Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure.

Cross-Sectional Analysis on Racial and Economic Disparities Affecting Mortality in Preterm Infants with Posthemorrhagic Hydrocephalus.

BACKGROUND: Despite major advances in medicine, racial and socioeconomic disparities continue to affect health care outcomes. Higher overall infant mortality has been reported for black neonates compared with their Hispanic and white counterparts. The underlying basis for these differences remains unclear. A potential influencing factor is the management of premature neurologic complications in this disadvantaged group. This study examines racial and socioeconomic disparities on mortality in preterm infants with posthemorrhagic hydrocephalus (PHH). METHODS: Data from the Nationwide Inpatient Sample and Kids Inpatient Database were combined from 2000 to 2010. Discharges with International Classification of Diseases, Ninth Revision, Clinical Modification codes for preterm births with intraventricular hemorrhage and PHH were included. Relative risk (RR) ratios for mortality, complications, length of stay, and hospital costs were obtained with multivariate analysis after controlling for patient-level, hospital-level, and admission-level factors. RESULTS: When controlling for patient and hospital factors, black neonates had increased mortality compared with whites and Hispanics (RR = 1.47; P < 0.01). This association existed despite lower rates of congenital cardiac defects (RR = 0.84; P < 0.01), gastrointestinal complications (RR = 0.84; P < 0.01), and general complications of prematurity (RR = 0.95; P = 0.04) in the black cohort. Preterm infants insured by Medicaid had increased mortality compared with those with private insurance (RR = 1.2; P = 0.04) after adjusting for patient and hospital factors. CONCLUSIONS: Among preterm infants with intraventricular hemorrhage and resultant PHH, black infants and those insured by Medicaid have significantly increased mortality but these 2 effects are independent. Further studies are needed to fully understand the factors affecting these racial and socioeconomic disparities.

Racial and socioeconomic disparities in outcomes following pediatric cerebrospinal fluid shunt procedures.

OBJECT Racial and socioeconomic disparities within the US health care system are a growing concern. Despite extensive research and efforts to narrow such disparities, minorities and economically disadvantaged patients continue to exhibit inferior health care outcomes. Disparities in the delivery of pediatric neurosurgical care are understudied. Authors of this study examine the impact of race and socioeconomic status on outcomes following pediatric CSF shunting procedures. METHODS Discharge information from the 2000, 2003, 2006, and 2009 Kids' Inpatient Database for individuals (age < 21 years) with a diagnosis of hydrocephalus who had undergone CSF shunting procedures was abstracted for analysis. Multivariate logistic regression analyses, adjusting for patient and hospital factors and annual CSF shunt procedure volume, were performed to evaluate the effects of race and payer status on the likelihood of inpatient mortality and nonroutine hospital discharge (that is, not to home). RESULTS African American patients (p < 0.05) had an increased likelihood of inpatient death and nonroutine discharge compared with white patients. Furthermore, Medicaid patients had a significantly higher likelihood of nonroutine discharge (p < 0.05) as compared with privately insured patients. CONCLUSIONS Findings in this study, which utilized US population-level data, suggest the presence of racial and socioeconomic status outcome disparities following pediatric CSF shunting procedures. Further studies on health disparities in this population are warranted.

Assessment of long-term remission of acromegaly following surgery.

OBJECT: The criteria for remission of acromegaly following transsphenoidal adenoma resection are in evolution. In the present study the authors evaluate the utility of predicting long-term remission by reference to a single fasting growth hormone (GH) level on the 1st postoperative day. METHODS: A retrospective analysis was conducted on 181 patients with acromegaly who underwent transsphenoidal resection between 1973 and 1990 and completed a 5-year follow-up period. Fasting serum GH levels were obtained in all patients on the 1st postoperative day in the absence of exogenous glucocorticoids. All patients participated in a follow-up evaluation lasting at least 5 years, which included measurements of serum insulin-like growth factor-I (IGF-I) levels as an index of acromegalic activity. Among the 181 patients, GH levels ranged from 0 to 8 ng/ml in 131 (72%) on the 1st postoperative day, suggesting biochemical remission. This group included 107 (84%) of the 127 patients with microadenomas, but only 24 (44%) of the 54 with macroadenomas. Nevertheless, 15 (11%) of the 131 patients who initially had attenuated GH levels displayed recurrent acromegaly within the first 2 years (with elevated levels of IGF-I in all cases, and abnormalities appearing on magnetic resonance images in nine cases). Only one of 116 patients in whom the initial postoperative GH level was lower than 2 ng/ml experienced a recurrence, whereas 14 (93%) of the 15 patients with postoperative GH levels between 2.2 and 8 ng/ml subsequently displayed biochemical evidence of acromegaly. CONCLUSIONS: The findings indicate that a fasting morning serum GH level lower than 2 ng/ml on the 1st postoperative day portends long-term biochemical remission of acromegaly, whereas higher levels are a significant marker for recurrent disease.