Publications by authors named "Guilherme Porto"

13 Publications

  • Page 1 of 1

Clinical outcomes for patients with lateral lumbar radiculopathy treated by percutaneous endoscopic transforaminal discectomy versus tubular microdiscectomy: A retrospective review.

Clin Neurol Neurosurg 2021 Sep 27;208:106848. Epub 2021 Jul 27.

Medical University of South Carolina, Department of Neurosurgery, Charleston, SC 29425, USA.

Background: Surgical management of lateral lumbar radiculopathy is evolving. TMD (Tubular microdiscectomy) and TELD (Transforaminal endoscopic lumbar discectomy) have emerged as viable MIS treatments. We aim to compare clinical outcomes of both techniques for the treatment of lateral lumbar radiculopathy in relation to pre-operative lumbar foraminal stenosis grade (LFS).

Methods: Retrospective observational cohort study of patients with back and leg pain from single level foraminal nerve root compression that underwent TMD or TELD. Data analyzed included pre- and post-operative VAS leg and back pain, MacNab clinical outcome scores, hospital length of stay, complication rates, and operative time. Outcomes were correlated with a pre-operative MRI grading system for LFS.

Results: 109 patients were enrolled (71 TELD and 38 TMD). Back and leg VAS pain scores improved in TELD and TMD (p < 0.0001). Patients with grade III stenosis showed significantly higher VAS scores (p < 0.01), and worse functional outcomes at latest follow-up compared with grade I/II LFS. Overall, there was no difference in outcome between procedure groups except that TMD VAS back pain scores were lower than TELD at last follow up (p < 0.05). Clinical outcome comparisons between procedures relating to LFS grade showed higher correlation of LFS to TELD (Spearman's rho (ρ)= 0.342 for TMD and 0.606 TELD). Regression analyses demonstrated correlation between higher-grade foraminal stenosis and poorer outcomes in TELD and TMD.

Conclusions: Both TELD and TMD are viable for treating lateral lumbar radiculopathy. Higher-grade foraminal stenosis can be indicative of poorer outcomes regardless of procedure type, however, the severity of pre-operative LFS correlates with clinical outcomes in TELD more significantly than TMD.
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http://dx.doi.org/10.1016/j.clineuro.2021.106848DOI Listing
September 2021

Mechanical Thrombectomy of Carotid Terminus Occlusion Using Direct Aspiration Technique-Video Illustration: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 Jul 31. Epub 2021 Jul 31.

Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA.

Acute carotid terminus occlusion (CTO) is responsible for up to 5% of acute ischemic strokes secondary to emergent large vessel occlusion (ELVO) and up to 20% of acute internal carotid artery (ICA) occlusions.1 The term "CTO" has also been used to describe occlusions in the supra-clinoid segment or at the bifurcation of the ICA. Compared to other ELVOs, patients with CTO present with higher stroke severity and larger infarct volume, likely to be a result of disruption of direct Circle of Willis collaterals across the anterior communicating artery (AComA) and posterior communicating artery (PComA).2,3  Similary, CTO is usually associated with worse prognosis compared to other ELVOs in general. With regard to response to treatment, previous studies have reported significantly lower recanalization rates with intravenous alteplase with CTO compared to M1 segment occlusion. With regard to the safety and efficacy of mechanical thrombectomy, prior reports provide conflicting results with some reporting lower successful recanalization rates with CTO compared to M1 occlusion, and others reporting similar results. In our experience, we have found that successful recanalization of CTO can be achieved with a similar approach to M1 occlusions utilizing a direct aspiration first pass technique (ADAPT).3,4 Herein, we present a case of CTO for which we performed mechanical thrombectomy using ADAPT. This procedure was an emergent standard of care procedure for which a consent was not required and so not obtained.
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http://dx.doi.org/10.1093/ons/opab272DOI Listing
July 2021

Endovascular Management of Distal Anterior Cerebral Artery Aneurysms: A Multicenter Retrospective Review.

