Journal of Neurosurgery: Pediatrics
Michael M. McDowell, Jason E. Blatt, Christopher P. Deibert, Nathan T. Zwagerman, Zachary J. Tempel and Stephanie Greene
Chiari malformation type II (CM-II) in myelomeningocele is associated with a significant rate of mortality and poor outcome. Death is frequently heralded by the onset or progression of neurological symptoms. The authors sought to identify predictors of poor outcome and mortality within the myelomeningocele population at Children’s Hospital of Pittsburgh.
A retrospective chart and radiology review was performed on all infants who underwent primary closure of a myelomeningocele defect at Children’s Hospital of Pittsburgh between the years of 1995 and 2015. Preoperative symptoms and signs leading to CM-II decompression, as well as operative details and postoperative changes in these symptoms and signs, were investigated in detail and correlated to outcome. Poor outcome was defined as death, stridor, or ventilator dependence. Deceased patients were separately assessed within this subgroup.
Thirty-two (21%) of 153 patients were found to have symptomatic CM-II. Of the 32 patients meeting inclusion criteria, 12 (38%) had poor outcomes. Eight patients (25%) died since initial presentation; 5 of these patients (16% of the overall cohort) died within the 1st year of life and 3 (9%) died during adolescence. Seven (88%) of the 8 patients who died had central apnea on presentation (p = 0.001) and 7 (44%) of the 16 patients who developed symptoms in the first 3 months of life died, compared with 1 (6.3%) of 16 who developed symptoms later in childhood (p = 0.04). The median Apgar score at 1 minute was 4.5 for patients who died and 8 for surviving patients (p = 0.006). The median diameter of the myelomeningocele defect was 5.75 cm for patients who died and 5 for those who survived (p = 0.01). The anatomical level of defect trended toward higher levels in patients who died, with 4 patients in that group having an anatomical level at L-2 or higher compared with 5 of the surviving patients (p = 0.001). The median initial head circumference for the 5 patients dying in the 1st year of life was 41.5 cm, versus 34 cm for all other patients (p = 0.01).
CM-II in spina bifida is associated with a significant mortality rate even when surgical intervention is performed. Death is more frequent in symptomatic patients presenting prior to 1 year of age. Late deaths are associated with symptom progression despite aggressive surgical and medical intervention. In this patient cohort, death was more likely in patients with symptomatic presentation during the first 3 months of life, low Apgar scores, large myelomeningocele defects, early central apnea, and large head circumference at birth.
Brandon G. Rocque, Bonita S. Agee, Eric M. Thompson, Mark Piedra, Lissa C. Baird, Nathan R. Selden, Stephanie Greene, Christopher P. Deibert, Todd C. Hankinson, Sean M. Lew, Bermans J. Iskandar, Taryn M. Bragg, David Frim, Gerald Grant, Nalin Gupta, Kurtis I. Auguste, Dimitrios C. Nikas, Michael Vassilyadi, Carrie R. Muh, Nicholas M. Wetjen and Sandi K. Lam
In children, the repair of skull defects arising from decompressive craniectomy presents a unique set of challenges. Single-center studies have identified different risk factors for the common complications of cranioplasty resorption and infection. The goal of the present study was to determine the risk factors for bone resorption and infection after pediatric cranioplasty.
The authors conducted a multicenter retrospective case study that included all patients who underwent cranioplasty to correct a skull defect arising from a decompressive craniectomy at 13 centers between 2000 and 2011 and were less than 19 years old at the time of cranioplasty. Prior systematic review of the literature along with expert opinion guided the selection of variables to be collected. These included: indication for craniectomy; history of abusive head trauma; method of bone storage; method of bone fixation; use of drains; size of bone graft; presence of other implants, including ventriculoperitoneal (VP) shunt; presence of fluid collections; age at craniectomy; and time between craniectomy and cranioplasty.
A total of 359 patients met the inclusion criteria. The patients’ mean age was 8.4 years, and 51.5% were female. Thirty-eight cases (10.5%) were complicated by infection. In multivariate analysis, presence of a cranial implant (primarily VP shunt) (OR 2.41, 95% CI 1.17–4.98), presence of gastrostomy (OR 2.44, 95% CI 1.03–5.79), and ventilator dependence (OR 8.45, 95% CI 1.10–65.08) were significant risk factors for cranioplasty infection. No other variable was associated with infection.
Of the 240 patients who underwent a cranioplasty with bone graft, 21.7% showed bone resorption significant enough to warrant repeat surgical intervention. The most important predictor of cranioplasty bone resorption was age at the time of cranioplasty. For every month of increased age the risk of bone flap resorption decreased by 1% (OR 0.99, 95% CI 0.98–0.99, p < 0.001). Other risk factors for resorption in multivariate models were the use of external ventricular drains and lumbar shunts.
This is the largest study of pediatric cranioplasty outcomes performed to date. Analysis included variables found to be significant in previous retrospective reports. Presence of a cranial implant such as VP shunt is the most significant risk factor for cranioplasty infection, whereas younger age at cranioplasty is the dominant risk factor for bone resorption.