Thoracic mediastinal-occupying ratio predicts recovery and prognosis after lung transplantation

OBJECTIVES: Even after transplantation of favourable donor lungs, some recipients require prolonged weaning from mechanical ventilation, indicating a poor prognosis. We investigated the effects of prolonged mechanical ventilation (PMV) for >14 days on the recovery and survival of patients who underwent cadaveric lung transplantation in relation to their physical traits. METHODS: We retrospectively reviewed patients who underwent cadaveric lung transplantation (age >= 15 years) at a single centre between April 2015 and December 2020 and classified them into PMV and non-PMV groups (>14 and <= 14 days of mechanical ventilation postoperatively, respectively). The factors predicting PMV comprised clinical factors (e.g. marginal donor) and physical features, namely flat chest, narrow fourth intercostal space (length, <5 mm), mediastinal shift, thoracic mediastinal-occupying ratio (TMOR) >40% and sarcopenia, according to the logistic regression analysis. The log-rank test was used to examine the association between TMOR >40% and 3-year prognosis. RESULTS: The PMV group comprised 17 (33%) of 51 recipients. Multivariable logistic analysis showed that the TMOR >40% (odds ratio, 7.3; 95% confidence interval, 1.3-40.1; P = 0.023) was an independent preoperative predictive factor for PMV postoperatively. Stepwise analysis revealed intraoperative extracorporeal membrane oxygenation and reoperation as postoperative predictive factors in addition to TMOR >40%. Recipients with TMOR >40% had significantly worse 3-year survival than other recipients (71.2% vs 100.0%, respectively; P = 0.008). CONCLUSIONS: Recipients with a TMOR >40% may be long-term ventilator dependent and have a poor prognosis.

Automated summary

This study found that prolonged mechanical ventilation for more than 14 days after cadaveric lung transplantation can negatively impact the recovery and survival of patients. Factors such as flat chest, mediastinal shift, and a thoracic mediastinal-occupying ratio (TMOR) greater than 40% were identified as predictive factors for prolonged mechanical ventilation. Patients with TMOR greater than 40% had significantly worse 3-year survival compared to others.