World Neurosurg 2021 Jul 18. Epub 2021 Jul 18.

Department of Neurosurgery, Division of Neuroendovascular Surgery, Medical University of South Carolina, Charleston, South Carolina, USA.

Introduction: Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA.

Methods: A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up.

Results: A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access.

Conclusion: Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes.
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http://dx.doi.org/10.1016/j.wneu.2021.07.055DOI Listing
July 2021

Neuroendovascular Management of Acute Ischemic Basilar Strokes: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 Sep;21(4):E346-E347

Division of Neuroendovascular Surgery, Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA.

Basilar artery occlusions (BAOs) are devastating ischemic strokes that account for 1% of all strokes with high morbidity and mortality; however, neuroendovascular techniques such as ADAPT have recently revolutionized the clinical outcomes of these patients.1-3 Common underlying pathology in patients with BAO include intracranial atherosclerotic disease (ICAD) as well as thromboembolic origin.4 Basilar artery ICAD in a setting of acute stroke portends a poor prognosis and post-thrombectomy residual critical flow limiting stenosis treatment options, including balloon angioplasty with or without stent placement.5-7 We present a video illustration of neuroendovascular technique and challenges encountered when managing this pathology. Image at 5:42 reprinted with permission from Alawieh et al, Lessons learned over more than 500 stroke thrombectomies using ADAPT with increasing aspiration catheter size, Neurosurgery, 86(1), 2020, pp. 61-70, with permission from the Congress of Neurological Surgeons.1.
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http://dx.doi.org/10.1093/ons/opab180DOI Listing
September 2021

Endovascular Treatment of Basilar Bifurcation Aneurysms With PulseRider-Assisted Coiling: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 Jul;21(2):E109-E110

Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA.

Wide-necked bifurcation aneurysms pose technical and anatomical challenges to endovascular treatment, which make the simpler assisted (balloon or single stent) coiling techniques less effective.1 Consequently, unique endovascular solutions to treat such aneurysms have been devised.2,3 One such device is PulseRider (Cerenovus, New Brunswick, New Jersey), which is designed to provide neck support for a coil mass while protecting the bifurcation.3 The device comprises a body or stem that is deployed in the parent artery and a saddle component that sits at the aneurysm neck to keep the coil mass away from the bifurcation. There are several technical nuances involved in successful use of the device during positioning, deployment, and detachment.3 We present a surgical video detailing the steps of PulseRider-assisted coiling of unruptured basilar bifurcation (or basilar apex) aneurysms. The first case highlights index treatment at diagnosis and the second showcases treatment of a recurrent basilar apex aneurysm. Both patients provided informed consent to the procedure. We also briefly discuss the rationale for treating basilar apex aneurysms.4,5.
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http://dx.doi.org/10.1093/ons/opab102DOI Listing
July 2021

Preconditioning with INC280 and LDK378 drugs sensitizes MGMT-unmethylated glioblastoma to temozolomide: Pre-clinical assessment.

J Neurol Sci 2020 Nov 21;418:117102. Epub 2020 Aug 21.

Department of Neurosurgery and MUSC Brain & Spine Tumor Program, Medical University of South Carolina, Charleston, SC, United States of America.

