Novel and Affordable Educational Phantom Model to Teach Trainees Ultrasound-Guided Transverse Abdominis Plane Block in Infants and Children
Jocelyn Y. Wong MD, Janice Y. Man MD, and Samuel Rodriguez MD
Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine; Lucile Packard Children’s Hospital Stanford, Stanford, CA
•Transverse abdominis plane (TAP) blocks in infants and children can reduce pain and opiate requirements after abdominal or inguinal surgery.
•While trainees can quickly master adult TAP blocks in as few as 4 trials, TAP blocks in infants can be more challenging. Diminutive infant structures and congenital anomalies can increase the risk of complications.
•Ultrasound studies note average normal fetal anterior abdominal wall thickness of 3.28 mm ± 0.37mm at 26-week gestation, to 7.94 mm ± 0.355mm in children 6-11 years old.
•While phantom TAP block ultrasound models exist for adults, no such model exists for infants.
•We developed a high-fidelity, low cost, phantom model that provided tactile and visual feedback on needle placement and spread of local anesthetic for a simulated infant TAP block under ultrasound guidance.
•Our model utilizes alternating layers of ballistic gel and rubber to simulate the planes of subcutaneous fat, external oblique, internal oblique, and transversus abdominis (Figure 1).
•A small diameter balloon filled with air mimics the peritoneal cavity.
•The gel layers are laid over the balloon and inserted in the eviscerated abdominal cavity of an infant doll.
•Inadvertent peritoneal injury is noted when the peritoneal cavity balloon pops, giving instantaneous feedback.
•There are advantages and disadvantages to our low cost, high fidelity, and reusable ultrasound model (Table 1).
•The model provide trainees with real-time feedback about needle placement and spread of local anesthetics.
•Future direction includes utilizing this novel model for trainee education curricula and faculty pediatric regional workshops.