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Natalie Limoges, Erin D’Agostino, Aaron Gelinne, Cormac O. Maher, R. Michael Scott, Gerald Grant, Mark D. Krieger, David D. Limbrick Jr., Michael White, and Susan Durham

OBJECTIVE

Pediatric neurosurgery is a core component of neurosurgical residency training. Pediatric case minimums are established by the Neurosurgery Residency Review Committee of the Accreditation Council for Graduate Medical Education (ACGME). Case minimums, by themselves, allow for great variability in training between programs. There are no prior data on how the residency programs meet these requirements. The authors’ objective was to gather information on pediatric neurosurgical education among the ACGME-accredited neurosurgery training programs in order to shape further pediatric neurosurgical educational efforts.

METHODS

A 25-question survey about pediatric neurosurgical education was created by the Education Committee of the Section on Pediatric Neurological Surgery of the American Association of Neurological Surgeons/Congress of Neurological Surgeons and distributed to program directors of all 111 ACGME-accredited neurosurgery training programs.

RESULTS

The response rate was 77% (86/111). In 55% of programs the residents are rotated to a responder-designated “freestanding” children’s hospital, and 39% of programs rotate residents to a children’s hospital within a larger adult hospital or a general hospital. There are 4 or fewer pediatric neurosurgical faculty in 91% of programs. In 12% of programs less than 100 cases are performed per year, and in 45% more than 500 are performed. In 31% of responding neurosurgery residency programs there is also a pediatric neurosurgery fellowship program supported by the same sponsoring institution. Seventy-seven percent of programs have at least one specific pediatric neurosurgery rotation, with 71% of those rotations occurring during postgraduate year 3 and 50% occurring during postgraduate year 4. The duration of pediatric rotation varies from no specific rotation to more than 1 year, with 48% of residents spending 4–6 months on a pediatric rotation and 12% spending 7–11 months. Last, 17% of programs send their residents to external sites sponsoring other residency programs for their pediatric rotation.

CONCLUSIONS

There is great variety between neurosurgery training programs with regard to resident education in pediatric neurosurgery. This study’s data will serve as a baseline for future studies, and the authors hope the findings will guide further efforts in pediatric neurosurgical education in residency training programs.

Free access

Gabe Haller, Brooke Sadler, Timothy Kuensting, Nivan Lakshman, Jacob K. Greenberg, Jennifer M. Strahle, Tae Sung Park, Matthew B. Dobbs, Christina A. Gurnett, and David D. Limbrick Jr.

OBJECTIVE

Chiari I malformation (CM-I) has traditionally been defined by measuring the position of the cerebellar tonsils relative to the foramen magnum. The relationships of tonsillar position to clinical presentation, syringomyelia, scoliosis, and the use of posterior fossa decompression (PFD) surgery have been studied extensively and yielded inconsistent results. Obex position has been proposed as a useful adjunctive descriptor for CM-I and may be associated with clinical disease severity.

METHODS

A retrospective chart review was performed of 442 CM-I patients with MRI who presented for clinical evaluation between 2003 and 2018. Clinical and radiological variables were measured for all patients, including presence/location of headaches, Chiari Severity Index (CSI) grade, tonsil position, obex position, clival canal angle, pB-C2 distance, occipitalization of the atlas, basilar invagination, syringomyelia, syrinx diameter, scoliosis, and use of PFD. Radiological measurements were then used to predict clinical characteristics using regression and survival analyses, with performing PFD, the presence of a syrinx, and scoliosis as outcome variables.

RESULTS

Among the radiological measurements, tonsil position, obex position, and syringomyelia were each independently associated with use of PFD. Together, obex position, tonsil position, and syringomyelia (area under the curve [AUC] 89%) or obex position and tonsil position (AUC 85.4%) were more strongly associated with use of PFD than tonsil position alone (AUC 76%) (Pdiff = 3.4 × 10−6 and 6 × 10−4, respectively) but were only slightly more associated than obex position alone (AUC 82%) (Pdiff = 0.01 and 0.18, respectively). Additionally, obex position was significantly associated with occipital headaches, CSI grade, syringomyelia, and scoliosis, independent of tonsil position. Tonsil position was associated with each of these traits when analyzed alone but did not remain significantly associated with use of PFD when included in multivariate analyses with obex position.

CONCLUSIONS

Compared with tonsil position alone, obex position is more strongly associated with symptomatic CM-I, as measured by presence of a syrinx, scoliosis, or use of PFD surgery. These results support the role of obex position as a useful radiological measurement to inform the evaluation and potentially the management of CM-I.

