Fellowship-trained at Children's Hospital Los Angeles in pediatric surgery, surgical critical care, and minimally invasive surgery after completing general surgery residency at UC San Diego, Shannon L. Castle, MD practices pediatric surgery at the UC San Diego Health campus at 200 W Arbor Dr in Hillcrest. The site is anchored by Hillcrest Medical Center at UC San Diego Health, the region's only Level I trauma center and the primary acute-care hospital serving adolescent pediatric surgical admissions on the UCSD side of the UCSD-Rady Children's academic partnership. Her clinical and research focus covers pediatric trauma, surgical critical care, and nutrition, with peer-reviewed work published in the Journal of Pediatric Surgery and the Journal of Surgical Research. Preoperative endocrine workups for abdominal tumor cases and metabolic comorbidities are frequently coordinated with pediatric subspecialty clinics such as Children's Healthcare Pediatric Endocrinology, which keeps multi-disciplinary care consolidated on the Hillcrest corridor. The highest-complexity cases are minimally invasive neonatal thoracoscopic and laparoscopic procedures including single-port appendectomies, thymectomies, and congenital anomaly repairs, where the scar footprint and recovery window separate surgeons with formal MIS fellowship training from general pediatric surgical practices.