Akash Patel - Academia.edu (original) (raw)

Papers by Akash Patel

Journal of Neurosurgery, 2009

Metastatic sarcoma to the brain is rare and represents a therapeutic challenge due to its relativ... more Metastatic sarcoma to the brain is rare and represents a therapeutic challenge due to its relative resistance to radio- and chemotherapy. Resection has traditionally been the mainstay of treatment. The authors reviewed a series of patients with metastatic sarcoma to the brain treated surgically to determine outcomes and identify predictors of survival in these patients. A retrospective review of prospectively collected data was undertaken on patients undergoing surgery between 1993 and 2005 for metastatic sarcoma to the brain at The University of Texas, M.D. Anderson Cancer Center. During the study period, 62 patients underwent 84 operations for metastatic sarcoma to the brain. The median postoperative overall and progression-free survival rates were 7.5 and 4.7 months, respectively. Fifty-nine (95%) of 62 patients had a gross-total resection. The 30-day mortality rate was 4.2%. The Karnofsky Performance Scale scores at discharge from the hospital and 3 months postoperatively were the same or improved in 50 (85%) of 59 and 26 (51%) of 51, respectively. Overall postcraniotomy survival was 62% at 6 months, 39% at 1 year, 21% at 2 years, and 8% at 5 years. In multivariate and univariate analysis, control of systemic disease, and sarcomas originating from bone, cartilage, or soft tissue were predictors of survival. Patients with control of systemic disease had survival advantage when compared with those who did not. In patients with alveolar soft-part sarcoma, there was a significantly increased survival advantage compared with all other histological subgroups. The authors' results suggest that in selected patients, resection of metastatic sarcoma to the brain is associated with a relatively low risk of operative death and results in improvement in neurological function. Patients with systemic control of their primary disease and certain histological subtypes (specifically alveolar soft-part sarcoma) have improved overall and progression-free survival.

The American Journal of Cardiology, 2014

Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arter... more Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arterial hypertension (PAH). We examined the electrocardiographic findings that are common in pediatric PAH and assessed for correlation with disease severity and progression. We retrospectively identified patients aged≤18 years followed at a single institution from January 2001 to June 2012 with catheterization-confirmed diagnosis of idiopathic PAH and PAH secondary to pulmonary developmental abnormalities. Patients with an electrocardiography performed within 60 days of catheterization were included. Primary and secondary outcomes are the prevalence of abnormal electrocardiographic findings at the time of catheterization and the association between electrocardiographic and hemodynamic findings and electrocardiographic changes with disease progression on follow-up catheterization, respectively. Of the 100 electrocardiography-catheterization pairs derived from the 46 patients identified, 93% had an electrocardiographic abnormality: 78% had right ventricular hypertrophy (RVH) and 52% had right axis deviation (RAD) for age. In patients with idiopathic PAH, the presence of RVH and RAD correlated with pulmonary vascular resistance and transpulmonary gradient. RAD and RVH on baseline electrocardiogram was associated with an increased risk of disease progression on subsequent catheterization (odds ratio 11.0, 95% confidence interval 1.3 to 96.2, p=0.03) after adjusting for PAH subgroup. The sensitivity, specificity, and positive and negative predictive values of RAD and RVH on baseline electrocardiogram for disease progression were 92%, 48%, 33%, and 95%, respectively. In conclusion, electrocardiographic abnormalities are common in pediatric PAH. RAD and RVH on electrocardiogram were associated with worse hemodynamics, whereas their absence is suggestive of a lack of disease progression.

Moller/Pediatric Cardiovascular Medicine, 2012

ABSTRACT Heart failure in children is an increasingly recognized clinical entity. Etiologies are ... more ABSTRACT Heart failure in children is an increasingly recognized clinical entity. Etiologies are diverse and treatment options are expanding. Although the evidence base for the treatment of heart failure in adults is well developed, much less is known about the efficacy of available treatments in children with heart failure. This chapter focuses on the mechanisms, etiologies, treatment options, and outcomes in children with heart failure secondary to systemic ventricular dysfunction.