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Jennifer M. Strahle, Rukayat Taiwo, Christine Averill, James Torner, Jordan I. Gewirtz, Chevis N. Shannon, Christopher M. Bonfield, Gerald F. Tuite, Tammy Bethel-Anderson, Richard C. E. Anderson, Michael P. Kelly, Joshua S. Shimony, Ralph G. Dacey Jr., Matthew D. Smyth, Tae Sung Park, David D. Limbrick Jr., and for the Park-Reeves Syringomyelia Research Consortium

OBJECTIVE

In patients with Chiari malformation type I (CM-I) and a syrinx who also have scoliosis, clinical and radiological predictors of curve regression after posterior fossa decompression are not well known. Prior reports indicate that age younger than 10 years and a curve magnitude < 35° are favorable predictors of curve regression following surgery. The aim of this study was to determine baseline radiological factors, including craniocervical junction alignment, that might predict curve stability or improvement after posterior fossa decompression.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and a syrinx (≥ 3 mm in width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°) in patients who underwent posterior fossa decompression and who also had follow-up imaging.

RESULTS

Of 825 patients with CM-I and a syrinx, 251 (30.4%) were noted to have scoliosis present at the time of diagnosis. Forty-one (16.3%) of these patients underwent posterior fossa decompression and had follow-up imaging to assess for scoliosis. Twenty-three patients (56%) were female, the mean age at time of CM-I decompression was 10.0 years, and the mean follow-up duration was 1.3 years. Nine patients (22%) had stable curves, 16 (39%) showed improvement (> 5°), and 16 (39%) displayed curve progression (> 5°) during the follow-up period. Younger age at the time of decompression was associated with improvement in curve magnitude; for those with curves of ≤ 35°, 17% of patients younger than 10 years of age had curve progression compared with 64% of those 10 years of age or older (p = 0.008). There was no difference by age for those with curves > 35°. Tonsil position, baseline syrinx dimensions, and change in syrinx size were not associated with the change in curve magnitude. There was no difference in progression after surgery in patients who were also treated with a brace compared to those who were not treated with a brace for scoliosis.

CONCLUSIONS

In this cohort of patients with CM-I, a syrinx, and scoliosis, younger age at the time of decompression was associated with improvement in curve magnitude following surgery, especially in patients younger than 10 years of age with curves of ≤ 35°. Baseline tonsil position, syrinx dimensions, frontooccipital horn ratio, and craniocervical junction morphology were not associated with changes in curve magnitude after surgery.

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Akshitkumar M. Mistry, Nishit Mummareddy, Travis S. CreveCoeur, Jock C. Lillard, Brandy N. Vaughn, Jean-Nicolas Gallant, Andrew T. Hale, Natalie Griffin, John C. Wellons III, David D. Limbrick Jr., Paul Klimo Jr., and Robert P. Naftel

OBJECTIVE

The subventricular zone (SVZ), housed in the lateral walls of the lateral ventricles, is the largest neurogenic niche in the brain. In adults, high-grade gliomas in contact or involved with the SVZ are associated with decreased survival. Whether this association holds true in the pediatric population remains unexplored. To address this gap in knowledge, the authors conducted this retrospective study in a pediatric population with high-grade gliomas treated at three comprehensive centers in the United States.

METHODS

The authors retrospectively identified 63 patients, age ≤ 21 years, with supratentorial WHO grade III–IV gliomas treated at three academic centers. Basic demographic and clinical data regarding presenting signs and symptoms and common treatment variables were obtained. Preoperative MRI studies were evaluated to assess SVZ contact by tumor and to quantify tumor volume.

RESULTS

Sixty-three patients, including 34 males (54%), had a median age of 12.3 years (IQR 6.50–16.2) and a median tumor volume of 39.4 ml (IQR 19.4–65.8). Tumors contacting the SVZ (SVZ+) were noted in 34 patients (54%) and overall were larger than those not in contact with the SVZ (SVZ−; 51.1 vs 27.3, p = 0.002). The SVZ+ tumors were also associated with decreased survival. However, age, tumor volume, tumor grade, and treatment with chemotherapy and/or radiation were not associated with survival in the 63 patients. In the univariable analysis, near-total resection, gross-total resection, and seizure presentation were associated with increased survival (HR = 0.23, 95% CI 0.06–0.88, p = 0.03; HR = 0.26, 95% CI 0.09–0.74, p = 0.01; and HR = 0.46, 95% CI 0.22–0.97, p = 0.04, respectively). In a multivariable stepwise Cox regression analysis, only SVZ+ tumors remained significantly associated with decreased survival (HR = 1.94, 95% CI 1.03–3.64, p = 0.04).

