Browse

You are looking at 21 - 30 of 141 items for

  • Refine by Access: all x
  • By Author: Jea, Andrew x
Clear All
Full access

Zaid Aljuboori, Jacob Archer, Wei Huff, Amee Moreno, and Andrew Jea

Intrathecal baclofen has been suggested as an effective and safe treatment for intractable spasticity and dystonia. Techniques of lumbar and intraventricular catheter placement have been previously described. The purpose of this study was to describe a technique to implant catheters for intrathecal baclofen infusion through C1–2 puncture.

Four of 5 consecutively treated patients underwent successful placement of catheters for intrathecal baclofen. There were no instances of infection, CSF leak, or catheter migration seen during a follow-up period of at least 6 months; furthermore, there were no occurrences of vertebral artery or spinal cord injury. All patients had an effective stabilization or reduction of their upper-extremity, lower-extremity, or trunk tone. There were no cases of worsening hypertonia.

The authors’ preliminary experience with C1–2 puncture for placement of the intrathecal baclofen catheter seems to indicate that this is a safe and efficacious technique. Lessons learned from the failed attempt at C1–2 puncture will be delineated.

Full access

Jonathan N. Sellin, Jeffrey S. Raskin, Kristen A. Staggers, Alison Brayton, Valentina Briceño, Amee J. Moreno, and Andrew Jea

Thoracic and lumbar cortical bone trajectory pedicle screws have been described in adult spine surgery. They have likewise been described in pediatric CT-based morphometric studies; however, clinical experience in the pediatric age group is limited. The authors here describe the use of cortical bone trajectory pedicle screws in posterior instrumented spinal fusions from the upper thoracic to the lumbar spine in 12 children. This dedicated study represents the initial use of cortical screws in pediatric spine surgery.

The authors retrospectively reviewed the demographics and procedural data of patients who had undergone posterior instrumented fusion using thoracic, lumbar, and sacral cortical screws in children for the following indications: spondylolysis and/or spondylolisthesis (5 patients), unstable thoracolumbar spine trauma (3 patients), scoliosis (2 patients), and tumor (2 patients).

Twelve pediatric patients, ranging in age from 11 to 18 years (mean 15.4 years), underwent posterior instrumented fusion. Seventy-six cortical bone trajectory pedicle screws were placed. There were 33 thoracic screws and 43 lumbar screws. Patients underwent surgery between April 29, 2015, and February 1, 2016. Seven (70%) of 10 patients with available imaging achieved a solid fusion, as assessed by CT. Mean follow-up time was 16.8 months (range 13–22 months). There were no intraoperative complications directly related to the cortical bone trajectory screws. One patient required hardware revision for caudal instrumentation failure and screw-head fracture at 3 months after surgery.

Mean surgical time was 277 minutes (range 120–542 minutes). Nine of the 12 patients received either a 12- or 24-mg dose of recombinant human bone morphogenic protein 2. Average estimated blood loss was 283 ml (range 25–1100 ml).

In our preliminary experience, the cortical bone trajectory pedicle screw technique seems to be a reasonable alternative to the traditional trajectory pedicle screw placement in children. Cortical screws seem to offer satisfactory clinical and radiographic outcomes, with a low complication profile.

Full access

Kyung Shin Kang, Jeff Lastfogel, Laurie L. Ackerman, Andrew Jea, Alexander G. Robling, and Sunil S. Tholpady

OBJECTIVE

Cranial defects can result from trauma, infection, congenital malformations, and iatrogenic causes and represent a surgical challenge. The current standard of care is cranioplasty, with either autologous or allogeneic material. In either case, the intrinsic vascularity of the surrounding tissues allows for bone healing. The objective of this study was to determine if mechanotransductive gene manipulation would yield non–weight-bearing bone regeneration in a critical size calvarial defect in mice.

METHODS

A mouse model of Sost deletion in Sost knockout (KO) mice was created in which the osteocytes do not express sclerostin. A critical size calvarial defect (4 mm in diameter) was surgically created in the parietal bone in 8-week-old wild-type (n = 8) and Sost KO (n = 8) male mice. The defects were left undisturbed (no implant or scaffold) to simulate a traumatic calvariectomy model. Eight weeks later, the animals were examined at necropsy by planimetry, histological analysis of new bone growth, and micro-CT scanning of bone thickness.

