While the majority of cerebral revascularization advancements were made in the last century, it is worth noting the humble beginnings of vascular surgery throughout history to appreciate its progression and application to neurovascular pathology in the modern era. Nearly 5000 years of basic human inquiry into the vasculature and its role in neurological disease has resulted in the complex neurosurgical procedures used today to save and improve lives. This paper explores the story of the extracranial-intracranial approach to cerebral revascularization.
Sauson Soldozy, John S. Costello, Pedro Norat, Jennifer D. Sokolowski, Kamron Soldozy, Min S. Park, Petr Tvrdik, and M. Yashar S. Kalani
Sauson Soldozy, Jacob Galindo, Harrison Snyder, Yusuf Ali, Pedro Norat, Kaan Yağmurlu, Jennifer D. Sokolowski, Khadijeh Sharifi, Petr Tvrdik, Min S. Park, and M. Yashar S. Kalani
Neuroimaging is an indispensable tool in the workup and management of patients with neurological disorders. Arterial spin labeling (ASL) is an imaging modality that permits the examination of blood flow and perfusion without the need for contrast injection. Noninvasive in nature, ASL provides a feasible alternative to existing vascular imaging techniques, including angiography and perfusion imaging. While promising, ASL has yet to be fully incorporated into the diagnosis and management of neurological disorders. This article presents a review of the most recent literature on ASL, with a special focus on its use in moyamoya disease, brain neoplasms, seizures, and migraines and a commentary on recent advances in ASL that make the imaging technique more attractive as a clinically useful tool.
Sauson Soldozy, Pedro Norat, Kaan Yağmurlu, Jennifer D. Sokolowski, Khadijeh A. Sharifi, Petr Tvrdik, Min S. Park, and M. Yashar S. Kalani
Arteriovenous malformation (AVM) presenting with epilepsy significantly impacts patient quality of life, and it should be considered very much a seizure disorder. Although hemorrhage prevention is the primary treatment aim of AVM surgery, seizure control should also be at the forefront of therapeutic management. Several hemodynamic and morphological characteristics of AVM have been identified to be associated with seizure presentation. This includes increased AVM flow, presence of long pial draining vein, venous outflow obstruction, and frontotemporal location, among other aspects. With the advent of high-throughput image processing and quantification methods, new radiographic attributes of AVM-related epilepsy have been identified. With respect to therapy, several treatment approaches are available, including conservative management or interventional modalities; this includes microsurgery, radiosurgery, and embolization or a combination thereof. Many studies, especially in the domain of microsurgery and radiosurgery, evaluate both techniques with respect to seizure outcomes. The advantage of microsurgery lies in superior AVM obliteration rates and swift seizure response. In addition, by incorporating electrophysiological monitoring during AVM resection, adjacent or even remote epileptogenic foci can be identified, leading to extended lesionectomy and improved seizure control. Radiosurgery, despite resulting in reduced AVM obliteration and prolonged time to seizure freedom, avoids the risks of surgery altogether and may provide seizure control through various antiepileptic mechanisms. Embolization continues to be used as an adjuvant for both microsurgery and radiosurgery. In this study, the authors review the latest imaging techniques in characterizing AVM-related epilepsy, in addition to reviewing each treatment modality.
Sauson Soldozy, Michelle Yeghyayan, Kaan Yağmurlu, Pedro Norat, Davis G. Taylor, M. Yashar S. Kalani, John A. Jane Jr., and Hasan R. Syed
The goal of this study was to systematically review the outcomes of endoscopic endonasal surgery (EES) for pediatric craniopharyngiomas so as to assess its safety and efficacy.
A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986 and 2019. All studies assessing outcomes following EES for pediatric craniopharyngiomas were included.
Of the total 48 articles identified in the original literature search, 13 studies were ultimately selected. This includes comparative studies with other surgical approaches, retrospective cohort studies, and case series.
EES for pediatric craniopharyngiomas is a safe and efficacious alternative to other surgical approaches. Achieving gross-total resection with minimal complications is feasible with EES and is comparable, if not superior in some cases, to traditional means of resection. Ideally, a randomized controlled trial might be implemented in the future to further elucidate the effectiveness of EES for resection of craniopharyngiomas.
Sauson Soldozy, Steven Young, Jeyan S. Kumar, Stepan Capek, Daniel R. Felbaum, Walter C. Jean, Min S. Park, and Hasan R. Syed
The goal of this study was to systematically review the feasibility and safety of minimally invasive neurovascular approaches to brain-machine interfaces (BMIs).
A systematic literature review was performed using the PubMed database for studies published between 1986 and 2019. All studies assessing endovascular neural interfaces were included. Additional studies were selected based on review of references of selected articles and review articles.
Of the 53 total articles identified in the original literature search, 12 studies were ultimately selected. An additional 10 articles were included from other sources, resulting in a total of 22 studies included in this systematic review. This includes primarily preclinical studies comparing endovascular electrode recordings with subdural and epidural electrodes, as well as studies evaluating stent-electrode gauge and material type. In addition, several clinical studies are also included.
Endovascular stent-electrode arrays provide a minimally invasive approach to BMIs. Stent-electrode placement has been shown to be both efficacious and safe, although further data are necessary to draw comparisons between subdural and epidural electrode measurements given the heterogeneity of the studies included. Greater access to deep-seated brain regions is now more feasible with stent-electrode arrays; however, further validation is needed in large clinical trials to optimize this neural interface. This includes the determination of ideal electrode material type, venous versus arterial approaches, the feasibility of deep brain stimulation, and more streamlined computational decoding techniques.