CONCLUSIONS

High-grade glioma contact with the SVZ neural stem cell niche was associated with a significant decrease in survival in the pediatric population, as it is in the adult population. This result suggests that tumor contact with the SVZ is a general negative prognosticator in high-grade glioma independent of age group and invites biological investigations to understand the SVZ’s role in glioma pathobiology.

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Jonathan Pindrik, Jay Riva-Cambrin, Abhaya V. Kulkarni, Jessica S. Alvey, Ron W. Reeder, Ian F. Pollack, John C. Wellons III, Eric M. Jackson, Curtis J. Rozzelle, William E. Whitehead, David D. Limbrick Jr., Robert P. Naftel, Chevis Shannon, Patrick J. McDonald, Mandeep S. Tamber, Todd C. Hankinson, Jason S. Hauptman, Tamara D. Simon, Mark D. Krieger, Richard Holubkov, John R. W. Kestle, and for the Hydrocephalus Clinical Research Network

OBJECTIVE

Few studies have addressed surgical resource utilization—surgical revisions and associated hospital admission days—following shunt insertion or endoscopic third ventriculostomy (ETV) with or without choroid plexus cauterization (CPC) for CSF diversion in hydrocephalus. Study members of the Hydrocephalus Clinical Research Network (HCRN) investigated differences in surgical resource utilization between CSF diversion strategies in hydrocephalus in infants.

METHODS

Patients up to corrected age 24 months undergoing initial definitive treatment of hydrocephalus were reviewed from the prospectively maintained HCRN Core Data Project (Hydrocephalus Registry). Postoperative courses (at 1, 3, and 5 years) were studied for hydrocephalus-related surgeries (primary outcome) and hospital admission days related to surgical revision (secondary outcome). Data were summarized using descriptive statistics and compared using negative binomial regression, controlling for age, hydrocephalus etiology, and HCRN center. The study population was organized into 3 groups (ETV alone, ETV with CPC, and CSF shunt insertion) during the 1st postoperative year and 2 groups (ETV alone and CSF shunt insertion) during subsequent years due to limited long-term follow-up data.

RESULTS

Among 1090 patients, the majority underwent CSF shunt insertion (CSF shunt, 83.5%; ETV with CPC, 10.0%; and ETV alone, 6.5%). Patients undergoing ETV with CPC had a higher mean number of revision surgeries (1.2 ± 1.6) than those undergoing ETV alone (0.6 ± 0.8) or CSF shunt insertion (0.7 ± 1.3) over the 1st year after surgery (p = 0.005). At long-term follow-up, patients undergoing ETV alone experienced a nonsignificant lower mean number of revision surgeries (0.7 ± 0.9 at 3 years and 0.8 ± 1.3 at 5 years) than those undergoing CSF shunt insertion (1.1 ± 1.9 at 3 years and 1.4 ± 2.6 at 5 years) and exhibited a lower mean number of hospital admission days related to revision surgery (3.8 ± 10.3 vs 9.9 ± 27.0, p = 0.042).

CONCLUSIONS

Among initial treatment strategies for hydrocephalus, ETV with CPC yielded a higher surgical revision rate within 1 year after surgery. Patients undergoing ETV alone exhibited a nonsignificant lower mean number of surgical revisions than CSF shunt insertion at 3 and 5 years postoperatively. Additionally, the ETV-alone cohort demonstrated significantly fewer hospital admission days related to surgical management of hydrocephalus within 3 years after surgery. These findings suggest a time-dependent benefit of ETV over CSF shunt insertion regarding surgical resource utilization.

Free access

Jordan I. Gewirtz, Alex Skidmore, Matthew D. Smyth, David D. Limbrick Jr., Manu Goyal, Joshua S. Shimony, Robert C. McKinstry, Mari L. Groves, and Jennifer M. Strahle

OBJECTIVE

The immediate and long-term risk of anesthesia in the pediatric population is controversial. Traditional spine MRI protocols require the patient to remain still during the examination, and in young children this frequently results in the need for sedation administration. The authors’ goal was to develop an abbreviated spine MRI protocol to reduce sedation administration in young patients undergoing spine MRI.

