Publications by authors named "Leonardo B Brasiliense"

Background: Spinal hematomas are a rare entity with broad etiologies, which stem from idiopathic, tumor-related, and vascular malformation etiologies. Less common causes include traumatic blunt nonpenetrating spinal hematomas with very few cases being reported. In the present manuscript presents a case report and review of the literature of a rare traumatic entity of a cervical subarachnoid hematoma in association with Brown-Séquard syndrome in a patient on anticoagulants.

View Article and Find Full Text PDF

Introduction: Wide-necked intracranial aneurysms (IAs) are complex lesions that may require different microsurgical or endovascular strategies, and stent-assisted coiling (SAC) has emerged as a feasible alternative to treat this subset of aneurysms.

Methods: The objective was to assess the rate of complications of unruptured wide-necked IAs treated with SAC. We retrospectively identified patients with unruptured wide-necked IAs treated with SAC.

View Article and Find Full Text PDF

Flow diversion has revolutionised the treatment of intracranial aneurysms, and the Pipeline Embolization Device (PED) remains the only flow diverter (FD) approved in the USA. However, thromboembolic events remain an issue for FDs. Attempting to minimise these incidents, a newer PED has been developed with the use of covalent bonding of phosphorylcholine onto the Pipeline device that has been known as Shield Technology (PED Shield), which in vitro has demonstrated a significant reduction in material thrombogenicity.

View Article and Find Full Text PDF

Cavernous malformations are uncommon vascular lesions with an estimated prevalence of 0.5% in the general population. Intramedullary cavernous malformations (ICM) represent a rare subset of lesions, which account for approximately 5% of all cavernous malformations.

View Article and Find Full Text PDF

Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are extremely rare tumors that are frequently misdiagnosed and overlooked by clinicians. To date, only 40 intracranial lesions have been reported, and in all instances, they were found as a solitary calcified mass. To our knowledge, the current case report is the first to illustrate the development of multiple intraaxial CAPNONs and shed more light on the origin of these lesions.

View Article and Find Full Text PDF

Refinements in endovascular technology have revolutionized the treatment of intracranial aneurysms (IAs) with the development of flow-diversion technology. The first generation of the Pipelin Embolization Device (PED) has demonstrated its safety and efficacy. However, the deployment technique was a difficult task that often led to complex maneuvers.

View Article and Find Full Text PDF

Background: The development of ischemic events is relatively common after endovascular interventions, and flow diverters may pose a particular threat owing to their increased technical complexity and high metal content.

Objective: To investigate the incidence and potential risk factors for thromboembolic lesions after treatment with a Pipeline embolization device (PED).

Methods: This prospective study included a total of 59 patients electively treated with a PED over 12 months.

View Article and Find Full Text PDF

Background: Wide-necked anterior communicating artery aneurysms represent a subset of lesions with challenging endovascular treatment despite new endoluminal and intrasaccular devices.

Objective: To assess the long-term clinical and angiographic outcomes of stent-assisted embolization for wide-necked anterior communicating artery aneurysms.

Methods: Between March 2008 and March 2014, 32 patients with unruptured wide-necked AComm aneurysms were treated using stent-assisted embolization.

View Article and Find Full Text PDF

Objective: The authors sought to determine whether flow diversion with the Pipeline Embolization Device (PED) can approximate microsurgical decompression in restoring function after cranial neuropathy following carotid artery aneurysms.

Methods: This multiinstitutional retrospective study involved 45 patients treated with PED across the United States. All patients included presented between November 2009 and October 2013 with cranial neuropathy (cranial nerves [CNs] II, III, IV, and VI) due to intracranial aneurysm.

View Article and Find Full Text PDF

Revascularization of the extracranial vertebral artery has evolved significantly since the adoption of endovascular techniques. The current neurosurgical armamentarium includes microsurgical and endovascular approaches. The indications for each treatment modality, however, still need to be further delineated.

View Article and Find Full Text PDF

Many endovascular techniques have been described in recent years for the management of wide necked aneurysms. The Y stent assisted technique has been generally used for coil embolization of wide necked bifurcation aneurysms. This technique was first described for the treatment of basilar tip aneurysms in combination with several different devices, demonstrating encouraging results.

View Article and Find Full Text PDF

Background: Transitioning from rigid to flexible hardware at the distal rostral or caudal lumbar or lumbosacral level hypothetically maintains motion at the transition level and protects the transition level and intact adjacent levels from stresses caused by fusion.

Objective: To biomechanically compare transitional and rigid constructs with uninstrumented specimens in vitro.

