Percutaneous/mini-laparotomy fetoscopic repair of open spina bifida: a novel surgical technique.

Open spina bifida is the most common congenital anomaly of the central nervous system compatible with life. Prenatal repair of open spina bifida via open maternal-fetal surgery has been shown to improve postnatal neurologic outcomes, including reducing the need for ventriculoperitoneal shunting and improving lower neuromotor function. Fetoscopic repair of open spina bifida minimizes the maternal risks while providing similar neurosurgical outcomes to the fetus. The following 2 fetoscopic techniques are currently in use: (1) the laparotomy-assisted approach, and (2) the percutaneous approach. The laparotomy-assisted fetoscopic technique appears to be associated with a lesser risk of preterm birth than the percutaneous approach. However, the percutaneous approach avoids laparotomy and uterine exteriorization and is associated with lesser anesthesia risk and improved maternal postsurgical recovery. The purpose of this article was to describe our experience with a modified surgical approach, which we call percutaneous/mini-laparotomy fetoscopy, in which access to the uterus for one of the ports is done via a mini-laparotomy, whereas the other ports are inserted percutaneously. This technique draws on the benefits of both the laparotomy-assisted and the percutaneous techniques while minimizing their drawbacks. This surgical approach may prove invaluable in the prenatal repair of open spina bifida and other complex fetal surgical procedures.

Ventricular access device infection rate: a retrospective study and review of the literature.

PURPOSE: Ventricular access devices (VAD) are often used for treatment of posthemorrhagic hydrocephalus (PHH) in preterm infants. The reported rates of infection have varied and range from 0 to 22 %. The objective of our study is to present our VAD associated infection at our institution. METHODS: The charts for patients that had VADs inserted between May 1, 2009 and October 31, 2013 at a single institution (Children's Healthcare of Atlanta) were retrospectively reviewed. The number of VAD infections, defined as either cerebrospinal fluid (CSF)-positive cultures or wound complication, was recorded. Of patients that survived, the number of VAD to shunt conversions was also examined. The data from 15 previously published studies were pooled to determine overall VAD infection and VAD to shunt conversion rates. RESULTS: A total of 142 VADs were placed. There were 13 infections (9.2 %), 11 of which had CSF-positive cultures (7.7 %). There were two wound complications with negative CSF cultures. Six patients died after VAD placement for reasons unrelated to their VAD surgeries (4.2 %). In the remaining patients, there were 113 VAD to shunt conversions (83.1 %). Fifteen studies that reported VAD infections were analyzed; an overall infection rate of 7.0 % and VAD to shunt conversion rate of 79 % were calculated. CONCLUSIONS: While VAD is a valuable tool to treat PHH, it remains a procedure with an infection rate between 7.0 and 8.0 %. Close follow-up is needed to capture these adverse events as early as possible. Approximately 80 % of patients with PHH will require permanent CSF diversion.

Shunt timing in low-weight infants in the treatment of hydrocephalus.

