Daniel H. Fulkerson

Endovascular retrograde suction decompression as an adjunct to surgical treatment of ophthalmic aneurysms: analysis of risks and clinical outcomes.

OBJECTIVE Endovascular retrograde suction decompression with balloon occlusion of the internal carotid artery is a useful adjunct in the surgical treatment of ophthalmic aneurysms. This technique helps establish proximal control, facilitates intraoperative angiography, and may aid dissection by evacuating blood and softening the aneurysm. Although the technical aspects of this procedure have been described, the published data on its safety are scant. This study analyzed 2 groups of patients who underwent craniotomies for treatment of ophthalmic aneurysms, comparing a group who received suction decompression with a group who did not. METHODS A retrospective analysis of prospectively collected data on 118 craniotomies for ophthalmic aneurysms performed from 1990 to 2005 is presented. A group of 63 patients treated with endovascular suction decompression during surgery is compared with 55 patients who did not undergo this technique. RESULTS In our overall analysis of ophthalmic aneurysms, the clinical outcome was statistically related to aneurysm size (P = 0.046). The endovascular suction decompression group in this study had overall larger aneurysms (P < 0.0001) compared with the other group. There was no statistical difference between the 2 groups in rates of complications, stroke, new visual deficit, or death. The clinical outcomes were statistically similar at discharge and at 1 year. CONCLUSION Endovascular balloon occlusion and suction decompression did not increase the complication rate in a large cohort of craniotomy patients with ophthalmic aneurysms. This technique may be used to augment surgical capabilities without significantly increasing the operative risk.

Analysis of the risk of shunt failure or infection related to cerebrospinal fluid cell count, protein level, and glucose levels in low-birth-weight premature infants with posthemorrhagic hydrocephalus

OBJECT Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. METHODS A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. RESULTS Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. CONCLUSIONS Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

Intraoperative monitoring of motor evoked potentials in very young children.

OBJECT Neurophysiological monitoring of motor evoked potentials (MEPs) during complex spine procedures may reduce the risk of injury by providing feedback to the operating surgeon. While this tool is a well-established surgical adjunct in adults, clinical data in children are sparse. The purpose of this study was to determine the reliability and safety of MEP monitoring in a group of children younger than 3 years of age undergoing neurosurgical spine procedures. METHODS A total of 10 consecutive spinal procedures in 10 children younger than 3 years of age (range 5-31 months, mean 16.8 months) were analyzed between January 1, 2008, and May 1, 2010. Motor evoked potentials were elicited by transcranial electric stimulation. A standardized anesthesia protocol for monitoring consisted of a titrated propofol drip combined with bolus dosing of fentanyl or sufentanil. RESULTS Motor evoked potentials were documented at the beginning and end of the procedure in all 10 patients. A mean baseline stimulation threshold of 533 ± 124 V (range 321-746 V) was used. Six patients maintained MEP signals ≥ 50% of baseline amplitude throughout the surgery. There was a greater than 50% decrease in intraoperative MEP amplitude in at least 1 extremity in 4 patients. Two of these patients returned to baseline status by the end of the case. Two patients had a persistent decrement or variability in MEP signals at the end of the procedure; this correlated with postoperative weakness. There were no complications related to the technique of monitoring MEPs. CONCLUSIONS A transcranial electric stimulation protocol monitoring corticospinal motor pathways during neurosurgical procedures in children younger than 3 years of age was reliably and safely implemented. A persistent intraoperative decrease of greater than 50% in this small series of 10 pediatric patients younger than 3 years of age predicted a postoperative neurological deficit. The authors advocate routine monitoring of MEPs in this pediatric age group undergoing neurosurgical spine procedures.

Risk of hemorrhage from de novo cerebral aneurysms.

OBJECT A small percentage of patients will develop a completely new or de novo aneurysm after discovery of an initial aneurysm. The natural history of these lesions is unknown. The authors undertook this statistical evaluation a large cohort of patients with both ruptured and unruptured de novo aneurysms with the aim of analyzing risk factors for rupture and estimating a risk of subarachnoid hemorrhage (SAH). METHODS A review of a prospectively maintained database of all aneurysm patients treated by the vascular neurosurgery service of Goodman Campbell Brain and Spine from 1976-2010 was performed. Of the 4718 patients, 611 (13%) had long-term follow-up imaging. The authors identified 27 patients (4.4%) with a total of 32 unruptured de novo aneurysms from routine surveillance imaging. They identified another 10 patients who presented with a new SAH from a de novo aneurysm after treatment of their original aneurysm. The total study group was thus 37 patients with a total of 42 de novo aneurysms. The authors then compared the 27 patients with incidentally discovered aneurysms with the 10 patients with SAH. A statistical analysis was performed, comparing the 2 groups with respect to patient and aneurysm characteristics and risk factors. RESULTS Thirty-seven patients were identified as having true de novo aneurysms. This group had a female predominance and a high percentage of smokers. These 37 patients had a total of 42 de novo aneurysms. Ten of these 42 aneurysms hemorrhaged. De novo aneurysms in both the SAH and non-SAH group were anatomically small (< 10 mm). The estimated risk of hemorrhage over 5 years was 14.5%, higher than the expected SAH risk of small, unruptured aneurysms reported in the ISUIA (International Study of Unruptured Intracranial Aneurysms) trial. There was no statistically significant correlation between hemorrhage and any of the following risk factors: hypertension, diabetes, tobacco and alcohol use, polycystic kidney disease, or previous SAH. There was a statistically significant between-groups difference with respect to patient age, with the mean patient age being significantly older in the SAH aneurysm group than in the non-SAH group (p = 0.047). This is likely reflective of longer follow-up and discovery time, as the mean length of time between initial treatment and discovery of the de novo aneurysm was longer in the SAH group (p = 0.011). CONCLUSIONS While rare, de novo aneurysms may have a risk for SAH that is comparatively higher than the risk associated with similarly sized, small, initially discovered unruptured saccular aneurysms. The authors therefore recommend long-term follow-up for all patients with aneurysms, and they consider a more aggressive treatment strategy for de novo aneurysms than for incidentally discovered initial aneurysms.

