Staged sternal distraction for early thoracic expansion in Shwachman-Diamond syndrome

Shwachman-Diamond syndrome (SDS) is a rare inherited multisystem disorder with variable skeletal involvement; severe neonatal thoracic dystrophy is uncommon but can cause thoracic insufficiency and mimic Jeune syndrome. We report staged sternal distraction in a 5-month-old infant with a severely constricted thorax, pulmonary hypoplasia, refractory pulmonary hypertension, tracheostomy-dependent respiratory failure and an iatrogenic posterior tracheal wall injury. Subsequent trio long-read genome sequencing identified compound heterozygous pathogenic variants in SBDS, c.183_184delinsCT (p.Lys62Ter), inherited paternally, and c.258+2T>C, inherited maternally, establishing a molecular diagnosis of SDS. At presentation, the chest circumference measured 36cm, compared with an age-expected value of 41cm. The patient underwent staged median sternotomy distraction followed by stabilisation with custom fibular allograft struts. At approximately 3 months, chest circumference had increased to 41cm, peak inspiratory pressures had decreased from 40-50cm H₂O to the mid-20cm H₂O range, pulmonary hypertension was no longer evident on echocardiography, and the tracheal injury had healed. At 6 months, he remained on home mechanical ventilation, with peak inspiratory pressures in the upper 20cm H₂O range. To our knowledge, operative thoracic expansion specifically for SDS-associated thoracic insufficiency has not previously been described. In carefully selected infants with severe thoracic insufficiency who are not yet candidates for conventional thoracic reconstruction, staged sternal distraction may serve as an interim strategy to achieve meaningful thoracic expansion.