Publications by authors named "Safavi-Abbasi S"

Understanding the sequence of cellular responses and their contributions to pathomorphogical changes in spinal white matter injuries is a prerequisite for developing efficient therapeutic strategies for spinal cord injury (SCI) as well as neurodegenerative and inflammatory diseases of the spinal cord such as amyotrophic lateral sclerosis and multiple sclerosis. We have developed several types of surgical procedures suitable for acute one-time and chronic recurrent in vivo multiphoton microscopy of spinal white matter [1]. Sophisticated surgical procedures were combined with transgenic mouse technology to image spinal tissue labeled with up to four fluorescent proteins (FPs) in axons, astrocytes, microglia, and blood vessels.

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Objective: Because the clinical course of spontaneous aneurysmal subarachnoid hemorrhage (aSAH) can be compromised by pulmonary complications, we sought to review posttreatment outcomes in aSAH patients with and without pulmonary complications.

Methods: Patient demographic, clinical, and outcome data (March 2003-January 2007) were analyzed retrospectively. Patients underwent microsurgical or endovascular treatment for aSAH; pulmonary complications were reported.

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Background: Moderate to severe traumatic brain injury confers increased risk of posttraumatic seizures (PTSs). Early PTSs are diagnosed when seizures develop within 7 days after injury, whereas seizures diagnosed as late PTSs occur later. Patients have been treated with phenytoin (PHT) to prevent early PTSs and more recently with levetiracetam (LEV).

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OBJECTIVE The best approach to deep-seated lateral and third ventricle lesions is a function of lesion characteristics, location, and relationship to the ventricles. The authors sought to examine and compare angles of attack and surgical freedom of anterior ipsilateral and contralateral interhemispheric transcallosal approaches to the frontal horn of the lateral ventricle using human cadaveric head dissections. Illustrative clinical experiences with a contralateral interhemispheric transcallosal approach and an anterior interhemispheric transcallosal transchoroidal approach are also related.

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We developed appropriate surgical procedures for single and repetitive multi-photon imaging of spinal cord in vivo. By intravenous anesthesia, artificial ventilation and laminectomy, acute experiments were performed in the dorsal and lateral white matter. By volatile anesthesia and minimal-invasive surgery, chronic repetitive imaging up to 8 months were performed in the dorsal column through the window between two adjacent spines.

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OBJECTIVE Fusiform cerebral aneurysms represent a small portion of intracranial aneurysms; differ in natural history, anatomy, and pathology; and can be difficult to treat compared with saccular aneurysms. The purpose of this study was to examine the techniques of treatment of ruptured and unruptured fusiform intracranial aneurysms and patient outcomes. METHODS In 45 patients with fusiform aneurysms, the authors retrospectively reviewed the presentation, location, and shape of the aneurysm; the microsurgical technique; the outcome at discharge and last follow-up; and the change in the aneurysm at last angiographic follow-up.

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Objective: To define the maxillary artery (MaxA) anatomy and present a novel technique for exposing and preparing this vessel as a bypass donor.

Methods: Cadaveric and radiologic studies were used to define the MaxA anatomy and show a novel method for harvesting and preparing it for extracranial to intracranial bypass.

Results: The MaxA runs parallel to the frontal branch of the superficial temporal artery and is located on average 24.

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OBJECTIVE The aim of this investigation was to modify the mini-pterional and mini-orbitozygomatic (mini-OZ) approaches in order to reduce the amount of tissue traumatization caused and to compare the use of the 2 approaches in the removal of circle of Willis aneurysms based on the authors' clinical experience and quantitative analysis. METHODS Three formalin-fixed adult cadaveric heads injected with colored silicone were examined. Surgical freedom and angle of attack of the mini-pterional and mini-OZ approaches were measured at 9 anatomical points, and the measurements were compared.

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Objectives/hypothesis: Image-guided optical tracking systems are being used with increased frequency in lateral skull base surgery. Recently, electromagnetic tracking systems have become available for use in this region. However, the clinical accuracy of the electromagnetic tracking system has not been examined in lateral skull base surgery.

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Background: Keyhole craniotomies are increasingly being used for lesions of the skull base. Here we review our recent experience with these approaches for resection of intracranial meningiomas.

Methods: Clinical and operative data were gathered on all patients treated with keyhole approaches by the senior author from January 2012 to June 2013.

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Background: Surgical revascularization for adults with moyamoya disease (MD) includes direct, indirect, or combination bypasses. It is unclear which provides the best outcomes. We sought to determine the best surgical management for adults with MD by comparing perioperative complications and long-term outcomes among 3 bypass types.

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OBJECTIVE Aneurysmal subarachnoid hemorrhage (aSAH) may be complicated by hydrocephalus in 6.5%-67% of cases. Some patients with aSAH develop shunt dependency, which is often managed by ventriculoperitoneal shunt placement.