OBJECTIVE: The optimal timing of ventricular shunt placement in low-weight and preterm infants remains an unresolved topic in modern pediatric neurosurgery. Shunt placement for hydrocephalus is performed over a wide range of infant weights, and the standard weight threshold for shunt placement can vary substantially across institutions. The aim of this study was to investigate shunt outcome in infants of low body weight. METHODS: An IRB-approved retrospective analysis of 76 infants (29 females, 47 males) who received primary shunt placement between 2003 and 2018 was performed. Uniform criteria were used over the entire dataset to determine the safety for ventriculoperitoneal (VP) shunt placement: 1) weight near or above 1500 g, 2) feeding tolerance, and 3) lack of necrotizing enterocolitis or active systemic infection. Infants were classified into a low-weight (LW) (< 2000 g) or standard weight (SW) (2000-3000 g) group based on their body weight at the time of initial shunt placement. Shunt survival was compared between the groups. The threshold weight separating the LW and SW groups and outcomes was additionally varied and systematically reanalyzed. RESULTS: Shunts were placed in 24 LW infants and 52 SW infants over the inclusion period. Etiologies for hydrocephalus were similar across groups: predominantly intraventricular hemorrhage (54%) (p = 0.13) and open neural tube defect (29%) (p = 0.61). Both LW and SW groups had 58% 1-year shunt survival rates. Overall, 46% of shunts failed in the LW group compared with 54% in the SW group over a median follow-up of 47 months (range 0-170 months). A log-rank test comparing shunt survival rates did not show significance (p = 0.43). Groups were repartitioned using a range of threshold weights (1600-2400 g) to divide LW from SW infants. The lack of association between VP shunt placement in LW infants and time frame of revision was consistently observed over the full range of varied threshold weights. CONCLUSIONS: There was no significant difference in overall time to shunt revision between infants weighing < 2000 g and infants weighing 2000-3000 g. No correlation between weight and shunt survival was detected. Combined with other clinical features pertinent to the management of hydrocephalus in the neonatal population, this investigation provides insight toward clinical decision-making regarding infants of low birth weight and suggests that further multi-institutional study on this topic is warranted.

Incidental dural tears during pediatric posterior spinal fusions.

PURPOSE: To characterize the frequency of incidental dural tears in pediatric spine surgery, their treatment, complications, and results of long-term follow-up. METHODS: A retrospective review of all pediatric patients who underwent a posterior spinal fusion (PSF) between 2004-2019 at a tertiary children's hospital was conducted. Electronic medical records were reviewed for patient demographics, intra-operative data, presence of an incidental dural tear, repair method, and patient outcomes. RESULTS: 3043 PSFs were reviewed, with 99 dural tears identified in 94 patients (3.3% overall incidence). Mean follow-up was 35.7 months (range 0.1-142.5). When the cause of the dural tear was specified, 69% occurred during exposure, 5% during pedicle screw placement, 4% during osteotomy, 2% during removal of implants, and 2% during intra-thecal injection of morphine. The rate of dural tears during primary PSF was significantly lower than during revision PSF procedures (2.6% vs. 6.2%, p < 0.05). 86.9% of dural tears were repaired and/or sealed intraoperatively, while 13.1% had spontaneous resolution. Postoperative headaches developed in 13.1% of patients and resolved at a mean of 7.6 days. There was no difference in the incidence of headaches in patients that were ordered bedrest vs. no bedrest (p > 0.99). Postoperative infections occurred in 9.5% of patients and 24.1% patients were identified to have undergone a revision surgery. CONCLUSIONS: Incidence of intra-operative dural tears in pediatric spine surgery is 3.3%. Although complications associated with the dural tear occur, most resolve over time and there were no long-term sequelae in patients with 2 years of follow up. LEVEL OF EVIDENCE: Level IV.

Surgical management of pediatric spinal aneurysmal bone cysts: patient series.

BACKGROUND: Aneurysmal bone cysts (ABCs) are rare, highly vascular osteolytic bone lesions that predominantly affect pediatric populations. This report evaluates the clinicopathological data of pediatric patients with spinal ABCs. The medical records for all patients at Children's Hospital Los Angeles with biopsy-proven ABCs of the spine between 1998 and 2018 were evaluated. OBSERVATIONS: Seventeen patients, 6 males and 11 females, were identified. The mean age at surgery was 10.4 years (range, 3.5-20 years). The most common presenting complaint was pain at the lesion site 16/17 (94%), followed by lower-extremity weakness 8/17 (47%). Resection and intralesional curettage were performed in all patients. Three (18%) of 17 patients underwent selective arterial embolization prior to resection. Spinal stability was compromised in 15 of 17 patients (88%), requiring instrumented fusion. Five (29%) of the 17 patients received additional therapy including radiation, calcitonin-methylprednisolone, or phenol. Four (23.5%) of 17 patients experienced a recurrence, and the mean time to recurrence was 15 months. The postoperative follow-up ranged from 6 to 108 months (median, 28 months). Reoperation occurred after an average of 35 months. At the recent follow-up, patients were free of disease. LESSONS: Gross-total resection by intralesional curettage with case-dependent instrumented spinal fusion for instability remains an effective strategy for managing pediatric spinal ABCs. Long-term follow-up is necessary to detect tumor recurrence.