Temozolomide (TMZ) therapy is the standard of care for patients with glioblastoma (GBM). Clinical studies have shown that elevated levels of DNA repair protein O (6)-methylguanine-DNA methyltransferase (MGMT) or deficiency/defect of DNA mismatch repair (MMR) genes is associated with TMZ resistance in some, but not all, GBM tumors. Another reason for GBM treatment failure is signal redundancy due to coactivation of several functionally linked receptor tyrosine kinases (RTKs), including anaplastic lymphoma kinase (ALK) and c-Met (hepatocyte growth factor receptor). As such, these tyrosine kinases serve as potential targets for GBM therapy. Thus, we tested two novel drugs: INC280 (Capmatinib: a highly selective c-Met receptor tyrosine kinase-RTK inhibitor) and LDK378 (Ceritinib: a highly selective anaplastic lymphoma kinase-ALK inhibitor), aiming to overcome TMZ resistance in MGMT-unmethylated GBM cells in in vitro cell culture models. Treatments were examined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, caspase-3 assay and western blot analysis. Results obtained from our experiments demonstrated that preconditioning with INC280 and LDK378 drugs exhibit increased MMR protein expression, specifically MMR protein MLH1 (MutL Homolog 1) and MSH6 (MutS Homolog 6) and sensitized TMZ in MGMT-unmethylated GBM cells via suppression of ALK and c-Met expression. INC280 and LDK378 plus TMZ also induced apoptosis by modulating downstream signaling of PI3K/AKT/STAT3. Taken together, this data indicates that co-inhibition of ALK and c-MET can enhance growth inhibitory effects in MGMT-unmethylated cells and enhance TMZ sensitivity in-vitro, suggesting c-Met inhibitors combined with ALK-targeting provide a therapeutic benefit in MGMT-unmethylated GBM patients.
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http://dx.doi.org/10.1016/j.jns.2020.117102DOI Listing
November 2020

Effect of Dovitinib (TKI258), a Multi-Target Angiokinase Inhibitor on Aggressive Meningioma Cells.

Cancer Invest 2020 Jul 8;38(6):349-355. Epub 2020 Jun 8.

Department of Neurosurgery and MUSC Brain & Spine Tumor Program, Medical University of South Carolina, Charleston, South Carolina, USA.

Meningiomas represent ∼30% of primary central nervous system (CNS) tumors. Although advances in surgery and radiotherapy have significantly improved survival, there remains an important subset of patients whose tumors have more aggressive behavior and are refractory to conventional therapy. Recent advances in molecular genetics and epigenetics suggest that this aggressive behavior may be due to the deletion of the DNA repair and tumor suppressor gene, neurofibromatosis Type 2 (NF2) mutation on chromosome 22q12, and genetic abnormalities in multiple RTKs including FGFRs. Management of higher-grade meningiomas, such as anaplastic meningiomas (AM: WHO grade III), is truly challenging and there isn't an established chemotherapy option. We investigate the effect of active multi tyrosine receptor kinase inhibitor Dovitinib at stopping AM cell growth in with either frequent codeletion or mutated and gene. Treatment effects were assessed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, western blot analysis, caspases assay, and DNA fragmentation assay. Treatment of CH157MN and IOMM-Lee cells with Dovitinib suppressed multiple angiokinases-mainly FGFRs, leading to suppression of downstream signaling by RAS-RAF-MAPK molecules and PI3K-AKT molecules which are involved in cell proliferation, cell survival, and tumor invasion. Furthermore, Dovitinib induced apoptosis via downregulation of survival proteins (Bcl-XL), and over-expression of apoptotic factors (Bax and caspase-3) regardless of CHEK2 and NF2 mutation status.: This study establishes the groundwork for development of Dovitinib as a therapeutic agent for high-grade AM with either frequent codeletion or mutated and , an avenue with high translational potential.
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http://dx.doi.org/10.1080/07357907.2020.1773844DOI Listing
July 2020

Cystic angiomatosis skull lesion obliteration with neuroendovascular sclerotherapy as a unique treatment: case report.

J Neurosurg Pediatr 2020 May 8:1-5. Epub 2020 May 8.

Departments of1Neurosurgery and.

Cystic angiomatosis is a rare bone condition with complex presentation and difficult treatment. Current management strategies have poorly tolerated side effects and a low likelihood of disease eradication. The control of calvarial lesions that are symptomatic usually involves surgical excision and subsequent cranioplasty. This paradigm can present with a risk of morbidity and mortality depending on the anatomy of the lesion. Here, the authors present a novel approach to a difficult-to-treat occipital calvarial lesion directly overlying the transverse sinus, performing a small, partial-thickness craniectomy and alcohol sclerotherapy in a combined neurosurgery-neuroendovascular approach. At 3 years after treatment, the authors noted a complete, encouraging radiographic and clinical outcome.
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http://dx.doi.org/10.3171/2020.3.PEDS2045DOI Listing
May 2020

Venous Thromboprophylaxis in Spine Surgery.

