# The Impact of Post-Operative Phrenic Nerve Dysfunction on Lung Function Parameters and Long-Term Outcomes After Lung Transplantation

## TL;DR

This study examines how phrenic nerve dysfunction after lung transplants affects lung function and recovery, finding it delays hospital stays but doesn't impact long-term survival.

## Contribution

The study provides the first long-term analysis of post-operative phrenic nerve dysfunction's impact on lung function and survival after lung transplantation.

## Key findings

- Patients with phrenic nerve dysfunction had significantly longer ICU and hospital stays compared to controls.
- Phrenic nerve dysfunction led to lower total lung capacity early after transplantation.
- Despite initial lung function differences, long-term survival was not affected by phrenic nerve dysfunction.

## Abstract

A rare but important complication after lung transplantation (LTx) is postoperative phrenic nerve dysfunction (PND). Diaphragmatic plication (DP) is a well-established treatment option for PND, however, the long-term effect of PND and DP on lung function parameters and survival after LTx are currently unknown. We retrospectively reviewed 1400 LTx recipients transplanted at Medical University of Vienna between 01/2003 and 12/2022. Fluoroscopy and/or phrenic nerve conduction studies confirmed PND when chest radiographs after extubation showed a unilateral heightened diaphragm. We identified 25 patients with post-operative PND, of whom 12 underwent DP. The remaining 1,375 patients served as a control group. Median ICU-stay and hospital-stay were significantly longer in the PND groups (DP: 20 and 57 days; non-DP: 27 and 43 days; control group: 7 and 25 days; P = 0.001/P < 0.001). PND led to consistently lower %TLC in lung function tests performed within the first three years after LTx. DP was associated with lower %FEV1.0 early after LTx but it aligned to %FEV1.0 of the other groups during follow-up. Although PND significantly affected postoperative recovery after LTx, it did not impair long-term survival outcomes.

Graphs display the impact of post-operative phrenic nerve dysfunction on lung function and survival after lung transplantation. The left graphs show mean total lung capacity and FEV1.0 over 36 months post-transplant, comparing DP (red), Non-DP (blue), and control (black) groups. The right graph depicts overall survival over 20 years, with similar group comparisons. DP consistently shows lower values in lung function tests. The survival analysis reveals no significant difference, with a p-value of 0.74.