Gregory G Heuer

The Children's Hospital of Philadelphia | CHOP · Department of Neurosurgery

Objective To (1) describe differences in types and timing of interventions, (2) report short-term outcomes and (3) describe differences among centres from a large national cohort of preterm infants with post-haemorrhagic hydrocephalus (PHH). Design Cohort study of the Children’s Hospitals Neonatal Database from 2010 to 2022. Setting 41 referral n...

Purpose Historically, the presence of gray matter heterotopia was a concern for adverse postnatal neurocognitive status in patients undergoing fetal closure of open spinal dysraphism. The purpose of this study was to evaluate neurodevelopmental outcomes and the onset of seizures during early childhood in patients with a prenatal diagnosis of myelom...

OBJECTIVE Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) follo...

INTRODUCTION Gray matter heterotopia is a cortical malformation and a known risk factor for seizures and epilepsy. Historically, presence of heterotopia in one or both cerebral ventricles was a concern for postnatal neurological status in patients undergoing fetal closure of myelomeningocele/myeloschisis. There is little information known regarding...

INTRODUCTION Prenatal repair is the gold standard for appropriate patients with fetal myelomeningocele/myeloschisis. Hindbrain herniation is a prerequisite for fetal repair; however, there is a subset of patients without herniation on initial imaging and then progress to herniation on subsequent prenatal/postnatal imaging. METHODS From July 2016 t...

Purpose: Treatment of subjects with refractory idiopathic intracranial hypertension (IIH) or shunted hydrocephalus with chronic shunt complications is challenging. What is the role for cranial vault expansion, particularly utilizing posterior vault distraction osteogenesis (PVDO), in these cases? This study assesses medium-term efficacy of cranial...

Purpose Historically, the presence of gray matter heterotopia was a concern for adverse postnatal neurocognitive status in patients undergoing fetal closure of open spinal dysraphism. The purpose of this study was to evaluate neurodevelopmental outcomes and the onset of seizures during early childhood in patients with a prenatal diagnosis of myelom...

OBJECTIVE Among patients with a history of prior lipomyelomeningocele repair, an association between increased lumbosacral angle (LSA) and cord retethering has been described. The authors sought to build a predictive algorithm to determine which complex tethered cord patients will develop the symptoms of spinal cord retethering after initial surgic...

OBJECTIVE Abusive head trauma (AHT) is one of the most devastating forms of pediatric traumatic brain injury (TBI). It commonly presents with seizures, which may contribute to poor neurological outcome following trauma. Noninvasive near-infrared spectroscopy (NIRS) neuromonitoring may provide information on cerebral oxygenation and perfusion. In th...

Background Fronto-orbital distraction osteogenesis (FODO) is an established surgical technique for patients with unicoronal craniosynostosis. Our institution has employed an endoscopic-assisted “endo-FODO” in recent years to decrease cutaneous scarring and lessen our impact on the functional growth matrix. This study compares perioperative outcomes...

PurposeThe incidence of metabolic bone diseases in pediatric neurosurgical patients is rare. We examined our institutional experience of metabolic bone diseases along with a review of the literature in an effort to understand management for this rare entity.Methods Retrospective review of the electronic medical record database was performed to iden...

Background: Elevated intracranial pressure (ICP) in sagittal craniosynostosis has a wide spectrum of reported incidence, and patterns are not well understood across infancy and childhood. Characterizing the natural history of ICP in this population may clarify risks for neurocognitive delay and inform treatment decisions. Methods: Infants and ch...

Background Brachial plexus region tumors are rare. In this study, we reviewed our experience with resection of tumors involving or adjacent to the brachial plexus to identify patterns in presentation and outcome. Methods We report a retrospective case series of brachial plexus tumors operated on by a single surgeon at a single institution over 15...

Introduction The development of a spinal pseudomeningocele is a complication of dural repair or reconstruction that carries significant morbidity for pediatric patients. In addition to cerebrospinal fluid (CSF) hypotension and positional headaches, CSF leaking into the extradural space increases the risk for incisional breakdown, meningitis, and co...

Background Fronto-orbital advancement and remodeling (FOAR) is among the most common surgical approaches for unicoronal craniosynostosis (UCS), although some data demonstrate failure to achieve long-term aesthetic normalcy, leading some to seek alternative treatment paradigms such as fronto-orbital distraction osteogenesis (FODO). This study compar...

Hydrocephalus is defined as a distention of the ventricular system of the brain that is the result of inadequate flow of cerebrospinal fluid from the location where it is produced within the ventricles to its site of absorption into systemic circulation. The prevalence of hydrocephalus has increased in the general population due to advances in neur...