Journal of Clinical Anesthesia, 2014

To perform a qualitative analysis of noncardiac patients who developed suspected intraoperative s... more To perform a qualitative analysis of noncardiac patients who developed suspected intraoperative supraventricular tachycardia (SVT) during general anesthesia. Retrospective database analysis and chart review. Operating room of a university-affiliated children's hospital. The records of children without cardiac disease who received general anesthesia at The Children's Hospital of Philadelphia from July 1998 through June 2011 were reviewed. Patients with heart rate values above 180 beats per minute were identified, as were specific medications or key words in the free-text fields of the anesthesia records that would be indicative of a tachyarrhythmia. Each case was reviewed by at least two authors; each patient was assigned a diagnosis classification of "highly suspicious" or "unlikely" SVT. The highly suspicious SVT cases were examined in detail to determine the specific aims. 36 subjects out of a total of 285,353 anesthetics administered during the study period were suspected by the anesthesia care team to have had an episode of intraoperative SVT: 22 were "highly suspicious" events, and 14 were "unlikely" events. The highly suspicious SVT events occurred in all phases of anesthesia, and none led to any hemodynamic instability. Effective treatments included vagal maneuvers, pharmacologic antiarrhythmics, or no treatment if the event resolved spontaneously before treatment. Six patients had outpatient follow-up and three received antiarrhythmic medications to control ongoing SVT. SVT during the intraoperative period in noncardiac pediatric patients was uncommon. When it occurred, it was not associated with clinically significant patient morbidity. For some patients, the anesthesia unmasked a predisposition for re-entrant SVT and those patients remained on maintenance antiarrhythmic therapy following discharge home.

Pediatric Health, 2010

Heart failure is becoming an increasingly common and significant problem in the field of pediatri... more Heart failure is becoming an increasingly common and significant problem in the field of pediatric cardiology. The numerous types of cardiomyopathies, and more recently, long-term survival of patients with congenital heart disease, have added to a growing patient population. Over the last several decades, our knowledge base regarding mechanisms of disease and therapeutic intervention in adult patients with heart failure has drastically changed. The most recent and important breakthrough in the pharmacologic treatment of heart failure has been the particular role of β-blocker therapy. This medication has led to significant improvements in survival and symptoms in adults, with less convincing findings in limited studies in pediatrics. The ability to study the benefits of this therapy in patients has been challenging owing to the heterogeneity of the patient population and lack of large sample sizes. However, as we investigate the mechanisms behind the disease process, the differences that exist between disease conditions and ages, and the significant alterations that may exist at the molecular and genetic level, our understanding of β-blocker therapy in pediatric heart failure will improve, and ultimately may lead to patient-specific therapy.

Pediatric Health, 2010

Heart failure is becoming an increasingly common and significant problem in the field of pediatri... more Heart failure is becoming an increasingly common and significant problem in the field of pediatric cardiology. The numerous types of cardiomyopathies, and more recently, long-term survival of patients with congenital heart disease, have added to a growing patient population. Over the last several decades, our knowledge base regarding mechanisms of disease and therapeutic intervention in adult patients with heart failure has drastically changed. The most recent and important breakthrough in the pharmacologic treatment of heart failure has been the particular role of β-blocker therapy. This medication has led to significant improvements in survival and symptoms in adults, with less convincing findings in limited studies in pediatrics. The ability to study the benefits of this therapy in patients has been challenging owing to the heterogeneity of the patient population and lack of large sample sizes. However, as we investigate the mechanisms behind the disease process, the differences that exist between disease conditions and ages, and the significant alterations that may exist at the molecular and genetic level, our understanding of β-blocker therapy in pediatric heart failure will improve, and ultimately may lead to patient-specific therapy.

Pediatric Cardiology, 2011

A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showe... more A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showed junctional tachycardia. Lyme titers were positive and the arrhythmia resolved with intravenous ceftriaxone.

Pediatric Cardiology, 2014

Radiation exposure during pediatric catheterization is significant. We sought to describe radiati... more Radiation exposure during pediatric catheterization is significant. We sought to describe radiation exposure and the effectiveness of radiation safety protocols in reducing exposure during catheter ablations with electrophysiology studies in children and patients with congenital heart disease. We additionally sought to identify at-risk patients. We retrospectively reviewed all interventional electrophysiology procedures performed from April 2009 to September 2011 (6 months preceding intervention, 12 months following implementation of initial radiation safety protocol, and 8 months following implementation of modified protocol). The protocols consisted of low pulse rate fluoroscopy settings, operator notification of skin entrance dose every 1,000 mGy, adjusting cameras by >5 at every 1,000 mGy, and appropriate collimation. The cohort consisted of 291 patients (70 pre-intervention, 137 after initial protocol implementation, 84 after modified protocol implementation) at a median age of 14.9 years with congenital heart disease present in 11 %. Diagnoses included atrioventricular nodal reentrant tachycardia (25 %), atrioventricular reentrant tachycardia (61 %), atrial tachycardias (12 %), and ventricular tachycardia (2 %). There were no differences between groups based on patient, arrhythmia, and procedural characteristics. Following implementation of the protocols, there were significant reductions in all measures of radiation exposure: fluoroscopy time (17.8 %), dose area product (80.2 %), skin entry dose (81.0 %), and effective dose (76.9 %), p = 0.0001. Independent predictors of increased radiation exposure included larger patient weight, longer fluoroscopy time, and lack of radiation safety protocol. Implementation of a radiation safety protocol for pediatric and congenital catheter ablations can drastically reduce radiation exposure to patients without affecting procedural success.

