The relationship between spinal structure and respiratory function has been coined as thoracic insufficiency syndrome and is defined as the inability of the thorax to support normal respiratory function or lung growth. Little is known about what supports this relationship in untreated nonambulatory myelomeningocele patients.
A prospective cross-sectional study of nonambulatory myelodysplasia patients was performed. Anatomic, radiographic, and functional parameters were evaluated to validate the respiratory–spinal structure relationship. Thirty-one patients diagnosed with nonambulatory myelomeningocele fulfilled the inclusion criteria.
The imaging study confirmed the spinal deformity. Lung functions measured in this patient population describe reduced lung volumes by CT lung volume reconstruction, reduced vital capacity by spirometry, and reduced total lung capacity by the nitrogen washout method. Together, these findings suggest moderate restrictive respiratory disease. The blood count study did not show evidence of anemia or other blood disturbances. Echocardiogram analysis did not show pulmonary hypertension in any patient.
The data validate the relationship between spinal structure and lung function. However, there is no simple structural feature that could help to diagnose thoracic insufficiency syndrome. Thus, the diagnosis continues to be based on a combination of clinical findings and radiological and respiratory function evaluations.
From the Pediatric Orthopaedic Department, Hospital de la Concepción San German Puerto Rico (Dr. Ramírez), the Biology Department, Inter-American University, San German, Puerto Rico (Mr. Valentín), the Division of Pulmonary Medicine, Pulmonary Function Testing Laboratory, The Children's Hospital of Philadelphia (Dr. Mayer), Department of Clinical Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA (Dr. Mayer), the Pulmonary and Sleep Medicine Division, Seattle Children's Hospital, Seattle, WA (Dr. Redding), the Respiratory Care (Ms. Rodríguez), the Respiratory Care and Intensive Care Unit, Hospital de la Concepción (Dr. Vélez), the Department of Cardiology, Hospital de la Concepción, San German, Puerto Rico (Dr. Jaume), the Public Health Program, Ponce Health Sciences University (Dr. Iriarte), and the Medicine Program, Ponce Health Sciences University, Ponce, Puerto Rico (Mr. Olivella).
Correspondence to Dr. Ramirez: firstname.lastname@example.org
Dr. Ramírez or an immediate family member serves as a board member, owner, officer, or committee member of the Children Spine Study Group. Dr. Mayer or an immediate family member is a member of a speakers' bureau or has made paid presentations on behalf of Biogen; serves as a paid consultant to Biogen, Bristol-Myers Squibb, FibroGen, Novartis, Pfizer, Roche, Santhe Pharmaceuticals, and Sarepta Therapeutics. None of the following authors or any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article: Mr. Valentín, Dr. Redding, Ms. Rodríguez, Dr. Vélez, Dr. Jaume, Dr. Iriarte, and Mr. Olivella.