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Luke G. F. Smith, Nguyen Hoang, Ammar Shaikhouni, and Stephanus Viljoen

Pedicle and lateral mass screws are the most common means of rigid fixation in posterior cervical spine fusions. Various other techniques such as translaminar screw placement, paravertebral foramen screw fixation, sublaminar and spinous process wiring, cement augmentation, and others have been developed for primary fixation or as salvage methods. Use of these techniques can be limited by a prior history of osteotomies, poor bone density, destruction of the bone-screw interface, and unfavorable vascular and osseous anatomy.

Here, the authors report on the novel application of cervical sublaminar polyester bands as an adjunct salvage method or additional fixation point used with traditional methods in the revision of prior constructs. While sublaminar polyester bands have been used for decades in pediatric scoliosis surgery in the thoracolumbar spine, they have yet to be utilized as a method of fixation in the cervical spine. In both cases described here, sublaminar banding proved crucial for fixation points where traditional fixation techniques would have been less than ideal. Further study is required to determine the full application of sublaminar polyester bands in the cervical spine as well as its outcomes.

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Luke G. F. Smith, E. Antonio Chiocca, Gregory J. Zipfel, Adam G. F. Smith, Michael W. Groff, Regis W. Haid, and Russell R. Lonser

OBJECTIVE

The Neurosurgery Research and Education Foundation (NREF) provides research support for in-training and early career neurosurgeon-scientists. To define the impact of this funding, the authors assessed the success of NREF awardees in obtaining subsequent National Institutes of Health (NIH) funding.

METHODS

NREF in-training (Research Fellowship [RF] for residents) and early career awards/awardees (Van Wagenen Fellowship [VW] and Young Clinician Investigator [YCI] award for neurosurgery faculty) were analyzed. NIH funding was defined by individual awardees using the NIH Research Portfolio Online Reporting tool (1985–2014).

RESULTS

Between 1985 and 2014, 207 unique awardees were supported by 218 NREF awards ($9.84 million [M] in funding), including 117 RF ($6.02 M), 32 VW ($1.68 M), and 69 YCI ($2.65 M) awards. Subspecialty funding included neuro-oncology (79 awards; 36% of RF, VW, and YCI awards), functional (53 awards; 24%), vascular (37 awards; 17%), spine (22 awards; 10%), pediatrics (18 awards; 8%), trauma/critical care (5 awards; 2%), and peripheral nerve (4 awards; 2%). These awardees went on to receive $353.90 M in NIH funding that resulted in an overall NREF/NIH funding ratio of 36.0:1 (in dollars). YCI awardees most frequently obtained later NIH funding (65%; $287.27 M), followed by VW (56%; $41.10 M) and RF (31%; $106.59 M) awardees. YCI awardees had the highest NREF/NIH funding ratio (108.6:1), followed by VW (24.4:1) and RF (17.7:1) awardees. Subspecialty awardees who went on to obtain NIH funding included vascular (19 awardees; 51% of vascular NREF awards), neuro-oncology (40 awardees; 51%), pediatrics (9 awardees; 50%), functional (25 awardees; 47%), peripheral nerve (1 awardees; 25%), trauma/critical care (2 awardees; 20%), and spine (2 awardees; 9%) awardees. Subspecialty NREF/NIH funding ratios were 56.2:1 for vascular, 53.0:1 for neuro-oncology, 47.6:1 for pediatrics, 34.1:1 for functional, 22.2:1 for trauma/critical care, 9.5:1 for peripheral nerve, and 0.4:1 for spine. Individuals with 2 NREF awards achieved a higher NREF/NIH funding ratio (83.3:1) compared to those with 1 award (29.1:1).

CONCLUSIONS

In-training and early career NREF grant awardees are an excellent investment, as a significant portion of these awardees go on to obtain NIH funding. Moreover, there is a potent multiplicative impact of NREF funding converted to NIH funding that is related to award type and subspecialty.

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Stephen M. Bergin, Amy L. Dunn, Luke G. F. Smith, and Annie I. Drapeau

The authors report on the clinical course of two infants with severe hemophilia A (HA) and concomitant progressive hydrocephalus that required management with a ventriculoperitoneal shunt. The first child, with known HA, presented with a spontaneous intracranial hemorrhage and acquired hydrocephalus. He underwent cerebrospinal fluid diversion with a temporary external ventricular drain, followed by placement of a ventriculoperitoneal shunt. The second child had hydrocephalus secondary to a Dandy-Walker malformation and was diagnosed with severe HA during preoperative evaluation. He underwent placement of a ventriculoperitoneal shunt after progression of the hydrocephalus. The authors also review the treatment of hydrocephalus in patients with HA and describe the perioperative protocols used in their two cases. Treatment of hydrocephalus in infants with HA requires unique perioperative management to avoid complications.