Methods: Human cadaveric L2-S1 segments were tested (1) intact, (2) after L5-S1 rigid pedicle screw-rod fixation, (3) after L4-S1 rigid pedicle screw-rod fixation, and (4) after hybrid fixation rigidly spanning L5-S1 and dynamically spanning L4-L5.

View Article and Find Full Text PDF

Background Context: Novel dual-threaded screws are configured with overlapping (doubled) threads only in the proximal shaft to improve proximal cortical fixation.

Purpose: Tests were run to determine whether dual-threaded pedicle screws improve pullout resistance and increase fatigue endurance compared with standard pedicle screws.

Study Design/setting: In vitro strength and fatigue tests were performed in human cadaveric vertebrae and in polyurethane foam test blocks.

View Article and Find Full Text PDF

Study Design: In vitro assessment of rib cage biomechanics in the region of true ribs with the ribs intact then sequentially resected in 5 steps.

Objective: To determine the contribution of the rib cage to thoracic spine stability and kinematics.

Summary Of Background Data: Previous in vitro studies of rib cage biomechanics have used animal spines or human cadaveric spines with ribs left unsecured, limiting the ability of the ribs to contribute to stability.

View Article and Find Full Text PDF

Background Context: Most one-level anterior cervical plates use two screws per vertebra (four screws in total). No study has addressed whether a simplified plate using one screw per vertebra is adequate for one-level fixation.

Purpose: To compare stability achieved by four-screw and two-screw plates after discectomy and placement of interbody spacer.

View Article and Find Full Text PDF

Object: Posterior screw-rod fixation for thoracic spine trauma usually involves fusion across long segments. Biomechanical data on screw-based short-segment fixation for thoracic fusion are lacking. The authors compared the effects of spanning short and long segments in the thoracic spine.

View Article and Find Full Text PDF

Background: Anatomically and biomechanically, the atlantoaxial joint is unique compared with the remainder of the cervical spine.

Objective: To assess the in vitro stability provided by 2 C2 screw sparing techniques in a destabilized model of the atlantoaxial joint and compare with the gold standard system.

Methods: The 3-dimensional intervertebral motion of 7 human cadaveric cervical spine specimens was recorded stereophotogrammetrically while applying nonconstraining, nondestructive pure moments during flexion-extension, left and right axial rotation, and left and right lateral bending.

View Article and Find Full Text PDF

Hephaestus is best known as the Greek god of metalworking, fire, and fine arts. As the only Olympian deity not endowed with physical perfection, he has been considered misfortunate among the Olympians. However, textual analysis of his myths reveals that Hephaestus was highly regarded by Greeks for his manual skills and intelligence.

View Article and Find Full Text PDF

Object: The authors investigated the biomechanical properties of transpedicular discectomy in the thoracic spine and compared the effects on spinal stability of a partial and total facetectomy.

Methods: Human thoracic specimens were tested while intact, after a transpedicular discectomy with partial facetectomy, and after an additional total facetectomy was incorporated. Nonconstraining pure moments were applied under load control (maximum 7.

View Article and Find Full Text PDF

Object: The object of this study was to investigate the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of thoracic pedicle screws.

Methods: Forty human thoracic vertebrae (T6-11) from human cadavers were studied. Before pedicle screws were inserted, the specimens were separated into 4 groups according to the type of screw used: 1) standard pedicle screw (no cortical perforation); 2) screw with medial cortical perforation; 3) screw with lateral cortical perforation; and 4) "airball" screw (a screw that completely missed the vertebral body).

View Article and Find Full Text PDF

Objective: The aim of this study was to describe quantitatively the properties of the posterolateral approaches and their combination.

Methods: Six silicone-injected cadaveric heads were dissected bilaterally. Quantitative data were generated with the Optotrak 3020 system (Northern Digital, Waterloo, Canada) and Surgiscope (Elekta Instruments, Inc.

View Article and Find Full Text PDF

Objective: To compare the biomechanics of costotransverse process screw fixation with those of pedicle screw fixation in a cadaveric model of the upper thoracic spine.

Methods: Ten human thoracic spines were instrumented across the T3-T4 segment with costotransverse and pedicle screws. Nonconstraining pure moments (maximum, 6.

View Article and Find Full Text PDF

Objective: To study the alteration to normal biomechanics after insertion of a lumbar interspinous spacer (ISS) in vitro by nondestructive cadaveric flexibility testing.

Methods: Seven human cadaveric specimens were studied before and after ISS placement at L1-L2. Angular range of motion, lax zone, stiff zone, sagittal instantaneous axis of rotation (IAR), foraminal height, and facet loads were compared between conditions.

View Article and Find Full Text PDF