Supracerebellar infratentorial resection of a torcular lesion causing fulminant intracranial hypertension: illustrative case.

BACKGROUND: Venous sinus stenosis has been implicated in intracranial hypertension and can lead to papilledema and blindness. The authors report the unique case of a cerebellar transtentorial lesion resulting in venous sinus stenosis in the torcula and bilateral transverse sinuses that underwent resection. OBSERVATIONS: A 5-year-old male presented with subacute vision loss and bilateral papilledema. Imaging demonstrated a lesion causing mass effect on the torcula/transverse sinuses and findings of increased intracranial pressure (ICP). A lumbar puncture confirmed elevated pressure, and the patient underwent bilateral optic nerve sheath fenestration. Cerebral angiography and venous manometry showed elevated venous sinus pressures suggestive of venous hypertension. The patient underwent a craniotomy and supracerebellar/infratentorial approach. A stalk emanating from the cerebellum through the tentorium was identified and divided. Postoperative magnetic resonance imaging showed decreased lesion size and improved sinus patency. Papilledema resolved and other findings of elevated ICP improved. Pathology was consistent with atrophic cerebellar cortex. Serial imaging over 6 months demonstrated progressive decrease in the lesion with concurrent improvements in sinus patency. LESSONS: Although uncommon, symptoms of intracranial hypertension in patients with venous sinus lesions should prompt additional workup ranging from dedicated venous imaging to assessments of ICP and venous manometry.

Transient Complete Resolution of Tourette Syndrome Symptoms Following Personalized Depth Electrode Placement.

Treatment refractory Tourette syndrome has been shown to be improved with deep brain stimulation, but with multiple possible stimulation locations and variable and incomplete benefit. This study presents a single case of complete amelioration of motor and verbal tics in a patient with Tourette syndrome during placement of 12 stereo-EEG electrodes to identify optimal targets for permanent stimulating electrodes. Subsequently, substantial improvement in motor and verbal tic frequency occurred with placement and programming of permanent electrodes in bilateral globus pallidus internus and nucleus accumbens, but without the complete resolution seen during depth electrode placement. We suggest that simultaneous stimulation at multiple patient-specific targets could provide effective control of Tourette symptomatology, but further study will be needed.

Fetal blood gases after in utero carbon dioxide insufflation for percutaneous fetoscopic spina bifida repair.

BACKGROUND: Prenatal repair of open spina bifida via the percutaneous fetoscopic approach does not require maternal laparotomy, hysterotomy, or exteriorization of the uterus. This technique requires intrauterine partial CO2 insufflation. Limited data exist on the physiological effects of CO2 insufflation on human fetuses, with no data on open spina bifida repair performed using the entirely percutaneous fetoscopic surgical technique. OBJECTIVE: Our aim was to examine the effects of intrauterine partial CO2 insufflation on fetal blood gases after percutaneous fetoscopic open spina bifida repair. STUDY DESIGN: This was a prospective study of patients who underwent percutaneous fetoscopic open spina bifida repair from February 2019 to July 2020. Fetal cordocentesis of the umbilical vein was performed in cases with favorable access to the umbilical cord. The umbilical vein cord blood samples were obtained under ultrasound guidance immediately at the conclusion of the open spina bifida repair. Simultaneous maternal arterial blood gas samples were also obtained. The results are reported as median (range). RESULTS: Of the 20 patients who underwent percutaneous fetoscopic open spina bifida repair during the study period, 7 patients (35%) underwent fetal blood sampling. The gestational age at the time of surgery was 27.4 (24.0-27.9) weeks and the operative time was 183 (156-251) minutes. The CO2 exposure time was 122 (57-146) minutes with maximum pressure of 13.5 (12.0-15.0) mm Hg. Fetal umbilical vein results were as follows: pH 7.35 (7.30-7.39), partial pressure of O2 56.2 (47.1-99.9) mm Hg, partial pressure of CO2 43.8 (36.2-53.0) mm Hg, HCO3 23.9 (20.1-25.6) mmol/L, and base excess -2.2 (-4.5 to -0.4) mmol/L. Simultaneous maternal arterial blood gas results were as follows: pH 7.37 (7.28-7.42), partial pressure of O2 187.5 (124.4-405.2) mm Hg, partial pressure of CO2 36.6 (30.7-46.0) mm Hg, HCO3 21.3 (18.0-22.8) mmol/L and base excess -3.2 (-5.9 to -1.8) mmol/L. CONCLUSION: Despite prolonged CO2insufflation of the uterus, fetal umbilical vein pH and base excess values did not approach those associated with potentially pathologic fetal acidemia.