Pediatric Cardiology, 2011

A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showe... more A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showed junctional tachycardia. Lyme titers were positive and the arrhythmia resolved with intravenous ceftriaxone.

Pediatric Cardiology, 2014

Journal of the American College of Cardiology, 2013

Cardiology in the Young, 2011

Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent ... more Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent coronary circulation is a well-established complication, and is thought to be caused by myocardial ischaemia. We report a case of paroxysmal complete atrioventricular block that raises the possibility of an additional mechanism of sudden death.

Cardiology in the Young, 2012

Myocardial ischaemia and infarction in pulmonary atresia and intact ventricular septum with right... more Myocardial ischaemia and infarction in pulmonary atresia and intact ventricular septum with right ventricular-dependent coronary circulation is a well-established complication. We report an interesting case of an acquired aneurysm in the ventricular septum in a patient who underwent staged palliation.

Neurosurgery, 2005

Although most pineal cysts are clinically benign and asymptomatic, some can become symptomatic. O... more Although most pineal cysts are clinically benign and asymptomatic, some can become symptomatic. Of the various symptomatic presentations, apoplexy is the rarest and most ill-defined. A comprehensive search of publications in the English language yielded 18 cases of pineal cyst apoplexy. We reviewed the literature to compare symptomatology and management strategies and their outcomes. A 29-year-old woman with a 1-month history of headaches presented with an acute worsening of her symptoms with a severe occipital headache and trouble focusing when reading. Her neurological examination was otherwise normal. Magnetic resonance imaging showed pineal cyst apoplexy and accompanying hydrocephalus. A left paramedian craniotomy with a transcallosal, transchoroidal approach using an intraoperative neuronavigation system was used to resect a pineal cyst. Postoperative imaging showed complete removal of the cyst and resolution of the hydrocephalus. Follow-up imaging at 12 months demonstrated no evidence of recurrence or any hydrocephalus. The patient has remained asymptomatic for 18 months. Pineal cyst apoplexy should always be considered when following a patient with a pineal cyst that becomes symptomatic. The most common symptom was severe headache of sudden onset or acute worsening. Other signs of hydrocephalus may or may not be present. Magnetic resonance imaging is essential to making a diagnosis. Although we believe that surgical resection is the most effective approach because it minimizes the risk for recurrence and complication, stereotactic aspiration has been used successfully to treat this condition.

Neurosurgery, 2008

Local recurrence (LR) of a resected brain metastasis occurs in up to 46% of patients. Postoperati... more Local recurrence (LR) of a resected brain metastasis occurs in up to 46% of patients. Postoperative whole-brain radiation therapy (WBRT) reduces that incidence. To isolate factors associated with the risk of LR after resection, the authors only studied patients who did not receive adjuvant radiotherapy. The authors reviewed data from 570 cases involving patients who had undergone resection of a previously untreated single brain metastasis at The University of Texas M. D. Anderson Cancer Center between 1993 and 2006 without receiving postoperative WBRT. All tumors were measured preoperatively on MR images. The resection method (en bloc resection [EBR] or piecemeal resection [PMR]) was noted at the time of surgery. Predictors of LR were assessed using the Cox proportional hazards model. The median patient age was 58 years, 55% were male, and 88% had a Karnofsky Performance Scale Score > or = 80. The most common primary cancers were those of the lung (28%), skin (melanoma, 21%), kidney (19%), and breast (11%). Piecemeal resection was performed in 201 patients (35%) and EBR in 369 (65%). Local recurrence developed in 84 patients (15%). The histological type of the primary cancer did not significantly predict LR; however, 7 of 22 patients with sarcoma developed LR (p = 0.16). The authors identified 2 variables that increased the risk of LR. Undergoing PMR carried a significantly higher LR risk than EBR (crude hazard ratio [HR] 1.7, 95% CI 1.1-2.6, p = 0.03). Tumors exceeding the median volume (9.7 cm(3)) had a significantly higher LR risk than those that were < 9.7 cm(3) (crude HR 1.7; 95% CI 1.1-2.6; p = 0.02). In the multivariate analysis, small tumors removed by EBR had a significantly lower LR risk. The LR risk of a single brain metastasis is influenced by biological factors (such as tumor volume) and treatments (such as the resection method). Early administration of postoperative WBRT may be particularly warranted when such negative tumor-related prognostic factors are noted or when treatment-related ones such as PMR are unavoidable.

