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.