Severe traumatic brain injury remains a leading causes of acquired disability and death in children, with the highest combined rates of TBI-related emergency department visits, hospitalizations, and deaths occurring in the youngest age groups. While the most effective strategy is preventing trauma in the first place, a large number of patients stil...

Purpose The purpose of the study was to better understand the clinical course and impact of tethered cord release surgery on patients who have previously undergone open spinal dysraphism closure in utero. Methods This is a single-center retrospective observational study on patients undergoing tethered cord release after having previously had open...

Head and neck positioning is a key element of craniofacial reconstructive surgery and can become challenging when intervention necessitates broad exposure of the calvarium. We present a case of craniosynostosis secondary to Apert's syndrome requiring anterior and posterior cranial vault access during surgical correction. A modified sphinx position...

Purpose: To better understand the clinical course and impact of tethered cord release surgery on patients who have previously undergone open spinal dysraphism closure in utero. Methods: This is a single-center retrospective observational study on patients undergoing tethered cord release after having previously had open fetal myelomeningocele (MMC)...

Background: A larger volume cranial vault expansion is likely facilitated by a low posterior cranial osteotomy beneath the torcula; however, this may impart an increased risk of venous bleeding. This study compares the safety infra-torcular to supra-torcular osteotomy in patients undergoing posterior vault reconstruction (PVR) or posterior vault d...

OBJECTIVE Hydrocephalus is common among children with myelomeningocele and is most frequently treated with a ventriculoperitoneal shunt (VPS). Although much is known about factors related to first shunt failure, relatively less data are available about shunt failures after the first one. The purpose of this study was to use a large data set to expl...

OBJECTIVE Complex tethered spinal cord (cTSC) release in children is often complicated by surgical site infection (SSI). Children undergoing this surgery share many similarities with patients undergoing correction for neuromuscular scoliosis, where high rates of gram-negative and polymicrobial infections have been reported. Similar organisms isolat...

Purpose: Ventriculoperitoneal (VP) shunt placement is a common neurosurgical procedure performed in patients with early onset scoliosis (EOS). To provide insight into the risks of spine lengthening operations, we investigate the rate of VP shunt complications in patients with EOS undergoing spinal deformity correction interventions. Methods: A r...

Objective: Severe traumatic brain injury (TBI) is a leading cause of disability and death in the pediatric population. While intracranial pressure (ICP) monitoring is the gold standard in acute neurocritical care following pediatric severe TBI, brain tissue oxygen tension (PbtO2) monitoring may also help limit secondary brain injury and improve ou...

Anterior cranial vault fronto-orbital distraction osteogenesis is a promising treatment modality for children with unicoronal craniosynostosis. A minimally invasive, endoscope-assisted approach offers the additional potential benefits of less scalp scarring, decreased blood loss, and decreased scalp dissection. In this article, the authors present...

While the focus of craniosynostosis surgery is to improve head shape, neurocognitive sequelae are common and are incompletely understood. Neurodevelopmental problems that children with craniosynostosis face include cognitive and language impairments, motor delays or deficits, learning disabilities, executive dysfunction, and behavioral problems. St...

OBJECTIVE The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM). METHODS The authors used retrospective and prospective components of the Park-Re...

Background: Craniosynostosis may lead to elevated intracranial pressure, which may be implicated with impaired neurocognitive development. However, accurately measuring intracranial pressure is challenging, and patterns in craniosynostosis patients are poorly characterized. Spectral-domain optical coherence tomography may enable noninvasive assess...

Introduction: Ultrasound (US) based indexes such as fronto-occipital ratio (FOR) can be used to obtain an acceptable estimation of ventricular volume. Patients with colpocephaly present a unique challenge due to the shape of their ventricles. In the present study, we aim to evaluate the validity and reproducibility of modified US-FOR index in chil...

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Introduction: Pediatric severe traumatic brain injury (TBI) is one of the leading causes of disability and death. One of the classic pathoanatomic brain injury lesions following severe pediatric TBI is diffuse (multifocal) axonal injury (DAI). In this single institution study, our overarching goal was to describe the clinical characteristics and lo...

OBJECTIVE Children with multiple prematurely fused cranial sutures and those undergoing surgical correction later in life appear to experience worse neurocognitive outcomes, but it is unclear whether higher intracranial pressure (ICP) is implicated in this process. The purpose of this study was to elucidate the effect of age at intervention and num...

Background: The purpose of this manuscript is to introduce a novel endoscopic-assisted approach for creation of osteotomies and distractor hardware placement for unicoronal craniosynostosis. Methods: Only three small incisions are performed, one at the anterior fontanelle, pterional region, and upper lateral blepharoplasty location. Unicoronal s...

