Impact on pulmonary function from phrenic nerve transfer: a systematic review and meta-analysis

The aim of this study was to evaluate the respiratory consequences of phrenic nerve transfer (PNT) by analyzing clinical and paraclinical data across published studies.

The authors conducted a systematic review and meta-analysis of studies reporting respiratory outcomes after PNT. Only cases with documented postoperative follow-up and perioperative respiratory outcome were included. Data on patient demographics, diaphragm imaging, and pulmonary function test (PFT) values were extracted. Paired analyses were conducted in cases in which pre- and postoperative PFT data were available.

Among 617 patients with postoperative follow-up, 4.9% reported respiratory symptoms, and 67.4% of those assessed showed unilateral diaphragm paralysis. A meta-analysis of paired PFT data demonstrated a significant reduction in forced expiratory volume in 1 second and a nonsignificant reduction in forced vital capacity postoperatively. Fifteen (2.4%) of 617 patients reported mild but persistent respiratory symptoms.

Although PNT is effective for motor restoration, postoperative respiratory impairment, although typically mild, was observed in a subset of patients with follow-up data. These findings emphasize the need for long-term monitoring and careful patient selection in PNT, particularly in individuals with reduced pulmonary reserve.