Johns Hopkins All Children's Hospital

Meet Our Vascular Anomalies Team

The pediatric vascular anomalies team at Johns Hopkins All Children's includes experts from across specialties who work together to treat children and teens.

The Vascular Anomalies team at Johns Hopkins All Children’s Hospital uses a comprehensive approach that brings together specialists from multiple disciplines to address your child’s individual needs, often including:

Cardiology
Endocrinology
Gastroenterology
General Surgery
Genetics
Hematology/Oncology
Interventional Radiology
Neurosurgery

Ophthalmology
Orthopedics
Otolaryngology
Pathology
Physiatry
Plastic and Reconstructive Surgery
Psychology
Pulmonology

Leadership

Jennifer Mayer, MD — Jennifer Mayer, MD
Pediatric Oncology

Dr. Mayer specializes in pediatric hematology/oncology in the Johns Hopkins All Children’s Cancer & Blood Disorders Institute and is the lead hematologist of the Vascular Anomalies Program at the hospital. She served 21 years as medical director of Johns Hopkins All Children’s collaboration with Sarasota Memorial Hospital. She is author of more than 30 publications and two textbook chapters. She joined Johns Hopkins All Children's in 1996 and received the hospital's Best Consulting Physician Award in the 2017 Johns Hopkins Medicine Clinical Excellence Awards.
View Jennifer Mayer’s Bio

S. Alex Rottgers, MD — S. Alex Rottgers, MD
Plastic Surgery

Dr. Rottgers practices in the pediatric plastic and craniofacial surgery programs and is chief of the division of plastic and reconstructive surgery at Johns Hopkins All Children’s Hospital. His areas of special interest are vascular anomalies and in the treatment of cleft and craniofacial conditions including cleft lip and palate, craniosynostosis, hemifacial microsomia, microtia, and other abnormalities of the face and jaw.
View S. Alex Rottgers’s Bio

Paul Danielson, MD — Paul Danielson, MD
Pediatric Surgery

Dr. Danielson became chair of the Johns Hopkins All Children's Department of Surgery in 2020 after serving in that role on an interim basis beginning in December 2018. He specializes in general surgery and was an early adopter of minimally invasive surgical techniques, developing expertise in treating chest wall deformities. He founded the first fellowship sponsored by Johns Hopkins All Children’s Hospital in pediatric surgery and was also instrumental in bringing the National Quality Improvement in Surgery Program to the institution. Dr. Danielson was named Johns Hopkins All Children’s Hospital physician of the year in the 2015 Johns Hopkins Medicine Clinical Excellence Awards and in 2017 was named director of innovative training and education. He is a retired U.S. Army officer.
View Paul Danielson’s Bio

Hematology

Jennifer Mayer, MD — Jennifer Mayer, MD
Pediatric Oncology

Dr. Mayer specializes in pediatric hematology/oncology in the Johns Hopkins All Children’s Cancer & Blood Disorders Institute and is the lead hematologist of the Vascular Anomalies Program at the hospital. She served 21 years as medical director of Johns Hopkins All Children’s collaboration with Sarasota Memorial Hospital. She is author of more than 30 publications and two textbook chapters. She joined Johns Hopkins All Children's in 1996 and received the hospital's Best Consulting Physician Award in the 2017 Johns Hopkins Medicine Clinical Excellence Awards.
View Jennifer Mayer’s Bio

Plastic Surgery

S. Alex Rottgers, MD — S. Alex Rottgers, MD
Plastic Surgery

Dr. Rottgers practices in the pediatric plastic and craniofacial surgery programs and is chief of the division of plastic and reconstructive surgery at Johns Hopkins All Children’s Hospital. His areas of special interest are vascular anomalies and in the treatment of cleft and craniofacial conditions including cleft lip and palate, craniosynostosis, hemifacial microsomia, microtia, and other abnormalities of the face and jaw.
View S. Alex Rottgers’s Bio