Global Spine J 2020 Jan 19;10(1 Suppl):65S-70S. Epub 2019 Jun 19.

Carle Clinic, Champaign-Urbana, IL, USA.

Study Design: Review article.

Objective: A review of the literature on postoperative initiation of thrombophylactic agents following spine surgery.

Methods: A review of the literature and synthesis of the data to provide an update on venous thromboprophylaxis following spine surgery.

Results: Postoperative regimens of venous thromboprophylaxis measures following spine surgery remain a controversial issue. Recommendations regarding mechanical versus chemical prophylaxis vary greatly among institutions.

Conclusion: Postoperative spine surgery initiation of thromboprophylaxis remains controversial regarding optimal timing and agent selection. The benefits of deep vein thrombosis/pulmonary embolism prophylaxis must be weighed against the possible postoperative complications associated with spine surgery.
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http://dx.doi.org/10.1177/2192568219858307DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6947674PMC
January 2020

Anticoagulation and Spine Surgery.

Global Spine J 2020 Jan 6;10(1 Suppl):53S-64S. Epub 2020 Jan 6.

University of Virginia, Charlottesville, VA, USA.

Study Design: Literature review.

Objective: Preoperative management of therapeutic anticoagulation in spine surgery is critical to minimize risk of thromboembolic events yet prevent postsurgical complications. Limited research is available, and most guidelines are based on drug half-lives. We aim to clarify current guidelines and available evidence for safe practice of spine surgery in this patient population.

Methods: A literature search in PubMed was done encompassing comprehensive search terms to locate published literature on anticoagulation and spine surgery. Predefined inclusion and exclusion criteria were applied and data extraction was performed.

Results: A total of 17 articles met the final inclusion criteria. Of these, 12 articles were retrospective chart reviews, 3 were prospective observational studies, and 2 were systematic reviews. Current practice suggests holding warfarin until international normalized ratio <1.4, anti-Xa drugs for 48 to 72 hours, 12 to 24 hours for low-molecular-weight heparin, and 4 to 24 hours for heparin, before surgery. Antiplatelet agents can be stopped for 1 to 3 days prior to operation (81-500 mg) but must be stopped for 1 week for doses >1 g/d. For Plavix, 5 to 7 days of discontinuation advised to prevent complications.

Conclusions: This review provides an overview of main anticoagulation agents seen in preoperative setting for spine patients. Although data is mixed and no true randomized control trials are available, there is growing evidence suggesting the aforementioned guidelines are needed to optimize anticoagulation in setting of spine surgery. Further studies are needed to elucidate risk of complications while operating under therapeutic levels of anticoagulation for a variety of comorbid conditions.
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http://dx.doi.org/10.1177/2192568219852051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6947673PMC
January 2020

Thrombectomy for acute ischemic stroke in the elderly: a 'real world' experience.

J Neurointerv Surg 2018 Dec 17;10(12):1209-1217. Epub 2018 Apr 17.

Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA.

Introduction: Completed randomized trials on endovascular thrombectomy (ET) did not independently assess the efficacy of ET in the elderly (≥80 years old) who were often excluded or under-represented in trials. There were also inconsistent criteria for patient selection in this population across the different trials. This work evaluates outcomes after ET for acute ischemic stroke (AIS) in the elderly at a high volume stroke center.

Methods: We reviewed all cases of AIS that underwent a direct aspiration first pass technique (ADAPT) thrombectomy for large vessel occlusions between March 2013 and October 2017 while comparing outcomes in the elderly with younger counterparts. We also reviewed AIS cases in elderly patients undergoing medical management who were matched to the ET counterparts by demographics, comorbidities, baseline deficits, and stroke severity.

