The goal of this observational study is to learn about the pneumothorax risk associated with the Pleural-Depth-Trimmed Hookwire (PDTH) technique in patients undergoing Preoperative CT-Guided Lung Nodule Localization (POCTGL). The main question it aims to answer is: Does the specialized PDTH technique increase the risk of iatrogenic pneumothorax compared to dye-only localization in a setting utilizing advanced puncture guidance?. Participants were a retrospective cohort of patients who underwent POCTGL procedures between 2015 and 2022, and their procedural data and post-procedural complications were analyzed.

The unique contribution of this retrospective cohort study lies in its rigorous evaluation of an institutional, multi-component protocol for Preoperative CT-Guided Lung Nodule Localization (POCTGL), specifically focusing on the safety of the Pleural-Depth-Trimmed Hookwire (PDTH) technique when used in conjunction with the Laser Angle Guide Assembly (LAGA) system.

Specialized Intervention Technique Pleural-Depth-Trimmed Hookwire (PDTH)

Technical Rationale: The PDTH technique was developed to mitigate the high pneumothorax risk (historically reported up to 35%) associated with standard hookwires. This risk is hypothesized to result from the excessive length of the traditional hookwire protruding from the chest wall, causing friction and pleural trauma during patient movement and respiration.

Execution: The standard localization hookwire (Hawkins II) is pre-trimmed prior to insertion. Its length is adjusted to only exceed the measured distance from the pleural surface to the target nodule by a minimal margin (5 mm∼10 mm), effectively eliminating the long, protruding segment.

Combined Approach: For deep lesions (typically >30 mm from the pleura), the PDTH is used in combination with a dual patent blue vital dye (PBV) tattooing strategy, providing multiple locational markers for the subsequent Video-Assisted Thoracoscopic Surgery (VATS).

Laser Angle Guide Assembly (LAGA)

The protocol incorporates the LAGA system, a device that provides visual, objective guidance for the needle trajectory. This system's primary benefit is to improve the accuracy of the initial puncture, which directly correlates with reducing the number of puncture attempts, a critical modifiable risk factor for pneumothorax confirmed by this study.

Rigorous Statistical Methodology

To provide a robust comparison despite the non-randomized, observational nature of the data, the study employed advanced statistical methods:

Generalized Estimating Equations (GEE): Used to identify independent risk factors for pneumothorax across the entire cohort. GEE was crucial for accounting for the non-independence of observations, as many patients underwent multiple procedures or had multiple nodules localized within a single session.

Propensity Score Matching (PSM): Utilized to control for selection bias inherent in marker choice (PDTH vs. dye-only). PSM was performed strictly on the first-localized nodule from each procedure, employing a 1:1 nearest-neighbor match, adjusted for key confounding variables like lobe location and specific patient position.

Clinical Implications

The study reports an overall iatrogenic pneumothorax rate of 5.6%, which is substantially lower than historical data, supporting the efficacy of the comprehensive protocol. Crucially, both GEE and PSM analyses confirmed that the use of the PDTH technique was not associated with an increased risk of pneumothorax compared to the dye-only localization group (PSM comparison: p=0.662), validating the specialized, modified hookwire technique as a safe option within this low-risk protocol.

Inclusion Criteria:

• Consecutive series of patients who underwent Preoperative Computed Tomography-Guided Lung Nodule Localization (POCTGL) at our medical center between September 2015 and January 2022.
• All included procedures were performed in patients who subsequently underwent Video-Assisted Thoracoscopic Surgery (VATS) lung resection on the same day.

Exclusion Criteria For the primary Generalized Estimating Equations (GEE) analysis:

• Nodules localized after a pneumothorax event occurred (n=59) were excluded.

Exclusion Criteria For the Propensity Score Matching (PSM) analysis:

• Nodules localized after a pneumothorax event (n=59).
• Nodules that were not the first localized nodule during the POCTGL procedure (n=495).
• Nodules associated with a previous ipsilateral VATS (n=16).

The final analysis cohort included 1,072 POCTGL procedures. The procedures resulted in 1,567 evaluable lung nodules after the initial exclusion.

Demographics: The median age was 55 years (IQR, 48-63). The cohort was predominantly women (74.6%) and nonsmokers (86.3%).

Lesion Characteristics: The median lesion size was 6.5 mm (IQR, 5.0-8.0) , with a median depth from the pleura of 19 mm (IQR, 10.0-30.0).

Procedure Type: Most procedures (90.3%) were for initial VATS , and the majority involved a single lesion (65.5%).

The individual participant data (IPD) are not publicly available due to patient confidentiality and ethical restrictions. However, de-identified IPD supporting the findings of this study will be made available upon request. Researchers who meet the criteria for access to confidential data may submit requests to the Institutional Review Board (IRB) of Chung Shan Medical University Hospital, Taichung, Taiwan, for review and approval.

Start Date: Upon request, 90 days after publication. End Date: Five years following study publication.

Access to the de-identified Individual Participant Data (IPD) and supporting documentation (e.g., Statistical Analysis Plan and Analytic Code ) will be considered for qualified researchers who meet the criteria for accessing confidential data.

Who: Qualified researchers who submit a detailed research proposal and sign a data access agreement.

What: De-identified IPD supporting the findings, along with the study protocol and statistical analytic code.

How: Requests must be submitted to the Institutional Review Board (IRB) of Chung Shan Medical University Hospital, Taichung, Taiwan, for formal review and approval. Access will be granted following a privacy risk assessment by the IRB and/or relevant institutional committees.