Objective: Endoscopic strip craniectomy (ESC) and spring-mediated cranioplasty (SMC) are two minimally invasive techniques for treating sagittal craniosynostosis in early infancy. Data comparing the perioperative outcomes of these two techniques are sparse. Here, the authors hypothesized that outcomes would be similar between patients undergoing S...

Objective This study aimed to determine clinical care practices for infants at risk for posthemorrhagic hydrocephalus (PHH) across level IV neonatal intensive care units (NICUs). Study Design Cross-sectional survey that addressed center-specific surveillance, neurosurgical intervention, and follow-up practices within the Children's Hospitals Neonat...

The purpose of this study was to compare perioperative safety and efficacy of posterior vault distraction osteogenesis (PVDO) in patients with primary nonsynostotic cephalo-cranial disproportion, namely slit ventricle syndrome and idiopathic intracranial hypertension (IIH), to a cohort of patients with craniosynostosis (CS). A retrospective review...

OBJECTIVE Single-ventricle congenital heart disease (CHD) in pediatric patients with Glenn and Fontan physiology represents a unique physiology requiring the surgical diversion of the systemic venous return from the superior vena cava (Glenn) and then the inferior vena cava (Fontan) directly to the pulmonary arteries. Because many of these patients...

OBJECTIVE Scoliosis is common in patients with Chiari malformation type I (CM-I)–associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression. METHODS A large multicenter retrospecti...

Objective To demonstrate that a novel non-invasive index of intracranial pressure (ICP) derived from diffuse optics-based techniques is associated with intracranial hypertension. Study design We compared non-invasive and invasive ICP measurements in infants with hydrocephalus. Infants born term and preterm were eligible for inclusion if clinically...

Cranial spring hardware is generally removed 3 months after placement for spring-mediated cranioplasty. Spring removal is performed as an outpatient procedure under general anesthesia in approximately 15 minutes through the incision locations of the index procedure. Herein, the authors provide a multimedia demonstration of cranial spring hardware r...

Spring-mediated cranioplasty is a useful treatment modality for correcting scaphocephalic head shape in sagittal craniosynostosis because it is less invasive than whole-vault cranioplasty and offers durable morphologic outcomes. Herein, the authors provide a multimedia demonstration of alternative operative approaches for spring-mediated cranioplas...

OBJECTIVE Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and...

Neurogenic thoracic outlet syndrome (nTOS) describes a set of disorders related to symptomatic compression of the brachial plexus as it passes through the thoracic outlet into the arm. In children, nTOS is a rare and frequently delayed diagnosis due to the difficulty of communicating symptoms with adults and healthcare providers and decreased preva...

BACKGROUND Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology. OBJECTIVE To examine factors influencing the use of OCF and OCF/VD in a multicent...

Background: Open maternal-fetal surgery for in utero closure of myelomeningocele (MMC) has become an accepted treatment option for prenatally diagnosed open neural tube defects. Historically, this option has been limited to women with BMI < 35 due to concern for increasing complications in patients with obesity. Objective: The aim of this study...

BACKGROUND AND PURPOSE: Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnat...

Background Preterm infants with post-hemorrhagic hydrocephalus (PHH) are often treated with temporizing measures such as ventricular access devices (VADs) in order to drain cerebrospinal fluid (CSF) prior to permanent diversion with ventriculoperitoneal shunt (VPS) placement. Local problem There is little consensus on the timing and management of...

Background Optic pathway gliomas (OPGs) are low-grade tumors of the white matter of the visual system with a highly variable clinical course. The aim of the study was to generate a MRI-based predictive model of OPG tumor progression using advanced image analysis and machine learning techniques. Methods We performed a retrospective case-control stu...

OBJECTIVE Head of bed (HOB) elevation to 30° after severe traumatic brain injury (TBI) has become standard positioning across all age groups. This maneuver is thought to minimize the risk of elevated ICP in the hopes of decreasing cerebral blood and fluid volume and increasing cerebral venous outflow with improvement in jugular venous drainage. How...

Background: Thermal flow evaluation (TFE) is a non-invasive method to assess ventriculoperitoneal shunt function. Flow detected by TFE is a negative predictor of the need for revision surgery. Further optimization of testing protocols, evaluation in multiple centers, and integration with clinical and imaging impressions prompted the current study....

Objective: Factors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established. Methods: Using the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variable...