Postoperative facial palsy after pediatric posterior fossa tumor resection.

OBJECTIVE: Facial palsy can be caused by masses within the posterior fossa and is a known risk of surgery for tumor resection. Although well documented in the adult literature, postoperative facial weakness after posterior fossa tumor resection in pediatric patients has not been well studied. The objective of this work was to determine the incidence of postoperative facial palsy after tumor surgery, and to investigate clinical and radiographic risk factors. METHODS: A retrospective analysis was conducted at a single large pediatric hospital. Clinical, radiographic, and histological data were examined in children who were surgically treated for posterior fossa tumors between May 1, 1994, and June 1, 2011. The incidence of postoperative facial weakness was documented. A multivariate logistic regression model was used to analyze the predictive ability of clinicoradiological variables for facial weakness. RESULTS: A total of 163 patients were included in this study. The average age at surgery was 7.4 ± 4.7 years, and tumor pathologies included astrocytoma (44%), medulloblastoma (36%), and ependymoma (20%). The lesions of 27 patients (17%) were considered high grade in nature. Thirteen patients (8%) exhibited preoperative symptoms of facial palsy. The overall incidence of postoperative facial palsy was 26% (43 patients), and the incidence of new postoperative facial palsy in patients without preoperative facial weakness was 20% (30 patients). The presence of a preoperative facial palsy had a large and significant effect in univariate analysis (OR 11.82, 95% CI 3.07-45.44, p < 0.01). Multivariate logistic regression identified recurrent operation (OR 4.45, 95% CI 1.49-13.30, p = 0.01) and other preoperative cranial nerve palsy (CNP; OR 3.01, 95% CI 1.24-7.29, p = 0.02) as significant risk factors for postoperative facial weakness. CONCLUSIONS: Facial palsy is a risk during surgical resection of posterior fossa brain tumors in the pediatric population. The study results suggest that the incidence of new postoperative facial palsy can be as high as 20%. The presence of preoperative facial palsy, an operation for recurrent tumor, and the presence of other preoperative CNPs were found to be significant risk factors for postoperative facial weakness.

Resolution of neonatal posthemorrhagic ventricular dilation coincident with patent ductus arteriosus ligation: case report.

Preterm infants commonly present with a hemodynamically significant patent ductus arteriosus (hsPDA). The authors describe the case of a preterm infant with posthemorrhagic ventricular dilation, which resolved in a temporally coincident fashion to repair of hsPDA. The presence of a PDA with left-to-right shunting was confirmed at birth on echocardiogram and was unresponsive to repeated medical intervention. Initial cranial ultrasound revealed periventricular-intraventricular hemorrhage. Follow-up serial ultrasound showed resolving intraventricular hemorrhage and progressive bilateral hydrocephalus. At 5 weeks, the ductus was ligated with the goal of improving hemodynamic stability prior to CSF diversion. However, neurosurgical intervention was not required due to improvement of ventriculomegaly occurring immediately after PDA ligation. No further ventricular dilation was observed at the 6-month follow-up.Systemic venous flow disruption and abnormal patterns of cerebral blood circulation have been previously associated with hsPDA. Systemic hemodynamic change has been reported to follow hsPDA ligation, although association with ventricular normalization has not. This case suggests that the unstable hemodynamic environment due to left-to-right shunting may also impede CSF outflow and contribute to ventriculomegaly. The authors review the literature surrounding pressure transmission between a PDA and the cerebral vessels and present a mechanism by which PDA may contribute to posthemorrhagic ventricular dilation.