RESULTS

Defects created in wild-type mice did not fill with bone over the study period of 2 months. Genetic downregulation of sclerostin yielded animals that were able to regenerate 40% of the initial critical size defect area 8 weeks after surgery. A thin layer of bone covered a significant portion of the original defect in all Sost KO animals. A statistically significant increase in bone volume (p < 0.05) was measured in Sost KO mice using radiodensitometric analysis. Immunohistochemical analysis also confirmed that this bone regeneration occurred through the Wnt pathway and originated from the edge of the defect; BMP signaling did not appear to be affected by sclerostin.

CONCLUSIONS

Mechanical loading is an important mechanism of bone formation in the cranial skeleton and is poorly understood. This is partially due to the fact that it is difficult to load bone in the craniomaxillofacial skeleton. This study suggests that modulation of the Wnt pathway, as is able to be done with monoclonal antibodies, is a potentially efficacious method for bone regeneration that requires further study.

Free access

Ali A. Baaj, Douglas Brockmeyer, Andrew Jea, and Amer F. Samdani

Free access

Thomas J. Gianaris, Ryan Nazar, Emily Middlebrook, David D. Gonda, Andrew Jea, and Daniel H. Fulkerson

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is a surgical alternative to placing a CSF shunt in certain patients with hydrocephalus. The ETV Success Score (ETVSS) is a reliable, simple method to estimate the success of the procedure by 6 months of postoperative follow-up. The highest score is 90, estimating a 90% chance of the ETV effectively treating hydrocephalus without requiring a shunt. Treatment with ETV fails in certain patients, despite their being the theoretically best candidates for the procedure. In this study the authors attempted to identify factors that further predicted success in patients with the highest ETVSSs.

METHODS

A retrospective review was performed of all patients treated with ETV at 3 institutions. Demographic, radiological, and clinical data were recorded. All patients by definition were older than 1 year, had obstructive hydrocephalus, and did not have a prior shunt. Failure of ETV was defined as the need for a shunt by 1 year. The ETV was considered a success if the patient did not require another surgery (either shunt placement or a repeat endoscopic procedure) by 1 year. A statistical analysis was performed to identify factors associated with success or failure.

RESULTS

Fifty-nine patients met the entry criteria for the study. Eleven patients (18.6%) required further surgery by 1 year. All of these patients received a shunt. The presenting symptom of lethargy statistically correlated with success (p = 0.0126, odds ratio [OR] = 0.072). The preoperative radiological finding of transependymal flow (p = 0.0375, OR 0.158) correlated with success. A postoperative larger maximum width of the third ventricle correlated with failure (p = 0.0265).

CONCLUSIONS

The preoperative findings of lethargy and transependymal flow statistically correlated with success. This suggests that the best candidates for ETV are those with a relatively acute elevation of intracranial pressure. Cases without these findings may represent the failures in this highly selected group.

Full access

Guillermo Aldave, Daniel Hansen, Steven W. Hwang, Amee Moreno, Valentina Briceño, and Andrew Jea

OBJECTIVE

Tethered cord syndrome is the clinical manifestation of an abnormal stretch on the spinal cord, presumably causing mechanical injury, a compromised blood supply, and altered spinal cord metabolism. Tethered cord release is the standard treatment for tethered cord syndrome. However, direct untethering of the spinal cord carries potential risks, such as new neurological deficits from spinal cord injury, a CSF leak from opening the dura, and retethering of the spinal cord from normal scar formation after surgery. To avoid these risks, the authors applied spinal column shortening to children and transitional adults with primary and secondary tethered cord syndrome and report treatment outcomes. The authors' aim with this study was to determine the safety and efficacy of spinal column shortening for tethered cord syndrome by analyzing their experience with this surgical technique.

METHODS

The authors retrospectively reviewed the demographic and procedural data of children and young adults who had undergone spinal column shortening for primary or secondary tethered cord syndrome.

