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Dive into the research topics where Andrew C. Vivas is active.

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Featured researches published by Andrew C. Vivas.


The Scientific World Journal | 2012

The Effect of the Retroperitoneal Transpsoas Minimally Invasive Lateral Interbody Fusion on Segmental and Regional Lumbar Lordosis

Tien V. Le; Andrew C. Vivas; Elias Dakwar; Ali A. Baaj; Juan S. Uribe

Background. The minimally invasive lateral interbody fusion (MIS LIF) in the lumbar spine can correct coronal Cobb angles, but the effect on sagittal plane correction is unclear. Methods. A retrospective review of thirty-five patients with lumbar degenerative disease who underwent MIS LIF without supplemental posterior instrumentation was undertaken to study the radiographic effect on the restoration of segmental and regional lumbar lordosis using the Cobb angles on pre- and postoperative radiographs. Mean disc height changes were also measured. Results. The mean follow-up period was 13.3 months. Fifty total levels were fused with a mean of 1.42 levels fused per patient. Mean segmental Cobb angle increased from 11.10° to 13.61° (P < 0.001) or 22.6%. L2-3 had the greatest proportional increase in segmental lordosis. Mean regional Cobb angle increased from 52.47° to 53.45° (P = 0.392). Mean disc height increased from 6.50 mm to 10.04 mm (P < 0.001) or 54.5%. Conclusions. The MIS LIF improves segmental lordosis and disc height in the lumbar spine but not regional lumbar lordosis. Anterior longitudinal ligament sectioning and/or the addition of a more lordotic implant may be necessary in cases where significant increases in regional lumbar lordosis are desired.


Neurosurgical Focus | 2012

The health care burden of patients with epilepsy in the United States: An analysis of a nationwide database over 15 years

Andrew C. Vivas; Ali A. Baaj; Selim R. Benbadis; Fernando L. Vale

OBJECT The aim of this study was to analyze the national health care burden of patients diagnosed with epilepsy in the US and to analyze any changes in the length of stay, mean charges, in-hospital deaths (mortality), and disposition at discharge. METHODS A retrospective review of the Nationwide Inpatient Sample (NIS) database for epilepsy admissions was completed for the years from 1993 to 2008. The NIS is maintained by the Agency for Healthcare Research and Quality and represents a 20% random stratified sample of all discharges from nonfederal hospitals within the U.S. Patients with epilepsy were identified using ICD-9 codes beginning with 345.XX. Approximately 1.1 million hospital admissions were identified over a span of 15 years. RESULTS Over this 15-year period (between 1993 and 2008), the average hospital charge per admission for patients with epilepsy has increased significantly (p < 0.001) from


Journal of Clinical Neuroscience | 2017

MRI-guided laser interstitial thermal therapy for treatment of medically refractory non-lesional mesial temporal lobe epilepsy: Outcomes, complications, and current limitations: A review

Hena Waseem; Andrew C. Vivas; Fernando L. Vale

10,050 to


Journal of Spinal Disorders & Techniques | 2014

Optimal trajectory for the occipital condyle screw

Tien V. Le; Andrew C. Vivas; Ali A. Baaj; Fernando L. Vale; Juan S. Uribe

23,909, an increase of 137.9%. This is in spite of a 33% decrease in average length of stay from 5.9 days to 3.9 days. There has been a decrease in the percentage of in-hospital deaths by 57.9% and an increase in discharge to outside medical institutions. CONCLUSIONS The total national charges associated with epilepsy in 2008 were in excess of


Journal of Neurosurgery | 2017

Effects of intradiscal vacuum phenomenon on surgical outcome of lateral interbody fusion for degenerative lumbar disease.

Chun-Po Yen; Joshua M. Beckman; Andrew C. Vivas; Konrad Bach; Juan S. Uribe

2.7 billion (U.S. dollars, normalized). During the studied period, the cost per day for patients rose from


Journal of Clinical Neuroscience | 2017

Indirect decompression and reduction of lumbar spondylolisthesis does not result in higher rates of immediate and long term complications

Jacob Januszewski; Joshua M. Beckman; Konrad Bach; Andrew C. Vivas; Juan S. Uribe

1703.39 to


Epilepsy & Behavior | 2017

An analysis of quality of life (QOL) in patients with epilepsy and comorbid psychogenic nonepileptic seizures (PNES) after vagus nerve stimulation (VNS)

Andrew C. Vivas; Christian J. Reitano; Hena Waseem; Selim R. Benbadis; Fernando L. Vale

6130.51. In spite of this drastic increase in health care cost to the patient, medical and surgical treatment for epilepsy has not changed significantly, and epilepsy remains a major source of morbidity.


