The authors describe rare cases of congenital hypoplasia of the L-5 pedicles and the congenital absence of the left S-1 pedicle in 2 young girls, respectively, including the presentation, diagnosis, and treatment. Moreover, they review the literature on this clinical entity. The patients presented with intractable chronic low-back pain. Plain radiographs and 2D CT scanning revealed the presence of the aforementioned anomalies. Degenerative changes to adjacent level and contralateral facet joints were thought to be the result of overload and instability and seemed to have led to spondylolisthesis, micromotion at L-5 and S-1, and subsequent low-back pain. The pediatric patients were treated with posterior instrumented fusion with good functional outcomes at a minimum 3-month follow-up. To the best of the authors' knowledge, these are the first reports of intractable low-back pain and spondylolisthesis accompanied by hypoplastic-aplastic pedicles at the lumbosacral junction in children.
Akash J. Patel, Sudhakar Vadivelu, Sohum K. Desai and Andrew Jea
Paul M. Arnold
Neurosurgical “pearls” and neurosurgical evidence
E. Antonio Chiocca
Joshua J. Chern, Akash J. Patel, Andrew Jea, Daniel J. Curry and Youssef G. Comair
Focal cortical dysplasia (FCD) is an important cause of intractable epilepsy and is at times treatable by resection. The now widespread use of MR imaging and recent advancement of functional imaging have increased the number of patients undergoing surgical treatment for FCD. The objective of this review is to critically examine and to provide a summary of surgical series on FCD published since 2000.
Studies concerning surgery for FCD were identified from MEDLINE and references of selected articles and book chapters. Data from these included studies were summarized and analyzed to identify factors correlated with seizure outcome.
Sixteen studies were identified, and 469 patients met our selection criteria. Seizure-free outcome at 1-year postoperatively was achieved in 59.7% of the patients. Children and adults were equally likely to benefit from the surgery. Complete resection (OR 13.7, 95% CI 6.68–28.1; p < 0.0001) and temporal location (OR 2.15, 95% CI 1.26–3.69; p = 0.0073) were two positive prognostic indicators of seizure-free outcome. Utilization of invasive monitoring did not affect the chance of seizure remission, but firm conclusions could not be drawn because patients were not randomized.
The advancement of modern imaging has transformed the process of surgical candidate selection for partial epilepsy due to FCD. Patients from recent surgical series were more homogeneous in their clinical presentations and might represent FCD as an independent pathological entity. This likely explained the improved surgical outcome for this group of patients. These reports also documented the increased utilization of functional imaging, but their efficacy needs to be verified with further studies.
Akash J. Patel, Ahilan Sivaganesan, Robert J. Bollo, Alison Brayton, Thomas G. Luerssen and Andrew Jea
Recent attempts to control health care costs focus on reducing or eliminating payments for complications, hospital-acquired conditions, and provider preventable conditions, with payment restrictions applied uniformly. A patient's preexisting comorbidities likely influence the perioperative complication incidence. This relationship has not previously been examined in pediatric neurosurgery.
The authors conducted a retrospective assessment of prospectively collected relevant patient comorbidities and morbidity and mortality events at a large pediatric neurosurgical unit over a 5-year period. The authors examined the impact of specific comorbidities and the cumulative effect of multiple comorbidities on complication incidence.
A total of 1990 patients underwent 3195 procedures at the authors' institution during the 5-year study period. Overall, 396 complications were analyzed; 298 patients (15.0%) experienced at least one complication. One or more comorbidities were present in 45.9% of patients. Renal comorbidities were clearly associated with the increased incidence of complications (p = 0.02), and they were specifically associated with infection (p = 0.006). Neurological comorbidities had a borderline association with complications (p = 0.05), and they were specifically associated with death (p = 0.037). A patient's having more comorbidities did not correlate with an increased risk of a perioperative complication (p = 0.8275).
The complication incidence in pediatric neurosurgery is variable and may be influenced by the type of neurosurgical procedure and patient-related factors. While patient-related factors beyond the control of the provider can significantly impact complications and hospital-acquired conditions in pediatric neurosurgery, an increasing number of comorbidities do not correlate with an increased risk of complications per patient.
