Dr. Joseph Greene

Gina Adrales, M.D., M.P.H., joins the Johns Hopkins Department of Surgery as Director of the Division of Minimally Invasive Surgery, Director of the Minimally Invasive Surgery Training and Innovation Center, and Co-Director of the Johns Hopkins Bariatric Surgery Fellowship. Her areas of clinical expertise include gastroesophageal reflux disease (GERD), gallbladder disease, achalasia, splenectomy (spleen removal), benign gastric and intestinal surgery, bariatric surgery, and open and laparoscopic hernia repair (inguinal, ventral, incisional, umbilical, hiatal, paraesophageal). Dr. Adrales has been named an associate member of the American College of Surgeons' Academy of Master Surgeon Educators. Awardees are recognized for having devoted their careers to surgical education and are considered premier leaders in their respective fields. Prior to joining Johns Hopkins, Dr. Adrales was on faculty at Dartmouth where she directed the Surgery Clerkship, the Hernia Surgery Center, and the Bariatric Surgery Program. During her tenure at Dartmouth, she earned her Masters of Public Health at The Dartmouth Institute for Health Policy and Clinical Practice. She received her undergraduate degree from the College of William and Mary and her medical degree from the University of Virginia. She completed her residency at the Carolinas Medical Center and a research and clinical fellowship in minimally invasive surgery at the University of Kentucky before her first faculty appointment at the Medical College of Georgia. A national leader in hernia surgery, Dr. Adrales serves on the Executive Council of the Americas Hernia Society and previously served on the Executive Council of the Americas Hernia Society Quality Collaborative to improve the safety and quality of hernia surgery. She is actively involved in a number of committees for the Society of American Gastrointestinal and Endoscopic Surgeons including various roles in surgical education, the development of the Fundamentals of Endoscopic Surgery and an innovative interactive hernia surgery education module. Dr. Adrales’ research interests include health services research, clinical outcomes and quality improvement in minimally invasive foregut surgery, bariatric and metabolic surgery, and abdominal wall reconstruction. She has presented her work regionally, nationally, and internationally. Dr. Adrales is rated as a Distinguished provider by MediFind in the treatment of Hernia. Her top areas of expertise are Hernia, Hiatal Hernia, Gastroparesis, Gastrectomy, and Sleeve Gastrectomy.

Hien T. Nguyen, M.D., FACS, is an assistant professor of surgery at The Johns Hopkins University School of Medicine. After completing an undergraduate education at University of California, Davis, Dr. Nguyen earned his medical degree at University of California, Davis School of Medicine. He completed training in general surgery at University of California, San Francisco East Bay, followed by a fellowship in advanced laparoscopic and bariatric surgery at The Johns Hopkins University School of Medicine. Dr. Nguyen is an expert in single-incision surgery, robotic surgery and laparoscopic bariatric surgery (which includes Roux-en-Y gastric bypass, adjustable gastric bands, sleeve gastrectomy and duodenal switch). He was instrumental in helping to establish the single-incision approach for laparoscopic surgery at The Johns Hopkins Medical Institutions. Dr. Nguyen also specializes in the repair of complex hernias and abdominal wall reconstruction, utilizing minimally invasive and advance techniques. He also works with students and residents in surgical education and biomedical engineering. Dr. Nguyen currently is an active member of many academic organizations, including the American Society for Metabolic and Bariatric Surgery, the Society for Surgery of the Alimentary Tract, the Society of American Gastrointestinal and Endoscopic Surgeons, the American Hernia Society and the American College of Surgeons. His research interests include clinical outcomes in hernia surgery, critical care medicine, bariatric surgery and metabolic syndrome. Dr. Nguyen is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Hernia, Umbilical Hernia, Obesity, Sleeve Gastrectomy, and Gastrectomy.

Dr. Brett Parker is a general surgeon and fellowship-trained minimally invasive foregut and bariatric surgeon. He is an Assistant Professor of Surgery at Johns Hopkins and also the Program Director for the Johns Hopkins Advanced GI and Minimally Invasive Surgery Fellowship Program. Dr. Parker is an expert in minimally invasive surgical techniques including advanced laparoscopy and robotic surgery, as well as therapeutic flexible endoscopy. He is interested in promoting the evolving indications for surgical repair of hiatal hernias, as well as adjunct procedures surgeons can use to reduce recurrence rates. He offers a wide range of interventions for GERD, including innovative endoscopic therapies, and promotes early surgical referral to discuss and tailor therapy to individual patient circumstances. Dr. Parker also has a robust abdominal wall reconstruction and weight loss surgery practice. He is widely published on the surgical outcomes of foregut surgery, emerging technologies, and innovation, as well as surgical simulation and skills transfer. Dr. Parker has consistently been selected as a Washingtonian Magazine Top Doctor in 2023, 2024, and 2025. As a member of the Johns Hopkins Division of Minimally Invasive Surgery in the Greater Washington Area, Dr. Parker is dedicated to the best, individualized, patient outcomes. Learn more about Dr. Parker and his partners within the Johns Hopkins Division of Minimally Invasive Surgery, the Johns Hopkins Heartburn Center and the Johns Hopkins Motility and Neurogastroenterology Center. Dr. Parker is rated as an Advanced provider by MediFind in the treatment of Hernia. His top areas of expertise are Hiatal Hernia, Hernia, Congenital Diaphragmatic Hernia, Endoscopy, and Gallbladder Removal.