Publications by authors named "Andrew C Vivas"

Back pain is one of the most common aversive sensations in human experience. Pain is not limited to the sensory transduction of tissue damage; rather, it encompasses a range of nervous system activities including lateral modulation, long-distance transmission, encoding, and decoding. Although spine surgery may address peripheral pain generators directly, aberrant signals along canonical aversive pathways and maladaptive influence of affective and cognitive states can result in persistent subjective pain refractory to classical surgical intervention.

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Background: Gliosarcoma is a rare and highly malignant cancer of the central nervous system with the ability to metastasize. Secondary gliosarcoma, or the evolution of a spindle cell-predominant tumor after the diagnosis of a World Health Organization grade IV glioblastoma, has also been shown to metastasize. There is little information on metastatic secondary gliosarcoma.

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Purpose: Esthesioneuroblastoma (ENB) is a rare malignant neoplasm of the olfactory epithelium with an estimated incidence of 0.4/million. It can directly extend along the cribriform plate in order to metastasize to the central nervous system.

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Background: Best practice guidelines for treating lumbar stenosis include a multidisciplinary approach, ranging from conservative management with physical therapy, medication, and epidural steroid injections to surgical decompression with or without instrumentation. Marketed as an outpatient alternative to a traditional lumbar decompression, interspinous process devices (IPDs) have gained popularity as a minimally invasive stabilization procedure. IPDs have been embraced by non-surgical providers, including physiatrists and anesthesia interventional pain specialists.

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Background: Generally, most spine surgeons agree that increased segmental motion viewed on flexion-extension radiographs is a reliable predictor of instability; however, these views can be limited in several ways and may underestimate the instability at a given lumbar segment.

Methods: Consecutively collected adult (≥18 years old) patients with symptomatic single-level lumbar spondylolisthesis were reviewed from a two-surgeon database from 2015 to 2019. Routine standing lumbar X-rays (neutral, flexion, extension) and supine lumbar MRI (sagittal T2-weighted imaging sequence) were performed.

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The advantages of anterior, muscle-sparing interbody fusion for the management of degenerative scoliosis have been well defined in the literature. These include both direct and indirect decompression, restoration of disk/foraminal height and spinal biomechanics, correction of sagittal balance, and improved fusion rates. The continued evolution of minimally invasive techniques and surgical instrumentation has led to reduced morbidity for patients and increased popularity for anterior interbody techniques among surgeons.

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Study Design: This was a post hoc analysis of a prospective FDA-IDE study.

Objective: The purpose of this study is to determine the effectiveness of a 2-level anterior cervical discectomy and fusion (ACDF) or cervical disk arthroplasty (CDA) at relieving headaches associated with cervical radiculopathy or myelopathy at 10 years postoperative.

Background: To our knowledge, there is no large, prospective study that has examined the efficacy of cervical spine surgery for relieving headaches associated with radiculopathy or myelopathy at 10 years postoperative.

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Introduction: Implant subsidence is a potential complication of spinal interbody fusion and may negatively affect patients subjected to procedures relying on indirect decompression such as minimally invasive transpsoas lateral lumbar interbody fusion (LLIF). The porous architecture of a recently developed titanium intervertebral cage maximizes bone-to-implant contact and minimizes stress shielding in laboratory experiments; however, its subsidence rate in patients has not yet been evaluated. The goal of this current study was to evaluate implant subsidence in patients subjected to LLIF.

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Study Design: Retrospective review of a prospectively collected multicenter registry of pediatric patients with cerebral palsy (CP) and neuromuscular scoliosis (NMS) undergoing spinal fusion.

Objective: To define risk factors for unplanned readmission after elective spinal deformity surgery. Patients with CP and NMS have high rates of hospital readmission; however, risk factors for readmission are not well established.

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Background: Patients with a lesion within the amygdala and uncus may develop temporal lobe epilepsy despite having functional mesial structures. Resection of functional hippocampus and surrounding structures may lead to unacceptable iatrogenic deficits. To our knowledge, there is limited descriptions of surgical techniques for selectively resecting the amygdala and uncus lesions while preserving the hippocampus in patients with language-dominant temporal lobe pathology.

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Objective: This study reports neuropsychological outcomes based on preoperative Wada testing in patients with drug-resistant mesial temporal lobe epilepsy (mTLE).

Methods: Patient records were retrospectively reviewed as part of a larger database. Patients with a diagnosis of TLE based on seizure semiology and long-term surface video-electroencephalography (EEG) were identified.