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Russell R. Lonser, Luke G. F. Smith, Michael Tennekoon, Kavon P. Rezai-Zadeh, Jeffrey G. Ojemann, and Stephen J. Korn

OBJECTIVE

To increase the number of independent National Institutes of Health (NIH)–funded neurosurgeons and to enhance neurosurgery research, the National Institute of Neurological Disorders and Stroke (NINDS) developed two national comprehensive programs (R25 [established 2009] for residents/fellows and K12 [2013] for early-career neurosurgical faculty) in consultation with neurosurgical leaders and academic departments to support in-training and early-career neurosurgeons. The authors assessed the effectiveness of these NINDS-initiated programs to increase the number of independent NIH-funded neurosurgeon-scientists and grow NIH neurosurgery research funding.

METHODS

NIH funding data for faculty and clinical department funding were derived from the NIH, academic departments, and Blue Ridge Institute of Medical Research databases from 2006 to 2019.

RESULTS

Between 2009 and 2019, the NINDS R25 funded 87 neurosurgical residents. Fifty-three (61%) have completed the award and training, and 39 (74%) are in academic practice. Compared to neurosurgeons who did not receive R25 funding, R25 awardees were twice as successful (64% vs 31%) in obtaining K-series awards and received the K-series award in a significantly shorter period of time after training (25.2 ± 10.1 months vs 53.9 ± 23.0 months; p < 0.004). Between 2013 and 2019, the NINDS K12 has supported 19 neurosurgeons. Thirteen (68%) have finished their K12 support and all (100%) have applied for federal funding. Eleven (85%) have obtained major individual NIH grant support. Since the establishment of these two programs, the number of unique neurosurgeons supported by either individual (R01 or DP-series) or collaborative (U- or P-series) NIH grants increased from 36 to 82 (a 2.3-fold increase). Overall, NIH funding to clinical neurological surgery departments between 2006 and 2019 increased from $66.9 million to $157.3 million (a 2.2-fold increase).

CONCLUSIONS

Targeted research education and career development programs initiated by the NINDS led to a rapid and dramatic increase in the number of NIH-funded neurosurgeon-scientists and total NIH neurosurgery department funding.

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Luke G. F. Smith, Eric Milliron, Mai-Lan Ho, Houchun H. Hu, Jerome Rusin, Jeffrey Leonard, and Eric A. Sribnick

Traumatic brain injury (TBI) is a common condition with many potential acute and chronic neurological consequences. Standard initial radiographic evaluation includes noncontrast head CT scanning to rapidly evaluate for pathology that might require intervention. The availability of fast, relatively inexpensive CT imaging has fundamentally changed the clinician’s ability to noninvasively visualize neuroanatomy. However, in the context of TBI, limitations of head CT without contrast include poor prognostic ability, inability to analyze cerebral perfusion status, and poor visualization of underlying posttraumatic changes to brain parenchyma. Here, the authors review emerging advanced imaging for evaluation of both acute and chronic TBI and include QuickBrain MRI as an initial imaging modality. Dynamic susceptibility-weighted contrast-enhanced perfusion MRI, MR arterial spin labeling, and perfusion CT are reviewed as methods for examining cerebral blood flow following TBI. The authors evaluate MR-based diffusion tensor imaging and functional MRI for prognostication of recovery post-TBI. Finally, MR elastography, MR spectroscopy, and convolutional neural networks are examined as future tools in TBI management. Many imaging technologies are being developed and studied in TBI, and some of these may hold promise in improving the understanding and management of TBI.

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Rahul Kumar, David S Hersh, Luke G. F Smith, William E Gordon, Nickalus R Khan, Andrew J Gienapp, Busra Gungor, Michael J Herr, Brandy N Vaughn, L. Madison Michael II, and Paul Klimo Jr.

OBJECTIVE

Neurosurgical residents receive exposure to the subspecialty of pediatric neurosurgery during training. The authors sought to determine resident operative experience in pediatric neurosurgery across Accreditation Council for Graduate Medical Education (ACGME)–accredited neurosurgical programs.

METHODS

During 2018–2019, pediatric neurosurgical case logs for recent graduates or current residents who completed their primary pediatric exposure were collected from US continental ACGME training programs. Using individual resident reports and procedure designations, operative volumes and case diversity were analyzed collectively, according to training site characteristics, and also correlated with the recently described Resident Experience Score (RES).

RESULTS

Of the 114 programs, a total of 316 resident case logs (range 1–19 residents per program) were received from 86 (75%) programs. The median cumulative pediatric case volume per resident was 109 (IQR 75–161). Residents at programs with a pediatric fellowship reported a higher median case volume (143, IQR 96–187) than residents at programs without (91, IQR 66–129; p < 0.0001). Residents at programs that outsource their pediatric rotation had a lower median case volume (84, IQR 52–114) compared with those at programs with an in-house experience (117, IQR 79–170; p < 0.0001). The case diversity index among all programs ranged from 0.61 to 0.80, with no statistically significant differences according to the Accreditation Council for Pediatric Neurosurgery Fellowships designation or pediatric experience site (p > 0.05). The RES correlated moderately (r = 0.44) with median operative volumes per program. A program’s annual pediatric operative volume and duration of pediatric experience were identified as significant predictive factors for median resident operative volume.