METHODS

After IRB approval, the medical records of all pediatric patients who underwent a fast spine MRI protocol between 2017 and 2019 were reviewed. The protocol consisted of T2-weighted half-Fourier acquisition single-shot turbo spin echo, T1-weighted turbo spin echo, and T2-weighted STIR sequences acquired in the sagittal plane. The total acquisition time was 2 minutes with no single sequence acquisition longer than 60 seconds. Interpretability of the scans was assessed in accordance with the radiology report in conjunction with the neurosurgeon’s clinical notes.

RESULTS

A total of 47 fast spine MRI sessions were performed in 45 patients. The median age at the time of the MRI was 2.4 years (25th–75th quartile, 1.1–4.3 years; range 0.16–18.58 years). The most common indication for imaging was to rule out or follow a known syrinx (n = 30), followed by the need to rule out or follow known spinal dysraphism (n = 22). There were no uninterpretable or unusable scans. Eight of 47 scans were noted to have moderate motion artifact limitations with respect to the quality of the scan. Seven patients underwent a subsequent MRI with a sedated standard spine protocol within 1 year from the fast scan, which confirmed the findings on the fast MRI protocol with no new findings identified.

CONCLUSIONS

The authors report the first pediatric series of a fast spine MRI protocol for use in young patients. The protocol does not require sedation and is able to identify and monitor syrinx, spinal dysraphism, and potentially other intraspinal anomalies.

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Jacob K. Greenberg and David D. Limbrick Jr.

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Jason S. Hauptman, John Kestle, Jay Riva-Cambrin, Abhaya V. Kulkarni, Samuel R. Browd, Curtis J. Rozzelle, William E. Whitehead, Robert P. Naftel, Jonathan Pindrik, David D. Limbrick Jr., James Drake, John C. Wellons III, Mandeep S. Tamber, Chevis N. Shannon, Tamara D. Simon, Ian F. Pollack, Patrick J. McDonald, Mark D. Krieger, Jason Chu, Todd C. Hankinson, Eric M. Jackson, Jessica S. Alvey, Ron W. Reeder, Richard Holubkov, and for the Hydrocephalus Clinical Research Network

OBJECTIVE

The primary objective of this study was to use the prospective Hydrocephalus Clinical Research Network (HCRN) registry to determine clinical predictors of fast time to shunt failure (≤ 30 days from last revision) and ultrafast time to failure (≤ 7 days from last revision).

METHODS

Revisions (including those due to infection) to permanent shunt placements that occurred between April 2008 and November 2017 for patients whose entire shunt experience was recorded in the registry were analyzed. All registry data provided at the time of initial shunt placement and subsequent revision were reviewed. Key variables analyzed included etiology of hydrocephalus, age at time of initial shunt placement, presence of slit ventricles on imaging at revision, whether the ventricles were enlarged at the time of revision, and presence of prior fast failure events. Univariable and multivariable analyses were performed to find key predictors of fast and ultrafast failure events.

RESULTS

A cohort of 1030 patients with initial shunt insertions experienced a total of 1995 revisions. Of the 1978 revision events with complete records, 1216 (61.5%) shunts remained functional for more than 1 year, and 762 (38.5%) failed within 1 year of the procedure date. Of those that failed within 1 year, 423 (55.5%) failed slowly (31–365 days) and 339 (44.5%) failed fast (≤ 30 days). Of the fast failures, 131 (38.6%) were ultrafast (≤ 7 days). In the multivariable analysis specified a priori, etiology of hydrocephalus (p = 0.005) and previous failure history (p = 0.011) were independently associated with fast failure. Age at time of procedure (p = 0.042) and etiology of hydrocephalus (p = 0.004) were independently associated with ultrafast failure. These relationships in both a priori models were supported by the data-driven multivariable models as well.

CONCLUSIONS

Neither the presence of slit ventricle syndrome nor ventricular enlargement at the time of shunt failure appears to be a significant predictor of repeated, rapid shunt revisions. Age at the time of procedure, etiology of hydrocephalus, and the history of previous failure events seem to be important predictors of fast and ultrafast shunt failure. Further work is required to understand the mechanisms of these risk factors as well as mitigation strategies.

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Mandeep S. Tamber, John R. W. Kestle, Ron W. Reeder, Richard Holubkov, Jessica Alvey, Samuel R. Browd, James M. Drake, Abhaya V. Kulkarni, David D. Limbrick Jr., Patrick J. McDonald, Curtis J. Rozzelle, Tamara D. Simon, Robert Naftel, Chevis N. Shannon, John C. Wellons III, William E. Whitehead, Jay Riva-Cambrin, and for the Hydrocephalus Clinical Research Network

OBJECTIVE

Analysis of temporal trends in patient populations and procedure types may provide important information regarding the evolution of hydrocephalus treatment. The purpose of this study was to use the Hydrocephalus Clinical Research Network’s Core Data Project to identify meaningful trends in patient characteristics and the surgical management of pediatric hydrocephalus over a 9-year period.