RESULTS

Seven patients with tethered cord syndrome caused by myelomeningocele, lipomyelomeningocele, and transitional spinal lipoma were treated with spinal column shortening. One patient with less than 24 months of follow-up was excluded from further analysis. There were 3 males and 4 females; the average age at the time was surgery was 16 years (range 8–30 years). Clinical presentations for our patients included pain (in 5 patients), weakness (in 4 patients), and bowel/bladder dysfunction (in 4 patients). Spinal column osteotomy was most commonly performed at the L-1 level, with fusion between T-12 and L-2 using a pedicle screw-rod construct. Pedicle subtraction osteotomy was performed in 6 patients, and vertebral column resection was performed in 1 patient. The average follow-up period was 31 months (range 26–37 months). Computed tomography–based radiographic outcomes showed solid fusion and no instrumentation failure in all cases by the most recent follow-up. Five of 7 patients (71%) reported improvement in preoperative symptoms during the follow-up period. The mean differences in initial and most recent Scoliosis Research Society Outcomes Questionnaire and Oswestry Disability Index scores were 0.26 and –13%, respectively; minimum clinically important difference in SRS-22 and ODI were assumed to be 0.4% and –12.8%, respectively.

CONCLUSIONS

Spinal column shortening seems to represent a safe and efficacious alternative to traditional untethering of the spinal cord for tethered cord syndrome.

Full access

Guillermo Aldave, Daniel Hansen, Valentina Briceño, Thomas G. Luerssen, and Andrew Jea

OBJECTIVE

The authors previously demonstrated the use of a validated Objective Structured Assessment of Technical Skills (OSATS) tool for evaluating residents' operative skills in pediatric neurosurgery. However, no benchmarks have been established for specific pediatric procedures despite an increased need for meaningful assessments that can either allow for early intervention for underperforming trainees or allow for proficient residents to progress to conducting operations independently with more passive supervision. This validated methodology and tool for assessment of operative skills for common pediatric neurosurgical procedures—external ventricular drain (EVD) placement and shunt surgery— was applied to establish its procedure-based feasibility and reliability, and to document the effect of repetition on achieving surgical skill proficiency in pediatric EVD placement and shunt surgery.

METHODS

A procedure-based technical skills assessment for EVD placements and shunt surgeries in pediatric neurosurgery was established through the use of task analysis. The authors enrolled all residents from 3 training programs (Baylor College of Medicine, Houston Methodist Hospital, and University of Texas–Medical Branch) who rotated through pediatric neurosurgery at Texas Children's Hospital over a 26-month period. For each EVD placement or shunt procedure performed with a resident, the faculty and resident (for self-assessment) completed an evaluation form (OSATS) based on a 5-point Likert scale with 7 categories. Data forms were then grouped according to faculty versus resident (self) assessment, length of pediatric neurosurgery rotation, postgraduate year level, and date of evaluation (“beginning of rotation,” within 1 month of start date; “end of rotation,” within 1 month of completion date; or “middle of rotation”). Descriptive statistical analyses were performed with the commercially available SPSS statistical software package. A p value < 0.05 was considered statistically significant.

RESULTS

Five attending evaluators (including 2 fellows who acted as attending surgeons) completed 260 evaluations. Twenty house staff completed 269 evaluations for self-assessment. Evaluations were completed in 562 EVD and shunt procedures before the surgeons left the operating room. There were statistically significant differences (p < 0.05) between overall attending (mean 4.3) and junior resident (self; mean 3.6) assessments, and between overall attending (mean 4.8) and senior resident (self; mean 4.6) assessment scores on general performance and technical skills. The learning curves produced for the residents demonstrate a stereotypical U- or V-shaped curve for acquiring skills, with a significant improvement in overall scores at the end of the rotation compared with the beginning. The improvement for junior residents (Δ score = 0.5; p = 0.002) was larger than for senior residents (Δ score = 0.2; p = 0.018).

CONCLUSIONS

The OSATS is an effective assessment tool as part of a comprehensive evaluation of neurosurgery residents' performance for specific pediatric procedures. The authors observed a U-shaped learning curve, contradicting the idea that developing one's surgical technique and learning a procedure represents a monotonic, cumulative process of repetitions and improvement.

Full access

Ali H. Palejwala, Jared S. Fridley, Krystal Garcia, Sanjeev A. Vasudevan, David Khechoyan, Surya Rednam, Chester J. Koh, and Andrew Jea

Neurofibrosarcoma is rare in the pediatric age group. A malignant tumor of the sacrum presents significant challenges, especially if the goals are to resect with wide and clean surgical margins and to achieve acceptable functional outcomes. The authors report a case of this rare tumor affecting the sacrum and sacral nerve roots of a 7-year-old girl and review the role of total hemisacrectomy sparing the contralateral sacral nerve roots and lumbopelvic reconstruction in the treatment of this disease. This patient is, to the best of the authors' knowledge, the youngest to be treated in this manner.