Loyola V. Gressot, Akash J. Patel, Robert J. Bollo, Carrie A. Mohila and Andrew Jea
Juvenile xanthogranuloma (JXG) is a rare disease that is part of a spectrum of histiocytic dendritic cell disorders. The authors report an unusual case of a 6-week-old male who presented with seizures. Neuroimaging revealed disseminated intracranial disease involving the optic apparatus, basal ganglia, lateral ventricles, and brainstem. The patient did not have any cutaneous lesions or evidence of extracranial disease. The patient underwent open biopsy of a large right midbrain lesion; pathology was consistent with JXG. He underwent postoperative chemotherapy and is doing well 7 months after surgery with regression of the intracranial lesions. To the best of the authors' knowledge, this is the first report of a neonate with disseminated intracranial JXG without cutaneous stigmata.
Loyola V. Gressot, Akash J. Patel, Steven W. Hwang, Daniel H. Fulkerson and Andrew Jea
Neuromuscular scoliosis is a challenging pathology to treat. Surgical correction can involve long fusion constructs extending to the pelvis. The deformity inherent in these patients makes it difficult to obtain adequate lateral intraoperative radiographs for traditional image-guided placement of iliac screws.
A clinical and radiographic assessment of 14 patients with neuromuscular spinal deformity was conducted. From 2007 to 2013, 12 of these patients (mean age 14.25 years, range 10–20 years) underwent long spinal instrumentation (mean 15 levels, range 10–18 levels) and fusion to the pelvis, and 2 underwent placement of a growing rod construct with iliac screw placement at a single institution. The average length of follow-up was 33.7 months (range 6–64 months). Iliac screws were placed after identifying the posterior superior iliac spine and using only anteroposterior fluoroscopy (view of the inlet of the pelvis), rather than the technique of direct palpation of the sciatic notch. The accuracy of iliac screw placement was assessed with routine postoperative CT.
A total of 12 patients had 24 screws placed as part of a long-segment fusion to the pelvis, and 2 patients had two iliac screws placed as part of a growing rod construct for neuromuscular scoliosis. There were no iliac screw misplacements, and no complications directly related to the technique of iliac screw placement. For cases of definitive fusion (n = 12), the average coronal Cobb angle of patients with neuromuscular spinal deformity measured 62° before surgery and 44.3° immediately after surgery. The average preoperative thoracic kyphosis and lumbar sagittal lordosis measured 37.3° and 60.7°, respectively. Immediately after surgery, the thoracic and lumbar angles measured 30° and 41.1°, respectively. At last follow-up, the average coronal Cobb angle was maintained at 45.1°, and the thoracic and lumbar sagittal angles were maintained at 32.8° and 45.3°, respectively.
A less invasive technique for iliac screw placement can be performed safely with a low likelihood of screw misplacement. This technique offers the biomechanical advantages of iliac fixation without the soft tissue exposure typically needed for safe screw insertion. The technique relies on identification of the posterior superior iliac spine and high quality anteroposterior fluoroscopic imaging for a view of the pelvic inlet.
Dima Suki, Hiba Abouassi, Akash J. Patel, Raymond Sawaya, Jeffrey S. Weinberg and Morris D. Groves
The authors tested the hypothesis that patients with metastatic posterior fossa lesions (MPFLs) treated with resection have a higher risk of leptomeningeal disease (LMD) than those with MPFLs treated with stereotactic radiosurgery (SRS).
Between 1993 and 2004, 379 patients with MPFLs were treated with resection or SRS at The University of Texas M. D. Anderson Cancer Center. The authors' primary study outcome was the incidence of LMD, as diagnosed with cerebrospinal fluid cytological analysis and/or neuroimaging.
