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Christoph J. Griessenauer, Paul M. Foreman, John P. Deveikis and Mark R. Harrigan

The pathophysiology of extracranial traumatic aneurysm formation has not been fully elucidated. Intraarterial optical coherence tomography (OCT), an imaging modality capable of micrometer cross-sectional resolution, was used to evaluate patients presenting with saccular traumatic aneurysms of the internal carotid artery (ICA). Two consecutive trauma patients diagnosed with saccular traumatic aneurysms of the cervical ICA, per the institutional screening protocol for traumatic cerebrovascular injury, underwent digital subtraction angiography (DSA) with OCT. Optical coherence tomography demonstrated disruption of the intima with preservation and stretching of the more peripheral layers. In 1 patient the traumatic aneurysm was associated with thrombus formation and a separate, more proximal dissection not visible on CT angiography (CTA) or DSA. Imaging with OCT indicates that saccular traumatic aneurysms may develop from disruption of the intima with at least partial preservation of the media and adventitia. This provides in vivo evidence that saccular traumatic aneurysms result from a partial arterial wall tear rather than complete disruption. Interestingly, OCT was also able to detect arterial injury and thrombi not visible on CTA or DSA.

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Siyu Shi, Raghav Gupta, Justin M. Moore, Christoph J. Griessenauer, Nimer Adeeb, Rouzbeh Motiei-Langroudi, Ajith J. Thomas and Christopher S. Ogilvy

Brain arteriovenous malformations (AVMs) are traditionally considered congenital lesions, arising from aberrant vascular development during the intrauterine period. Rarely, however, AVMs develop in the postnatal period. Individual case reports of de novo AVM formation in both pediatric and adult patients have challenged the traditional dogma of a congenital origin. Instead, for these cases, a dynamic picture is emerging of AVM growth and development, initially triggered by ischemic and/or traumatic events, coupled with genetic predispositions. A number of pathophysiological descriptions involving aberrant angiogenic responses following trauma, hemorrhage, or inflammation have been proposed, although the exact etiology of these lesions remains to be elucidated. Here, the authors present 2 cases of de novo AVM formation in adult patients. The first case involves the development of an AVM following a venous sinus thrombosis and to the authors' knowledge is the first of its kind to be reported in the literature. They also present a case in which an elderly patient with a previously ruptured AVM developed a second AVM in the contralateral hemisphere 11 years later. In addition to presenting these cases, the authors propose a possible mechanism for de novo AVM development in adult patients following ischemic injury.

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Raghav Gupta, Christoph J. Griessenauer, Justin M. Moore, Nimer Adeeb, Apar S. Patel, Christopher S. Ogilvy and Ajith J. Thomas

OBJECTIVE

Given the highly complex and demanding clinical environment in which neurosurgeons operate, the probability of facing a medical malpractice claim is high. Recent emphasis on tort reform within the political sphere has brought this issue to the forefront of medical literature. Despite the widespread fear of litigation in the medical community, few studies have provided an analysis of malpractice litigation in the field. Here, the authors attempt to delineate the medicolegal factors that impel plaintiffs to file medical malpractice claims related to the management of brain aneurysms, and to better characterize the nature of these lawsuits.

METHODS

The online legal database WestLawNext was searched to find all medical malpractice cases related to brain aneurysms across a 30-year period. All state and federal jury verdicts and settlements relevant to the search criterion were considered.

RESULTS

Sixty-six cases were obtained. The average age of the patient was 46.7 years. Seventy-one percent were female. The cases were distributed across 16 states. The jury found in favor of the plaintiff in 40.9% of cases, with a mean payout of $8,765,405, and in favor of the defendant in 28.8% of the cases. A failure to diagnose and/or a failure to treat in a timely manner were the 2 most commonly alleged causes of malpractice. Settlements, which were reached in 25.8% of the cases, had a mean payout of $1,818,250. Neurosurgeons accounted for 6.7% of all defendants.

CONCLUSIONS

Unlike other medical specialties, a majority of the verdicts were not in the defendant's favor. The mean payouts were nearly 5-fold less in cases in which a settlement was reached, as opposed to a summary judgment. Neurosurgeons accounted for a small percentage of all codefendants.

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Ajith J. Thomas, Christopher S. Ogilvy, Christoph J. Griessenauer and Khalid A. Hanafy

OBJECTIVE

Even though heme-induced cerebral inflammation contributes to many of the adverse sequelae seen in patients with subarachnoid hemorrhage (SAH), little is known about the mechanism; mouse models have shown a critical role for macrophages/microglia. Macrophage CD163 is a hemoglobin scavenger receptor involved in blood clearance after SAH. The authors hypothesized that the modified Fisher score is independently associated with cerebrospinal fluid (CSF) macrophage CD163 expression on postictal day 1, and that CSF macrophage CD163 expression is associated with 1-month neurological outcome.