Variation in hospital charges in patients with external ventricular drains: comparison between the intensive care and surgical floor settings.

OBJECTIVE: Placement of an external ventricular drain (EVD) is a common and potentially life-saving neurosurgical procedure, but the economic aspect of EVD management and the relationship to medical expenditure remain poorly studied. Similarly, interinstitutional practice patterns vary significantly. Whereas some institutions require that patients with EVDs be monitored strictly within the intensive care unit (ICU), other institutions opt primarily for management of EVDs on the surgical floor. Therefore, an ICU burden for patients with EVDs may increase a patient's costs of hospitalization. The objective of the current study was to examine the expense differences between the ICU and the general neurosurgical floor for EVD care. METHODS: The authors performed a retrospective analysis of data from 2 hospitals within a single, large academic institution-the University of Washington Medical Center (UWMC) and Seattle Children's Hospital (SCH). Hospital charges were evaluated according to patients' location at the time of EVD management: SCH ICU, SCH floor, or UWMC ICU. Daily hospital charges from day of EVD insertion to day of removal were included and screened for days that would best represent baseline expenses for EVD care. Independent-samples Kruskal-Wallis analysis was performed to compare daily charges for the 3 settings. RESULTS: Data from a total of 261 hospital days for 23 patients were included in the analysis. Ten patients were cared for in the UWMC ICU and 13 in the SCH ICU and/or on the SCH neurosurgical floor. The median values for total daily hospital charges were $19,824.68 (interquartile range [IQR] $12,889.73-$38,494.81) for SCH ICU care, $8,620.88 (IQR $6,416.76-$11,851.36) for SCH floor care, and $10,002.13 (IQR $8,465.16-$12,123.03) for UWMC ICU care. At SCH, it was significantly more expensive to provide EVD care in the ICU than on the floor (p < 0.001), and the daily hospital charges for the UWMC ICU were significantly greater than for the SCH floor (p = 0.023). No adverse clinical event related to the presence of an EVD was identified in any of the settings. CONCLUSIONS: ICU admission solely for EVD care is costly. If safe EVD care can be provided outside of the ICU, it would represent a potential area for significant cost savings. Identifying appropriate patients for EVD care on the floor is multifactorial and requires vigilance in balancing the expenses associated with ICU utilization and optimal patient care.

Minimally Invasive Tubular Tethered Cord Release in the Pediatric Population.

BACKGROUND: Tethered cord syndrome (TCS) refers to a clinical constellation of signs and symptoms associated with tension in the spinal cord and associated with pathologies related to abnormally low-lying conus medullaris. As minimally invasive spinal operations have become more prevalent in the past decade, we applied expanding indications to selected intradural procedures, such as tethered cord release (TCR). We present the first series of minimally invasive muscle-sparing TCR in the pediatric population. METHODS: A retrospective review of the Texas Children's Hospital, Houston, neurosurgical database was conducted for patients who underwent TCR between 2010 and 2017. Charts were reviewed to determine the source of TCS and whether surgery was conducted in a minimally invasive fashion. To establish a cohort of control population, age-matched cases of open TCR were selected in the same. Exclusion criterion was non-fatty filum sources of TCS. The length of stay, operative time, estimated blood loss, and postoperative complications were recorded. RESULTS: Eleven patients underwent minimally invasive TCR. Mean age of the patients was 10.1 years. All patients underwent L4-5 tubular laminotomy and cord detethering by 2 pediatric neurosurgeons at Texas Children's Hospital. The average length of stay in the hospital was 2.6 days. The average operative time was 167 minutes and average estimated blood loss was 8.2 mL. Ten patients reported clinical improvement and 1 patient was lost to follow-up. CONCLUSIONS: Minimally invasive TCR is a safe and represents a viable alternative to the open approach with advantages such as minimal estimated blood loss, shortened length of stay, and postoperative pain control.