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Objective: Hydrocephalus associated with subdural hygromas is a rare complication after decompression of Chiari malformation type I (CM-I). There is no consensus for management of this complication. The authors present a series of 5 pediatric patients who underwent CM-I decompression with placement of a dural graft complicated by posterior fossa hygromas and hydrocephalus that were successfully managed nonoperatively.

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Background: Reported complication rates for minimally invasive lateral transpsoas interbody fusion (MIS-LIF) vary widely. The risk of lumbar plexus injury is particularly concerning at the L4-5 disc space. We report our experience with MIS-LIF at L4-5, and discuss the risk profile of transpsoas approaches at this level.

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Background: Minimally invasive lateral retroperitoneal (lateral-MIS) approaches to the spine involve traversing the lateral abdominal wall musculature and fascia. Incisional hernia is an uncommon approach-related complication.

Objective: To review the incidence, treatment, and preventative measures of incisional hernia after lateral-MIS approaches.

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Minimally invasive spine (MIS) surgery has rapidly progressed from simple short segment fusions to large adult deformity corrections, with radiographic and clinical outcomes as good as those of open surgery. Anterior longitudinal ligament release (ALLR) and anterior column realignment (ACR) have been key advancements in the ability to correct deformity using MIS techniques. However, patient selection and appropriate preoperative workup is critical to obtain good outcomes and for complication avoidance.

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Study Design: A retrospective review of a prospectively collected multicenter database.

Objective: To assess the effect of proximal hooks versus screws on proximal junctional kyphosis (PJK) as well as shoulder balance in otherwise all pedicle screw (>80%) posterior spinal fusion (PSF) constructs in adolescent idiopathic scoliosis (AIS).

Summary Of Background Data: Less rigid forms of fixation at the top of constructs in degenerative lumbar PSF have been postulated to decrease the risk of PJK.

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Background: Development of proximal junctional kyphosis (PJK) after correction of adult spinal deformity (ASD) undermines sagittal alignment. Minimally invasive anterior column realignment (ACR) is a powerful tool for correction of ASD; however, long-term PJK rates are unknown.

Objective: To characterize PJK after utilization of ACR in ASD correction.

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Phrenic stimulators offer an alternative to standard mechanical ventilation as well as the potential for ventilator independence in select patients with chronic respiratory failure. Young patients (< 10 years old) with high cervical spinal cord injuries often develop paralytic scoliosis due to loss of muscle tone caudal to their spinal cord lesion. Growing rod systems allow for stabilization of spinal deformity while permitting continued growth of the spine and thoracic cavity.

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Nerve root decompression and spondylolisthesis reduction is typically reserved for open surgery. MIS techniques have been thought to be associated with higher rates of neurological complications. This study aims to report acute and chronic neurologic complications encountered with MIS surgery for spondylolisthesis, specifically, the incidence of nerve root injury and clinical and radiographic outcomes.

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Purpose: Patients with epilepsy (PWE) may suffer from comorbid psychogenic nonepileptic seizures (PNES). The efficacy of vagus nerve stimulation (VNS) in the treatment of epilepsy and depression is established, however the impact on PNES is unknown. Since many patients with PNES have comorbid depression, we explored the impact on quality of life (QOL) that VNS has on PWE and PNES.

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The placement of a percutaneous endoscopic gastrostomy (PEG) in a patient with a pre-existing ventriculoperitoneal shunt is generally regarded as safe. A critical but often overlooked technical consideration is confirmation of the course of the distal shunt tube prior to PEG insertion. We present the case of a 4-month-old male infant with shunted hydrocephalus who experienced shunt malfunction due to perforation of the distal shunt tubing after PEG placement.

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Injury to the lumbosacral (LS) plexus is a well-described complication after lateral retroperitoneal transpsoas approaches to the spine. The prognosis for functional recovery after lumbosacral plexopathy or femoral/obturator neuropathy is unclear. We designed a retrospective case-control study with patients undergoing one-level lateral retroperitoneal transpsoas lumbar interbody fusion (LLIF) between January 2011 and June 2016 to correlate electrodiagnostic assessments (EDX) to physiologic concepts of nerve injury and reinnervation, and attempt to build a timeline for patient evaluation and recovery.

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There is a new focus on minimally invasive treatments for medically refractory mesial temporal lobe epilepsy (MTLE). MRI-guided laser interstitial thermal therapy (MRgLITT) is one such minimally invasive procedure, which utilizes MRI guidance and real-time feedback to ablate an epileptogenic focus. A total of 38 patients presenting exclusively with MTLE and no other lesions (including neoplasia), who underwent MRgLITT were reviewed.

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