Endoscopic third ventriculostomy with choroid plexus cauterization: predictors of long-term success and comparison with shunt placement for primary treatment of infant hydrocephalus

OBJECTIVE

Endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) can avoid ventriculoperitoneal shunt (VPS) dependence in very young hydrocephalic children, although long-term success as a primary treatment in North America has not been previously reported. Moreover, optimal age at surgery, impact of preoperative ventriculomegaly, and relationship to prior cerebrospinal fluid (CSF) diversion remain poorly defined. The authors compared ETV/CPC and VPS placement for averting reoperation, and they evaluated preoperative predictors for reoperation and shunt placement after ETV/CPC.

METHODS

All patients under 12 months of age who underwent initial hydrocephalus treatment via ETV/CPC or VPS placement at Boston Children's Hospital between December 2008 and August 2021 were reviewed. Analyses included Cox regression for independent outcome predictors, and both Kaplan-Meier and log-rank rank tests for time-to-event outcomes. Cutoff values for age and preoperative frontal and occipital horn ratio (FOHR) were determined with receiver operating characteristic curve analysis and Youden's J index.

RESULTS

In total, 348 children (150 females) were included with principal etiologies of posthemorrhagic hydrocephalus (26.7%), myelomeningocele (20.1%), and aqueduct stenosis (17.0%). Of these, 266 (76.4%) underwent ETV/CPC and 82 (23.6%) underwent VPS placement. Treatment choice largely reflected surgeon preferences before practice shifted toward endoscopy, with endoscopy not considered for > 70% of initial VPS cases. ETV/CPC patients trended toward fewer reoperations, and Kaplan-Meier analysis estimated that 59% of patients would achieve long-term shunt freedom through 11 years (median 42 months of actual follow-up). Among all patients, corrected age < 2.5 months (p < 0.001), prior temporizing CSF diversion (p = 0.003), and excess intraoperative bleeding (p < 0.001) independently predicted reoperation. Among ETV/CPC patients, corrected age < 2.5 months (p = 0.031), prior CSF diversion (p = 0.001), preoperative FOHR > 0.613 (p = 0.011), and excessive intraoperative bleeding (p = 0.001) independently predicted ultimate conversion to VPS. The actual VPS insertion rates remained low in patients who were ≥ 2.5 months old at ETV/CPC either with prior CSF diversion (2/10 [20.0%]) or without prior CSF diversion (24/123 [19.5%]); however, the actual VPS insertion rates increased in patients who were < 2.5 months old at ETV/CPC with prior CSF diversion (19/26 [73.1%]) or without prior CSF diversion (44/107 [41.1%]).

CONCLUSIONS

ETV/CPC successfully treated hydrocephalus in most patients younger than 1 year irrespective of etiology, averting observed shunt dependence in 80% of patients ≥ 2.5 months of age regardless of prior CSF diversion and in 59% of those < 2.5 months of age without prior CSF diversion. For infants aged < 2.5 months with prior CSF diversion, particularly those with severe ventriculomegaly, ETV/CPC was unlikely to succeed unless safely delayed.

Predictors of progression in radiation-induced versus nonradiation-induced pediatric meningiomas: a large single-institution surgical experience

OBJECTIVE

The goal in this study was to outline unique differences between radiation-induced and nonradiation-induced pediatric meningiomas and to identify independent risk factors of tumor recurrence/progression.

METHODS

This is a retrospective cohort study of all pediatric meningiomas diagnosed and surgically treated at the authors' institution between 1993 and 2017. Multivariable Cox regression was applied to identify independent risk factors for tumor recurrence/progression.

RESULTS

Thirty-five patients were identified. The primary etiology was nonradiation-induced (n = 24: n = 3 with neurofibromatosis type 2) or radiation-induced (n = 11: acute lymphoblastic leukemia [n = 5], medulloblastoma [n = 4], germ cell tumor [n = 1], and primitive neuroectodermal tumor [n = 1]) meningioma. The mean age at time of diagnosis was 10.7 ± 5.7 years for nonradiation-induced and 17.3 ± 3.5 years for radiation-induced meningiomas. Overall, 8/24 patients with nonradiation-induced meningioma experienced either recurrence or progression of the tumor. Of the 8 patients with tumor recurrence or progression, the pathological diagnosis was clear cell meningioma (n = 3: 2 recurrent and 1 progressive); grade I (n = 2 progressive); grade I with atypical features (n = 2: 1 recurrent and 1 progressive); or atypical meningioma (n = 1 recurrent). None of the patients with radiation-induced meningioma experienced recurrence or progression. Predictors of tumor recurrence/progression by univariate analysis included age at time of diagnosis ≤ 10 years (p = 0.002), histological subtype clear cell meningioma (p = 0.003), and primary etiology nonradiation-induced meningioma (p = 0.04), and there was a notable trend with elevated MIB-1 staining index (SI) (p = 0.09). There was no significant difference between nonradiation-induced and radiation-induced meningiomas (p = 0.258), although there was a trend between recurrent and nonrecurrent meningiomas (p = 0.09). Multivariate Cox regression, adjusted for length of follow-up, identified younger age at diagnosis (p = 0.004) and a higher MIB-1 SI (p = 0.044) as independent risk factors for recurrence. Elevated MIB-1 SI statistically correlated with atypia (p < 0.001). However, there was no significant statistical correlation between tumor recurrence/progression and atypia (p = 0.2).

CONCLUSIONS

Younger patient age and higher MIB-1 SI are independent risk factors for recurrence. Atypia was not a predictor of recurrence.

Postoperative MR imaging surveillance of pediatric craniopharyngioma: new institutional guidelines

PURPOSE

To develop postoperative surveillance protocols that yield efficient detection rates of tumor recurrence or progression using fewer imaging studies and less cost.