Journal of Neurosurgery: Pediatrics, 2011

Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt ... more Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

Journal of Clinical Neuroscience, 2014

This study aimed to determine if partial removal of the occipital condyle provides a significant ... more This study aimed to determine if partial removal of the occipital condyle provides a significant increase in visibility and "angle of attack" for treating lesions with extension ventral to the brainstem in children using CT morphometric data. Morphometric analysis was performed in 199 children using CT scans. Angle of attack was measured for both the paracondylar and transcondylar far lateral approach. Statistical analysis was performed using paired or unpaired Student's t-tests (p<0.05) and linear regression analysis. For the far lateral paracondylar approach, the overall angle of attack was 85 ± 9 degrees (range, 60-119 degrees). The overall angle of attack for the far lateral transcondylar approach was 70 ± 9 degrees (range, 48-105 degrees). This difference was significant (p<0.0001). Based on our data, resection of one-third of the occipital condyle in a far lateral transcondylar approach can improve angle of attack by approximately 15 degrees, regardless of age or sex, in the pediatric age group. It is important to keep in mind that there are risks attendant to resection of the occipital condyle, thus the resection of the occipital condyle in children should not be a mandatory part of the far lateral approach; rather, the decision-making should be individualized and considered on a case-by-case basis.

Journal of Neurosurgery: Pediatrics, 2014

Cranial osteosarcoma is very rare in children, rendering the development of optimal treatment alg... more Cranial osteosarcoma is very rare in children, rendering the development of optimal treatment algorithms challenging. The authors present 3 cases of pediatric cranial osteosarcoma: a primary calvarial tumor, a cranial metastasis, and a primary osteosarcoma of the cranial base. A review of the literature demonstrates significant variation in the management of cranial osteosarcomas and the outcome for patients with these tumors. This series and literature review is presented to improve the understanding of pediatric cranial osteosarcoma and to reinforce the importance of maximal resection in optimizing outcome.

Journal of Neurosurgery, 2014

Prediction of outcome from initial presentation after a gunshot wound to the head (GSWH) is essen... more Prediction of outcome from initial presentation after a gunshot wound to the head (GSWH) is essential to further clinical decision making. The authors' goals are to report the survival and functional outcomes of these patients, to identify prognostic factors, and to propose a scoring system that can predict their outcome. The records of 199 patients admitted with a GSWH with dural penetration between 1990 and 2008 were retrospectively reviewed. The inclusion criterion was a CT scan available for review. Patients declared brain dead on presentation were excluded, which yielded a series of 119 patients. Statistical analysis was performed using a logistic regression model. Fifty-eight (49%) of the 119 patients died. Twenty-three patients (19%) had a favorable outcome defined as a 6-month Glasgow Outcome Scale (GOS) score of moderate disability or good recovery, 35 (29%) had a poor outcome (GOS of persistent vegetative state or severe disability), and 3 (3%) were lost to follow-up. Significant prognostic factors for mortality were age older than 35 years, nonreactive pupils, bullet trajectory of bihemispheric (excluding bifrontal), and posterior fossa involvement compared with unihemispheric and bifrontal. Factors that were moderately associated with higher mortality included intracranial pressure (ICP) above 20 mm Hg and Glasgow Coma Scale (GCS) score at presentation of 3 or 4. Upon multivariate analysis, the significant factors for mortality were bullet trajectory and pupillary response. Variables found to be significant for good functional outcome were admission GCS score greater than or equal to 5, pupillary reactivity, and bullet trajectory of unihemispheric or bifrontal. Factors moderately associated with good outcome included age of 35 years or younger, initial ICP 20 mm Hg or lower, and lack of transventricular trajectory. In the multivariate analysis, significant factors for good functional outcome were bullet trajectory and pupillary response, with age moderately associated with improved functional outcomes. The authors also propose a scoring system to estimate survival and functional outcome. Age, pupils, GCS score, and bullet trajectory on CT scan can be used to determine likelihood of survival and good functional outcome. The authors advocate assessing patients based on these parameters rather than pronouncing a poor prognosis and withholding aggressive resuscitation based upon low GCS score alone.

