Marissa D'Souza

Dr. Marissa D'Souza

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2019 in Robotic Surgery: Research and Reviews
Verified
Journal Article
Open access
PDF file
MDMarissa D'Souza
Marissa D'Souza
Julian Lassiter GendreauJulian Lassiter Gendreau
Julian Lassiter Gendreau
AFAustin Feng
Austin Feng
LKLily H Kim
Lily H Kim
AHAllen Ho
Allen Ho
AVAnand Veeravagu
Anand Veeravagu
Robot-assisted spine surgery has recently emerged as a viable tool to enable less invasive and higher precision surgery. The first-ever spine robot, the SpineAssist (Mazor Robotics Ltd., Caesarea, Israel), gained FDA approval in 2004. With its ability to provide real-time intraoperative navigation and rigid stereotaxy, robotic-assisted surgery has the potential to increase accuracy while decreasing radiation exposure, complication rates, operative time, and recovery time. Currently, robotic assistance is mainly restricted to spinal fusion and instrumentation procedures, but recent studies have demonstrated its use in increasingly complex procedures such as spinal tumor resections and ablations, vertebroplasties, and deformity correction. However, robots do require high initial costs and training, and thus, require justification for their incorporation into common practice. In this review, we discuss the history of spinal robots along as well as currently available systems. We then examine the literature to evaluate accuracy, operative time, complications, radiation exposure, and costs – comparing robotic-assisted to traditional fluoroscopy-assisted freehand approaches. Finally, we consider future applications for robots in spine surgery.

1 May 2020 in Journal of Neurosurgery
Verified
Journal Article
Closed access
PDF file
MDMarissa D'Souza
Marissa D'Souza
KCKevin S. Chen
Kevin S. Chen
JRJarrett Rosenberg
Jarrett Rosenberg
WEW. Jeffrey Elias
W. Jeffrey Elias
HEHoward M. Eisenberg
Howard M. Eisenberg
PGPejman Ghanouni
Pejman Ghanouni
OBJECTIVE: Skull density ratio (SDR) assesses the transparency of the skull to ultrasound. Magnetic resonance–guided focused ultrasound (MRgFUS) thalamotomy in essential tremor (ET) patients with a lower SDR may be less effective, and the risk for complications may be increased. To address these questions, the authors analyzed clinical outcomes of MRgFUS thalamotomy based on SDRs.METHODS: In 189 patients, 3 outcomes were correlated with SDRs. Efficacy was based on improvement in Clinical Rating Scale for Tremor (CRST) scores 1 year after MRgFUS. Procedural efficiency was determined by the ease of achieving a peak voxel temperature of 54°C. Safety was based on the rate of the most severe procedure-related adverse event. SDRs were categorized at thresholds of 0.45 and 0.40, selected based on published criteria.RESULTS: Of 189 patients, 53 (28%) had an SDR < 0.45 and 20 (11%) had an SDR < 0.40. There was no significant difference in improvement in CRST scores between those with an SDR ≥ 0.45 (58% ± 24%), 0.40 ≤ SDR < 0.45 (i.e., SDR ≥ 0.40 but < 0.45) (63% ± 27%), and SDR < 0.40 (49% ± 28%; p = 0.0744). Target temperature was achieved more often in those with an SDR ≥ 0.45 (p < 0.001). Rates of adverse events were lower in the groups with an SDR < 0.45 (p = 0.013), with no severe adverse events in these groups.CONCLUSIONS: MRgFUS treatment of ET can be effectively and safely performed in patients with an SDR < 0.45 and an SDR < 0.40, although the procedure is more efficient when SDR ≥ 0.45.

26 September 2019 in Biomedicines
Verified
Journal Article
Open access
PDF file
MDMarissa D'Souza
Marissa D'Souza
NMNicholas A. Macdonald
Nicholas A. Macdonald
Julian Lassiter GendreauJulian Lassiter Gendreau
Julian Lassiter Gendreau
PDPate J. Duddleston
Pate J. Duddleston
AFAustin Feng
Austin Feng
AHAllen Ho
Allen Ho
Spinal fusion is the most widely performed procedure in spine surgery. It is the preferred treatment for a wide variety of pathologies including degenerative disc disease, spondylolisthesis, segmental instability, and deformity. Surgeons have the choice of fusing vertebrae by utilizing cages containing autografts, allografts, demineralized bone matrices (DBMs), or graft substitutes such as ceramic scaffolds. Autografts from the iliac spine are the most commonly used as they offer osteogenic, osteoinductive, and osteoconductive capabilities, all while avoiding immune system rejection. Allografts obtained from cadavers and living donors can also be advantageous as they lack the need for graft extraction from the patient. DBMs are acid-extracted organic allografts with osteoinductive properties. Ceramic grafts containing hydroxyapatite can be readily manufactured and are able to provide osteoinductive support while having a long shelf life. Further, bone-morphogenetic proteins (BMPs), mesenchymal stem cells (MSCs), synthetic peptides, and autologous growth factors are currently being optimized to assist in improving vertebral fusion. Genetic therapies utilizing viral transduction are also currently being devised. This review provides an overview of the advantages, disadvantages, and future directions of currently available graft materials. The current literature on growth factors, stem cells, and genetic therapy is also discussed.