Early Cranioplasty is Associated with Greater Neurological Improvement: A Systematic Review and Meta-Analysis.

BACKGROUND: Cranioplasty after decompressive craniectomy is a common neurosurgical procedure, yet the optimal timing of cranioplasty has not been well established. OBJECTIVE: To investigate whether the timing of cranioplasty is associated with differences in neurological outcome. METHODS: A systematic literature review and meta-analysis was performed using MEDLINE, Scopus, and the Cochrane databases for studies reporting timing and neurological assessment for cranioplasty after decompressive craniectomy. Pre- and postcranioplasty neurological assessments for cranioplasty performed within (early) and beyond (late) 90 d were extracted. The standard mean difference (SMD) was used to normalize all neurological measures. Available data were pooled to compare pre-cranioplasty, postcranioplasty, and change in neurological status between early and late cranioplasty cohorts, and in the overall population. RESULTS: Eight retrospective observational studies were included for a total of 528 patients. Studies reported various outcome measures (eg, Barthel Index, Karnofsky Performance Scale, Functional Independence Measure, Glasgow Coma Scale, and Glasgow Outcome Score). Cranioplasty, regardless of timing, was associated with significant neurological improvement (SMD .56, P = .01). Comparing early and late cohorts, there was no difference in precranioplasty neurological baseline; however, postcranioplasty neurological outcome was significantly improved in the early cohort (SMD .58, P = .04) and showed greater magnitude of change (SMD 2.90, P = .02). CONCLUSION: Cranioplasty may improve neurological function, and earlier cranioplasty may enhance this effect. Future prospective studies evaluating long-term, comprehensive neurological outcomes will be required to establish the true effect of cranioplasty on neurological outcome.

Percutaneous Instrumentation Without Arthrodesis for Thoracolumbar Flexion-Distraction Injuries: A Review of the Literature.

Background: Flexion-distraction injuries (FDI) represent 5% to 15% of traumatic thoracolumbar fractures. Treatment depends on the extent of ligamentous involvement: osseous/Magerl type B2 injuries can be managed conservatively, while ligamentous/Magerl type B1 injuries undergo stabilization with arthrodesis. Minimally invasive surgery without arthrodesis can achieve similar outcomes to open procedures. This has been studied for burst fractures; however, its role in FDI is unclear. Objective: To conduct a systematic review of the literature that examined minimally invasive surgery instrumentation without arthrodesis for traumatic FDI of the thoracolumbar spine. Methods: Four electronic databases were searched, and articles were screened using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines for patients with traumatic FDI of the thoracolumbar spine treated with percutaneous techniques without arthrodesis and had postoperative follow-up. Results: Seven studies with 44 patients met inclusion criteria. There were 19 patients with osseous FDI and 25 with ligamentous FDI. When reported, patients (n = 39) were neurologically intact preoperatively and at follow-up. Osseous FDI patients underwent instrumentation at 2 levels, while ligamentous injuries at approximately 4 levels. Complication rate was 2.3%. All patients had at least 6 mo of follow-up and demonstrated healing on follow-up imaging. Conclusion: Percutaneous instrumentation without arthrodesis represents a low-risk intermediate between conservative management and open instrumented fusion. This "internal bracing" can be used in osseous and ligamentous FDIs. Neurologically intact patients who do not require decompression and those that may not tolerate or fail conservative management may be candidates. The current level of evidence cannot provide official recommendations and future studies are required to investigate long-term safety and efficacy.