Resection was performed in 260 patients, whereas 119 patients underwent SRS. The median patient age was 56 years, 51% of patients were male, and 93% had a Karnofsky Performance Scale score $ 70. The most common primary cancers were those of the lung, breast, and kidney, as well as melanoma. Leptomeningeal dissemination of cancer occurred in 33 patients: 26 in the resection group and 7 in the SRS group (resection group: rate ratio [RR] 2.06, 95% confidence interval [CI] 0.89–4.75, p = 0.09). Piecemeal tumor resection (137 cases) was associated with a significantly higher risk of LMD than en bloc resection (123 cases; RR 3.4, 95% CI 1.43–8.12, p = 0.006) or SRS (RR 3.37, 95% CI 1.41–8.04, p = 0.006), and there was no significant difference in the risk for LMD between en bloc resection and SRS (en bloc resection: RR 0.98, 95% CI 0.34–2.81, p = 0.98). The multivariate RR and significance associated with piecemeal resection, however, were consistent, with a strong effect (RR 2.45, 95% CI 1.19–5.02, p = 0.02) and no indication of biases associated with tumor size, location, or cystic/necrotic appearance.
There is an increased risk of LMD after piecemeal resection of an MPFL. This increase, although clinically and statistically significant, is not as alarming as previously reported and is absent when en bloc removal is achieved. Further assessment of the role of resection in a controlled prospective setting is warranted.
George Al-Shamy, Jacob Cherian, Javier A. Mata, Akash J. Patel, Steven W. Hwang and Andrew Jea
Lateral mass screws are routinely placed throughout the subaxial cervical spine in adults, but there are few clinical or radiographic studies regarding lateral mass fixation in children. The morphology of pediatric cervical lateral masses may be associated with greater difficulty in obtaining adequate purchase. The authors examined the lateral masses of the subaxial cervical spine in pediatric patients to define morphometric differences compared with adults, establish guidelines for lateral mass instrumentation in children, and define potential limitations of this technique in the pediatric age group.
Morphometric analysis was performed on CT of the lateral masses of C3–7 in 56 boys and 14 girls. Measurements were obtained in the axial, coronal, and sagittal planes.
For most levels and measurements, results in boys and girls did not differ significantly; the few values that were significantly different are not likely to be clinically significant. On the other hand, younger (< 8 years of age) and older children (≥ 8 years of age) differed significantly at every level and measurement except for facet angularity. Sagittal diagonal, a measurement that closely estimates screw length, was found to increase at each successive caudal level from C-3 to C-7, similar to the adult population. A screw acceptance analysis found that all patients ≥ 4 years of age could accept at least a 3.5 × 10 mm lateral mass screw.
Lateral mass screw fixation is feasible in the pediatric cervical spine, particularly in children age 4 years old or older. Lateral mass screw fixation is feasible even at the C-7 level, where pedicle screw placement has been advised in lieu of lateral mass screws because of the small size and steep trajectory of the C-7 lateral mass. Nonetheless, all pediatric patients should undergo high-resolution, thin-slice CT preoperatively to assess suitability for lateral mass screw fixation.
Daniel H. Fulkerson, Steven W. Hwang, Akash J. Patel and Andrew Jea
External orthosis is the accepted and historical management of odontoid synchondrosis fractures; however, this conservative therapy carries a significant complication and fracture nonunion rate among young children. The purpose of this study was to evaluate the authors' own experience in the context of the literature, to explore surgical fixation as a primary treatment for unstable fractures. The authors retrospectively reviewed 2 cases of unstable odontoid synchondrosis fractures treated at their institution; both showed radiographic progression of deformity and subsequently underwent an open surgical reduction and fusion. A literature review was conducted to compare the authors' management strategy with those in published data. External orthosis for treatment of odontoid synchondrosis fractures has a strong history of success. However, in the literature, patients treated with a halo orthosis had a 43.3% rate of complications and an 11.4% risk of nonunion. There are radiographic findings that suggest instability, such as severe angulation and displacement of the odontoid process. Both patients in the present report underwent successful fusion without complication, as documented on CT scans obtained 3 months after surgery. Given the high rate of fusion attained with conservative therapy, it is recommended for most synchondrosis fractures. However, there is a recognized subgroup of synchondrosis fractures with severe angulation (> 30°) and displacement suggestive of significant ligamentous injury. In these patients, surgical fixation may be a safe and efficacious alternative to halo orthosis as the primary treatment.