Mazin Elsarrag, Sauson Soldozy, Parantap Patel, Pedro Norat, Jennifer D. Sokolowski, Min S. Park, Petr Tvrdik, and M. Yashar S. Kalani
Enhanced recovery after surgery (ERAS) is a multidimensional approach to improving the care of surgical patients using subspecialty- and procedure-specific evidence-based protocols. The literature provides evidence of the benefits of ERAS implementation, which include expedited functional recovery, decreased postoperative morbidity, reduced costs, and improved subjective patient experience. Although extensively examined in other surgical areas, ERAS principles have been applied to spine surgery only in recent years. The authors examine studies investigating the application of ERAS programs to patients undergoing spine surgery.
The authors conducted a systematic review of the PubMed and MEDLINE databases up to November 20, 2018.
Twenty full-text articles were included in the qualitative analysis. The majority of studies were retrospective reviews of nonrandomized data sets or qualitative investigations lacking formal control groups; there was 1 protocol for a future randomized controlled trial. Most studies demonstrated reduced lengths of stay and no increase in rates of readmissions or complications after introduction of an ERAS pathway.
These introductory studies demonstrate the potential of ERAS protocols, when applied to spine procedures, to reduce lengths of stay, accelerate return of function, minimize postoperative pain, and save costs.
Sauson Soldozy, Pedro Norat, Mazin Elsarrag, Ajay Chatrath, John S. Costello, Jennifer D. Sokolowski, Petr Tvrdik, M. Yashar S. Kalani, and Min S. Park
The pathogenesis of intracranial aneurysms remains complex and multifactorial. While vascular, genetic, and epidemiological factors play a role, nascent aneurysm formation is believed to be induced by hemodynamic forces. Hemodynamic stresses and vascular insults lead to additional aneurysm and vessel remodeling. Advanced imaging techniques allow us to better define the roles of aneurysm and vessel morphology and hemodynamic parameters, such as wall shear stress, oscillatory shear index, and patterns of flow on aneurysm formation, growth, and rupture. While a complete understanding of the interplay between these hemodynamic variables remains elusive, the authors review the efforts that have been made over the past several decades in an attempt to elucidate the physical and biological interactions that govern aneurysm pathophysiology. Furthermore, the current clinical utility of hemodynamics in predicting aneurysm rupture is discussed.
Matthew J. Shepard, M. Harrison Snyder, Sauson Soldozy, Leonel L. Ampie, Saul F. Morales-Valero, and John A. Jane Jr.
Early surgical intervention for patients with pituitary apoplexy (PA) is thought to improve visual outcomes and decrease mortality. However, some patients may have good clinical outcomes without surgery. The authors sought to compare the radiological and clinical outcomes of patients with PA who were managed conservatively versus those who underwent early surgery.
Patients with symptomatic PA were identified. Radiological, endocrinological, and ophthalmological data were reviewed. Patients with progressive visual deterioration or ophthalmoplegia were candidates for early surgery (within 7 days). Patients without visual symptoms or whose symptoms improved on high-dose steroids were treated conservatively. Log-rank and univariate analysis compared clinical and radiological outcomes between those receiving early surgery and those who underwent intended conservative management.
Sixty-four patients with PA were identified: 47 (73.4%) underwent intended conservative management, while 17 (26.6%) had early surgery. Patients receiving early surgery had increased rates of impaired visual acuity (VA; 64.7% vs 27.7%, p = 0.009); visual field (VF) deficits (64.7% vs 19.2%, p = 0.002); and cranial neuropathies (58.8% vs 29.8%, p < 0.05) at presentation. Tumor volumes were greater in the early surgical cohort (15.1 ± 14.8 cm3 vs 4.5 ± 10.3 cm3, p < 0.001). The median clinical and radiological follow-up visits were longer in the early surgical cohort (70.0 and 64.4 months vs 26.0 and 24.7 months, respectively; p < 0.001). Among those with VA/VF deficits, visual outcomes were similar between both groups (p > 0.9). The median time to VA improvement (2.0 vs 3.0 months, p = 0.9; HR 0.9, 95% CI 0.3–3.5) and the median time to VF improvement (2.0 vs 1.5 months; HR 0.8, 95% CI 0.3–2.6, p = 0.8) were similar across both cohorts. Cranial neuropathy improvement was more common in conservatively managed patients (HR 4.8, 95% CI 1.5–15.4, p < 0.01). Conservative management failed in 7 patients (14.9%) and required surgery. PA volumes spontaneously regressed in 95.0% of patients (38/40) with successful conservative management, with a 6-month regression rate of 66.2%. Twenty-seven patients (19 in the conservative and 8 in the early surgical cohorts) responded to a prospectively administered Visual Function Questionnaire-25 (VFQ-25). VFQ-25 scores were similar across both cohorts (conservative 95.5 ± 3.8, surgery 93.2 ± 5.1, p = 0.3). Younger age, female sex, and patients with VF deficits or chiasmal compression were more likely to experience unsuccessful conservative management. Surgical outcomes were similar for patients receiving early versus delayed surgery.
These data suggest that a majority of patients with PA can be successfully managed without surgical intervention assuming close neurosurgical, radiological, and ophthalmological follow-up is available.