Operative Neurosurgery | 2018

Incisional Hernia After Minimally Invasive Lateral Retroperitoneal Surgery: Case Series and Review of the Literature

Andrew C. Vivas; Jacob Januszewski; Luv Hajirawala; Jason Paluzzi; Shashank V Gandhi; Juan S. Uribe

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. We evaluated a number of outcome measures, including seizure freedom, neuropsychological performance, complications, and other considerations. Eighteen (53%) had an Engel class I outcome, 10 patients had repeat procedures/operations, and 12 post-procedural complications occurred. Follow-up time ranged from 6 to 38.5months. There was a decreased length of procedure time, hospitalization time, and analgesic requirement when compared to open surgery. In cases of well-localized MTLE this procedure may offer similar (albeit slightly lower) rates of seizure freedom versus traditional surgery. MRgLITT may be an alternative treatment option for high risk surgical patients and, more importantly, could increase referrals for surgery in patients with medically refractory MTLE. However, data is limited and long-term outcomes have not been evaluated. Further investigation is required to understand the potential of this minimally invasive technique for MTLE.


Epilepsia Open | 2018

Wada asymmetry in patients with drug-resistant mesial temporal lobe epilepsy: Implications for postoperative neuropsychological outcomes

Ryan W. Sever; Andrew C. Vivas; Fernando L. Vale; Mike R. Schoenberg

Study Design: Retrospective analysis. Objective: To understand what may constitute an optimal trajectory for an occipital condyle (OC) screw. Summary of Background Data: OC screws are an alternative to standard occipital plates as a cephalad fixation point in occipitocervical fusion. An optimal trajectory for placement of OC screws has not been described. Methods: We conducted a computed tomography-based study of 340 human occipital condyls. All computed tomographies were negative for traumatic, degenerative, and neoplastic pathology. On the basis of the current literature, linear measurements of distances were made based on a constant entry point. Medial angulations of 10, 20, and 25 degrees relative to the sagittal midline were used. In addition, 10-, 5-degree cranial, 10- and 30-degree caudal angulations were studied to evaluate the incidence of hypoglossal canal and atlantooccipital joint compromise. Results: Average distances were 17.1±2.8, 20.4±2.8, and 22.2±2.9 for 10, 20, and 25 degrees of medial angulation, respectively. Right-sided and left-sided measurements for each category were not significantly different. However, the difference in the measured distances between 10 versus 20 degrees, 10 versus 25 degrees, and 20 versus 25 degrees was all significantly different (P<0.01). Hypoglossal canal compromise incidence was 0% and 7.1% for 5- and 10-degree cranial angulation, respectively. Atlantooccipital joint compromise incidence was 21.8% and 99.1% for 10- and 30-degree caudal angulation, respectively. Conclusions: The condylar entry point should be medial to the condylar fossa, midcondylar, and ≥2 mm caudal to the skull base. An optimal trajectory for the OC screw should have a medial angulation of ≥20 degrees relative to the sagittal midline, trying to stay parallel to the skull base. Minor adjustments in angulation can be made, but any adjustment approaching 10 degrees cranial or caudal leads to an increased risk of hypoglossal canal cranially or atlantooccipital joint compromise caudally.


ACG Case Reports Journal | 2017

Acute Shunt Failure Due to Perforation of Ventriculoperitoneal Shunt Tubing during Percutaneous Gastrostomy

Andrew C. Vivas; Michael Wilsey; Joseph K. Potthast; Gerald F. Tuite

OBJECTIVE The authors investigated whether the presence of intradiscal vacuum phenomenon (IVP) results in greater correction of disc height and restoration of segmental lordosis (SL). METHODS A retrospective chart review was performed on every patient at the University of South Floridas Department of Neurosurgery treated with lateral lumbar interbody fusion between 2011 and 2015. From these charts, preoperative plain radiographs and CT images were reviewed for the presence of IVP. Preoperative and postoperative posterior disc height (PDH), anterior disc height (ADH), and SL were measured at disc levels with IVP and compared with those at disc levels without IVP using the t-test. Linear regression was used to evaluate the factors that predict changes in PDH, ADH, and SL. RESULTS One hundred forty patients with 247 disc levels between L-1 and L-5 were treated with lateral lumbar interbody fusion. Among all disc levels treated, the mean PDH increased from 3.69 to 6.66 mm (p = 0.011), the mean ADH increased from 5.45 to 11.53 mm (p < 0.001), and the mean SL increased from 9.59° to 14.55° (p < 0.001). Significantly increased PDH was associated with the presence of IVP, addition of pedicle screws, and lack of cage subsidence; significantly increased ADH was associated with the presence of IVP, anterior longitudinal ligament (ALL) release, addition of pedicle screws, and lack of subsidence; and significantly increased SL was associated with the presence of IVP and ALL release. CONCLUSIONS IVP in patients with degenerative spinal disease remains grossly underreported. The data from the present study suggest that the presence of IVP results in increased restoration of disc height and SL.

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Juan S. Uribe

University of South Florida

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Fernando L. Vale

University of South Florida

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Jacob Januszewski

University of South Florida

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Konrad Bach

University of South Florida

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Jason Paluzzi

University of South Florida

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Selim R. Benbadis

University of South Florida

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Ali A. Baaj

Johns Hopkins University

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Amer F. Samdani

Shriners Hospitals for Children

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Chun-Po Yen

University of South Florida

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Hena Waseem

University of South Florida

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