Jordan Halsey, MD — Jordan Halsey, MD
Plastic and Reconstructive Surgery

Dr. Halsey is a pediatric plastic surgeon at Johns Hopkins All Children’s Hospital and an assistant professor in the Johns Hopkins University School of Medicine Department of Plastic and Reconstructive Surgery. She joined the hospital staff in 2021. Dr. Halsey earned her medical degree from the University of Tennessee Health Science Center College of Medicine in Memphis, Tennessee. She completed a residency in integrated plastic surgery from Rutgers-New Jersey Medical School in Newark, New Jersey, where she was administrative chief resident. She then completed a fellowship in pediatric craniofacial surgery from Nationwide Children’s Hospital in Columbus, Ohio.
View Jordan Halsey’s Bio

Radiology

Michael Collard, MD — Michael Collard, MD
Pediatric Radiology

Dr. Collard specializes in pediatric interventional radiology at Johns Hopkins All Children’s Hospital. He joined the medical staff in 2021. Dr. Collard earned his medical degree from the University of Missouri Kansas City School of Medicine in Kansas City, Missouri. He completed an internship in internal medicine at the University of Missouri Kansas City School of Medicine and a residency in diagnostic radiology at the University of Texas Southwestern Medical Center in Dallas. He then completed a fellowship in vascular and interventional radiology at Massachusetts General Hospital/Harvard Medical School in Boston, followed by a fellowship in pediatric radiology with an emphasis in interventional radiology at Boston Children’s Hospital/Harvard Medical School.
View Michael Collard’s Bio

Christopher Francis, MD — Christopher Francis, MD
Interventional Radiology

Dr. Francis specializes in adult and pediatric interventional radiology. He is an assistant professor of Radiology in the University of South Florida (USF) Morsani College of Medicine. He joined the Johns Hopkins All Children’s medical staff in 2018.
View Christopher Francis’s Bio

Sally Mitchell, MD — Sally Mitchell, MD
Interventional Radiology

Dr. Mitchell is an interventional radiologist at Johns Hopkins All Children’s. She joined the hospital staff in 2021. She was most recently director of pediatric interventional radiology and director of vascular anomalies interventional radiology at Johns Hopkins University School of Medicine in Baltimore.
View Sally Mitchell’s Bio

Surgery

Paul Danielson, MD — Paul Danielson, MD
Pediatric Surgery

Dr. Danielson became chair of the Johns Hopkins All Children's Department of Surgery in 2020 after serving in that role on an interim basis beginning in December 2018. He specializes in general surgery and was an early adopter of minimally invasive surgical techniques, developing expertise in treating chest wall deformities. He founded the first fellowship sponsored by Johns Hopkins All Children’s Hospital in pediatric surgery and was also instrumental in bringing the National Quality Improvement in Surgery Program to the institution. Dr. Danielson was named Johns Hopkins All Children’s Hospital physician of the year in the 2015 Johns Hopkins Medicine Clinical Excellence Awards and in 2017 was named director of innovative training and education. He is a retired U.S. Army officer.
View Paul Danielson’s Bio

Ophthalmology

Derek Hess, MD — Derek Hess, MD
Ophthalmology

Dr. Hess specializes in pediatric ophthalmology in the Johns Hopkins All Children’s Department of Pediatric Medicine. He served as chief of the medical staff from 2017-2019. He joined the Johns Hopkins All Children’s Hospital medical staff in 2004. Dr. Hess earned his medical degree from the University of South Florida Morsani College of Medicine in Tampa, Florida. He trained as an ophthalmology resident at Medical College of Virginia and completed a pediatric ophthalmology fellowship at Duke University Eye Center.
View Derek Hess’s Bio

ENT / Otolaryngology

Rose Trowbridge, MD — Rose Trowbridge, MD
Otolaryngology

Dr. Trowbridge is a pediatric ear, nose and throat surgeon at Johns Hopkins All Children’s Hospital. She sees patients in the Brandon, Clearwater, Odessa, Sarasota, and Tampa locations of Pediatric Otolaryngology Head & Neck Surgery Associates, PA and the Johns Hopkins All Children’s Outpatient Care location in St. Petersburg.
View Rose Trowbridge’s Bio