METHODS

CSF macrophages from 21 SAH and 28 unruptured aneurysm patients (control) were analyzed for CD163 expression using flow cytometry and confocal microscopy on postictal day 1. Significant associations with modified Fisher scale grades or modified Rankin Scale scores were determined using linear regression and a matched case control analysis.

RESULTS

CSF macrophage CD163 expression was significantly increased in SAH patients compared with controls (p < 0.001). The modified Fisher scale (mF) grades (β = 0.407, p = 0.005) and CSF bilirubin concentrations (β = 0.311, p = 0.015) were positively and independently associated with CSF macrophage CD163 expression when the analysis was controlled for age and sex. CSF macrophages from an SAH patient with a high mF grade had increased co-localization of CD163 and glycophorin A (CD235a, an erythrocyte marker) compared with those from an SAH patient with a low mF grade. The controls had no co-localization. CSF macrophage CD163 expression (p = 0.003) was inversely associated with 1-month neurological outcome, when SAH patients were matched based on mF grade.

CONCLUSIONS

This early study suggests that CSF macrophage CD163 expression, as measured by flow cytometry, may have some neuroprotective function given its inverse association with outcome and provides unique insights into the neuroinflammatory process after SAH.

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Paul M. Foreman, Christoph J. Griessenauer, Michael Falola and Mark R. Harrigan

Object

Traumatic aneurysms occur in 10% of extracranial blunt traumatic cerebrovascular injuries (TCVI). The clinical consequences and optimal management of traumatic aneurysms are poorly understood.

Methods

A prospective study of TCVI at a Level I trauma center identified 7 patients with 19 extracranial traumatic carotid artery or vertebral artery aneurysms. An additional 6 patients with 7 traumatic aneurysms were followed outside of the prospective study, giving a total of 13 patients with 26 traumatic aneurysms. All patients were treated with 325 mg aspirin daily and underwent clinical and imaging follow-up beyond the initial hospitalization. Endovascular treatment was reserved for aneurysms demonstrating significant enlargement on follow-up imaging. Clinical and radiographic features were assessed.

Results

The 7 patients with traumatic aneurysms identified in the prospective cohort comprised 10.3% of all patients with TCVI. Two (15.4%) of the 13 total patients suffered an ischemic stroke in the setting of TCVI with traumatic aneurysm formation. No patient experienced an ischemic stroke or new symptoms after the initiation of antiplatelet therapy. Clinical and radiographic follow-up averaged 15.8 months (range 0.4–41.7 months) and 22.0 months (range 6.6–55.7 months), respectively. Ten (38.5%) of 26 aneurysms were not visualized on last follow-up, 10 (38.5%) were smaller, 1 (3.8%) was unchanged, and 5 (19.2%) were larger. Saccular aneurysms were more likely to enlarge than fusiform aneurysms (33.3% vs 11.8%). Results of a Fisher exact test tend to support the assertion that the 2 different aneurysm morphologies behave differently (p = 0.07). Two saccular aneurysms were treated with stenting.

Conclusions

The majority of traumatic aneurysms can be managed with an antiplatelet regimen of 325 mg aspirin daily and serial imaging. Saccular aneurysms have a greater tendency to enlarge when compared with fusiform aneurysms.

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Paul M. Foreman, Christoph J. Griessenauer, Michelle Chua, Mark N. Hadley and Mark R. Harrigan

OBJECT

Approximately 10% of patients with blunt traumatic extracranial cerebrovascular injury have a complete occlusion of the vertebral artery (VA). Ischemic stroke due to embolization of thrombus from an occluded VA following cervical spine surgery has been observed. The risk of ischemic stroke with cervical spine surgery in the presence of an occluded VA, however, has never been determined.

METHODS

A retrospective chart review of 52 patients with a VA occlusion following a blunt trauma was performed. Clinical and radiographic characteristics were collected and analyzed.