METHOD

This is a retrospective cohort study of all pediatric craniopharyngioma patients who have been diagnosed and treated at Boston Children's Hospital (BCH) between 1990 and 2017. All statistical analyses were performed using Stata.

RESULTS

Eighty patients (43 males and 37 females) fulfilled the inclusion criteria. The mean age at time of diagnosis was 8.6 ± 4.4 years. The mean follow-up period was 10.9 ± 6.5 years. Overall 30/80 (37.5%) patients experienced tumor recurrence/progression. The median latency to recurrence/progression was 12.75 months (range 3 to 108 months), with 76.6% of the recurrences/progressions taking place within the first 2 years postoperatively. Given the lack of any clinical symptoms/signs associated with the vast majority of the recurrent/progressed cases, we propose postoperative MR imaging surveillance protocols that are substantially less intensive than the current practice. Therefore, we recommend the following postoperative MR imaging surveillance protocols, stratified by management strategies; 0, 9, 15, 36, 48, and 60 months for patients who underwent GTR, 0, 3, 6,12, 18, and 24 months for patients who underwent STR alone and 0, 3, 12, 72, 96, and 120 months for patients who underwent STR followed by subsequent XRT.

CONCLUSION

The proposed postoperative MR imaging surveillance protocols would provide a potential 50% decrement of healthcare costs. It may also minify the psychological burden of frequent MR scanning for these patients and their families.

Surgical volume of simple tethered spinal cord releases: review of a large pediatric neurosurgical service experience

OBJECTIVE

The aim of this study was to retrospectively review, from a single busy pediatric neurosurgical service, a consecutive series of patients who had undergone surgery for a simple tethered spinal cord, which was defined by a thickened or fatty filum terminale with a normal conus. The hope was to contribute to benchmark data regarding the expected frequency of surgery for this condition.

METHODS

The authors reviewed the electronic medical records of every patient with diagnosed simple tethered spinal cord, defined on spinal MRI as a thickened (> 2 mm in diameter) or fatty filum terminale, and who had undergone primary filum section at Boston Children's Hospital between 2005 and 2011.

RESULTS

A total of 208 patients met the study inclusion criteria. At the time of surgery, patients ranged in age from 0.4 to 19.8 years. One hundred forty-four (69%) patients were symptomatic with one or more of the following: bowel/bladder dysfunction, 94 (45%); neurological dysfunction, 49 (24%); scoliosis, 44 (21%); or back pain, 44 (21%). Sixty-four (31%) patients were asymptomatic and were operated on prophylactically when filum pathology was discovered during the course of a workup for clinical syndromes such as anorectal anomalies and/or suspicious cutaneous lesions. No patients in this series were operated on if they had normal MRI studies, defined as a conus tip no lower than L3 and no distal tethering lesion visualized. Over the study period, approximately 1000 major surgical cases were performed in the department every year, only 30 of which were simple detethering procedures, representing well under 5% of the service's operative volume and approximately 5 cases per surgeon per year. Clinical follow-up, available at a postoperative interval of 6.6 ± 3.8 years, demonstrated that approximately 80% of patients symptomatic with bowel or bladder involvement or neurological dysfunction had improvement or relief of their symptoms and that none of the patients treated prophylactically experienced new-onset symptoms that could be related to spinal tethering.

CONCLUSIONS

Simple detethering procedures were relatively uncommon in an active, well-established pediatric neurosurgical service and represented less than 5% of the service's total case volume per year with an average of 5 cases per surgeon per year. No patients with normal MRI studies were operated on during the study period.

The utility of intraoperative MRI during pediatric brain tumor surgery: a single-surgeon case series

OBJECTIVE

The authors sought to evaluate the utility of intraoperative MRI (ioMRI) during brain tumor excision in pediatric patients and to suggest guidelines for its future use.

METHODS

All patients who underwent brain tumor surgery by the senior author at Boston Children's Hospital using ioMRI between 2005 and 2009 were included in this retrospective review of hospital records and the neurosurgeon's operative database. Prior to the review, the authors defined the utility of ioMRI into useful and not useful categories based on how the technology affected operative management. They determined that ioMRI was useful if it 1) effectively guided the extent of resection; 2) provided a baseline postoperative scan during the same anesthesia session; or 3) demonstrated or helped to prevent an intraoperative complication. The authors determined that ioMRI was not useful if 1) the anatomical location of the tumor had precluded a tumor's total resection, even though the surgeon had employed ioMRI for that purpose; 2) the tumor's imaging characteristics prevented an accurate assessment of resection during intraoperative imaging; 3) the surgeon deemed the technology not required for tumor resection; or 4) the intraoperative MR images were uninterpretable for technical reasons. Follow-up data provided another gauge of the long-term benefit of ioMRI to the patient.

RESULTS

A total of 53 brain tumor patients were operated on using ioMRI, 6 of whom had a second ioMRI procedure during the study period. Twenty-six patients were female, and 27 were male. The mean follow-up was 4.8 ± 3.85 years (range 0-12 years). By the criteria outlined above, ioMRI technology was useful in 38 (64.4%) of the 59 cases, most frequently for its help in assessing extent of resection.

CONCLUSIONS

Intraoperative MRI technology was useful in the majority of brain tumor resections in this series, especially in those tumors that were contrast enhancing and located largely within accessible areas of the brain. The percentage of patients for whom ioMRI is useful could be increased by preoperatively evaluating the tumor's imaging characteristics to determine if ioMRI would accurately assess the extent of tumor resection, and by the surgeon's preoperative understanding that use of the ioMRI will not lead to resection of an anatomically unresectable tumor. The ioMRI can prove useful in unresectable tumors if specific operative goals are defined preoperatively.