Journal of Neurosurgery, 2009

Metastatic sarcoma to the brain is rare and represents a therapeutic challenge due to its relativ... more Metastatic sarcoma to the brain is rare and represents a therapeutic challenge due to its relative resistance to radio- and chemotherapy. Resection has traditionally been the mainstay of treatment. The authors reviewed a series of patients with metastatic sarcoma to the brain treated surgically to determine outcomes and identify predictors of survival in these patients. A retrospective review of prospectively collected data was undertaken on patients undergoing surgery between 1993 and 2005 for metastatic sarcoma to the brain at The University of Texas, M.D. Anderson Cancer Center. During the study period, 62 patients underwent 84 operations for metastatic sarcoma to the brain. The median postoperative overall and progression-free survival rates were 7.5 and 4.7 months, respectively. Fifty-nine (95%) of 62 patients had a gross-total resection. The 30-day mortality rate was 4.2%. The Karnofsky Performance Scale scores at discharge from the hospital and 3 months postoperatively were the same or improved in 50 (85%) of 59 and 26 (51%) of 51, respectively. Overall postcraniotomy survival was 62% at 6 months, 39% at 1 year, 21% at 2 years, and 8% at 5 years. In multivariate and univariate analysis, control of systemic disease, and sarcomas originating from bone, cartilage, or soft tissue were predictors of survival. Patients with control of systemic disease had survival advantage when compared with those who did not. In patients with alveolar soft-part sarcoma, there was a significantly increased survival advantage compared with all other histological subgroups. The authors' results suggest that in selected patients, resection of metastatic sarcoma to the brain is associated with a relatively low risk of operative death and results in improvement in neurological function. Patients with systemic control of their primary disease and certain histological subtypes (specifically alveolar soft-part sarcoma) have improved overall and progression-free survival.

The American Journal of Cardiology, 2014

Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arter... more Electrocardiograms have utility in disease stratification and monitoring in adult pulmonary arterial hypertension (PAH). We examined the electrocardiographic findings that are common in pediatric PAH and assessed for correlation with disease severity and progression. We retrospectively identified patients aged≤18 years followed at a single institution from January 2001 to June 2012 with catheterization-confirmed diagnosis of idiopathic PAH and PAH secondary to pulmonary developmental abnormalities. Patients with an electrocardiography performed within 60 days of catheterization were included. Primary and secondary outcomes are the prevalence of abnormal electrocardiographic findings at the time of catheterization and the association between electrocardiographic and hemodynamic findings and electrocardiographic changes with disease progression on follow-up catheterization, respectively. Of the 100 electrocardiography-catheterization pairs derived from the 46 patients identified, 93% had an electrocardiographic abnormality: 78% had right ventricular hypertrophy (RVH) and 52% had right axis deviation (RAD) for age. In patients with idiopathic PAH, the presence of RVH and RAD correlated with pulmonary vascular resistance and transpulmonary gradient. RAD and RVH on baseline electrocardiogram was associated with an increased risk of disease progression on subsequent catheterization (odds ratio 11.0, 95% confidence interval 1.3 to 96.2, p=0.03) after adjusting for PAH subgroup. The sensitivity, specificity, and positive and negative predictive values of RAD and RVH on baseline electrocardiogram for disease progression were 92%, 48%, 33%, and 95%, respectively. In conclusion, electrocardiographic abnormalities are common in pediatric PAH. RAD and RVH on electrocardiogram were associated with worse hemodynamics, whereas their absence is suggestive of a lack of disease progression.

Moller/Pediatric Cardiovascular Medicine, 2012

ABSTRACT Heart failure in children is an increasingly recognized clinical entity. Etiologies are ... more ABSTRACT Heart failure in children is an increasingly recognized clinical entity. Etiologies are diverse and treatment options are expanding. Although the evidence base for the treatment of heart failure in adults is well developed, much less is known about the efficacy of available treatments in children with heart failure. This chapter focuses on the mechanisms, etiologies, treatment options, and outcomes in children with heart failure secondary to systemic ventricular dysfunction.