Fixation with C-2 laminar screws in occipitocervical or C1–2 constructs in children 5 years of age or younger: a series of 18 patients

UNLABELLED OBJECT.: There are rare indications for upper cervical spine fusion in young children. Compared with nonrigid constructs, rigid instrumentation with screw fixation increases the fusion rate and reduces the need for halo fixation. Instrumentation may be technically challenging in younger children. A number of screw placement techniques have been described. Use of C-2 translaminar screws has been shown to be anatomically feasible, even in the youngest of children. However, there are few data detailing the clinical outcome. In this study, the authors describe the clinical and radiographic follow-up of 18 children 5 years of age or younger who had at least one C-2 translaminar screw as part of an occipitocervical or C1-2 fusion construct. METHODS A retrospective review of all children treated with instrumented occipitocervical or C1-2 fusion between July 1, 2007, and June 30, 2013, at Riley Childrens Hospital and Texas Childrens Hospital was performed. All children 5 years of age or younger with incorporation of at least one C-2 translaminar screw were identified. RESULTS Eighteen children were studied (7 boys and 11 girls). The mean age at surgery was 38.1 months (range 10-68 months). Indications for surgery included traumatic instability (6), os odontoideum (3), destructive processes (2), and congenital instability (7). A total of 24 C-2 translaminar screws were placed; 23 (95.8%) of 24 were satisfactorily placed (completely contained within the cortical walls). There was one medial cortex breach without neurological impingement. There were no complications with screw placement. Three patients required wound revisions. Two patients died as a result of their original condition (trauma, malignant tumor). The mean follow-up duration for the surviving patients was 17.5 months (range 3-60 months). Eleven (91.7%) of the 12 patients followed for 6 months or longer showed radiographic stability or completed fusion. CONCLUSIONS Use of C-2 translaminar screws provides an effective anchor for internal fixation of the upper cervical spine. In this study of children 5 years of age or younger, the authors found a high rate of radiographic fusion with a low rate of complications.

Cerebrospinal fluid eosinophilia in children with ventricular shunts.

OBJECT Eosinophils have been reported in children with cerebrospinal fluid (CSF) shunts. The goal of this study was to describe the risk factors, relationship to infection, and clinical significance of CSF eosinophilia in a large group of shunt-treated patients. METHODS The authors performed a retrospective review of data obtained in all patients who underwent ventricular shunt placement or revision at the James Whitcomb Riley Hospital for Children between 2000 and 2004. RESULTS Eosinophils were identified during a follow-up shunt evaluation in 93 (31%) of 300 patients after initial shunt placement. Eosinophilia was statistically related to CSF extravasation (p < 0.0001), shunt infection (p = 0.031), blood in CSF (p < 0.0001), younger age at shunt insertion (p = 0.030), and the diagnosis of posthemorrhagic hydrocephalus (p < 0.0001). Patients with CSF eosinophilia had a higher risk of subsequent shunt failure (p < 0.0001). Analysis was performed using data obtained in a cohort of patients with a total of 130 shunt infections. Cerebrospinal fluid eosinophils were identified in 118 infections (90.8%). The leukocytic and eosinophilic reactions were dependent on the infecting organism. Propionibacterium acnes had a statistically lower CSF leukocyte count but higher differential percentage of eosinophils than the other common pathogens. CONCLUSIONS Cerebrospinal fluid eosinophilia is a relatively common finding in children with shunts. Patients with CSF eosinophilia had an increased risk of shunt malfunction in the present series. Eosinophilia is associated with infection, CSF extravasation, and blood in the CSF. Patients with P. acnes-induced shunt infections have higher eosinophil percentages than are found in infections associated with other common organisms. Therefore, in patients with eosinophilia, extended anaerobic culture studies should be performed with particular attention paid to searching for this pathogen.