Kathleen Wasylik, MD — Kathleen Wasylik, MD
Otolaryngology

Dr. Wasylik is a pediatric ear, nose and throat surgeon at Johns Hopkins All Children’s Hospital. She sees patients in the Brandon, Clearwater, Odessa, Sarasota, and Tampa locations of Pediatric Otolaryngology Head & Neck Surgery Associates, PA and the Johns Hopkins All Children’s Outpatient Care location in St. Petersburg.
View Kathleen Wasylik’s Bio

Orthopaedics

Lee Phillips, MD — Lee Phillips, MD
Orthopaedic Surgery

Dr. Phillips is a pediatric orthopaedic surgeon at Johns Hopkins All Children’s Hospital. He sees patients in the St. Petersburg and Tampa locations of Children's Orthopaedic and Scoliosis Surgery Associates (COSSA), L.L.P., and Johns Hopkins All Children’s Outpatient Care, Sarasota.
View Lee Phillips’s Bio

Cardiology

Marguerite Crawford, MD — Marguerite Crawford, MD
Pediatric Cardiology

Dr. Crawford is a general pediatric cardiologist and director of cardiac MRI (magnetic resonance imaging) imaging at the Johns Hopkins All Children’s Heart Institute. She is an assistant professor of pediatrics with the Johns Hopkins University School of Medicine. After graduating from the University of Louisville School of Medicine, she completed a pediatric residency, served as chief pediatric resident and then did her pediatric cardiology fellowship at the University of Virginia. Dr. Crawford obtained additional training in cardiac MRI imaging during her fellowship at Virginia and also was a fellow in cardiac MRI at Children’s Hospital Boston.
View Marguerite Crawford’s Bio

Michelle Miller, MD — Michelle Miller, MD
Pediatric Cardiology

Dr. Miller specializes in pediatric, fetal and adult congenital heart disease, with a particular focus in fetal medicine. She works closely with prenatal practitioners throughout the area to offer safe, well-planned pregnancies and deliveries and educates local pediatric caregivers and community hospitals in caring for children and pregnant women with cardiac issues. After completing her pediatric cardiology fellowship at UCLA, Miller became the director of fetal cardiology at Cedars-Sinai Medical Center in Los Angeles and an associate professor of medicine in the UCLA Department of Pediatrics. Having relocated to Florida in 2010, Dr. Miller is an associate professor of medicine with the Florida State University Medical School. She has published multiple scholarly articles on pediatric and fetal cardiology. Recently, Dr. Miller began cataloging the cardiac pathology library at Johns Hopkins All Children’s Hospital, a project that will make a significant contribution to education and research.
View Michelle Miller’s Bio

Endocrinology

Allen Root, MD — Allen Root, MD
Pediatric Endocrinology

Dr. Root is a pediatric endocrinologist. A graduate of Harvard Medical School, Dr. Root completed his internship at Strong Memorial Hospital, Rochester, NY and his pediatric residency at University of Pennsylvania, followed by a fellowship in pediatric endocrinology at Children's Hospital of Philadelphia, University of Pennsylvania. After serving on the medical faculty of the University of Pennsylvania and Temple University, Dr. Root joined the University of South Florida College of Medicine in 1973, serving as professor of pediatrics, associate and vice-chair of the Department of Pediatrics, and director of the pediatric residency program.
View Allen Root’s Bio

Genetics

Melissa Crenshaw, MD — Melissa Crenshaw, MD
Medical Genetics

Dr. Crenshaw is the medical director for the Clinical Genetics Program at Johns Hopkins All Children’s Hospital and also serves as an assistant professor with Johns Hopkins Medicine. Her research interests include congenital heart defects, chromosome abnormalities and Turner Syndrome. She has additional expertise in the genetics of congenital heart disease and connective tissue disorders. Dr. Crenshaw is board certified in pediatrics and clinical genetics.
View Melissa Crenshaw’s Bio