RESULTS

Ten patients (19.2%) suffered an ischemic stroke attributable to a traumatic VA occlusion. Univariate analysis demonstrated that patients with ischemic stroke were significantly older (p = 0.042) and had a lower rate of cervical spine surgery (p < 0.005). Multivariate analysis found cervical spine surgery to be protective against ischemic stroke (OR 0.049 [95% CI 0.014–0.167], p = 0.014); increasing age and bilateral VA injury (bilateral occlusion or unilateral occlusion with contralateral dissection) were risk factors for ischemic stroke (OR 1.05 [95% CI1.02–1.07], p = 0.065 and OR 13.2 [95% CI 2.98–58.9], p = 0.084, respectively).

CONCLUSIONS

Traumatic VA occlusion is associated with a risk of ischemic stroke and mortality. Corrective cervical spine surgery potentially decreases the risk of ischemic stroke by stabilizing the spine and thereby reducing motion across the occluded segment of the VA and preventing embolization of thrombus. While a high stoke risk may be inherent to the disease, novel therapies should be investigated.

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Christoph J. Griessenauer, Elias Rizk, Joseph H. Miller, Philipp Hendrix, R. Shane Tubbs, Mark S. Dias, Kelsie Riemenschneider and Joshua J. Chern

Object

Tectal plate gliomas are generally low-grade astrocytomas with favorable prognosis, and observation of the lesion and management of hydrocephalus remain the mainstay of treatment.

Methods

A cohort of patients with tectal plate gliomas at 2 academic institutions was retrospectively reviewed.

Results

Forty-four patients with a mean age of 10.2 years who harbored tectal plate gliomas were included in the study. The mean clinical and radiological follow-up was 7.6 ± 3.3 years (median 7.9 years, range 1.5–14.7 years) and 6.5 ± 3.1 years (median 6.5 years, range 1.1–14.7 years), respectively. The most frequent intervention was CSF diversion (81.8% of patients) followed by biopsy (11.4%), radiotherapy (4.5%), chemotherapy (4.5%), and resection (2.3%). On MR imaging tectal plate gliomas most commonly showed T1-weighted isointensity (71.4%), T2-weighted hyperintensity (88.1%), and rarely enhanced (19%). The initial mean volume was 1.6 ± 2.2 cm3 and it increased to 2.0 ± 4.4 cm3 (p = 0.628) at the last follow-up. Frontal and occipital horn ratio (FOHR) and third ventricular width statistically decreased over time (p < 0.001 and p < 0.05, respectively).

Conclusions

The authors' results support existing evidence that tectal plate gliomas frequently follow a benign clinical and radiographic course and rarely require any intervention beyond management of associated hydrocephalus.

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Christoph J. Griessenauer, R. Shane Tubbs, Mohammadali M. Shoja, Joel Raborn, Christopher J. Boes, Martin M. Mortazavi and Giuseppe Lanzino

Alfred W. Adson was a pioneer in the field of neurosurgery. He described operations for a variety of neurosurgical diseases and developed surgical instruments. Under his leadership the Section of Neurological Surgery at the Mayo Clinic was established and he functioned as its first chair. Adson's contributions to the understanding of spinal and spinal cord tumors are less well known. This article reviews related medical records and publications and sets his contributions in the context of the work of other important pioneers in spinal tumor surgery at the time.

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Raghav Gupta, Nimer Adeeb, Christoph J. Griessenauer, Justin M. Moore, Apar S. Patel, Christopher Kim, Ajith J. Thomas and Christopher S. Ogilvy

OBJECTIVE

Health care education resources are increasingly available on the Internet. A majority of people reference these resources at one point or another. A threshold literacy level is needed to comprehend the information presented within these materials. A key component of health literacy is the readability of educational resources. The National Institutes of Health (NIH) and the American Medical Association have recommended that patient education materials be written between a 4th- and a 6th-grade education level. The authors assessed the readability of online patient education materials about brain aneurysms that have been published by several academic institutions across the US.

METHODS

Online patient education materials about brain aneurysms were downloaded from the websites of 20 academic institutions. The materials were assessed via 8 readability scales using Readability Studio software (Oleander Software Solutions), and then were statistically analyzed.

RESULTS

None of the patient education materials were written at or below the NIH's recommended 6th-grade reading level. The average educational level required to comprehend the texts across all institutions, as assessed by 7 of the readability scales, was 12.4 ± 2.5 (mean ± SD). The Flesch Reading Ease Scale classified the materials as “difficult” to understand, correlating with a college-level education or higher. An ANOVA test found that there were no significant differences in readability among the materials from the institutions (p = 0.215).

CONCLUSIONS

Brain aneurysms affect 3.2% of adults 50 years or older across the world and can cause significant patient anxiety and uncertainty. Current patient education materials are not written at or below the NIH's recommended 4th- to 6th-grade education level.