METHODS

The Core Data Project prospectively collected patient and procedural data on the study cohort from 9 centers between 2008 and 2016. Logistic and Poisson regression were used to test for significant temporal trends in patient characteristics and new and revision hydrocephalus procedures.

RESULTS

The authors analyzed 10,149 procedures in 5541 patients. New procedures for hydrocephalus (shunt or endoscopic third ventriculostomy [ETV]) decreased by 1.5%/year (95% CI −3.1%, +0.1%). During the study period, new shunt insertions decreased by 6.5%/year (95% CI −8.3%, −4.6%), whereas new ETV procedures increased by 12.5%/year (95% CI 9.3%, 15.7%). Revision procedures for hydrocephalus (shunt or ETV) decreased by 4.2%/year (95% CI −5.2%, −3.1%), driven largely by a decrease of 5.7%/year in shunt revisions (95% CI −6.8%, −4.6%). Concomitant with the observed increase in new ETV procedures was an increase in ETV revisions (13.4%/year, 95% CI 9.6%, 17.2%). Because revisions decreased at a faster rate than new procedures, the Revision Quotient (ratio of revisions to new procedures) for the Network decreased significantly over the study period (p = 0.0363). No temporal change was observed in the age or etiology characteristics of the cohort, although the proportion of patients with one or more complex chronic conditions significantly increased over time (p = 0.0007).

CONCLUSIONS

Over a relatively short period, important changes in hydrocephalus care have been observed. A significant temporal decrease in revision procedures amid the backdrop of a more modest change in new procedures appears to be the most notable finding and may be indicative of an improvement in the quality of surgical care for pediatric hydrocephalus. Further studies will be directed at elucidation of the possible drivers of the observed trends.

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Mandeep S. Tamber, John R. W. Kestle, Ron W. Reeder, Richard Holubkov, Jessica Alvey, Samuel R. Browd, James M. Drake, Abhaya V. Kulkarni, David D. Limbrick Jr., Patrick J. McDonald, Curtis J. Rozzelle, Tamara D. Simon, Robert Naftel, Chevis N. Shannon, John C. Wellons III, William E. Whitehead, Jay Riva-Cambrin, and for the Hydrocephalus Clinical Research Network

OBJECTIVE

Analysis of temporal trends in patient populations and procedure types may provide important information regarding the evolution of hydrocephalus treatment. The purpose of this study was to use the Hydrocephalus Clinical Research Network’s Core Data Project to identify meaningful trends in patient characteristics and the surgical management of pediatric hydrocephalus over a 9-year period.

METHODS

The Core Data Project prospectively collected patient and procedural data on the study cohort from 9 centers between 2008 and 2016. Logistic and Poisson regression were used to test for significant temporal trends in patient characteristics and new and revision hydrocephalus procedures.

RESULTS

The authors analyzed 10,149 procedures in 5541 patients. New procedures for hydrocephalus (shunt or endoscopic third ventriculostomy [ETV]) decreased by 1.5%/year (95% CI −3.1%, +0.1%). During the study period, new shunt insertions decreased by 6.5%/year (95% CI −8.3%, −4.6%), whereas new ETV procedures increased by 12.5%/year (95% CI 9.3%, 15.7%). Revision procedures for hydrocephalus (shunt or ETV) decreased by 4.2%/year (95% CI −5.2%, −3.1%), driven largely by a decrease of 5.7%/year in shunt revisions (95% CI −6.8%, −4.6%). Concomitant with the observed increase in new ETV procedures was an increase in ETV revisions (13.4%/year, 95% CI 9.6%, 17.2%). Because revisions decreased at a faster rate than new procedures, the Revision Quotient (ratio of revisions to new procedures) for the Network decreased significantly over the study period (p = 0.0363). No temporal change was observed in the age or etiology characteristics of the cohort, although the proportion of patients with one or more complex chronic conditions significantly increased over time (p = 0.0007).

CONCLUSIONS

Over a relatively short period, important changes in hydrocephalus care have been observed. A significant temporal decrease in revision procedures amid the backdrop of a more modest change in new procedures appears to be the most notable finding and may be indicative of an improvement in the quality of surgical care for pediatric hydrocephalus. Further studies will be directed at elucidation of the possible drivers of the observed trends.