Unilateral diaphragmatic dysfunction can cause exertional and postural dyspnoea, along with sleep-related breathing disturbances. Diaphragm plication alleviates daytime symptoms, but its effects on sleep have not been evaluated in detail.

We analysed prospectively collected observational data in 12 patients undergoing surgical plication for unilateral diaphragmatic dysfunction. Standardised pre- and postoperative assessments included ratings of exertional dyspnoea, orthopnoea and antepnoea (D-VAS), quality of life (VSRQ), spirometry (sitting and supine), transdiaphragmatic twitch pressures, and polysomnography (PSG). Sleep-disordered breathing was evaluated using standard PSG indices including the obstructive apnoea–hypopnoea index (oAHI), measured globally and during REM.

Following plication, dyspnoea decreased and orthopnoea and antepnoea were nearly abolished (p = 0.0123 and p = 0.0001, respectively). VSRQ improved (p = 0.0078). Supine vital capacity rose from 52.5% to 75.0% predicted (p = 0.0010), and supine VC drop decreased from 15.1% to 2.65% (p = 0.0068). Twitch pressures increased significantly. oAHI decreased from 15.5 to 8.5 events·h⁻¹ (not significant after multiplicity correction). REM AHI decreased from 43.0 [24.5–66.9] to 19.0 [11.5–23.3] events·h⁻¹ (p = 0.0020), and REM hypopnoea index from 19.5 to 11.0 (p = 0.0098). Strong correlations were found between REM AHI changes and both FRC and expiratory reserve volume (ERV).

In patients with unilateral diaphragmatic dysfunction, diaphragm plication is associated with improved REM-related obstructive events. This may relate to lung volume restoration. These exploratory findings suggest that prospective studies are needed to determine the usefulness of systematic pre-post plication PSG for patient selection and outcome evaluation.