CONCLUSIONS

Resident experience in pediatric neurosurgery is variable within and between programs. Case volumes are generally higher for residents at programs with in-house exposure and an accredited fellowship, but case diversity is relatively uniform across all programs. RES provides some insight on anticipated case volume, but other unexplained factors remain.

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David Dornbos III, Christy Monson, CNP, Andrew Look, Kristin Huntoon, Luke G. F. Smith, Jeffrey R. Leonard, Sanjay S. Dhall, and Eric A. Sribnick

OBJECTIVE

While the Glasgow Coma Scale (GCS) has been effective in describing severity in traumatic brain injury (TBI), there is no current method for communicating the possible need for surgical intervention. This study utilizes a recently developed scoring system, the Surgical Intervention for Traumatic Injury (SITI) scale, which was developed to efficiently communicate the potential need for surgical decompression in adult patients with TBI. The objective of this study was to apply the SITI scale to a pediatric population to provide a tool to increase communication of possible surgical urgency.

METHODS

The SITI scale uses both radiographic and clinical findings, including the GCS score on presentation, pupillary examination, and CT findings. To examine the scale in pediatric TBI, a neurotrauma database at a level 1 pediatric trauma center was retrospectively evaluated, and the SITI score for all patients with an admission diagnosis of TBI between 2010 and 2015 was calculated. The primary endpoint was operative intervention, defined as a craniotomy or craniectomy for decompression, performed within the first 24 hours of admission.

RESULTS

A total of 1524 patients met inclusion criteria for the study during the 5-year span: 1469 (96.4%) were managed nonoperatively and 55 (3.6%) patients underwent emergent operative intervention. The mean SITI score was 4.98 ± 0.31 for patients undergoing surgical intervention and 0.41 ± 0.02 for patients treated nonoperatively (p < 0.0001). The area under the receiver operating characteristic (AUROC) curve was used to examine the diagnostic accuracy of the SITI scale in this pediatric population and was found to be 0.98. Further evaluation of patients presenting with moderate to severe TBI revealed a mean SITI score of 5.51 ± 0.31 in 40 (15.3%) operative patients and 1.55 ± 0.02 in 221 (84.7%) nonoperative patients, with an AUROC curve of 0.95.

CONCLUSIONS

The SITI scale was designed to be a simple, objective communication tool regarding the potential need for surgical decompression after TBI. Application of this scale to a pediatric population reveals that the score correlated with the perceived need for emergent surgical intervention, further suggesting its potential utility in clinical practice.

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David S. Hersh, Rahul Kumar, Kenneth A. Moore, Luke G. F. Smith, Christopher L. Tinkle, Jason Chiang, Zoltan Patay, Amar Gajjar, Asim F. Choudhri, Jorge A. Lee-Diaz, Brandy Vaughn, and Paul Klimo Jr.

OBJECTIVE

Biopsies of brainstem lesions are performed to establish a diagnosis in the setting of an atypical clinical or radiological presentation, or to facilitate molecular studies. A better understanding of the safety and diagnostic yield of brainstem biopsies would help guide appropriate patient selection.

METHODS

All patients who underwent biopsy of a brainstem lesion during the period from January 2011 to June 2019 were reviewed. Demographic, radiological, surgical, and outcome data were collected.

RESULTS

A total of 58 patients underwent 65 brainstem biopsies during the study period. Overall, the median age was 7.6 years (IQR 3.9–14.2 years). Twenty-two of the 65 biopsies (34%) were open, 42 (65%) were stereotactic, and 1 was endoscopic. In 3 cases (5%), a ventriculoperitoneal shunt was placed, and in 9 cases (14%), a posterior fossa decompression was performed during the same operative session as the biopsy. An intraoperative MRI (iMRI) was performed in 28 cases (43%). In 3 of these cases (11%), the biopsy was off target and additional samples were obtained during the same procedure. New neurological deficits were noted in 5 cases (8%), including sensory deficits, ophthalmoparesis/nystagmus, facial weakness, and hearing loss; these deficits persisted in 2 cases and were transient in 3 cases. A pseudomeningocele occurred in 1 patient; no patients developed a CSF leak or infection. In 8 cases (13%) an additional procedure was needed to obtain a diagnosis.

CONCLUSIONS

Brainstem biopsies are safe and effective. Target selection and approach should be a collaborative effort. iMRI can be used to assess biopsy accuracy in real time, thereby allowing any adjustment if necessary.