# Simple X-ray Metric Predicts Postoperative Course After Spontaneous Pneumothorax Surgery

## TL;DR

A simple X-ray measurement can predict how long a chest tube will be needed after surgery for spontaneous pneumothorax.

## Contribution

Introduces a new radiological thoracic index as a predictor for postoperative chest tube duration in spontaneous pneumothorax patients.

## Key findings

- Higher RT index correlates with longer chest tube duration (≥5 days).
- Age and postoperative PAL are independent predictors of the RT index.
- RT index shows no significant difference among patient groups based on surgery reasons.

## Abstract

Background: Predicting postoperative outcomes in patients with spontaneous pneumothorax (SP) remains clinically valuable. This study investigates whether a radiological thoracic (RT) index, calculated as the chest height-to-width ratio on posteroanterior (PA) chest radiographs (CXR), can serve as a predictor after SP surgery.

Methods: In this retrospective study, 195 patients who underwent surgery for SP were included. Patients were grouped according to surgery reasons as recurrence (n=101), preoperative persistent air leak (PAL) (n=58), and bilateral pneumothorax history (n=36). The RT index was calculated on PA CXRs using the involved side (right side for bilateral cases). Comparisons were made between patient groups, and linear regression was used to determine independent predictors of the RT index.

Results: The mean RT index was 2.41±0.33. The RT index was significantly higher in patients with chest tube duration ≥5 days (2.49±0.34 vs. 2.34±0.31, p<0.001). Age was negatively correlated with the RT index (r=-0.459, p<0.001), while chest tube duration after surgery positively correlated (r=0.170, p=0.017). Multivariate regression identified age and postoperative PAL as independent predictors of the RT index (p<0.001). No significant difference in the RT index was found among recurrence, preoperative PAL, or bilateral pneumothorax history groups.

Conclusion: The RT index derived from routine CXRs may help predict prolonged chest tube duration in patients undergoing surgery for SP. This simple radiological metric could contribute to perioperative risk stratification.