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.
Siyu Shi, Raghav Gupta, Justin M. Moore, Christoph J. Griessenauer, Nimer Adeeb, Rouzbeh Motiei-Langroudi, Ajith J. Thomas, and Christopher S. Ogilvy
Raghav Gupta, Christoph J. Griessenauer, Justin M. Moore, Nimer Adeeb, Apar S. Patel, Christopher S. Ogilvy, and Ajith J. Thomas
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.
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.
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.
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.
Yosuke Akamatsu, Santiago Gomez-Paz, Justin M. Moore, Christopher S. Ogilvy, and Ajith J. Thomas
Cervical arterial tortuosity is not uncommon in patients with spontaneous carotid artery dissections (CADs), but the tortuosity often precludes endovascular stent reconstruction. The authors report 2 cases of emergency recanalization of a carotid tonsillar loop dissection using a Pipeline embolization device (PED).
Two patients presented with symptomatic CAD involving tonsillar looping of the cervical internal carotid artery (ICA). Although the tonsillar loop prevented navigation of the carotid and peripheral stent delivery system, a PED was easily navigated and successfully deployed, resulting in successful recanalization of a looped ICA.
Emergency recanalization of a cervical CAD using a PED is a feasible alternative for treating a cervical CAD associated with tonsillar loops.
Justin F. Fraser, Gurston G. Nyquist, Nicholas Moore, Vijay K. Anand, and Theodore H. Schwartz
Transcranial approaches to clival chordomas provide a circuitous route to the site of origin of the tumor often involving extensive bone drilling and brain retraction, which places critical neurovascular structures between the surgeon and pathology. For certain chordomas, the endonasal endoscopic transclival approach is a novel minimal access, but it is an equally aggressive alternative providing the most direct route to the tumor epicenter.
The authors present a consecutive series of patients undergoing endonasal endoscopic resection of clival chordomas. Extent of resection was determined by postoperative volumetric MR imaging and divided into > 95% and < 95%.
Seven patients underwent 10 operations. Preoperative cranial neuropathies were present in 4. The mean patient age was 52.0 years. The mean tumor volume was 34.9 cm3. Intraoperative lumbar drainage was used in 1 patient, and the tumors extended intradurally in 3. One patient underwent 2 intentionally palliative procedures for subtotal debulking. Greater than 95% resection was achieved in 7 of 8 operations in which radical resection was the goal (87%). All tumors with volumes < 50 cm3 had > 95% resection (p = 0.05). The overall mean follow-up was 18.0 months. Cranial neuropathies resolved in all 3 patients with cranial nerve VI palsies. One patient with recurrent nasopharyngeal chordoma died of disease progression; another experienced 2 recurrences before receiving radiation therapy. All surviving patients remain progression free. There were no intraoperative complications; however, 1 patient developed a pulmonary embolus postoperatively. There were no postoperative CSF leaks.
The endonasal endoscopic transclival approach represents a less invasive and more direct approach than a transcranial approach to treat certain moderate-sized midline skull base chordomas. Longer follow-up is necessary to determine comparability to transcranial approaches for long-term control. Large tumors with significant extension lateral to the carotid artery may not be suitable for this approach.
Raghav Gupta, Nimer Adeeb, Christoph J. Griessenauer, Justin M. Moore, Apar S. Patel, Christopher Kim, Ajith J. Thomas, and Christopher S. Ogilvy
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.
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.
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).
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.
Luis C. Ascanio, Raghav Gupta, Nimer Adeeb, Justin M. Moore, Christoph J. Griessenauer, Julie Mayeku, Yaw Tachie-Baffour, Ranjit Thomas, Abdulrahman Y. Alturki, Philip G. R. Schmalz, Christopher S. Ogilvy, and Ajith J. Thomas
Currently, there is no established standard regarding the ideal number of external ventricular drain (EVD) clamp trials performed before ventriculoperitoneal (VP) shunt insertion following nontraumatic subarachnoid hemorrhage (SAH). In this study, the authors aimed to evaluate this relationship.
A retrospective review of all patients presenting with SAH between July 2007 and December 2016 was performed. Patients with SAH who had received an EVD within the first 24 hours of hospital admission and had undergone at least 1 clamp trial prior to EVD removal were eligible for inclusion in the study. Patient demographics, clinical presentations, SAH etiologies and grades, clamp trial data, hospital lengths of stay, and functional outcomes were recorded.
One hundred fourteen patients with nontraumatic SAH complicated by posthemorrhagic hydrocephalus were included in the study. The median patient age was 57 years (range 28–90 years), with a male/female ratio of 1:1.7. A ruptured aneurysm was the underlying etiology of SAH in 79.8% of patients. A majority of patients (69.4%) had a Hunt and Hess grade III–V on admission. The median number of clamp trials performed was 2 (range 1–6). A VP shunt was required in 40.4% of patients. In those who underwent 2 and 3 clamp trials, 60% and 38.9%, respectively, did not require subsequent VP shunt placement.
Surgical placement of a VP shunt is associated with complications. Clamp trials are routinely performed before making the decision to insert a shunt. In the present study, the authors found that a significant percentage of patients passed their second and third clamp trials without requiring subsequent shunt insertion. These data support performing multiple clamp trials prior to shunt placement.
Raghav Gupta, Christopher S. Ogilvy, Justin M. Moore, Christoph J. Griessenauer, Alejandro Enriquez-Marulanda, Madeline Leadon, Nimer Adeeb, Luis Ascanio, Georgios A. Maragkos, Abhi Jain, Philip G. R. Schmalz, Abdulrahman Y. Alturki, Kimberly Kicielinski, Clemens M. Schirmer, and Ajith J. Thomas
There is currently no standardized follow-up imaging strategy for intracranial aneurysms treated with the Pipeline embolization device (PED). Here, the authors use follow-up imaging data for aneurysms treated with the PED to propose a standardizable follow-up imaging strategy.
A retrospective review of all patients who underwent treatment for ruptured or unruptured intracranial aneurysms with the PED between March 2013 and March 2017 at 2 major academic institutions in the US was performed.
A total of 218 patients underwent treatment for 259 aneurysms with the PED and had undergone at least 1 follow-up imaging session to assess aneurysm occlusion status. There were 235 (90.7%) anterior and 24 posterior (9.3%) circulation aneurysms. On Kaplan-Meier analysis, the cumulative incidences of aneurysm occlusion at 6, 12, 18, and 24 months were 38.2%, 77.8%, 84.2%, and 85.1%, respectively. No differences in the cumulative incidence of aneurysm occlusion according to aneurysm location (p = 0.39) or aneurysm size (p = 0.81) were observed. A trend toward a decreased cumulative incidence of aneurysm occlusion in patients 70 years or older was observed (p = 0.088). No instances of aneurysm rupture after PED treatment or aneurysm recurrence after occlusion were noted. Sixteen (6.2%) aneurysms were re-treated with the PED; 11 of these had imaging follow-up data available, demonstrating occlusion in 3 (27.3%).
The authors propose a follow-up imaging strategy that incorporates 12-month digital subtraction angiography and 24-month MRA for patients younger than 70 years and single-session digital subtraction angiography at 12 months in patients 70 years or older. For recurrent or persistent aneurysms, re-treatment with the PED or use of an alternative treatment modality may be considered.