# Postoperative Pulmonary Function and Structural Remodelling After Lobectomy in Patients With and Without Chronic Obstructive Pulmonary Disease

## TL;DR

This study shows that COPD patients maintain better postoperative lung function than predicted, while non-COPD patients experience increased lung volume changes after lobectomy.

## Contribution

The study introduces a novel integration of functional and structural 3D-CT indexes to evaluate postoperative lung remodelling after lobectomy.

## Key findings

- COPD patients had a significantly higher measured-to-predicted FEV1.0 ratio compared to non-COPD patients.
- Non-COPD patients showed a significant increase in low-attenuation area after surgery.
- Structural remodelling parameters like D-value and LAA provide insights beyond conventional function prediction.

## Abstract

Quantitative assessment of lung structure provides insights beyond conventional postoperative function prediction. This study examined how preoperative chronic obstructive pulmonary disease (COPD) status and emphysema distribution influence postoperative pulmonary function and structural remodelling using 3-dimensional computed tomography (3D-CT) cluster analysis.

We retrospectively analysed 426 lobectomy cases performed between 2018 and 2023. Patients were stratified into the COPD and non-COPD groups. Predicted postoperative FEV1.0 was estimated using 3D-CT volumetry, and the measured-to-predicted FEV1.0 ratio (MPFR) was calculated. Structural parameters, including D-value (reflecting alveolar complexity) and low-attenuation area (LAA), were measured pre- and postoperatively using 3D-CT. MPFR, % change in D-value (%D-value), and LAA (%LAA) were compared between the groups using Mann-Whitney U tests. Subgroup analysis was performed based on whether the resected lobe had a higher or lower D-value than the whole lung.

Patients with COPD exhibited a significantly higher MPFR than those without COPD (117.9% vs 110.7%, P < .001). %D-value did not differ significantly between the groups (99.7% vs 98.1%, P = .476), whereas %LAA was significantly higher in non-COPD patients (134.9% vs 117.6%, P = .005). In subgroup analyses according to the presence of emphysematous resected lobes, MPFR and %D-value did not differ between the groups, and no significant difference in %LAA was observed.

Patients with COPD maintain better-than-predicted postoperative function without additional structural loss, whereas non-COPD patients show volume-driven increases in LAA. Integrating functional and structural 3D-CT indexes—MPFR, D-value, and LAA—enables a comprehensive evaluation of postoperative lung remodelling, potentially improving risk stratification and surgical planning.

G-441; approved on May 12, 2025.

Chronic obstructive pulmonary disease (COPD) is a common comorbidity in patients undergoing lung resection and is associated with an increased perioperative risk and decreased pulmonary function.