26 September 2012 in Journal of Drug Targeting
Verified
Journal Article
Closed access
LKLakshmi Prasanna Kolluru
Lakshmi Prasanna Kolluru
SRSyed A. A. Rizvi
Syed A. A. Rizvi
MDMarissa D'Souza
Marissa D'Souza
Martin DSouzaMartin DSouza
Martin DSouza
Background: Generally, chemotherapeutic drugs attack on both normal and tumor cells non-specifically causing life threatening side effects, necessitating targeted drug delivery to tumors. Purpose: The purpose of this study is to formulate albumin-based nanoparticles for tumor targeted drug delivery and noninvasive diagnosis. Methods: Albumin based nanoparticles (NPs) were developed as a potential tumor theragnostic agent by entrapping an anti cancer drug, doxorubicin and a near infrared dye, indocyanine green. Theragnostic nanoparticles were prepared using a well established coacervation/nanoprecipitation method followed by lyophilization. The formulation was optimized by varying process parameters using full factorial design of experiments. Release of dye and drug from NPs and physical state of the drug in NPs was studied using DSC. The NPs were injected into tumor bearing mice intravenously and imaged using a bio-imager. Results: The optimized nanoparticle formulation had a particle size of 125.0 ± 1.8 nm, poly dispersity index of 0.180 ± 0.057 and zeta potential of −32.7 ± 0.9 mV. The release of dye and drug from the nanoparticles was determined to be quasi-fickian diffusion mediated. Differential scanning calorimetry (DSC) studies revealed the stability of drug in the NP. The in-vivo studies showed enhanced accumulation of the dye loaded NPs at the tumor site than the dye solution, thus allowing noninvasive tumor monitoring. Conclusion: These results project the newly proposed and evaluated nanoparticle formulation as a potential tumor targeting and imaging delivery system.

14 August 2018 in Cureus
Verified
Journal Article
Open access
PDF file
LKLily H. Kim
Lily H. Kim
MDMarissa D'Souza
Marissa D'Souza
AHAllen Ho
Allen Ho
APArjun V. Pendharkar
Arjun V. Pendharkar
ESEric S. Sussman
Eric S. Sussman
ADAtman Desai
Atman Desai
Surgical treatment may be indicated for select patients with cervical disc disease, whether it is cervical disc herniation or spondylosis due to degenerative changes, acute cervical injury due to trauma, or other underlying cervical pathology. Currently, there are various surgical techniques, including anterior, posterior, or combined approaches, in addition to new interventions being utilized in practice. Ideally, the surgical approach should be selected in consideration of each patient’s clinical presentation, imaging findings, and overall medical comorbidities on an individual basis. But the unique advantages and disadvantages of each surgical technique often complicate the therapy choice in managing cervical disc diseases. Although anterior cervical discectomy and fusion (ACDF) is the most widely accepted procedure performed for both single and multi-level cervical disc diseases, there are multiple modifications to this technique. Surgeons have access to different types of plates, screws, and cages and can adopt newer advances in the field such as stand-alone and minimally invasive techniques when indicated. In short, no consensus exists in terms of a single approach that is preferred for all patients. This article aims to review the standard of care for management of cervical disc disease with a focus on the surgical techniques and, in particular, the anterior approach, exploring the various surgical options within this technique.

12 August 2025 in Neurology
Verified
Journal Article
Closed access
JSJames E. Siegler
James E. Siegler
EGElena Badillo Goicoechea
Elena Badillo Goicoechea
MPMary Penckofer
Mary Penckofer
KEKelsey Eklund
Kelsey Eklund
SYShadi Yaghi
Shadi Yaghi
JTJesse Thon
Jesse Thon
Embolic stroke of undetermined source (ESUS) can be attributed to a variety of potential embolic sources, with differential response to anticoagulation. A multicenter, retrospective observational cohort study (27 sites) of consecutive adult patients with acute ischemic stroke due to ESUS (admitted 2015-2024) was conducted. The aim was to compare outcomes after antiplatelet(s) vs anticoagulant (±antiplatelet) treatment in patients with ESUS across potential embolic sources. The time from admission to the primary composite outcome of recurrent stroke, major bleeding, or death was assessed using adjusted Cox proportional hazard regression (clustered by site) and propensity score (PS) matching with (1) inverse probability of treatment weighting (IPTW) and (2) 10:1 nearest-neighbor matching with replacement, adjusting for age, stroke severity, and potential embolic sources (e.g., left ventricular injury and patent foramen ovale). Recurrent stroke, major bleeding, and death were also assessed as secondary outcomes, with stratification by potential embolic sources. Of the 2,328 included patients (n = 230 treated with anticoagulation), the median age was 65 years (interquartile range [IQR] 54-75), 50% were female, and the median NIH Stroke Scale score was 4 (IQR 2-11). Compared with patients treated using antiplatelet(s) therapies, those treated with anticoagulants were not at a lower risk of the primary outcome in the adjusted Cox model (adjusted hazard ratio [aHR] 1.00, 95% CI 0.69-1.45), adjusted IPTW regression model (aHR 1.15, 95% CI 0.79-1.66), or 10:1 PS-matched regression model (aHR 1.00, 95% CI 0.70-1.44). In patients with left ventricular injury, anticoagulation was associated with a lower rate of the primary outcome (aHR 0.35, 95% CI 0.16-0.77; p-interaction <0.01) and trended toward a lower rate of recurrent ischemic stroke (aHR 0.22, 95% CI 0.05-1.08; p-interaction = 0.04) when compared with patients treated with antiplatelet(s). These real-world data validate randomized trial results in ESUS, which reported no net benefit of anticoagulation over antiplatelet therapy. These data suggest possible benefit of anticoagulation in patients with left ventricular injury, as in previous cohort studies, although the findings are limited by the small number of patients treated with anticoagulation. Future trials should evaluate treatment differences in this subgroup. Cardiac Abnormalities in Stroke Prevention and Risk of Recurrence; registration ID: NCT06398366. Registered on May 3, 2024. This study provides Class III evidence that in patients with ESUS, anticoagulation was not superior to antiplatelet therapy in reducing the risk of recurrent stroke, bleeding, or death.