Background Better understanding the incidence and patterns of elevated intracranial pressure (ICP) in patients with craniosynostosis may facilitate more timely intervention to alter neurocognitive outcomes. Spectral-domain optical coherence tomography (OCT) of the retina can non-invasively diagnose elevated ICP, and has demonstrated high sensitivit...

Study design: This is a level IV retrospective descriptive study at a single institution. Objective: The objective of the study was to determine the preoperative signs or symptoms prompting cervicomedullary imaging in Jeune syndrome. Summary of background data: Jeune syndrome is a rare autosomal recessive disorder that results in pulmonary com...

Thoracic myelocystocele are extremely rare, non-terminal, closed neural tube defects. Intraoperative neuromonitoring (IONM) is a mainstay of pediatric spinal surgery. However, in neonates and infants, incomplete myelination of the corticospinal tract presents unique challenges to successful use of IONM in this vulnerable patient population. Surgery...

Objective: The lack of a continuous, noninvasive modality for monitoring intracranial pressure (ICP) is a major obstacle in the care of pediatric patients with hydrocephalus who are at risk for intracranial hypertension. Intracranial hypertension can lead to cerebral ischemia and brain tissue hypoxia. In this study, the authors evaluated the use o...

Purpose Children with myelomeningocele (MMC) are at increased risk of developing neuromuscular scoliosis and spinal cord re-tethering (Childs Nerv Syst 12:748-754, 1996; Neurosurg Focus 16:2, 2004; Neurosurg Focus 29:1, 2010). Some centers perform prophylactic untethering on asymptomatic MMC patients prior to scoliosis surgery because of concern th...

Background: Placement of ventriculoperitoneal shunts (VPS) can be challenging in children with previous VPS, previous abdominal surgery, or complex abdominal pathology. Laparoscopy can help identify intra-abdominal adhesions and determine the optimal site for insertion of the distal VPS catheter. We analyzed the feasibility and safety of laparosco...

This paper describes some of the more common patterns in neurobehavioral deficits and their underlying neuroanatomical basis in myelomeningocele (MMC). Patients with MMC can face a lifetime of specific organ system dysfunction, chief among them spinal cord malformations, orthopedic issues, hydrocephalus, and urological disabilities. In addition, pa...

Objective: The Management of Myelomeningocele Study (MOMS) compared prenatal with postnatal surgery for myelomeningocele (MMC). The present study sought to determine how MOMS influenced the clinical recommendations of pediatric neurosurgeons, how surgeons' risk tolerance affected their views, how their views compare to those of their colleagues in...

Myelomeningocele (MMC) affects approximately 2000 infants in the US yearly and causes long-term damage to the genitourinary system. There is a wide spectrum of effects on the bladder and urethral sphincter that do not correlate with the level of the spinal cord defect. The bladder changes can provide a safe storage pressure, often at the expense of...

Objectives: To determine whether the presence of a myelomeningocele sac and myelomeningocele sac size correlate with compromised lower extremity function. Methods: A single center, retrospective radiology database search was performed for cases of myelomeningocele (MMC) and myeloschisis (MS) prenatally diagnosed from 2013-2017. Ultrasound report...

Background: The Management of Myelomeningocele Study (MOMS) demonstrated that fetal myelomeningocele (fMMC) closure results in improved hydrocephalus and hindbrain herniation when compared to postnatal closure. Objective: To report on the outcomes of a single institution's experience in the post-MOMS era, with regard to hydrocephalus absence and...

Objective: Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors' goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis. Methods: A large multicenter retrospective and prospective registry...

Objective: External ventricular drains (EVDs) are commonly used in the neurosurgical population. However, very few pediatric neurosurgery studies are available regarding EVD-associated infection rates with antibiotic-impregnated EVD catheters. The authors previously published a large pediatric cohort study analyzing nonantibiotic-impregnated EVD c...

Background: The effect of modifications in fetal myelomeningocele (fMMC) closure techniques has not been extensively studied. Objective: To study the effect of a modified closure technique on fMMC postnatal patient outcomes: hydrocephalus, hindbrain herniation, and cyst development. Methods: We performed single-center retrospective study of a...

OBJECTIVE Although it is known that intersurgeon variability in offering elective surgery can have major consequences for patient morbidity and healthcare spending, data addressing variability within neurosurgery are scarce. The authors performed a prospective peer review study of randomly selected neurosurgery cases in order to assess the extent o...

Conjoined twins who are classified as craniopagus (joined at the cranium) have a rare congenital anomaly. Despite advances in surgical techniques and critical care, the rate of complications and death is still high among twins with total fusion in which the superior sagittal sinus is shared. Here, we describe total-fusion craniopagus twins who at 1...

