Long-term efficacy of diaphragm plication on the pulmonary function of adult patients with diaphragm paralysis: a retrospective cohort study.

Background: Diaphragm plication is an effective and safe procedure for patients with symptomatic, acquired diaphragm paralysis. Improvements in dyspnea scores, ventilation perfusions and exercise capacity has been reported. Unfortunately, no continuous measurements of lung functions at 3 to 5 years' follow-up have been recorded. This study was designed to assess the long-term effects and potential mechanism of diaphragm plication for non-malignant diaphragmatic paralysis patients, especially in relation to patients' subjective and objective improvement.

Methods: This study retrospectively reviewed the medical records of 36 adult patients with diaphragmatic paralysis treated with diaphragm plication by thoracotomy at the Tianjin Chest Hospital from 1992 to 2016. The adult patients were carefully selected based on etiology and a combination of clinical manifestation, pulmonary function testing, and chest imaging characteristics. Patients' preoperative pulmonary functions, forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in the supine and sitting positions were recorded. Survival information was obtained at follow-ups continuously conducted with 8 patients for 4 years after surgery.

Results: The main symptoms were lifestyle-limiting dyspnea and orthopnea, and a few patients also had digestive symptoms. The mean body mass index of patients was 26.02±2.19. The etiology was trauma in 3 patients, and surgery in 5 patients. The operated diaphragm was found to be lower than the contralateral diaphragm in the first 3 months after surgery; however, from the 4th month, both sides of the diaphragm were basically at the same level. Additionally, 31 patients (86.11%) showed an improvement in subjective symptoms, especially digestive symptoms preoperatively. The averages of FVC and FEV1 increased by 26.8% and 24.3%, respectively, in patients 6 months after diaphragmatic plication, and from the 18th month, lung function declined gradually, returning to preoperative levels in the 4th year.

Conclusions: Diaphragmatic plication can obviously improve the lung function and subjective symptoms of patients in the short term, but from the 18th month, lung function declined gradually to preoperative levels in the 4th year indicated that its long-term effect on lung function is poor. The major purpose of diaphragmatic plication is to balance the position of the heart and abdominal organs, and thus to improve patients' symptoms to a certain extent.