Journal of Clinical Anesthesia, 2014

To perform a qualitative analysis of noncardiac patients who developed suspected intraoperative s... more To perform a qualitative analysis of noncardiac patients who developed suspected intraoperative supraventricular tachycardia (SVT) during general anesthesia. Retrospective database analysis and chart review. Operating room of a university-affiliated children's hospital. The records of children without cardiac disease who received general anesthesia at The Children's Hospital of Philadelphia from July 1998 through June 2011 were reviewed. Patients with heart rate values above 180 beats per minute were identified, as were specific medications or key words in the free-text fields of the anesthesia records that would be indicative of a tachyarrhythmia. Each case was reviewed by at least two authors; each patient was assigned a diagnosis classification of "highly suspicious" or "unlikely" SVT. The highly suspicious SVT cases were examined in detail to determine the specific aims. 36 subjects out of a total of 285,353 anesthetics administered during the study period were suspected by the anesthesia care team to have had an episode of intraoperative SVT: 22 were "highly suspicious" events, and 14 were "unlikely" events. The highly suspicious SVT events occurred in all phases of anesthesia, and none led to any hemodynamic instability. Effective treatments included vagal maneuvers, pharmacologic antiarrhythmics, or no treatment if the event resolved spontaneously before treatment. Six patients had outpatient follow-up and three received antiarrhythmic medications to control ongoing SVT. SVT during the intraoperative period in noncardiac pediatric patients was uncommon. When it occurred, it was not associated with clinically significant patient morbidity. For some patients, the anesthesia unmasked a predisposition for re-entrant SVT and those patients remained on maintenance antiarrhythmic therapy following discharge home.

Pediatric Health, 2010

Heart failure is becoming an increasingly common and significant problem in the field of pediatri... more Heart failure is becoming an increasingly common and significant problem in the field of pediatric cardiology. The numerous types of cardiomyopathies, and more recently, long-term survival of patients with congenital heart disease, have added to a growing patient population. Over the last several decades, our knowledge base regarding mechanisms of disease and therapeutic intervention in adult patients with heart failure has drastically changed. The most recent and important breakthrough in the pharmacologic treatment of heart failure has been the particular role of β-blocker therapy. This medication has led to significant improvements in survival and symptoms in adults, with less convincing findings in limited studies in pediatrics. The ability to study the benefits of this therapy in patients has been challenging owing to the heterogeneity of the patient population and lack of large sample sizes. However, as we investigate the mechanisms behind the disease process, the differences that exist between disease conditions and ages, and the significant alterations that may exist at the molecular and genetic level, our understanding of β-blocker therapy in pediatric heart failure will improve, and ultimately may lead to patient-specific therapy.

Pediatric Health, 2010

Heart failure is becoming an increasingly common and significant problem in the field of pediatri... more Heart failure is becoming an increasingly common and significant problem in the field of pediatric cardiology. The numerous types of cardiomyopathies, and more recently, long-term survival of patients with congenital heart disease, have added to a growing patient population. Over the last several decades, our knowledge base regarding mechanisms of disease and therapeutic intervention in adult patients with heart failure has drastically changed. The most recent and important breakthrough in the pharmacologic treatment of heart failure has been the particular role of β-blocker therapy. This medication has led to significant improvements in survival and symptoms in adults, with less convincing findings in limited studies in pediatrics. The ability to study the benefits of this therapy in patients has been challenging owing to the heterogeneity of the patient population and lack of large sample sizes. However, as we investigate the mechanisms behind the disease process, the differences that exist between disease conditions and ages, and the significant alterations that may exist at the molecular and genetic level, our understanding of β-blocker therapy in pediatric heart failure will improve, and ultimately may lead to patient-specific therapy.

Pediatric Cardiology, 2011

A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showe... more A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showed junctional tachycardia. Lyme titers were positive and the arrhythmia resolved with intravenous ceftriaxone.

Pediatric Cardiology, 2014

Radiation exposure during pediatric catheterization is significant. We sought to describe radiati... more Radiation exposure during pediatric catheterization is significant. We sought to describe radiation exposure and the effectiveness of radiation safety protocols in reducing exposure during catheter ablations with electrophysiology studies in children and patients with congenital heart disease. We additionally sought to identify at-risk patients. We retrospectively reviewed all interventional electrophysiology procedures performed from April 2009 to September 2011 (6 months preceding intervention, 12 months following implementation of initial radiation safety protocol, and 8 months following implementation of modified protocol). The protocols consisted of low pulse rate fluoroscopy settings, operator notification of skin entrance dose every 1,000 mGy, adjusting cameras by >5 at every 1,000 mGy, and appropriate collimation. The cohort consisted of 291 patients (70 pre-intervention, 137 after initial protocol implementation, 84 after modified protocol implementation) at a median age of 14.9 years with congenital heart disease present in 11 %. Diagnoses included atrioventricular nodal reentrant tachycardia (25 %), atrioventricular reentrant tachycardia (61 %), atrial tachycardias (12 %), and ventricular tachycardia (2 %). There were no differences between groups based on patient, arrhythmia, and procedural characteristics. Following implementation of the protocols, there were significant reductions in all measures of radiation exposure: fluoroscopy time (17.8 %), dose area product (80.2 %), skin entry dose (81.0 %), and effective dose (76.9 %), p = 0.0001. Independent predictors of increased radiation exposure included larger patient weight, longer fluoroscopy time, and lack of radiation safety protocol. Implementation of a radiation safety protocol for pediatric and congenital catheter ablations can drastically reduce radiation exposure to patients without affecting procedural success.