Results: Of 560 patients undergoing ET for AIS, 108 patients were in the elderly group (≥80 years of age), and had a significantly lower likelihood of functional independence (defined as a modified Rankin Scale score of 0-2) at 90 days compared with younger patients (20.5% vs 44.4%, P<0.001), and higher mortality rates (34.3% vs 20%, P<0.001). When compared with patients undergoing medical management, elderly patients did not have a significant improvement in rates of good outcomes (20.5% vs 19.5%, P>0.05), and had significantly higher rates of hemorrhage (40.7% vs 9.3%, P<0.001). We also identified baseline stroke severity and the incidence of hemorrhage as two independent predictors of outcome in the elderly patients.

Conclusions: ET in the elderly did not show a similar benefit to younger patients when compared with medical management. These findings emphasize the need for more optimal selection criteria for the elderly population to improve the risk to benefit ratio of ET.
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http://dx.doi.org/10.1136/neurintsurg-2018-013787DOI Listing
December 2018

Progressive Brown-Séquard syndrome: A rare manifestation of cervical disc herniation.

J Clin Neurosci 2016 Jul 23;29:196-8. Epub 2016 Feb 23.

Department of Neurosurgery, Rush University Medical Center, 1725 W Harrison Street, Suite 855, Chicago, IL 60612, USA.

Brown-Séquard syndrome (BSS) is a rare syndrome and is often described in association with spinal cord injury resulting from hemisection of the spinal cord. BSS due to cervical disc herniation is rare with often delayed diagnosis. The importance of early recognition with imaging cannot be over-emphasized, as the prognosis is better when compared to traumatic and vascular etiologies of BSS. We report a rare case of BBS in an 86-year-old man secondary to cervical disc herniation who had dramatic improvement after surgical intervention. This case highlights the unusual presentation from a very common spinal pathology along with a review of the pertinent literature.
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http://dx.doi.org/10.1016/j.jocn.2015.12.021DOI Listing
July 2016

Blood Pressure Guideline Adherence in Patients with Ischemic and Hemorrhagic Stroke in the Neurointensive Care Unit Setting.

Neurocrit Care 2015 Dec;23(3):313-20

Department of Neurosciences, MUSC, Charleston, SC, USA.

Background And Purpose: Patients with acute brain injuries require strict physiologic control to minimize morbidity and mortality. This study aimed to assess in-hospital compliance to strict physiologic parameters (BP, HR, ICP, SpO2) in these populations.

Methods: Patients with severe cerebrovascular events were admitted to the neurointensive care unit (NSICU) and were continuously monitored using the BedMasterEX (Excel Medical Electronics Inc, FL) system, which recorded hemodynamic data via an arterial catheter continuously in 5-s intervals. Furthermore, we investigated the impact of healthcare provider shift changes (6-8 a.m./p.m) and of day (6 a.m.-6 p.m.) versus night (6 p.m-6 a.m) shifts in hemodynamic control.

Results: Fifty patients admitted to the NSICU, 50 % male, mean age 59.7 ± 13.9 years with subarachnoid hemorrhage (23), ischemic stroke (8), subdural hematoma (4), intracerebral hemorrhage (3), intraventricular hemorrhage (2), and miscellaneous injuries (10) were enrolled. Data represented 2,337 total hours of continuous monitoring. Systolic BPs (SBP) were on average outside of recommended ranges 32.26 ± 30.46 % of the monitoring period. We subdivided adherence to ideal SBP range: optimal (≥99 % of time spent in NSICU within range) was achieved in 12 %, adequate (90 %) in 16 %, suboptimal (80 %) in 20 %, inadequate I (70 %) in 12 %, and inadequate II (<70 %) in 40 % of patients. Comparison of shift change %time and day versus night %time out of parameter yielded no statistically significant differences across SAH patients.

Conclusion: Hemodynamic management of patients with cerebrovascular injuries, based on targeted thresholds in the NSICU, yielded optimal control of SBP in only 28 % of our patients (within parameters ≥90 % of time).
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http://dx.doi.org/10.1007/s12028-015-0116-yDOI Listing
December 2015
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