Computed tomography morphometric analysis for translaminar screw fixation in the upper thoracic spine of the pediatric population

OBJECT Translaminar screw (TLS) fixation can be used safely and efficaciously for upper cervical fusion in children. No published studies have evaluated this technique in the thoracic spine of the pediatric population, and thus the authors undertook such an analysis. METHODS The upper thoracic spines (T1-4) of 130 patients, consisting of 70 boys and 60 girls, were studied using CT scans. Laminar height and thickness, screw length, and screw angle were measured. Exclusion criteria included the following: patients older than 18 years of age, trauma or congenital abnormalities of the thoracic spine, or absent demographic information or imaging studies through T-4. Statistical analysis was performed using paired or unpaired Student t-tests (p < 0.05) and linear regression analysis. RESULTS The mean laminar heights for T-1, T-2, T-3, and T-4 were as follows: 12.3 ± 3.4, 13.0 ± 3.5, 13.4 ± 3.8, and 14.7 ± 4.1 mm, respectively. The mean laminar widths were 6.5 ± 1.3, 6.6 ± 1.3, 6.6 ± 1.3, and 6.6 ± 1.4 mm, respectively. The mean screw lengths were 29.9 ± 4.1, 25.2 ± 3.5, 22.7 ± 3.2, and 21.6 ± 3.1 mm, respectively. The mean screw angles were 47° ± 4°, 48° ± 4°, 51° ± 4°, and 53° ± 5°, respectively. There were no significant differences between the right and left sides. However, significant differences were found when comparing patients younger than 8 years with those who were 8 years or older, and when comparing boys and girls. CONCLUSIONS Careful preoperative thin-cut CT with sagittal reconstruction is mandatory to determine if the placement of TLSs is feasible in the pediatric population. Based on CT analysis, the insertion of TLSs in the pediatric thoracic spine is possible in all patients older than 8 years and in many patients younger than 8 years. Boys could accept longer screws in the upper thoracic spine compared with girls.

Long-Term Follow-Up of Solitary Intracerebral Juvenile Xanthogranuloma

Juvenile xanthogranuloma is a benign, non-Langerhans-cell histiocytic infiltrate that typically presents as a solitary cutaneous lesion in childhood. There are reports of extracutanous involvement, including tumors in the central nervous system. A solitary, intraparenchymal tumor without skin manifestations is a rare event, with only 3 prior cases reported in the literature. Cerebral lesions have been associated with multifocal or systemic forms of the disease, with an occasionally fulminate clinical course. Considering the rarity of this tumor, it is unclear whether patients need adjuvant therapy after excision of a solitary intraparenchymal tumor. Previous reports suggested that complete excision of the lesion was curative; however long-term follow-up was not provided. This report illustrates a case of surgical excision of a solitary juvenile xanthogranuloma in an 8-year-old male with a 3-year follow-up period.

Progression of cerebrospinal fluid cell count and differential over a treatment course of shunt infection

OBJECT The physiological reaction of CSF white blood cells (WBCs) over the course of treating a shunt infection is undefined. The authors speculated that the CSF WBC count varies with different infecting organisms in peak level and differential percentage of polymorphonuclear (PMN) leukocytes, lymphocytes, monocytes, and eosinophils. The authors hope to identify clinically useful trends in the progression of CSF WBCs by analyzing a large group of patients with successfully treated shunt infections. METHODS The authors reviewed 105 successfully treated cases of shunt infections at Riley Hospital for Children. The study dates ranged from 2000 to 2004; this represented a period prior to the routine use of antibiotic-impregnated shunt catheters. They analyzed the following organisms: coagulase-negative staphylococci, Staphylococcus aureus, Propionibacterium acnes, Streptococcal species, and gram-negative organisms. The initial CSF sample at diagnosis was analyzed, as were levels over 14 days of treatment. Model fitting was performed to generate curves for the expected progression of the WBC counts and the differential PMN leukocytes, lymphocyte, monocyte, and eosinophil percentages. RESULTS Gram-negative organisms resulted in a higher initial (p = 0.03) and peak WBC count with a greater differential of PMN leukocytes compared with other organisms. Propionibacterium acnes infections were associated with a significantly lower WBC count and PMN leukocytes percentage (p = 0.02) and higher eosinophil percentage (p = 0.002) than other organisms. The pattern progression of the CSF WBC count and differential percentages was consistent for all infections. There was an initial predominance of PMN leukocytes, followed by a delayed peak of lymphocytes, monocytes, and eosinophils over a 14-day course. All values trended toward zero over the treatment course. CONCLUSIONS The initial and peak levels of CSF WBCs vary with the infecting organisms. The CSF cell counts showed a predictable pattern during the treatment of shunt infection. These trends may be useful to the physician in clinical decision making, although there is a wide range of variability.

Iliac screw placement in neuromuscular scoliosis using anatomical landmarks and uniplanar anteroposterior fluoroscopic imaging with postoperative CT confirmation.

OBJECT 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.