A rare case of complete agenesis of the left hemidiaphragm in a 17-year-old male: modified surgical reconstruction and literature review.

Introduction and importance: Diaphragmatic agenesis (DA) is the most severe and uncommon form of congenital diaphragmatic defects, characterized by the complete or partial absence of the diaphragm. Most affected neonates do not survive respiratory failure secondary to pulmonary hypoplasia, making survival beyond infancy exceptionally rare. We report a 17-year-old male with complete left hemidiaphragmatic agenesis successfully managed with prosthetic reconstruction and present an updated review of adolescent and adult cases in the literature over 77 years. Case presentation: A 17-year-old male presented with a history of progressive exertional dyspnea and intermittent vomiting. Clinical findings included markedly reduced air entry in the left hemithorax and audible bowel sounds. Chest radiograph and CT scan demonstrated abdominal viscera in the left hemithorax. Intraoperatively, we noted a complete absence of the left hemidiaphragm, and a polypropylene mesh was used to reconstruct a neodiaphragm. Postoperative recovery was uneventful, and he remained asymptomatic and resumed his recreational activities. Clinical discussion: Through a comprehensive literature search across PubMed, Web of Science, Scopus, and Google Scholar, we identified only 23 cases of DA in adolescents and adults over 77 years. There was an equal distribution between left- and right-sided defects (11 each), with one bilateral case. Surgical repair using synthetic mesh was the predominant management approach (10/23). Conclusion: Although exceptionally rare beyond infancy, DA should remain a differential diagnosis in patients presenting with chronic dyspnea and showing pulmonary hypoplasia, mediastinal shift, and intrathoracic bowel on imaging. Timely surgical intervention, when indicated, can prevent visceral complications.