Pediatric Cardiology, 2011

A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showe... more A 3-year-old girl presented with fatigue, fever, and rash. Tachycardia was noted and an ECG showed junctional tachycardia. Lyme titers were positive and the arrhythmia resolved with intravenous ceftriaxone.

Pediatric Cardiology, 2014

Journal of the American College of Cardiology, 2013

Cardiology in the Young, 2011

Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent ... more Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent coronary circulation is a well-established complication, and is thought to be caused by myocardial ischaemia. We report a case of paroxysmal complete atrioventricular block that raises the possibility of an additional mechanism of sudden death.

Cardiology in the Young, 2012

Myocardial ischaemia and infarction in pulmonary atresia and intact ventricular septum with right... more Myocardial ischaemia and infarction in pulmonary atresia and intact ventricular septum with right ventricular-dependent coronary circulation is a well-established complication. We report an interesting case of an acquired aneurysm in the ventricular septum in a patient who underwent staged palliation.

Neurosurgery, 2005

Although most pineal cysts are clinically benign and asymptomatic, some can become symptomatic. O... more Although most pineal cysts are clinically benign and asymptomatic, some can become symptomatic. Of the various symptomatic presentations, apoplexy is the rarest and most ill-defined. A comprehensive search of publications in the English language yielded 18 cases of pineal cyst apoplexy. We reviewed the literature to compare symptomatology and management strategies and their outcomes. A 29-year-old woman with a 1-month history of headaches presented with an acute worsening of her symptoms with a severe occipital headache and trouble focusing when reading. Her neurological examination was otherwise normal. Magnetic resonance imaging showed pineal cyst apoplexy and accompanying hydrocephalus. A left paramedian craniotomy with a transcallosal, transchoroidal approach using an intraoperative neuronavigation system was used to resect a pineal cyst. Postoperative imaging showed complete removal of the cyst and resolution of the hydrocephalus. Follow-up imaging at 12 months demonstrated no evidence of recurrence or any hydrocephalus. The patient has remained asymptomatic for 18 months. Pineal cyst apoplexy should always be considered when following a patient with a pineal cyst that becomes symptomatic. The most common symptom was severe headache of sudden onset or acute worsening. Other signs of hydrocephalus may or may not be present. Magnetic resonance imaging is essential to making a diagnosis. Although we believe that surgical resection is the most effective approach because it minimizes the risk for recurrence and complication, stereotactic aspiration has been used successfully to treat this condition.

Neurosurgery, 2008

Local recurrence (LR) of a resected brain metastasis occurs in up to 46% of patients. Postoperati... more Local recurrence (LR) of a resected brain metastasis occurs in up to 46% of patients. Postoperative whole-brain radiation therapy (WBRT) reduces that incidence. To isolate factors associated with the risk of LR after resection, the authors only studied patients who did not receive adjuvant radiotherapy. The authors reviewed data from 570 cases involving patients who had undergone resection of a previously untreated single brain metastasis at The University of Texas M. D. Anderson Cancer Center between 1993 and 2006 without receiving postoperative WBRT. All tumors were measured preoperatively on MR images. The resection method (en bloc resection [EBR] or piecemeal resection [PMR]) was noted at the time of surgery. Predictors of LR were assessed using the Cox proportional hazards model. The median patient age was 58 years, 55% were male, and 88% had a Karnofsky Performance Scale Score > or = 80. The most common primary cancers were those of the lung (28%), skin (melanoma, 21%), kidney (19%), and breast (11%). Piecemeal resection was performed in 201 patients (35%) and EBR in 369 (65%). Local recurrence developed in 84 patients (15%). The histological type of the primary cancer did not significantly predict LR; however, 7 of 22 patients with sarcoma developed LR (p = 0.16). The authors identified 2 variables that increased the risk of LR. Undergoing PMR carried a significantly higher LR risk than EBR (crude hazard ratio [HR] 1.7, 95% CI 1.1-2.6, p = 0.03). Tumors exceeding the median volume (9.7 cm(3)) had a significantly higher LR risk than those that were < 9.7 cm(3) (crude HR 1.7; 95% CI 1.1-2.6; p = 0.02). In the multivariate analysis, small tumors removed by EBR had a significantly lower LR risk. The LR risk of a single brain metastasis is influenced by biological factors (such as tumor volume) and treatments (such as the resection method). Early administration of postoperative WBRT may be particularly warranted when such negative tumor-related prognostic factors are noted or when treatment-related ones such as PMR are unavoidable.

