Body Stalk Anomalies in Pigs: Current Trends and Future Directions in Classification

Abstract

Simple Summary: Body stalk anomaly (BSA) is a rare birth defect that affects the body wall, skeleton, and umbilical cord. To better understand and describe these anomalies, researchers studied cases in pigs and created a new classification system. This system divides BSA into eight types based on the specific combinations of defects, such as body wall openings, umbilical cord problems, and skeletal deformities, such as curved spines or missing bones. For example, some types include problems with both the spine and limbs, while others may affect the sternum or ribs. A related condition, limb-body wall complex (LBWC), is often treated as a separate category, but this study found that all piglets with limb defects also had spinal problems, so they were grouped into a new classification called the spinal-limb-body wall complex (SPLBWC). Other classifications were created for defects affecting the spine, sternum or both. This system helps doctors and researchers describe these abnormalities more accurately, making them easier to diagnose, study, and, where possible, treat. By improving our understanding of these conditions in animals, we can also learn more about similar defects in humans and find better ways to help those affected Abstract: Body stalk anomaly (BSA) is a complex congenital condition characterized by defects in the body wall, skeletal abnormalities, and an absent or abnormal umbilical cord (UC). A classification system for BSA, based on wall and skeletal abnormalities, is proposed and includes eight types observed in porcine models. These classifications consider combinations of thoracoabdominoschisis, abdominoschisis, anal atresia, genitourinary anomalies, and skeletal defects, including extreme retroflexion, scoliosis, vertebral agenesis, hemivertebrae, and thoracic or limb anomalies. While previous studies often treat limb-body wall complex (LBWC) as a separate condition, this study includes cases with co-occurring limb and spinal defects in a new classification, spinal-limb-body wall complex (SPLBWC). Additional skeletal classifications—spine-body wall complex (SPBWC), sternal-body wall complex (STBWC), and sternal-spinal-body wall complex (SSBWC)— are introduced to account for variations in structural anomalies. Nonstructural skeletal anomalies such as deformities, amputations, and arthrogryposis are excluded from the structural classifications. This comprehensive system, based on existing human and porcine models, provides a framework for the systematic categorization of BSA variations. Such an approach supports accurate diagnosis, enhances understanding of developmental defects, and improves clinical management and research outcomes in both veterinary and human medicine

La anomalía del tallo corporal (BSA) es una afección congénita compleja caracterizada por defectos en la pared corporal, anomalías esqueléticas y un cordón umbilical (CU) ausente o anormal. Se propone un sistema de clasificación del BSA, basado en las anomalías de la pared y el esqueleto, que incluye ocho tipos observados en modelos porcinos. Estas clasificaciones consideran combinaciones de toracoabdominosquisis, abdominosquisis, atresia anal, anomalías genitourinarias y defectos esqueléticos, como retroflexión extrema, escoliosis, agenesia vertebral, hemivértebras y anomalías torácicas o de las extremidades. Mientras que los estudios anteriores suelen tratar el complejo extremidades-pared corporal (LBWC) como una afección independiente, este estudio incluye casos con defectos concurrentes de las extremidades y la columna vertebral en una nueva clasificación, complejo columna-extremidades-pared corporal (SPLBWC). Se introducen clasificaciones esqueléticas adicionales -complejo columna--pared corporal (SPBWC), complejo esternal pared corporal (STBWC) y complejo esternal columna -pared corporal (SSBWC)- para tener en cuenta las variaciones en las anomalías estructurales. Las anomalías esqueléticas no estructurales, como deformidades, amputaciones y artrogriposis, se excluyen de las clasificaciones estructurales. Este sistema integral, basado en modelos humanos y porcinos existentes, proporciona un marco para la categorización sistemática de las variaciones del BSA. Este enfoque permite un diagnóstico preciso, mejora la comprensión de los defectos del desarrollo y mejora la gestión clínica y los resultados de la investigación tanto en medicina veterinaria como humana.