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An understanding of the underlying pathophysiology of tethered cord syndrome (TCS) and modern management strategies have only developed within the past few decades. Current understanding of this entity first began with the understanding and management of spina bifida; this later led to the gradual recognition of spina bifida occulta and the symptoms associated with tethering of the filum terminale. In the 17th century, Dutch anatomists provided the first descriptions and initiated surgical management efforts for spina bifida.

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Objective: Some aneurysms without a definable neck and associated parent vessel pathology are particularly difficult to treat and may require clipping with circumferential wrapping. We report the largest available contemporary series examining the techniques of Gore-Tex clip-wrapping of ruptured and unruptured intracranial aneurysms and patient outcomes.

Methods: The presentation, location, and shape of the aneurysm; wrapping technique; outcome at discharge and last follow-up; and any change in the aneurysm at last angiographic follow-up were reviewed retrospectively in 30 patients with Gore-Tex clip-wrapped aneurysms.

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Microsurgical clipping of intracranial aneurysms often requires access to the subarachnoid space deep in the brain. In the past, fixed retractors have been used to maintain the surgical corridor. However, studies have shown that fixed retraction leads to brain injuries.

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OBJECTIVE Microvascular anastomosis is a basic neurosurgical technique that should be mastered in the laboratory. Human and bovine placentas have been proposed as convenient surgical practice models; however, the histologic characteristics of these tissues have not been compared with human cerebral vessels, and the models have not been validated as simulation training models. In this study, the authors assessed the construct, face, and content validities of microvascular bypass simulation models that used human and bovine placental vessels.

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OBJECTIVE To address the challenges of microsurgically treating broad-based, frail, and otherwise complex aneurysms that are not amenable to direct clipping, alternative techniques have been developed. One such technique is to use cotton to augment clipping ("cotton-clipping" technique), which is also used to manage intraoperative aneurysm neck rupture, and another is to reinforce unclippable segments or remnants of aneurysm necks with cotton ("cotton-augmentation" technique). This study reviews the natural history of patients with aneurysms treated with cotton-clipping and cotton-augmentation techniques.

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OBJECT The coexistence of Chiari malformation Type I (CM-I) and ventral brainstem compression (VBSC) has been well documented, but the change in VBSC after posterior fossa decompression (PFD) has undergone little investigation. In this study the authors evaluated VBSC in patients with CM-I and determined the change in VBSC after PFD, correlating changes in VBSC with clinical status and the need for further intervention. METHODS Patients who underwent PFD for CM-I by the senior author from November 2005 to January 2013 with complete radiological records were included in the analysis.

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OBJECT The objective of this study was to describe the surgical anatomy and technical nuances of various vascularized tissue flaps. METHODS The surgical anatomy of various tissue flaps and their vascular pedicles was studied in 5 colored silicone-injected anatomical specimens. Medical records were reviewed of 11 consecutive patients who underwent repair of extensive skull base defects with a combination of various vascularized flaps.

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Microsurgical clipping of intracranial aneurysms often requires access to the subarachnoid space deep in the brain. In the past, fixed retractors have been used to maintain the surgical corridor. However, studies have shown that fixed retraction leads to brain injuries.

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Ventricular shunt failures and subsequent revisions are a significant source of patient morbidity. We conducted a review of pediatric patients undergoing placement or revision of ventricular shunts at our institution between January 2007 and December 2008. Patients were followed through to July 2014.

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Objective: This article introduces a classification scheme for extensive traumatic anterior skull base fracture to help stratify surgical treatment options. The authors describe their multilayer repair technique for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture using a combination of laterally pediculated temporalis fascial-pericranial, nasoseptal-pericranial, and anterior pericranial flaps.

Methods: Retrospective chart review identified patients treated surgically between January 2004 and May 2014 for anterior skull base fractures with CSF fistulas.

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OBJECT The Universal Clamp Spinal Fixation System (UC) is a novel sublaminar connection for the spine that is currently used in conjunction with pedicle screws at the thoracic levels for the correction of scoliosis. This device allows the surgeon to attach rods and incorporate a pedicle screw construction. The flexible composition of the UC should provide flexibility intermediate to the uninstrumented spine and an all-screw construct.

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We discuss the association between tethered cord syndrome (TCS) and Chiari type 1 malformation (CM1), and report on the surgical outcomes of children with CM1 and TCS who underwent sectioning of the filum terminale (SFT). The relationship between TCS and CM1 is unclear. A retrospective review of 170 consecutive spinal cord detetherings between 2008 and 2012 was performed.

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The authors demonstrate the utility of portable intraoperative CT scans for the rapid identification of ventricular catheter tip location after Ommaya reservoir placement. The O-arm (Medtronic Sofamor Danek, Memphis, TN, USA) was utilized to confirm ventricular catheter placement intraoperatively. Conventionally, a postoperative CT scan is obtained prior to Ommaya reservoir use to ensure proper catheter placement.

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