Journal of Neurosurgery: Pediatrics, 2011

Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt ... more Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

Journal of Clinical Neuroscience, 2014

This study aimed to determine if partial removal of the occipital condyle provides a significant ... more This study aimed to determine if partial removal of the occipital condyle provides a significant increase in visibility and "angle of attack" for treating lesions with extension ventral to the brainstem in children using CT morphometric data. Morphometric analysis was performed in 199 children using CT scans. Angle of attack was measured for both the paracondylar and transcondylar far lateral approach. Statistical analysis was performed using paired or unpaired Student's t-tests (p<0.05) and linear regression analysis. For the far lateral paracondylar approach, the overall angle of attack was 85 ± 9 degrees (range, 60-119 degrees). The overall angle of attack for the far lateral transcondylar approach was 70 ± 9 degrees (range, 48-105 degrees). This difference was significant (p<0.0001). Based on our data, resection of one-third of the occipital condyle in a far lateral transcondylar approach can improve angle of attack by approximately 15 degrees, regardless of age or sex, in the pediatric age group. It is important to keep in mind that there are risks attendant to resection of the occipital condyle, thus the resection of the occipital condyle in children should not be a mandatory part of the far lateral approach; rather, the decision-making should be individualized and considered on a case-by-case basis.

Journal of Neurosurgery: Pediatrics, 2014

Cranial osteosarcoma is very rare in children, rendering the development of optimal treatment alg... more Cranial osteosarcoma is very rare in children, rendering the development of optimal treatment algorithms challenging. The authors present 3 cases of pediatric cranial osteosarcoma: a primary calvarial tumor, a cranial metastasis, and a primary osteosarcoma of the cranial base. A review of the literature demonstrates significant variation in the management of cranial osteosarcomas and the outcome for patients with these tumors. This series and literature review is presented to improve the understanding of pediatric cranial osteosarcoma and to reinforce the importance of maximal resection in optimizing outcome.

Journal of Neurosurgery, 2014

Prediction of outcome from initial presentation after a gunshot wound to the head (GSWH) is essen... more Prediction of outcome from initial presentation after a gunshot wound to the head (GSWH) is essential to further clinical decision making. The authors' goals are to report the survival and functional outcomes of these patients, to identify prognostic factors, and to propose a scoring system that can predict their outcome. The records of 199 patients admitted with a GSWH with dural penetration between 1990 and 2008 were retrospectively reviewed. The inclusion criterion was a CT scan available for review. Patients declared brain dead on presentation were excluded, which yielded a series of 119 patients. Statistical analysis was performed using a logistic regression model. Fifty-eight (49%) of the 119 patients died. Twenty-three patients (19%) had a favorable outcome defined as a 6-month Glasgow Outcome Scale (GOS) score of moderate disability or good recovery, 35 (29%) had a poor outcome (GOS of persistent vegetative state or severe disability), and 3 (3%) were lost to follow-up. Significant prognostic factors for mortality were age older than 35 years, nonreactive pupils, bullet trajectory of bihemispheric (excluding bifrontal), and posterior fossa involvement compared with unihemispheric and bifrontal. Factors that were moderately associated with higher mortality included intracranial pressure (ICP) above 20 mm Hg and Glasgow Coma Scale (GCS) score at presentation of 3 or 4. Upon multivariate analysis, the significant factors for mortality were bullet trajectory and pupillary response. Variables found to be significant for good functional outcome were admission GCS score greater than or equal to 5, pupillary reactivity, and bullet trajectory of unihemispheric or bifrontal. Factors moderately associated with good outcome included age of 35 years or younger, initial ICP 20 mm Hg or lower, and lack of transventricular trajectory. In the multivariate analysis, significant factors for good functional outcome were bullet trajectory and pupillary response, with age moderately associated with improved functional outcomes. The authors also propose a scoring system to estimate survival and functional outcome. Age, pupils, GCS score, and bullet trajectory on CT scan can be used to determine likelihood of survival and good functional outcome. The authors advocate assessing patients based on these parameters rather than pronouncing a poor prognosis and withholding aggressive resuscitation based upon low GCS score alone.