since the extracted rotation invariant spherical harmonic features depend on the accuracy of the brain parcellation provided by Freesurfer, we propose a feature based refinement of the original parcellation such that it better characterizes the anatomy and provides robust linear mappings to harmonize the dMRI data. We demonstrate the efficacy of our method by statistically comparing diffusion measures such as fractional anisotropy, mean diffusivity and generalized fractional anisotropy across multiple sites before and after data harmonization. We also show results using tract-based spatial statistics before and after harmonization for independent validation of the proposed methodology. Our experimental results demonstrate that, for nearly identical acquisition protocol across sites, scanner-specific differences can be accurately removed using the proposed method.

Multidrug-resistant, progressive, invasive diffuse spinal aspergillosis: case report and review of the literature.

The authors describe a 65-year-old man who, after 7 years of complete remission from lung cancer, was found on routine oncologic follow imaging to have lesions on several vertebral bodies. Open biopsy of the affected thoracic vertebrae and surrounding soft tissue were negative for neoplasia. Bacteriology cultures revealed colonies of aspergillus fumigatus in all bone samples. Unlike most reported cases in which vertebral compromise rarely extends to more than two adjacent vertebrae, our patient had extensive compromise of the thoracic spine. This infection progressed despite treatment with antifungal regimens known to be effective, even in immunocompromised patients. Invasive aspergillosis of the spine is a rare and typically occurred in terminal patients. However, the spectrum of hosts and clinical presentations of invasive aspergillosis are increasing, due in part to better medical treatments that prolong the survival of patients with cancer, severe infections, and organ failure. In reviewing the literature, the authors discuss the currently available therapies for such infections of the spine, and highlight the growing incidence these and other formerly rare infections.

Evidence for the improved exposure of the ophthalmic segment of the internal carotid artery after anterior clinoidectomy: morphometric analysis.

BACKGROUND: Although resection of the anterior clinoid process (ACP) is valuable in the surgical treatment of aneurysms of the ophthalmic (C6) segment of the internal carotid artery (ICA), quantitative assessment of this adjunct is incomplete. Our morphometric study assesses the effectiveness of the anterior clinoidectomy for exposure of the C6 segment of the ICA. METHODS: Ten formalin-fixed adult cadaveric heads were dissected bilaterally and pterional craniotomies were performed bilaterally. Measurements before and after resection of the ACP included the length of C6 segment of the ICA on its lateral aspect; C6 segment length on its medial aspect; and medial length of the optic nerve from the optic chiasm to falciform ligament (before ACP resection) then to the annulus of Zinn (after ACP resection). FINDINGS: Height and width of the intradural ACP were 8.67 +/- 2.63 and 6.57 +/- 1.68 mm, respectively. After clinoidectomy, mean length of the lateral C6 segment of the ICA increased 60% and mean exposure of the medial C6 segment of the ICA increased 113% (p < 0.001). Exposure of the optic nerve increased 150% (p < 0.001) after clinoidectomy and sectioning of the falciform ligament. No correlations were found between the lengths of the ACP and entire C6 segment, or the ACP size and amount of the C6 segment covered by the clinoid. CONCLUSIONS: Exposure of the C6 segment of the ICA is markedly increased by increase of the mobility of the optic nerve with clinoidectomy and section of the falciform ligament.

Multiple, peripheral aneurysms of the anterior inferior cerebellar artery.

In this case report, a 49-year-old woman developed subarachnoid hemorrhage in the right cerebellopontine angle cistern and blood into the fourth ventricle from a ruptured peripheral aneurysm of the anterior inferior cerebellar artery (AICA) located at the meatal loop. Concomitantly, a contralateral peripheral aneurysm was found in the posterior inferior cerebellar artery (PICA). A second peripheral aneurysm, not identified by previous angiography, was found in the caudomedial branch of AICA. We describe this diagnostic dilemma, management, and review the clinical presentation and location of 84 other peripheral AICA aneurysms reported in the literature.

Evidence-based surgical treatment of carotid stenosis. Literature review.

Carotid stenosis is an important cause of transient ischemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis, which accounts for 10% to 20% of brain infarction cases. Despite the introduction of tissue-plasminogen activator and other promising experimental therapies for select patients with acute ischemic stroke prevention remains the best approach to reduce its impact. Stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well-established therapeutic target and a pillar of stroke prevention. Two main strategies exist for the treatment of carotid stenosis. The 1st is stabilization or halting the progression of the carotid plaque formation with medications and modifications of risk factors (e.g., hypertension, diabetes, smoking, obesity, high cholesterol). The 2nd approach is the elimination or reduction of carotid stenosis by carotid endarterectomy or angioplasty and stenting. Carotid endarterectomy is the mainstay of therapy for symptomatic, severe carotid stenosis. Although its role for asymptomatic patients appears more limited, it is distinct for severe stenosis. Carotid angioplasty and stenting are techniques in maturation with the attractiveness of being less invasive that face the challenge of at least replicating the results of surgery. In this article, we will discuss the surgical management of symptomatic and asymptomatic carotid stenosis based on the evidence provided by the literature.

Aneurysms of the ophthalmic (C6) segment of the internal carotid artery: treatment options and strategies based on a clinical series.

AIM: Treatment of ophthalmic segment aneurysms is technically demanding and still associated with a relatively high morbidity and mortality. The refinements of surgical techniques combined with the development of indirect methods of treatment have greatly improved the outcome in treating these lesions. We present our clinical experience and discuss treatment strategies. METHODS: Seventy-eight consecutive patients with 88 ophthalmic segment aneurysms were admitted to our service from January 1997 to June 2003. Forty-three patients presented with unruptured aneurysms and 35 presented with subarachnoid hemorrhage (SAH). Management strategies included surgical clipping alone in 53 patients, clipping and hemicraniectomy in 2, coiling in 17, external carotid artery-middle cerebral artery (ECA/MCA) by-pass in 2, and coil occlusion of the internal carotid artery in 2. Two patients underwent no treatment. RESULTS: In the group of 41 treated patients with unruptured aneurysms, 40 (97.6%) had good outcomes (GOS 1-2) and 1 patient had poor (GOS 3) outcome at discharge. Procedure-related morbidity was 15.7% (8/51 procedures), and permanent morbidity was 9.75% (4/41 patients). In the 35 patients who presented with SAH, mortality was 14.3% (5 patients); at discharge, 21 patients (60%) had good (GOS 1-2) and 9 (25.7%) poor (GOS 3) outcomes. The overall outcome was good (GOS 1-2) in 63 patients (80.8%) and poor (GOS 3-4) in 10 patients (12.8%). Overall mortality was 6.4% (5 patients all with SAH). CONCLUSIONS: Direct obliteration of the aneurysm utilizing advanced surgical techniques is our preferred treatment approach, whenever possible. In case of unclippable large or giant aneurysms, the surgical or endovascular occlusion of the proximal internal carotid artery with or without an extracranial-intracranial by-pass is an option. A highly skilled team including a cerebrovascular and an endovascular surgeon is essential to achieve good outcomes in treating these lesions.

Angiolipomas of the central nervous system.

Angiolipomas are neoplasms composed of mature adipocytes admixed with abnormal vascular elements. They are most commonly found in the subcutaneous tissue of the trunk and extremities, but other sites have been reported. The craniospinal axis is an uncommon but significant site. An extensive review of the literature is conducted. We summarize 94 cases of angiolipomas in the central nervous system (CNS) in 92 patients, including five in our own series, to highlight the most prominent features of these tumors. The increasing number of cases of CNS angiolipoma in the era of magnetic resonance imaging raises the question of the rarity of these lesions.