Cranioplasty Infection and Resorption Are Associated with the Presence of a Ventriculoperitoneal Shunt: A Systematic Review and Meta-Analysis.

BACKGROUND: Following decompressive craniectomy, hydrocephalus is a common complication often necessitating placement of a ventriculoperitoneal shunt (VPS). Complications in the presence of a VPS have been reported, but a clear association has not been established. METHODS: PRISMA guidelines were used to perform a literature search using PubMed to identify articles that published the complication rates associated with staged or simultaneous cranioplasty and VPS placement. From these event rates, odds ratios (ORs) with 95% confidence intervals (CIs) of complications were calculated. Data were pooled using the Mantel-Haenszel method. The Oxford Center for Evidence-Based Medicine guidelines were used to assess the quality of individual articles and studies. The Newcastle-Ottawa Scale was used to assess the risk of bias in studies. RESULTS: Of the 30 papers reviewed for complications in the presence and absence of a VPS, 7 studies, with a total of 1635 patients, were eligible for meta-analysis. Overall rates of complications (n = 1635; OR, 9.75; 95% CI, 4.8-20.1), infection (OR, 4.9; 95% CI, 2.2-10.7), and bone resorption (OR, 10.6; 95% CI, 4.9-23.0) were increased when a VPS was placed at the time of cranioplasty. Simultaneous procedures were associated with increased complication rates (n = 283; OR, 4.3; 95% CI, 2.3-8.2) compared with staged procedures. CONCLUSIONS: Cranioplasty in the presence of a VPS is associated with a higher rate of overall complications, including infection and bone resorption. Performing cranioplasty and VPS placement in the same operation is associated with an increased rate of complications compared with staged procedures. Surgeons should consider staging these procedures when possible and counsel patients about these risks.

Spinal Diffusion Tensor Imaging in Evaluation of Preoperative and Postoperative Severity of Cervical Spondylotic Myelopathy: Systematic Review of Literature.

BACKGROUND: Diffusion tensor imaging (DTI) is increasingly investigated as a potential diagnostic and prognostic tool for symptomatic degenerative cervical pathology; however, it is yet to be validated for this purpose. OBJECTIVE: To investigate the association of preoperative DTI signal changes and postoperative outcomes in patients with cervical spondylotic myelopathy (CSM). METHODS: We performed a systematic literature review using PubMed for clinical studies using DTI in adults undergoing operative management for CSM. Data on preoperative clinical status, preoperative DTI metrics, and postoperative clinical outcomes were abstracted. Preoperative DTI parameters were correlated with preoperative severity and postoperative outcomes and pooled across studies. RESULTS: Nine studies met inclusion criteria for 238 patients who underwent operative management with mean follow-up time 310 days. Higher preoperative fractional anisotropy (FA) at the level of maximal compression correlates strongly with a higher preoperative modified Japanese Orthopaedic Association (mJOA) score (n = 192 patients, rho = 0.62, P < 0.001). Higher preoperative FA is associated with less postoperative mJOA change (n = 27, rho = -0.42, P = 0.02) but a greater recovery rate (n = 93, rho = 0.32, P < 0.001). Preoperative FA correlated with lower Neck Disability Index (n = 15, rho = -0.61, P = 0.04). Preoperative fiber tract ratio had a large positive correlation with a postoperative recovery rate (n = 20, rho = 0.61, P = 0.005). When reported, an apparent diffusion coefficient showed an inverse correlation compared with FA. CONCLUSION: DTI is associated with preoperative severity and postoperative outcomes in CSM patients, suggesting that DTI may become useful in identifying those most likely to benefit from operative intervention (Level 3 Evidence). Prospective trials with standardized DTI acquisition techniques and patient selection are required for higher-level evidence.

Effects of Cranioplasty on Cerebral Blood Flow Following Decompressive Craniectomy: A Systematic Review of the Literature.