Pathology

Ignacio Gonzalez-Gomez, MD — Ignacio Gonzalez-Gomez, MD
Anatomic and Clinical Pathology Pediatric Pathology

Dr. Gonzalez-Gomez is a pathologist at Johns Hopkins All Children’s Hospital. He joined the hospital staff in 2009. His research interests include pediatric neuropathology and in particular neuro-oncogenesis, the search for the etiology or processes that lead to the development of brain tumors, including cellular morphologic features, patterns of growth, immunophenotype, metabolism, proliferation, apoptosis/necrosis, vascularization and response to therapy.
View Ignacio Gonzalez-Gomez’s Bio

Hector Monforte, MD — Hector Monforte, MD
Pediatric Pathology Anatomic Pathology

Dr. Monforte is the section chief of Anatomic Pathology and also supports the research mission of Johns Hopkins All Children’s by serving as director of the Tissue-Based Diagnosis and Research Core and the Johns Hopkins All Children’s Pediatric Biorepository. He earned his medical degree from the Universidad Autónoma de Guadalajara School of Medicine in Mexico. He completed his anatomic pathology residency at Jackson Memorial Hospital in Miami, Florida, and fellowships at The University of Texas M.D. Anderson Cancer Center in Houston and at the Children's Hospital Los Angeles.
View Hector Monforte’s Bio

Psychology

Jennifer Katzenstein, PhD — Jennifer Katzenstein, PhD
Neuropsychology

Dr. Katzenstein is the director of psychology, neuropsychology and social work, at Johns Hopkins All Children’s Hospital. Previously, Dr. Katzenstein was a private practitioner and Assistant Professor of Neurology at Indiana University School of Medicine/Riley Hospital for Children in Indianapolis where she provided neuropsychological evaluations, consultations and academic coaching for children and adolescents. After graduating from Indiana University Purdue University Indianapolis, she completed a pediatric internship and fellowship at Texas Children's Hospital/Baylor College of Medicine. Dr. Katzenstein is board certified in pediatric neuropsychology and clinical neuropsychology.
View Jennifer Katzenstein’s Bio

ARNPs & PAs

Susan Buffington, APRN — Susan Buffington, APRN
Nurse Practitioner Pediatric Radiology

View Susan Buffington’s Bio

Stephanie DiGiovanni, PA-C — Stephanie DiGiovanni, PA-C
Physician Assistant Plastic Surgery

Stephanie DiGiovanni is a physician assistant in the pediatric plastic and reconstructive surgery program at Johns Hopkins All Children’s. She joined the hospital staff in 2022. Prior to joining Johns Hopkins All Children’s, she worked in trauma surgery/acute care surgery critical care at Regional Medical Center at Bayonet Point in Hudson, Florida. She earned her Master of Science in physician assistant studies from South College in Knoxville, Tennessee.
View Stephanie DiGiovanni’s Bio

Heather King, APRN — Heather King, APRN
Nurse Practitioner Pediatric Cardiology

View Heather King’s Bio

Aleshia Pringle, APRN — Aleshia Pringle, APRN
Nurse Practitioner Plastic and Reconstructive Surgery

Aleshia Pringle is an advanced practice registered nurse (APRN) in the cleft and craniofacial program at Johns Hopkins All Children’s Hospital. Her clinical focus is to provide comprehensive care for patients and families with cleft and craniofacial differences, as well as pediatric vascular malformations and general pediatric plastic surgery care. She is also interested in multidisciplinary collaboration for cleft lip and palate, Pierre Robin sequence, preparing and assisting in postoperative recovery and optimizing patient and family access to pediatric healthcare.
View Aleshia Pringle’s Bio

Michelle Walker, APRN — Michelle Walker, APRN
Nurse Practitioner Pediatric Surgery

View Michelle Walker’s Bio