Quantitative Analysis of Changes in the Thoracic Anatomy over Time after Pneumonectomy Using Computed Tomography.

OBJECTIVES

The rate and extent of hemithorax volume reduction on the operated side, corresponding compensatory volume increase on the contralateral side, and mediastinal angle shift following pneumonectomy have not been quantitatively analysed. This study aimed to quantify these time-dependent changes in thoracic anatomy after pneumonectomy.

METHODS

Patients who underwent pneumonectomy between April 2003 and June 2019 were retrospectively included. The volume of each hemithorax and the mediastinal shift angle were quantified using computed tomography scans taken pre- and postoperatively (6 months, 1, 2, and 3 years after surgery).

RESULTS

Finally, 119 patients (median age, 58.5 years; 95 men) were evaluated. The pneumonectomy site volume decreased to 25% and 37% of the original volume in the left and right pneumonectomy, respectively, over 3 years, with 21%-24% hyperinflation in the non-operated hemithorax. Mediastinal shifting towards the pneumonectomy side was observed as an increased angle (from 7.1° to 21.4° for the left pneumonectomy and from 4.4° to 20.3° for the right pneumonectomy). Volume reduction was significant until the first 6 months for right pneumonectomy and 1 year for left pneumonectomy (all P < .05), while hyperinflation and mediastinal shifting stabilized after 6 months. Left pneumonectomy showed a more abrupt volume decrease than right pneumonectomy during the observed period (all P < .05).

CONCLUSIONS

Significant anatomical changes occur within the first 6 months after a pneumonectomy. Thereafter, the magnitude of change decreases, and the thoracic structures reach a steady state by 2 to 3 years postoperatively.

CLINICAL REGISTRATION NUMBER: None.