BACKGROUND: Cranioplasty after decompressive craniectomy (DC) is routinely performed for reconstructive purposes and has been recently linked to improved cerebral blood flow (CBF) and neurological function. OBJECTIVE: To systematically review all available literature to evaluate the effect of cranioplasty on CBF and neurocognitive recovery. METHODS: A PubMed, Google Scholar, and MEDLINE search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines included studies reporting patients who underwent DC and subsequent cranioplasty in whom cerebral hemodynamics were measured before and after cranioplasty. RESULTS: The search yielded 21 articles with a total of 205 patients (range 3-76 years) who underwent DC and subsequent cranioplasty. Two studies enrolled 29 control subjects for a total of 234 subjects. Studies used different imaging modalities, including CT perfusion (n = 10), Xenon-CT (n = 3), single-photon emission CT (n = 2), transcranial Doppler (n = 6), MR perfusion (n = 1), and positron emission tomography (n = 2). Precranioplasty CBF evaluation ranged from 2 days to 6 months; postcranioplasty CBF evaluation ranged from 7 days to 6 months. All studies demonstrated an increase in CBF ipsilateral to the side of the cranioplasty. Nine of 21 studies also reported an increase in CBF on the contralateral side. Neurological function improved in an overwhelming majority of patients after cranioplasty. CONCLUSION: This systematic review suggests that cranioplasty improves CBF following DC with a concurrent improvement in neurological function. The causative impact of CBF on neurological function, however, requires further study.

Repair of a traumatic subarachnoid-pleural fistula with the percutaneous injection of fibrin glue in a 2-year-old.

Subarachnoid-pleural fistulas (SPFs) are rare clinical entities that occur after severe thoracic trauma or iatrogenic injury during anterolateral approaches to the spine. Treatment of these fistulas often entails open repair of the dural defect. The authors present the case of an SPF in a 2-year-old female after a penetrating injury to the chest. The diagnosis of an SPF was suspected given the high chest tube output and was confirmed with a positive ß2-transferrin test of the chest tube fluid, as well as visualization of dural defects on MRI. The dural defects were successfully repaired with CT-guided percutaneous epidural injection of fibrin glue alone. This case represents the youngest pediatric patient with a traumatic SPF to be treated percutaneously. This technique can be safely used in pediatric patients, offers several advantages over open surgical repair, and could be considered as an alternative first-line therapy for the obliteration of SPFs.

Complications following cranioplasty and relationship to timing: A systematic review and meta-analysis.

The optimal timing of cranioplasty after decompressive craniectomy has not been well established. The purpose of this study was to evaluate the relationship between timing of cranioplasty and related complications. A systematic search of MEDLINE, Scopus, and the Cochrane databases was performed using PRISMA guidelines for English-language articles published between 1990 and 2015. Case series, case-control and cohort studies, and clinical trials reporting timing and complication data for cranioplasty after decompressive craniectomy in adults were included. Extracted data included overall complications, infections, reoperations, intracranial hemorrhage, extra-axial fluid collections, hydrocephalus, seizures, and bone resorption for cranioplasty performed within (early) and beyond (late) 90days. Twenty-five of 321 articles met inclusion criteria for a total of 3126 patients (1421 early vs. 1705 late). All were retrospective observational studies. Early cranioplasty had significantly higher odds of hydrocephalus than late cranioplasty (Odds Ratio [OR] 2.38, 95% Confidence Interval [CI] 1.25-4.52, p=0.008). There was no difference in odds of overall complications, infections, reoperations, intracranial hemorrhage, extra-axial fluid collections, seizures, or bone resorption. Subgroup analysis of trauma patients revealed a decreased odds of extra-axial fluid collection (OR 0.30, p=0.02) and an increased odds of hydrocephalus (OR 4.99, p=0.05). Early cranioplasty within 90days after decompressive craniectomy is associated with an increased odds of hydrocephalus than with later cranioplasty, but no difference in odds of developing other complications. Earlier cranioplasty in the trauma population is associated with fewer extra-axial fluid collections.