OBJECTIVE Complications after complex tethered spinal cord (cTSC) surgery include infections and cerebrospinal fluid (CSF) leaks. With little empirical evidence to guide management, there is variability in the interventions undertaken to limit complications. Expert-based best practices may improve the care of patients undergoing cTSC surgery. Here,...

INTRODUCTION Congenital hydrocephalus (CH) is a major cause of childhood morbidity and mortality, affecting 1 in 1000 live births and representing up to 3% of all pediatric hospital charges in the USA. Accordingly, CH is a major financial burden on health care systems worldwide, and costs the US health care system alone greater than $2 billion annu...

OBJECTIVE Evaluation of increased intracranial pressure (ICP) in the pediatric craniosynostosis population based solely on ophthalmological, clinical, and radiographic data is subjective, insensitive, and inconsistent. The aim of this study was to examine the intraoperative ICP before and after craniectomy in this patient population. METHODS The a...

Objective: Post-ictal EEG alterations have been identified in studies of intracranial recordings, but the clinical significance of post-ictal EEG activity is undetermined. The purpose of this study was to examine the relationship between peri-ictal EEG activity, surgical outcome, and extent of seizure propagation in a sample of pediatric epilepsy...

Importance Which children with fetal ventriculomegaly, or enlargement of the cerebral ventricles in utero, will develop hydrocephalus requiring treatment after birth is unclear. Objective To determine whether extraction of multiple imaging features from fetal magnetic resonance imaging (MRI) and integration using machine learning techniques can pr...

Endoscopic third ventriculostomy (ETV) has become a popular technique for the treatment of hydrocephalus, but small sample size has limited the generalizability of prior studies. We performed a large-scale review of all available studies to help eliminate bias and determine how outcomes have changed and been influenced by patient selection over tim...

OBJECTIVE Neurogenic thoracic outlet syndrome (nTOS) is an uncommon compression syndrome of the brachial plexus that presents with pain, sensory changes, and motor weakness in the affected limb. The authors reviewed the clinical presentations and outcomes in their series of pediatric patients with surgically treated nTOS over a 6-year period. METH...

Intraoperative neuromonitoring (IONM) has transformed the fields of pediatric surgery and anesthesia since its introduction in 1979, and is an important diagnostic and preventative tool to potentially decrease neurological complications in children after surgical procedures. Its value in minimizing neurological injury during surgery has been well e...

Severe pediatric traumatic brain injury (TBI) remains one of the leading causes of acquired disability and death in the USA, with the highest combined rates of TBI-related emergency room visits, hospitalizations, and deaths occurring in the youngest age. While the most effective treatment is preventing trauma in the first place, a large number of p...

Fetal ventriculomegaly (VM) refers to the enlargement of the cerebral ventricles in utero. It is associated with the postnatal diagnosis of hydrocephalus. VM is clinically diagnosed on ultrasound and is defined as an atrial diameter greater than 10 mm. Because of the anatomic detailed seen with advanced imaging, VM is often further characterized by...

Open spina bifida or myelomeningocele (MMC) is one of the most common serious congenital malformations. Historically, this condition has been treated with closure of the MMC defect shortly after birth. The goal of postnatal closure is to cover the exposed spinal cord and prevent infection. However, postnatal surgery does not reverse or prevent the...

Importance: Detecting elevated intracranial pressure in children with subacute conditions, such as craniosynostosis or tumor, may enable timely intervention and prevent neurocognitive impairment, but conventional techniques are invasive and often equivocal. Elevated intracranial pressure leads to structural changes in the peripapillary retina. Spe...

IntroductionChiari malformation type-1 (CM-1) may be treated by intradural (ID) or extradural (ED) posterior fossa decompression, although the optimal approach is debated. The Chiari Severity Index (CSI) is a pre-operative metric to predict patient-defined improvement after CM-1 surgery. In this study, we evaluate the results of ID versus ED decomp...

Background: Dislocation of the ulnar nerve (UN) occurs in a subset of patients with ulnar neuropathy. Electrodiagnostic and magnetic resonance imaging (MRI) studies are performed to support the clinical diagnosis. We report the case of a patient with ulnar neuropathy with normal electrodiagnostic and MRI studies but with ultrasound (US) showing UN...

OBJECTIVE Fetal ventriculomegaly (FV), or enlarged cerebral ventricles in utero, is defined in fetal studies as an atrial diameter (AD) greater than 10 mm. In postnatal studies, the frontooccipital horn ratio (FOHR) is commonly used as a proxy for ventricle size (VS); however, its role in FV has not been assessed. Using image analysis techniques to...