The contemporary management of projectile head injuries owes much to the lessons neurosurgeons have distilled from their experiences in war. Through early investigation and an increasingly detailed account of wartime clinical experience, neurosurgeons—including the field's early giants—began to gain a greater understanding not only of intracranial missile pathophysiology but also of appropriate management. In this paper, the authors trace the development of the principles of managing intracranial projectile injury from the Crimean War in the 19th century through the Vietnam War to provide a context that frames a summary of today's core management principles.
Pankaj K. Agarwalla, Gavin P. Dunn, and Edward R. Laws
Pankaj K. Agarwalla, Christopher J. Stapleton, Michael T. Phillips, Brian P. Walcott, Andrew S. Venteicher, and Christopher S. Ogilvy
Moyamoya disease/syndrome (MMD/S) is a progressive, occlusive vasculopathy of the intracranial vasculature that leads to ischemic and hemorrhagic strokes. Significant debate exists regarding the role of indirect cerebrovascular bypass surgery in its management. The authors review their institution's experience with indirect bypass in the surgical management of patients with MMD/S.
The authors conducted a retrospective review of patients with MMD/S who underwent encephaloduroarteriosynangiosis (EDAS), a form of indirect bypass, from 1996 to 2013.
A total of 37 patients (52 hemispheres) underwent an EDAS procedure for MMD/S; 21 patients received revascularization of both hemispheres. Patients presented with the following: 49% with stroke, 35% with transient ischemic attack, 13% with hemorrhage, and 3% with seizure. The mean Suzuki grade was 3.46. The number of patients with a modified Rankin Scale score of 0–1 improved from 21 to 29 (p = 0.002) from the time of surgery to the time of last follow-up. The number of neurological events (i.e., transient ischemic attacks, strokes, and hemorrhages) decreased from a mean of 1.7 events per patient to 0.14 (p < 0.001). The mean length of follow-up was 32.8 months.
This series demonstrates that EDAS is an effective procedure for MMD/S in a North American cohort of patients.
Gabriel Zada, Pankaj K. Agarwalla, Srinivasan Mukundan Jr., Ian Dunn, Alexandra J. Golby, and Edward R. Laws Jr.
A considerable degree of variability exists in the anatomy of the sphenoid sinus, sella turcica, and surrounding skull base structures. The authors aimed to characterize neuroimaging and intraoperative variations in the sagittal and coronal surgical anatomy of healthy controls and patients with sellar lesions.
Magnetic resonance imaging studies obtained in 100 healthy adults and 78 patients with sellar lesions were reviewed. The following measurements were made on midline sagittal images: sellar face, sellar prominence, sellar angle, tuberculum sellae angle, sellar-clival angle, length of planum sphenoidale, and length of clivus. The septal configuration of the sphenoid sinus was classified as either simple or complex, according to the number of septa, their symmetry, and their morphological features. The following measurements were made on coronal images: maximum width of the sphenoid sinus and sellar face, and the distance between the parasellar and midclivus internal carotid arteries. Neuroimaging results were correlated with intraoperative findings during endoscopic transsphenoidal surgery.
Three sellar floor morphologies were defined in normal adults: prominent (sellar angle of < 90°) in 25%, curved (sellar angle 90–150°) in 63%, flat (sellar angle > 150°) in 11%, and no floor (conchal sphenoid) in 1%. In healthy adults, the following mean measurements were obtained: sellar face, 13.4 mm; sellar prominence, 3.0 mm; sellar angle, 112°; angle of tuberculum sellae, 112°; and sellar-clival angle, 117°. Compared with healthy adults, patients with sellar lesions were more likely to have prominent sellar types (43% vs 25%, p = 0.01), a more acute sellar angle (102° vs 112°, p = 0.03), a more prominent sellar floor (3.8 vs 3.0 mm, p < 0.005), and more acute tuberculum (105° vs 112°, p < 0.01) and sellar-clival (105° vs 117°, p < 0.003) angles. A flat sellar floor was more difficult to identify intraoperatively and more likely to require the use of a chisel or drill to expose (75% vs 25%, p = 0.01). A simple sphenoid sinus configuration (no septa, 1 vertical septum, or 2 symmetric vertical septa) was noted in 71% of studies, and the other 29% showed a complex configuration (2 or more asymmetrical septa, 3 or more septa of any kind, or the presence of a horizontal septum). Intraoperative correlation was more challenging in cases with complex sinus anatomy; the most reliable intraoperative midline markers were the vomer, superior sphenoid rostrum, and bilateral parasellar and clival carotid protuberances.
Preoperative assessment of neuroimaging studies is critical for characterizing the morphological characteristics of the sphenoid sinus, sellar floor, tuberculum sellae, and clivus. The flat sellar type identified in 11% of people) or a complex sphenoid sinus configuration (in 29% of people) may make intraoperative correlation substantially more challenging. An understanding of the regional anatomy and its variability can improve the safety and accuracy of transsphenoidal and extended endoscopic skull base approaches.
Matthew J. Koch, Christopher J. Stapleton, Pankaj K. Agarwalla, Collin Torok, John H. Shin, Jean-Valery Coumans, Lawrence F. Borges, Christopher S. Ogilvy, James D. Rabinov, and Aman B. Patel
Vascular malformations of the spine represent rare clinical entities with profound neurological implications. Previously reported studies on management strategies for spinal dural arteriovenous fistulas (sDAVFs) appeared before the advent of modern liquid embolic agents. Authors of the present study review their institutional experience with endovascularly and surgically treated sDAVFs.
The authors performed a retrospective, observational, single-center case series on sDAVFs treated with endovascular embolization, microsurgical occlusion, or both between 2004 and 2013. The mode, efficacy, and clinical effect of treatment were evaluated.
Forty-seven patients with spinal arteriovenous malformations were evaluated using spinal angiography, which demonstrated 34 Type I sDAVFs (thoracic 20, lumbar 12, and cervical 2). Twenty-nine of the patients (85%) were male, and the median patient age was 63.3 years. Twenty patients underwent primary endovascular embolization (16 Onyx, 4 N-butyl cyanoacrylate [NBCA]), and 14 underwent primary surgical clipping. At a mean follow-up of 36 weeks, according to angiography or MR angiography, 5 patients treated with endovascular embolization demonstrated persistent arteriovenous shunting, whereas none of the surgically treated patients showed lesion persistence (p = 0.0237). Thirty patients (88%) experienced some resolution of their presenting symptoms (embolization 17 [85%], surgery 13 [93%], p = 1.00).
Microsurgical occlusion remains the most definitive treatment modality for sDAVFs, though modern endovascular techniques remain a viable option for the initial treatment of anatomically amenable lesions. Treatment of these lesions usually results in some clinical improvement.
Wenya Linda Bi, Malak Abedalthagafi, Peleg Horowitz, Pankaj K. Agarwalla, Yu Mei, Ayal A. Aizer, Ryan Brewster, Gavin P. Dunn, Ossama Al-Mefty, Brian M. Alexander, Sandro Santagata, Rameen Beroukhim, and Ian F. Dunn
Meningiomas are the most common primary intracranial neoplasms in adults. Current histopathological grading schemes do not consistently predict their natural history. Classic cytogenetic studies have disclosed a progressive course of chromosomal aberrations, especially in high-grade meningiomas. Furthermore, the recent application of unbiased next-generation sequencing approaches has implicated several novel genes whose mutations underlie a substantial percentage of meningiomas. These insights may serve to craft a molecular taxonomy for meningiomas and highlight putative therapeutic targets in a new era of rational biology-informed precision medicine.